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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

    Energy Technology Data Exchange (ETDEWEB)

    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

    DEFF Research Database (Denmark)

    Branzei, Simina; Michalak, Tomasz; Rahwan, Talal

    2012-01-01

    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...... 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. Modeling external constraints: Applying expert systems to nuclear plants

    International Nuclear Information System (INIS)

    Beck, C.E.; Behera, A.K.

    1993-01-01

    Artificial Intelligence (AI) applications in nuclear plants have received much attention over the past decade. Specific applications that have been addressed include development of models and knowledge-bases, plant maintenance, operations, procedural guidance, risk assessment, and design tools. This paper examines the issue of external constraints, with a focus on the use of Al and expert systems as design tools. It also provides several suggested methods for addressing these constraints within the Al framework. These methods include a State Matrix scheme, a layered structure for the knowledge base, and application of the dynamic parameter concept

  4. China's Coal: Demand, Constraints, and Externalities

    Energy Technology Data Exchange (ETDEWEB)

    Aden, Nathaniel; Fridley, David; Zheng, Nina

    2009-07-01

    This study analyzes China's coal industry by focusing on four related areas. First, data are reviewed to identify the major drivers of historical and future coal demand. Second, resource constraints and transport bottlenecks are analyzed to evaluate demand and growth scenarios. The third area assesses the physical requirements of substituting coal demand growth with other primary energy forms. Finally, the study examines the carbon- and environmental implications of China's past and future coal consumption. There are three sections that address these areas by identifying particular characteristics of China's coal industry, quantifying factors driving demand, and analyzing supply scenarios: (1) reviews the range of Chinese and international estimates of remaining coal reserves and resources as well as key characteristics of China's coal industry including historical production, resource requirements, and prices; (2) quantifies the largest drivers of coal usage to produce a bottom-up reference projection of 2025 coal demand; and (3) analyzes coal supply constraints, substitution options, and environmental externalities. Finally, the last section presents conclusions on the role of coal in China's ongoing energy and economic development. China has been, is, and will continue to be a coal-powered economy. In 2007 Chinese coal production contained more energy than total Middle Eastern oil production. The rapid growth of coal demand after 2001 created supply strains and bottlenecks that raise questions about sustainability. Urbanization, heavy industrial growth, and increasing per-capita income are the primary interrelated drivers of rising coal usage. In 2007, the power sector, iron and steel, and cement production accounted for 66% of coal consumption. Power generation is becoming more efficient, but even extensive roll-out of the highest efficiency units would save only 14% of projected 2025 coal demand for the power sector. A new wedge of

  5. Evolutionary prisoner's dilemma game on graphs and social networks with external constraint.

    Science.gov (United States)

    Zhang, Hui; Gao, Meng; Wang, Wenting; Liu, Zhiguang

    2014-10-07

    A game-theoretical model is constructed to capture the effect of external constraint on the evolution of cooperation. External constraint describes the case where individuals are forced to cooperate with a given probability in a society. Mathematical analyses are conducted via pair approximation and diffusion approximation methods. The results show that the condition for cooperation to be favored on graphs with constraint is b¯/c¯>k/A¯ (A¯=1+kp/(1-p)), where b¯ and c¯ represent the altruistic benefit and cost, respectively, k is the average degree of the graph and p is the probability of compulsory cooperation by external enforcement. Moreover, numerical simulations are also performed on a repeated game with three strategies, always defect (ALLD), tit-for-tat (TFT) and always cooperate (ALLC). These simulations demonstrate that a slight enforcement of ALLC can only promote cooperation when there is weak network reciprocity, while the catalyst effect of TFT on cooperation is verified. In addition, the interesting phenomenon of stable coexistence of the three strategies can be observed. Our model can represent evolutionary dynamics on a network structure which is disturbed by a specified external constraint. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    DEFF Research Database (Denmark)

    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. Structural optimization under overhang constraints imposed by additive manufacturing technologies

    Science.gov (United States)

    Allaire, G.; Dapogny, C.; Estevez, R.; Faure, A.; Michailidis, G.

    2017-12-01

    This article addresses one of the major constraints imposed by additive manufacturing processes on shape optimization problems - that of overhangs, i.e. large regions hanging over void without sufficient support from the lower structure. After revisiting the 'classical' geometric criteria used in the literature, based on the angle between the structural boundary and the build direction, we propose a new mechanical constraint functional, which mimics the layer by layer construction process featured by additive manufacturing technologies, and thereby appeals to the physical origin of the difficulties caused by overhangs. This constraint, as well as some variants, is precisely defined; their shape derivatives are computed in the sense of Hadamard's method, and numerical strategies are extensively discussed, in two and three space dimensions, to efficiently deal with the appearance of overhang features in the course of shape optimization processes.

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

    NARCIS (Netherlands)

    Tompson, M.K.; Moroni, G.; Vaneker, Thomas H.J.; Fadel, G.; Campbell, I.; Gibson, I.; Bernard, A.; Schulz, J.; Graf, P.; Ahuja, B.; Martina, F.

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  10. The Internal and External Constraints on Foreign Policy in India

    DEFF Research Database (Denmark)

    Schmidt, Johannes Dragsbæk

    2017-01-01

    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 be determined by negotiations, diplomacy or brute force but there i...... and outline the main approaches involved; to give an overview of how external factors impact foreign policy conduct and relate to India’s role in defining international norms and regulations; finally the paper gives some theoretical markers, suggestions and concluding remarks....

  11. 1-Skeletons of the Spanning Tree Problems with Additional Constraints

    Directory of Open Access Journals (Sweden)

    V. A. Bondarenko

    2015-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    Science.gov (United States)

    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Accurate Gravities of F, G, and K stars from High Resolution Spectra Without External Constraints

    Science.gov (United States)

    Brewer, John M.; Fischer, Debra A.; Basu, Sarbani; Valenti, Jeff A.; Piskunov, Nikolai

    2015-06-01

    We demonstrate a new procedure to derive accurate and precise surface gravities from high resolution spectra without the use of external constraints. Our analysis utilizes Spectroscopy Made Easy with robust spectral line constraints and uses an iterative process to mitigate degeneracies in the fitting process. We adopt an updated radiative transfer code, a new treatment for neutral perturber broadening, a line list with multiple gravity constraints and separate fitting for global stellar properties and abundance determinations. To investigate the sources of temperature dependent trends in determining log {\\mkern 1mu} g noted in previous studies, we obtained Keck HIRES spectra of 42 Kepler asteroseismic stars. In comparison to asteroseismically determined log {\\mkern 1mu} g our spectroscopic analysis has a constant offset of 0.01 dex with a rms scatter of 0.05 dex. We also analyzed 30 spectra which had published surface gravities determined using the a/{{R}*} technique from planetary transits and found a constant offset of 0.06 dex and rms scatter of 0.07 dex. The two samples covered effective temperatures between 5000 and 6700 K with log {\\mkern 1mu} g between 3.7 and 4.6.

  15. Anomic Strain and External Constraints: A Reassessment of Merton's Anomie/Strain Theory Using Data From Ukraine.

    Science.gov (United States)

    Antonaccio, Olena; Smith, William R; Gostjev, Feodor A

    2015-09-01

    This study provides a new assessment of Merton's anomie/strain theory and fills in several gaps in the literature. First, using the data from the sample of adolescents in an especially suitable and interesting setting, post-Soviet Ukraine, it investigates the applicability of the theory to this context and reveals that predictive powers of anomic strain may be influenced by larger sociocultural environments. Second, it evaluates the possibility of theoretical elaboration of Merton's theory through identifying contingencies such as external constraints on behavior and finds limited support for moderating effects of perceptions of risks of sanctioning and social bonds on anomic strain-delinquency relationships. Finally, it confirms that additional clarifications of the concept of anomic strain may be promising. © The Author(s) 2014.

  16. Atmospheric neutrino oscillation analysis with external constraints in Super-Kamiokande I-IV

    Science.gov (United States)

    Abe, K.; Bronner, C.; Haga, Y.; Hayato, Y.; Ikeda, M.; Iyogi, K.; Kameda, J.; Kato, Y.; Kishimoto, Y.; Marti, Ll.; Miura, M.; Moriyama, S.; Nakahata, M.; Nakajima, T.; Nakano, Y.; Nakayama, S.; Okajima, Y.; Orii, A.; Pronost, G.; Sekiya, H.; Shiozawa, M.; Sonoda, Y.; Takeda, A.; Takenaka, A.; Tanaka, H.; Tasaka, S.; Tomura, T.; Akutsu, R.; Irvine, T.; Kajita, T.; Kametani, I.; Kaneyuki, K.; Nishimura, Y.; Okumura, K.; Richard, E.; Tsui, K. M.; Labarga, L.; Fernandez, P.; Blaszczyk, F. d. M.; Gustafson, J.; Kachulis, C.; Kearns, E.; Raaf, J. L.; Stone, J. L.; Sulak, L. R.; Berkman, S.; Tobayama, S.; Goldhaber, M.; Carminati, G.; Elnimr, M.; Kropp, W. R.; Mine, S.; Locke, S.; Renshaw, A.; Smy, M. B.; Sobel, H. W.; Takhistov, V.; Weatherly, P.; Ganezer, K. S.; Hartfiel, B. L.; Hill, J.; Hong, N.; Kim, J. Y.; Lim, I. T.; Park, R. G.; Akiri, T.; Himmel, A.; Li, Z.; O'Sullivan, E.; Scholberg, K.; Walter, C. W.; Wongjirad, T.; Ishizuka, T.; Nakamura, T.; Jang, J. S.; Choi, K.; Learned, J. G.; Matsuno, S.; Smith, S. N.; Amey, J.; Litchfield, R. P.; Ma, W. Y.; Uchida, Y.; Wascko, M. O.; Cao, S.; Friend, M.; Hasegawa, T.; Ishida, T.; Ishii, T.; Kobayashi, T.; Nakadaira, T.; Nakamura, K.; Oyama, Y.; Sakashita, K.; Sekiguchi, T.; Tsukamoto, T.; Abe, KE.; Hasegawa, M.; Suzuki, A. T.; Takeuchi, Y.; Yano, T.; Hayashino, T.; Hirota, S.; Huang, K.; Ieki, K.; Jiang, M.; Kikawa, T.; Nakamura, KE.; Nakaya, T.; Patel, N. D.; Suzuki, K.; Takahashi, S.; Wendell, R. A.; Anthony, L. H. V.; McCauley, N.; Pritchard, A.; Fukuda, Y.; Itow, Y.; Mitsuka, G.; Murase, M.; Muto, F.; Suzuki, T.; Mijakowski, P.; Frankiewicz, K.; Hignight, J.; Imber, J.; Jung, C. K.; Li, X.; Palomino, J. L.; Santucci, G.; Vilela, C.; Wilking, M. J.; Yanagisawa, C.; Ito, S.; Fukuda, D.; Ishino, H.; Kayano, T.; Kibayashi, A.; Koshio, Y.; Mori, T.; Nagata, H.; Sakuda, M.; Xu, C.; Kuno, Y.; Wark, D.; Di Lodovico, F.; Richards, B.; Tacik, R.; Kim, S. B.; Cole, A.; Thompson, L.; Okazawa, H.; Choi, Y.; Ito, K.; Nishijima, K.; Koshiba, M.; Totsuka, Y.; Suda, Y.; Yokoyama, M.; Calland, R. G.; Hartz, M.; Martens, K.; Quilain, B.; Simpson, C.; Suzuki, Y.; Vagins, M. R.; Hamabe, D.; Kuze, M.; Yoshida, T.; Ishitsuka, M.; Martin, J. F.; Nantais, C. M.; de Perio, P.; Tanaka, H. A.; Konaka, A.; Chen, S.; Wan, L.; Zhang, Y.; Wilkes, R. J.; Minamino, A.; Super-Kamiokande Collaboration

    2018-04-01

    An analysis of atmospheric neutrino data from all four run periods of Super-Kamiokande optimized for sensitivity to the neutrino mass hierarchy is presented. Confidence intervals for Δ m322 , sin2θ23, sin2θ13 and δC P are presented for normal neutrino mass hierarchy and inverted neutrino mass hierarchy hypotheses, based on atmospheric neutrino data alone. Additional constraints from reactor data on θ13 and from published binned T2K data on muon neutrino disappearance and electron neutrino appearance are added to the atmospheric neutrino fit to give enhanced constraints on the above parameters. Over the range of parameters allowed at 90% confidence level, the normal mass hierarchy is favored by between 91.9% and 94.5% based on the combined Super-Kamiokande plus T2K result.

  17. Assessment of Pulmonary Toxicity Induced by Inhaled Toner with External Additives.

    Science.gov (United States)

    Tomonaga, Taisuke; Izumi, Hiroto; Yoshiura, Yukiko; Myojo, Toshihiko; Oyabu, Takako; Lee, Byeong-Woo; Okada, Takami; Li, Yunshan; Kawai, Kazuaki; Higashi, Toshiaki; Morimoto, Yasuo

    2017-01-01

    We investigated the harmful effects of exposure to a toner with external additives by a long-term inhalation study using rats, examining pulmonary inflammation, oxidative stress, and histopathological changes in the lung. Wistar rats were exposed to a well-dispersed toner (mean of MMAD: 2.1  μ m) at three mass concentrations of 1, 4, and 16 mg/m 3 for 22.5 months, and the rats were sacrificed after 6 months, 12 months, and 22.5 months of exposure. The low and medium concentrations did not induce statistically significant pulmonary inflammation, but the high concentration did, and, in addition, a histopathological examination showed fibrosis in the lung. Although lung tumor was observed in one sample of high exposure for 22.5 months, the cause was not statistically significant. On the other hand, a persistent increase in 8-OHdG was observed in the high exposure group, indicating that DNA damage by oxidative stress with persistent inflammation leads to the formation of tumorigenesis. The results of our studies show that toners with external additives lead to pulmonary inflammation, oxidative stress, and fibrosis only at lung burdens beyond overload. These data suggest that toners with external additives may have low toxicity in the lung.

  18. Assessment of Pulmonary Toxicity Induced by Inhaled Toner with External Additives

    Directory of Open Access Journals (Sweden)

    Taisuke Tomonaga

    2017-01-01

    Full Text Available We investigated the harmful effects of exposure to a toner with external additives by a long-term inhalation study using rats, examining pulmonary inflammation, oxidative stress, and histopathological changes in the lung. Wistar rats were exposed to a well-dispersed toner (mean of MMAD: 2.1 μm at three mass concentrations of 1, 4, and 16 mg/m3 for 22.5 months, and the rats were sacrificed after 6 months, 12 months, and 22.5 months of exposure. The low and medium concentrations did not induce statistically significant pulmonary inflammation, but the high concentration did, and, in addition, a histopathological examination showed fibrosis in the lung. Although lung tumor was observed in one sample of high exposure for 22.5 months, the cause was not statistically significant. On the other hand, a persistent increase in 8-OHdG was observed in the high exposure group, indicating that DNA damage by oxidative stress with persistent inflammation leads to the formation of tumorigenesis. The results of our studies show that toners with external additives lead to pulmonary inflammation, oxidative stress, and fibrosis only at lung burdens beyond overload. These data suggest that toners with external additives may have low toxicity in the lung.

  19. Improved Coarray Interpolation Algorithms with Additional Orthogonal Constraint for Cyclostationary Signals

    Directory of Open Access Journals (Sweden)

    Jinyang Song

    2018-01-01

    Full Text Available Many modulated signals exhibit a cyclostationarity property, which can be exploited in direction-of-arrival (DOA estimation to effectively eliminate interference and noise. In this paper, our aim is to integrate the cyclostationarity with the spatial domain and enable the algorithm to estimate more sources than sensors. However, DOA estimation with a sparse array is performed in the coarray domain and the holes within the coarray limit the usage of the complete coarray information. In order to use the complete coarray information to increase the degrees-of-freedom (DOFs, sparsity-aware-based methods and the difference coarray interpolation methods have been proposed. In this paper, the coarray interpolation technique is further explored with cyclostationary signals. Besides the difference coarray model and its corresponding Toeplitz completion formulation, we build up a sum coarray model and formulate a Hankel completion problem. In order to further improve the performance of the structured matrix completion, we define the spatial spectrum sampling operations and the derivative (conjugate correlation subspaces, which can be exploited to construct orthogonal constraints for the autocorrelation vectors in the coarray interpolation problem. Prior knowledge of the source interval can also be incorporated into the problem. Simulation results demonstrate that the additional constraints contribute to a remarkable performance improvement.

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

    DEFF Research Database (Denmark)

    Schmidt, Johannes Dragsbæk

    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 remarks....

  1. A novel gripper design for multi hand tools grasping under tight clearance constraints and external torque effect

    KAUST Repository

    Shaqura, Mohammad

    2017-08-29

    A robotic multi tool gripper design and implementation is presented in this paper. The proposed design targets applications where an actuation task is performed using a wide selection of standard hand tools. The manipulation motion is assumed to be rotational which requires a firm grip to account for external torque on the grasped tool. The setup is assumed to be a conventional workshop panel with hand tools being hanged close to each other, which constraints lateral clearance around the target, and near the wall of the panel, which constraints the depth clearance. Off the shelf grippers are mostly heavy and bulky which make them unsuitable for these requirements. Moreover, they are not optimized in terms of power consumption, simplicity and compactness. These generic grippers are mostly designed for pick and place tasks where no external torques other than those caused by the object weight affects the gripper. The design challenge involves building a gripper that is capable of operating in limited clearance space, firmly grip a variety of standard hand tools with different sizes and shapes. The proposed design is optimized for these objectives and offers a low cost and power consumption solution. The design has been validated in lab and outdoor experiments and has been deployed in real operating platform used in an international robotics competition.

  2. Incorporating shape constraints in generalized additive modelling of the height-diameter relationship for Norway spruce

    Directory of Open Access Journals (Sweden)

    Natalya Pya

    2016-02-01

    Full Text Available Background: Measurements of tree heights and diameters are essential in forest assessment and modelling. Tree heights are used for estimating timber volume, site index and other important variables related to forest growth and yield, succession and carbon budget models. However, the diameter at breast height (dbh can be more accurately obtained and at lower cost, than total tree height. Hence, generalized height-diameter (h-d models that predict tree height from dbh, age and other covariates are needed. For a more flexible but biologically plausible estimation of covariate effects we use shape constrained generalized additive models as an extension of existing h-d model approaches. We use causal site parameters such as index of aridity to enhance the generality and causality of the models and to enable predictions under projected changeable climatic conditions. Methods: We develop unconstrained generalized additive models (GAM and shape constrained generalized additive models (SCAM for investigating the possible effects of tree-specific parameters such as tree age, relative diameter at breast height, and site-specific parameters such as index of aridity and sum of daily mean temperature during vegetation period, on the h-d relationship of forests in Lower Saxony, Germany. Results: Some of the derived effects, e.g. effects of age, index of aridity and sum of daily mean temperature have significantly non-linear pattern. The need for using SCAM results from the fact that some of the model effects show partially implausible patterns especially at the boundaries of data ranges. The derived model predicts monotonically increasing levels of tree height with increasing age and temperature sum and decreasing aridity and social rank of a tree within a stand. The definition of constraints leads only to marginal or minor decline in the model statistics like AIC. An observed structured spatial trend in tree height is modelled via 2-dimensional surface

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

    DEFF Research Database (Denmark)

    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 n......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 conclusive evidence in the literature to decide what determines what. There are important dynamics and interplays across the thin line between the domestic and international sphere especially in terms of understanding the reciprocal challenges related to how the factors of culture and ethnicity relate...... with the legitimacy of the state. The aim of the paper serves four purposes. To unpack and give a critical overview of the debates concerned with the internal and external aspects of India’s foreign policy; situate the literature dealing more specifically with domestic issues related to culture and ethnicity...

  4. Urethral dosimetry constraints in 125I permanent prostate brachytherapy used as boost to external radiotherapy

    International Nuclear Information System (INIS)

    Lliso, F.; Perez-Calatayud, J.; Carmona, V.; Guirado, D.; Munoz, M.; Richart, J.; Ballester, F.; Granero, D.; Rodriguez, S.; Tormo, A.; Santos, M.

    2010-01-01

    With 125I monotherapy in permanent brachytherapy implants, the recommendation is to deliver to the urethra less than 150% of the prescribed dose, 145 Gy, that is a limit of 217.5 Gy. However, there are not recommendations in the case of the brachytherapy boost. At our hospitals, permanent brachytherapy implants are used as a 108 Gy boost in intermediate risk patients with prostate carcinoma, which have undergone an external beam radiotherapy course ranging between 45 and 50.4 Gy. The purpose of this work is to present a simple radiobiologically-based analysis performed in order to obtain the urethral dose limit in permanent prostate brachytherapy boost. The linear-quadratic model has been used to determine the biologically effective dose, analysing the results for different dose/fraction, t1/2 and a/b values. Assuming 46 Gy delivered by external beam radiotherapy, it is found that a limit value of 145 Gy, corresponding to the isodose level of 135% of the prescribed dose, is adequate. The results for a ten patients sample are shown in order to illustrate the values that are obtained in clinical practice. In conclusion, we present the method employed to find the urethral dose limit in the case of the combination of external beam radiotherapy and permanent 125I seeds brachytherapy boost implants (Author).

  5. L0 norm constraint based external control source allocation for the minimum cost control of directed networks.

    Science.gov (United States)

    Deng, Lei; Li, Guoqi; Pei, Jing; Huang, Jiangshuai

    2018-03-13

    Locating a pre-given number of key nodes that are connected to external control sources so as to minimize the cost of controlling a directed network ẋ(t)=Ax(t)+Bu(t), known as the minimum cost control problem, is of critical importance. Considering a network consisting of N nodes with M external control sources, the state of art techniques employ iterative searching to determine the input matrix B that characterizes how nodes are connected to external control sources, in a matrix space R N×M . The nodes having M largest values of a defined importance index are selected as key nodes. However, such techniques may suffer from large performance penalty in some networks due to the diversity of real-life networks. To address this outstanding issue, we propose an iterative method, termed "L 0 -norm constraint based projected gradient method" (LPGM). We probabilistically search the input matrix in each iteration by restricting its L 0 norm as a fixed value M, which implies that each control source is always only connected to a single key node during the whole searching process. Simulation results show that the solution always efficiently approaches a suboptimal key node set in a few iterations. These results provide a new point of view regarding the key nodes selection in the minimum cost control of directed networks. Copyright © 2018. Published by Elsevier Ltd.

  6. Modeling additional solar constraints on a human being inside a room

    Energy Technology Data Exchange (ETDEWEB)

    Thellier, Francoise; Monchoux, Francoise; Bonnis-Sassi, Michel; Lartigue, Berengere [Laboratoire Physique de l' Homme Appliquee a Son Environnement (PHASE), Universite Paul Sabatier, 118, route de Narbonne, F-31062 Toulouse Cedex 9 (France)

    2008-04-15

    Sun fluxes induce additional heterogeneous thermal constraints in buildings and may also lead to discomfort for the inhabitant. To calculate the local thermal sensation of a human being totally or partially situated in the sunlight, the solar radiation inside a room and its detailed distribution on parts of the human body are modeled. The present study focuses on the solar gains part of a complete modeling tool simulating an occupied building. The irradiated areas are calculated with a ray tracing method taking shadow into account. Solar fluxes are computed. Fluxes can be absorbed by each surface or reflected. The reflected fluxes are then absorbed at the next impact. A multi-node thermoregulation model (MARCL) represents the thermal behavior of the human body and all its heat exchanges with the environment. The thermal transient simulation of the whole occupied building is performed in TRNSYS simulation software. In the case presented here, the results show that, when a person is inside the building, the skin and clothing temperatures of the irradiated segments increase more or less depending on the segments but the global thermal equilibrium of the body is maintained thanks to strong physiological reactions. (author)

  7. Short-wavelength Contractional Structures in Venusian Fold Belts: Additional Constraints From New Models

    Science.gov (United States)

    Ghent, R.; Phillips, R.; Hansen, V.; Nunes, D.

    2002-12-01

    We have previously reported on the development of very short-wavelength (30 km [1, 2]. We simulated the initiation and growth of VST using finite-element models with uniform composition and elasto-visco-plastic rheology undergoing simultaneous cooling and shortening. The models were constrained by Magellan SAR imagery and motivated by the current plume hypothesis for crustal plateau origin [3, 4]. We determined that VST developed only in models with surface temperatures near 1000 K and elevated thermal gradients derived from a halfspace cooling model with initial uniform temperatures of 1200-1400 K. Model rheological profiles indicated a truly viscoplastic character, in which both creep and plastic mechanisms were significant at shallow depths. The resulting topography showed both very short-wavelength components and slightly longer-wavelength, low amplitude folds, as is common in Venusian crustal plateau fold belts. New simulations with greater spatial extent and higher mesh resolution allow further exploration of the interplay between viscous and plastic processes during VST development. Wider models allow more detailed investigation of viscous folding on the 1-4 km scale. We also employ temperature-dependent thermal conductivity [5] to better represent the thermal behavior of the model crust. The additional insight and expanded parameter space provided by these new models allow us to place improved constraints on the early thermal and mechanical evolution of crustal plateaus. [1] Ghent, R.R., R.J. Phillips, V.L. Hansen, and D.C. Nunes, Eos Trans. AGU, 83(19), Spring Meet. Suppl., Abstract P21A-05, 2002. [2] Ghent, R.R., R.J. Phillips, and V.L. Hansen, 2001, Eos Trans. AGU, 82(47), Spring Meet. Suppl., Abstract T41B-0865, 2001. [3] Hansen, V.L. and J.J. Willis, Icarus, 132, 321-343, 1998. [4] Phillips, R.J. and V.L. Hansen, Science, 279, p1492, 1998. [5] Hofmeister, A, Science, 283, p1699, 1999.

  8. Tuning the carbon nanotube photoluminescence enhancement at addition of cysteine through the change of external conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kurnosov, N.V.; Karachevtsev, M.V.; Leontiev, V.S.; Karachevtsev, V.A., E-mail: karachevtsev@ilt.kharkov.ua

    2017-01-15

    The enhancement of the photoluminescence (PL) from the semiconducting single-walled carbon nanotubes suspended with single-stranded DNA (ssDNA) in water observed after amino acids doping is the largest at cysteine addition. The PL intensity increased through the passivation of p-defects on the carbon nanotube sidewall by the cysteine molecules due to thiol group. The effect of several external factors on the cysteine-induced enhancement of PL from carbon nanotubes covered with ssDNA was studied: UV irradiation, tip or bath sonication treatment of the suspension, the ionic strength and pH of aqueous suspension. It turned out that all these factors have an essential influence on the dependence of the PL enhancement on the cysteine concentration through inducing of additional defects on nanotube as well as a change of the nanotube surface coverage with polymer. The obtained experimental results demonstrated that PL from carbon nanotubes can be exploited successfully for the monitoring of cysteine concentration in aqueous solution. - Highlights: • Cysteine doping enhances carbon nanotube emission more than other amino acids do. • SWNT emission dependence on cysteine concentration is tuned by UV irradiation and pH. • Type of sonication treatment influences SWNT PL dependence on cysteine concentration. • Polymer coverage and defectiveness of nanotubes effect on nanotube emission. • Graphic abstract.

  9. Bringing organic carbon isotopes and phytoliths to the table as additional constraints on paleoelevation

    Science.gov (United States)

    Sheldon, N. D.; Cotton, J. M.; Hren, M. T.; Hyland, E. G.; Smith, S. Y.; Strömberg, C. A. E.

    2015-12-01

    A commonly used tool in paleotectonic and paleoaltimetry studies is the oxygen isotopic composition of authigenic carbonates formed that formed in lakes or soils, with both spatial (e.g., shoreline to mountain top) or temporally resolved records potentially providing constraints. However, in many cases there is a substantial spread in the oxygen isotope data for a given time period, often to the point of allowing for essentially any interpretation of the data depending upon how they have been used by the investigator. One potential way of distinguishing between different potential paleotectonic or paleoaltimetric interpretations is to use carbon isotope and plant microfossil (phytolith) analyses from the same paleosols to screen the oxygen isotope data by looking for evidence of evaporative enrichment. For example, if both inorganic (carbonate) and organic carbon isotopes are measured from the same paleosol, then in it possible to determine if the two isotope record equilibrium conditions or if they record disequilibrium driven by kinetic effects. In the former case, the oxygen isotope results can be considered reliable whereas in the latter case, the oxygen isotope results can be considered unreliable and could be culled from the interpretation. Similarly, because the distribution of C4 plants varies as a function of temperature and elevation, the presence/absence or abundance of C4 plant phytoliths, or of carbon isotope compositions that require a component of C4 vegetation can also be used to constrain paleoelevation by providing a maximum elevation constraint. Worked examples will include the late Miocene-Pliocene of Catamarca, Argentina, where phytoliths and organic carbon isotopes provide a maximum elevation constraint and can be used to demonstrate that oxygen isotopes do not provide a locally useful constraint on paleoelevation, and Eocene-Miocene of southwestern Montana where organic matter and phytoliths can be used to select between different potential

  10. Personality and externalizing behavior in the transition to young adulthood : The additive value of personality facets

    NARCIS (Netherlands)

    Klimstra, Theo A.; Luyckx, Koen; Hale, William W.; Goossens, Luc

    2014-01-01

    Purpose: The directionality of effects in the associations between personality and externalizing behavior (i.e., delinquency, soft drugs use, and alcohol abuse) is unclear. Moreover, previous studies only examined personality trait domains when examining these associations, whereas personality

  11. Personality and externalizing behavior in the transition to young adulthood : The additive value of personality facets

    NARCIS (Netherlands)

    Klimstra, T.A.; Luyckx, K.; Hale, W.W.; Goossens, L.

    2014-01-01

    Purpose The directionality of effects in the associations between personality and externalizing behavior (i.e., delinquency, soft drugs use, and alcohol abuse) is unclear. Moreover, previous studies only examined personality trait domains when examining these associations, whereas personality facets

  12. Personality and externalizing behavior in the transition to young adulthood: the additive value of personality facets.

    Science.gov (United States)

    Klimstra, Theo A; Luyckx, Koen; Hale Iii, William W; Goossens, Luc

    2014-08-01

    The directionality of effects in the associations between personality and externalizing behavior (i.e., delinquency, soft drugs use, and alcohol abuse) is unclear. Moreover, previous studies only examined personality trait domains when examining these associations, whereas personality facets underlying these broad domains provide more specificity. To address these limitations, the present study examined the directionality of effects between externalizing behavior and personality while employing a facet-level approach to personality. Cross-lagged panel models were employed to four annual measurement waves of longitudinal data on 485 Belgian-Caucasian late adolescents (87.4 % female; M age = 18.63 years, SD = 0.61). Participants filled out the NEO-FFI as a measure of personality, the Deviant Behavior Scale as a measure of delinquency, and single items for soft drugs use and alcohol abuse on all four measurement occasions. The incremental value of personality facets over broad trait domains was demonstrated, as it was often the case that only some, but not all, facets underlying a specific trait domain were significantly associated with specific externalizing behaviors. Furthermore, linkages between personality and externalizing behavior were shown to be complex. Depending on the personality trait domain or facet and the specific behavior under investigation, the directionality of effects may differ. To capture the full complexity of the linkages between personality and externalizing behavior, a facet approach to personality is recommended. This information is potentially important for clinicians, as it indicates which specific aspects of a broad trait domain affect, and are affected by, specific externalizing behaviors.

  13. ExSTA: External Standard Addition Method for Accurate High-Throughput Quantitation in Targeted Proteomics Experiments.

    Science.gov (United States)

    Mohammed, Yassene; Pan, Jingxi; Zhang, Suping; Han, Jun; Borchers, Christoph H

    2018-03-01

    Targeted proteomics using MRM with stable-isotope-labeled internal-standard (SIS) peptides is the current method of choice for protein quantitation in complex biological matrices. Better quantitation can be achieved with the internal standard-addition method, where successive increments of synthesized natural form (NAT) of the endogenous analyte are added to each sample, a response curve is generated, and the endogenous concentration is determined at the x-intercept. Internal NAT-addition, however, requires multiple analyses of each sample, resulting in increased sample consumption and analysis time. To compare the following three methods, an MRM assay for 34 high-to-moderate abundance human plasma proteins is used: classical internal SIS-addition, internal NAT-addition, and external NAT-addition-generated in buffer using NAT and SIS peptides. Using endogenous-free chicken plasma, the accuracy is also evaluated. The internal NAT-addition outperforms the other two in precision and accuracy. However, the curves derived by internal vs. external NAT-addition differ by only ≈3.8% in slope, providing comparable accuracies and precision with good CV values. While the internal NAT-addition method may be "ideal", this new external NAT-addition can be used to determine the concentration of high-to-moderate abundance endogenous plasma proteins, providing a robust and cost-effective alternative for clinical analyses or other high-throughput applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. On the addition of heat to solar pond from external sources

    NARCIS (Netherlands)

    Ganguly, S.; Jain, Ravi; Date, Abhijit; Akbarzadeh, Aliakbar

    2017-01-01

    This brief note addresses the method of adding heat to a solar pond from an external source which is used to enhance the performance of a solar pond. Heat energy collected by Evacuated Tube Solar Collectors (ETSC) is transferred by circulating fluid from the Lower Convective Zone (LCZ) of a solar

  15. Coherent addition of high power broad-area laser diodes with a compact VBG V-shaped external Talbot cavity

    Science.gov (United States)

    Liu, Bo; Braiman, Yehuda

    2018-05-01

    We introduced a compact V-shaped external Talbot cavity for phase locking of high power broad-area laser diodes. The length of compact cavity is ∼25 mm. Near diffraction-limit coherent addition of 10 broad-area laser diodes indicated that high quality phase locking was achieved. We measured the near-field emission mode of each individual broad-area laser diode with different feedback, such as a volume Bragg grating and a high reflection mirror. We found out that the best result of phase locking broad-area laser diodes was achieved by the compact V-shaped external Talbot cavity with volume Bragg grating feedback.

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

    International Nuclear Information System (INIS)

    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)

  17. Replacing the Concept of Externalities to Analyze Constraints on Global Economic Growth and Move Toward a New Economic Paradigm

    Directory of Open Access Journals (Sweden)

    Jim Lunday

    2014-10-01

    Full Text Available The prevailing economic paradigm has fallen short as a guide to policy making in this era of global economic crises. Numerous efforts are underway to revise it or replace it with a science of society that integrates intellectual disciplines. This paper makes a contribution to those efforts by arguing that the economic concept of externalities is no longer viable and that replacing it with the concept of an inclusive world economy provides new explanatory potential. The concept of externalities divides the world hierarchically, with the internal dominant and the external subordinate. In this way it gives any group of people the scientific legitimacy to conquer, manage and use other peoples and the natural world (the external instrumentally; by extension, it drives the creation of ever newer technologies to do so. The concept fit the economic growth experiences of the emerging capitalist nations in the centuries prior to the 20th fairly well. Now that we live in a world in which all peoples, all economic activities, and all of the earth are tied together into a global economy that is no longer the case. The concept of an inclusive world economy fits our contemporary experiences better, aligns well with an integrated science approach, and provides new insights into prospects for economic growth.

  18. A taxa de câmbio real e a restrição externa: uma proposta de releitura com elasticidades endógenas Real exchange rate and external constraint

    Directory of Open Access Journals (Sweden)

    Marcos Adolfo Ribeiro Ferrari

    2013-03-01

    Full Text Available This paper investigates a topic of the agenda about growth models, emphasizing the elaboration of an external constrained model with endogenous elasticity, with an emphasis on real exchange rate level as main tool for the economic development. The model is anchored in Kaldor, Thirlwall and Barbosa Filho's models and it will demonstrate that external constraint changes in the course of time.

  19. When do anterior external or internal fixators provide additional stability in an unstable (Tile C) pelvic fracture? A biomechanical study.

    Science.gov (United States)

    Mcdonald, E; Theologis, A A; Horst, P; Kandemir, U; Pekmezci, M

    2015-12-01

    This study aimed at evaluating the additional stability that is provided by anterior external and internal fixators in an unstable pelvic fracture model (OTA 61-C). An unstable pelvic fracture (OTA 61-C) was created in 27 synthetic pelves by making a 5-mm gap through the sacral foramina (posterior injury) and an ipsilateral pubic rami fracture (anterior injury). The posterior injury was fixed with either a single iliosacral (IS) screw, a single trans-iliac, trans-sacral (TS) screw, or two iliosacral screws (S1S2). Two anterior fixation techniques were utilized: external fixation (Ex-Fix) and supra-acetabular external fixation and internal fixation (In-Fix); supra-acetabular pedicle screws connected with a single subcutaneous spinal rod. The specimens were tested using a nondestructive single-leg stance model. Peak-to-peak (P2P) displacement and rotation and conditioning displacement (CD) were calculated. The Ex-Fix group failed in 83.3 % of specimens with concomitant single-level posterior fixation (Total: 15/18-7 of 9 IS fixation, 8 of 9 TS fixation), and 0 % (0/9) of specimens with concomitant two-level (S1S2) posterior fixation. All specimens with the In-Fix survived testing except for two specimens treated with In-Fix combined with IS fixation. Trans-sacral fixation had higher pubic rotation and greater sacral and pubic displacement than S1S2 (p pelvic fracture (OTA 61-C), anterior fixation with an In-Fix was biomechanically superior to an anterior Ex-Fix in the setting of single-level posterior fixation. There was no biomechanical difference between the In-Fix and Ex-Fix when each was combined with two levels of posterior sacral fixation.

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

    DEFF Research Database (Denmark)

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

    Science.gov (United States)

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

    2015-04-01

    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 {Δ }{{χ }2}\\lt 80 for seven out of eight analyzed events. For MOA-2009-BLG-319, the improvement is relatively big with {Δ }{{χ }2}∼ 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 space. For this purpose, we construct exclusion diagrams showing the confidence levels excluding the existence of an additional planet as a function of its separation and mass ratio. We also present the exclusion ranges of additional planets with 90% confidence level for Jupiter-, Saturn-, and Uranus-mass planets.

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

    DEFF Research Database (Denmark)

    Pedersen, Brian; Rein, Tobias; Søtofte, Inger

    2003-01-01

    Some new results on asymmetric synthesis via the addition of a-metalated methyl tolyl sulfoxides to imines are presented. Good diastereoselectivity (up to > 98% d.e. for product 3g) can be obtained under conditions of kinetic control (short reaction time, low temperature). The transition state (a......) to (> 99 : 1) by use of a readily available C2-symmetric bis(sulfonamide) ligand....

  3. Effect of external phosphate addition on solid-phase iron distribution and iron accumulation in Mangrove Kandelia obovata (S. L.).

    Science.gov (United States)

    Du, Jingna; Liu, Jingchun; Lu, Haoliang; Hansell, Dennis; Zhang, Qiong; Wang, Wenyun; Yan, Chongling

    2015-09-01

    In this study, a pot experiment was conducted to evaluate the effect of phosphate (PO4 (3-)) addition on iron (Fe) cycling in mangrove ecosystem. Kandelia obovata (S. L.), one of the dominant mangrove species in the southeast of China, was cultivated in rhizoboxes under three different levels of P concentrations. Results showed the solid-phase Fe distribution and Fe(II)/Fe(III) values in both the root zone (rhizosphere) and bulk soil (non-rhizosphere) were comparable among all P levels (p > 0.05); P addition significantly decreased the pore water Fe content both in the rhizosphere and non-rhizosphere zone (p mangrove plants; more reactive iron, higher abundance of root Fe-reducing bacteria (FeRB) and Fe-oxidizing bacteria (FeOB), and together with higher amount of K. obovata (S. L.) root organic acids exudation result in a rapid Fe cycling in rhizosphere, which contribute to comparable solid-phase iron distribution among different P levels.

  4. The effects of nano- and micro-particle additives on the durability and mechanical properties of mortars exposed to internal and external sulfate attacks

    Directory of Open Access Journals (Sweden)

    Hasan Şahan Arel

    Full Text Available In this study, the effects of micro-silica (MS, nano-silica (NS, class C fly ash (FA, and metakaolin (MK on the durability and mechanical properties of mortars exposed to internal and external sulfate attacks were investigated. For that purpose, mortars were produced from 3 different sands with different ratios of sulfate ions to generate conditions for an internal sulfate attack. Standard curing procedures were applied to all mortar samples for 23 weeks. Furthermore, mortar samples prepared from Sand A, which had the lowest sulfate content, were kept in sodium sulfate and magnesium sulfate solutions to produce an external sulfate attack. When all test results were evaluated together, the most significant contribution to durability and strength among the admixtures was observed to be from NS, which demonstrated an average improvement of 2–10% over MS, which had the second most significant contribution for mortar samples exposed to the most severe internal and external sulfate attacks. When all mixing ratios and tests were considered, the least significant contribution to durability and strength was determined to be from metakaolin. Additionally, when the test data for all days were compared, magnesium sulfate was found to be approximately 1–10% more destructive in comparison to sodium sulfate. Keywords: Nano-silica, Micro-silica, Durability, Mechanical properties, Mortar, Sulfate attack

  5. Additive genetic variation in resistance traits of an exotic pine species: little evidence for constraints on evolution of resistance against native herbivores.

    Science.gov (United States)

    Moreira, X; Zas, R; Sampedro, L

    2013-05-01

    The apparent failure of invasions by alien pines in Europe has been explained by the co-occurrence of native pine congeners supporting herbivores that might easily recognize the new plants as hosts. Previous studies have reported that exotic pines show reduced tolerance and capacity to induce resistance to those native herbivores. We hypothesize that limited genetic variation in resistance to native herbivores and the existence of evolutionary trade-offs between growth and resistance could represent additional potential constraints on the evolution of invasiveness of exotic pines outside their natural range. In this paper, we examined genetic variation for constitutive and induced chemical defences (measured as non-volatile resin in the stem and total phenolics in the needles) and resistance to two major native generalist herbivores of pines in cafeteria bioassays (the phloem-feeder Hylobius abietis and the defoliator Thaumetopoea pityocampa) using half-sib families drawn from a sample of the population of Pinus radiata introduced to Spain in the mid-19th century. We found (i) significant genetic variation, with moderate-to-high narrow-sense heritabilities for both the production of constitutive non-volatile resin and induced total phenolics, and for constitutive resistance against T. pityocampa in bioassays, (ii) no evolutionary trade-offs between plant resistance and growth traits or between the production of different quantitative chemical defences and (iii) a positive genetic correlation between constitutive resistance to the two studied herbivores. Overall, results of our study indicate that the exotic pine P. radiata has limited genetic constraints on the evolution of resistance against herbivores in its introduced range, suggesting that, at least in terms of interactions with these enemies, this pine species has potential to become invasive in the future.

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

    Directory of Open Access Journals (Sweden)

    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

  7. Tectonic constraints on the development and individualization of the intermontane Ronda basin (external Betics, southern Spain): a structural and geomorphologic approach.

    Science.gov (United States)

    Jiménez-Bonilla, Alejandro; Balanyá, Juan Carlos; Expósito, Inmaculada; Díaz-Azpiroz, Manuel; Barcos, Leticia

    2014-05-01

    As a result of progressive shortening and orogenic wedge thickening, marine foreland basins tend to emerge and divide. We have analyzed possible recent tectonic activity within the late evolution stage of the Ronda basin, an intermontane basin located in the external wedge of the Gibraltar Arc, formerly connected with the Betic foreland basin and infilled by marine Upper-Miocene sediments. We analyze (1) the structures responsible for the basinward relief drop along the arc strike and the different topography of their boundaries; (2) qualitative and quantitative geomorphologic indices to asses which structures could present recent activity; and 3) the structures causing the division of the former Betic foreland basin and the isolation of the Ronda basin. Within the deformational history of the Ronda basin, late structures that control high topographic gradients and generate remarkable fault scarps group into three main types: (a) Extensional structures represented by NW-SE striking normal faults, clustered close to the current SW and NE boundaries of the basin. They usually dip towards the basin and their vertical displacement is maximum up to 1,5 km. These structures partially affect the basal unconformity of the Upper Miocene basin infill and are scarcely developed inside the basin infill. (b) Shortening structures developed both in the basin infill and in the outcropping basement near the Northeastern and Southwestern basin boundaries. They are represented by NE-SW directed plurikilometric box-folds and reverse faults, responsible for the alternation of sierras (altitudes 1000-1500 m) and valleys. (c) Strike-slip dominated structural associations where WSW-ENE lateral faults combined with folds and normal and reverse faults defined a NE-SW directed deformation band constituting the NW basin boundary. This band includes some sierras up to 1.100 m. Regarding the relief of the Ronda basin area, the abrupt slopes of the outcropping basement (heights between 500

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

    International Nuclear Information System (INIS)

    Schiffmann, Jonas; Tennstedt, Pierre; Beyer, Burkhard; Boehm, Katharina; Tilki, Derya; Salomon, Georg; Graefen, Markus; Lesmana, Hans; Platz, Volker; Petersen, Cordula; Kruell, Andreas; Schwarz, Rudolf

    2015-01-01

    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.) [de

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Constraint Differentiation

    DEFF Research Database (Denmark)

    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...... results show that constraint differentiation substantially reduces search and considerably improves the performance of OFMC, enabling its application to a wider class of problems....

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Regional Externalities

    NARCIS (Netherlands)

    Heijman, W.J.M.

    2007-01-01

    The book offers practical and theoretical insights in regional externalities. Regional externalities are a specific subset of externalities that can be defined as externalities where space plays a dominant role. This class of externalities can be divided into three categories: (1) externalities

  13. Conception d'un cours de luxembourgeois en ligne : prise en compte de contraintes externes dans les choix méthodologiques et didactiques Design of an online Luxemburgish course : taking into account external constraints for methodological and didactic choices

    Directory of Open Access Journals (Sweden)

    Denis Zampuniéris

    2007-06-01

    Full Text Available À travers le projet Quattropole : e-learning pour l'apprentissage du luxembourgeois, nous aborderons la conception et la réalisation d'un cours de luxembourgeois en ligne. Cet article relatera les difficultés liées à la mise en place d'un tel dispositif pour un public d'adultes francophones frontaliers. En analysant les choix méthodologiques et didactiques en rapport avec les contraintes externes, cet article présentera le retour d'expérience sur la base des réponses des apprenants au formulaire de satisfaction mis à leur disposition.Through the presentation of the project Quattropole: e-learning for the Luxemburgish language, this paper will describe the design and the production of a web-based Luxemburgish course. It will discuss some issues relating to the implementation of such a language learning environment targeting frontier French-speaking adults. Following the analysis of methodological and didactic choices resulting from external constraints, this paper will also present the results of an online satisfaction questionnaire made available to learners.

  14. Incorporation of additional radionuclides and the external exposure pathway into the BECAMP [Basic Environmental Compliance and Monitoring Program] radiological assessment model

    International Nuclear Information System (INIS)

    Ng, Yook C.; Rodean, H.C.; Anspaugh, L.R.

    1988-11-01

    The Nevada Applied Ecology Group (NAEG) Model of transport and dose for transuranic radionuclides was modified and expanded for the analysis of radionuclides other than pure alpha-emitters. Doses from internal and external exposures were estimated for the inventories and soil distributions of the individual radionuclides quantified in Areas 2 and 4 of the Nevada Test Site (NTS). We found that the dose equivalents via inhalation to liver, lungs, bone marrow, and bone surface from the plutonium isotopes and 241 Am, those via ingestion to bone marrow and bone surfaces from 90 Sr, and those via ingestion to all the target organs from 137 Cs were the highest from internal exposures. The effective dose equivalents from 137 Cs, 152 Eu, and 154 Eu were the highest from the external exposures. The 60 Co, 152 Eu, 154 Eu, and 155 Eu dose estimates for external exposures greatly exceeded those for internal exposures. The 60 Co, 90 Sr, and 137 Cs dose equivalents from internal exposures were underestimated due to the adoption of some of the foodchain parameter values originally selected for 239 Pu. Nonetheless, the ingestion pathway contributed significantly to the dose estimates for 90 Sr and 137 Cs, but contributed very much less than external exposures to the dose estimates for 60 Co. Therefore, the use of more appropriate values would not alter the identification of important radionuclides, pathways, target organs, and exposure modes in this analysis. 19 refs., 13 figs., 12 tabs

  15. Momentum constraint relaxation

    International Nuclear Information System (INIS)

    Marronetti, Pedro

    2006-01-01

    Full relativistic simulations in three dimensions invariably develop runaway modes that grow exponentially and are accompanied by violations of the Hamiltonian and momentum constraints. Recently, we introduced a numerical method (Hamiltonian relaxation) that greatly reduces the Hamiltonian constraint violation and helps improve the quality of the numerical model. We present here a method that controls the violation of the momentum constraint. The method is based on the addition of a longitudinal component to the traceless extrinsic curvature A ij -tilde, generated by a vector potential w i , as outlined by York. The components of w i are relaxed to solve approximately the momentum constraint equations, slowly pushing the evolution towards the space of solutions of the constraint equations. We test this method with simulations of binary neutron stars in circular orbits and show that it effectively controls the growth of the aforementioned violations. We also show that a full numerical enforcement of the constraints, as opposed to the gentle correction of the momentum relaxation scheme, results in the development of instabilities that stop the runs shortly

  16. The constraints

    International Nuclear Information System (INIS)

    Jones, P.M.S.

    1987-01-01

    There are considerable incentives for the use of nuclear in preference to other sources for base load electricity generation in most of the developed world. These are economic, strategic, environmental and climatic. However, there are two potential constraints which could hinder the development of nuclear power to its full economic potential. These are public opinion and financial regulations which distort the nuclear economic advantage. The concerns of the anti-nuclear lobby are over safety, (especially following the Chernobyl accident), the management of radioactive waste, the potential effects of large scale exposure of the population to radiation and weapons proliferation. These are discussed. The financial constraint is over two factors, the availability of funds and the perception of cost, both of which are discussed. (U.K.)

  17. Constraint Programming for Context Comprehension

    DEFF Research Database (Denmark)

    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...... of knowledge. The language of Constraint Handling Rules, CHR, is suggested for defining constraint solvers that reflect “world knowledge” for the given domain, and driver algorithms may be ex- pressed in Prolog or additional rules of CHR. It is argued that this way of doing context comprehension is an instance...

  18. Regulating multiple externalities

    DEFF Research Database (Denmark)

    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...... instruments. However, solving the open-access externality problem also affects CO2 emissions. By using a bio-economic model covering Iceland, Norway, Denmark, Sweden, and the Faroe Islands, it is shown that regulations of the open-access externality problem have a large effect on both economic performance...... and CO2 emissions, while an additional CO2 regulation only has minor effects. The second-best solution achieved by only regulating open access reduces emissions by approximately 50% compared to current fisheries, with the exception of Iceland, which already has a well-developed fisheries management...

  19. Searching for genomic constraints

    International Nuclear Information System (INIS)

    Lio', P.; Ruffo, S.

    1998-01-01

    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

  20. Externality or sustainability economics?

    International Nuclear Information System (INIS)

    Bergh, Jeroen C.J.M. van den

    2010-01-01

    In an effort to develop 'sustainability economics' Baumgaertner and Quaas (2010) neglect the central concept of environmental economics-'environmental externality'. This note proposes a possible connection between the concepts of environmental externality and sustainability. In addition, attention is asked for other aspects of 'sustainability economics', namely the distinction weak/strong sustainability, spatial sustainability and sustainable trade, distinctive sustainability policy, and the ideas of early 'sustainability economists'. I argue that both sustainability and externalities reflect a systems perspective and propose that effective sustainability solutions require that more attention is given to system feedbacks, notably other-regarding preferences and social interactions, and energy and environmental rebound. The case of climate change and policy is used to illustrate particular statements. As a conclusion, a list of 20 insights and suggestions for research is offered. (author)

  1. Efficient Searching with Linear Constraints

    DEFF Research Database (Denmark)

    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...

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

    International Nuclear Information System (INIS)

    Holland, M.; Berry, J.

    1995-01-01

    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

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

    International Nuclear Information System (INIS)

    Holland, M.; Berry, J.

    1994-01-01

    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

  4. Relationship between protein structure and geometrical constraints

    DEFF Research Database (Denmark)

    Lund, Ole; Hansen, Jan; Brunak, Søren

    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...... divided into chirality constraints and distance constraints. Here we report that the problem of mirrored structures, in some cases, can be solved by using a chirality term in the cost function....... 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...

  5. Data assimilation with inequality constraints

    Science.gov (United States)

    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.

  6. Automated External Defibrillator

    Science.gov (United States)

    ... To Health Topics / Automated External Defibrillator Automated External Defibrillator Also known as What Is An automated external ... in survival. Training To Use an Automated External Defibrillator Learning how to use an AED and taking ...

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

    International Nuclear Information System (INIS)

    Dreicer, M.; Tort, V.; Manen, P.

    1995-01-01

    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. Prostate Specific Antigen (PSA) as Predicting Marker for Clinical Outcome and Evaluation of Early Toxicity Rate after High-Dose Rate Brachytherapy (HDR-BT) in Combination with Additional External Beam Radiation Therapy (EBRT) for High Risk Prostate Cancer.

    Science.gov (United States)

    Ecke, Thorsten H; Huang-Tiel, Hui-Juan; Golka, Klaus; Selinski, Silvia; Geis, Berit Christine; Koswig, Stephan; Bathe, Katrin; Hallmann, Steffen; Gerullis, Holger

    2016-11-10

    High-dose-rate brachytherapy (HDR-BT) with external beam radiation therapy (EBRT) is a common treatment option for locally advanced prostate cancer (PCa). Seventy-nine male patients (median age 71 years, range 50 to 79) with high-risk PCa underwent HDR-BT following EBRT between December 2009 and January 2016 with a median follow-up of 21 months. HDR-BT was administered in two treatment sessions (one week interval) with 9 Gy per fraction using a planning system and the Ir192 treatment unit GammaMed Plus iX. EBRT was performed with CT-based 3D-conformal treatment planning with a total dose administration of 50.4 Gy with 1.8 Gy per fraction and five fractions per week. Follow-up for all patients was organized one, three, and five years after radiation therapy to evaluate early and late toxicity side effects, metastases, local recurrence, and prostate-specific antigen (PSA) value measured in ng/mL. The evaluated data included age, PSA at time of diagnosis, PSA density, BMI (body mass index), Gleason score, D'Amico risk classification for PCa, digital rectal examination (DRE), PSA value after one/three/five year(s) follow-up (FU), time of follow-up, TNM classification, prostate volume, and early toxicity rates. Early toxicity rates were 8.86% for gastrointestinal, and 6.33% for genitourinary side effects. Of all treated patients, 84.81% had no side effects. All reported complications in early toxicity were grade 1. PSA density at time of diagnosis ( p = 0.009), PSA on date of first HDR-BT ( p = 0.033), and PSA on date of first follow-up after one year ( p = 0.025) have statistical significance on a higher risk to get a local recurrence during follow-up. HDR-BT in combination with additional EBRT in the presented design for high-risk PCa results in high biochemical control rates with minimal side-effects. PSA is a negative predictive biomarker for local recurrence during follow-up. A longer follow-up is needed to assess long-term outcome and toxicities.

  9. Composing constraint solvers

    NARCIS (Netherlands)

    P. Zoeteweij (Peter)

    2005-01-01

    htmlabstractComposing constraint solvers based on tree search and constraint propagation through generic iteration leads to efficient and flexible constraint solvers. This was demonstrated using OpenSolver, an abstract branch-and-propagate tree search engine that supports a wide range of relevant

  10. The external cruising costs of parking

    NARCIS (Netherlands)

    Inci, E.; van Ommeren, J.N.; Kobus, Martijn

    2017-01-01

    Existing work emphasizes the importance of traffic congestion externalities, but typically ignores cruising-for-parking externalities. We estimate the marginal external cruising costs of parking—that is, the time costs that an additional parked car imposes on drivers by inducing them to cruise for

  11. Constraints meet concurrency

    CERN Document Server

    Mauro, Jacopo

    2014-01-01

    This book describes the benefits that emerge when the fields of constraint programming and concurrency meet. On the one hand, constraints can be used in concurrency theory to increase the conciseness and the expressive power of concurrent languages from a pragmatic point of view. On the other hand, problems modeled by using constraints can be solved faster and more efficiently using a concurrent system. Both directions are explored providing two separate lines of development. Firstly the expressive power of a concurrent language is studied, namely Constraint Handling Rules, that supports constraints as a primitive construct. The features of this language which make it Turing powerful are shown. Then a framework is proposed to solve constraint problems that is intended to be deployed on a concurrent system. For the development of this framework the concurrent language Jolie following the Service Oriented paradigm is used. Based on this experience, an extension to Service Oriented Languages is also proposed in ...

  12. Matchings with Externalities and Attitudes

    DEFF Research Database (Denmark)

    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...... 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. Under this framework, we analyze many-to-many matchings and one-to-one matchings...

  13. Constraint Optimization Literature Review

    Science.gov (United States)

    2015-11-01

    constraint propagation techniques, see Bessière (2006). 3.1.3 Depth-First Search Depth-first search (also called backtracking search) is a trial-and...any constraints, the algorithm backtracks by unassigning the most recent variable binding and reassigning the variable to a different value. If all...to a solution, so choosing the value that is least likely to cause a constraint violation reduces the chance that it will be necessary to backtrack

  14. Temporal Concurrent Constraint Programming

    DEFF Research Database (Denmark)

    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...... reflect the reactive interactions between concurrent constraint processes and their environment, as well as internal interactions between individual processes. Relationships between the suggested notions are studied, and they are all proved to be decidable for a substantial fragment of the calculus...

  15. Temporal Concurrent Constraint Programming

    DEFF Research Database (Denmark)

    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...

  16. Theory of Constraints (TOC)

    DEFF Research Database (Denmark)

    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....

  17. Credit Constraints in Education

    Science.gov (United States)

    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…

  18. Evaluating Distributed Timing Constraints

    DEFF Research Database (Denmark)

    Kristensen, C.H.; Drejer, N.

    1994-01-01

    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....

  19. Constraints in Quantum Geometrodynamics

    Science.gov (United States)

    Gentle, Adrian P.; George, Nathan D.; Miller, Warner A.; Kheyfets, Arkady

    We compare different treatments of the constraints in canonical quantum gravity. The standard approach on the superspace of 3-geometries treats the constraints as the sole carriers of the dynamic content of the theory, thus rendering the traditional dynamical equations obsolete. Quantization of the constraints in both the Dirac and ADM square root Hamiltonian approaches leads to the well known problems of time evolution. These problems of time are of both an interpretational and technical nature. In contrast, the geometrodynamic quantization procedure on the superspace of the true dynamical variables separates the issues of quantization from the enforcement of the constraints. The resulting theory takes into account states that are off-shell with respect to the constraints, and thus avoids the problems of time. We develop, for the first time, the geometrodynamic quantization formalism in a general setting and show that it retains all essential features previously illustrated in the context of homogeneous cosmologies.

  20. Estimating externalities of biomass fuel cycles, Report 7

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Constraint-based reachability

    Directory of Open Access Journals (Sweden)

    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.

  2. Financial frictions and substitution between internal and external funds in publicly traded Brazilian companies

    Directory of Open Access Journals (Sweden)

    Márcio Telles Portal

    2012-04-01

    Full Text Available The present study aimed to document the effects of financial constraints on the negative relationship between cash flow and external funds, a phenomenon associated with the Pecking Order Theory. This theory suggests that companies subject to more expensive external funds (financially constrained firms should demonstrate a stronger negative relationship with cash flow than companies subject to minor financial frictions (financially unconstrained firms. The results indicate that the external funds of constrained firms consistently present less negative sensitivity to cash flow compared with those of unconstrained companies. Additionally, the internal funds of constrained companies demonstrate a positive sensitivity to cash flow, whereas those of unconstrained companies do not show any such significant behavior. These results are in accordance with the findings of Almeida and Campello (2010, who suggest the following: first, because of the endogenous nature of investment decisions in constrained companies, the complementary relationship between internal and external funds prevails over the substitutive effects suggested by the Pecking Order Theory; and second, the negative relationship between cash flow and external funds cannot be interpreted as evidence of costly external funds and therefore does not corroborate the Pecking Order Theory.

  3. Seismological Constraints on Geodynamics

    Science.gov (United States)

    Lomnitz, C.

    2004-12-01

    Earth is an open thermodynamic system radiating heat energy into space. A transition from geostatic earth models such as PREM to geodynamical models is needed. We discuss possible thermodynamic constraints on the variables that govern the distribution of forces and flows in the deep Earth. In this paper we assume that the temperature distribution is time-invariant, so that all flows vanish at steady state except for the heat flow Jq per unit area (Kuiken, 1994). Superscript 0 will refer to the steady state while x denotes the excited state of the system. We may write σ 0=(J{q}0ṡX{q}0)/T where Xq is the conjugate force corresponding to Jq, and σ is the rate of entropy production per unit volume. Consider now what happens after the occurrence of an earthquake at time t=0 and location (0,0,0). The earthquake introduces a stress drop Δ P(x,y,z) at all points of the system. Response flows are directed along the gradients toward the epicentral area, and the entropy production will increase with time as (Prigogine, 1947) σ x(t)=σ 0+α {1}/(t+β )+α {2}/(t+β )2+etc A seismological constraint on the parameters may be obtained from Omori's empirical relation N(t)=p/(t+q) where N(t) is the number of aftershocks at time t following the main shock. It may be assumed that p/q\\sim\\alpha_{1}/\\beta times a constant. Another useful constraint is the Mexican-hat geometry of the seismic transient as obtained e.g. from InSAR radar interferometry. For strike-slip events such as Landers the distribution of \\DeltaP is quadrantal, and an oval-shaped seismicity gap develops about the epicenter. A weak outer triggering maxiμm is found at a distance of about 17 fault lengths. Such patterns may be extracted from earthquake catalogs by statistical analysis (Lomnitz, 1996). Finally, the energy of the perturbation must be at least equal to the recovery energy. The total energy expended in an aftershock sequence can be found approximately by integrating the local contribution over

  4. Short-sale Constraints and Credit Runs

    DEFF Research Database (Denmark)

    Venter, Gyuri

    This paper studies how short-sale constraints affect the informational efficiency of market prices and the link between prices and economic activity. I show that under short-sale constraints security prices contain less information. However, short-sale constraints increase the informativeness...... of prices to some agents who learn about the quality of an investment opportunity from market prices and have additional private information. Then I apply this observation when modeling a run on an investment bank by its short-term creditors, who are endowed with dispersed information and also learn from...

  5. Network Design with Node Degree Balance Constraints

    DEFF Research Database (Denmark)

    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....

  6. A Hybrid Programming Framework for Modeling and Solving Constraint Satisfaction and Optimization Problems

    Directory of Open Access Journals (Sweden)

    Paweł Sitek

    2016-01-01

    Full Text Available This paper proposes a hybrid programming framework for modeling and solving of constraint satisfaction problems (CSPs and constraint optimization problems (COPs. Two paradigms, CLP (constraint logic programming and MP (mathematical programming, are integrated in the framework. The integration is supplemented with the original method of problem transformation, used in the framework as a presolving method. The transformation substantially reduces the feasible solution space. The framework automatically generates CSP and COP models based on current values of data instances, questions asked by a user, and set of predicates and facts of the problem being modeled, which altogether constitute a knowledge database for the given problem. This dynamic generation of dedicated models, based on the knowledge base, together with the parameters changing externally, for example, the user’s questions, is the implementation of the autonomous search concept. The models are solved using the internal or external solvers integrated with the framework. The architecture of the framework as well as its implementation outline is also included in the paper. The effectiveness of the framework regarding the modeling and solution search is assessed through the illustrative examples relating to scheduling problems with additional constrained resources.

  7. Resources, constraints and capabilities

    NARCIS (Netherlands)

    Dhondt, S.; Oeij, P.R.A.; Schröder, A.

    2018-01-01

    Human and financial resources as well as organisational capabilities are needed to overcome the manifold constraints social innovators are facing. To unlock the potential of social innovation for the whole society new (social) innovation friendly environments and new governance structures

  8. Dynamics and causality constraints

    International Nuclear Information System (INIS)

    Sousa, Manoelito M. de

    2001-04-01

    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)

  9. ExternE National Implementation Finland

    International Nuclear Information System (INIS)

    Pingoud, K.; Maelkki, H.; Wihersaari, M.; Pirilae, P.; Hongisto, M.; Siitonen, S.; Johansson, M.

    1999-01-01

    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.)

  10. ExternE National Implementation Finland

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  11. Investment Timing When External Financing Is Costly

    DEFF Research Database (Denmark)

    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. ASH External Web Portal (External Portal) -

    Data.gov (United States)

    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...

  13. Misconceptions and constraints

    International Nuclear Information System (INIS)

    Whitten, M.; Mahon, R.

    2005-01-01

    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)

  14. Colored, spinning classical particle in an external non-Abelian gauge field

    International Nuclear Information System (INIS)

    Arodz, H.

    1982-04-01

    Classical non-relativistic equations of motion are derived for a colored, spinning point-like particle in an external SU(2) gauge field from Dirac equation. It is found that in addition to the classical spin and color spin vectors, S, I, it is necessary to introduce a new classical dynamical variable [Jsup(ab)], a,b = 1,2,3, describing a mixing of the spin and color. The constraint relations between [Jsup(ab)], S, I are also found. (Auth.)

  15. The External Nasal Valve.

    Science.gov (United States)

    Hamilton, Grant S

    2017-05-01

    The external nasal valve is a complex entity comprised of multiple structures and tissue types. As such, there is no single operation that can address all problems of the external valve. This article reviews the relevant anatomy, pathologic conditions, and treatments for external nasal valve dysfunction, including a detailed review of the nasal muscles and their contribution to external nasal valve patency. Surgical and nonsurgical options for treatment and the evidence supporting the importance of proper external nasal valve function on quality-of-life measures are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Occupational dose constraint

    International Nuclear Information System (INIS)

    Heilbron Filho, Paulo Fernando Lavalle; Xavier, Ana Maria

    2005-01-01

    The revision process of the international radiological protection regulations has resulted in the adoption of new concepts, such as practice, intervention, avoidable and restriction of dose (dose constraint). The latter deserving of special mention since it may involve reducing a priori of the dose limits established both for the public and to individuals occupationally exposed, values that can be further reduced, depending on the application of the principle of optimization. This article aims to present, with clarity, from the criteria adopted to define dose constraint values to the public, a methodology to establish the dose constraint values for occupationally exposed individuals, as well as an example of the application of this methodology to the practice of industrial radiography

  17. Psychological constraints on egalitarianism

    DEFF Research Database (Denmark)

    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...

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

    CERN Document Server

    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...

  19. Theory and practice of internalization of external costs

    International Nuclear Information System (INIS)

    Bonus, H.

    1995-01-01

    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

  20. Renewable energy: Externality costs as market barriers

    International Nuclear Information System (INIS)

    Owen, Anthony D.

    2006-01-01

    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

  1. Ecosystems emerging. 5: Constraints

    Czech Academy of Sciences Publication Activity Database

    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

  2. Temporal Concurrent Constraint Programming

    DEFF Research Database (Denmark)

    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...

  3. Constraints on Dbar uplifts

    International Nuclear Information System (INIS)

    Alwis, S.P. de

    2016-01-01

    We discuss constraints on KKLT/KKLMMT and LVS scenarios that use anti-branes to get an uplift to a deSitter vacuum, coming from requiring the validity of an effective field theory description of the physics. We find these are not always satisfied or are hard to satisfy.

  4. Coordinative constraints in bimanual tool use.

    Science.gov (United States)

    Massen, Cristina; Sattler, Christine

    2010-09-01

    This study investigates coordinative constraints when participants execute discrete bimanual tool use actions. Participants moved two levers to targets that were either presented near the proximal parts of the levers or near the distal tips of the levers. In the first case, the tool transformation (i.e. the relationship between hand movement direction and target direction) was compatible, whereas in the second case, it was incompatible. We hypothesized that an egocentric constraint (i.e. a preference for moving the hands and tools in a mirror-symmetrical fashion) would be dominant when targets are presented near the proximal parts of the levers because in this situation, movements can be coded in terms of body-related coordinates. Furthermore, an allocentric constraint (i.e. a preference to move the hands in the same (parallel) direction in extrinsic space) was expected to be dominant when one of the targets or both are presented near the distal parts of the levers because in this condition, movements have to be coded in an external reference frame. The results show that when both targets are presented near the proximal parts of the levers, participants are faster and produce less errors with mirror-symmetrical when compared to parallel movements. Furthermore, the RT mirror-symmetry advantage is eliminated, when both targets are presented near the distal parts of the levers, and it is reversed, when the target for one lever is presented near its distal part and the target for the other lever is presented near its proximal part. These results show that the dominance of egocentric and allocentric coordinative constraints in bimanual tool use depends on whether movements are coded in terms of body-related coordinates or in an external reference frame.

  5. Topology optimized and 3D printed polymer-bonded permanent magnets for a predefined external field

    Science.gov (United States)

    Huber, C.; Abert, C.; Bruckner, F.; Pfaff, C.; Kriwet, J.; Groenefeld, M.; Teliban, I.; Vogler, C.; Suess, D.

    2017-08-01

    Topology optimization offers great opportunities to design permanent magnetic systems that have specific external field characteristics. Additive manufacturing of polymer-bonded magnets with an end-user 3D printer can be used to manufacture permanent magnets with structures that had been difficult or impossible to manufacture previously. This work combines these two powerful methods to design and manufacture permanent magnetic systems with specific properties. The topology optimization framework is simple, fast, and accurate. It can also be used for the reverse engineering of permanent magnets in order to find the topology from field measurements. Furthermore, a magnetic system that generates a linear external field above the magnet is presented. With a volume constraint, the amount of magnetic material can be minimized without losing performance. Simulations and measurements of the printed systems show very good agreement.

  6. Behavioural Constraints on Practices of Auditing in Nigeria (BCPAN)

    Science.gov (United States)

    Akpomi, Margaret E.; Amesi, Joy

    2009-01-01

    This research was conducted to determine the behavioural constraints on practices of auditing (BCPAN) in Nigeria and to proffer strategies for making incidence of auditing (internal and external auditors) more effective. Thirty-seven administrators drawn from some public limited liability companies, private companies and tertiary institutions were…

  7. Clean development mechanism and off-grid small-scale hydropower projects: Evaluation of additionality

    International Nuclear Information System (INIS)

    Tanwar, Nitin

    2007-01-01

    The global climate change mitigation policies and their stress on sustainable development have made electrification of rural mountainous villages, using small hydro, an attractive destination for potential clean development mechanism (CDM) projects. This invariably involves judging the additionality of such projects. The paper suggests a new approach to judge the additionality of such stand-alone small hydropower projects. This has been done by breaking up additionality into two components: external and local. The external additionality is project developer dependent. For determining the local additionality, the paper takes into account the probability of a village getting electrified over a period of time, which is kept equal to the possible crediting period. This is done by defining an electrification factor (EF) whose value depends on the degree of isolation, financial constraints and institutional constraints encountered while electrifying a mountainous village. Using this EF, the additionality of a CDM project can be judged in a much easier and accurate way. The paper is based on the data and inputs gathered during site visits to many isolated villages located in the eastern Indian Himalayas

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

    Energy Technology Data Exchange (ETDEWEB)

    de Leon, M. [Instituto de Matematicas y Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 123, 28006 Madrid (Spain); de Diego, D.M. [Departamento de Economia Aplicada Cuantitativa, Facultad de Ciencias Economicas y Empresariales, UNED, 28040 Madrid (Spain)

    1997-06-01

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

  9. Food additives

    Science.gov (United States)

    ... 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 ...

  10. Additional external electromagnetic fields for laser microprocessing of metals.

    Science.gov (United States)

    Schütz, V; Bischoff, K; Brief, S; Koch, J; Suttmann, O; Overmeyer, L

    2016-11-14

    Ultra-short pulsed laser processing is a potent tool for microstructuring of a lot of materials. At certain laser parameters, particular periodical and/or quasi-periodical µm-size surface structures evolve apparently during processing. With extended plasmonics theory, it is possible to predict the structure formation, and a systematic technology can be derived to alter the surface for laser processing. In this work, we have demonstrated the modification of the laser processing with applying tailored dynamic surface electro-magnetic fields. Possible improvement in applications is seen in the fields of process efficiency of laser ablation and a superior control of the surface topography.

  11. The NCL natural constraint language

    CERN Document Server

    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.

  12. Parallel Handling of Integrity Constraints

    NARCIS (Netherlands)

    Grefen, P.W.P.J.; Flokstra, Jan; Apers, Peter M.G.

    1990-01-01

    Integrity constraints form an important part of a data model. Therefore, a complete integrity constraint handling subsystem is considered an important part of any modern DBMS. In implementing an integrity constraint handling subsystem, there are two major problem areas: providing enough

  13. [External cephalic version].

    Science.gov (United States)

    Navarro-Santana, B; Duarez-Coronado, M; Plaza-Arranz, J

    2016-08-01

    To analyze the rate of successful external cephalic versions in our center and caesarean sections that would be avoided with the use of external cephalic versions. From January 2012 to March 2016 external cephalic versions carried out at our center, which were a total of 52. We collected data about female age, gestational age at the time of the external cephalic version, maternal body mass index (BMI), fetal variety and situation, fetal weight, parity, location of the placenta, amniotic fluid index (ILA), tocolysis, analgesia, and newborn weight at birth, minor adverse effects (dizziness, hypotension and maternal pain) and major adverse effects (tachycardia, bradycardia, decelerations and emergency cesarean section). 45% of the versions were unsuccessful and 55% were successful. The percentage of successful vaginal delivery in versions was 84% (4% were instrumental) and 15% of caesarean sections. With respect to the variables studied, only significant differences in birth weight were found; suggesting that birth weight it is related to the outcome of external cephalic version. Probably we did not find significant differences due to the number of patients studied. For women with breech presentation, we recommend external cephalic version before the expectant management or performing a cesarean section. The external cephalic version increases the proportion of fetuses in cephalic presentation and also decreases the rate of caesarean sections.

  14. Utility maximization under solvency constraints and unhedgeable risks

    NARCIS (Netherlands)

    Kleinow, T.; Pelsser, A.

    2008-01-01

    We consider the utility maximization problem for an investor who faces a solvency or risk constraint in addition to a budget constraint. The investor wishes to maximize her expected utility from terminal wealth subject to a bound on her expected solvency at maturity. We measure solvency using a

  15. Additive manufacturing.

    Science.gov (United States)

    Mumith, A; Thomas, M; Shah, Z; Coathup, M; Blunn, G

    2018-04-01

    Increasing innovation in rapid prototyping (RP) and additive manufacturing (AM), also known as 3D printing, is bringing about major changes in translational surgical research. This review describes the current position in the use of additive manufacturing in orthopaedic surgery. Cite this article: Bone Joint J 2018;100-B:455-60.

  16. Integrating Building Functions into Massive External Walls

    Directory of Open Access Journals (Sweden)

    Ahmed Hisham Hafez

    2017-11-01

    Full Text Available Well into the twentieth century, brick and stone were the materials used. Bricklaying and stonemasonry were the construction technologies employed for the exterior walls of virtually all major structures. However, with the rise in quality of life, the massive walls alone became incapable of fulfilling all the developed needs. Adjacent systems and layers had then to be attached to the massive layer. Nowadays, the external wall is usually composed of a layered construction. Each external wall function is usually represented by a separate layer or system. The massive layer of the wall is usually responsible for the load-bearing function. Traditional massive external walls vary in terms of their external appearance, their composition and attached layers. However, their design and construction process is usually a repeated process. It is a linear process where each discipline is concerned with a separate layer or system. These disciplines usually take their tasks away and bring them back to be re-integrated in a layered manner. New massive technologies with additional function have recently become available. Such technologies can provide the external wall with other functions in addition to its load-bearing function. The purpose of this research is to map the changes required to the traditional design and construction process when massive technologies with additional function are applied in external walls. Moreover, the research aims at assessing the performance of massive solutions with additional function when compared to traditional solutions in two different contexts, the Netherlands and Egypt. Through the analysis of different additional function technologies in external walls, a guidance scheme for different stakeholders is generated. It shows the expected process changes as related to the product level and customization level. Moreover, the research concludes that the performance of additional insulating technologies, and specifically

  17. Motor coordination uses external spatial coordinates independent of developmental vision.

    Science.gov (United States)

    Heed, Tobias; Röder, Brigitte

    2014-07-01

    The constraints that guide bimanual movement coordination are informative about the processing principles underlying movement planning in humans. For example, symmetry relative to the body midline benefits finger and hand movements independent of hand posture. This symmetry constraint has been interpreted to indicate that movement coordination is guided by a perceptual code. Although it has been assumed implicitly that the perceptual system at the heart of this constraint is vision, this relationship has not been tested. Here, congenitally blind and sighted participants made symmetrical and non-symmetrical (that is, parallel) bimanual tapping and finger oscillation movements. For both groups, symmetrical movements were executed more correctly than parallel movements, independent of anatomical constraints like finger homology and hand posture. For the blind, the reliance on external spatial factors in movement coordination stands in stark contrast to their use of an anatomical reference frame in perceptual processing. Thus, the externally coded symmetry constraint evident in bimanual coordination can develop in the absence of the visual system, suggesting that the visual system is not critical for the establishment of an external-spatial reference frame in movement coordination. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Reduction Of Constraints For Coupled Operations

    International Nuclear Information System (INIS)

    Raszewski, F.; Edwards, T.

    2009-01-01

    The homogeneity constraint was implemented in the Defense Waste Processing Facility (DWPF) Product Composition Control System (PCCS) to help ensure that the current durability models would be applicable to the glass compositions being processed during DWPF operations. While the homogeneity constraint is typically an issue at lower waste loadings (WLs), it may impact the operating windows for DWPF operations, where the glass forming systems may be limited to lower waste loadings based on fissile or heat load limits. In the sludge batch 1b (SB1b) variability study, application of the homogeneity constraint at the measurement acceptability region (MAR) limit eliminated much of the potential operating window for DWPF. As a result, Edwards and Brown developed criteria that allowed DWPF to relax the homogeneity constraint from the MAR to the property acceptance region (PAR) criterion, which opened up the operating window for DWPF operations. These criteria are defined as: (1) use the alumina constraint as currently implemented in PCCS (Al 2 O 3 (ge) 3 wt%) and add a sum of alkali constraint with an upper limit of 19.3 wt% (ΣM 2 O 2 O 3 constraint to 4 wt% (Al 2 O 3 (ge) 4 wt%). Herman et al. previously demonstrated that these criteria could be used to replace the homogeneity constraint for future sludge-only batches. The compositional region encompassing coupled operations flowsheets could not be bounded as these flowsheets were unknown at the time. With the initiation of coupled operations at DWPF in 2008, the need to revisit the homogeneity constraint was realized. This constraint was specifically addressed through the variability study for SB5 where it was shown that the homogeneity constraint could be ignored if the alumina and alkali constraints were imposed. Additional benefit could be gained if the homogeneity constraint could be replaced by the Al 2 O 3 and sum of alkali constraint for future coupled operations processing based on projections from Revision 14 of

  19. Initial external events: floods

    International Nuclear Information System (INIS)

    Drumond, M.M.

    1989-12-01

    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.)

  20. Energy policy and externalities

    International Nuclear Information System (INIS)

    Bertel, E.; Fraser, P.

    2002-01-01

    External costs of energy have been assessed in a number of authoritative and reliable studies based upon widely accepted methodologies such as life cycle analysis (LCA). However, although those costs are recognised by most stakeholders and decision makers, results from analytical work on externalities and LCA studies are seldom used in policy making. The International Energy Agency (IEA) and the Nuclear Energy Agency (NEA) convened a joint workshop in November 2001 to offer experts and policy makers an opportunity to present state-of-the-art results from analytical work on externalities and debate issues related to the relevance of external costs and LCA for policy-making purposes. The findings from the workshop highlight the need for further work in the field and the potential rote of international organisations like the IEA and the NEA in this context. (authors)

  1. Externally Verifiable Oblivious RAM

    Directory of Open Access Journals (Sweden)

    Gancher Joshua

    2017-04-01

    Full Text Available We present the idea of externally verifiable oblivious RAM (ORAM. Our goal is to allow a client and server carrying out an ORAM protocol to have disputes adjudicated by a third party, allowing for the enforcement of penalties against an unreliable or malicious server. We give a security definition that guarantees protection not only against a malicious server but also against a client making false accusations. We then give modifications of the Path ORAM [15] and Ring ORAM [9] protocols that meet this security definition. These protocols both have the same asymptotic runtimes as the semi-honest original versions and require the external verifier to be involved only when the client or server deviates from the protocol. Finally, we implement externally verified ORAM, along with an automated cryptocurrency contract to use as the external verifier.

  2. Future of External Reporting

    Science.gov (United States)

    Powers, Kristina

    2015-01-01

    This chapter builds on prior chapters and focuses on higher education trends on the horizon and the resulting impact on external reporting for institutional researchers. Three practical recommendations and examples for institutional researchers are also presented.

  3. Externalities of energy and atomic power

    International Nuclear Information System (INIS)

    2006-09-01

    Energy technology ensures not only energy supply but also has great impacts on society and environments. Economical value and effect evaluation alone doesn't mean appropriate so the evaluation of 'externalities' should be appreciated. In order to assess atomic power in this context, the Atomic Energy Society of Japan set up a research committee on 'externalities of energy and atomic power' from April 2002 to March 2006, whose activities were described in this report. In addition to environmental effects and environmental externalities, four areas were newly studied as follows: (1) biological effects of low dose rate exposure and externalities, (2) externalities as social/economical effects including stable supply and security, (3) energy technologies evaluation and (4) social choice and decision-making. (T. Tanaka)

  4. Design with Nonlinear Constraints

    KAUST Repository

    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.

  5. Guide for External Beam Radiotherapy. Procedures 2007

    International Nuclear Information System (INIS)

    Ardiet, Jean-Michel; Bourhis, Jean; Eschwege, Francois; Gerard, Jean-Pierre; Martin, Philippe; Mazeron, Jean-Jacques; Barillot, Isabelle; Bey, Pierre; Cosset, Jean-Marc; Thomas, Olivier; Bolla, Michel; Bourguignon, Michel; Godet, Jean-Luc; Krembel, David; Valero, Marc; Bara, Christine; Beauvais-March, Helene; Derreumaux, Sylvie; Vidal, Jean-Pierre; Drouard, Jean; Sarrazin, Thierry; Lindecker-Cournil, Valerie; Robin, Sun Hee Lee; Thevenet, Nicolas; Depenweiller, Christian; Le Tallec, Philippe; Ortholan, Cecile; Aimone, Nicole; Baldeschi, Carine; Cantelli, Andree; Estivalet, Stephane; Le Prince, Cyrille; QUERO, Laurent; Costa, Andre; Gerard, Jean-Pierre; Ardiet, Jean-Michel; Bensadoun, Rene-Jean; Bourhis, Jean; Calais, Gilles; Lartigau, Eric; Ginot, Aurelie; Girard, Nicolas; Mornex, Francoise; Bolla, Michel; Chauvet, Bruno; Maingon, Philippe; Martin, Etienne; Azria, David; Gerard, Jean-Pierre; Grehange, Gilles; Hennequin, Christophe; Peiffert, Didier; Toledano, Alain; Belkacemi, Yazid; Courdi, Adel; Belliere, Aurelie; Peignaux, Karine; Mahe, Marc; Bondiau, Pierre-Yves; Kantor, Guy; Lepechoux, Cecile; Carrie, Christian; Claude, Line

    2007-01-01

    In order to optimize quality and security in the delivery of radiation treatment, the French SFRO (Societe francaise de radiotherapie oncologique) is publishing a Guide for Radiotherapy. This guide is realized according to the HAS (Haute Autorite de sante) methodology of 'structured experts consensus'. This document is made of two parts: a general description of external beam radiation therapy and chapters describing the technical procedures of the main tumors to be irradiated (24). For each procedure, a special attention is given to dose constraints in the organs at risk. This guide will be regularly updated

  6. Oil Dependence, Climate Change and Energy Security: Will Constraints on Oil Shape our Climate Future or Vice Versa?

    Science.gov (United States)

    Mignone, B. K.

    2008-12-01

    Threats to US and global energy security take several forms. First, the overwhelming dependence on oil in the transport sector leaves the US economy (and others) vulnerable to supply shocks and price volatility. Secondly, the global dependence on oil inflates prices and enhances the transfer of wealth to authoritarian regimes. Finally, the global reliance on fossil fuels more generally jeopardizes the stability of the climate system. These three threats - economic, strategic and environmental - can only be mitigated through a gradual substitution away from fossil fuels (both coal and oil) on a global scale. Such large-scale substitution could occur in response to potential resource constraints or in response to coordinated government policies in which these externalities are explicitly internalized. Here, I make use of a well-known integrated assessment model (MERGE) to examine both possibilities. When resource limits are considered alone, global fuel use tends to shift toward even more carbon-intensive resources, like oil shale or liquids derived from coal. On the other hand, when explicit carbon constraints are imposed, the fuel sector response is more complex. Generally, less stringent climate targets can be satisfied entirely through reductions in global coal consumption, while more stringent targets require simultaneous reductions in both coal and oil consumption. Taken together, these model results suggest that resource constraints alone will only exacerbate the climate problem, while a subset of policy-driven carbon constraints may yield tangible security benefits (in the form of reduced global oil consumption) in addition to the intended environmental outcome.

  7. Cosmographic Constraints and Cosmic Fluids

    Directory of Open Access Journals (Sweden)

    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.

  8. Solving Sudoku with Constraint Programming

    Science.gov (United States)

    Crawford, Broderick; Castro, Carlos; Monfroy, Eric

    Constraint Programming (CP) is a powerful paradigm for modeling and solving Complex Combinatorial Problems (generally issued from Decision Making). In this work, we model the known Sudoku puzzle as a Constraint Satisfaction Problems and solve it with CP comparing the performance of different Variable and Value Selection Heuristics in its Enumeration phase. We encourage this kind of benchmark problem because it may suggest new techniques in constraint modeling and solving of complex systems, or aid the understanding of its main advantages and limits.

  9. Productivity Change and Externalities

    DEFF Research Database (Denmark)

    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...... firms and the economy as a whole. The approach used in the current research accounts for different internal as well as external factors that individual firms face and evaluates the effect on changes in productivity, technology as well as the efficiency of domestic firms. The empirical analysis focuses...... 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 efficiency...

  10. Phosphazene additives

    Science.gov (United States)

    Harrup, Mason K; Rollins, Harry W

    2013-11-26

    An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

  11. Minimal Flavor Constraints for Technicolor

    DEFF Research Database (Denmark)

    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 mas......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...

  12. Constraint rescaling in refined algebraic quantisation: Momentum constraint

    International Nuclear Information System (INIS)

    Louko, Jorma; Martinez-Pascual, Eric

    2011-01-01

    We investigate refined algebraic quantisation within a family of classically equivalent constrained Hamiltonian systems that are related to each other by rescaling a momentum-type constraint. The quantum constraint is implemented by a rigging map that is motivated by group averaging but has a resolution finer than what can be peeled off from the formally divergent contributions to the averaging integral. Three cases emerge, depending on the asymptotics of the rescaling function: (i) quantisation is equivalent to that with identity scaling; (ii) quantisation fails, owing to nonexistence of self-adjoint extensions of the constraint operator; (iii) a quantisation ambiguity arises from the self-adjoint extension of the constraint operator, and the resolution of this purely quantum mechanical ambiguity determines the superselection structure of the physical Hilbert space. Prospects of generalising the analysis to systems with several constraints are discussed.

  13. Checklists for external validity

    DEFF Research Database (Denmark)

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

    2014-01-01

    to an implementation setting. In this paper, currently available checklists on external validity are identified, assessed and used as a basis for proposing a new improved instrument. METHOD: A systematic literature review was carried out in Pubmed, Embase and Cinahl on English-language papers without time restrictions...

  14. External costs of electricity

    International Nuclear Information System (INIS)

    Rabl, A.; Spadaro, J.V.

    2005-01-01

    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.)

  15. On parabolic external maps

    DEFF Research Database (Denmark)

    Lomonaco, Luna; Petersen, Carsten Lunde; Shen, Weixiao

    2017-01-01

    We prove that any C1+BV degree d ≥ 2 circle covering h having all periodic orbits weakly expanding, is conjugate by a C1+BV diffeomorphism to a metrically expanding map. We use this to connect the space of parabolic external maps (coming from the theory of parabolic-like maps) to metrically expan...

  16. Network cities and externalities

    Directory of Open Access Journals (Sweden)

    Rafael Boix Domènech

    2004-01-01

    Full Text Available The concept of «agglomeration economies» explains the existence of advantages derived from the concentration of population and activity. However, it does not explain the existence of spatially dynamic external economies. Network economies generated in networks of cities correspond to this last type, since they are generated from the interaction between urban units, linked by a network relationship. The objective of this research is to advance in the study of the relationship between the networks of cities and the generation of external economies. The research is divided in four parts: first we expose the link between networks of cities and external economies. The second part outlines a model for the combined measuring of the concentration and network economies. The third part explains the results of applying the model to a case of study: the network of cities of Catalonia. The results suggest that there is a causal relationship between the organization of the urban units forming networks of cities and the generation of external economies that affect growth and economic development. Finally, conclusions and policy implications are drawn up.

  17. External Otitis (Swimmer's Ear)

    Science.gov (United States)

    ... an otoscope for redness, swelling, and pus. Debris removal, antibiotic ear drops, keeping water out of the ear, and pain relievers are ... cleaning it (using cotton-tipped swabs) or getting water or irritants, such as hair spray or hair dye, in the canal often leads to external otitis. ...

  18. Domain general constraints on statistical learning.

    Science.gov (United States)

    Thiessen, Erik D

    2011-01-01

    All theories of language development suggest that learning is constrained. However, theories differ on whether these constraints arise from language-specific processes or have domain-general origins such as the characteristics of human perception and information processing. The current experiments explored constraints on statistical learning of patterns, such as the phonotactic patterns of an infants' native language. Infants in these experiments were presented with a visual analog of a phonotactic learning task used by J. R. Saffran and E. D. Thiessen (2003). Saffran and Thiessen found that infants' phonotactic learning was constrained such that some patterns were learned more easily than other patterns. The current results indicate that infants' learning of visual patterns shows the same constraints as infants' learning of phonotactic patterns. This is consistent with theories suggesting that constraints arise from domain-general sources and, as such, should operate over many kinds of stimuli in addition to linguistic stimuli. © 2011 The Author. Child Development © 2011 Society for Research in Child Development, Inc.

  19. Sustainability constraints on UK bioenergy development

    International Nuclear Information System (INIS)

    Thornley, Patricia; Upham, Paul; Tomei, Julia

    2009-01-01

    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)

  20. Integrity Constraints in Trust Management

    NARCIS (Netherlands)

    Etalle, Sandro; Winsborough, William H.

    We introduce the use, monitoring, and enforcement of integrity constraints in trust managementstyle authorization systems. We consider what portions of the policy state must be monitored to detect violations of integrity constraints. Then we address the fact that not all participants in a trust

  1. On Constraints in Assembly Planning

    Energy Technology Data Exchange (ETDEWEB)

    Calton, T.L.; Jones, R.E.; Wilson, R.H.

    1998-12-17

    Constraints on assembly plans vary depending on product, assembly facility, assembly volume, and many other factors. Assembly costs and other measures to optimize vary just as widely. To be effective, computer-aided assembly planning systems must allow users to express the plan selection criteria that appIy to their products and production environments. We begin this article by surveying the types of user criteria, both constraints and quality measures, that have been accepted by assembly planning systems to date. The survey is organized along several dimensions, including strategic vs. tactical criteria; manufacturing requirements VS. requirements of the automated planning process itself and the information needed to assess compliance with each criterion. The latter strongly influences the efficiency of planning. We then focus on constraints. We describe a framework to support a wide variety of user constraints for intuitive and efficient assembly planning. Our framework expresses all constraints on a sequencing level, specifying orders and conditions on part mating operations in a number of ways. Constraints are implemented as simple procedures that either accept or reject assembly operations proposed by the planner. For efficiency, some constraints are supplemented with special-purpose modifications to the planner's algorithms. Fast replanning enables an interactive plan-view-constrain-replan cycle that aids in constraint discovery and documentation. We describe an implementation of the framework in a computer-aided assembly planning system and experiments applying the system to a number of complex assemblies, including one with 472 parts.

  2. Market segmentation using perceived constraints

    Science.gov (United States)

    Jinhee Jun; Gerard Kyle; Andrew Mowen

    2008-01-01

    We examined the practical utility of segmenting potential visitors to Cleveland Metroparks using their constraint profiles. Our analysis identified three segments based on their scores on the dimensions of constraints: Other priorities--visitors who scored the highest on 'other priorities' dimension; Highly Constrained--visitors who scored relatively high on...

  3. Fixed Costs and Hours Constraints

    Science.gov (United States)

    Johnson, William R.

    2011-01-01

    Hours constraints are typically identified by worker responses to questions asking whether they would prefer a job with more hours and more pay or fewer hours and less pay. Because jobs with different hours but the same rate of pay may be infeasible when there are fixed costs of employment or mandatory overtime premia, the constraint in those…

  4. On the invariance properties of the Klein-Gordon equation with external electromagnetic field

    International Nuclear Information System (INIS)

    Sen Gupta, N.D.

    2003-01-01

    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. (author)

  5. Financial constraints and productivity: evidence from euro area companies

    OpenAIRE

    Ferrando, Annalisa; Ruggieri, Alessandro

    2015-01-01

    In this paper we consider the relation between firms’ financial structure, access to external finance and labor productivity using a large dataset of firm-level data for Euro-area countries during the period 1995-2011. Our empirical strategy is twofold. First we develop an indicator of financial constraints at firm level using a classification based on specific firm characteristics and various measures of financial pressure and liquidity. Second we apply this indicator to a firm-level product...

  6. Efficient and Flexible Crowdsourcing of Specialized Tasks with Precedence Constraints

    OpenAIRE

    Chatterjee, Avhishek; Borokhovich, Michael; Varshney, Lav R.; Vishwanath, Sriram

    2016-01-01

    Many companies now use crowdsourcing to leverage external (as well as internal) crowds to perform specialized work, and so methods of improving efficiency are critical. Tasks in crowdsourcing systems with specialized work have multiple steps and each step requires multiple skills. Steps may have different flexibilities in terms of obtaining service from one or multiple agents, due to varying levels of dependency among parts of steps. Steps of a task may have precedence constraints among them....

  7. Conservation constraints on random matrices

    CERN Document Server

    Ma Wen Jong; Hsieh, J

    2003-01-01

    We study the random matrices constrained by the summation rules that are present in the Hessian of the potential energy surface in the instantaneous normal mode calculations, as a result of momentum conservation. In this paper, we analyse the properties related to such conservation constraints in two classes of real symmetric matrices: one with purely row-wise summation rules and the other with the constraints on the blocks of each matrix, which underscores partially the spatial dimension. We show explicitly that the constraints are removable by separating the degrees of freedom of the zero-eigenvalue modes. The non-spectral degrees of freedom under the constraints can be realized in terms of the ordinary constraint-free orthogonal symmetry but with the rank deducted by the block dimension. We propose that the ensemble of real symmetric matrices with full randomness, constrained by the summation rules, is equivalent to the Gaussian orthogonal ensemble (GOE) with lowered rank. Independent of the joint probabil...

  8. Constraints on astronomical silicate dust

    International Nuclear Information System (INIS)

    Sorrell, W.H.

    1990-01-01

    Numerical radiative-transfer models are used to discuss the properties of circumstellar dust grains around the premain-sequence star AB Aur (HD 31293). It is assumed that the dust consists of a silicate-graphite mixture with Draine and Lee (1984) optical properties. The modeling technique is to match the observed FUV through FIR energy distribution with the spectral energy distribution predicted for a spherical dust shell around a luminous hot star. Special attention is given to matching the observed 10-micron silicate emission feature and the observed circumstellar absorption curve at UV wavelengths, making it possible to strengthen constraints on dust-grain opacity and chemical composition. It is concluded that, although silicate grains can explain the observed 10-micron emission feature, the Draine and Lee silicate-graphite mixture cannot explain the observed FUV circumstellar absorption at the same time. The dust shell around AB Aur contains an additional population of small particles, the most likely candidate being amorphous carbon grains in a nonhydrogenated form. 18 refs

  9. Constraints on astronomical silicate dust

    Science.gov (United States)

    Sorrell, Wilfred H.

    1990-01-01

    Numerical radiative-transfer models are used to discuss the properties of circumstellar dust grains around the premain-sequence star AB Aur (HD 31293). It is assumed that the dust consists of a silicate-graphite mixture with Draine and Lee (1984) optical properties. The modeling technique is to match the observed FUV through FIR energy distribution with the spectral energy distribution predicted for a spherical dust shell around a luminous hot star. Special attention is given to matching the observed 10-micron silicate emission feature and the observed circumstellar absorption curve at UV wavelengths, making it possible to strengthen constraints on dust-grain opacity and chemical composition. It is concluded that, although silicate grains can explain the observed 10-micron emission feature, the Draine and Lee silicate-graphite mixture cannot explain the observed FUV circumstellar absorption at the same time. The dust shell around AB Aur contains an additional population of small particles, the most likely candidate being amorphous carbon grains in a nonhydrogenated form.

  10. Vocabulary Constraint on Texts

    Directory of Open Access Journals (Sweden)

    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.

  11. The External Mind

    DEFF Research Database (Denmark)

    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......, Extended Mind and Distributed Cognition by Claudio Paolucci pp. 69-96 The Social Horizon of Embodied Language and Material Symbols by Riccardo Fusaroli pp. 97-123 Semiotics and Theories of Situated/Distributed Action and Cognition: a Dialogue and Many Intersections by Tommaso Granelli pp. 125-167 Building...... Action in Public Environments with Diverse Semiotic Resources by Charles Goodwin pp. 169-182 How Marking in Dance Constitutes Thinking with the Body by David Kirsh pp. 183-214 Ambiguous Coordination: Collaboration in Informal Science Education Research by Ivan Rosero, Robert Lecusay, Michael Cole pp. 215-240...

  12. Externally triggered microcapsules

    Science.gov (United States)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2011-01-01

    Disclosed are microcapsules comprising a polymer shell enclosing one or more immiscible liquid phases in which a drug or drug precursor are contained in a liquid phase. The microparticles also contain magnetic particles that can be heated by application of an external magnetic field and thus heated to a predetermined Curie temperature. Heating of the particles melts the polymer shell and releases the drug without causing heating of surrounding tissues.

  13. CONSTRAINT PROGRAMMING AND UNIVERSITY TIMETABLING

    Directory of Open Access Journals (Sweden)

    G.W. Groves

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: The technology of Constraint Programming is rapidly becoming a popular alternative for solving large-scale industry problems. This paper provides an introduction to Constraint Programming and to Constraint Logic Programming (CLP, an enabler of constraint programming. The use of Constraint Logic Programming is demonstrated by describing a system developed for scheduling university timetables. Timetabling problems have a high degree of algorithmic complexity (they are usually NP-Complete, and share features with scheduling problems encountered in industry. The system allows the declaration of both hard requirements, which must always be satisfied, and soft constraints which need not be satisfied, though this would be an advantage.

    AFRIKAANSE OPSOMMING: Hierdie artikel beskryf ’n familie van probleem-oplossingstegnieke bekend as “Constraint Programming”, wat al hoe meer gebruik word om groot-skaalse industriële probleme op te los. Die nut van hierdie tegnieke word gedemonstreer deur die beskrywing van ’n skeduleringsisteem om die roosters vir ’n universiteit te genereer. Roosterskeduleringsprobleme is in praktiese gevalle NP-volledig en deel baie eienskappe met industriële skeduleringsprobleme. Die sisteem wat hier beskryf word maak gebruik van beide harde beperkings (wat altyd bevredig moet word en sagte beperkings (bevrediging hiervan is wel voordelig maar dit is opsioneel.

  14. Analysis of optical flow constraints.

    Science.gov (United States)

    Del Bimbo, A; Nesi, P; Sanz, J C

    1995-01-01

    Different constraint equations have been proposed in the literature for the derivation of optical flow. Despite of the large number of papers dealing with computational techniques to estimate optical flow, only a few authors have investigated conditions under which these constraints exactly model the velocity field, that is, the perspective projection on the image plane of the true 3-D velocity. These conditions are analyzed under different hypotheses, and the departures of the constraint equations in modeling the velocity field are derived for different motion conditions. Experiments are also presented giving measures of these departures and of the induced errors in the estimation of the velocity field.

  15. Constraints on relaxation rates for N-level quantum systems

    International Nuclear Information System (INIS)

    Schirmer, S.G.; Solomon, A.I.

    2004-01-01

    We study the constraints imposed on the population and phase relaxation rates by the physical requirement of completely positive evolution for open N-level systems. The Lindblad operators that govern the evolution of the system are expressed in terms of observable relaxation rates, explicit formulas for the decoherence rates due to population relaxation are derived, and it is shown that there are additional, nontrivial constraints on the pure dephasing rates for N>2. Explicit, experimentally testable inequality constraints for the decoherence rates are derived for three- and four-level systems, and the implications of the results are discussed for generic ladder, Λ, and V systems and transitions between degenerate energy levels

  16. Constraints and stability in vector theories with spontaneous Lorentz violation

    International Nuclear Information System (INIS)

    Bluhm, Robert; Gagne, Nolan L.; Potting, Robertus; Vrublevskis, Arturs

    2008-01-01

    Vector theories with spontaneous Lorentz violation, known as bumblebee models, are examined in flat spacetime using a Hamiltonian constraint analysis. In some of these models, Nambu-Goldstone modes appear with properties similar to photons in electromagnetism. However, depending on the form of the theory, additional modes and constraints can appear that have no counterparts in electromagnetism. An examination of these constraints and additional degrees of freedom, including their nonlinear effects, is made for a variety of models with different kinetic and potential terms, and the results are compared with electromagnetism. The Hamiltonian constraint analysis also permits an investigation of the stability of these models. For certain bumblebee theories with a timelike vector, suitable restrictions of the initial-value solutions are identified that yield ghost-free models with a positive Hamiltonian. In each case, the restricted phase space is found to match that of electromagnetism in a nonlinear gauge

  17. Automated constraint placement to maintain pile shape

    KAUST Repository

    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.

  18. Constraint Embedding Technique for Multibody System Dynamics

    Science.gov (United States)

    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

  19. Externalized ileocolic anastomosis: case report.

    Science.gov (United States)

    Simcock, James; Kuntz, Charles A; Newman, Raquel

    2010-01-01

    A 6-year-old, spayed female Labrador retriever was presented 48 hours after an intestinal resection and anastomosis for management of a small intestinal foreign body. Abdominal ultrasound confirmed the presence of peritoneal effusion. Cytology of fluid collected by abdominocentesis revealed a large number of degenerate neutrophils with intracellular cocci. A diagnosis of septic peritonitis was made, presumably because of dehiscence of the anastomosis. Upon repeat exploratory celiotomy, the intestinal anastomosis (located 4 cm orad to the cecum) was found to be leaking intestinal contents into the abdomen. The distal ileum, cecum, and proximal colon were resected. An end-to-end, ileocolic anastomosis was performed and subsequently exteriorized into the subcutaneous space via a paramedian incision through the abdominal wall. The anastomosis was inspected daily for 4 days before it was returned to the abdomen and the subcutaneous defect was closed. Serial cytology of the peritoneal fluid, which was performed during this 4-day postoperative period, confirmed progressive resolution of peritonitis. The dog was discharged from the hospital 2 days following return of the anastomosis into the abdomen. Externalized intestinal anastomosis is used with good success in human medicine for repair of colonic injuries. In this case, externalization of the anastomosis permitted healing of the intestinal anastomosis in an environment isolated from the detrimental effects created by septic peritonitis. In addition, direct visualization of the anastomosis allowed assessment of healing. To our knowledge, this procedure has not been previously reported in companion animals.

  20. L∞ Variational Problems with Running Costs and Constraints

    International Nuclear Information System (INIS)

    Aronsson, G.; Barron, E. N.

    2012-01-01

    Various approaches are used to derive the Aronsson–Euler equations for L ∞ calculus of variations problems with constraints. The problems considered involve holonomic, nonholonomic, isoperimetric, and isosupremic constraints on the minimizer. In addition, we derive the Aronsson–Euler equation for the basic L ∞ problem with a running cost and then consider properties of an absolute minimizer. Many open problems are introduced for further study.

  1. Decentralized systems with design constraints

    CERN Document Server

    Mahmoud, Magdi S

    2014-01-01

    This volume provides a rigorous examination of the analysis, stability and control of large-scale systems, and addresses the difficulties that arise because of dimensionality, information structure constraints, parametric uncertainty and time-delays.

  2. Machine tongues. X. Constraint languages

    Energy Technology Data Exchange (ETDEWEB)

    Levitt, D.

    Constraint languages and programming environments will help the designer produce a lucid description of a problem domain, and then of particular situations and problems in it. Early versions of these languages were given descriptions of real world domain constraints, like the operation of electrical and mechanical parts. More recently, the author has automated a vocabulary for describing musical jazz phrases, using constraint language as a jazz improviser. General constraint languages will handle all of these domains. Once the model is in place, the system will connect built-in code fragments and algorithms to answer questions about situations; that is, to help solve problems. Bugs will surface not in code, but in designs themselves. 15 references.

  3. An Introduction to 'Creativity Constraints'

    DEFF Research Database (Denmark)

    Onarheim, Balder; Biskjaer, Michael Mose

    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 no overall conceptual framing or shared terminology. This lack of unity hinders overt opportunities for cross-disciplinary interchange. We argue that an improved understanding of constraints in creativity holds a promising potential for advancements in creativity research across domains and disciplines. Here......, 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...

  4. An Introduction to 'Creativity Constraints'

    DEFF Research Database (Denmark)

    Onarheim, Balder; Biskjær, Michael Mose

    2013-01-01

    to no overall conceptual framing or shared terminology. This lack of unity hinders overt opportunities for cross-disciplinary interchange. We argue that an improved understanding of constraints in creativity holds a promising potential for advancements in creativity research across domains and disciplines. Here...... and sub-concepts, including ‘late’, ‘self-imposed’, and ‘continua of creativity constraints’, to inform future cross-disciplinary work on creativity constraints....

  5. External split field generator

    Science.gov (United States)

    Thundat, Thomas George [Knoxville, TN; Van Neste, Charles W [Kingston, TN; Vass, Arpad Alexander [Oak Ridge, TN

    2012-02-21

    A generator includes a coil disposed about a core. A first stationary magnetic field source may be disposed on a first end portion of the core and a second stationary magnetic field source may be disposed on a second end portion of core. The first and second stationary magnetic field sources apply a stationary magnetic field to the coil. An external magnetic field source may be disposed outside the coil to apply a moving magnetic field to the coil. Electrical energy is generated in response to an interaction between the coil, the moving magnetic field, and the stationary magnetic field.

  6. Performance Targets and External Benchmarking

    DEFF Research Database (Denmark)

    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...

  7. PROPAGATION-BASED CONSTRAINT SOLVER IN IMS

    Directory of Open Access Journals (Sweden)

    I.Ol. Blynov

    2012-03-01

    Full Text Available Article compiling the main ideas of creating propagation-based constraint solver, theoretical basis of constraint programming and its implementation in IMS (Insertion Modeling System

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

    International Nuclear Information System (INIS)

    Berry, J.; Holland, M.; Lee, D.

    1995-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Automatic Planning of External Search Engine Optimization

    Directory of Open Access Journals (Sweden)

    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.

  11. KEUNTUNGAN PENGGUNAAN EXTERNAL FUNCTION PADA DATABASE POSTGRESQL

    Directory of Open Access Journals (Sweden)

    Nahrun Hartono

    2015-02-01

    Full Text Available Database id a central data for an information system, there were many database system applications that revolve both paid and free. PostgreSQL is one of the free database system and it has the powerful feature, one of the feature that make it different with others sysem is a function features, where the users can make their function by them selves by using spesific programming language, then it can be called return for executed. In this research the writer tries for conducting additional data testing by using INSERT Query and External Function Query on the terminal/command prompt and web browser. From the result of the trial, the research found that the average of time in additional data processing on the terminal/command prompt by using INSERT Query was 185.293 ms and the average of time External Function Query proccess was 129.52 ms, while the average of time in additional data processing on web browser by using INSERT Query was 168.363 ms and External Function Query was 145.64 ms. There was a difference both of the query, but the important thing and should be noted that external function is a command was defined by stand alone by the user, this matter lets the user to determine a specify command that they need.

  12. Combined constraints on holographic bosonic technicolor

    International Nuclear Information System (INIS)

    Carone, Christopher D.; Primulando, Reinard

    2010-01-01

    We consider a model of strong electroweak symmetry breaking in which the expectation value of an additional, possibly composite, scalar field is responsible for the generation of fermion masses. The dynamics of the strongly coupled sector is defined and studied via its holographic dual, and does not correspond to a simple, scaled-up version of QCD. We consider the bounds from perturbative unitarity, the S parameter, and the mass of the Higgs-like scalar. We show that the combination of these constraints leaves a relatively limited region of parameter space viable, and suggests the qualitative features of the model that might be probed at the LHC.

  13. Using the Theory of Constraints for Effective Supply Chain Management

    Directory of Open Access Journals (Sweden)

    Archie Lockhamy III

    1999-08-01

    Full Text Available This article provides methodology and guidelines for employing a 'constraint-based approach for effective supply chain management. The article explores the shortcomings of using a traditional supply chain management as well as an Activity Based Management (ABM approach in the managing of supply chains. In addition, the article introduces a supply chain management methodology based on achieving a global optimum for the entire chain. Examples are provided on how constraint-based techniques are currently being applied to the management of certain subsets of the supply chain. Guidelines are presented for managing supply chains using a constraint-based approach. Finally, the article ends with the discussion of the implications regarding the use of a constraint-based approach to the management of supply chains along with the need for future research in this area.

  14. Instabilities constraint and relativistic mean field parametrization

    International Nuclear Information System (INIS)

    Sulaksono, A.; Kasmudin; Buervenich, T.J.; Reinhard, P.-G.; Maruhn, J.A.

    2011-01-01

    Two parameter sets (Set 1 and Set 2) of the standard relativistic mean field (RMF) model plus additional vector isoscalar nonlinear term, which are constrained by a set of criteria 20 determined by symmetric nuclear matter stabilities at high densities due to longitudinal and transversal particle–hole excitation modes are investigated. In the latter parameter set, δ meson and isoscalar as well as isovector tensor contributions are included. The effects in selected finite nuclei and nuclear matter properties predicted by both parameter sets are systematically studied and compared with the ones predicted by well-known RMF parameter sets. The vector isoscalar nonlinear term addition and instability constraints have reasonably good effects in the high-density properties of the isoscalar sector of nuclear matter and certain finite nuclei properties. However, even though the δ meson and isovector tensor are included, the incompatibility with the constraints from some experimental data in certain nuclear properties at saturation point and the excessive stiffness of the isovector nuclear matter equation of state at high densities as well as the incorrect isotonic trend in binding the energies of finite nuclei are still encountered. It is shown that the problem may be remedied if we introduce additional nonlinear terms not only in the isovector but also in the isoscalar vectors. (author)

  15. Notes on Timed Concurrent Constraint Programming

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Valencia, Frank D.

    2004-01-01

    A constraint is a piece of (partial) information on the values of the variables of a system. Concurrent constraint programming (ccp) is a model of concurrency in which agents (also called processes) interact by telling and asking information (constraints) to and from a shared store (a constraint...

  16. Internalizing Externalities through Payments for Environmental Services

    Directory of Open Access Journals (Sweden)

    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

  17. Constraint programming and decision making

    CERN Document Server

    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...

  18. Aggregating energy flexibilities under constraints

    DEFF Research Database (Denmark)

    Valsomatzis, Emmanouil; Pedersen, Torben Bach; Abello, Alberto

    2016-01-01

    The flexibility of individual energy prosumers (producers and/or consumers) has drawn a lot of attention in recent years. Aggregation of such flexibilities provides prosumers with the opportunity to directly participate in the energy market and at the same time reduces the complexity of scheduling...... and amount dimensions. We define the problem of aggregating FOs taking into account grid power constraints. We also propose two constraint-based aggregation techniques that efficiently aggregate FOs while retaining flexibility. We show through a comprehensive evaluation that our techniques, in contrast...

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

    DEFF Research Database (Denmark)

    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 assessment...... are identified, based on results of earlier studies and some identified of specific relevance for Denmark. Importance is attached to the quantification of impacts for each of the three fuel cycles and to monetisation of the externalities....

  20. Planck constraints on holographic dark energy

    International Nuclear Information System (INIS)

    Li, Miao; Zhang, Zhenhui; Li, Xiao-Dong; Ma, Yin-Zhe; Zhang, Xin

    2013-01-01

    We perform a detailed investigation on the cosmological constraints on the holographic dark energy (HDE) model by using the Plank data. We find that HDE can provide a good fit to the Plank high-l (l ∼> 40) temperature power spectrum, while the discrepancy at l ≅ 20-40 found in the ΛCDM model remains unsolved in the HDE model. The Plank data alone can lead to strong and reliable constraint on the HDE parameter c. At the 68% confidence level (CL), we obtain c = 0.508 ± 0.207 with Plank+WP+lensing, favoring the present phantom behavior of HDE at the more than 2σ CL. By combining Plank+WP with the external astrophysical data sets, i.e. the BAO measurements from 6dFGS+SDSS DR7(R)+BOSS DR9, the direct Hubble constant measurement result (H 0 = 73.8 ± 2.4 kms −1 Mpc −1 ) from the HST, the SNLS3 supernovae data set, and Union2.1 supernovae data set, we get the 68% CL constraint results c = 0.484 ± 0.070, 0.474 ± 0.049, 0.594 ± 0.051, and 0.642 ± 0.066, respectively. The constraints can be improved by 2%-15% if we further add the Plank lensing data into the analysis. Compared with the WMAP-9 results, the Plank results reduce the error by 30%-60%, and prefer a phantom-like HDE at higher significant level. We also investigate the tension between different data sets. We find no evident tension when we combine Plank data with BAO and HST. Especially, we find that the strong correlation between Ω m h 3 and dark energy parameters is helpful in relieving the tension between the Plank and HST measurements. The residual value of χ 2 Plank+WP+HST −χ 2 Plank+WP is 7.8 in the ΛCDM model, and is reduced to 1.0 or 0.3 if we switch the dark energy to w model or the holographic model. When we introduce supernovae data sets into the analysis, some tension appears. We find that the SNLS3 data set is in tension with all other data sets; for example, for the Plank+WP, WMAP-9 and BAO+HST, the corresponding Δχ 2 is equal to 6.4, 3.5 and 4.1, respectively. As a comparison

  1. Sterile neutrino constraints from cosmology

    DEFF Research Database (Denmark)

    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....

  2. Constraint Programming versus Mathematical Programming

    DEFF Research Database (Denmark)

    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. Conjoined Constraints and Phonological Acquisition

    Directory of Open Access Journals (Sweden)

    Giovana Bonilha

    2003-12-01

    Full Text Available 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.

  4. Constraints to increased sludge utilization

    International Nuclear Information System (INIS)

    Pound, C.E.; Bory, L.D.

    1979-01-01

    The management and disposition of municipal sewage sludge is a growing problem as secondary treatment plants are completed to meet Clean Water Act standards. The prohibition of ocean dumping, the increased cost and difficulty to secure and operate sludge landfills, and the high energy costs of dewatering and incineration should all contribute to an increase in land application. However, land application and other beneficial use alternatives, such as give away/sale, account for only 20% of the 12 m/day tons of sludge produced nationally. This result can in part be attributed to public health, institutional, and legal constraints on implementing land application systems. Public health constraints include contaminants in sludge which may pose a risk to human health. Much current controversy about the safety of applying sludge to agricultural land on which food chain crops are grown focuses on heavy metals, especially cadmium. But proposed federal and state regulation of cadmium concentrations in sludge, at levels where human health risk has not been demonstrated, may limit utilization by land application. State operating rules and other administrative controls over sludge application are among the institutional constraints. Since land is an essential element in a land application system, securing adequate and suitable land involves legal constraints. Involuntary acquisition and zoning procedures can delay and frustrate land application programs. Securing indemnity insurance for possible damage to land to which sludge is applied has also been an obstacle to implementation of utilization programs

  5. Financial Constraints: Explaining Your Position.

    Science.gov (United States)

    Cargill, Jennifer

    1988-01-01

    Discusses the importance of educating library patrons about the library's finances and the impact of budget constraints and the escalating cost of serials on materials acquisition. Steps that can be taken in educating patrons by interpreting and publicizing financial information are suggested. (MES)

  6. Observational constraints on cluster evolution

    NARCIS (Netherlands)

    Larsen, S.S.

    2008-01-01

    Current observational constraints on the dynamical evolution of star clusters are reviewed. Theory and observations now agree nicely on the mass dependency and time scales for disruption of young star clusters in galactic disks, but many problems still await resolution. The origin of the mass

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

    Science.gov (United States)

    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...

  8. Multibody motion in implicitly constrained director format with links via explicit constraints

    DEFF Research Database (Denmark)

    Nielsen, Martin Bjerre; Krenk, Steen

    2013-01-01

    with the presence of kinematic joints for linking bodies together. The equations of motion are derived from Hamilton’s equations with an augmented Hamiltonian in which internal and external constraints initially are included via Lagrange multipliers. Subsequently the Lagrange multipliers associated with internal...

  9. Study of low energy thermal constraints for a copper-plated niobium structure carried out by thermal projection; Etude des contraintes thermiques a basse temperature d'une structure en niobium avec un revetement de cuivre realise par projection thermique

    Energy Technology Data Exchange (ETDEWEB)

    Gassot, H.; Durante, M. [Institut de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France); Thiebault, A.; Vernay, E. [Laboratoire de l' Accelerateur Lineaire, 91 - Orsay (France)

    1999-06-01

    In the framework of T.T.F. (Tesla Test Facility), the international collaboration on research and development of superconducting cavities, a study of a new method of manufacturing cavities was launched, which consists in deposing a metal (copper) or an alloy by thermal projection on niobium cavities in order to stiffen them. Analytical and numerical calculations showed that when cooled this bi-material cavities behave very differently incomparison with classical pure niobium cavities and strong thermal constraints do occur in niobium as well as in copper. These strong constraints may have important consequences upon the functioning of superconducting cavities. In addition these constraints may induce in time cracks in materials and interfaces. In this paper an experiment for measuring constraints at the temperature of cavity operation, i.e., at the liquid helium temperature, is proposed in order to compare the measured constraints with the calculated constraints. The sample studied has a cylindrical shape, rather representative for the geometrical shape of cavities, but easier to handle than a prototype cavity. The experimental approach consists in carrying out two deformation measurements. The first one, is done on single material sample (niobium and copper) to establish the laws of compensation of the constraint gauges as a function of temperature. The other measurement establishes the global deformations of a bi-metallic tube (Nb-Cu) when the interior surface (niobium) and the external surface (porous copper) of the tube are cooled. From these deformation data the thermal constraints of the bi-metallic tube at low temperature have been derived. The implementation of the entire setup of the methods of measuring the constraints at low temperature constitutes a new development in the field of superconducting cavities. The experiments have also indicated certain further developments which should be achieved if the plastic deformations induced by the freezing regime

  10. External Debt and Economic Growth in Tunisia

    OpenAIRE

    Nasfi Fkili Wahiba

    2014-01-01

    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 impac...

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

    DEFF Research Database (Denmark)

    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...

  12. Managing Constraint Generators in Retail Design Processes

    DEFF Research Database (Denmark)

    Münster, Mia Borch; Haug, Anders

    case studies of fashion store design projects, the present paper addresses this gap. The and six case studies of fashion store design projects, the present paper sheds light on the types of constraints generated by the relevant constraint generators. The paper shows that in the cases studied......, the influence of the constraints generated by these constraint generators decreased during the design process except for supplier-generated constraints, which increased in the final stages of the design process. The paper argues that a thorough design preparation phase would be beneficial, and that constraints...

  13. Creativity from Constraints in Engineering Design

    DEFF Research Database (Denmark)

    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: blackboxing...

  14. Economic growth constraints in Vietnam: A study using the growth diagnostic approach

    Directory of Open Access Journals (Sweden)

    Nguyen Duc Thanh

    2016-04-01

    Full Text Available Recent studies have clearly pointed out a decreasing trend of Vietnam’s economic growth in the short and the medium terms. This paper presents a study applying the growth diagnostic method for Vietnam to determine growth constrains. The binding growth constrains of Vietnam are found to include a poor business environment; an underdeveloped infrastructure, especially the transportation network market; failures related to information externalities, learning externalities and coordination failures. Notably, the energy infrastructure could be a vital constraint in a near future, but is not a binding constraint at present. The inefficiency of financial intermediaries and the government’s over-investment could become a binding constraint when the economy returns to its high growth path.

  15. Retrofitting Systems for External Walls

    DEFF Research Database (Denmark)

    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 d....... The different systems are evaluated using 5 different types of existing walls....

  16. External coating of colonic anastomoses

    DEFF Research Database (Denmark)

    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...

  17. External benefits of natural environments

    Science.gov (United States)

    Larry W. Tombaugh

    1971-01-01

    Existing methods of assessing economic benefits arising from certain physical environments left in a relatively natural condition do not include estimates of external benefits. Existence value is one such external benefit that accrues to individuals who have no intention of ever visiting the area in question. A partial measure of the existence value of National Parks...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  19. BFFT quantization with nonlinear constraints

    Energy Technology Data Exchange (ETDEWEB)

    Barcelos-Neto, J. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, RJ 21945-970, Caixa Postal 68528 (Brazil)

    1997-02-01

    We consider the method due to Batalin, Fradkin, Fradkina, and Tyutin (BFFT) that makes the conversion of second-class constraints into first-class ones for the case of nonlinear theories. We first present a general analysis of an attempt to simplify the method, showing the conditions that must be satisfied in order to have first-class constraints for nonlinear theories that are linear in the auxiliary variables. There are cases where this simplification cannot be done and the full BFFT method has to be used. However, in the way the method is formulated, we show with details that it is not practicable to be done. Finally, we speculate on a solution for these problems. {copyright} {ital 1997} {ital The American Physical Society}

  20. A compendium of chameleon constraints

    Energy Technology Data Exchange (ETDEWEB)

    Burrage, Clare [School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD (United Kingdom); Sakstein, Jeremy, E-mail: clare.burrage@nottingham.ac.uk, E-mail: jeremy.sakstein@port.ac.uk [Center for Particle Cosmology, Department of Physics and Astronomy, University of Pennsylvania, 209 S. 33rd St., Philadelphia, PA 19104 (United States)

    2016-11-01

    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.

  1. A compendium of chameleon constraints

    International Nuclear Information System (INIS)

    Burrage, Clare; Sakstein, Jeremy

    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.

  2. Self-Imposed Creativity Constraints

    DEFF Research Database (Denmark)

    Biskjaer, Michael Mose

    2013-01-01

    and high concept awareness characterizing the humanities’ general mode of inquiry; (b) expertise in formulating new ‘big’ exploratory and unifying questions, which are waning in creativity research; and (c) greater versatility in the use of empirical data material, since the analytical, speculative...... increasingly fragmented and in need of new ‘big’ unifying questions. Hence the designation of the dissertation’s research approach. The four papers serve a dual purpose. They are contributions in their own right, and they provide partial answers to the overall research question. In this respect, the concept...... of the current dispersed studies on constraints in creativity, spanning psychology, engineering, philosophy, design, and aesthetics. (2) Definitions, concepts, and models of self-imposed creativity constraints for analytical application within and across creative domains, including the 6i model for demonstrating...

  3. Planck intermediate results: XLVII. Planck constraints on reionization history

    DEFF Research Database (Denmark)

    Adam, R.; Aghanim, N.; Ashdown, M.

    2016-01-01

    additional information from the high-resolution Atacama Cosmology Telescope and South Pole Telescope experiments. The average redshift at which reionization occurs is found to lie between z = 7.8 and 8.8, depending on the model of reionization adopted. Using kSZ constraints and a redshift...

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Managing Restaurant Tables using Constraints

    Science.gov (United States)

    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.

  6. Profit Taxation and Finance Constraints

    OpenAIRE

    Christian Keuschnigg; Evelyn Ribi

    2010-01-01

    In the absence of financing frictions, profit taxes reduce investment by their effect on the user cost of capital. With finance constraints due to moral hazard, investment becomes sensitive to cash-flow and own equity of firms. The impact of taxes changes fundamentally. Taxes reduce investment because they erode cash flow and, thereby, a firm's pledgeable income available for repayment to outside investors, and not because they reduce the user cost of capital. We propose a corporate finance m...

  7. Updating neutrino magnetic moment constraints

    Directory of Open Access Journals (Sweden)

    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.

  8. Analysis of Space Tourism Constraints

    Science.gov (United States)

    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.

  9. Infrared Constraint on Ultraviolet Theories

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Relaxations of semiring constraint satisfaction problems

    CSIR Research Space (South Africa)

    Leenen, L

    2007-03-01

    Full Text Available The Semiring Constraint Satisfaction Problem (SCSP) framework is a popular approach for the representation of partial constraint satisfaction problems. In this framework preferences can be associated with tuples of values of the variable domains...

  11. Movement constraints on interpersonal coordination and communication.

    Science.gov (United States)

    Tolston, Michael T; Shockley, Kevin; Riley, Michael A; Richardson, Michael J

    2014-10-01

    The present study investigated how constraining movement affects interpersonal coordination and joint cognitive performance. Pairs of participants worked cooperatively to solve picture-puzzle tasks in which they conversed to identify differences between pictures in 3 degree-of-constraint conditions: both participants were free to move their hands (free-free; FF); both participants' hands were restrained (restrained-restrained; RR); and the hands of 1 participant were free while the hands of the other participant were restrained (free-restrained; FR). Eye tracking data were collected, and movement was measured at the waist, hand, and head. Data were analyzed using Cross-Recurrence Quantification Analysis (CRQ). Postural sway coordination, gaze coordination, and task performance were predicted to be highest in FF, followed by RR, and then by FR. Results showed the asymmetric FR condition generally exhibited lesser degrees of coordination than the symmetric Conditions FF and RR, and that the patterning of coordination in the symmetric conditions varied across the measured body segments. These results demonstrate that movement restraints affect not only interpersonal postural coordination, but also joint attention. Additionally, significant positive relationships were found between task performance and total amount of anterior-posterior movement measured at the head, hand and waist; number of utterances; and number of differences pairs found in the puzzles. These findings indicate a relationship between movement and task performance consistent with the hypotheses that both interpersonal coordination and cognitive performance are sensitive to local action constraints.

  12. Experimental constraint on quark electric dipole moments

    Science.gov (United States)

    Liu, Tianbo; Zhao, Zhiwen; Gao, Haiyan

    2018-04-01

    The electric dipole moments (EDMs) of nucleons are sensitive probes of additional C P violation sources beyond the standard model to account for the baryon number asymmetry of the universe. As a fundamental quantity of the nucleon structure, tensor charge is also a bridge that relates nucleon EDMs to quark EDMs. With a combination of nucleon EDM measurements and tensor charge extractions, we investigate the experimental constraint on quark EDMs, and its sensitivity to C P violation sources from new physics beyond the electroweak scale. We obtain the current limits on quark EDMs as 1.27 ×10-24 e .cm for the up quark and 1.17 ×10-24 e .cm for the down quark at the scale of 4 GeV2 . We also study the impact of future nucleon EDM and tensor charge measurements, and show that upcoming new experiments will improve the constraint on quark EDMs by about 3 orders of magnitude leading to a much more sensitive probe of new physics models.

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Guidance for External Events Analysis

    International Nuclear Information System (INIS)

    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

  16. Ant colony optimization and constraint programming

    CERN Document Server

    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

  17. traumatismes externes du larynx external laryngeal trauma of larynx

    African Journals Online (AJOL)

    Introduction : Le traumatisme externe du larynx est relativement rare mais expose à un risque vital immédiat. En l'absence de dia- gnostic et de prise en charge rapide il expose à des séquelles fonctionnelles. Le but de ce travail est de rappeler la présentation clinique des traumatismes externes du larynx et d'étayer notre ...

  18. Bin-packing problems with load balancing and stability constraints

    DEFF Research Database (Denmark)

    Trivella, Alessio; Pisinger, David

    -packing and load balancing of items. The problem has only been considered in the literature in simplified versions, e.g. balancing a single bin or introducing a feasible region for the barycenter. In section 3 we generalize the problem to handle cargo stability and weight constraints....... realistic constraints related to e.g. load balancing, cargo stability and weight limits, in the multi-dimensional BPP. The BPP poses additional challenges compared to the CLP due to the supplementary objective of minimizing the number of bins. In particular, in section 2 we discuss how to integrate bin...

  19. Constraints on CP violating four-fermion interactions

    International Nuclear Information System (INIS)

    He, X.G.; McKellar, B.

    1996-04-01

    It has been shown that CP violating electron-nucleon and nucleon-nucleon interactions can induce atomic electric dipole moments and are therefore constrained from experimental data. We show that using the experimental upper bounds on neutron and electron electric dipole moments, one can also obtain constraints, in some cases better ones, on these interactions. In addition stringent constraints can also be obtained for muon-quark and tauon-quark four-fermion CP violating interactions, which cannot be constrained from atomic electric dipole moment experiments. 12 refs., 2 tabs., 1 fig

  20. Aeroelastic Tailoring of Transport Wings Including Transonic Flutter Constraints

    Science.gov (United States)

    Stanford, Bret K.; Wieseman, Carol D.; Jutte, Christine V.

    2015-01-01

    Several minimum-mass optimization problems are solved to evaluate the effectiveness of a variety of novel tailoring schemes for subsonic transport wings. Aeroelastic stress and panel buckling constraints are imposed across several trimmed static maneuver loads, in addition to a transonic flutter margin constraint, captured with aerodynamic influence coefficient-based tools. Tailoring with metallic thickness variations, functionally graded materials, balanced or unbalanced composite laminates, curvilinear tow steering, and distributed trailing edge control effectors are all found to provide reductions in structural wing mass with varying degrees of success. The question as to whether this wing mass reduction will offset the increased manufacturing cost is left unresolved for each case.

  1. Normal tissue tolerance to external beam radiation therapy: The mandible

    International Nuclear Information System (INIS)

    Berger, A.; Bensadoun, R.J.

    2010-01-01

    Describing dose constraints for organs at risk in external beam radiotherapy is a key-point in order to maximize the therapeutic ratio. In head and neck irradiation, mandible is frequently exposed to ionising radiation-related complications. Those complications will be exposed after a short description of anatomical and physiopathological aspects. A literature search was performed using the Pubmed-Medline database, with following keywords (Osteoradionecrosis, Radiotherapy, Mandible, Toxicity, Organ at risk, Trismus). Incidence and dose constraints will be reported. The incidence of osteoradionecrosis decreased since the 1990, but it remains a dreaded late complication of head and neck cancer radiotherapy. It essentially occurs with cumulative doses of 66 Gy on the mandible (standard fractionation) applied to a significant volume. Respecting oral care is crucial to avoid this kind of complication. The respect of the dose-constraint described should not lead to under treat tumor bed in a curative intent. Trismus related to ionising radiation is poorly described. Literature data cannot lead to describe precise dose constraints. (authors)

  2. External effects in Swiss hydropower

    International Nuclear Information System (INIS)

    Hauenstein, W.; Bonvin, J.; Vouillamoz, J.

    1999-01-01

    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

  3. A general treatment of dynamic integrity constraints

    NARCIS (Netherlands)

    de Brock, EO

    This paper introduces a general, set-theoretic model for expressing dynamic integrity constraints, i.e., integrity constraints on the state changes that are allowed in a given state space. In a managerial context, such dynamic integrity constraints can be seen as representations of "real world"

  4. Constraints and Strategies for Improving Agricultural Intervention ...

    African Journals Online (AJOL)

    Poverty was the major constraint perceived by farmers (mean = 3.89), while facilitators perceived both high cost of farm inputs and lack of credit facilities as the most serious constraint (mean = 3.38 each). Both farmers and facilitators shared similar opinion on twenty identified constraints and have significant differences in ...

  5. Elimination of Constraints from Feature Trees

    NARCIS (Netherlands)

    van den Broek, P.M.; Galvao, I.; Noppen, J.A.R.

    2008-01-01

    We present an algorithm which eliminates constraints from a feature model whose feature diagram is a tree and whose constraints are "requires" or "excludes" constraints. The algorithm constructs a feature tree which has the same semantics as the original feature model. The computational complexity

  6. Learning and Parallelization Boost Constraint Search

    Science.gov (United States)

    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…

  7. Optimal control of linear, stochastic systems with state and input constraints

    NARCIS (Netherlands)

    Batina, Ivo; Stoorvogel, Antonie Arij; Weiland, Siep

    2002-01-01

    In this paper we extend the work presented in our previous papers (2001) where we considered optimal control of a linear, discrete time system subject to input constraints and stochastic disturbances. Here we basically look at the same problem but we additionally consider state constraints. We

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

    DEFF Research Database (Denmark)

    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......) with an additional constraint on the maximum allowable amount mass....

  9. External imaging of human atherosclerosis

    International Nuclear Information System (INIS)

    Lees, R.S.; Lees, A.M.

    1986-01-01

    For external imaging of arteriosclerotic lesions in blood vessels, low-density lipoproteins labeled by 99 Tc were employed, instead of radiolabelled blood platelets. The results suggest that the ability to be imaged correlates with lesion activity. (Auth.)

  10. Comments on the nilpotent constraint of the goldstino superfield

    CERN Document Server

    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\

  11. A Constraint-Based Understanding of Design Spaces

    DEFF Research Database (Denmark)

    Biskjaer, Michael Mose; Dalsgaard, Peter; Halskov, Kim

    2014-01-01

    This paper suggests a framework for understanding and manoeuvring design spaces based on insights from research into creativity constraints. We define the design space as a conceptual space, which in addition to being co-constituted, explored and developed by the designer encompasses the creativity...... constraints governing the design process. While design spaces can be highly complex, our constraint-based understanding enables us to argue for the benefits of a systematic approach to mapping and manipulating aspects of the design space. We discuss how designers by means of a simple representation, a design...... space schema, can identify the properties of the prospective product that s/he can form. Through a case study, we show how design space schemas can support designers in various ways, including gaining an overview of the design process, documenting it, reflecting on it, and developing design concepts...

  12. Automatic Constraint Detection for 2D Layout Regularization.

    Science.gov (United States)

    Jiang, Haiyong; Nan, Liangliang; Yan, Dong-Ming; Dong, Weiming; Zhang, Xiaopeng; Wonka, Peter

    2016-08-01

    In this paper, we address the problem of constraint detection for layout regularization. The layout we consider is a set of two-dimensional elements where each element is represented by its bounding box. Layout regularization is important in digitizing plans or images, such as floor plans and facade images, and in 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 layout regularization as a quadratic programming problem. In addition, we propose a novel optimization algorithm that automatically detects constraints. We evaluate the proposed framework using a variety of input layouts from different applications. Our results demonstrate that our method has superior performance to the state of the art.

  13. Procedural Design of Exterior Lighting for Buildings with Complex Constraints

    KAUST Repository

    Schwarz, Michael

    2014-10-01

    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.

  14. Automatic Constraint Detection for 2D Layout Regularization

    KAUST Repository

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    International Nuclear Information System (INIS)

    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 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. Optimal Population and Exhaustible Resource Constraints.

    Science.gov (United States)

    Lawson, Nicholas; Spears, Dean

    2018-01-01

    A large literature considers the optimal size and growth rate of the human population, trading off the utility value of additional people with the costs of a larger population. In this literature, an important parameter is the social weight placed on population size; a standard result is that a planner with a larger weight on population chooses larger population levels and growth rates. We demonstrate that this result is conditionally overturned when an exhaustible resource constraint is introduced: if the discount rate is small enough, the optimal population today decreases with the welfare weight on population size. That is, a more total-utilitarian social planner could prefer a smaller population today than a more average-utilitarian social planner. We also present a numerical illustration applied to the case of climate change, where we show that under plausible real-world parameter values, our result matters for the direction and magnitude of optimal population policy.

  18. Observational constraints on black hole accretion disks

    Science.gov (United States)

    Liang, Edison P.

    1994-01-01

    We review the empirical constraints on accretion disk models of stellar-mass black holes based on recent multiwavelength observational results. In addition to time-averaged emission spectra, the time evolutions of the intensity and spectrum provide critical information about the structure, stability, and dynamics of the disk. Using the basic thermal Keplerian disk paradigm, we consider in particular generalizations of the standard optically thin disk models needed to accommodate the extremely rich variety of dynamical phenomena exhibited by black hole candidates ranging from flares of electron-positron annihilations and quasiperiodic oscillations in the X-ray intensity to X-ray novae activity. These in turn provide probes of the disk structure and global geometry. The goal is to construct a single unified framework to interpret a large variety of black hole phenomena. This paper will concentrate on the interface between basic theory and observational data modeling.

  19. A global approach to kinematic path planning to robots with holonomic and nonholonomic constraints

    Science.gov (United States)

    Divelbiss, Adam; Seereeram, Sanjeev; Wen, John T.

    1993-12-01

    Robots in applications may be subject to holonomic or nonholonomic constraints. Examples of holonomic constraints include a manipulator constrained through the contact with the environment, e.g., inserting a part, turning a crank, etc., and multiple manipulators constrained through a common payload. Examples of nonholonomic constraints include no-slip constraints on mobile robot wheels, local normal rotation constraints for soft finger and rolling contacts in grasping, and conservation of angular momentum of in-orbit space robots. The above examples all involve equality constraints; in applications, there are usually additional inequality constraints such as robot joint limits, self collision and environment collision avoidance constraints, steering angle constraints in mobile robots, etc. The problem of finding a kinematically feasible path that satisfies a given set of holonomic and nonholonomic constraints, of both equality and inequality types is addressed. The path planning problem is first posed as a finite time nonlinear control problem. This problem is subsequently transformed to a static root finding problem in an augmented space which can then be iteratively solved. The algorithm has shown promising results in planning feasible paths for redundant arms satisfying Cartesian path following and goal endpoint specifications, and mobile vehicles with multiple trailers. In contrast to local approaches, this algorithm is less prone to problems such as singularities and local minima.

  20. External meeting: Geneva University

    CERN Multimedia

    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...

  1. External meeting: Geneva University

    CERN Multimedia

    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....

  2. Vehicle Fuel-Efficiency Choices, Emission Externalities, and Urban Sprawl

    DEFF Research Database (Denmark)

    Kim, Jinwon

    by the city residents. We first establish the well-known result that congestion externality is the source of market failure associated with excessive urban sprawl. We then claim that vehicle emissions are an additional source of market failure, which also leads to excessive urban sprawl. The source......This paper shows that the city where both congestion externalities and externalities from greenhouse gas emissions are corrected by efficient policies is more compact than the laissez-faire equilibrium city. Motivated by recent empirical studies showing a positive relationship between population...... of excessive sprawl arising from emission externalities is the uses of larger and less-fuel efficient vehicles by suburban residents, which is different from that of congestion externalities. We also analyze the effect of the Corporate Average Fuel Efficiency (CAFE) regulation on the urban spatial structure....

  3. External doses from radioactive fallout. Dosimetry and levels

    International Nuclear Information System (INIS)

    Woehni, T.

    1995-01-01

    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 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

  4. External doses from radioactive fallout. Dosimetry and levels

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Experimental Constraints on Core Composition

    Science.gov (United States)

    Li, J.; Fei, Y.

    2003-12-01

    complex structure of the Earth's interior, seismic investigations require extensive data coverage, sophisticated modeling and efficient data analytical methods. Deciphering geochemical core signatures carried by mantle plumes faces similar challenges. In addition, experimental and computational simulations have been hindered by the necessity to approach extreme pressure and temperature conditions prevalent in the core. For these reasons, many fundamental issues concerning the Earth's core remain controversial or poorly understood.Along with steady improvement in observational, experimental, and computational techniques, research interest in the Earth's core has been growing over the last few decades. Issues of current interest include the timing, duration, and mechanism of core formation, the identity and abundance of light elements in the core, the thermal and chemical evolution of the core, the possibility of ongoing radioactive decay in the core, evidence for continuing core-mantle interaction, structure and dynamics of the outer and inner core, and the origin, structure, and evolution of the geomagnetic field. Progress in the study of the Earth's core has been reviewed by a number of researchers with different perspectives (e.g., Stevenson, 1981; Jacobs, 1987; Jeanloz, 1990; Poirier, 1994; Hillgren et al., 2000). The aim of this chapter is to provide an updated summary of our understanding of the composition of the Earth's core, with an emphasis on experimental constraints. Another chapter focusing on cosmochemical and geochemical observations can be found in Chapter 2.15.We will start with a description of experimental and analytical techniques used in the studies of the Earth's core. Following a review of geophysical and geochemical evidence for iron being the most abundant element in the core, we will provide a summary of experimental data on the phase diagram, equation-of-state (EOS), and physical properties of iron and discuss their implications for the core

  6. External proton and Li beams

    International Nuclear Information System (INIS)

    Schuff, Juan A.; Burlon, Alejandro A.; Debray, Mario E.; Kesque, Jose M.; Kreiner, Andres J.; Stoliar, Pablo A.; Naab, Fabian; Ozafran, Mabel J.; Vazquez, Monica E.; Perez de la Hoz, A.; Somacal, Hector; Valda, Alejandro; Canevas, S.; Ruffolo, M.; Tasat, D.R.; Muhlmann, M. C.

    2000-01-01

    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)

  7. Externalities of energy. Swedish implementation of the ExternE methodology

    International Nuclear Information System (INIS)

    Nilsson, Maans; Gullberg, M.

    1998-01-01

    The growing interest for developing economic instruments for efficient environmental policies has opened up a large area of multi-disciplinary research. ExternE is an example of this research, combining disciplines such as engineering, ecology, immunology and economics expertise to create new knowledge about how environmental pressures from energy production affect our nature and society. The ExternE Project aims to identify and, as far as possible quantify the externalities of energy production in Europe. The Stockholm Environment Institute has carried out a preliminary aggregation: -Coal Fuel Cycle: centred around Vaesteraas Kraftvaermeverk, Vaesteraas. This is the largest co-generation plant in Sweden, with four blocks and a maximum co-generation output of 520 MW electricity and 950 MW heat. The analysis is carried out on boiler B4. -Biomass Fuel Cycle: centred around Haendeloeverket, Norrkoeping. This plant predominately burns forestry residues, but a variety of fuels are combusted. Haendeloeverket has an installed capacity of 100 MW electricity and 375 MW heat, in a total of three boilers and two back-pressure turbines. The analysis is carried out on boiler P13. -Hydro Fuel Cycle: Klippens Kraftstation, Storuman. Built in 1990-1994, it is the youngest hydro power station in Sweden. It has been designed and built with significant efforts to account for and protect environmental values. Installed capacity is 28 MW. The environmental impact assessment from the construction of this plant is carried out, but the evaluation is still not finalized. The preliminary aggregation aimed to test whether ExternE results could be used to make estimates for the entire Swedish electricity production system. Hence, national results as well as results from other partner countries in ExternE has been applied

  8. Parallel External Memory Graph Algorithms

    DEFF Research Database (Denmark)

    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....

  9. Creativity from Constraints in Engineering Design

    DEFF Research Database (Denmark)

    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......, removal, introducing and revising. Constraints introduced late in a project contributed to the generation of new solutions to old problems, and existing solutions were creatively adopted to satisfy new constraints. This paper recommends creative constraint-handling strategies, as well as identifying...

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Evolutionary stability for matrix games under time constraints.

    Science.gov (United States)

    Garay, József; Csiszár, Villő; Móri, Tamás F

    2017-02-21

    Game theory focuses on payoffs and typically ignores time constraints that play an important role in evolutionary processes where the repetition of games can depend on the strategies, too. We introduce a matrix game under time constraints, where each pairwise interaction has two consequences: both players receive a payoff and they cannot play the next game for a specified time duration. Thus our model is defined by two matrices: a payoff matrix and an average time duration matrix. Maynard Smith's concept of evolutionary stability is extended to this class of games. We illustrate the effect of time constraints by the well-known prisoner's dilemma game, where additional time constraints can ensure the existence of unique evolutionary stable strategies (ESS), both pure and mixed, or the coexistence of two pure ESS. Our general results may be useful in several fields of biology where evolutionary game theory is applied, principally in ecological games, where time constraints play an inevitable role. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Transition constraints for temporal attributes

    CSIR Research Space (South Africa)

    Ongoma, EAN

    2014-07-01

    Full Text Available with an attribute) changes and the scheduled attribute of occupation becomes active. CASE A is not just a byproduct of inheritance because the values of the attributes change as object migration takes place. Employee Manager access access eID eID DEX ADEX HIVpos... certain value, he is moved to a higher class of tax remittance. 4.3 Logical Implications Logical implications are important to derive new constraints from a set of defined ax- ioms. Given the set of axioms for attribute migration and the set of axioms...

  13. External Costs Related to Power Production Technologies

    DEFF Research Database (Denmark)

    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...

  14. External Tank - The Structure Backbone

    Science.gov (United States)

    Welzyn, Kenneth; Pilet, Jeffrey C.; Diecidue-Conners, Dawn; Worden, Michelle; Guillot, Michelle

    2011-01-01

    The External Tank forms the structural backbone of the Space Shuttle in the launch configuration. Because the tank flies to orbital velocity with the Space Shuttle Orbiter, minimization of weight is mandatory, to maximize payload performance. Choice of lightweight materials both for structure and thermal conditioning was necessary. The tank is large, and unique manufacturing facilities, tooling, handling, and transportation operations were required. Weld processes and tooling evolved with the design as it matured through several block changes, to reduce weight. Non Destructive Evaluation methods were used to assure integrity of welds and thermal protection system materials. The aluminum-lithium alloy was used near the end of the program and weld processes and weld repair techniques had to be refined. Development and implementation of friction stir welding was a substantial technology development incorporated during the Program. Automated thermal protection system application processes were developed for the majority of the tank surface. Material obsolescence was an issue throughout the 40 year program. The final configuration and tank weight enabled international space station assembly in a high inclination orbit allowing international cooperation with the Russian Federal Space Agency. Numerous process controls were implemented to assure product quality, and innovative proof testing was accomplished prior to delivery. Process controls were implemented to assure cleanliness in the production environment, to control contaminants, and to preclude corrosion. Each tank was accepted via rigorous inspections, including non-destructive evaluation techniques, proof testing, and all systems testing. In the post STS-107 era, the project focused on ascent debris risk reduction. This was accomplished via stringent process controls, post flight assessment using substantially improved imagery, and selective redesigns. These efforts were supported with a number of test programs to

  15. Leading multiple teams: average and relative external leadership influences on team empowerment and effectiveness.

    Science.gov (United States)

    Luciano, Margaret M; Mathieu, John E; Ruddy, Thomas M

    2014-03-01

    External leaders continue to be an important source of influence even when teams are empowered, but it is not always clear how they do so. Extending research on structurally empowered teams, we recognize that teams' external leaders are often responsible for multiple teams. We adopt a multilevel approach to model external leader influences at both the team level and the external leader level of analysis. In doing so, we distinguish the influence of general external leader behaviors (i.e., average external leadership) from those that are directed differently toward the teams that they lead (i.e., relative external leadership). Analysis of data collected from 451 individuals, in 101 teams, reporting to 25 external leaders, revealed that both relative and average external leadership related positively to team empowerment. In turn, team empowerment related positively to team performance and member job satisfaction. However, while the indirect effects were all positive, we found that relative external leadership was not directly related to team performance, and average external leadership evidenced a significant negative direct influence. Additionally, relative external leadership exhibited a significant direct positive influence on member job satisfaction as anticipated, whereas average external leadership did not. These findings attest to the value in distinguishing external leaders' behaviors that are exhibited consistently versus differentially across empowered teams. Implications and future directions for the study and management of external leaders overseeing multiple teams are discussed.

  16. Weight Constraints in Neural Networks

    Directory of Open Access Journals (Sweden)

    Subha Fernando

    2012-01-01

    Full Text Available Hebbian plasticity precisely describes how synapses increase their synaptic strengths according to the correlated activities between two neurons; however, it fails to explain how these activities dilute the strength of the same synapses. Recent literature has proposed spike-timing-dependent plasticity and short-term plasticity on multiple dynamic stochastic synapses that can control synaptic excitation and remove many user-defined constraints. Under this hypothesis, a network model was implemented giving more computational power to receptors, and the behavior at a synapse was defined by the collective dynamic activities of stochastic receptors. An experiment was conducted to analyze can spike-timing-dependent plasticity interplay with short-term plasticity to balance the excitation of the Hebbian neurons without weight constraints? If so what underline mechanisms help neurons to maintain such excitation in computational environment? According to our results both plasticity mechanisms work together to balance the excitation of the neural network as our neurons stabilized its weights for Poisson inputs with mean firing rates from 10 Hz to 40 Hz. The behavior generated by the two neurons was similar to the behavior discussed under synaptic redistribution, so that synaptic weights were stabilized while there was a continuous increase of presynaptic probability of release and higher turnover rate of postsynaptic receptors.

  17. Chance-Constrained Guidance With Non-Convex Constraints

    Science.gov (United States)

    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

  18. Constraint-induced sound therapy for sudden sensorineural hearing loss--behavioral and neurophysiological outcomes.

    Science.gov (United States)

    Okamoto, Hidehiko; Fukushima, Munehisa; Teismann, Henning; Lagemann, Lothar; Kitahara, Tadashi; Inohara, Hidenori; Kakigi, Ryusuke; Pantev, Christo

    2014-01-29

    Sudden sensorineural hearing loss is characterized by acute, idiopathic hearing deterioration. We report here the development and evaluation of "constraint-induced sound therapy", which is based on a well-established neuro-rehabilitation approach, and which is characterized by the plugging of the intact ear ("constraint") and the simultaneous, extensive stimulation of the affected ear with music. The sudden sensorineural hearing loss patients who received the constraint-induced sound therapy in addition to the standard corticosteroid therapy showed significantly better recovery of hearing function compared to those who had only received corticosteroid treatments. Additionally, the brain activity obtained in a subgroup of patients suggested that the constraint-induced sound therapy could have prevented maladaptive auditory cortex reorganization. Constraint-induced sound therapy thus appears to be an effective, practical, and safe treatment option for sudden sensorineural hearing loss.

  19. Adaptive laser link reconfiguration using constraint propagation

    Science.gov (United States)

    Crone, M. S.; Julich, P. M.; Cook, L. M.

    1993-01-01

    This paper describes Harris AI research performed on the Adaptive Link Reconfiguration (ALR) study for Rome Lab, and focuses on the application of constraint propagation to the problem of link reconfiguration for the proposed space based Strategic Defense System (SDS) Brilliant Pebbles (BP) communications system. According to the concept of operations at the time of the study, laser communications will exist between BP's and to ground entry points. Long-term links typical of RF transmission will not exist. This study addressed an initial implementation of BP's based on the Global Protection Against Limited Strikes (GPALS) SDI mission. The number of satellites and rings studied was representative of this problem. An orbital dynamics program was used to generate line-of-site data for the modeled architecture. This was input into a discrete event simulation implemented in the Harris developed COnstraint Propagation Expert System (COPES) Shell, developed initially on the Rome Lab BM/C3 study. Using a model of the network and several heuristics, the COPES shell was used to develop the Heuristic Adaptive Link Ordering (HALO) Algorithm to rank and order potential laser links according to probability of communication. A reduced set of links based on this ranking would then be used by a routing algorithm to select the next hop. This paper includes an overview of Constraint Propagation as an Artificial Intelligence technique and its embodiment in the COPES shell. It describes the design and implementation of both the simulation of the GPALS BP network and the HALO algorithm in COPES. This is described using a 59 Data Flow Diagram, State Transition Diagrams, and Structured English PDL. It describes a laser communications model and the heuristics involved in rank-ordering the potential communication links. The generation of simulation data is described along with its interface via COPES to the Harris developed View Net graphical tool for visual analysis of communications

  20. Design Constraints on a Synthetic Metabolism

    Science.gov (United States)

    Bilgin, Tugce; Wagner, Andreas

    2012-01-01

    A metabolism is a complex network of chemical reactions that converts sources of energy and chemical elements into biomass and other molecules. To design a metabolism from scratch and to implement it in a synthetic genome is almost within technological reach. Ideally, a synthetic metabolism should be able to synthesize a desired spectrum of molecules at a high rate, from multiple different nutrients, while using few chemical reactions, and producing little or no waste. Not all of these properties are achievable simultaneously. We here use a recently developed technique to create random metabolic networks with pre-specified properties to quantify trade-offs between these and other properties. We find that for every additional molecule to be synthesized a network needs on average three additional reactions. For every additional carbon source to be utilized, it needs on average two additional reactions. Networks able to synthesize 20 biomass molecules from each of 20 alternative sole carbon sources need to have at least 260 reactions. This number increases to 518 reactions for networks that can synthesize more than 60 molecules from each of 80 carbon sources. The maximally achievable rate of biosynthesis decreases by approximately 5 percent for every additional molecule to be synthesized. Biochemically related molecules can be synthesized at higher rates, because their synthesis produces less waste. Overall, the variables we study can explain 87 percent of variation in network size and 84 percent of the variation in synthesis rate. The constraints we identify prescribe broad boundary conditions that can help to guide synthetic metabolism design. PMID:22768162

  1. Cosmological Parameter Constraints from the Dark Energy Survey Supernova Program Three Year Spectroscopic Sample.

    Science.gov (United States)

    Brout, Dillon

    2018-01-01

    We present cosmological parameter constraints from 251 spectroscopically confirmed Type Ia Supernovae (0.02 Supernova Program (DESSN). The photometric calibration, scene modeling photometric pipeline, additional low-z supernovae samples (zcosmological results and systematics analysis are discussed.

  2. Computing group cardinality constraint solutions for logistic regression problems.

    Science.gov (United States)

    Zhang, Yong; Kwon, Dongjin; Pohl, Kilian M

    2017-01-01

    We derive an algorithm to directly solve logistic regression based on cardinality constraint, group sparsity and use it to classify intra-subject MRI sequences (e.g. cine MRIs) of healthy from diseased subjects. Group cardinality constraint models are often applied to medical images in order to avoid overfitting of the classifier to the training data. Solutions within these models are generally determined by relaxing the cardinality constraint to a weighted feature selection scheme. However, these solutions relate to the original sparse problem only under specific assumptions, which generally do not hold for medical image applications. In addition, inferring clinical meaning from features weighted by a classifier is an ongoing topic of discussion. Avoiding weighing features, we propose to directly solve the group cardinality constraint logistic regression problem by generalizing the Penalty Decomposition method. To do so, we assume that an intra-subject series of images represents repeated samples of the same disease patterns. We model this assumption by combining series of measurements created by a feature across time into a single group. Our algorithm then derives a solution within that model by decoupling the minimization of the logistic regression function from enforcing the group sparsity constraint. The minimum to the smooth and convex logistic regression problem is determined via gradient descent while we derive a closed form solution for finding a sparse approximation of that minimum. We apply our method to cine MRI of 38 healthy controls and 44 adult patients that received reconstructive surgery of Tetralogy of Fallot (TOF) during infancy. Our method correctly identifies regions impacted by TOF and generally obtains statistically significant higher classification accuracy than alternative solutions to this model, i.e., ones relaxing group cardinality constraints. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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

  4. Constraint percolation on hyperbolic lattices

    Science.gov (United States)

    Lopez, Jorge H.; Schwarz, J. M.

    2017-11-01

    Hyperbolic lattices interpolate between finite-dimensional lattices and Bethe lattices, and they are interesting in their own right, with ordinary percolation exhibiting not one but two phase transitions. We study four constraint percolation models—k -core percolation (for k =1 ,2 ,3 ) and force-balance percolation—on several tessellations of the hyperbolic plane. By comparing these four different models, our numerical data suggest that all of the k -core models, even for k =3 , exhibit behavior similar to ordinary percolation, while the force-balance percolation transition is discontinuous. We also provide proof, for some hyperbolic lattices, of the existence of a critical probability that is less than unity for the force-balance model, so that we can place our interpretation of the numerical data for this model on a more rigorous footing. Finally, we discuss improved numerical methods for determining the two critical probabilities on the hyperbolic lattice for the k -core percolation models.

  5. Metric approach to quantum constraints

    International Nuclear Information System (INIS)

    Brody, Dorje C; Hughston, Lane P; Gustavsson, Anna C T

    2009-01-01

    A framework for deriving equations of motion for constrained quantum systems is introduced and a procedure for its implementation is outlined. In special cases, the proposed new method, which takes advantage of the fact that the space of pure states in quantum mechanics has both a symplectic structure and a metric structure, reduces to a quantum analogue of the Dirac theory of constraints in classical mechanics. Explicit examples involving spin-1/2 particles are worked out in detail: in the first example, our approach coincides with a quantum version of the Dirac formalism, while the second example illustrates how a situation that cannot be treated by Dirac's approach can nevertheless be dealt with in the present scheme.

  6. Space station neutral external environment

    Science.gov (United States)

    Ehlers, H.; Leger, L.

    1988-01-01

    Molecular contamination levels arising from the external induced neutral environment of the Space Station (Phase 1 configuration) were calculated using the MOLFLUX model. Predicted molecular column densities and deposition rates generally meet the Space Station contamination requirements. In the doubtful cases of deposition due to materials outgassing, proper material selection, generally excluding organic products exposed to the external environment, must be considered to meet contamination requirements. It is important that the Space Station configuration, once defined, is not significantly modified to avoid introducing new unacceptable contamination sources.

  7. Optical flow computation using extended constraints.

    Science.gov (United States)

    Del Bimbo, A; Nesi, P; Sanz, J C

    1996-01-01

    Several approaches for optical flow estimation use partial differential equations to model changes in image brightness throughout time. A commonly used equation is the so-called optical flow constraint (OFC), which assumes that the image brightness is stationary with respect to time. More recently, a different constraint referred to as the extended optical flow constraint (EOFC) has been introduced, which also contains the divergence of the flow field of image brightness. There is no agreement in the literature about which of these constraints provides the best estimation of the velocity field. Two new solutions for optical flow computation are proposed, which are based on an approximation of the constraint equations. The two techniques have been used with both EOFC and OFC constraint equations. Results achieved by using these solutions have been compared with several well-known computational methods for optical flow estimation in different motion conditions. Estimation errors have also been measured and compared for different types of motion.

  8. Use of dose constraints in public exposure

    International Nuclear Information System (INIS)

    Tageldein, Amged

    2015-02-01

    An overview of the dose constraints in public exposures has been carried out in this project. The establishment, development and the application of the concept of dose constraints are reviewed with regards to public exposure. The role of dose constraints in the process of optimization of radiation protection was described and has been showed that the concept of the dose constraints along with many other concept of radiation protection is widely applied in the optimization of exposure to radiation. From the beginning of the establishment of dose constraints as a concept in radiation protection, the International Commission of Radiological Protection (ICRP) has published a number of documents that provides detailed application related to radiation protection and safety of public exposure from ionizing radiation. This work provides an overview of such publications and related documents with special emphasis on optimization of public exposure using dose constraints. (au)

  9. Causality Constraints in Conformal Field Theory

    CERN Multimedia

    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...

  10. Constraint Embedding for Multibody System Dynamics

    Science.gov (United States)

    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.

  11. Automatic analysis of image quality control for Image Guided Radiation Therapy (IGRT) devices in external radiotherapy

    International Nuclear Information System (INIS)

    Torfeh, Tarraf

    2009-01-01

    On-board imagers mounted on a radiotherapy treatment machine are very effective devices that improve the geometric accuracy of radiation delivery. However, a precise and regular quality control program is required in order to achieve this objective. Our purpose consisted of developing software tools dedicated to an automatic image quality control of IGRT devices used in external radiotherapy: 2D-MV mode for measuring patient position during the treatment using high energy images, 2D-kV mode (low energy images) and 3D Cone Beam Computed Tomography (CBCT) MV or kV mode, used for patient positioning before treatment. Automated analysis of the Winston and Lutz test was also proposed. This test is used for the evaluation of the mechanical aspects of treatment machines on which additional constraints are carried out due to the on-board imagers additional weights. Finally, a technique of generating digital phantoms in order to assess the performance of the proposed software tools is described. Software tools dedicated to an automatic quality control of IGRT devices allow reducing by a factor of 100 the time spent by the medical physics team to analyze the results of controls while improving their accuracy by using objective and reproducible analysis and offering traceability through generating automatic monitoring reports and statistical studies. (author) [fr

  12. Some cosmological constraints on gauge theories

    International Nuclear Information System (INIS)

    Schramm, D.N.

    1983-01-01

    In these lectures, a review is made of various constraints cosmology may place on gauge theories. Particular emphasis is placed on those constraints obtainable from Big Bang Nucleosynthesis, with only brief mention made of Big Bang Baryosynthesis. There is also a considerable discussion of astrophysical constraints on masses and lifetimes of neutrinos with specific mention of the 'missing mass (light)' problem of galactic dynamics. (orig./HSI)

  13. Constraints on a massive Dirac neutrino model

    International Nuclear Information System (INIS)

    Wynter, T.; Randall, L.

    1994-01-01

    We examine constraints on a simple neutrino model in which there are three massless and three massive Dirac neutrinos and in which the left-handed neutrinos are linear combinations of doublet and singlet neutrinos. We examine constraints from direct decays into heavy neutrinos, indirect effects on electroweak parameters, and flavor-changing processes. We combine these constraints to examine the allowed mass range for the heavy neutrinos of each of the three generations

  14. Review of Minimal Flavor Constraints for Technicolor

    DEFF Research Database (Denmark)

    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 mas......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...

  15. PHOSPHORUS SORPTION ISOTHERMS AND EXTERNAL ...

    African Journals Online (AJOL)

    ACSS

    Zhang et al., 2005). For instance, in strongly acidic soils with pH<5.5 and high P sorbing soils, application of rock phosphate is more effective and cheaper than using TSP (Bationo et al., 2011). Moreover, it enables determination of the external P.

  16. Organizing for External Knowledge Sourcing

    DEFF Research Database (Denmark)

    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 o...

  17. Femoral Reconstruction Using External Fixation

    Directory of Open Access Journals (Sweden)

    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.

  18. Lupus vulgaris of external nose

    OpenAIRE

    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.

  19. Automated external defibrillators: design considerations.

    Science.gov (United States)

    Kroll, M W; Brewer, J E

    1997-05-01

    Biphasic defibrillation waveforms are now the standard of care in clinical use for defibrillation with implantable cardioverter-defibrillators (ICDs), due to the superior performance demonstrated over that of comparable monophasic waveforms. To better understand these significantly different outcomes, ICD research has developed cardiac cell response models to defibrillation. Waveform design criteria have been derived from these first principles and have been applied to monophasic and biphasic waveforms to optimize their parameters. These principles-based design criteria have produced significant improvements over the current art of waveforms. Monophasic defibrillation waveforms remain the standard of care in clinical use for transthoracic defibrillation. Waveform design has not yet been influenced by the important gains made in ICD research. The limitations of present transthoracic waveforms may be due in part to a lack of application of these design principles to determine optimal waveform characteristics. To overcome these limitations, design principles based on cell response have recently been developed for external defibrillation waveforms. The transthoracic model incorporates elements into a cell response model that extends it to external defibrillation. External waveform design principles demonstrate reductions in capacitance, voltage, duration, and delivered energy. Therefore, design principles based on cardiac electrophysiology may provide a means to significantly reduce the energy required for safe and efficacious external defibrillation. Footnotes, formulae, and figures augment this presentation in order to clarify the defibrillation waveform theory.

  20. EAMJ External Dec 09.indd

    African Journals Online (AJOL)

    2009-12-12

    Dec 12, 2009 ... the dental chair light and a dental probe. The tooth revealed the presence of at least two canal orifices on the floor of the pulp chamber. (iv) Three-rooted when three external roots were observed. Figure 1 (a-d) shows the four root types. Figure 1 (a-d). Premolars depicting one root (a), two distinct roots (b),.

  1. Dynamical Constraints on Non-Transiting Planets at Trappist-1

    Science.gov (United States)

    Jontof-Hutter, Daniel; Truong, Vinh; Ford, Eric; Robertson, Paul; Terrien, Ryan

    2018-04-01

    The outermost of the seven known planets of Trappist-1 orbits six times closer to its host star than Mercury orbits the sun. The architecture of this system beyond 0.07 AU remains unknown. While the presence of additional planets will ultimately be determined by observations, in the meantime, some constraints can be derived from dynamical models.We will firstly look at the expected signature of additional planets at Trappist-1 on the transit times of the known planets to determine at what distances putatuve planets can be ruled out.Secondly, the remarkably compact configuration of Trappist-1 ensures that the known planets are secularly coupled, keeping their mutual inclinations very small and making their cotransiting geometry likely if Trappist-1h transits. We determine the range of masses and orbital inclinations of a putatuve outer planet that would make the observed configuration unlikely, and compare these to these constraints to those expected from radial velocity observations.

  2. Constraint-based modeling of carbon fixation and the energetics of electron transfer in Geobacter metallireducens.

    Directory of Open Access Journals (Sweden)

    Adam M Feist

    2014-04-01

    Full Text Available Geobacter species are of great interest for environmental and biotechnology applications as they can carry out direct electron transfer to insoluble metals or other microorganisms and have the ability to assimilate inorganic carbon. Here, we report on the capability and key enabling metabolic machinery of Geobacter metallireducens GS-15 to carry out CO2 fixation and direct electron transfer to iron. An updated metabolic reconstruction was generated, growth screens on targeted conditions of interest were performed, and constraint-based analysis was utilized to characterize and evaluate critical pathways and reactions in G. metallireducens. The novel capability of G. metallireducens to grow autotrophically with formate and Fe(III was predicted and subsequently validated in vivo. Additionally, the energetic cost of transferring electrons to an external electron acceptor was determined through analysis of growth experiments carried out using three different electron acceptors (Fe(III, nitrate, and fumarate by systematically isolating and examining different parts of the electron transport chain. The updated reconstruction will serve as a knowledgebase for understanding and engineering Geobacter and similar species.

  3. Additional reactor protection system of RBMK-1500

    International Nuclear Information System (INIS)

    1999-01-01

    Analysis of anticipated transients without scram of RBMK-1500 reactor showed that additional reactor protection system is required. Data of accident analysis in the case of loose of external electric power and loose of vacuum in condensers of turbines are provided

  4. [Environmental efficiency evaluation under carbon emission constraint in Western China].

    Science.gov (United States)

    Rong, Jian-bo; Yan, Li-jiao; Huang, Shao-rong; Zhang, Ge

    2015-06-01

    This research used the SBM model based on undesirable outputs to measure the static environmental efficiency of Western China under carbon emission constraint from 2000 to 2012. The researchers also utilized the Malmquist index to further analyze the change tendency of environmental efficiency. Additionally, Tobit regression analysis was used to study the factors relevant to environmental efficiency. Practical solutions to improve environmental quality in Western China were put forward. The study showed that in Western China, environmental efficiency with carbon emission constraint was significantly lower than that without carbon emission constraint, and the difference could be described as an inverse U-shaped curve which increased at first and then decreased. Guang-xi and Inner Mongolia, the two provinces met the effective environmental efficiency levels all the time under carbon emission constraint. However, the five provinces of Guizhou, Gansu, Qinghai, Ningxia and Xinjiang did not. Furthermore, Ningxia had the lowest level of environmental efficiency, with a score between 0.281-0.386. Although the environmental efficiency of most provinces was currently at an ineffective level, the environmental efficiency quality was gradually improving at an average speed of 6.6%. Excessive CO2 emission and a large amount of energy consumption were the primary factors causing environmental inefficiency in Western China, and energy intensity had the most negative impact on the environmental efficiency. The increase of import and export trade reduced the environmental efficiency significantly in Western China, while the increase of foreign direct investment had a positive effect on its environmental efficiency.

  5. Technology for planning and scheduling under complex constraints

    Science.gov (United States)

    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.

  6. Optimal filters with heuristic 1-norm sparsity constraints

    Science.gov (United States)

    Yazdani, Mehrdad; Hecht-Nielsen, Robert

    2011-09-01

    We present a design method for sparse optimal Finite Impulse Response (FIR) filters that improve the visibility of a desired stochastic signal corrupted with white Gaussian noise. We emphasize that the filters we seek are of high-order but sparse, thus significantly reducing computational complexity. An optimal FIR filter for the estimation of a desired signal corrupted with white noise can be designed by maximizing the signal-to-noise ratio (SNR) of the filter output with the constraint that the magnitude (in 2-norm) of the FIR filter coefficients are set to unity.1, 2 This optimization problem is in essence maximizing the Rayleigh quotient and is thus equivalent to finding the eigenvector with the largest eigenvalue.3 While such filters are optimal, they are rarely sparse. To ensure sparsity, one must introduce a cardinality constraint in the optimization procedure. For high order filters such constraints are computationally burdensome due to the combinatorial search space. We relax the cardinality constraint by using the 1-norm approximation of the cardinality function. This is a relaxation heuristic similar to the recent sparse filter design work of Baran, Wei, and Oppenheim.4 The advantage of this relaxation heuristic is that the solutions tend to be sparse and the optimization procedure reduces to a convex program, thus ensuring global optimality. In addition to our proposed optimization procedure for deriving sparse FIR filters, we show examples where sparse high-order filters significantly perform better than low-order filters, whereas complexity is reduced by a factor of 10.

  7. A New Gaze Estimation Method Considering External Light

    Directory of Open Access Journals (Sweden)

    Jong Man Lee

    2015-03-01

    Full Text Available Gaze tracking systems usually utilize near-infrared (NIR lights and NIR cameras, and the performance of such systems is mainly affected by external light sources that include NIR components. This is ascribed to the production of additional (imposter corneal specular reflection (SR caused by the external light, which makes it difficult to discriminate between the correct SR as caused by the NIR illuminator of the gaze tracking system and the imposter SR. To overcome this problem, a new method is proposed for determining the correct SR in the presence of external light based on the relationship between the corneal SR and the pupil movable area with the relative position of the pupil and the corneal SR. The experimental results showed that the proposed method makes the gaze tracking system robust to the existence of external light.

  8. Negatively correlated local and global stock externalities: tax or subsidy?

    International Nuclear Information System (INIS)

    Zili Yang

    2006-01-01

    Fossil fuel combustion generates both CO 2 and SO 2 . CO 2 is the most important greenhouse gas; SO 2 can cause serious local pollution. But it can alleviate the potential global warming because of negative radiative forcing. Such a phenomenon can be characterized as negatively correlated local and global stock externalities. In this paper, we set up an optimal control problem of negatively correlated local and global stock externality provision. The efficiency conditions for this problem are derived. These conditions modify the Samuelson rules for optimal provision of externalities. In addition, we examine several policy related scenarios of negatively correlated local and global stock externality provisions. Finally, we discuss policy implications and limitation of the theoretical results derived in this paper. We also indicate applications of the theoretical results here to empirical research, particularly to economic analysis of multiple-gas issues in climate change. (Author)

  9. Neuroadaptive Fault-Tolerant Control of Nonlinear Systems Under Output Constraints and Actuation Faults.

    Science.gov (United States)

    Zhao, Kai; Song, Yongduan; Shen, Zhixi

    2018-02-01

    In this paper, a neuroadaptive fault-tolerant tracking control method is proposed for a class of time-delay pure-feedback systems in the presence of external disturbances and actuation faults. The proposed controller can achieve prescribed transient and steady-state performance, despite uncertain time delays and output constraints as well as actuation faults. By combining a tangent barrier Lyapunov-Krasovskii function with the dynamic surface control technique, the neural network unit in the developed control scheme is able to take its action from the very beginning and play its learning/approximating role safely during the entire system operational envelope, leading to enhanced control performance without the danger of violating compact set precondition. Furthermore, prescribed transient performance and output constraints are strictly ensured in the presence of nonaffine uncertainties, external disturbances, and undetectable actuation faults. The control strategy is also validated by numerical simulation.

  10. Phonological Constraint Induction in a Connectionist Network: Learning OCP-Place Constraints from Data

    Science.gov (United States)

    Alderete, John; Tupper, Paul; Frisch, Stefan A.

    2013-01-01

    A significant problem in computational language learning is that of inferring the content of well-formedness constraints from input data. In this article, we approach the constraint induction problem as the gradual adjustment of subsymbolic constraints in a connectionist network. In particular, we develop a multi-layer feed-forward network that…

  11. Optimal Portfolio Choice with Wash Sale Constraints

    DEFF Research Database (Denmark)

    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...

  12. Constraints In Implementating The Agricultural Sector Employment ...

    African Journals Online (AJOL)

    ... the Agency-related constraints to effective programme implementation. High cost of transportation, problems of pests and diseases and difficulty in acquiring enough land for farming were some of the socio-cultural/environmental constraints to effective programme implementation. Global Approaches to Extension Practice ...

  13. Climate Change Adaptation Constraints among Smallholder ...

    African Journals Online (AJOL)

    The mean ranks of the constraints significantly differ from one another with the three topmost constraints being unreliable water source, lack of information on climate change and limited income. But for crop diversification, poor extension services and lack of credit are factors that cut across all the identified adaptation ...

  14. Integrity Constraints in Trust Management (Extended Abstract)

    NARCIS (Netherlands)

    Etalle, Sandro; Winsborough, William H.; Ahn, G-J.

    We introduce the use, monitoring, and enforcement of integrity constraints in trust managementstyle authorization systems. We consider what portions of the policy state must be monitored to detect violations of integrity constraints. Then we address the fact that not all participants in a trust

  15. Quantum Einstein's equations and constraints algebra

    Indian Academy of Sciences (India)

    In this paper we shall address this problem: Is quantum gravity constraints algebra closed and what are the quantum Einstein's equations. We shall investigate this problem in the deBroglie–Bohm quantum theory framework. It is shown that the constraint algebra is weakly closed and the quantum Einstein's equations are ...

  16. The Ambiguous Role of Constraints in Creativity

    DEFF Research Database (Denmark)

    Biskjær, Michael Mose; Onarheim, Balder; Wiltschnig, Stefan

    2011-01-01

    . In this paper, we explore these particular issues in two creative domains: art and engineering design. These domains vary so greatly in terms of number and types of constraints in play that we argue for considering them as opposite extremes of a continuum of levels of creative freedom. By comparing two case......-disciplinary research into the ambiguous role of constraints in creativity....

  17. Supernova constraints on neutrino mass and mixing

    Indian Academy of Sciences (India)

    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 ...

  18. Filtering Algorithms for Global Chance Constraints

    NARCIS (Netherlands)

    Hnich, B.; Rossi, R.; Tarim, S.A.; Prestwich, S.

    2012-01-01

    Stochastic Constraint Satisfaction Problems (SCSPs) are a powerful modeling framework for problems under uncertainty. To solve them is a PSPACE task. The only complete solution approach to date — scenario-based stochastic constraint programming — compiles SCSPs down into classical CSPs. This allows

  19. Principles and Practice of Constraint Programming

    NARCIS (Netherlands)

    Zampelli, Stéphane; Vergados, Yannis; Van Schaeren, Rowan; Dullaert, Wout; Raa, Birger

    2013-01-01

    This paper considers the combination of berth and crane allocation problems in container terminals. We propose a novel approach based on constraint programming which is able to model many realistic operational constraints. The costs for berth allocation, crane allocation, time windows, breaks and

  20. A Temporal Concurrent Constraint Programming Calculus

    DEFF Research Database (Denmark)

    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...

  1. A model for strategy in constraint solving

    NARCIS (Netherlands)

    J.J. van Wijk (Jack)

    1997-01-01

    textabstractThe use of constraints for the definition of graphical user interfaces has been recognized as a great concept. However, often many valuations of the variables will satisfy the constraints, and which particular valuation matches best with the expectation of the user cannot be decided

  2. Missed opportunities and caretaker constraints to childhood ...

    African Journals Online (AJOL)

    Background: Despite concerted support to vaccination programmes, coverage remains low. While health service reasons for this are known, there is little information on caretaker constraints to vaccination in Africa. Objective: To establish the prevalence of missed vaccination opportunities and caretaker constraints to ...

  3. Modifier constraints in alkali ultraphosphate glasses

    DEFF Research Database (Denmark)

    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 limitat...

  4. VOCABULARY CONSTRAINT ON READING MATERIALS

    Directory of Open Access Journals (Sweden)

    Cucu Sutarsyah

    2016-02-01

    Full Text Available The aim of the study is to identify and describe the vocabulary in reading materials and to seek if the texts are useful for reading skill development. A descriptive qualitative design was applied to obtain the data. Some available computer programs were used to find the description of vocabulary in the texts. It was found that the texts are dominated by low frequency words which compose 16.97% of the words in the texts. In terms of high frequency words occurring in the texts, function words dominate the texts. In the case of word levels, it was found that the texts being used have very limited number of words from GSL (West, 1953. The proportion of the first 1,000 words of GSL only comprises 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 constitute 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 impede the development of students' reading skills and vocabulary enrichment.

  5. Cosmological constraints on quintessential halos

    CERN Document Server

    Arbey, A; Salati, Pierre; Arbey, Alexandre; Lesgourgues, Julien; Salati, Pierre

    2002-01-01

    A complex scalar field has recently been suggested to bind galaxies and flatten the rotation curves of spirals. Its cosmological behavior is thoroughly investigated here. Such a field is shown to be a potential candidate for the cosmological dark matter that fills up a fraction Omega_cdm = 0.3 of the Universe. However, problems arise when the limits from galactic dynamics and some cosmological constraints are taken simultaneously into account. A free complex field, associated to a very small mass m = 10^{-23} eV, has a correct cosmological behavior in the early Universe, but behaves today mostly as a real axion, with a problematic value of its conserved quantum number. On the other hand, an interacting field with quartic coupling lambda = 0.1 has a more realistic mass m = 1 eV and carries a quantum number close to the photon number density. Unlike a free field, it would be spinning today in the complex plane - like the so-called ``spintessence''. Unfortunately, the cosmological evolution of such field in the ...

  6. Internal and external regulation of plant organ stoichiometry.

    Science.gov (United States)

    Minden, V; Kleyer, M

    2014-09-01

    Internal differences between plant organs are caused by the functional differentiation of plant tissue, whereas external supply rates of elements constrain nutrient uptake. Previous studies have concentrated on foliar or whole-plant stoichiometric response to the environment, whereas investigation of organ-specific comparisons is still pending. We explore C:N:P ratios of stems, leaves, diaspores and belowground organs in marsh plants, and evaluate the influence of environmental constraints using standardised major axis regression (SMA). For a pooled dataset, SMA resulted in distinct patterns of isometric and anisometric slopes between plant organs. Bivariate line-fitting for a split dataset of four ecological groups revealed that species of the frequently inundated marsh had higher N:C ratios than those of the infrequently inundated marsh. The influence of nutrient availability was detectable in decreased P:C and increased N:P ratios in P-poor sites. Across ecological groups, leaves and diaspores showed higher elemental homeostasis than stems and belowground organs. Any change in N:C ratios of belowground organs and diaspores in response to the environment was accompanied by an even stronger internal change in stem N:C ratios, indicating a pivotal role of stems of herbaceous plants in ecosystem processes. We found distinct patterns of C:N:P ratios in plant organs related to their internal function and external environmental constraints. Leaves and diaspores showed a higher degree of homeostasis than stems and belowground organs. We detected a clear external signal in element:element ratios of plant organs, with low soil P translating into lower tissue P:C ratio and stronger N retention in leaves as a response to salt stress. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  7. Two Constraints on Tonal Derivation in Chinese

    Directory of Open Access Journals (Sweden)

    Hui-chuan Hsu

    2005-12-01

    Full Text Available This paper aims to further examine two working constraints on tonal derivation proposed in some recent generative studies on Changting, namely One Step Principle (OSP and Moving Windows Constraint (MWC. Our extension of the scope of discussion to other Chinese dialects leads to the necessity of proposing the more general Domain Constraint (DC which subsumes the MWC. The comparison and contrast between OSP and DC exhibits a see-saw battle at present. Both successfully account for Dongshi Hakka, Tianjin, and Yaoping. OSP wins in Changting (Chen 2003, Chen et al. 2004 and fast speeches in Xuzhou and Standard Mandarin. Different form the above-mentioned cases, Tianjin fast speech demonstrates a dual nature in regard to both constraints. Furthermore, DC receives non-Sinitic support from Hakha Lai; segmental derivation of fanqie languages reveals an OSP counterpart. How these two constraints behave in African tone languages awaits further study.

  8. Constraint Specialisation in Horn Clause Verification

    DEFF Research Database (Denmark)

    Kafle, Bishoksan; Gallagher, John Patrick

    2015-01-01

    -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......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...... results on verification problems show that this is an effective transformation, both in our own verification tools (convex polyhedra analyser) and as a pre-processor to other Horn clause verification tools....

  9. Assimilation of PFISR Data Using Support Vector Regression and Ground Based Camera Constraints

    Science.gov (United States)

    Clayton, R.; Lynch, K. A.; Nicolls, M. J.; Hampton, D. L.; Michell, R.; Samara, M.; Guinther, J.

    2013-12-01

    In order to best interpret the information gained from multipoint in situ measurements, a Support Vector Regression algorithm is being developed to interpret the data collected from the instruments in the context of ground observations (such as those from camera or radar array). The idea behind SVR is to construct the simplest function that models the data with the least squared error, subject to constraints given by the user. Constraints can be brought into the algorithm from other data sources or from models. As is often the case with data, a perfect solution to such a problem may be impossible, thus 'slack' may be introduced to control how closely the model adheres to the data. The algorithm employs kernels, and chooses radial basis functions as an appropriate kernel. The current SVR code can take input data as one to three dimensional scalars or vectors, and may also include time. External data can be incorporated and assimilated into a model of the environment. Regions of minimal and maximal values are allowed to relax to the sample average (or a user-supplied model) on size and time scales determined by user input, known as feature sizes. These feature sizes can vary for each degree of freedom if the user desires. The user may also select weights for each data point, if it is desirable to weight parts of the data differently. In order to test the algorithm, Poker Flat Incoherent Scatter Radar (PFISR) and MICA sounding rocket data are being used as sample data. The PFISR data consists of many beams, each with multiple ranges. In addition to analyzing the radar data as it stands, the algorithm is being used to simulate data from a localized ionospheric swarm of Cubesats using existing PFISR data. The sample points of the radar at one altitude slice can serve as surrogates for satellites in a cubeswarm. The number of beams of the PFISR radar can then be used to see what the algorithm would output for a swarm of similar size. By using PFISR data in the 15-beam to

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

    International Nuclear Information System (INIS)

    Krewitt, W.

    2002-01-01

    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)

  11. Fuzzy Control of DC-DC Converters with Input Constraint

    Directory of Open Access Journals (Sweden)

    D. Saifia

    2012-01-01

    Full Text Available This paper proposes a method for designing fuzzy control of DC-DC converters under actuator saturation. Because linear control design methods do not take into account the nonlinearity of the system, a T-S fuzzy model and a controller design approach is used. The designed control not only handles the external disturbance but also the saturation of duty cycle. The input constraint is first transformed into a symmetric saturation which is represented by a polytopic model. Stabilization conditions for the state feedback system of DC-DC converters under actuator saturation are established using the Lyapunov approach. The proposed method has been compared and verified with a simulation example.

  12. MGR External Events Hazards Analysis

    International Nuclear Information System (INIS)

    Booth, L.

    1999-01-01

    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

  13. Firm Search for External Knowledge

    DEFF Research Database (Denmark)

    Sofka, Wolfgang; Grimpe, Christoph

    2012-01-01

    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......The innovation performance of modern firms is increasingly determined by their ability to search and absorb external knowledge. However, after a certain threshold firms "oversearch" their environment and innovation performance declines. In this paper, we argue that prior literature has largely...... 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...

  14. MGR External Events Hazards Analysis

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Conceptual challenges for internalising externalities

    DEFF Research Database (Denmark)

    Miguel, Brandão; Weidema, Bo Pedersen

    2013-01-01

    We analyse a number of different externalities to identify conceptual challenges for the practical implementation of their internalisation. Three issues were identified: i) The balance between compensation and technology change and the respective effects on the nominal and real GDP; ii) The relev......We analyse a number of different externalities to identify conceptual challenges for the practical implementation of their internalisation. Three issues were identified: i) The balance between compensation and technology change and the respective effects on the nominal and real GDP; ii......) The relevance and efficiency of different instruments for internalisation and compensation; and iii) Implementing internalisation over large geographical and temporal distances. We find taxation to be a more relevant and efficient tool for internalisation than insurance and litigation. With increasing...

  16. BOP Crises and External Shocks

    OpenAIRE

    Kitano, Shigeto

    2003-01-01

    This is a theoretical study of BOP crises in emerging markets in East Asia and LatinAmerica in the l990s. These BOP crises tend to be preceded by the current account deterioration, the real exchange rate appreciation, and inflationary pressures. The paper develops a model of BOP crises preceded by these macroeconomic phenomena. The model shows that an external shock (a decrease in the world nominal interest rate) leads to this type of BOP crises.

  17. Acute incarcerated external abdominal hernia

    OpenAIRE

    Yang, Xue-Fei; Liu, Jia-Lin

    2014-01-01

    External abdominal hernia occurs when abdominal organs or tissues leave their normal anatomic site and protrude outside the skin through the congenital or acquired weakness, defects or holes on the abdominal wall, including inguinal hernia, umbilical hernia, femoral hernia and so on. Acute incarcerated hernia is a common surgical emergency. With advances in minimally invasive devices and techniques, the diagnosis and treatment have witnessed major changes, such as the use of laparoscopic surg...

  18. Personnel external dose monitoring system

    International Nuclear Information System (INIS)

    Zhao Hengyuan

    1989-01-01

    The status and trend of personnel external dose monitoring system are introduced briefly. Their characteristics, functions and TLD bedges of some commercially available automatic TLD system, including UD-710A (Matsushita, Japan), Harshaw-2271, 2276 (Harshaw, USA), Harshaw-8000 (Harshaw/Filtrol), Studsvik-1313 (Sweden) and Pitman-800 (UK) were depicted in detail. Finally, personnel dose management and record keeping system were presented and two examples were given

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

    International Nuclear Information System (INIS)

    Friedrich, R.; Krewitt, W.; Mayerhofer, P.

    1995-01-01

    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

  20. Physical activity participation and constraints among athletic training students.

    Science.gov (United States)

    Stanek, Justin; Rogers, Katherine; Anderson, Jordan

    2015-02-01

    Researchers have examined the physical activity (PA) habits of certified athletic trainers; however, none have looked specifically at athletic training students. To assess PA participation and constraints to participation among athletic training students. Cross-sectional study. Entry-level athletic training education programs (undergraduate and graduate) across the United States. Participants were 1125 entry-level athletic training students. Self-reported PA participation, including a calculated PA index based on a typical week. Leisure constraints and demographic data were also collected. Only 22.8% (252/1105) of athletic training students were meeting the American College of Sports Medicine recommendations for PA through moderate-intensity cardiorespiratory exercise. Although 52.3% (580/1105) were meeting the recommendations through vigorous-intensity cardiorespiratory exercise, 60.5% (681/1125) were meeting the recommendations based on the combined total of moderate or vigorous cardiorespiratory exercise. In addition, 57.2% (643/1125) of respondents met the recommendations for resistance exercise. Exercise habits of athletic training students appear to be better than the national average and similar to those of practicing athletic trainers. Students reported structural constraints such as lack of time due to work or studies as the most significant barrier to exercise participation. Athletic training students experienced similar constraints to PA participation as practicing athletic trainers, and these constraints appeared to influence their exercise participation during their entry-level education. Athletic training students may benefit from a greater emphasis on work-life balance during their entry-level education to promote better health and fitness habits.

  1. Robust Unit Commitment Including Frequency Stability Constraints

    Directory of Open Access Journals (Sweden)

    Felipe Pérez-Illanes

    2016-11-01

    Full Text Available An increased use of variable generation technologies such as wind power and photovoltaic generation can have important effects on system frequency performance during normal operation as well as contingencies. The main reasons are the operational principles and inherent characteristics of these power plants like operation at maximum power point and no inertial response during power system imbalances. This has led to new challenges for Transmission System Operators in terms of ensuring system security during contingencies. In this context, this paper proposes a Robust Unit Commitment including a set of additional frequency stability constraints. To do this, a simplified dynamic model of the initial system frequency response is used in combination with historical frequency nadir data during contingencies. The proposed approach is especially suitable for power systems with cost-based economic dispatch like those in most Latin American countries. The study is done considering the Northern Interconnected System of Chile, a 50-Hz medium size isolated power system. The results obtained were validated by means of dynamic simulations of different system contingencies.

  2. Constraints on dark radiation from cosmological probes

    CERN Document Server

    Rossi, Graziano; Palanque-Delabrouille, Nathalie; Lesgourgues, Julien

    2015-01-01

    We present joint constraints on the number of effective neutrino species N_eff and the sum of neutrino masses M_nu, based on a technique which exploits the full information contained in the one-dimensional Lyman-Alpha forest flux power spectrum, complemented by additional cosmological probes. In particular, we obtain N_eff=2.91(+0.21)(-0.22) (95% CL) and M_nu<0.15 eV (95% CL) when we combine BOSS Lyman-Alpha forest data with CMB (Planck+ACT+SPT+WMAP polarization) measurements, and N_eff=2.88(+0.20)(-0.20) (95% CL) and M_nu<0.14 eV (95% CL) when we further add baryon acoustic oscillations. Our results provide evidence for the Cosmic Neutrino Background from N_eff~3 (N_eff=0 is rejected at more than 14 sigma), and rule out the possibility of a sterile neutrino thermalized with active neutrinos (i.e., N_eff=4) - or more generally any decoupled relativistic relic with Delta N_eff ~ 1 - at a significance of over 5 sigma, the strongest bound to date, implying that there is no need for exotic neutrino physics ...

  3. Cosmological constraints on interacting light particles

    Science.gov (United States)

    Brust, Christopher; Cui, Yanou; Sigurdson, Kris

    2017-08-01

    Cosmological observations are becoming increasingly sensitive to the effects of light particles in the form of dark radiation (DR) at the time of recombination. The conventional observable of effective neutrino number, Neff, is insufficient for probing generic, interacting models of DR. In this work, we perform likelihood analyses which allow both free-streaming effective neutrinos (parametrized by Neff) and interacting effective neutrinos (parametrized by Nfld). We motivate an alternative parametrization of DR in terms of Ntot (total effective number of neutrinos) and ffs (the fraction of effective neutrinos which are free-streaming), which is less degenerate than using Neff and Nfld. Using the Planck 2015 likelihoods in conjunction with measurements of baryon acoustic oscillations (BAO), we find constraints on the total amount of beyond the Standard Model effective neutrinos (both free-streaming and interacting) of Δ Ntot < 0.39 at 2σ. In addition, we consider the possibility that this scenario alleviates the tensions between early-time and late-time cosmological observations, in particular the measurements of σ8 (the amplitude of matter power fluctuations at 8h-1 Mpc), finding a mild preference for interactions among light species. We further forecast the sensitivities of a variety of future experiments, including Advanced ACTPol (a representative CMB Stage-III experiment), CMB Stage-IV, and the Euclid satellite. This study is relevant for probing non-standard neutrino physics as well as a wide variety of new particle physics models beyond the Standard Model that involve dark radiation.

  4. Natural Constraints to Species Diversification.

    Directory of Open Access Journals (Sweden)

    Eric Lewitus

    2016-08-01

    Full Text Available Identifying modes of species diversification is fundamental to our understanding of how biodiversity changes over evolutionary time. Diversification modes are captured in species phylogenies, but characterizing the landscape of diversification has been limited by the analytical tools available for directly comparing phylogenetic trees of groups of organisms. Here, we use a novel, non-parametric approach and 214 family-level phylogenies of vertebrates representing over 500 million years of evolution to identify major diversification modes, to characterize phylogenetic space, and to evaluate the bounds and central tendencies of species diversification. We identify five principal patterns of diversification to which all vertebrate families hold. These patterns, mapped onto multidimensional space, constitute a phylogenetic space with distinct properties. Firstly, phylogenetic space occupies only a portion of all possible tree space, showing family-level phylogenies to be constrained to a limited range of diversification patterns. Secondly, the geometry of phylogenetic space is delimited by quantifiable trade-offs in tree size and the heterogeneity and stem-to-tip distribution of branching events. These trade-offs are indicative of the instability of certain diversification patterns and effectively bound speciation rates (for successful clades within upper and lower limits. Finally, both the constrained range and geometry of phylogenetic space are established by the differential effects of macroevolutionary processes on patterns of diversification. Given these properties, we show that the average path through phylogenetic space over evolutionary time traverses several diversification stages, each of which is defined by a different principal pattern of diversification and directed by a different macroevolutionary process. The identification of universal patterns and natural constraints to diversification provides a foundation for understanding the

  5. Natural Constraints to Species Diversification.

    Science.gov (United States)

    Lewitus, Eric; Morlon, Hélène

    2016-08-01

    Identifying modes of species diversification is fundamental to our understanding of how biodiversity changes over evolutionary time. Diversification modes are captured in species phylogenies, but characterizing the landscape of diversification has been limited by the analytical tools available for directly comparing phylogenetic trees of groups of organisms. Here, we use a novel, non-parametric approach and 214 family-level phylogenies of vertebrates representing over 500 million years of evolution to identify major diversification modes, to characterize phylogenetic space, and to evaluate the bounds and central tendencies of species diversification. We identify five principal patterns of diversification to which all vertebrate families hold. These patterns, mapped onto multidimensional space, constitute a phylogenetic space with distinct properties. Firstly, phylogenetic space occupies only a portion of all possible tree space, showing family-level phylogenies to be constrained to a limited range of diversification patterns. Secondly, the geometry of phylogenetic space is delimited by quantifiable trade-offs in tree size and the heterogeneity and stem-to-tip distribution of branching events. These trade-offs are indicative of the instability of certain diversification patterns and effectively bound speciation rates (for successful clades) within upper and lower limits. Finally, both the constrained range and geometry of phylogenetic space are established by the differential effects of macroevolutionary processes on patterns of diversification. Given these properties, we show that the average path through phylogenetic space over evolutionary time traverses several diversification stages, each of which is defined by a different principal pattern of diversification and directed by a different macroevolutionary process. The identification of universal patterns and natural constraints to diversification provides a foundation for understanding the deep-time evolution of

  6. Structure formation cosmic rays: Identifying observational constraints

    Directory of Open Access Journals (Sweden)

    Prodanović T.

    2005-01-01

    Full Text Available Shocks that arise from baryonic in-fall and merger events during the structure formation are believed to be a source of cosmic rays. These "structure formation cosmic rays" (SFCRs would essentially be primordial in composition, namely, mostly made of protons and alpha particles. However, very little is known about this population of cosmic rays. One way to test the level of its presence is to look at the products of hadronic reactions between SFCRs and the ISM. A perfect probe of these reactions would be Li. The rare isotope Li is produced only by cosmic rays, dominantly in αα → 6Li fusion reactions with the ISM helium. Consequently, this nuclide provides a unique diagnostic of the history of cosmic rays. Exactly because of this unique property is Li affected most by the presence of an additional cosmic ray population. In turn, this could have profound consequences for the Big-Bang nucleosynthesis: cosmic rays created during cosmic structure formation would lead to pre-Galactic Li production, which would act as a "contaminant" to the primordial 7Li content of metalpoor halo stars. Given the already existing problem of establishing the concordance between Li observed in halo stars and primordial 7Li as predicted by the WMAP, it is crucial to set limits to the level of this "contamination". However, the history of SFCRs is not very well known. Thus we propose a few model-independent ways of testing the SFCR species and their history, as well as the existing lithium problem: 1 we establish the connection between gamma-ray and Li production, which enables us to place constraints on the SFCR-made lithium by using the observed Extragalactic Gamma-Ray Background (EGRB; 2 we propose a new site for testing the primordial and SFCR-made lithium, namely, low-metalicity High-Velocity Clouds (HVCs, which retain the pre-Galactic composition without any significant depletion. Although using one method alone may not give us strong constraints, using them in

  7. Improving the Held and Karp Approach with Constraint Programming

    Science.gov (United States)

    Benchimol, Pascal; Régin, Jean-Charles; Rousseau, Louis-Martin; Rueher, Michel; van Hoeve, Willem-Jan

    Held and Karp have proposed, in the early 1970s, a relaxation for the Traveling Salesman Problem (TSP) as well as a branch-and-bound procedure that can solve small to modest-size instances to optimality [4, 5]. It has been shown that the Held-Karp relaxation produces very tight bounds in practice, and this relaxation is therefore applied in TSP solvers such as Concorde [1]. In this short paper we show that the Held-Karp approach can benefit from well-known techniques in Constraint Programming (CP) such as domain filtering and constraint propagation. Namely, we show that filtering algorithms developed for the weighted spanning tree constraint [3, 8] can be adapted to the context of the Held and Karp procedure. In addition to the adaptation of existing algorithms, we introduce a special-purpose filtering algorithm based on the underlying mechanisms used in Prim's algorithm [7]. Finally, we explored two different branching schemes to close the integrality gap. Our initial experimental results indicate that the addition of the CP techniques to the Held-Karp method can be very effective.

  8. IRIS Toxicological Review of Ammonia (Revised External ...

    Science.gov (United States)

    In August 2013, EPA submitted a revised draft IRIS assessment of ammonia to the agency's Science Advisory Board (SAB) and posted this draft on the IRIS website. EPA had previously released a draft of the assessment for public comment, held a public meeting about the draft, and then revised it based on the comments received. The SAB CAAC-Ammonia panel will review this draft assessment. Details about the meeting dates, times, and location are available via the Federal Register Notice posted on March 25, 2014. The SAB provided information on how the public can participate in the external peer review meetings, as well as instructions about how to provide comments to the SAB in the notice. Additional information on the SAB review of ammonia is on the SAB website. Report Information: The Toxicological Review of Ammonia was originally released for a 60-day public comment period on June 8, 2012. [Federal Register Notice Jun 8, 2012] EPA revised the toxicological review in response to the public comments received. EPA has released the revised external review draft ammonia assessment and the SAB CAAC is conducting a peer review of the scientific basis supporting the assessment that will appear in the Integrated Risk Information System (IRIS) database. Information regarding the peer review can be found at the SAB review of ammonia website. EPA is undertaking an Integrated Risk Information System (IRIS) health assessment for ammonia. IRIS is an EPA database cont

  9. A new external microbeam system in Fudan University

    International Nuclear Information System (INIS)

    Zheng, Y.; Shen, H.; Li, Y.Q.; Li, X.Y.; Yang, M.J.; Mi, Y.

    2013-01-01

    A cost-effective and removable external beam system is set up based on the Oxford Microbeam system in Fudan University. In our external beam system, 7.5-μm-thick Kapton film is used as exit window with a diameter of 3.5 mm. The spatial resolution is about 18 μm full width at half maximum (FWHM) on a copper grid. As an example, calcium distribution in otolith is present by the external micro-PIXE. In addition, little change can be done to the external system mentioned above for radiobiology experiments. The exit window can be changed from the focal plane to the observation window of vacuum chamber. By calculation, the beam spot size can reach less than 30 μm. Since the Oxford type octagonal target chamber is popular among the nuclear microprobe facilities, this method can be provided to easily replace the in-vacuum system with the external system, extending the in-vacuum analysis to external beam analysis

  10. A new external microbeam system in Fudan University

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Y.; Shen, H., E-mail: haoshen@fudan.edu.cn; Li, Y.Q.; Li, X.Y.; Yang, M.J.; Mi, Y.

    2013-07-01

    A cost-effective and removable external beam system is set up based on the Oxford Microbeam system in Fudan University. In our external beam system, 7.5-μm-thick Kapton film is used as exit window with a diameter of 3.5 mm. The spatial resolution is about 18 μm full width at half maximum (FWHM) on a copper grid. As an example, calcium distribution in otolith is present by the external micro-PIXE. In addition, little change can be done to the external system mentioned above for radiobiology experiments. The exit window can be changed from the focal plane to the observation window of vacuum chamber. By calculation, the beam spot size can reach less than 30 μm. Since the Oxford type octagonal target chamber is popular among the nuclear microprobe facilities, this method can be provided to easily replace the in-vacuum system with the external system, extending the in-vacuum analysis to external beam analysis.

  11. A new external microbeam system in Fudan University

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Y. [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Shen, H., E-mail: haoshen@fudan.edu.cn [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Li, Y.Q.; Li, X.Y.; Yang, M.J.; Mi, Y. [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China)

    2013-02-01

    A cost-effective and removable external beam system is set up based on the Oxford Microbeam system in Fudan University. In our external beam system, 7.5-μm-thick Kapton film is used as exit window with a diameter of 3.5 mm. The spatial resolution is about 18 μm full width at half maximum (FWHM) on a copper grid. As an example, calcium distribution in otolith is present by the external micro-PIXE. In addition, little change can be done to the external system mentioned above for radiobiology experiments. The exit window can be changed from the focal plane to the observation window of vacuum chamber. By calculation, the beam spot size can reach less than 30 μm. Since the Oxford type octagonal target chamber is popular among the nuclear microprobe facilities, this method can be provided to easily replace the in-vacuum system with the external system, extending the in-vacuum analysis to external beam analysis.

  12. Constraint satisfaction problems CSP formalisms and techniques

    CERN Document Server

    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

  13. Black hole thermodynamics from Euclidean horizon constraints.

    Science.gov (United States)

    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.

  14. Use of dose constraints for occupational exposure

    International Nuclear Information System (INIS)

    Kaijage, Tunu

    2015-02-01

    The use of dose constraints for occupational exposure was reviewed in this project. The role of dose constraints as used in optimization of protection of workers was described. Different issues to be considered in application of the concept and challenges associated with their implementation were also discussed. The situation where dose constraints could be misinterpreted to dose limits is also explained as the two are clearly differentiated by the International Commission of Radiological Protection (ICRP) Publication 103. Moreover, recommendations to all parties responsible for protection and safety of workers were discussed. (au)

  15. Expressing Model Constraints Visually with VMQL

    DEFF Research Database (Denmark)

    Störrle, Harald

    2011-01-01

    ) 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, VMQL......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...

  16. Constraint-induced sound therapy for sudden sensorineural hearing loss – behavioral and neurophysiological outcomes

    Science.gov (United States)

    Okamoto, Hidehiko; Fukushima, Munehisa; Teismann, Henning; Lagemann, Lothar; Kitahara, Tadashi; Inohara, Hidenori; Kakigi, Ryusuke; Pantev, Christo

    2014-01-01

    Sudden sensorineural hearing loss is characterized by acute, idiopathic hearing deterioration. We report here the development and evaluation of “constraint-induced sound therapy”, which is based on a well-established neuro-rehabilitation approach, and which is characterized by the plugging of the intact ear (“constraint”) and the simultaneous, extensive stimulation of the affected ear with music. The sudden sensorineural hearing loss patients who received the constraint-induced sound therapy in addition to the standard corticosteroid therapy showed significantly better recovery of hearing function compared to those who had only received corticosteroid treatments. Additionally, the brain activity obtained in a subgroup of patients suggested that the constraint-induced sound therapy could have prevented maladaptive auditory cortex reorganization. Constraint-induced sound therapy thus appears to be an effective, practical, and safe treatment option for sudden sensorineural hearing loss. PMID:24473277

  17. Cosmological Constraints from Galaxy Clustering and Weak Lensing

    Science.gov (United States)

    Troxel, Michael; DES Collaboration

    2018-01-01

    The Dark Energy Survey (DES) is a five-year, 5000 sq. deg. observing program using the Dark Energy Camera on the 4m Blanco telescope at CTIO. I will describe the cosmological analysis of large-scale structure in the Universe using 1321 sq. deg. of data taken in the first year of DES operations. The analysis combines unprecedented measurements of weak gravitational lensing and the clustering of galaxies over the redshift range 0.2 to 1.3 to derive the most precise such cosmological constraints to date. These DES results from the low-redshift Universe are consistent with those from the cosmic microwave background (CMB) and support the standard cosmological model, LCDM. In the coming years, DES will produce significantly tighter constraints on cosmology through similar and additional analyses using observations over more than three times the sky-area and more than twice the integrated exposure time per object as these results.

  18. Self-injury and externalizing pathology: a systematic literature review.

    Science.gov (United States)

    Meszaros, Gergely; Horvath, Lili Olga; Balazs, Judit

    2017-05-03

    During the last decade there is a growing scientific interest in nonsuicidal self-injury (NSSI). The aim of the current paper was to review systematically the literature with a special focus on the associations between self-injurious behaviours and externalizing psychopathology. An additional aim was to review terminology and measurements of self-injurious behaviour and the connection between self-injurious behaviours and suicide in the included publications. A systematic literature search was conducted on 31st December 2016 in five databases (PubMed, OVID Medline, OVID PsycINFO, Scopus, Web of Science) with two categories of search terms (1. nonsuicidal self-injury, non-suicidal self-injury, NSSI, self-injurious behaviour, SIB, deliberate self-harm, DSH, self-injury; 2. externalizing disorder, attention deficit hyperactivity disorder, ADHD, conduct disorder, CD, oppositional defiant disorder, OD, ODD). Finally 35 papers were included. Eleven different terms were found for describing self-injurious behaviours and 20 methods for measuring it. NSSI has the clearest definition. All the examined externalizing psychopathologies had strong associations with self-injurious behaviours according to: higher prevalence rates in externalizing groups than in control groups, higher externalizing scores on the externalizing scales of questionnaires, higher symptom severity in self-injurious groups. Eight studies investigated the relationship between suicide and self-injurious behaviours and found high overlap between the two phenomena and similar risk factors. Based on the current findings the association between externalizing psychopathology and self-injurious behaviours has been proven by the scientific literature. Similarly to other reviews on self-injurious behaviours the confusion in terminology and methodology was noticed. NSSI is suggested for use as a distinct term. Further studies should investigate the role of comorbid conditions in NSSI, especially when internalizing

  19. Constraints on the nature of the ancient lunar magnetic field

    International Nuclear Information System (INIS)

    Goswami, J.N.

    1976-01-01

    It is stated that many lunar rocks possess a stable component of natural remanent magnetisation with specific intensities of about 10 -6 emu/gm. Most of these rocks also have compaction ages > 3 x 10 9 yr. Ancient lunar surface magnetic fields of the order of 10 -2 to 1.2 gauss have been postulated to explain the observed remanent magnetisation, and interesting suggestions have been made concerning the origin of such high magnetic fields during the early history of the Moon. It has been proposed that an intrinsic dipolar field was acquired by the Moon during its initial stages of formation. Such a dipolar field could have resulted either from a primaeval magnetisation by an external field, or from the action of an ancient lunar dynamo. It is pointed out here that some constraints can be put on the origin and nature of the ancient lunar magnetic field by consideration of the observation of solar wind ions in lunar breccias with compaction ages > 3.2 x 10 9 yr. These observations rule out the hypothesis that external field magnetisation initiated the ancient lunar magnetic field. The lunar dynamo model is possible only if field reversal is introduced. (U.K.)

  20. Malignant external otitis in Spain.

    Science.gov (United States)

    Guerrero-Espejo, Antonio; Valenciano-Moreno, Inmaculada; Ramírez-Llorens, Rafael; Pérez-Monteagudo, Palmira

    Malignant external otitis is a necrotizing infection, which extends from the squamous epithelium of the ear canal to the adjacent tissue. The objective of the study was to investigate its incidence and other epidemiological data in Spain, reporting the largest case series to date. A descriptive, retrospective study of the Spanish population was carried out using the minimum basic data set (MBDS) based on data of patients admitted to hospitals in the 2008-2013 period. Patients whose diagnosis (principal or secondary) at discharge was encoded as 380.14 (malignant external otitis), according to ICD-9-CM, were included as cases. The Spanish incidence rate was calculated for all its communities and provinces, as well as by season and mortality. A total of 355 patients (302 as principal diagnosis and 53 as secondary) were diagnosed. The incidence rate was 1.30 (95% CI, 1.17 to 1.44) per 106 inhabitants and year, although there were variations among geographical areas. The median age of cases with main diagnosis was 74 years (range 10-95 years). The predominant age group was in patients over 84 years old (19.3 cases per 10 6 inhabitants and year). The incidence was higher in men and the male-female relative risk was 2.4. Diabetes was present in 74.6% of patients. The diagnosis was predominant in the last quarter of the year. The gross in-hospital mortality rate was 3.7%. Malignant external otitis is seen mostly among male elderly and diabetic patients. The incidence and mortality rate are low in Spain. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Slovenia’s Foreign Policy Opportunities and Constraints: The Analysis of an Interplay of Foreign Policy Environments

    Directory of Open Access Journals (Sweden)

    Fenko Ana Bojinović

    2017-09-01

    Full Text Available The article focuses on the interconnectedness of foreign policy environments to explain Slovenia’s opportunities and constraints for foreign policy action. During the period of pre-independence para-diplomacy, the building of an internal and external domestic environment successfully turned constraints (no international recognition into opportunities (applying for membership of European and global intergovernmental organizations. In the second period - post-recognition - considering the absence of a strategic foreign policy document, the Slovenian internal foreign policy environment became a major constraint to seize foreign environment opportunities. This affected Slovenia’s accomplishments, notably after NATO and EU memberships were achieved in 2004. Although the Slovenian internal environment matured during the following period to adopt, in 2015, a comprehensive foreign policy strategy the recent turn in world politics (especially the European financial and economic crisis and the migration crisis created for the first time a foreign environment for Slovenia that offered many fewer opportunities and far more constraints.

  3. Skepticism, Contextualism, Externalism and Modality

    Directory of Open Access Journals (Sweden)

    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.

  4. Some new external flavonoids from American ferns

    Energy Technology Data Exchange (ETDEWEB)

    Wollenweber, E.

    1979-01-01

    American gymnogrammoid ferns have been analysed for the flavonoid aglycones present in frond exudates. They are predominantly methylated chalcones, dihydrochalcones, flavones, and flavonols, occurring mostly as farinose deposit (''ceraceous indument''). This is the first report of external flavonoids on Pterozonium species; a chalcone has been identified. On Cheilanthes kaulfussii and Cheilanthes viscida traces of flavonoid aglycones are observed, dissolved in lipophilic exudate material. On Pellaea longimucronata a flavonol is found even on leaves which appear glaucous. 2',4',6'-Trihydroxychalcone is found for the second time in the plant kingdom on Adiantum sulphureum. Galangin-3,7-dimethylether is found as a new natural flavonol on Cheilanthes kaulfussii. In addition, samples of Pityrogramma chrysoconia and Pit. triangularis var. maxonii have been investigated. The results indicate chemotaxonomic implication of flavonoid patterns.

  5. Waveguide based external cavity semiconductor lasers

    NARCIS (Netherlands)

    Oldenbeuving, Ruud; Klein, E.J.; Offerhaus, Herman L.; Lee, Christopher James; Verhaegen, M.; Boller, Klaus J.

    2012-01-01

    We report on progress of the project waveguide based external cavity semiconductor laser (WECSL) arrays. Here we present the latest results on our efforts to mode lock an array of tunable, external cavity semiconductor lasers.

  6. Constraint theory multidimensional mathematical model management

    CERN Document Server

    Friedman, George J

    2017-01-01

    Packed with new material and research, this second edition of George Friedman’s bestselling Constraint Theory remains an invaluable reference for all engineers, mathematicians, and managers concerned with modeling. As in the first edition, this text analyzes the way Constraint Theory employs bipartite graphs and presents the process of locating the “kernel of constraint” trillions of times faster than brute-force approaches, determining model consistency and computational allowability. Unique in its abundance of topological pictures of the material, this book balances left- and right-brain perceptions to provide a thorough explanation of multidimensional mathematical models. Much of the extended material in this new edition also comes from Phan Phan’s PhD dissertation in 2011, titled “Expanding Constraint Theory to Determine Well-Posedness of Large Mathematical Models.” Praise for the first edition: "Dr. George Friedman is indisputably the father of the very powerful methods of constraint theory...

  7. New cosmological constraints on primordial black holes

    International Nuclear Information System (INIS)

    Carr, B. J.; Kohri, Kazunori; Sendouda, Yuuiti; Yokoyama, Jun'ichi

    2010-01-01

    We update the constraints on the fraction of the Universe going into primordial black holes in the mass range 10 9 -10 17 g associated with the effects of their evaporations on big bang nucleosynthesis and the extragalactic photon background. We include for the first time all the effects of quark and gluon emission by black holes on these constraints and account for the latest observational developments. We then discuss the other constraints in this mass range and show that these are weaker than the nucleosynthesis and photon background limits, apart from a small range 10 13 -10 14 g, where the damping of cosmic microwave background anisotropies dominates. Finally we review the gravitational and astrophysical effects of nonevaporating primordial black holes, updating constraints over the broader mass range 1-10 50 g.

  8. Constraints Faced by m-Kisan Users

    Directory of Open Access Journals (Sweden)

    M. Jayanthi

    2016-11-01

    Full Text Available The study focused on constraints faced by m-Kisan users while availing mobile agricultural extension service. Data were derived from 120 m-Kisan users in two districts of Tamil Nadu state.

  9. Constraints To Farmers Effective Participation In Agricultural ...

    African Journals Online (AJOL)

    eastern Nigeria is the provision of agricultural extension services to farmers. This study, therefore, examined the constraints to farmers' effective participation in the agricultural extension programmes of four non-profit NGOs in three states of ...

  10. Modernizing China's Military: Opportunities and Constraints

    National Research Council Canada - National Science Library

    Crane, Keith; Cliff, Roger; Medeiros, Evan; Mulvenon, James; Overholt, William

    2005-01-01

    The purpose of this study is to assess future resource constraints on, and potential domestic economic and industrial contributions to, the ability of the Chinese military to become a significant threat to U.S. forces by 2025...

  11. Dynamic shortfall constraints for optimal portfolios

    Directory of Open Access Journals (Sweden)

    Bernd Luderer

    2010-06-01

    Full Text Available We consider a portfolio problem when a Tail Conditional Expectation constraint is imposed. The financial market is composed of n risky assets driven by geometric Brownian motion and one risk-free asset. The Tail Conditional Expectation is calculated for short intervals of time and imposed as risk constraint dynamically. The method of Lagrange multipliers is combined with the Hamilton-Jacobi-Bellman equation to insert the constraint into the resolution framework. A numerical method is applied to obtain an approximate solution to the problem. We find that the imposition of the Tail Conditional Expectation constraint when risky assets evolve following a log-normal distribution, curbs investment in the risky assets and diverts the wealth to consumption.

  12. Optimal portfolio strategies under a shortfall constraint

    Directory of Open Access Journals (Sweden)

    D Akuma

    2009-06-01

    Full Text Available We impose dynamically, a shortfall constraint in terms of Tail Conditional Expectation on the portfolio selection problem in continuous time, in order to obtain optimal strategies. The financial market is assumed to comprise n risky assets driven by geometric Brownian motion and one risk-free asset. The method of Lagrange multipliers is combined with the Hamilton-Jacobi-Bellman equation to insert the constraint into the resolution framework. The constraint is re-calculated at short intervals of time throughout the investment horizon. A numerical method is applied to obtain an approximate solution to the problem. It is found that the imposition of the constraint curbs investment in the risky assets.

  13. Biological constraints do not entail cognitive closure.

    Science.gov (United States)

    Vlerick, Michael

    2014-12-01

    From the premise that our biology imposes cognitive constraints on our epistemic activities, a series of prominent authors--most notably Fodor, Chomsky and McGinn--have argued that we are cognitively closed to certain aspects and properties of the world. Cognitive constraints, they argue, entail cognitive closure. I argue that this is not the case. More precisely, I detect two unwarranted conflations at the core of arguments deriving closure from constraints. The first is a conflation of what I will refer to as 'representation' and 'object of representation'. The second confuses the cognitive scope of the assisted mind for that of the unassisted mind. Cognitive closure, I conclude, cannot be established from pointing out the (uncontroversial) existence of cognitive constraints. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Backstepping control for a 3DOF model helicopter with input and output constraints

    Directory of Open Access Journals (Sweden)

    Rong Mei

    2016-02-01

    Full Text Available In this article, a backstepping control scheme is developed for the motion control of a Three degrees of freedom (3DOF model helicopter with unknown external disturbance, modelling uncertainties and input and output constraints. In the developed robust control scheme, augmented state observers are applied to estimate the unknown states, unknown external disturbance and modelling uncertainties. Auxiliary systems are designed to deal with input saturation. A barrier Lyapunov function is employed to handle the output saturation. The stability of closed-loop system is proved by the Lyapunov method. Simulation results show that the designed control scheme is effective at dealing with the motion control of a 3DOF model helicopter in the presence of unknown external disturbance and modelling uncertainties, and input and output saturation.

  15. Equilibrium Statistical Thermodynamics of a Many-Particle System Coupled to an External Scalar Field

    Science.gov (United States)

    Salvino, R. E.

    1990-01-01

    The equilibrium thermodynamics of a many-particle assembly in the presence of an external scalar field is examined. Two types of scalar coupling are considered: an external field coupled to the particle density and an external scalar field coupled to the energy density. It is shown that the broken translational and rotational invariance of the system due to the external field is reflected in the macroscopic physics by loss of the usual extensivity property of the system and by means of anisotropy in the response of the system to changes in the system lengths or to the system shape. In addition, the assumptions used in local equilibrium analyses are shown to be incorrect in principle. Nonlocal effects due to the external field must be included in the determination of the equation of state. Simple model calculations for a system in an external gravitational field and an externally imposed temperature field are presented as illustrations.

  16. Portfolios with nonlinear constraints and spin glasses

    Science.gov (United States)

    Gábor, Adrienn; Kondor, I.

    1999-12-01

    In a recent paper Galluccio, Bouchaud and Potters demonstrated that a certain portfolio problem with a nonlinear constraint maps exactly onto finding the ground states of a long-range spin glass, with the concomitant nonuniqueness and instability of the optimal portfolios. Here we put forward geometric arguments that lead to qualitatively similar conclusions, without recourse to the methods of spin glass theory, and give two more examples of portfolio problems with convex nonlinear constraints.

  17. Firm Heterogeneity, Credit Constraints, and Endogenous Growth

    OpenAIRE

    Torben Klarl; Alfred Maussner

    2010-01-01

    This paper is concerned with the role of firm heterogeneity under credit constraints for economic growth. We focus on firm size, innovativeness and credit constraints in a semi-endogenous growth model reflecting recent empirical findings on firm heterogeneity. It allows for an explicit solution for transitional growth and balanced growth path productivity as well as the growth maximizing firm heterogeneity. This enables us to draw inference about the impact of key policy parameters of the mod...

  18. University Course Timetabling using Constraint Programming

    Directory of Open Access Journals (Sweden)

    Hadi Shahmoradi

    2017-03-01

    Full Text Available University course timetabling problem is a challenging and time-consuming task on the overall structure of timetable in every academic environment. The problem deals with many factors such as the number of lessons, classes, teachers, students and working time, and these are influenced by some hard and soft constraints. The aim of solving this problem is to assign courses and classes to teachers and students, so that the restrictions are held. In this paper, a constraint programming method is proposed to satisfy maximum constraints and expectation, in order to address university timetabling problem. For minimizing the penalty of soft constraints, a cost function is introduced and AHP method is used for calculating its coefficients. The proposed model is tested on department of management, University of Isfahan dataset using OPL on the IBM ILOG CPLEX Optimization Studio platform. A statistical analysis has been conducted and shows the performance of the proposed approach in satisfying all hard constraints and also the satisfying degree of the soft constraints is on maximum desirable level. The running time of the model is less than 20 minutes that is significantly better than the non-automated ones.

  19. 46 CFR 64.19 - External pressure.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false External pressure. 64.19 Section 64.19 Shipping COAST... HANDLING SYSTEMS Standards for an MPT § 64.19 External pressure. (a) A tank without a vacuum breaker must be designed to withstand an external pressure of 71/2 psig or more. (b) A tank with a vacuum breaker...

  20. 49 CFR 195.108 - External pressure.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External pressure. 195.108 Section 195.108 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Design Requirements § 195.108 External pressure. Any external pressure that will be exerted on the...

  1. 46 CFR 154.452 - External pressure.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false External pressure. 154.452 Section 154.452 Shipping... Independent Tank Type C and Process Pressure Vessels § 154.452 External pressure. The design external pressure...) for tanks without a vacuum relief valve. P2=0, or the pressure relief valve setting for an enclosed...

  2. 187 AGRICULTURAL GROWTH AND EXTERNAL DEBT ...

    African Journals Online (AJOL)

    Agricultural revenue has not been able to sustain the external debt in. Nigeria despite the effort ... increasing external debt volume while real private investment expenditure decreases with .... results. Ehirim, N. C. Agricultural growth and External debt management in developing nations: Evidence from Nigeria (1960-. 2005) ...

  3. Additive Manufacturing Infrared Inspection

    Science.gov (United States)

    Gaddy, Darrell; Nettles, Mindy

    2015-01-01

    The Additive Manufacturing Infrared Inspection Task started the development of a real-time dimensional inspection technique and digital quality record for the additive manufacturing process using infrared camera imaging and processing techniques. This project will benefit additive manufacturing by providing real-time inspection of internal geometry that is not currently possible and reduce the time and cost of additive manufactured parts with automated real-time dimensional inspections which deletes post-production inspections.

  4. External-stimuli responsive systems for cancer theranostic

    Directory of Open Access Journals (Sweden)

    Jianhui Yao

    2016-10-01

    Full Text Available The upsurge of novel nanomaterials and nanotechnologies has inspired the researchers who are striving for designing safer and more efficient drug delivery systems for cancer therapy. Stimuli responsive nanomaterial offered an alternative to design controllable drug delivery system on account of its spatiotemporally controllable properties. Additionally, external stimuli (light, magnetic field and ultrasound could develop into theranostic applications for personalized medicine use because of their unique characteristics. In this review, we give a brief overview about the significant progresses and challenges of certain external-stimuli responsive systems that have been extensively investigated in drug delivery and theranostics within the last few years.

  5. Constraint-Muse: A Soft-Constraint Based System for Music Therapy

    Science.gov (United States)

    Hölzl, Matthias; Denker, Grit; Meier, Max; Wirsing, Martin

    Monoidal soft constraints are a versatile formalism for specifying and solving multi-criteria optimization problems with dynamically changing user preferences. We have developed a prototype tool for interactive music creation, called Constraint Muse, that uses monoidal soft constraints to ensure that a dynamically generated melody harmonizes with input from other sources. Constraint Muse provides an easy to use interface based on Nintendo Wii controllers and is intended to be used in music therapy for people with Parkinson’s disease and for children with high-functioning autism or Asperger’s syndrome.

  6. External noise when using biofuel

    International Nuclear Information System (INIS)

    Kotaleski, J.

    1994-08-01

    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

  7. [Food additives and healthiness].

    Science.gov (United States)

    Heinonen, Marina

    2014-01-01

    Additives are used for improving food structure or preventing its spoilage, for example. Many substances used as additives are also naturally present in food. The safety of additives is evaluated according to commonly agreed principles. If high concentrations of an additive cause adverse health effects for humans, a limit of acceptable daily intake (ADI) is set for it. An additive is a risk only when ADI is exceeded. The healthiness of food is measured on the basis of nutrient density and scientifically proven effects.

  8. Cosmological constraints on interacting light particles

    Energy Technology Data Exchange (ETDEWEB)

    Brust, Christopher [Perimeter Institute for Theoretical Physics, 31 Caroline Street N, Waterloo, ON, N2L 2Y5 Canada (Canada); Cui, Yanou [Department of Physics and Astronomy, University of California, 900 University Ave, Riverside, CA, 92521 (United States); Sigurdson, Kris, E-mail: cbrust@perimeterinstitute.ca, E-mail: yanou.cui@ucr.edu, E-mail: krs@phas.ubc.ca [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC, V6T 1Z1 Canada (Canada)

    2017-08-01

    Cosmological observations are becoming increasingly sensitive to the effects of light particles in the form of dark radiation (DR) at the time of recombination. The conventional observable of effective neutrino number, N {sub eff}, is insufficient for probing generic, interacting models of DR. In this work, we perform likelihood analyses which allow both free-streaming effective neutrinos (parametrized by N {sub eff}) and interacting effective neutrinos (parametrized by N {sub fld}). We motivate an alternative parametrization of DR in terms of N {sub tot} (total effective number of neutrinos) and f {sub fs} (the fraction of effective neutrinos which are free-streaming), which is less degenerate than using N {sub eff} and N {sub fld}. Using the Planck 2015 likelihoods in conjunction with measurements of baryon acoustic oscillations (BAO), we find constraints on the total amount of beyond the Standard Model effective neutrinos (both free-streaming and interacting) of Δ N {sub tot} < 0.39 at 2σ. In addition, we consider the possibility that this scenario alleviates the tensions between early-time and late-time cosmological observations, in particular the measurements of σ{sub 8} (the amplitude of matter power fluctuations at 8 h {sup −1} Mpc), finding a mild preference for interactions among light species. We further forecast the sensitivities of a variety of future experiments, including Advanced ACTPol (a representative CMB Stage-III experiment), CMB Stage-IV, and the Euclid satellite. This study is relevant for probing non-standard neutrino physics as well as a wide variety of new particle physics models beyond the Standard Model that involve dark radiation.

  9. Observational constraints on generalized Proca theories

    Science.gov (United States)

    De Felice, Antonio; Heisenberg, Lavinia; Tsujikawa, Shinji

    2017-06-01

    In a model of the late-time cosmic acceleration within the framework of generalized Proca theories, there exists a de Sitter attractor preceded by the dark energy equation of state wDE=-1 -s , where s is a positive constant. We run the Markov-chain-Monte Carlo code to confront the model with the observational data of the cosmic microwave background (CMB), baryon acoustic oscillations, supernovae type Ia, and local measurements of the Hubble expansion rate for the background cosmological solutions and obtain the bound s =0.254-0.097+0.118 at 95% confidence level (C.L.). Existence of the additional parameter s to those in the Λ -cold-dark-matter (Λ CDM ) model allows to reduce tensions of the Hubble constant H0 between the CMB and the low-redshift measurements. Including the cosmic growth data of redshift-space distortions in the galaxy power spectrum and taking into account no-ghost and stability conditions of cosmological perturbations, we find that the bound on s is shifted to s =0.1 6-0.08+0.08 (95% C.L.) and hence the model with s >0 is still favored over the Λ CDM model. Apart from the quantities s ,H0 and the today's matter density parameter Ωm 0, the constraints on other model parameters associated with perturbations are less stringent, reflecting the fact that there are different sets of parameters that give rise to a similar cosmic expansion and growth history.

  10. Time constraints in the alcohol purchase task.

    Science.gov (United States)

    Kaplan, Brent A; Reed, Derek D; Murphy, James G; Henley, Amy J; Reed, Florence D DiGennaro; Roma, Peter G; Hursh, Steven R

    2017-06-01

    Hypothetical purchase tasks have advanced behavioral economic evaluations of demand by circumventing practical and ethical restrictions associated with delivering drug reinforcers to participants. Numerous studies examining the reliability and validity of purchase task methodology suggest that it is a valuable method for assessing demand that warrants continued use and evaluation. Within the literature examining purchase tasks, the alcohol purchase task (APT) has received the most investigation, and currently represents the most experimentally validated variant. However, inconsistencies in purchase task methodology between studies exist, even within APT studies, and, to date, none have assessed the influence of experimental economic constraints on responding. This study examined changes in Q0 (reported consumption when drinks are free), breakpoint (price that suppresses consumption), and α (rate of change in demand elasticity) in the presence of different hypothetical durations of access to alcohol in an APT. One hundred seventy-nine participants (94 males, 85 females) from Amazon Mechanical Turk completed 3 APTs that varied in the duration of time at a party (i.e., access to alcoholic beverages) as described in the APT instructions (i.e., vignette). The 3 durations included 5-hr (used by Murphy et al., 2013), 1-hr, and 9-hr time frames. We found that hypothetical duration of access was significantly related to Q0 and breakpoint at the individual level. Additionally, group-level mean α decreased significantly with increases in duration of access, thus indicating relatively higher demand for alcohol with longer durations of access. We discuss implications for conducting hypothetical purchase task research and alcohol misuse prevention efforts. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  11. Laboratory constraints on models of earthquake recurrence

    Science.gov (United States)

    Beeler, Nicholas M.; Tullis, Terry; Junger, Jenni; Kilgore, Brian D.; Goldsby, David L.

    2014-01-01

    In this study, rock friction ‘stick-slip’ experiments are used to develop constraints on models of earthquake recurrence. Constant-rate loading of bare rock surfaces in high quality experiments produces stick-slip recurrence that is periodic at least to second order. When the loading rate is varied, recurrence is approximately inversely proportional to loading rate. These laboratory events initiate due to a slip rate-dependent process that also determines the size of the stress drop [Dieterich, 1979; Ruina, 1983] and as a consequence, stress drop varies weakly but systematically with loading rate [e.g., Gu and Wong, 1991; Karner and Marone, 2000; McLaskey et al., 2012]. This is especially evident in experiments where the loading rate is changed by orders of magnitude, as is thought to be the loading condition of naturally occurring, small repeating earthquakes driven by afterslip, or low-frequency earthquakes loaded by episodic slip. As follows from the previous studies referred to above, experimentally observed stress drops are well described by a logarithmic dependence on recurrence interval that can be cast as a non-linear slip-predictable model. The fault’s rate dependence of strength is the key physical parameter. Additionally, even at constant loading rate the most reproducible laboratory recurrence is not exactly periodic, unlike existing friction recurrence models. We present example laboratory catalogs that document the variance and show that in large catalogs, even at constant loading rate, stress drop and recurrence co-vary systematically. The origin of this covariance is largely consistent with variability of the dependence of fault strength on slip rate. Laboratory catalogs show aspects of both slip and time predictability and successive stress drops are strongly correlated indicating a ‘memory’ of prior slip history that extends over at least one recurrence cycle.

  12. Additive manufacturing of RF absorbers

    Science.gov (United States)

    Mills, Matthew S.

    The ability of additive manufacturing techniques to fabricate integrated electromagnetic absorbers tuned for specific radio frequency bands within structural composites allows for unique combinations of mechanical and electromagnetic properties. These composites and films can be used for RF shielding of sensitive electromagnetic components through in-plane and out-of-plane RF absorption. Structural composites are a common building block of many commercial platforms. These platforms may be placed in situations in which there is a need for embedded RF absorbing properties along with structural properties. Instead of adding radar absorbing treatments to the external surface of existing structures, which adds increased size, weight and cost; it could prove to be advantageous to integrate the microwave absorbing properties directly into the composite during the fabrication process. In this thesis, a method based on additive manufacturing techniques of composites structures with prescribed electromagnetic loss, within the frequency range 1 to 26GHz, is presented. This method utilizes screen printing and nScrypt micro dispensing to pattern a carbon based ink onto low loss substrates. The materials chosen for this study will be presented, and the fabrication technique that these materials went through to create RF absorbing structures will be described. The calibration methods used, the modeling of the RF structures, and the applications in which this technology can be utilized will also be presented.

  13. Quantitative Assessment of Thermodynamic Constraints on the Solution Space of Genome-Scale Metabolic Models

    Science.gov (United States)

    Hamilton, Joshua J.; Dwivedi, Vivek; Reed, Jennifer L.

    2013-01-01

    Constraint-based methods provide powerful computational techniques to allow understanding and prediction of cellular behavior. These methods rely on physiochemical constraints to eliminate infeasible behaviors from the space of available behaviors. One such constraint is thermodynamic feasibility, the requirement that intracellular flux distributions obey the laws of thermodynamics. The past decade has seen several constraint-based methods that interpret this constraint in different ways, including those that are limited to small networks, rely on predefined reaction directions, and/or neglect the relationship between reaction free energies and metabolite concentrations. In this work, we utilize one such approach, thermodynamics-based metabolic flux analysis (TMFA), to make genome-scale, quantitative predictions about metabolite concentrations and reaction free energies in the absence of prior knowledge of reaction directions, while accounting for uncertainties in thermodynamic estimates. We applied TMFA to a genome-scale network reconstruction of Escherichia coli and examined the effect of thermodynamic constraints on the flux space. We also assessed the predictive performance of TMFA against gene essentiality and quantitative metabolomics data, under both aerobic and anaerobic, and optimal and suboptimal growth conditions. Based on these results, we propose that TMFA is a useful tool for validating phenotypes and generating hypotheses, and that additional types of data and constraints can improve predictions of metabolite concentrations. PMID:23870272

  14. Observational constraints on gauge field production in axion inflation

    International Nuclear Information System (INIS)

    Meerburg, P.D.; Pajer, E.

    2013-01-01

    Models of axion inflation are particularly interesting since they provide a natural justification for the flatness of the potential over a super-Planckian distance, namely the approximate shift-symmetry of the inflaton. In addition, most of the observational consequences are directly related to this symmetry and hence are correlated. Large tensor modes can be accompanied by the observable effects of a the shift-symmetric coupling φF F-tilde to a gauge field. During inflation this coupling leads to a copious production of gauge quanta and consequently a very distinct modification of the primordial curvature perturbations. In this work we compare these predictions with observations. We find that the leading constraint on the model comes from the CMB power spectrum when considering both WMAP 7-year and ACT data. The bispectrum generated by the non-Gaussian inverse-decay of the gauge field leads to a comparable but slightly weaker constraint. There is also a constraint from μ-distortion using TRIS plus COBE/FIRAS data, but it is much weaker. Finally we comment on a generalization of the model to massive gauge fields. When the mass is generated by some light Higgs field, observably large local non-Gaussianity can be produced

  15. Ring-Constraint High-Pressure Torsion Process

    Science.gov (United States)

    Joo, Soo-Hyun; Kim, Hyoung Seop

    2016-07-01

    In this study, a constraint ring around a workpiece was employed in order to develop back pressure in addition to a compressive die pressure in high-pressure torsion (HPT) process. The influence of the constraint ring during the HPT process was analyzed using the finite element method and experimental analyses. Greater back pressure was developed when a ring of a stronger material enveloped the workpiece. In the experiments, fracture of a brittle material [ e.g., La-based bulk metallic glass (BMG)], was limited even at large shear strain (~315) during the ring-constraint HPT (RC-HPT) process due to reduced tensile stress at the edge of the deforming BMG workpiece. Furthermore, the RC-HPT process had beneficial effects on powder consolidation and bonding. The RC-HPT process exhibited smaller loss of material than did the conventional semi-constrained HPT process. The Cu disk produced by the powder RC-HPT had smaller grain sizes because back pressure generated more dislocations and finer grain size in the Cu workpiece.

  16. Task constraints modulate activation in right ventral lateral prefrontal cortex.

    Science.gov (United States)

    Vartanian, Oshin; Goel, Vinod

    2005-10-01

    Lesion data suggest that right prefrontal cortex (PFC) plays a critical role in open-ended problem solving. To test this hypothesis, we scanned fifteen normal subjects with fMRI as they completed three types of anagram problems varying in the level of constraints placed on the search space. On unconstrained trials, they rearranged letters to generate solutions (e.g., Can you make a "Word with ZJAZ?"). On semantically constrained trials, they rearranged letters to generate solutions within particular semantic categories (e.g., Can you make a type of "Music with ZJAZ?"). On baseline trials, they rearranged letters to make specific words (e.g., Can you make the word "JAZZ with ZJAZ?"). As predicted, the critical comparison of unconstrained vs. semantically constrained trials revealed significant activation in right ventral lateral PFC, as well as left superior frontal gyrus, frontopolar cortex, right superior parietal lobe, right post central gyrus, and the occipital-parietal sulcus. Furthermore, activation in right ventral lateral PFC (BA 47) increased as the constraints placed on the anagram search space were reduced. We argue that the activation in right ventral lateral PFC is related to hypothesis generation in unconstrained settings, whereas activation in other structures is related to additional processes linked to anagram problems such as semantic retrieval, semantic categorization, and cognitive monitoring. These results extend the lesion data and imaging studies by demonstrating that a relative absence of constraints on the solution space is sufficient to engage right ventral lateral PFC in hypothesis generation tasks.

  17. Constraints and entropy in a model of network evolution

    Science.gov (United States)

    Tee, Philip; Wakeman, Ian; Parisis, George; Dawes, Jonathan; Kiss, István Z.

    2017-11-01

    Barabási-Albert's "Scale Free" model is the starting point for much of the accepted theory of the evolution of real world communication networks. Careful comparison of the theory with a wide range of real world networks, however, indicates that the model is in some cases, only a rough approximation to the dynamical evolution of real networks. In particular, the exponent γ of the power law distribution of degree is predicted by the model to be exactly 3, whereas in a number of real world networks it has values between 1.2 and 2.9. In addition, the degree distributions of real networks exhibit cut offs at high node degree, which indicates the existence of maximal node degrees for these networks. In this paper we propose a simple extension to the "Scale Free" model, which offers better agreement with the experimental data. This improvement is satisfying, but the model still does not explain why the attachment probabilities should favor high degree nodes, or indeed how constraints arrive in non-physical networks. Using recent advances in the analysis of the entropy of graphs at the node level we propose a first principles derivation for the "Scale Free" and "constraints" model from thermodynamic principles, and demonstrate that both preferential attachment and constraints could arise as a natural consequence of the second law of thermodynamics.

  18. Complexities and constraints influencing learner performance in physical science

    Directory of Open Access Journals (Sweden)

    Mavhungu Abel Mafukata

    2016-01-01

    Full Text Available This paper explores complexities and constraints affecting performance and output of physical science learners in Vhembe District, Limpopo Province, South Africa. The study was motivated by the desire of the researcher to establish, profile and characterise the complexities and constraints reminiscence of poor performance of learners in physical science as measured through end-of-year Grade 12 (final year of high school education examination results. Twenty six schools (n=26 were purposively selected from three circuits of education (n=3. From these schools, two learners were randomly selected (n=52 for interviews. In addition, two circuit managers (n=2 were conveniently selected as part of Key Informant Interviews (KII. For the Focus Group Discussions (FGDs, twelve (n=12 parents were randomly selected to form two groups of six members each. Multi-factor complexities and constraints impeding performance of learners were discovered. Intensive teacher in-service programme is recommended. Community engagement should be encouraged to educate parents on the value of involvement in the education of their children. Free access learner support structures such as Homework and Extra-lessons Assistance Centre (H&EACs should be established.

  19. Leveraging External Sources of Innovation

    DEFF Research Database (Denmark)

    West, Joel; Bogers, Marcel

    2014-01-01

    suggests several gaps in prior research. One is a tendency to ignore the importance of business models, despite their central role in distinguishing open innovation from earlier research on interorganizational collaboration in innovation. Another gap is a tendency in open innovation to use “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...... cited work beyond those journals. A review of 291 open innovation-related publications from these sources shows that the majority of these articles indeed address elements of this inbound open innovation process model. Specifically, it finds that researchers have front-loaded their examination...

  20. External radiotherapy in thyroid cancer

    International Nuclear Information System (INIS)

    Samuel, A.M.; Shah, D.H.

    1999-01-01

    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 ( 131 I), especially, when the tumor has the ability to concentrate 131 I. 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

  1. Effects of External Loads on Human Head Movement Control Systems

    Science.gov (United States)

    Nam, M. H.; Choi, O. M.

    1984-01-01

    The central and reflexive control strategies underlying movements were elucidated by studying the effects of external loads on human head movement control systems. Some experimental results are presented on dynamic changes weigh the addition of aviation helmet (SPH4) and lead weights (6 kg). Intended time-optimal movements, their dynamics and electromyographic activity of neck muscles in normal movements, and also in movements made with external weights applied to the head were measured. It was observed that, when the external loads were added, the subject went through complex adapting processes and the head movement trajectory and its derivatives reached steady conditions only after transient adapting period. The steady adapted state was reached after 15 to 20 seconds (i.e., 5 to 6 movements).

  2. Analysis of External Treatment Methods and Technical Characteristics of External Treatment

    Science.gov (United States)

    Zhang, Rui; Miao, Mingsan; Bai, Ming

    2018-01-01

    Chinese medicine external therapy is a treatment method of Chinese medicine with Chinese characteristics. The effect of traditional Chinese medicine external treatment, convenient operation, external treatment and technology has great prospects for development. The traditional Chinese medicine external treatment method and technical characteristics were analyzed.

  3. Corporal Punishment and Youth Externalizing Behavior in Santiago, Chile

    Science.gov (United States)

    Ma, Julie; Han, Yoonsun; Grogan-Kaylor, Andrew; Delva, Jorge; Castillo, Marcela

    2012-01-01

    Objectives Corporal punishment is still widely practiced around the globe, despite the large body of child development research that substantiates its short- and long-term consequences. Within this context, this paper examined the relationship between parental use of corporal punishment and youth externalizing behavior with a Chilean sample to add to the growing empirical evidence concerning the potential relationship between increased corporal punishment and undesirable youth outcomes across cultures. Methods Analysis was based on 919 adolescents in Santiago, Chile. Descriptive and multivariate analyses were conducted to examine the extent to which parents’ use of corporal punishment and positive family measures were associated with youth externalizing behavior. Furthermore, the associations between self-reported externalizing behavior and infrequent, as well as frequent, use of corporal punishment were investigated to contribute to understanding how varying levels of parental use of corporal punishment were differently related to youth outcomes. Results Both mother’s and father’s use of corporal punishment were associated with greater youth externalizing behavior. Additionally, increases in positive parenting practices, such as parental warmth and family involvement, were met with decreases in youth externalizing behavior when controlling for youth demographics, family socioeconomic status, and parents’ use of corporal punishment. Finally, both infrequent and frequent use of corporal punishment were positively associated with higher youth problem behaviors, though frequent corporal punishment had a stronger relationship with externalizing behavior than did infrequent corporal punishment. Conclusions Parental use of corporal punishment, even on an occasional basis, is associated with greater externalizing behavior for youth while a warm and involving family environment may protect youth from serious problem behaviors. Therefore, findings of this study add

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

    International Nuclear Information System (INIS)

    Markandya, A.

    1994-01-01

    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

  5. Additives in yoghurt production

    Directory of Open Access Journals (Sweden)

    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.

  6. Correlations between internal and external power outputs during weightlifting exercise.

    Science.gov (United States)

    Kipp, Kristof; Harris, Chad; Sabick, Michelle B

    2013-04-01

    Identifying loads that maximize mechanical power is important because training at such loads may optimize gains in dynamic athletic performance. The purpose of this study was to examine correlations between measures of external mechanical power output and internal mechanical joint power output across different loads during a weightlifting exercise. Ten subjects performed 3 sets of the clean exercise at 65, 75, and 85% of 1 repetition maximum (1RM). Peak external mechanical power output was calculated with 4 commonly used methods, whereas an inverse dynamics approach was used to calculate peak internal mechanical power output for the hip, knee, and ankle joints along with the peak of the sum of all internal joint powers. All peak mechanical power outputs were expressed as relative peak power by either ratio (watts per kilogram) or allometrically scaling to body mass (W·kg). Correlation coefficients were used to compare power output measures. The greatest numbers of significant correlations between internal and external power outputs were observed at 85% of 1RM, at this load hip and knee joint power outputs were correlated to external mechanical power output when calculated with the traditional work-energy method. In addition, the peak sum of all mechanical joint powers was correlated to mechanical power output when calculated with the impulse-momentum method at loads of 75 and 85% of the 1RM. Allometric scaling of power outputs yielded one more significant correlation than did the ratio scaled power outputs. These findings support the use of the work-energy method when making inferences about internal joint powers from external power outputs when loads equal to 85% of 1RM are being lifted. In addition, the impulse-momentum method may be used to make inferences about the sum of all internal joint powers from external power outputs when loads between 75 and 85% of 1RM are being lifted.

  7. About External Geographic Information and Knowledge in Smart Cities

    Science.gov (United States)

    Laurinia, R.; Favetta, F.

    2017-09-01

    Any territory can easily be considered as an open system in which external effects can greatly influence its evolution in addition to inner dynamics. However, in practically all local authorities, their so-called geographic information or knowledge systems are bounded by the jurisdiction's limit, and therefore are closed systems. In this paper, we advocate the necessity not only to consider but also to include external influences within any GIS or GKS. Therefore, among external influences, we will consider beyond intra muros knowledge, extra muros knowledge divided in two categories, nearby neighboring knowledge, for instance located in an outer crown around the jurisdiction territory, but also farther knowledge for instance from technology watch. After having analyzed the semantics of borderlines, we suggest some element for the design of the crown and we analyze how the various components of a geographic knowledge base (objects, relations, ontologies, gazetteers, rules, etc.) can be integrated. Then some aspects regarding updating external knowledge are rapidly sketched. As a conclusion, we evoke the necessity of designing administrative protocols so that administration can negotiate the exchange of external knowledge bunches. In other words, this is an attempt to fully integrate the so-called Tobler's first law of geography.

  8. ABOUT EXTERNAL GEOGRAPHIC INFORMATION AND KNOWLEDGE IN SMART CITIES

    Directory of Open Access Journals (Sweden)

    R. Laurinia

    2017-09-01

    Full Text Available Any territory can easily be considered as an open system in which external effects can greatly influence its evolution in addition to inner dynamics. However, in practically all local authorities, their so-called geographic information or knowledge systems are bounded by the jurisdiction’s limit, and therefore are closed systems. In this paper, we advocate the necessity not only to consider but also to include external influences within any GIS or GKS. Therefore, among external influences, we will consider beyond intra muros knowledge, extra muros knowledge divided in two categories, nearby neighboring knowledge, for instance located in an outer crown around the jurisdiction territory, but also farther knowledge for instance from technology watch. After having analyzed the semantics of borderlines, we suggest some element for the design of the crown and we analyze how the various components of a geographic knowledge base (objects, relations, ontologies, gazetteers, rules, etc. can be integrated. Then some aspects regarding updating external knowledge are rapidly sketched. As a conclusion, we evoke the necessity of designing administrative protocols so that administration can negotiate the exchange of external knowledge bunches. In other words, this is an attempt to fully integrate the so-called Tobler’s first law of geography.

  9. Faddeev-Jackiw quantization and constraints

    Energy Technology Data Exchange (ETDEWEB)

    Barcelos-Neto, J.; Wotzasek, C. (Universidade Federal Rural do Rio de Janeiro, RJ (Brazil). Dept. de Fisica)

    1992-08-10

    In a recent Letter, Faddeev and Jackiw have shown that the reduction of constrained systems into its canonical, first-order form, can bring some new insight into the research of this field. For sympletic manifolds the geometrical structure, called Dirac or generalized bracket, is obtained directly from the inverse of the nonsingular sympletic two-form matrix. In the cases of nonsympletic manifolds, this two-form is degenerated and cannot be inverted to provide the generalized brackets. This singular behavior of the sympletic matrix is indicative of the presence of constraints that have to be carefully considered to yield to consistent results. One has two possible routes to treat this problem: Dirac has taught us how to implement the constraints into the potential part (Hamiltonian) of the canonical Lagrangian, leading to the well-known Dirac brackets, which are consistent with the constraints and can be mapped into quantum commutators (modulo ordering terms). The second route, suggested by Faddeev and Jackiw, and followed in this paper, is to implement the constraints directly into the canonical part of the first order Lagrangian, using the fact that the consistence condition for the stability of the constrained manifold is linear in the time derivative. This algorithm may lead to an invertible two-form sympletic matrix from where the Dirac brackets are readily obtained. This algorithm is used in this paper to investigate some aspects of the quantization of constrained systems with first- and second-class constraints in the sympletic approach.

  10. Pair Production Constraints on Superluminal Neutrinos Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; /SLAC; Gardner, Susan; /Kentucky U.

    2012-02-16

    We revisit the pair creation constraint on superluminal neutrinos considered by Cohen and Glashow in order to clarify which types of superluminal models are constrained. We show that a model in which the superluminal neutrino is effectively light-like can evade the Cohen-Glashow constraint. In summary, any model for which the CG pair production process operates is excluded because such timelike neutrinos would not be detected by OPERA or other experiments. However, a superluminal neutrino which is effectively lightlike with fixed p{sup 2} can evade the Cohen-Glashow constraint because of energy-momentum conservation. The coincidence involved in explaining the SN1987A constraint certainly makes such a picture improbable - but it is still intrinsically possible. The lightlike model is appealing in that it does not violate Lorentz symmetry in particle interactions, although one would expect Hughes-Drever tests to turn up a violation eventually. Other evasions of the CG constraints are also possible; perhaps, e.g., the neutrino takes a 'short cut' through extra dimensions or suffers anomalous acceleration in matter. Irrespective of the OPERA result, Lorentz-violating interactions remain possible, and ongoing experimental investigation of such possibilities should continue.

  11. Faddeev-Jackiw quantization and constraints

    International Nuclear Information System (INIS)

    Barcelos-Neto, J.; Wotzasek, C.

    1992-01-01

    In a recent Letter, Faddeev and Jackiw have shown that the reduction of constrained systems into its canonical, first-order form, can bring some new insight into the research of this field. For sympletic manifolds the geometrical structure, called Dirac or generalized bracket, is obtained directly from the inverse of the nonsingular sympletic two-form matrix. In the cases of nonsympletic manifolds, this two-form is degenerated and cannot be inverted to provide the generalized brackets. This singular behavior of the sympletic matrix is indicative of the presence of constraints that have to be carefully considered to yield to consistent results. One has two possible routes to treat this problem: Dirac has taught us how to implement the constraints into the potential part (Hamiltonian) of the canonical Lagrangian, leading to the well-known Dirac brackets, which are consistent with the constraints and can be mapped into quantum commutators (modulo ordering terms). The second route, suggested by Faddeev and Jackiw, and followed in this paper, is to implement the constraints directly into the canonical part of the first order Lagrangian, using the fact that the consistence condition for the stability of the constrained manifold is linear in the time derivative. This algorithm may lead to an invertible two-form sympletic matrix from where the Dirac brackets are readily obtained. This algorithm is used in this paper to investigate some aspects of the quantization of constrained systems with first- and second-class constraints in the sympletic approach

  12. Pair Production Constraints on Superluminal Neutrinos Revisited

    International Nuclear Information System (INIS)

    Brodsky, Stanley

    2012-01-01

    We revisit the pair creation constraint on superluminal neutrinos considered by Cohen and Glashow in order to clarify which types of superluminal models are constrained. We show that a model in which the superluminal neutrino is effectively light-like can evade the Cohen-Glashow constraint. In summary, any model for which the CG pair production process operates is excluded because such timelike neutrinos would not be detected by OPERA or other experiments. However, a superluminal neutrino which is effectively lightlike with fixed p 2 can evade the Cohen-Glashow constraint because of energy-momentum conservation. The coincidence involved in explaining the SN1987A constraint certainly makes such a picture improbable - but it is still intrinsically possible. The lightlike model is appealing in that it does not violate Lorentz symmetry in particle interactions, although one would expect Hughes-Drever tests to turn up a violation eventually. Other evasions of the CG constraints are also possible; perhaps, e.g., the neutrino takes a 'short cut' through extra dimensions or suffers anomalous acceleration in matter. Irrespective of the OPERA result, Lorentz-violating interactions remain possible, and ongoing experimental investigation of such possibilities should continue.

  13. Forces Associated with Nonlinear Nonholonomic Constraint Equations

    Science.gov (United States)

    Roithmayr, Carlos M.; Hodges, Dewey H.

    2010-01-01

    A concise method has been formulated for identifying a set of forces needed to constrain the behavior of a mechanical system, modeled as a set of particles and rigid bodies, when it is subject to motion constraints described by nonholonomic equations that are inherently nonlinear in velocity. An expression in vector form is obtained for each force; a direction is determined, together with the point of application. This result is a consequence of expressing constraint equations in terms of dot products of vectors rather than in the usual way, which is entirely in terms of scalars and matrices. The constraint forces in vector form are used together with two new analytical approaches for deriving equations governing motion of a system subject to such constraints. If constraint forces are of interest they can be brought into evidence in explicit dynamical equations by employing the well-known nonholonomic partial velocities associated with Kane's method; if they are not of interest, equations can be formed instead with the aid of vectors introduced here as nonholonomic partial accelerations. When the analyst requires only the latter, smaller set of equations, they can be formed directly; it is not necessary to expend the labor to form the former, larger set first and subsequently perform matrix multiplications.

  14. The use of dose constraints concept

    International Nuclear Information System (INIS)

    Dina, Dumitru; Andrei, Veronica; Glodeanu, Florin; Goicea, Andrei

    2003-01-01

    The 1990 Recommendations of the International Commission on Radiological Protection (ICRP Publication 60) explicitly introduced the concept of 'dose constraints' within the context of optimization of protection. The concept was not new and the meaning of its introduction was an attempt to consolidate and rationalize various concepts already existing in the ICRP guidance. In Romania the Order of National Commission for Control of Nuclear Activities - CNCAN no. 14/2000, for approval of the Fundamental Regulations for Radiological Safety, may impose the use of dose constraints for practices or for specific radiation sources inside the practices when required. Dose constraints would be used like upper bound in radioprotection optimization. The use of dose constraints is not an easy task because the understanding and interpretation of its meaning and application in the regulatory and operational practice is still under development. For operation of Cernavoda Nuclear Power Plant - Unit 1 as well as in the implementation of the new Interim Spent Fuel Dry Storage Facility project the dose constraints concept was used in the licensing process. On this basis the authorized dose limit and legal dose limit concepts became clearer and would be used within the documents. (authors)

  15. Diffusion Processes Satisfying a Conservation Law Constraint

    Directory of Open Access Journals (Sweden)

    J. Bakosi

    2014-01-01

    Full Text Available We investigate coupled stochastic differential equations governing N nonnegative continuous random variables that satisfy a conservation principle. In various fields a conservation law requires a set of fluctuating variables to be nonnegative and (if appropriately normalized sum to one. As a result, any stochastic differential equation model to be realizable must not produce events outside of the allowed sample space. We develop a set of constraints on the drift and diffusion terms of such stochastic models to ensure that both the nonnegativity and the unit-sum conservation law constraints are satisfied as the variables evolve in time. We investigate the consequences of the developed constraints on the Fokker-Planck equation, the associated system of stochastic differential equations, and the evolution equations of the first four moments of the probability density function. We show that random variables, satisfying a conservation law constraint, represented by stochastic diffusion processes, must have diffusion terms that are coupled and nonlinear. The set of constraints developed enables the development of statistical representations of fluctuating variables satisfying a conservation law. We exemplify the results with the bivariate beta process and the multivariate Wright-Fisher, Dirichlet, and Lochner’s generalized Dirichlet processes.

  16. Generalizing Backtrack-Free Search: A Framework for Search-Free Constraint Satisfaction

    Science.gov (United States)

    Jonsson, Ari K.; Frank, Jeremy

    2000-01-01

    Tractable classes of constraint satisfaction problems are of great importance in artificial intelligence. Identifying and taking advantage of such classes can significantly speed up constraint problem solving. In addition, tractable classes are utilized in applications where strict worst-case performance guarantees are required, such as constraint-based plan execution. In this work, we present a formal framework for search-free (backtrack-free) constraint satisfaction. The framework is based on general procedures, rather than specific propagation techniques, and thus generalizes existing techniques in this area. We also relate search-free problem solving to the notion of decision sets and use the result to provide a constructive criterion that is sufficient to guarantee search-free problem solving.

  17. Constraint-induced movement therapy promotes brain functional reorganization in stroke patients with hemiplegia.

    Science.gov (United States)

    Wang, Wenqing; Wang, Aihui; Yu, Limin; Han, Xuesong; Jiang, Guiyun; Weng, Changshui; Zhang, Hongwei; Zhou, Zhiqiang

    2012-11-15

    Stroke patients with hemiplegia exhibit flexor spasms in the upper limb and extensor spasms in the lower limb, and their movement patterns vary greatly. Constraint-induced movement therapy is an upper limb rehabilitation technique used in stroke patients with hemiplegia; however, studies of lower extremity rehabilitation are scarce. In this study, stroke patients with lower limb hemiplegia underwent conventional Bobath therapy for 4 weeks as baseline treatment, followed by constraint-induced movement therapy for an additional 4 weeks. The 10-m maximum walking speed and Berg balance scale scores significantly improved following treatment, and lower extremity motor function also improved. The results of functional MRI showed that constraint-induced movement therapy alleviates the reduction in cerebral functional activation in patients, which indicates activation of functional brain regions and a significant increase in cerebral blood perfusion. These results demonstrate that constraint-induced movement therapy promotes brain functional reorganization in stroke patients with lower limb hemiplegia.

  18. Constraint-induced movement therapy promotes brain functional reorganization in stroke patients with hemiplegia

    Science.gov (United States)

    Wang, Wenqing; Wang, Aihui; Yu, Limin; Han, Xuesong; Jiang, Guiyun; Weng, Changshui; Zhang, Hongwei; Zhou, Zhiqiang

    2012-01-01

    Stroke patients with hemiplegia exhibit flexor spasms in the upper limb and extensor spasms in the lower limb, and their movement patterns vary greatly. Constraint-induced movement therapy is an upper limb rehabilitation technique used in stroke patients with hemiplegia; however, studies of lower extremity rehabilitation are scarce. In this study, stroke patients with lower limb hemiplegia underwent conventional Bobath therapy for 4 weeks as baseline treatment, followed by constraint-induced movement therapy for an additional 4 weeks. The 10-m maximum walking speed and Berg balance scale scores significantly improved following treatment, and lower extremity motor function also improved. The results of functional MRI showed that constraint-induced movement therapy alleviates the reduction in cerebral functional activation in patients, which indicates activation of functional brain regions and a significant increase in cerebral blood perfusion. These results demonstrate that constraint-induced movement therapy promotes brain functional reorganization in stroke patients with lower limb hemiplegia. PMID:25337108

  19. On Convergence of Inexact Augmented Lagrangians for Separable and Equality Convex QCQP Problems without Constraint Qualification

    Directory of Open Access Journals (Sweden)

    Zdenek Dostal

    2017-01-01

    Full Text Available The classical convergence theory of the augmented Lagrangian method has been developed under the assumption that the solutions satisfy a constraint qualification. The point of this note is to show that the constraint qualification can be limited to the constraints that are not enforced by the Lagrange multipliers. In particular, it follows that if the feasible set is non-empty and the inequality constraints are convex and separable, then the convergence of the algorithm is guaranteed without any additional assumptions. If the feasible set is empty and the projected gradients of the Lagrangians are forced to go to zero, then the iterates are shown to converge to the nearest well posed problem.

  20. Photoactive devices including porphyrinoids with coordinating additives

    Science.gov (United States)

    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.

  1. Dimensional modeling: beyond data processing constraints.

    Science.gov (United States)

    Bunardzic, A

    1995-01-01

    in the relational databases normalized to their 3rd normal form. Object-oriented approach insists on the importance of the common sense component of the data processing activities. But, particularly interesting, is the approach that advocates the necessity of 'flattening' the structure of the business models as we know them today. This discipline is called Dimensional Modeling and it enables users to form multidimensional views of the relevant facts which are stored in a 'flat' (non-structured), easy-to-comprehend and easy-to-access database. When using dimensional modeling, we relax many of the axioms inherent in a relational model. We focus on the knowledge of the relevant facts which are reflecting the business operations and are the real basis for the decision support and business analysis. At the core of the dimensional modeling are fact tables that contain the non-discrete, additive data. To determine the level of aggregation of these facts, we use granularity tables that specify the resolution, or the level/detail, that the user is allowed to entertain. The third component is dimension tables that embody the knowledge of the constraints to be used to form the views.

  2. Internalizing and Externalizing in Adolescence: The Roles of Academic Self-Efficacy and Gender

    Science.gov (United States)

    Rocchino, Gabrielle H.; Dever, Bridget V.; Telesford, Alana; Fletcher, Kristen

    2017-01-01

    This study examines academic self-efficacy and gender as predictors of internalizing and externalizing behaviors in adolescence. In addition, the role of gender was considered as a moderator in the relationship between academic self-efficacy and internalizing/externalizing difficulties. Participants were 4,318 predominantly African American,…

  3. A Classroom Game on a Negative Externality Correcting Tax: Revenue Return, Regressivity, and the Double Dividend

    Science.gov (United States)

    Duke, Joshua M.; Sassoon, David M.

    2017-01-01

    The concept of negative externality is central to the teaching of environmental economics, but corrective taxes are almost always regressive. How exactly might governments return externality-correcting tax revenue to overcome regressivity and not alter marginal incentives? In addition, there is a desire to achieve a double dividend in the use of…

  4. Constraints and Creativity in NPD - Testing the Impact of 'Late Constraints'

    DEFF Research Database (Denmark)

    Onarheim, Balder; Valgeirsdóttir, Dagný

    The aim of the presented work is to investigate how the timing of project constraints can influence the creativity of the output in New Product Development (NPD) projects. When seeking to produce a creative output, is it beneficial to know all constraints when initiating a project......, or will constraints introduced throughout a project potentially lead to a more creative output? While the relationship between constraints and creativity is fairly well studied, the question of how introducing constraints late in a project can influence creativity is still unanswered. A single factor, two level...... was assessed for creativity using the Consensual Assessment Technique (CAT), and a comparative within-subjects analysis found no significant different between the two conditions. Controlling for task and assessor a small but non-significant effect was found, in favor of the ‘late constraint’ condition. Thus...

  5. Constraints and spandrels of interareal connectomes

    Science.gov (United States)

    Rubinov, Mikail

    2016-12-01

    Interareal connectomes are whole-brain wiring diagrams of white-matter pathways. Recent studies have identified modules, hubs, module hierarchies and rich clubs as structural hallmarks of these wiring diagrams. An influential current theory postulates that connectome modules are adequately explained by evolutionary pressures for wiring economy, but that the other hallmarks are not explained by such pressures and are therefore less trivial. Here, we use constraint network models to test these postulates in current gold-standard vertebrate and invertebrate interareal-connectome reconstructions. We show that empirical wiring-cost constraints inadequately explain connectome module organization, and that simultaneous module and hub constraints induce the structural byproducts of hierarchies and rich clubs. These byproducts, known as spandrels in evolutionary biology, include the structural substrate of the default-mode network. Our results imply that currently standard connectome characterizations are based on circular analyses or double dipping, and we emphasize an integrative approach to future connectome analyses for avoiding such pitfalls.

  6. Lorentz violation. Motivation and new constraints

    International Nuclear Information System (INIS)

    Liberati, S.; Maccione, L.

    2009-09-01

    We review the main theoretical motivations and observational constraints on Planck scale sup-pressed violations of Lorentz invariance. After introducing the problems related to the phenomenological study of quantum gravitational effects, we discuss the main theoretical frameworks within which possible departures from Lorentz invariance can be described. In particular, we focus on the framework of Effective Field Theory, describing several possible ways of including Lorentz violation therein and discussing their theoretical viability. We review the main low energy effects that are expected in this framework. We discuss the current observational constraints on such a framework, focusing on those achievable through high-energy astrophysics observations. In this context we present a summary of the most recent and strongest constraints on QED with Lorentz violating non-renormalizable operators. Finally, we discuss the present status of the field and its future perspectives. (orig.)

  7. Lorentz violation. Motivation and new constraints

    Energy Technology Data Exchange (ETDEWEB)

    Liberati, S. [Scuola Internazionale Superiore di Studi Avanzati SISSA, Trieste (Italy); Istituto Nazionale di Fisica Nucleare INFN, Sezione di Trieste (Italy); Maccione, L. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2009-09-15

    We review the main theoretical motivations and observational constraints on Planck scale sup-pressed violations of Lorentz invariance. After introducing the problems related to the phenomenological study of quantum gravitational effects, we discuss the main theoretical frameworks within which possible departures from Lorentz invariance can be described. In particular, we focus on the framework of Effective Field Theory, describing several possible ways of including Lorentz violation therein and discussing their theoretical viability. We review the main low energy effects that are expected in this framework. We discuss the current observational constraints on such a framework, focusing on those achievable through high-energy astrophysics observations. In this context we present a summary of the most recent and strongest constraints on QED with Lorentz violating non-renormalizable operators. Finally, we discuss the present status of the field and its future perspectives. (orig.)

  8. Latin hypercube sampling with inequality constraints

    International Nuclear Information System (INIS)

    Iooss, B.; Petelet, M.; Asserin, O.; Loredo, A.

    2010-01-01

    In some studies requiring predictive and CPU-time consuming numerical models, the sampling design of the model input variables has to be chosen with caution. For this purpose, Latin hypercube sampling has a long history and has shown its robustness capabilities. In this paper we propose and discuss a new algorithm to build a Latin hypercube sample (LHS) taking into account inequality constraints between the sampled variables. This technique, called constrained Latin hypercube sampling (cLHS), consists in doing permutations on an initial LHS to honor the desired monotonic constraints. The relevance of this approach is shown on a real example concerning the numerical welding simulation, where the inequality constraints are caused by the physical decreasing of some material properties in function of the temperature. (authors)

  9. Data Driven Constraints for the SVM

    DEFF Research Database (Denmark)

    Darkner, Sune; Clemmensen, Line Katrine Harder

    2012-01-01

    classifier solution, compared to the SVM i.e. reduces variance and improves classification rates. We present a quantitative measure of the information level contained in the pairing and test the method on simulated as well as a high-dimensional paired data set of ear-canal surfaces.......We propose a generalized data driven constraint for support vector machines exemplified by classification of paired observations in general and specifically on the human ear canal. This is particularly interesting in dynamic cases such as tissue movement or pathologies developing over time....... Assuming that two observations of the same subject in different states span a vector, we hypothesise that such structure of the data contains implicit information which can aid the classification, thus the name data driven constraints. We derive a constraint based on the data which allow for the use...

  10. Using LDPC Code Constraints to Aid Recovery of Symbol Timing

    Science.gov (United States)

    Jones, Christopher; Villasnor, John; Lee, Dong-U; Vales, Esteban

    2008-01-01

    A method of utilizing information available in the constraints imposed by a low-density parity-check (LDPC) code has been proposed as a means of aiding the recovery of symbol timing in the reception of a binary-phase-shift-keying (BPSK) signal representing such a code in the presence of noise, timing error, and/or Doppler shift between the transmitter and the receiver. This method and the receiver architecture in which it would be implemented belong to a class of timing-recovery methods and corresponding receiver architectures characterized as pilotless in that they do not require transmission and reception of pilot signals. Acquisition and tracking of a signal of the type described above have traditionally been performed upstream of, and independently of, decoding and have typically involved utilization of a phase-locked loop (PLL). However, the LDPC decoding process, which is iterative, provides information that can be fed back to the timing-recovery receiver circuits to improve performance significantly over that attainable in the absence of such feedback. Prior methods of coupling LDPC decoding with timing recovery had focused on the use of output code words produced as the iterations progress. In contrast, in the present method, one exploits the information available from the metrics computed for the constraint nodes of an LDPC code during the decoding process. In addition, the method involves the use of a waveform model that captures, better than do the waveform models of the prior methods, distortions introduced by receiver timing errors and transmitter/ receiver motions. An LDPC code is commonly represented by use of a bipartite graph containing two sets of nodes. In the graph corresponding to an (n,k) code, the n variable nodes correspond to the code word symbols and the n-k constraint nodes represent the constraints that the code places on the variable nodes in order for them to form a valid code word. The decoding procedure involves iterative computation

  11. Coverage-based constraints for IMRT optimization

    Science.gov (United States)

    Mescher, H.; Ulrich, S.; Bangert, M.

    2017-09-01

    Radiation therapy treatment planning requires an incorporation of uncertainties in order to guarantee an adequate irradiation of the tumor volumes. In current clinical practice, uncertainties are accounted for implicitly with an expansion of the target volume according to generic margin recipes. Alternatively, it is possible to account for uncertainties by explicit minimization of objectives that describe worst-case treatment scenarios, the expectation value of the treatment or the coverage probability of the target volumes during treatment planning. In this note we show that approaches relying on objectives to induce a specific coverage of the clinical target volumes are inevitably sensitive to variation of the relative weighting of the objectives. To address this issue, we introduce coverage-based constraints for intensity-modulated radiation therapy (IMRT) treatment planning. Our implementation follows the concept of coverage-optimized planning that considers explicit error scenarios to calculate and optimize patient-specific probabilities q(\\hat{d}, \\hat{v}) of covering a specific target volume fraction \\hat{v} with a certain dose \\hat{d} . Using a constraint-based reformulation of coverage-based objectives we eliminate the trade-off between coverage and competing objectives during treatment planning. In-depth convergence tests including 324 treatment plan optimizations demonstrate the reliability of coverage-based constraints for varying levels of probability, dose and volume. General clinical applicability of coverage-based constraints is demonstrated for two cases. A sensitivity analysis regarding penalty variations within this planing study based on IMRT treatment planning using (1) coverage-based constraints, (2) coverage-based objectives, (3) probabilistic optimization, (4) robust optimization and (5) conventional margins illustrates the potential benefit of coverage-based constraints that do not require tedious adjustment of target volume objectives.

  12. Constraints on hadronically decaying dark matter

    International Nuclear Information System (INIS)

    Garny, Mathias; Ibarra, Alejandro; Tran, David; Minnesota Univ., Minneapolis, MN

    2012-05-01

    We present general constraints on dark matter stability in hadronic decay channels derived from measurements of cosmic-ray antiprotons.We analyze various hadronic decay modes in a model-independent manner by examining the lowest-order decays allowed by gauge and Lorentz invariance for scalar and fermionic dark matter particles and present the corresponding lower bounds on the partial decay lifetimes in those channels. We also investigate the complementarity between hadronic and gamma-ray constraints derived from searches for monochromatic lines in the sky, which can be produced at the quantum level if the dark matter decays into quark-antiquark pairs at leading order.

  13. Constraint specialisation in Horn clause verification

    DEFF Research Database (Denmark)

    Kafle, Bishoksan; Gallagher, John Patrick

    2017-01-01

    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 transformed version of a given set of clauses and a goal. The constraints from the model are then used to compute...... underlying the clauses. Experimental results on verification problems show that this is an effective transformation, both in our own verification tools (based on a convex polyhedra analyser) and as a pre-processor to other Horn clause verification tools....

  14. On the evolutionary constraint surface of hydra

    Science.gov (United States)

    Slobodkin, L. B.; Dunn, K.

    1983-01-01

    Food consumption, body size, and budding rate were measured simultaneously in isolated individual hydra of six strains. For each individual hydra the three measurements define a point in the three dimensional space with axes: food consumption, budding rate, and body size. These points lie on a single surface, regardless of species. Floating rate and incidence of sexuality map onto this surface. It is suggested that this surface is an example of a general class of evolutionary constraint surfaces derived from the conjunction of evolutinary theory and the theory of ecological resource budgets. These constraint surfaces correspond to microevolutionary domains.

  15. Universal constraints on axions from inflation

    DEFF Research Database (Denmark)

    Ferreira, R. Z.; Sloth, M. S.

    2014-01-01

    through this mechanism, larger than the vacuum ones, without violating the observational constraints unless we combine this mechanism with a curvaton or if the sigma field becomes heavy and decays during inflation. Even in this last case there are non-trivial constraints coming from the slow......-roll evolution of the curvature perturbation on super horizon scales which should be taken into account. We also comment on implications for inflationary models where axions play an important role as, for example, models of natural inflation where more than one axion are included and models where the curvaton...

  16. Space Shuttle capabilities, constraints, and cost

    Science.gov (United States)

    Lee, C. M.

    1980-01-01

    The capabilities, constraints, and costs of the Space Transportation System (STS), which combines reusable and expendable components, are reviewed, and an overview of the current planning activities for operating the STS in an efficient and cost-effective manner is presented. Traffic forecasts, performance constraints and enhancements, and potential new applications are discussed. Attention is given to operating costs, pricing policies, and the steps involved in 'getting on board', which includes all the interfaces between NASA and the users necessary to come to launch service agreements.

  17. Financial Constraints and Nominal Price Rigidities

    DEFF Research Database (Denmark)

    Menno, Dominik Francesco; Balleer, Almut; Hristov, Nikolay

    that these empirical patterns are consistent with a partial equilibrium menu-cost model with a working capital constraint. We then use the model to show how the presence of financial frictions changes profits and the price distribution of firms compared to a model without financial frictions. Our results suggest...... that tighter financial constraints are associated with higher nominal rigidities, higher prices and lower output. Moreover, in response to aggregate shocks, aggregate price rigidity moves substantially, the response of inflation is dampened, while output reacts more in the presence of financial frictions...

  18. EXTERNAL ELEMENTS OF INTERCULTURAL MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Ruxandra GEORGESCU

    2017-12-01

    Full Text Available Because nowadays we attach a great importance to our look, this article wants to highlight certain aspects of intercultural management that are external to us, the personal label with which we "come into contact with the whole world” and also this article gives some suggestions that I want to consider for business success. As speakers of a language, we are both "producers" and "consumers" of it. In a sense, this is also the case for the dress code, the "language" of clothing: we dress in a certain way and this send messages to others; We perceive how others are dressed and so we receive messages from them. But there is no difference: we are not the ones who produce the signs. Beyond fashion, myths and motes, clothing, accessories, gesture, face expression, posture and body lines are the first elements that give visual identity to any person. In the business environment, as in the world of fashion, immediate visual identity is the one that generates the first impression.

  19. External plans for radiological emergency

    International Nuclear Information System (INIS)

    Suarez, G.; Vizuet G, J.; Benitez S, J.A.

    1999-01-01

    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)

  20. External quality assessment: best practice.

    Science.gov (United States)

    James, David; Ames, Darren; Lopez, Berenice; Still, Rachel; Simpson, Wiliam; Twomey, Patrick

    2014-08-01

    There is a requirement for accredited laboratories to participate in external quality assessment (EQA) schemes, but there is wide variation in understanding as to what is required by the laboratories and scheme providers in fulfilling this. This is not helped by a diversity of language used in connection with EQA; Proficiency testing (PT), EQA schemes, and EQA programmes, each of which have different meanings and offerings in the context of improving laboratory quality. We examine these differences, and identify what factors are important in supporting quality within a clinical laboratory and what should influence the choice of EQA programme. Equally as important is how EQA samples are handled within the laboratory, and how the information provided by the EQA programme is used. EQA programmes are a key element of a laboratory's quality assurance framework, but laboratories should have an understanding of what their EQA programmes are capable of demonstrating, how they should be used within the laboratory, and how they support quality. EQA providers should be clear as to what type of programme they provide - PT, EQA Scheme or EQA Programme. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  1. Clinical governance and external audit.

    Science.gov (United States)

    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.

  2. Human Sound Externalization in Reverberant Environments

    DEFF Research Database (Denmark)

    Catic, Jasmina

    In everyday environments, listeners perceive sound sources as externalized. In listening conditions where the spatial cues that are relevant for externalization are not represented correctly, such as when listening through headphones or hearing aids, a degraded perception of externalization may...... occur. In this thesis, the spatial cues that arise from a combined effect of filtering due to the head, torso, and pinna and the acoustic environment were analysed and the impact of such cues for the perception of externalization in different frequency regions was investigated. Distant sound sources...... were simulated via headphones using individualized binaural room impulse responses (BRIRs). An investigation of the influence of spectral content of a sound source on externalization showed that effective externalization cues are present across the entire frequency range. The fluctuation of interaural...

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

    DEFF Research Database (Denmark)

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

    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...

  4. Testing the Limits: The Purposes and Effects of Additional, External Elementary Mathematics Assessment

    Science.gov (United States)

    Lombardi, Karen Ann

    2011-01-01

    This mixed-methods case study focuses on the third through fifth grade classrooms at a public elementary school in a Midwestern urban school district where the Northwest Evaluation Association's (NWEA) Measures of Academic Progress (MAP) assessment is being implemented. According to the school district, the goals of these tests are: to show…

  5. Additive and polynomial representations

    CERN Document Server

    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

  6. Energy security externalities and fuel cycle comparisons

    International Nuclear Information System (INIS)

    Bohi, D.; Toman, M.

    1994-01-01

    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

  7. Risk analysis of external radiation therapy

    International Nuclear Information System (INIS)

    Arvidsson, Marcus

    2011-09-01

    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

  8. Early discharge after external anal sphincter repair

    DEFF Research Database (Denmark)

    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....... CONCLUSION: We have described a safe accelerated-stay program (24 to 48 hours) for overlapping repair of external anal sphincter....

  9. Food additives data book

    National Research Council Canada - National Science Library

    Smith, Jim; Hong-Shum, Lily

    2011-01-01

    .... Compiled by food industry experts with a proven track record of producing high quality reference work, this volume is the definitive resource for technologists using food additives"-- "The use...

  10. Food Additives and Hyperkinesis

    Science.gov (United States)

    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)

  11. Possible pathways between depression, emotional and external eating. A structural equation model.

    Science.gov (United States)

    Ouwens, Machteld A; van Strien, Tatjana; van Leeuwe, Jan F J

    2009-10-01

    Emotional and external eating appear to co-occur and both have been shown to correlate to neuroticism, especially depression. However, there is evidence suggesting that emotional and external eating are independent constructs. In this study we revisited the relation between depression, emotional, and external eating. Using structural equation modelling, we examined whether depression, emotional and external eating are directly related and also indirectly related through the intervening concepts alexithymia and impulsivity. Participants were 549 females concerned about their weight. They filled out instruments on emotional and external eating, depression, alexithymia, and impulse regulation. The relational structure between the model variables was explored for one half of the participants and this solution was checked using the other half. Our data showed a moderate relationship between emotional and external eating. Depression was positively and directly associated with emotional eating, but not with external eating. In addition, depression was indirectly related to emotional eating through both alexithymia and impulsivity. A significant relation was found between impulsivity and external eating. Results suggest potential mediating pathways between depression and emotional eating, while no relation appeared to exist between depression and external eating. Emotional and external eating would appear to be different constructs.

  12. Internal and External Readings of Same

    DEFF Research Database (Denmark)

    Hardt, Daniel

    2016-01-01

    is infelicitous in the absence of parallelism. Hardt and Mikkelsen propose an account that applies uniformly to internal and external readings; however, the evidence they present largely targets external readings – they don’t offer empirical evidence that clearly supports the uniform approach. Furthermore, Barker...... (2007) argues that internal readings must be treated differently than external readings. In this paper, I show that the parallelism effects observed by Hardt and Mikkelsen in fact apply to internal readings as well. This provides support for a uniform treatment of internal and external readings of same...

  13. Proceedings: National conference on environmental externalities

    International Nuclear Information System (INIS)

    1990-01-01

    This report is the proceedings of the National Conference on Environmental Externalities. A environmental externality is the environmental impact of a process or a plant that society must endure. It is a social cost and is paid, but not by the company who produced it or the company's customers who endure it. The main purpose of this report is to gather the many designs and ideas of how and why to internalize the externalities into the pricing systems of the public utility commissions, especially that of the electric utilities. Economic and sociological aspects of the internalization of these externalities are given in these proceedings. Individual papers are processed separately for databases. (MB)

  14. Tomato farmers adoption level of postharvest value addition ...

    African Journals Online (AJOL)

    The study examined tomato farmers' adoption level of postharvest value addition technology and its constraints in Surulere Area of Oyo state. 160 tomato farmers were randomly selected and interviewed through structured interview schedule. Data obtained were subjected to descriptive and inferential statistics. Results ...

  15. Constraints to Strategy Implementation and their Influence on Business Performance: the Case of a Waste Management Logistics Company

    Directory of Open Access Journals (Sweden)

    Chengedzai Mafini

    2016-08-01

    Full Text Available Waste management companies in developing countries often have to contend with a plethora of factors that inhibit their business performance. The primary objective of this study was to investigate the influence of constraints to strategy implementation on the business performance of a waste management logistics company in South Africa. The study was triggered by the lack of previous research focusing on constraints to strategy implementation in the waste management sector. The study employed a quantitative approach using the cross sectional survey design in which data were collected from 309 employees of a waste management logistics company based in Gauteng Province. Seven constraints to strategy implementation; namely, management practices, human resource capabilities, customer service, external orientation, internal communication, innovation and employee motivation were identified through Exploratory Factor Analysis. Pearson correlations showed that business performance is negatively affected as and when each constraint becomes more prevalent. Regression analysis showed that all constraints were statistically significant. To academics, the study provides current insights on factors impacting on business performance in waste management organisations. Management practitioners may improve the levels of business performance through structural adjustments of the seven constraints identified in this study. The study may be used as a reference point in the diagnosis of business performance related challenges in companies operating within the waste management sector.

  16. Comparison study of design rainfall mapping using ordinary kriging and kriging with external drift

    CSIR Research Space (South Africa)

    Khuluse, S

    2011-03-01

    Full Text Available rainfall surface in a case where the number of sampled sites is small using inverse distance weighting, ordinary kriging and kriging with external drift methods. Does incorporating additional explanatory information, given a spatially sparse sample, lead...

  17. Key External Influences Affecting Consumers’ Decisions Regarding Food

    Science.gov (United States)

    Martínez-Ruiz, María Pilar; Gómez-Cantó, Carmen María

    2016-01-01

    Among the numerous internal and external forces that compete for consumers’ attention in the context in which they buy their food, this paper will seek to provide a review of the most important external influences, such as the variables related to food itself. To this end, in addition to the food attributes traditionally identified in fields such as consumer behavior, it will give special consideration to the classification of food values. Although the influence of these variables on consumer decisions depends on the individual, analyzing them will undoubtedly increase understanding of consumers’ decisions. Additionally, identifying and describing these variables will enable subsequent research on how they influence both consumer behavior and other key outcomes for producers, manufacturers, and retailers in the food industry, such as satisfaction, trust, and loyalty. PMID:27803686

  18. Groundwater for sustainable development opportunities and constraints

    International Nuclear Information System (INIS)

    Abdel Rahman Attia, F.

    1999-01-01

    This paper discusses water resources availability and demand; concept and constraints of sustainable development; ground water protection. Water issues specific for arid zones and the network on ground water protection in the Arab region are discussed. Recommendations on ground water protection in arid zones are given

  19. Robust Utility Maximization Under Convex Portfolio Constraints

    International Nuclear Information System (INIS)

    Matoussi, Anis; Mezghani, Hanen; Mnif, Mohamed

    2015-01-01

    We study a robust maximization problem from terminal wealth and consumption under a convex constraints on the portfolio. We state the existence and the uniqueness of the consumption–investment strategy by studying the associated quadratic backward stochastic differential equation. We characterize the optimal control by using the duality method and deriving a dynamic maximum principle

  20. Choice within Constraints: Mothers and Schooling.

    Science.gov (United States)

    David, Miriam; Davies, Jackie; Edwards, Rosalind; Reay, Diane; Standing, Kay

    1997-01-01

    Explores, from a feminist perspective, the discourses of choice regarding how women make their choices as consumers in the education marketplace. It argues that mothers as parents are not free to choose but act within a range of constraints, i.e., their choices are limited by structural and moral possibilities in a patriarchal and racist society.…

  1. Robust Utility Maximization Under Convex Portfolio Constraints

    Energy Technology Data Exchange (ETDEWEB)

    Matoussi, Anis, E-mail: anis.matoussi@univ-lemans.fr [Université du Maine, Risk and Insurance institut of Le Mans Laboratoire Manceau de Mathématiques (France); Mezghani, Hanen, E-mail: hanen.mezghani@lamsin.rnu.tn; Mnif, Mohamed, E-mail: mohamed.mnif@enit.rnu.tn [University of Tunis El Manar, Laboratoire de Modélisation Mathématique et Numérique dans les Sciences de l’Ingénieur, ENIT (Tunisia)

    2015-04-15

    We study a robust maximization problem from terminal wealth and consumption under a convex constraints on the portfolio. We state the existence and the uniqueness of the consumption–investment strategy by studying the associated quadratic backward stochastic differential equation. We characterize the optimal control by using the duality method and deriving a dynamic maximum principle.

  2. Management practices and production constraints of central ...

    African Journals Online (AJOL)

    management practices of central highland goats and their major constraints. ... a basic education. Almost all 249 (99.6%) of the respondents practiced a mixed crop livestock production system, and majority of them (85.2%) reared goats ..... owners and the children who often keep the goats do not have adequate aware-.

  3. Prospects and Constraints of Household Irrigation Practices ...

    African Journals Online (AJOL)

    Constraints and prospects of hand dug wells related to household irrigation were assessed in Hayelom watershed (~1045 ha), by evaluating groundwater suitability for irrigation, soil quality and impact of intervention. 181 hand dug wells have come into existence in the watershed due to intervention and benefiting about ...

  4. Confluence Modulo Equivalence in Constraint Handling Rules

    DEFF Research Database (Denmark)

    Christiansen, Henning; Kirkeby, Maja Hanne

    2015-01-01

    Previous results on confluence for Constraint Handling Rules, CHR, are generalized to take into account user-defined state equivalence relations. This allows a much larger class of programs to enjoy the advantages of confluence, which include various optimization techniques and simplified...

  5. Inhomogeneous Diophantine approximation with prime constraints

    Indian Academy of Sciences (India)

    50

    constraints. In the present paper, we study an inhomogeneous version of the problem. Inhomogeneous Diophantine .... Our strategy is to split the interval [1,N] into subintervals [P, P µ] and sum up over the. P's in the end. Accordingly, we restrict p to the interval P ≤ p < Pµ with Pµ ≤ N. We then obtain a lower bound for (6) by ...

  6. Relationships Between Firm Characteristics and Export Constraints ...

    African Journals Online (AJOL)

    Relationships Between Firm Characteristics and Export Constraints in SME Exporters. Zororo Muranda. Abstract. No Abstract Available Zambezia (2003), XXX (i): 89-107. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/zjh.v30i1.6737.

  7. Integer Constraints for Train Series Connections

    NARCIS (Netherlands)

    R.A. Zuidwijk (Rob); L.G. Kroon (Leo)

    2000-01-01

    textabstractThe scheduling of train services is subject to a number of constraints describing railway infrastructure, required train services and reasonable time-intervals for waiting and transits. Timetable planners at Dutch Railways are nowadays supported by a software tool, called CADANS, which

  8. On the canonical treatment of Lagrangian constraints

    International Nuclear Information System (INIS)

    Barbashov, B.M.

    2001-01-01

    The canonical treatment of dynamic systems with manifest Lagrangian constraints proposed by Berezin is applied to concrete examples: a special Lagrangian linear in velocities, relativistic particles in proper time gauge, a relativistic string in orthonormal gauge, and the Maxwell field in the Lorentz gauge

  9. On the canonical treatment of Lagrangian constraints

    International Nuclear Information System (INIS)

    Barbashov, B.M.

    2001-01-01

    The canonical treatment of dynamic systems with manifest Lagrangian constraints proposed by Berezin is applied to concrete examples: a specific Lagrangian linear in velocities, relativistic particles in proper time gauge, a relativistic string in orthonormal gauge, and the Maxwell field in the Lorentz gauge

  10. Cognitive Dissonance Reduction as Constraint Satisfaction.

    Science.gov (United States)

    Shultz, Thomas R.; Lepper, Mark R.

    1996-01-01

    It is argued that the reduction of cognitive dissonance can be viewed as a constraint satisfaction problem, and a computational model of the process of consonance seeking is proposed. Simulations from this model matched psychological findings from the insufficient justification and free-choice paradigms of cognitive dissonance theory. (SLD)

  11. Further Note on the Probabilistic Constraint Handling

    NARCIS (Netherlands)

    Ciftcioglu, O.; Bittermann, M.S.; Datta, R

    2016-01-01

    A robust probabilistic constraint handling approach in the framework of joint evolutionary-classical optimization has been presented earlier. In this work, the
    theoretical foundations of the method are presented in detail. The method is known as bi-objective method, where the conventional

  12. CONSTRAINTS TO USE OF MOBILE TELEPHONY FOR ...

    African Journals Online (AJOL)

    services by mobile telecommunications service providers, regular electric power supply, training of the farmers by extension agents and agricultural development agencies as well as formation of agricultural societies by the farmers. Key words: Constraints, mobile telephony, frequency, farmers and telecommunications ...

  13. Organizing Creativity : Creativity and Innovation under Constraints

    NARCIS (Netherlands)

    Caniëls, Marjolein C.J.; Rietzschel, Eric F.

    2015-01-01

    The best way of organizing creativity within organizations remains somewhat enigmatic to scholars, particularly when it comes to the role of constraints. On the one hand, creative organizations are often associated with freedom, autonomy, weak rules and few boundaries. On the other hand, several

  14. Calmness of constraint systems with applications

    Czech Academy of Sciences Publication Activity Database

    Outrata, Jiří; Henrion, R.

    2005-01-01

    Roč. 104, 2/3 (2005), s. 437-464 ISSN 0025-5610 R&D Projects: GA AV ČR IAA1030405 Grant - others:DFG(DE) Matheon Institutional research plan: CEZ:AV0Z10750506 Keywords : calmness * constraint sets * nonsmooth calculus Subject RIV: BA - General Mathematics Impact factor: 1.497, year: 2005

  15. Value constraints in the CLP scheme

    NARCIS (Netherlands)

    M.H. van Emden

    1996-01-01

    textabstractThis paper addresses the question of how to incorporate constraint propagation into logic programming. A likely candidate is the CLP scheme, which allows one to exploit algorithmic opportunities while staying within logic programming semantics. CLP($cal R$) is an example: it combines

  16. Fish farmers' perceptions of constraints affecting aquaculture ...

    African Journals Online (AJOL)

    The study focused on fish farmers' perceptions of constraints affecting aquaculture development in Akwa-Ibom State of Nigeria. Random sampling procedure was used to select 120 respondents from whom primary data was collected. Data analysis was with the aid of descriptive statistics. Results show that fish farming ...

  17. Institutional and resource constraints that inhibit contractor ...

    African Journals Online (AJOL)

    Results show that contractors face institutional constraints (work allocation limitations, lack of performance incentives and high transaction costs, such as negotiation costs, the risk of a loss in work and contract default risk), cash flow problems, poor physical infrastructure and a lack of labour. It is expected that the promotion ...

  18. Loosening Psychometric Constraints on Educational Assessments

    Science.gov (United States)

    Kane, Michael T.

    2017-01-01

    In response to an argument by Baird, Andrich, Hopfenbeck and Stobart (2017), Michael Kane states that there needs to be a better fit between educational assessment and learning theory. In line with this goal, Kane will examine how psychometric constraints might be loosened by relaxing some psychometric "rules" in some assessment…

  19. Constraints on the CP-Violating MSSM

    CERN Document Server

    Arbey, A; Godbole, R M; Mahmoudi, F

    2016-01-01

    We discuss the prospects for observing CP violation in the MSSM with six CP-violating phases, using a geometric approach to maximise CP-violating observables subject to the experimental upper bounds on electric dipole moments. We consider constraints from Higgs physics, flavour physics, the dark matter relic density and spin-independent scattering cross section with matter.

  20. Constraints to Gender Participation in Rural Community ...

    African Journals Online (AJOL)

    User

    Dept. of Agricultural Extension, Faculty of Agriculture,. University of Nigeria, Nsukka. E-mail: juliewuchukwu@yahoo.com. Phone: 08063276459. Abstract. This study examined constraints to gender participation in rural community development in Abia State. A multistage sampling procedure was used in the selection of 120 ...

  1. Constraints To Effective Community Development Projects Among ...

    African Journals Online (AJOL)

    The study focused on the perceived constraints to effective community development projects among rural households in Calabar agricultural zone of Cross River State, Nigeria. Data were collected with the aid of structured questionnaire from 104 randomly selected respondents in the study area. Data analysis was by the ...

  2. Tilapia culture in Kuwait: constraints and solutions

    OpenAIRE

    Ridha, M.T.

    2006-01-01

    Tilapia farming in Kuwait is in its early stages. Slow growth, high production cost and poor demand are the major constraints to the expansion of tilapia culture in Kuwait. This article presents some suggestions for overcoming these problems to improve the economic feasibility of tilapia culture in Kuwait.

  3. Quantum centipedes with strong global constraint

    Science.gov (United States)

    Grange, Pascal

    2017-06-01

    A centipede made of N quantum walkers on a one-dimensional lattice is considered. The distance between two consecutive legs is either one or two lattice spacings, and a global constraint is imposed: the maximal distance between the first and last leg is N  +  1. This is the strongest global constraint compatible with walking. For an initial value of the wave function corresponding to a localized configuration at the origin, the probability law of the first leg of the centipede can be expressed in closed form in terms of Bessel functions. The dispersion relation and the group velocities are worked out exactly. Their maximal group velocity goes to zero when N goes to infinity, which is in contrast with the behaviour of group velocities of quantum centipedes without global constraint, which were recently shown by Krapivsky, Luck and Mallick to give rise to ballistic spreading of extremal wave-front at non-zero velocity in the large-N limit. The corresponding Hamiltonians are implemented numerically, based on a block structure of the space of configurations corresponding to compositions of the integer N. The growth of the maximal group velocity when the strong constraint is gradually relaxed is explored, and observed to be linear in the density of gaps allowed in the configurations. Heuristic arguments are presented to infer that the large-N limit of the globally constrained model can yield finite group velocities provided the allowed number of gaps is a finite fraction of N.

  4. Observational constraints on extended Chaplygin gas cosmologies

    Indian Academy of Sciences (India)

    B C Paul

    2017-07-24

    Jul 24, 2017 ... The speed of sound obtained in the model is small, necessary for structure formation. We also determine the observational constraints on the constants of the ECG equation. Keywords. Modified Chaplygin gas; accelerating Universe; dark energy. PACS Nos 04.20.–q; 98.80.Jk; 98.80.–k. 1. Introduction.

  5. A Microkernel Architecture for Constraint Programming

    OpenAIRE

    Michel, Laurent; Van Hentenryck, Pascal

    2014-01-01

    This paper presents a microkernel architecture for constraint programming organized around a number of small number of core functionalities and minimal interfaces. The architecture contrasts with the monolithic nature of many implementations. Experimental results indicate that the software engineering benefits are not incompatible with runtime efficiency.

  6. Ability or Finances as Constraints to Entrepreneurship?

    DEFF Research Database (Denmark)

    Andersen, Steffen; Meisner Nielsen, Kasper

    This study exploits a natural experiment to investigate why financial constraints appear to limit firm formation. Exogenous variation in wealth results from unexpected inheritance due to sudden death and allows us to identify 304 constrained entrepreneurs, who start a business after receiving win...

  7. CONSTRAINTS AND PROBLEMS OF INTERNET SERVICES IN ...

    African Journals Online (AJOL)

    ... Obafemi Awolowo University, Ile-Ife who were presently at the thesis writing stage of their programmes. The results from the analysis of the responses showed that the greatest constraints to Internet connectivity and usage was the high cost involved, while the associated problems were identified as incessant power failure ...

  8. Constraint-induced movement therapy after stroke

    NARCIS (Netherlands)

    Kwakkel, G.; Veerbeek, J.M.; van Wegen, E.E.H.; Wolf, S.L.

    2015-01-01

    Constraint-induced movement therapy (CIMT) was developed to overcome upper limb impairments after stroke and is the most investigated intervention for the rehabilitation of patients. Original CIMT includes constraining of the non-paretic arm and task-oriented training. Modified versions also apply

  9. Coping with Algebraic Constraints in Power Networks

    NARCIS (Netherlands)

    Monshizadeh, Nima; De Persis, Claudio; van der Schaft, Abraham; Scherpen, Jacquelien M.A.

    2016-01-01

    In the intuitive modelling of the power network, the generators and the loads are located at different subset of nodes. This corresponds to the so-called structure preserving model which is naturally expressed in terms of differential algebraic equations (DAE). The algebraic constraints in the

  10. Coverage maximization under resource constraints using ...

    Indian Academy of Sciences (India)

    2015-02-07

    Feb 7, 2015 ... Dissemination of information has been one of the prime needs in almost every kind of communication network. The existing algorithms for this service, try to maximize the coverage, i.e., the number of distinct nodes to which a given piece of information could be conveyed under the constraints of time and ...

  11. Ability or Finances as Constraints on Entrepreneurship?

    DEFF Research Database (Denmark)

    Andersen, Steffen; Meisner Nielsen, Kasper

    We use a natural experiment in Denmark to test the hypothesis that aspiring entrepreneurs face financial constraints because of low entrepreneurial quality. We identify 304 constrained entrepreneurs who start a business after receiving windfall wealth and examine the performance of these marginal...

  12. Ability or Finances as Constraints on Entrepreneurship?

    DEFF Research Database (Denmark)

    Andersen, Steffen; Meisner Nielsen, Kasper

    2012-01-01

    We use a natural experiment in Denmark to test the hypothesis that aspiring entrepreneurs face financial constraints because of low entrepreneurial quality. We identify 304 constrained entrepreneurs who start a business after receiving windfall wealth and examine the performance of these marginal...

  13. Energetic constraints on species coexistence in birds

    NARCIS (Netherlands)

    Pigot, Alexander L.; Tobias, Joseph A.; Jetz, Walter

    2016-01-01

    The association between species richness and ecosystem energy availability is one of the major geographic trends in biodiversity. It is often explained in terms of energetic constraints, such that coexistence among competing species is limited in low productivity environments. However, it has proven

  14. Constraints to Women Farmers' Entrepreneurial Development in ...

    African Journals Online (AJOL)

    User

    Abstract. This study examined the entrepreneurial competencies among women farmers in Nasarawa State, Nigeria. Specifically, this paper described the characteristics of the respondents, identified the characteristics (type, form and duration) of enterprises the respondents engaged in, and examined their constraints to ...

  15. Preconditioning for partial differential equation constrained optimization with control constraints

    KAUST Repository

    Stoll, Martin

    2011-10-18

    Optimal control problems with partial differential equations play an important role in many applications. The inclusion of bound constraints for the control poses a significant additional challenge for optimization methods. In this paper, we propose preconditioners for the saddle point problems that arise when a primal-dual active set method is used. We also show for this method that the same saddle point system can be derived when the method is considered as a semismooth Newton method. In addition, the projected gradient method can be employed to solve optimization problems with simple bounds, and we discuss the efficient solution of the linear systems in question. In the case when an acceleration technique is employed for the projected gradient method, this again yields a semismooth Newton method that is equivalent to the primal-dual active set method. We also consider the Moreau-Yosida regularization method for control constraints and efficient preconditioners for this technique. Numerical results illustrate the competitiveness of these approaches. © 2011 John Wiley & Sons, Ltd.

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

    DEFF Research Database (Denmark)

    Nielsen, Per Sieverts; Ibsen, Liselotte Schleisner

    1998-01-01

    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...... show that estimated damages due to the greenhouse effect are predominant, however, the uncertainty is high. The predominant damage at the local and regional level is related to emission of NOx, which results in effects on public health....... the use of a software package, EcoSence, having an environmental database at both a local and regional level including population, crops, building materials and forest. The system also incorporates two air transport models, allowing local and regional scale modelling. The results of the Danish case study...

  17. Adaptive Boundary Iterative Learning Control for an Euler-Bernoulli Beam System With Input Constraint.

    Science.gov (United States)

    He, Wei; Meng, Tingting; Huang, Deqing; Li, Xuefang

    2017-03-15

    This paper addresses the vibration control and the input constraint for an Euler-Bernoulli beam system under aperiodic distributed disturbance and aperiodic boundary disturbance. Hyperbolic tangent functions and saturation functions are adopted to tackle the input constraint. A restrained adaptive boundary iterative learning control (ABILC) law is proposed based on a time-weighted Lyapunov-Krasovskii-like composite energy function. In order to deal with the uncertainty of a system parameter and reject the external disturbances, three adaptive laws are designed and learned in the iteration domain. All the system states of the closed-loop system are proved to be bounded in each iteration. Along the iteration axis, the displacements asymptotically converge toward zero. Simulation results are provided to illustrate the effectiveness of the proposed ABILC scheme.

  18. ADVANTAGES AND CONSTRAINTS OF INNOVATIVE BUSINESS MODELS FOR FOOD SECURITY: CASE STUDY IN SMOLYAN DISTRICT, BULGARIA

    Directory of Open Access Journals (Sweden)

    Dimitre NIKOLOV

    2018-02-01

    Full Text Available The market access has been often defined as a factor having the strongest impact on agriculturalsector activity. Its importance is particularly critical for the small farms, which could not offer theirproduction on the market through single and sporadic sales. They could overcome these weaknessesof their business through participation in cooperative marketing. This article goal is to establish theadvantages and the constraints of cooperative business marketing model for food security in farmsof Smolyan district, Bulgaria. Farmers expect some advantages from the participation in such cooperationform. Three are the main approved advantages: 1 better awareness of market requirements; 2 marketaccess facilitation; 3 realization of higher profit from the activity. These advantages are expectedas a result form the direct contact with the final consumers, without external mediators. The implementationof cooperative marketing has its challenges embarrassing its effective use. The main constraints are relatedto the efficiency of processes management and to the coordination of activities of different economic entities.

  19. Ordinary people think free will is a lack of constraint, not the presence of a soul.

    Science.gov (United States)

    Vonasch, Andrew J; Baumeister, Roy F; Mele, Alfred R

    2018-03-16

    Four experiments supported the hypothesis that ordinary people understand free will as meaning unconstrained choice, not having a soul. People consistently rated free will as being high unless reduced by internal constraints (i.e., things that impaired people's mental abilities to make choices) or external constraints (i.e., situations that hampered people's abilities to choose and act as they desired). Scientific paradigms that have been argued to disprove free will were seen as reducing, but usually not eliminating free will, and the reductions were because of constrained conscious choice. We replicated findings that a minority of people think lacking a soul reduces free will. These reductions in perceived free will were fully explained by reductions in people's perceived abilities to make conscious decisions. Thus, some people do think you need a soul to have free will-but it is because they think you need a soul to make conscious decisions. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. Spacecraft reorientation control in presence of attitude constraint considering input saturation and stochastic disturbance

    Science.gov (United States)

    Cheng, Yu; Ye, Dong; Sun, Zhaowei; Zhang, Shijie

    2018-03-01

    This paper proposes a novel feedback control law for spacecraft to deal with attitude constraint, input saturation, and stochastic disturbance during the attitude reorientation maneuver process. Applying the parameter selection method to improving the existence conditions for the repulsive potential function, the universality of the potential-function-based algorithm is enhanced. Moreover, utilizing the auxiliary system driven by the difference between saturated torque and command torque, a backstepping control law, which satisfies the input saturation constraint and guarantees the spacecraft stability, is presented. Unlike some methods that passively rely on the inherent characteristic of the existing controller to stabilize the adverse effects of external stochastic disturbance, this paper puts forward a nonlinear disturbance observer to compensate the disturbance in real-time, which achieves a better performance of robustness. The simulation results validate the effectiveness, reliability, and universality of the proposed control law.

  1. Self-injury and externalizing pathology: a systematic literature review

    OpenAIRE

    Meszaros, Gergely; Horvath, Lili Olga; Balazs, Judit

    2017-01-01

    Background During the last decade there is a growing scientific interest in nonsuicidal self-injury (NSSI). The aim of the current paper was to review systematically the literature with a special focus on the associations between self-injurious behaviours and externalizing psychopathology. An additional aim was to review terminology and measurements of self-injurious behaviour and the connection between self-injurious behaviours and suicide in the included publications. Methods A systematic l...

  2. A Hybrid Method for Modeling and Solving Supply Chain Optimization Problems with Soft and Logical Constraints

    Directory of Open Access Journals (Sweden)

    Paweł Sitek

    2016-01-01

    Full Text Available This paper presents a hybrid method for modeling and solving supply chain optimization problems with soft, hard, and logical constraints. Ability to implement soft and logical constraints is a very important functionality for supply chain optimization models. Such constraints are particularly useful for modeling problems resulting from commercial agreements, contracts, competition, technology, safety, and environmental conditions. Two programming and solving environments, mathematical programming (MP and constraint logic programming (CLP, were combined in the hybrid method. This integration, hybridization, and the adequate multidimensional transformation of the problem (as a presolving method helped to substantially reduce the search space of combinatorial models for supply chain optimization problems. The operation research MP and declarative CLP, where constraints are modeled in different ways and different solving procedures are implemented, were linked together to use the strengths of both. This approach is particularly important for the decision and combinatorial optimization models with the objective function and constraints, there are many decision variables, and these are summed (common in manufacturing, supply chain management, project management, and logistic problems. The ECLiPSe system with Eplex library was proposed to implement a hybrid method. Additionally, the proposed hybrid transformed model is compared with the MILP-Mixed Integer Linear Programming model on the same data instances. For illustrative models, its use allowed finding optimal solutions eight to one hundred times faster and reducing the size of the combinatorial problem to a significant extent.

  3. Fused Lasso Additive Model.

    Science.gov (United States)

    Petersen, Ashley; Witten, Daniela; Simon, Noah

    2016-01-01

    We consider the problem of predicting an outcome variable using p covariates that are measured on n independent observations, in a setting in which additive, flexible, and interpretable fits are desired. We propose the fused lasso additive model (FLAM), in which each additive function is estimated to be piecewise constant with a small number of adaptively-chosen knots. FLAM is the solution to a convex optimization problem, for which a simple algorithm with guaranteed convergence to a global optimum is provided. FLAM is shown to be consistent in high dimensions, and an unbiased estimator of its degrees of freedom is proposed. We evaluate the performance of FLAM in a simulation study and on two data sets. Supplemental materials are available online, and the R package flam is available on CRAN.

  4. Alternative additives; Alternative additiver

    Energy Technology Data Exchange (ETDEWEB)

    2007-08-15

    In this project a number of industrial and agricultural waste products have been characterised and evaluated in terms of alkali-getter performance. The intended use is for biomass-fired power stations aiming at reducing corrosion or slagging related problems. The following products have been obtained, characterised and evaluated: 1) Brewery draff 2) Danish de-gassed manure 3) Paper sludge 4) Moulding sand 5) Spent bleaching earth 6) Anorthosite 7) Sand 8) Clay-sludge. Most of the above alternative additive candidates are deemed unsuitable due to insufficient chemical effect and/or expensive requirements for pre-treatment (such as drying and transportation). 3 products were selected for full-scale testing: de-gassed manure, spent bleaching earth and clay slugde. The full scale tests were undertaken at the biomass-fired power stations in Koege, Slagelse and Ensted. Spent bleaching earth (SBE) and clay sludge were the only tested additive candidates that had a proven ability to react with KCl, to thereby reduce Cl-concentrations in deposits, and reduce the deposit flux to superheater tubes. Their performance was shown to nearly as good as commercial additives. De-gassed manure, however, did not evaluate positively due to inhibiting effects of Ca in the manure. Furthermore, de-gassed manure has a high concentration of heavy metals, which imposes a financial burden with regard to proper disposal of the ash by-products. Clay-sludge is a wet clay slurring, and drying and transportation of this product entails substantial costs. Spent bleaching does not require much pre-treatment and is therefore the most promising alternative additive. On the other hand, bleaching earth contains residual plant oil which means that a range of legislation relating to waste combustion comes into play. Not least a waste combustion fee of 330 DKK/tonne. For all alternative (and commercial) additives disposal costs of the increase ash by-products represents a significant cost. This is

  5. From additivity to synergism

    DEFF Research Database (Denmark)

    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 antagonistic effects may be present. The statistical models are defined and explained and some of the approaches exemplified. Code in open-source software is provided....

  6. Additives in plastics.

    Science.gov (United States)

    Deanin, R D

    1975-01-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products. PMID:1175566

  7. Toward making the constraint hypersurface an attractor in free evolution

    International Nuclear Information System (INIS)

    Fiske, David R.

    2004-01-01

    When constructing numerical solutions to systems of evolution equations subject to a constraint, one must decide what role the constraint equations will play in the evolution system. In one popular choice, known as free evolution, a simulation is treated as a Cauchy problem, with the initial data constructed to satisfy the constraint equations. This initial data are then evolved via the evolution equations with no further enforcement of the constraint equations. The evolution, however, via the discretized evolution equations introduce constraint violating modes at the level of truncation error, and these constraint violating modes will behave in a formalism dependent way. This paper presents a generic method for incorporating the constraint equations into the evolution equations so that the off-constraint dynamics are biased toward the constraint satisfying solutions

  8. Hodgkin's disease: thyroid dysfunction following external irradiation

    International Nuclear Information System (INIS)

    Tamura, K.; Shimaoka, K.

    1981-01-01

    The thyroid gland is commonly included in the field of radiation therapy for patients with malignant lymphoma and with head and neck tumors. The radiation dose for malignant diseases varies considerably depending on the purpose of treatment and the institutional policies. A substantial number of these patients are developing subclinical and clinical hypothyroidism. The risk of developing hypothyroidism after a moderate radiation dose of 2000 to 4500 rads has been reported to be 10 to 20 percent. In addition, subclinical hypothyroidism is induced further in one third of the patients. There are also suggestions that external irradiation of the thyroid gland in patients with malignant lymphomas, as well as internal irradiation with radioiodine of the normal and hyperthyroid human thyroid glands, would induce elevations of serum antithyroid autoantibody titers. However, only a few cases of Graves disease following irradiation to the thyroid gland have been reported. We encountered a young woman who received radiation therapy to the mantle field for her Hodgkin's disease and developed hypothyroxinemia without overt signs and symptoms of hypothyroidism, followed by appearance of nodular goiter and then full-blown Graves disease

  9. External beam radiotherapy for rectal adenocarcinoma

    International Nuclear Information System (INIS)

    Taylor, R.E.; Kerr, G.R.; Arnott, S.J.

    1987-01-01

    A series of 243 patients with adenocarcinoma of the rectum treated with radiotherapy is presented. Radiotherapy was combined with 5-fluorouracil, or given alone. Seventy-four patients were treated with radical external beam radiotherapy for recurrent or inoperable rectal adenocarcinoma. One hundred and forty-five patients with advanced pelvic tumours or metastases were treated with palliative pelvic radiotherapy. Twenty-four patients with small-volume residual pelvic tumour or who were felt to be at high risk of pelvic recurrence following radical resection received postoperative radiotherapy. Complete tumour regression was seen in 38% of radically treated patients, and 24% of palliatively treated patients. Partial regression was observed in 56% of radically treated patients, and 58% of palliatively treated patients. Long-term local tumour control was more commonly observed for small tumours (< 5 cm diameter). Fifty-eight % of patients treated with postoperative radiotherapy remained free of local recurrence. Survival was significantly better with small tumours. The addition of 5FU did not appear to improve survival or tumour control. (author)

  10. Nonparametric instrumental regression with non-convex constraints

    Science.gov (United States)

    Grasmair, M.; Scherzer, O.; Vanhems, A.

    2013-03-01

    This paper considers the nonparametric regression model with an additive error that is dependent on the explanatory variables. As is common in empirical studies in epidemiology and economics, it also supposes that valid instrumental variables are observed. A classical example in microeconomics considers the consumer demand function as a function of the price of goods and the income, both variables often considered as endogenous. In this framework, the economic theory also imposes shape restrictions on the demand function, such as integrability conditions. Motivated by this illustration in microeconomics, we study an estimator of a nonparametric constrained regression function using instrumental variables by means of Tikhonov regularization. We derive rates of convergence for the regularized model both in a deterministic and stochastic setting under the assumption that the true regression function satisfies a projected source condition including, because of the non-convexity of the imposed constraints, an additional smallness condition.

  11. Nonparametric instrumental regression with non-convex constraints

    International Nuclear Information System (INIS)

    Grasmair, M; Scherzer, O; Vanhems, A

    2013-01-01

    This paper considers the nonparametric regression model with an additive error that is dependent on the explanatory variables. As is common in empirical studies in epidemiology and economics, it also supposes that valid instrumental variables are observed. A classical example in microeconomics considers the consumer demand function as a function of the price of goods and the income, both variables often considered as endogenous. In this framework, the economic theory also imposes shape restrictions on the demand function, such as integrability conditions. Motivated by this illustration in microeconomics, we study an estimator of a nonparametric constrained regression function using instrumental variables by means of Tikhonov regularization. We derive rates of convergence for the regularized model both in a deterministic and stochastic setting under the assumption that the true regression function satisfies a projected source condition including, because of the non-convexity of the imposed constraints, an additional smallness condition. (paper)

  12. Relationship between participation in leisure activities and constraints on Taiwanese breastfeeding mothers during leisure activities.

    Science.gov (United States)

    Chow, Hsueh-wen; Dong, Yin-Han

    2013-04-30

    Participation in leisure activities strongly associates with health and well-being. Little research has explored the relationship between participation in leisure activities and constraints on breastfeeding mothers during leisure activities. The purposes of this study are: 1) to investigate constraints on breastfeeding mothers during leisure activities and participation in leisure activities; 2) to investigate the differences between preferences for leisure activities and actual participation by breastfeeding mothers; 3) to segment breastfeeding mothers with similar patterns, using a cluster analysis based on the delineated participation in leisure activities and leisure preferences; 4) to explore any differences between clusters of breastfeeding mothers with respect to socio-demographic characteristics, breastfeeding behaviours and leisure constraints. This study has a cross-sectional design using an online survey conducted among mothers having breastfeeding experiences of more than four months. The questionnaire includes demographic variables, breastfeeding behaviours, preferences for leisure activities participation, and constraints on leisure activities. Collection of data occurred between March and July 2011, producing 415 valid responses for analysis. For breastfeeding mothers, this study identifies constraints on breastfeeding related to leisure activities in addition to the three traditional factors for constraints in the model. This study demonstrates that reports of constraints related to children, family, and nursing environments are the most frequent. Breastfeeding mothers in Taiwan participate regularly in family activities or activities related to their children. Cluster analysis classified breastfeeding mothers into Action and Contemplation groups, and found that mothers within the latter group participate less in leisure activities and experienced more constraints related to breastfeeding. Implications provide a developmental design for public

  13. Crossing boundaries : Involving external parties in innovation

    NARCIS (Netherlands)

    Slot, J.H.

    2013-01-01

    To improve the return on investments in innovation, firms increasingly open up their new product development (NPD) processes by inviting external parties to participate. This dissertation focuses on the involvement of three different types of external parties in the NPD process: suppliers,

  14. Hydropower externalities: A meta-analysis

    International Nuclear Information System (INIS)

    Mattmann, Matteo; Logar, Ivana; Brouwer, Roy

    2016-01-01

    This paper presents a meta-analysis of existing research related to the economic valuation of the external effects of hydropower. A database consisting of 81 observations derived from 29 studies valuing the non-market impacts of hydropower electricity generation is constructed with the main aim to quantify and explain the economic values for positive and negative hydropower externalities. Different meta-regression model specifications are used to test the robustness of significant determinants of non-market values, including different types of hydropower impacts. The explanatory and predictive power of the estimated models is relatively high. Whilst controlling for sample and study characteristics, we find significant evidence for public aversion towards deteriorations of landscape, vegetation and wildlife caused by hydropower projects. There is however only weak evidence of willingness to pay for mitigating these effects. The main positive externality of hydropower generation, the avoidance of greenhouse gas emission, positively influences welfare estimates when combined with the share of hydropower in national energy production. Sensitivity to scope is detected, but not linked to specific externalities or non-market valuation methods. - Highlights: • A global meta-analysis of valuation studies of hydropower externalities is presented. • Positive and negative externalities are distinguished. • Welfare losses due to environmental deteriorations outweigh gains of GHG reductions. • There is only weak evidence of public WTP for mitigating negative externalities. • The non-market values of hydropower externalities are sensitive to scope.

  15. School Improvement Processes and External Agency Roles.

    Science.gov (United States)

    Temkin, Sanford

    This paper discusses the improvement process used in schools to bring about change, as well as the influence of external agencies on improvement activity. It considers school district processes as they relate to improvement activity, the strategies and roles performed by external agencies, and the issues that might effect planning by an external…

  16. External Communities of Practice and Relational Capital

    Science.gov (United States)

    Dewhurst, Frank W.; Navarro, Juan G. Cegarra

    2004-01-01

    External communities of practice are groups formed by company clients and employees based on common interests, commitment, mutual trust and collaboration whose members regularly share knowledge and learning. This paper examines how external communities of practice contribute to the creation of relational capital through an empirical investigation…

  17. Black holes under external influence £

    Indian Academy of Sciences (India)

    KTF MFF UK

    Abstract. The work on black holes immersed in external fields is reviewed in both test-field ap- proximation and within exact solutions. In particular we pay attention to the effect of the expulsion of the flux of external fields across charged and rotating black holes which are approaching extremal states. Recently this effect has ...

  18. Forms of Spanking and Children's Externalizing Behaviors

    Science.gov (United States)

    Lansford, Jennifer E.; Wager, Laura B.; Bates, John E.; Pettit, Gregory S.; Dodge, Kenneth A.

    2012-01-01

    Research suggests that corporal punishment is related to higher levels of child externalizing behavior, but there has been controversy regarding whether infrequent, mild spanking predicts child externalizing or whether more severe and frequent forms of corporal punishment account for the link. Mothers rated the frequency with which they spanked…

  19. Wind power externalities: A meta-analysis

    NARCIS (Netherlands)

    Mattmann, M.; Logar, I.; Brouwer, R.

    2016-01-01

    This study presents the first quantitative meta-analysis of the non-market valuation literature on the external effects associated with wind power production. A data set of 60 observations drawn from 32 studies is constructed. The relative economic values of different types of externalities as well

  20. Examining the Assessment Literacy of External Examiners

    Science.gov (United States)

    Medland, Emma

    2015-01-01

    External scrutiny of higher education courses is evident globally, but the use of an external examiner from another institution for the purposes of quality assurance has been a distinguishing feature of UK higher education since the 1830s. However, the changing higher education context has led to mounting criticism of the system and the…