WorldWideScience

Sample records for arsine evolution methods

  1. Quantitative and qualitative trapping of arsines deployed to assess loss of volatile arsenic from paddy soil.

    Science.gov (United States)

    Mestrot, Adrien; Uroic, M Kalle; Plantevin, Thomas; Islam, Md Rafiqul; Krupp, Eva M; Feldmann, Jörg; Meharg, Andrew A

    2009-11-01

    Arsenic volatilization in the environment is thought to be an important pathway for transfer from terrestrial pools to the atmosphere. However, this phenomenon is not well characterized due to inherent sampling issues in trapping, quantifying and qualifying these arsine gases; including arsine (AsH(3)), monomethyl arsine (MeAsH(2)), dimethyl arsine (Me(2)AsH) and trimethyl arsine (TMAs). To quantify and qualify arsines in air we developed a novel technique based on silver nitrate impregnated silica gel filled tubes. The method was characterized by measuring the recovery of trapped arsines after elution of this chemo-trap with hot boiling diluted nitric acid. Results from three separate experiments, measured by ICP-MS, showed that the method is reproducible and quantitative. Arsine species recovery ranged from 80.1 to 95.6%, with limit of detection as low as 3.8 ng per chemo-trap tube. Moreover, HPLC-ICP-MS analysis of hot boiling water eluted traps showed that the corresponding oxy ions of the arsines were formed with the As-C bonds of the molecule intact, hence, allowing qualification of trapped arsine species. A microcosm study examining volatile arsenic evolution from field contaminated Bangladeshi paddy soils (24.2 mg/kg arsenic) was used to show the application of silver nitrate chemo-trapping approach. Traps were placed on the inlet and the outlet of microcosms containing the soils that were either (cattle derived) manured or not, or flooded or not, in a factorial design. The headspace was purged with air at a flow rate of 12 mL/min. Results showed that as much as 320 ng of arsenic (0.014% of total soil content) could be emitted in a 3 week period for manured and flooded soils and that TMAs was the dominant species evolved, with lesser quantities of Me(2)AsH. No volatile arsenic evolution was observed for nonmanured treatments, and arsine release from the nonflooded, manured treatment was much less than the flooded treatment.

  2. Catalytic Phosphination and Arsination

    Institute of Scientific and Technical Information of China (English)

    Kwong Fuk Yee; Chan Kin Shing

    2004-01-01

    The catalytic, user-friendly phosphination and arsination of aryl halides and triflates by triphenylphosphine and triphenylarsine using palladium catalysts have provided a facile synthesis of functionalized aryl phosphines and arsines in neutral media. Modification of the cynaoarisne yielded optically active N, As ligands which will be screened in various asymmetric catalysis.

  3. Arsine oxidation with heteropoly acid in the presence of halide ions

    Energy Technology Data Exchange (ETDEWEB)

    Dorfman, Ya.A.; Aleshkova, M.M.; Doroshkevich, D.M.; Kel' man, I.V. (AN Kazakhskoj SSR, Alma-Ata. Inst. Organicheskogo Kataliza i Ehlektrokhimii)

    1984-12-01

    Kinetics and mechanism of arsine oxidation by phosphomolybdovanadium heteropoly acid are studied in the presense of halide ions as catalysts. It is established that intrasphere arsine oxidation in an intermediate V(5) complex with AsH/sub 3/ and halide-ion is a limiting stage of the proposed mechanism. The quantum-chemical calculation of the electronic structure of intermediate complexes, which supports the above mechanism is carried out. The method of theoretical estimation of the activation energy is proposed.

  4. Arsine

    Science.gov (United States)

    ... too. Seal the bag, and then seal that bag inside another plastic bag. Disposing of your clothing in this way will ... arrange for further disposal. Do not handle the plastic bags yourself. For more information about cleaning your body ...

  5. Arsine and its fluoro, chloro derivatives: a computational thermochemical study

    Science.gov (United States)

    Bagchi, Sabyasachi; Mondal, Bhaskar; Ghosh, Deepanwita; Das, Abhijit K.

    2010-01-01

    The structures, vibrational frequencies, enthalpies of formation and dissociation energies of arsine, arsenic hydrides and their fluoro, chloro derivatives have been studied using density functional B3LYP/cc-pVDZ, ab-initio MP2/cc-pVDZ and composite CBS-QB3 and CBS-Q methods. Computed standard enthalpies of formation at 298 K by atomisation scheme are compared with reported values. Bond dissociation energies at 0 K are calculated for all possible thermal dissociation of the molecular species in gas phase, from which the energetically most favourable dissociation pathways are predicted. The calculated enthalpies of formation and bond dissociation energies are correlated with the nature of bonding in arsine and its fluoro, chloro derivatives. Energy barriers at 0 K are calculated and transition states are located for the molecular fragment elimination of the thermal dissociation reactions.

  6. Reactions of arsine with hemoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Hatlelid, K.M.; Brailsford, C.; Carter, D.E. [Univ. of Arizona, Tucson, AZ (United States)

    1996-02-09

    The mechanism of arsine (AsH{sub 3}) induced hemolysis was studied in vitro using isolated red blood cells (RBCs) from the rat or dog. AsH{sub 3}-induced hemolysis of dog red blood cells was completely blocked by carbon monoxide (CO) preincubation and was reduced by pure oxygen (O{sub 2}) compared to incubations in air. Since CO and O{sub 2} bind to heme and also reduced hemolysis, these results suggested a reaction between AsH{sub 3} and hemoglobin in the hemeligand binding pocket or with the heme iron. Further, sodium nitrite induction of methemoglobin (metHb) to 85% and 34% of total Hb in otherwise intact RBCs resulted in 56% and 16% decreases in hemolysis, respectively, after incubation for 4 h. This provided additional evidence for the involvement of hemoglobin in the AsH{sub 3}-induced hemolysis mechanism. Reactions between AsH{sub 3} and hemoglobin were studied in solutions of purified dog hemoglobin. Spectrophotometric studies of the reaction of AsH{sub 3} with various purified hemoglobin species revealed that AsH{sub 3} reacted with HbO{sub 2} to produce metHb and, eventually, degraded Hb characterized by gross precipitation of the protein. AsH{sub 3} did not alter the spectrum of deoxyHb and did not cause degradation of metHb in oxygen, but bound to and reduced metHb in the absence of oxygen. These data indicate that a reaction of AsH{sub 3} with oxygenated hemoglobin, HbO{sub 2}, may lead to hemolysis, but there are reactions between AsH{sub 3} and metHb that may not be directly involved in the hemolytic process. 17 refs., 6 figs.

  7. Acute arsine intoxication as a consequence of metal burnishing operations.

    Science.gov (United States)

    Romeo, L; Apostoli, P; Kovacic, M; Martini, S; Brugnone, F

    1997-09-01

    The report concerns a 30-year-old factory worker, employed in a small galvanizing plant for over ten years in the burnishing, copper- and nickel-plating of small metal articles for the shoe industry. Acute arsine poisoning was attributed to the use of a dilute solution of CuSO4 (3%), HCl (32%), and As2O3 (2%) for burnishing metal (Fe-Zn) shoelace eyelet holes, in the absence of local exhaust ventilation and with no respiratory protection. Arsine caused severe intravascular hemolysis with a rapid drop in hematocrit and hemoglobin levels. Other body organs were involved as a result of the hypoxic effect of anemia and hemolysis, or as a direct toxic effect of the arsine itself. Our experience confirms that exchange transfusion is capable of rapidly arresting the adverse effects of arsine. The importance of preventive measures and worker information to avoid acute arsine poisoning is emphasized.

  8. The Effect of Oxidation on the Surface Chemistry of Sulfur-Containing Carbons and their Arsine Adsorption Capacity

    Science.gov (United States)

    2010-01-01

    hydrogen sulfide . Carbon 2004;42(3):469–76. Fig. 6 – Water adsorption isotherms of the samples studied. 1786 C A R B O N 4 8 ( 2 0 1 0 ) 1 7 7 9 –1 7 8...that oxygen- and sulfur-containing groups participate in arsine oxida- tion to arsenic tri- and pentoxide and/or in the formation of arsenic sulfides ...technological difficulties, arsine is also a powerful toxin susceptible to oxidation with a strong exothermic effect. Of all the methods to separate

  9. Silver and gold nanocluster catalyzed reduction of methylene blue by arsine in micellar medium

    Indian Academy of Sciences (India)

    Subrata Kundu; Sujit Kumar Ghosh; Madhuri Mandal; Tarasankar Pal

    2002-11-01

    Arsenic can be determined in parts-per-million (ppm) level by absorbance measurement. This method is based on the quantitative colour bleaching of the dye, methylene blue by arsine catalyzed by nanoparticles in micellar medium. The arsine has been generated in situ from sodium arsenate by NaBH4 reduction. The absorbance measurement was carried out at the max of the dye at 660 nm. The calibration graph set-up for three linear dynamic ranges (LDR) are 0–8.63 ppm, 0–1.11 ppm and 0–0.11 ppm and limit of detections (LODs) are 1.3, 0.53 and 0.03 ppm, respectively. This method is simple, sensitive and easy to carry out. It is free from phosphate and silicate interference and applicable to real sample analysis.

  10. The role of arsine in the deactivation of methanol synthesis catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, R.; Mebrahtu, T.; Dahl, T.A.; Lucrezi, F.A.; Toseland, B.A. [Air Products and Chemicals Inc., Adsorption Technology Center, 7201 Hamilton Boulevard, Allentown, PA 18195-1501 (United States)

    2004-06-18

    The liquid phase methanol (LPMEOH) process is successfully producing methanol from coal-derived synthesis gas on an industrial scale. This process uses a standard copper, zinc oxide, and alumina catalyst suspended in an inert mineral oil in a slurry bubble column reactor. An arsenic-containing species, most reasonably arsine, was found in the feed to the LPMEOH commercial demonstration facility located at Eastman Chemical Company's chemicals-from-coal complex in Kingsport, TN. Laboratory testing showed that arsine is, in fact, a powerful methanol synthesis catalyst poison. At levels as low as 150ppbv, arsine results in a rapid deactivation of the catalyst. Removal of arsine results in a deactivation rate consistent with a clean synthesis gas feed; that is, arsine poisoning stops when it is removed from the feed. We infer that arsine reacts irreversibly with the catalyst under the methanol synthesis conditions. X-ray absorption spectroscopy (XAS) of arsenic-containing used catalyst indicated the presence of zero-valent arsenic in an intermetallic surface phase that is structurally related to Domeykite (Cu{sub 3}As). Experimental evidence, thermodynamics, and literature relating to other metal-arsine chemistry were consistent with dissociative adsorption of arsine on the copper surface to form gaseous H{sub 2} and Cu{sub 3}As. To deal with arsine poisoning, we have developed adsorption technology that can remove arsine to levels low enough that catalyst performance is unaffected.

  11. Suspected arsine poisoning during the restoration of a large cyclorama painting.

    Science.gov (United States)

    Williams, P L; Spain, W H; Rubenstein, M

    1981-12-01

    Arsine poisoning is a well-recognized phenomenon generally associated with the smelting and refining of metals. However, acute episodes of arsine poisoning do occur in environments unrelated to metal processing and often go unrecognized. The incident described herein, which deals with artists working on the restoration of a famous painting, illustrates that arsine gas may evolve in any situation where nascent hydrogen comes in contact with small amounts of arsenic.

  12. Stibine/arsine monitoring during EV operation: summary report on preliminary tests at ANL and at LILCO

    Energy Technology Data Exchange (ETDEWEB)

    Loutfy, R.O.; Graczyk, D.G.; Varma, R.; Hayes, E.R.; Williams, F.L.; Yao, N.P.

    1981-02-01

    A series of tests was performed to monitor the evolution and dispersal of stibine and arsine from the lead-acid propulsion batteries in three different Electra-Van Model 600 vehicles operated by Argonne National Laboratory (ANL) and by the Long Island Lighting Company (LILCO). Ambient air was sampled at several locations inside the vehicles and in the garages where testing was done during charge, equalization charge, and on-the-road discharge operations. In addition, direct sampling of cell off-gases was performed with the ANL van. Interpretation of the individual test results was carried out in the context of vehicle characteristics, sampling protocol, and operating conditions. The test results demonstrated that under the test conditions only small concentrations of stibine and arsine accumulated in occupiable work areas. Measured concentrations in the vehicles and in the garages never exceeded 25% of the Threshold Limit Value-Time Weighted Average (TLV-TWA) standards. A threshold voltage for hydride production, at about 2.45 V per cell, was reflected in the results of the experiments performed during charging of the batteries. Hydride evolution rates were lower during equalization charge than during the overcharge portion of a charge cycle when the on-board charger was used in a normal operating mode. A delayed release of the metal hydrides from the battery cells was observed during on-the-road operation of the vehicles. The implications of these observations for electric vehicle (EV) operation are discussed. An engineering analysis of the generation and dispersal of the metal hydrides is presented, and equations are derived for estimating minimum ventilation requirements for the EV battery compartment and for garages housing EV operations. Recommendations are made regarding safe handling procedures for battery off-gases, procedures for conducting stibine/arsine monitoring tests and future work.

  13. De acute arsine-intoxicatie. Richtlijnen voor opvang door EHBO'ers, ambulance-personeel en (bedrijfs)arts van slachtoffers van expositie aan arsine

    NARCIS (Netherlands)

    Remmert HP; Cremers PMA

    1987-01-01

    De gevaren verbonden aan de expositie aan arsine maken het wenselijk dat een protocol beschikbaar is waarbij minimaal de hoofdlijnen zijn aangegeven hoe bij dergelijke ongevallen te handelen. Dit document bevat een voorstel daartoe, waarin vooral aandacht is besteed aan de medische aspecten bij

  14. Novel Random Mutagenesis Method for Directed Evolution.

    Science.gov (United States)

    Feng, Hong; Wang, Hai-Yan; Zhao, Hong-Yan

    2017-01-01

    Directed evolution is a powerful strategy for gene mutagenesis, and has been used for protein engineering both in scientific research and in the biotechnology industry. The routine method for directed evolution was developed by Stemmer in 1994 (Stemmer, Proc Natl Acad Sci USA 91, 10747-10751, 1994; Stemmer, Nature 370, 389-391, 1994). Since then, various methods have been introduced, each of which has advantages and limitations depending upon the targeted genes and procedure. In this chapter, a novel alternative directed evolution method which combines mutagenesis PCR with dITP and fragmentation by endonuclease V is described. The kanamycin resistance gene is used as a reporter gene to verify the novel method for directed evolution. This method for directed evolution has been demonstrated to be efficient, reproducible, and easy to manipulate in practice.

  15. Evolutional Ant Colony Method Using PSO

    Science.gov (United States)

    Morii, Nobuto; Aiyoshi, Eitarou

    The ant colony method is one of heuristic methods capable of solving the traveling salesman problem (TSP), in which a good tour is generated by the artificial ant's probabilistic behavior. However, the generated tour length depends on the parameter describing the ant's behavior, and the best parameters corresponding to the problem to be solved is unknown. In this technical note, the evolutional strategy is presented to find the best parameter of the ant colony by using Particle Swarm Optimization (PSO) in the parameter space. Numerical simulations for benchmarks demonstrate effectiveness of the evolutional ant colony method.

  16. TAYLOR EXPANSION METHOD FOR NONLINEAR EVOLUTION EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    HE Yin-nian

    2005-01-01

    A new numerical method of integrating the nonlinear evolution equations, namely the Taylor expansion method, was presented. The standard Galerkin method can be viewed as the 0-th order Taylor expansion method; while the nonlinear Galerkin method can be viewed as the 1-st order modified Taylor expansion method. Moreover, the existence of the numerical solution and its convergence rate were proven. Finally, a concrete example,namely, the two-dimensional Navier-Stokes equations with a non slip boundary condition,was provided. The result is that the higher order Taylor expansion method is of the higher convergence rate under some assumptions about the regularity of the solution.

  17. Speciation analysis of arsenic compounds in the serum and urine of a patient with acute arsine poisoning

    Directory of Open Access Journals (Sweden)

    Yamanaka K.

    2013-04-01

    Full Text Available Arsine is one of the most potent hemolytic agents. It is important to clarify arsine metabolism as well as its chemical interactions with biological components. The aim of the present study was to clarify arsine metabolism by arsenic speciation analysis in serum and urine from an acute poisoning patient with hematuria, anemia, and renal and liver dysfunction. Speciation analysis of arsenics in serum and urine was performed using HPLC-ICP-MS. The total arsenic (T-As concentration in serum was 244.8 μg/l at admission and 97.1 μg/l at discharge. In the speciation analysis, four kinds of As compounds derived from arsine metabolism were detected in serum and urine. The concentration of arsenite (AsIII, arsenate (AsV, monomethylarsonic acid (MMA, and dimethylarsinic acid (DMA in serum at admission were 45.8, 5.2, 17.9 and 9.3 μg/l, respectively. The concentrations of AsIII, AsV, and MMA decreased with biological half time (BHT of 30.1, 43.0, and 96.3 h, respectively. Only DMA was increased at discharge. The urinary AsIII, AsV, MMA and DMA concentrations were 223.0, 12.1, 317.5 and 1053.5 μg/l at discharge, and decreased with BHT of 15.1, 20.8, 14.7, and 16.0 d, respectively. The results indicate that arsine was quickly metabolized to AsIII and subsequently up to DMA, with the result that the toxic effects of inorganic arsenic were added to those of arsine toxicity.

  18. Black hole evolution by spectral methods

    CERN Document Server

    Kidder, L E; Teukolsky, S A; Carlson, E D; Cook, G B; Kidder, Lawrence E.; Scheel, Mark A.; Teukolsky, Saul A.; Carlson, Eric D.; Cook, Gregory B.

    2000-01-01

    Current methods of evolving a spacetime containing one or more black holes are plagued by instabilities that prohibit long-term evolution. Some of these instabilities may be due to the numerical method used, traditionally finite differencing. In this paper, we explore the use of a pseudospectral collocation (PSC) method for the evolution of a spherically symmetric black hole spacetime in one dimension using a hyperbolic formulation of Einstein's equations. We demonstrate that our PSC method is able to evolve a spherically symmetric black hole spacetime forever without enforcing constraints, even if we add dynamics via a Klein-Gordon scalar field. We find that, in contrast to finite-differencing methods, black hole excision is a trivial operation using PSC applied to a hyperbolic formulation of Einstein's equations. We discuss the extension of this method to three spatial dimensions.

  19. Evolution of OO Methods: the unified case

    Directory of Open Access Journals (Sweden)

    Matti Rossi

    1997-05-01

    Full Text Available This paper takes an evaluative look into OO methods and especially the evolution of the new snified method from its ancestors, OMT and OODA. The paper ries to classify the components of the earlier ethods and identify the parts that have been taken into the Unified ethod. The research applies the method metrics approach. For the sake of compactness we limit ourselves to the class diagram technique of all methods. We make observations about the number of concepts in each variation and show how the metrics can be used to analyse the changes in the techniques.

  20. Oxidation state-differentiated measurement of aqueous inorganic arsenic by continuous flow electrochemical arsine generation coupled to gas-phase chemiluminescence detection.

    Science.gov (United States)

    Sengupta, Mrinal K; Dasgupta, Purnendu K

    2011-12-15

    The electrochemical reduction of inorganic As on a graphite cathode depends on the current density. We observed that while only inorganic As(III) is reduced to AsH(3) at low current densities, at high current densities both forms of inorganic As are reduced. We describe a unique electrochemical reactor in which the cylindrical anode compartment is isolated from the outer concentric cathode compartment by a Nafion tube in which a hole is deliberately made and the entire anode compartment is inside the cylindrical cavity of a small volume (∼115 μL) cathode chamber. The evolved arsine is then quantitated by gas-phase chemiluminescence (GPCL) reaction with ozone; the latter is generated from oxygen formed during electrolysis. For the dimensions used, inorganic As(III) can be selectively determined at a current of 0.1 A while total inorganic As (both As(III) and As(V)) respond equally at an applied electrolysis current at 0.85 A, without any sample treatment. For a 1-mL sample, the system provides a limit of detection (LOD, S/N = 3) of 0.09 μg/L for total As (i = 0.85 A) and an LOD of 0.76 μg/L for As(III) (i = 0.10 A); As(V) is obtained by difference. Comparison of ICP-MS results for total As in groundwater samples that span a large range of concentration and total inorganic As determined by the present method showed a high correlation (r(2) = 0.9975) and a near unity slope. The basic electrochemical arsine generation technique and current-differentiated oxidation state speciation should be applicable as the front end to many other arsenic measurements techniques, including atomic spectrometry.

  1. Sequence Hiberarchy Evolution Measurement Method and its Application

    Institute of Scientific and Technical Information of China (English)

    Jian Ding QIU; Ru Ping LIANG; Jin Yuan MO; Xiao Yong ZOU

    2005-01-01

    A novel method based on discrete wavelet transform (DWT) and cross-covariance for revealing the evolution of species at different spatial resolutions is presented. The trypsin proteins of different species are chosen as an example to describe the evolution relationship according to the evolution vectors by using this method. The results indicated that this method is a promising approach to reveal species evolution at different spatial resolutions.

  2. Facial Beautification Method Based on Age Evolution

    Institute of Scientific and Technical Information of China (English)

    CHEN Yan; DING Shou-hong; HU Gan-le; MA Li-zhuang

    2013-01-01

    This paper proposes a new facial beautification method using facial rejuvenation based on the age evolution. Traditional facial beautification methods only focus on the color of skin and deformation and do the transformation based on an experimental standard of beauty. Our method achieves the beauty effect by making facial image looks younger, which is different from traditional methods and is more reasonable than them. Firstly, we decompose the image into different layers and get a detail layer. Secondly, we get an age-related parameter:the standard deviation of the Gaussian distribution that the detail layer follows, and the support vector machine (SVM) regression is used to fit a function about the age and the standard deviation. Thirdly, we use this function to estimate the age of input image and generate a new detail layer with a new standard deviation which is calculated by decreasing the age. Lastly, we combine the original layers and the new detail layer to get a new face image. Experimental results show that this algo-rithm can make facial image become more beautiful by facial rejuvenation. The proposed method opens up a new way about facial beautification, and there are great potentials for applications.

  3. Evolution of genotoxicity test methods in Japan.

    Science.gov (United States)

    Sofuni, Toshio

    2017-01-01

    The evolution of methods to assess genotoxicity of test compounds is thought to be one of the important subjects in The Japanese Environmental and Mutagen Society (JEMS). In 1970, the Ministry of Education of Japan (at that time) organized a research group (Organizer: Y. Tazima, National Institute of Genetics), and started a systematic research on the genotoxic effects induced by chemical substances. Considering the importance of this issue through the outcomes of the research group, JEMS was established in 1972, and President Tazima organized the 1st annual meeting in the August in Tokyo with the participation of experts in this field working in national institutes, universities and others in Japan. The discovery that food additives possessed genotoxic potential triggered various scientific activities in the field of genotoxicity. Another important point was the correlation between genotoxicity and carcinogenicity, in which the establishment of the reverse mutation assay played an important role. Other critical factors, such as side effects of drugs, occupational cancer, and environmental pollution due to genotoxic chemicals, emphasized the importance of genotoxicity tests for human safety. The tests performed to assess genotoxicity from 1960s to 1980s will be described to understand that many different genotoxic methodologies were discussed in these periods.

  4. Infrared Evolution Equations: Method and Applications

    OpenAIRE

    Ermolaev, B. I.; Greco, M; Troyan, S. I.

    2007-01-01

    It is a brief review on composing and solving Infrared Evolution Equations. They can be used in order to calculate amplitudes of high-energy reactions in different kinematic regions in the double-logarithmic approximation.

  5. Multivariate regression analysis on influencing factors related to arsenic content in urine of arsine exposed workers%砷化氢作业工人尿中砷含量相关因素的多元线性回归分析

    Institute of Scientific and Technical Information of China (English)

    韦光毅; 柳元; 胡天桥; 陈启玲

    2012-01-01

    目的 分析寻找砷化氢作业工人的尿中砷含量的主要影响因素,为预防砷化氢中毒提供参考.方法 收集132例砷化氢作业工人的尿砷水平及其相关因素的详细资料,采用多元逐步回归和多元线性回归的方法进行统计分析.结果 获得回归方程lgY=0.551 D1+0.281 D2 +0.665X7+0.059X8+0.005 X3 -2.279,决定系数调整R2=0.885,其中D1,D2代表工种的2个虚拟变量,X7代表砷化氢浓度,X8代表自觉症状,X3代表年龄,标准化偏回归系数分别为0.569,0.268,0.624,0.056,0.054.结论 回归方程表明砷化氢作业工人尿砷的主要影响因素为工种、砷化氢浓度,提示预防砷化氢中毒要做好高危工种工人的防护,控制好作业场所空气中砷化氢的浓度.%[ Objective ] To analyze the major factors affecting arsenic levels in urine of workers exposed to arsine, and provide reference for arsine poisoning prevention. [ Methods] Detailed information on arsenic levels in urine and its related factors of 132 cases of workers exposed to arsine was collected. Stepwise multiple regression and multiple linear regression method were used for statistical analysis. [Results] Regression equation was obtained, lg Y = 0. 551 D1 +0. 281 D2 +0. 665 X, + 0. 059 X2 +0. 005 X3-2. 279, adjusted R2 =0. 885, D, , D2 were the two dummy variables of jobs, X7 was the concentration of arsine, X8 was symptoms, X3 was the age. Their standardized partial regression coefficients were 0. 569, 0. 268, 0. 624, 0. 056 and 0. 054. [ Conclusion] The regression equation suggests the main factors affecting arsenic levels in urine of workers exposed to arsine were the types of work and the concentration of arsine, the protection of high-risk workers and the control of air arsine concentration in workplaces should be strengthened.

  6. Semigroup methods for evolution equations on networks

    CERN Document Server

    Mugnolo, Delio

    2014-01-01

    This concise text is based on a series of lectures held only a few years ago and originally intended as an introduction to known results on linear hyperbolic and parabolic equations.  Yet the topic of differential equations on graphs, ramified spaces, and more general network-like objects has recently gained significant momentum and, well beyond the confines of mathematics, there is a lively interdisciplinary discourse on all aspects of so-called complex networks. Such network-like structures can be found in virtually all branches of science, engineering and the humanities, and future research thus calls for solid theoretical foundations.      This book is specifically devoted to the study of evolution equations – i.e., of time-dependent differential equations such as the heat equation, the wave equation, or the Schrödinger equation (quantum graphs) – bearing in mind that the majority of the literature in the last ten years on the subject of differential equations of graphs has been devoted to ellip...

  7. Developing Unconstrained Methods for Enzyme Evolution

    Science.gov (United States)

    2014-09-19

    methods fail to produce catalytically efficient enzymes. This study has broad application in many technologies from chemical synthesis to human health and...enzymes. This study has broad application in many technologies from chemical synthesis to human health and the environment. Our work centers around the...minimal media with N-15 labeled ammonia . After several months of screening, we finally identified conditions that allowed us to obtain labeled protein in

  8. Construction Method of Supernetwork Evolution Model

    Institute of Scientific and Technical Information of China (English)

    LIU; Qiang; FANG; Jin-qing; LI; Yong

    2013-01-01

    Real networks often have small-world and scale-free characteristics.Based on BA and WS model,we proposed the following construction method for TLSEM(Fig.1).Three layers are BA model(TBA),three layers are SW model(TSW),the first and third layers are BA model,the middle layer is SW model(BA-SW),the first and third layers are SW model,and the middle layer is BA model(SW-BA).The

  9. Method of Analytic Evolution of Flat Distribution Amplitudes in QCD

    CERN Document Server

    Tandogan, Asli

    2011-01-01

    A new analytical method of performing ERBL evolution is described. The main goal is to develop an approach that works for distribution amplitudes that do not vanish at the end points, for which the standard method of expansion in Gegenbauer polynomials is inefficient. Two cases of the initial DA are considered: a purely flat DA, given by the same constant for all x, and an antisymmetric DA given by opposite constants for x 1/2. For a purely flat DA, the evolution is governed by an overall (x (1-x))^t dependence on the evolution parameter t times a factor that was calculated as an expansion in t. For an antisymmetric flat DA, an extra overall factor |1-2x|^{2t} appears due to a jump at x=1/2. A good convergence was observed in the t < 1/2 region. For larger t, one can use the standard method of the Gegenbauer expansion.

  10. Failure Analysis of Wind Turbines by Probability Density Evolution Method

    DEFF Research Database (Denmark)

    Sichani, Mahdi Teimouri; Nielsen, Søren R.K.; Liu, W.F.

    2013-01-01

    The aim of this study is to present an efficient and accurate method for estimation of the failure probability of wind turbine structures which work under turbulent wind load. The classical method for this is to fit one of the extreme value probability distribution functions to the extracted maxima....... This is not practical due to its excessive computational load. This problem can alternatively be tackled if the evolution of the probability density function (PDF) of the response process can be realized. The evolutionary PDF can then be integrated on the boundaries of the problem. For this reason we propose to use...... the Probability Density Evolution Method (PDEM). PDEM can alternatively be used to obtain the distribution of the extreme values of the response process by simulation. This approach requires less computational effort than integrating the evolution of the PDF; but may be less accurate. In this paper we present...

  11. Evolution of Research Methods for Probing and Understanding Metacognition

    Science.gov (United States)

    Anderson, David; Nashon, Samson M.; Thomas, Gregory P.

    2009-01-01

    This paper reports on the development, self-critique and evolution of research methods for interpreting and understanding students' metacognition that were developed through the Metacognition and Reflective Inquiry (MRI) collaborative study. The MRI collaborative was a multi-year, multi-case, research study that investigated the elusive nature and…

  12. Silica-Supported Arsine Palladium(0) Complex: a Highly Active and Stereoselective Catalyst for Arylation of Butyl Acrylate and Acrylamide

    Institute of Scientific and Technical Information of China (English)

    蔡明中; 赵红; 胡文英

    2005-01-01

    A silica-supported arsine palladium(O) complex has been prepared from y-chloropropyltriethoxysilane via immobilization on fumed silica, followed by reaction with potassium diphenylarsenide and palladium chloride, and then reduction with hydrazine hydrate. The complex has been characterized by X-ray photoelectron spectroscopy (XPS) and it is a highly active and stereoselective catalyst for arylation of butyl acrylate and acrylamide with aryl halides, affording a variety of tram-butyl cinnamates and trans-cinnamamides in high yields.

  13. Finite Volume Evolution Galerkin Methods for Nonlinear Hyperbolic Systems

    Science.gov (United States)

    Lukáčová-Medvid'ová, M.; Saibertová, J.; Warnecke, G.

    2002-12-01

    We present new truly multidimensional schemes of higher order within the frame- work of finite volume evolution Galerkin (FVEG) methods for systems of nonlinear hyperbolic conservation laws. These methods couple a finite volume formulation with approximate evolution operators. The latter are constructed using the bicharacteristics of the multidimensional hyperbolic system, such that all of the infinitely many directions of wave propagation are taken into account. Following our previous results for the wave equation system, we derive approximate evolution operators for the linearized Euler equations. The integrals along the Mach cone and along the cell interfaces are evaluated exactly, as well as by means of numerical quadratures. The influence of these numerical quadratures will be discussed. Second-order resolution is obtained using a conservative piecewise bilinear recovery and the midpoint rule approximation for time integration. We prove error estimates for the finite volume evolution Galerkin scheme for linear systems with constant coefficients. Several numerical experiments for the nonlinear. Euler equations, which confirm the accuracy and good multidimensional behavior of the FVEG schemes, are presented as well.

  14. Time evolution of the wave equation using rapid expansion method

    KAUST Repository

    Pestana, Reynam C.

    2010-07-01

    Forward modeling of seismic data and reverse time migration are based on the time evolution of wavefields. For the case of spatially varying velocity, we have worked on two approaches to evaluate the time evolution of seismic wavefields. An exact solution for the constant-velocity acoustic wave equation can be used to simulate the pressure response at any time. For a spatially varying velocity, a one-step method can be developed where no intermediate time responses are required. Using this approach, we have solved for the pressure response at intermediate times and have developed a recursive solution. The solution has a very high degree of accuracy and can be reduced to various finite-difference time-derivative methods, depending on the approximations used. Although the two approaches are closely related, each has advantages, depending on the problem being solved. © 2010 Society of Exploration Geophysicists.

  15. Study of nanoscale damage evolution using embedded atom method potentials

    Science.gov (United States)

    Potirniche, Gabriel; Horstemeyer, Mark; Gullet, Phillip

    2004-03-01

    Damage evolution at nanoscale has been studied using embedded atom method (EAM) potentials based on molecular dynamics principles. The simulations were performed using WARP, a parallel computing atomistic stress simulator based on Lennard-Jones (LJ) potentials for Aluminum. By varying the number of atoms from a few hundred to a few hundred thousands, we analyzed void nucleation, growth and coalescence at increasing material length scale. Rectangular specimens with and without voids were subjected to uniaxial tension up to a total strain of 50rates. Uniaxial stress-strain curves, void-volume fraction evolution and stress triaxiality were monitored. The results indicated that nucleation process is highly dependent on the material length scale, while the void growth and void coalescence mechanisms were almost indifferent to the increasing length scale. Material length scale mostly affects dislocation nucleation mechanisms that lead to void formation. Strain rate also significantly influences the stress-strain response during plastic deformation at various length scales.

  16. ImOSM: intermittent evolution and robustness of phylogenetic methods.

    Science.gov (United States)

    Thi Nguyen, Minh Anh; Gesell, Tanja; von Haeseler, Arndt

    2012-02-01

    Among the criteria to evaluate the performance of a phylogenetic method, robustness to model violation is of particular practical importance as complete a priori knowledge of evolutionary processes is typically unavailable. For studies of robustness in phylogenetic inference, a utility to add well-defined model violations to the simulated data would be helpful. We therefore introduce ImOSM, a tool to imbed intermittent evolution as model violation into an alignment. Intermittent evolution refers to extra substitutions occurring randomly on branches of a tree, thus changing alignment site patterns. This means that the extra substitutions are placed on the tree after the typical process of sequence evolution is completed. We then study the robustness of widely used phylogenetic methods: maximum likelihood (ML), maximum parsimony (MP), and a distance-based method (BIONJ) to various scenarios of model violation. Violation of rates across sites (RaS) heterogeneity and simultaneous violation of RaS and the transition/transversion ratio on two nonadjacent external branches hinder all the methods recovery of the true topology for a four-taxon tree. For an eight-taxon balanced tree, the violations cause each of the three methods to infer a different topology. Both ML and MP fail, whereas BIONJ, which calculates the distances based on the ML estimated parameters, reconstructs the true tree. Finally, we report that a test of model homogeneity and goodness of fit tests have enough power to detect such model violations. The outcome of the tests can help to actually gain confidence in the inferred trees. Therefore, we recommend using these tests in practical phylogenetic analyses.

  17. Molecular Phylogenetic: Organism Taxonomy Method Based on Evolution History

    Directory of Open Access Journals (Sweden)

    N.L.P Indi Dharmayanti

    2011-03-01

    Full Text Available Phylogenetic is described as taxonomy classification of an organism based on its evolution history namely its phylogeny and as a part of systematic science that has objective to determine phylogeny of organism according to its characteristic. Phylogenetic analysis from amino acid and protein usually became important area in sequence analysis. Phylogenetic analysis can be used to follow the rapid change of a species such as virus. The phylogenetic evolution tree is a two dimensional of a species graphic that shows relationship among organisms or particularly among their gene sequences. The sequence separation are referred as taxa (singular taxon that is defined as phylogenetically distinct units on the tree. The tree consists of outer branches or leaves that represents taxa and nodes and branch represent correlation among taxa. When the nucleotide sequence from two different organism are similar, they were inferred to be descended from common ancestor. There were three methods which were used in phylogenetic, namely (1 Maximum parsimony, (2 Distance, and (3 Maximum likehoood. Those methods generally are applied to construct the evolutionary tree or the best tree for determine sequence variation in group. Every method is usually used for different analysis and data.

  18. A Direct Algebraic Method in Finding Particular Solutions to Some Nonlinear Evolution Equations

    Institute of Scientific and Technical Information of China (English)

    LIUChun-Ping; CHENJian-Kang; CAIFan

    2004-01-01

    Firstly, a direct algebraic method and a routine way in finding traveling wave solutions to nonlinear evolution equations are explained. And then some new exact solutions for some evolution equations are obtained by using the method.

  19. New method to study DNA sequences: the languages of evolution.

    Science.gov (United States)

    Spinelli, Gino; Mayer-Foulkes, David

    2008-04-01

    Recently, several authors have reported statistical evidence for deterministic dynamics in the flux of genetic information, suggesting that evolution involves the emergence and maintenance of a fractal landscape in DNA chains. Here we examine the idea that motif repetition lies at the origin of these statistical properties of DNA. To analyse repetition patterns we apply a modification of the BDS statistic, devised to analyze complex economic dynamics and adapted here to DNA sequence analysis. This provides a new method to detect structured signals in genetic information. We compare naturally occurring DNA sequences along the evolutionary tree with randomly generated sequences and also with simulated sequences with repetition motifs. For easier understanding, we also define a new statistic for a DNA sequence that constitutes a specific fingerprint. The new methods are applied to exon and intron DNA sequences, finding specific statistical differences. Moreover, by analysing DNA sequences of different species from Bacteria to Man, we explore the evolution of these linguistic DNA features along the evolutionary tree. The results are consistent with the idea that all the flux of DNA information need not be random, but may be structured along the evolutionary tree. The implications for evolutionary theory are discussed.

  20. The early evolution of Jean Piaget's clinical method.

    Science.gov (United States)

    Mayer, Susan Jean

    2005-11-01

    This article analyzes the early evolution of Jean Piaget's renowned "clinical method" in order to investigate the method's strikingly original and generative character. Throughout his 1st decade in the field, Piaget frequently discussed and justified the many different approaches to data collection he used. Analysis of his methodological progression during this period reveals that Piaget's determination to access the genuine convictions of children eventually led him to combine 3 distinct traditions in which he had been trained-naturalistic observation, psychometrics, and the psychiatric clinical examination. It was in this amalgam, first evident in his 4th text, that Piaget discovered the clinical dynamic that would drive the classic experiments for which he is most well known.

  1. Extremal Optimization: Methods Derived from Co-Evolution

    Energy Technology Data Exchange (ETDEWEB)

    Boettcher, S.; Percus, A.G.

    1999-07-13

    We describe a general-purpose method for finding high-quality solutions to hard optimization problems, inspired by self-organized critical models of co-evolution such as the Bak-Sneppen model. The method, called Extremal Optimization, successively eliminates extremely undesirable components of sub-optimal solutions, rather than ''breeding'' better components. In contrast to Genetic Algorithms which operate on an entire ''gene-pool'' of possible solutions, Extremal Optimization improves on a single candidate solution by treating each of its components as species co-evolving according to Darwinian principles. Unlike Simulated Annealing, its non-equilibrium approach effects an algorithm requiring few parameters to tune. With only one adjustable parameter, its performance proves competitive with, and often superior to, more elaborate stochastic optimization procedures. We demonstrate it here on two classic hard optimization problems: graph partitioning and the traveling salesman problem.

  2. Ruthenium(II) carbonyl complexes containing chalconates and triphenylphosphine/arsine

    Indian Academy of Sciences (India)

    P Viswanathamurthi; M Muthukumar

    2011-09-01

    A series of new hexa-coordinated ruthenium(II) carbonyl complexes of the type [RuCl(CO)(EPh3)(B)(L1−4)] (4-15) (E = P or As; B = PPh3, AsPh3 or Py; L = 2'-hydroxychalcone) were synthesized from the reaction of [RuHCl(CO)(EPh3)2(B)] (1-3) (E = P or As; B = PPh3, AsPh3 or Py) with equimolar chalcone in benzene under reflux. The new complexes have been characterized by analytical and spectroscopic (IR, electronic, 1H, 31P{1H}, and 13C NMR) methods. On the basis of data obtained, an octahedral structure has been assigned for all the complexes. The complexes exhibit catalytic activity for the oxidation of primary and secondary alcohols into their corresponding aldehydes and ketones in the presence of -methylmorpholine--oxide (NMO) as co-oxidant and were also found to be efficient transfer hydrogenation catalysts. The antifungal properties of the ligands and their complexes have also been examined and compared with standard Bavistin.

  3. Quasistatic Evolution in Debonding Problems via Capacitary Methods

    Science.gov (United States)

    Bucur, Dorin; Buttazzo, Giuseppe; Lux, Anne

    2008-09-01

    We discuss quasistatic evolution processes for capacitary measures and shapes in order to model debonding membranes. Minimizing movements as well as rate-independent processes are investigated and some models are described, together with a series of open problems.

  4. Finite volume evolution Galerkin (FVEG) methods for hyperbolic systems

    OpenAIRE

    Lukácová-Medvid'ová, Maria; Morton, K.W.; Warnecke, Gerald

    2003-01-01

    The subject of the paper is the derivation and analysis of new multidimensional, high-resolution, finite volume evolution Galerkin (FVEG) schemes for systems of nonlinear hyperbolic conservation laws. Our approach couples a finite volume formulation with approximate evolution operators. The latter are constructed using the bicharacteristics of the multidimensional hyperbolic system, such that all of the infinitely many directions of wave propagation are taken into account. In particular, we p...

  5. The Generalized Projective Riccati Equations Method for Solving Nonlinear Evolution Equations in Mathematical Physics

    Directory of Open Access Journals (Sweden)

    E. M. E. Zayed

    2014-01-01

    Full Text Available We apply the generalized projective Riccati equations method to find the exact traveling wave solutions of some nonlinear evolution equations with any-order nonlinear terms, namely, the nonlinear Pochhammer-Chree equation, the nonlinear Burgers equation and the generalized, nonlinear Zakharov-Kuznetsov equation. This method presents wider applicability for handling many other nonlinear evolution equations in mathematical physics.

  6. Analytic treatment of nonlinear evolution equations using first integral method

    Indian Academy of Sciences (India)

    Ahmet Bekir; Ömer Ünsal

    2012-07-01

    In this paper, we show the applicability of the first integral method to combined KdV-mKdV equation, Pochhammer–Chree equation and coupled nonlinear evolution equations. The power of this manageable method is confirmed by applying it for three selected nonlinear evolution equations. This approach can also be applied to other nonlinear differential equations.

  7. The nonsinglet structure function evolution by Laplace method

    Energy Technology Data Exchange (ETDEWEB)

    Boroun, G. R., E-mail: grboroun@gmail.com, E-mail: boroun@razi.ac.ir; Zarrin, S. [Razi University, Physics Department (Iran, Islamic Republic of)

    2015-12-15

    We derive a general scheme for the evolution of the nonsinglet structure function at the leadingorder (LO) and next-to-leading-order (NLO) by using the Laplace-transform technique. Results for the nonsinglet structure function are compared with MSTW2008, GRV, and CKMT parameterizations and also EMC experimental data in the LO and NLO analysis. The results are in good agreement with the experimental data and other parameterizations in the low- and large-x regions.

  8. Genetic-evolution-based optimization methods for engineering design

    Science.gov (United States)

    Rao, S. S.; Pan, T. S.; Dhingra, A. K.; Venkayya, V. B.; Kumar, V.

    1990-01-01

    This paper presents the applicability of a biological model, based on genetic evolution, for engineering design optimization. Algorithms embodying the ideas of reproduction, crossover, and mutation are developed and applied to solve different types of structural optimization problems. Both continuous and discrete variable optimization problems are solved. A two-bay truss for maximum fundamental frequency is considered to demonstrate the continuous variable case. The selection of locations of actuators in an actively controlled structure, for minimum energy dissipation, is considered to illustrate the discrete variable case.

  9. The evolution of methods for establishing evolutionary timescales

    Science.gov (United States)

    2016-01-01

    The fossil record is well known to be incomplete. Read literally, it provides a distorted view of the history of species divergence and extinction, because different species have different propensities to fossilize, the amount of rock fluctuates over geological timescales, as does the nature of the environments that it preserves. Even so, patterns in the fossil evidence allow us to assess the incompleteness of the fossil record. While the molecular clock can be used to extend the time estimates from fossil species to lineages not represented in the fossil record, fossils are the only source of information concerning absolute (geological) times in molecular dating analysis. We review different ways of incorporating fossil evidence in modern clock dating analyses, including node-calibrations where lineage divergence times are constrained using probability densities and tip-calibrations where fossil species at the tips of the tree are assigned dates from dated rock strata. While node-calibrations are often constructed by a crude assessment of the fossil evidence and thus involves arbitrariness, tip-calibrations may be too sensitive to the prior on divergence times or the branching process and influenced unduly affected by well-known problems of morphological character evolution, such as environmental influence on morphological phenotypes, correlation among traits, and convergent evolution in disparate species. We discuss the utility of time information from fossils in phylogeny estimation and the search for ancestors in the fossil record. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’. PMID:27325838

  10. A systematic approximate method for the study of evolution problem beyond rotating wave approximation

    Institute of Scientific and Technical Information of China (English)

    Zhang Zheng-Jie; Wang Ke-Lin; Qin Gan

    2005-01-01

    By a model of atwo-level particle coupled with boson field, we made it clear that an evolution problem can be solved beyond the rotating wave approximation. We have applied the coherent approximation method, which had been proved to be effective in dealing with stationary state problems of polaron, to the evolution problem of the system mentioned above. The results obtained showed that the coherent approximation method is effective to treat the evolution problem,and, in general cases, the non-rotating wave terms in Hamiltonian should not be ignored. Our results may provide a deep physical insight for further experiments to test the effects of non-rotating wave terms.

  11. Well-balanced finite volume evolution Galerkin methods for the shallow water equations

    OpenAIRE

    Medvidová, Maria Lukáčová -; Noelle, Sebastian; Kraft, Marcus

    2015-01-01

    We present a new well-balanced finite volume method within the framework of the finite volume evolution Galerkin (FVEG) schemes. The methodology will be illustrated for the shallow water equations with source terms modelling the bottom topography and Coriolis forces. Results can be generalized to more complex systems of balance laws. The FVEG methods couple a finite volume formulation with approximate evolution operators. The latter are constructed using the bicharacteristics of multidimensio...

  12. Well-balanced finite volume evolution Galerkin methods for the shallow water equations

    OpenAIRE

    Lukácová-Medvid'ová, Maria; Kraft, Marcus

    2005-01-01

    We present a new well-balanced finite volume method within the framework of the finite volume evolution Galerkin (FVEG) schemes. The methodology will be illustrated for the shallow water equations with source terms modelling the bottom topography and Coriolis forces. Results can be generalized to more complex systems of balance laws. The FVEG methods couple a finite volume formulation with approximate evolution operators. The latter are constructed using the bicharacteristics of the multidime...

  13. Evolution of microbiological analytical methods for dairy industry needs

    Directory of Open Access Journals (Sweden)

    Daniele eSohier

    2014-02-01

    Full Text Available Traditionally, culture-based methods have been used to enumerate microbial populations in dairy products. Recent developments in molecular methods now enable faster and more sensitive analyses than classical microbiology procedures. These molecular tools allow a detailed characterization of cell physiological states and bacterial fitness and thus, offer new perspectives to integration of microbial physiology monitoring to improve industrial processes. This review summarizes the methods described to enumerate and characterize physiological states of technological microbiota in dairy products, and discusses the current deficiencies in relation to the industry’s needs. Recent studies show that PCR-based methods can successfully be applied to quantify fermenting microbes and probiotics in dairy products. Flow cytometry and omics technologies also show interesting analytical potentialities. However, they still suffer from a lack of validation and standardization for quality control analyses, as reflected by the absence of performance studies and official international standards.

  14. Plastic evolution behavior of H340LAD_Z steel by an optical method

    Science.gov (United States)

    Guo, Nan; Liang, Jin; Yu, Qiang; Qian, Boxing

    2017-02-01

    An optical method based on digital image correlation (DIC) technology was proposed to measure the plastic evolution of the high-strength low alloy steel H340LAD_Z. The basic principle of DIC technology is introduced, and then, the use of a 3D deformation measurement system and electronic universal testing machine to dynamically measure plastic evolution during the tensile yield stage is described. Through the full-field full-process measurement of plastic deformation during the yield stage in the 0°, 45° and 90° loading directions, the plastic evolution law was revealed. The results demonstrate that the proposed 3D DIC method can accurately reveal the starting and ending times for plastic evolution. The specimens in the three directions exhibit different plastic evolution behaviors, although they have similar yield strengths and yield times. The specimens in the 45° and 90° loading directions began to enter plastic deformation from bottom to top and the plastic area was maintained in a constant deformed state, while the evolution behavior in the 0° direction transited from both sides to the middle and plastic deformation was uneven. It is important to study plastic evolution of a metal sheet to determine the material properties and to provide an accurate basis for finite element modeling.

  15. Vinayaka : A Semi-Supervised Projected Clustering Method Using Differential Evolution

    OpenAIRE

    Satish Gajawada; Durga Toshniwal

    2012-01-01

    Differential Evolution (DE) is an algorithm for evolutionary optimization. Clustering problems have beensolved by using DE based clustering methods but these methods may fail to find clusters hidden insubspaces of high dimensional datasets. Subspace and projected clustering methods have been proposed inliterature to find subspace clusters that are present in subspaces of dataset. In this paper we proposeVINAYAKA, a semi-supervised projected clustering method based on DE. In this method DE opt...

  16. Evolution of Hydrogen Storage Alloys Prepared by Special Methods

    Institute of Scientific and Technical Information of China (English)

    Guo Hong; Zhang Ximin; Jing Hai; Li Chengdong; Xu Jun

    2004-01-01

    Microstructure characteristics and electrochemical properties of hydrogen storage alloys prepared by gas atomization, melt spinning and strip casting respectively were outlined.The advantages, disadvantages and research development of the above methods for preparing hydrogen storage alloys were explained.The strip casting is a new special means for preparing AB5 rare earth hydrogen storage alloys of high performance and low cost, and the study of the strip casting for preparing hydrogen storage alloys is presented specially.

  17. Extended Riccati Equation Rational Expansion Method and Its Application to Nonlinear Stochastic Evolution Equations

    Institute of Scientific and Technical Information of China (English)

    WANG Mei-Jiao; WANG Qi

    2006-01-01

    In this work, by means of a new more general ansatz and the symbolic computation system Maple, we extend the Riccati equation rational expansion method [Chaos, Solitons & Fractals 25 (2005) 1019] to uniformly construct a series of stochastic nontravelling wave solutions for nonlinear stochastic evolution equation. To illustrate the effectiveness of our method, we take the stochastic mKdV equation as an example, and successfully construct some new and more general solutions including a series of rational formal nontraveling wave and coefficient functions' soliton-like solutions and trigonometric-like function solutions. The method can also be applied to solve other nonlinear stochastic evolution equation or equations.

  18. Evolution of dispersive liquid-liquid microextraction method.

    Science.gov (United States)

    Rezaee, Mohammad; Yamini, Yadollah; Faraji, Mohammad

    2010-04-16

    Dispersive liquid-liquid microextraction (DLLME) has become a very popular environmentally benign sample-preparation technique, because it is fast, inexpensive, easy to operate with a high enrichment factor and consumes low volume of organic solvent. DLLME is a modified solvent extraction method in which acceptor-to-donor phase ratio is greatly reduced compared with other methods. In this review, in order to encourage further development of DLLME, its combination with different analytical techniques such as gas chromatography (GC), high-performance liquid chromatography (HPLC), inductively coupled plasma-optical emission spectrometry (ICP-OES) and electrothermal atomic absorption spectrometry (ET AAS) will be discussed. Also, its applications in conjunction with different extraction techniques such as solid-phase extraction (SPE), solidification of floating organic drop (SFO) and supercritical fluid extraction (SFE) are summarized. This review focuses on the extra steps in sample preparation for application of DLLME in different matrixes such as food, biological fluids and solid samples. Further, the recent developments in DLLME are presented. DLLME does have some limitations, which will also be discussed in detail. Finally, an outlook on the future of the technique will be given.

  19. A Generalized F-expansion Method and Its Application in High-Dimensional Nonlinear Evolution Equation

    Institute of Scientific and Technical Information of China (English)

    CHEN Jiang; HE Hong-Sheng; YANG Kong-Qing

    2005-01-01

    A generalized F-expansion method is introduced and applied to (3+ 1)-dimensional Kadomstev-Petviashvili(KP) equation. As a result, some new Jacobi elliptic function solutions of the equation are found, from which the trigonometric function solutions and the solitary wave solutions can be obtained. The method can also be extended to other types of nonlinear evolution equations in mathematical physics.

  20. Application of the trial equation method for solving some nonlinear evolution equations arising in mathematical physics

    Indian Academy of Sciences (India)

    Yusuf Gurefe; Abdullah Sonmezoglu; Emine Misirli

    2011-12-01

    In this paper some exact solutions including soliton solutions for the KdV equation with dual power law nonlinearity and the (, ) equation with generalized evolution are obtained using the trial equation method. Also a more general trial equation method is proposed.

  1. The evolution of analytical chemistry methods in foodomics.

    Science.gov (United States)

    Gallo, Monica; Ferranti, Pasquale

    2016-01-08

    The methodologies of food analysis have greatly evolved over the past 100 years, from basic assays based on solution chemistry to those relying on the modern instrumental platforms. Today, the development and optimization of integrated analytical approaches based on different techniques to study at molecular level the chemical composition of a food may allow to define a 'food fingerprint', valuable to assess nutritional value, safety and quality, authenticity and security of foods. This comprehensive strategy, defined foodomics, includes emerging work areas such as food chemistry, phytochemistry, advanced analytical techniques, biosensors and bioinformatics. Integrated approaches can help to elucidate some critical issues in food analysis, but also to face the new challenges of a globalized world: security, sustainability and food productions in response to environmental world-wide changes. They include the development of powerful analytical methods to ensure the origin and quality of food, as well as the discovery of biomarkers to identify potential food safety problems. In the area of nutrition, the future challenge is to identify, through specific biomarkers, individual peculiarities that allow early diagnosis and then a personalized prognosis and diet for patients with food-related disorders. Far from the aim of an exhaustive review of the abundant literature dedicated to the applications of omic sciences in food analysis, we will explore how classical approaches, such as those used in chemistry and biochemistry, have evolved to intersect with the new omics technologies to produce a progress in our understanding of the complexity of foods. Perhaps most importantly, a key objective of the review will be to explore the development of simple and robust methods for a fully applied use of omics data in food science.

  2. Finite volume evolution Galerkin method for hyperbolic conservation laws with spatially varying flux functions

    Science.gov (United States)

    Arun, K. R.; Kraft, M.; Lukáčová-Medvid'ová, M.; Prasad, Phoolan

    2009-02-01

    We present a generalization of the finite volume evolution Galerkin scheme [M. Lukáčová-Medvid'ová, J. Saibertov'a, G. Warnecke, Finite volume evolution Galerkin methods for nonlinear hyperbolic systems, J. Comp. Phys. (2002) 183 533- 562; M. Lukáčová-Medvid'ová, K.W. Morton, G. Warnecke, Finite volume evolution Galerkin (FVEG) methods for hyperbolic problems, SIAM J. Sci. Comput. (2004) 26 1-30] for hyperbolic systems with spatially varying flux functions. Our goal is to develop a genuinely multi-dimensional numerical scheme for wave propagation problems in a heterogeneous media. We illustrate our methodology for acoustic waves in a heterogeneous medium but the results can be generalized to more complex systems. The finite volume evolution Galerkin (FVEG) method is a predictor-corrector method combining the finite volume corrector step with the evolutionary predictor step. In order to evolve fluxes along the cell interfaces we use multi-dimensional approximate evolution operator. The latter is constructed using the theory of bicharacteristics under the assumption of spatially dependent wave speeds. To approximate heterogeneous medium a staggered grid approach is used. Several numerical experiments for wave propagation with continuous as well as discontinuous wave speeds confirm the robustness and reliability of the new FVEG scheme.

  3. Evolution of accelerometer methods for physical activity research.

    Science.gov (United States)

    Troiano, Richard P; McClain, James J; Brychta, Robert J; Chen, Kong Y

    2014-07-01

    The technology and application of current accelerometer-based devices in physical activity (PA) research allow the capture and storage or transmission of large volumes of raw acceleration signal data. These rich data not only provide opportunities to improve PA characterisation, but also bring logistical and analytic challenges. We discuss how researchers and developers from multiple disciplines are responding to the analytic challenges and how advances in data storage, transmission and big data computing will minimise logistical challenges. These new approaches also bring the need for several paradigm shifts for PA researchers, including a shift from count-based approaches and regression calibrations for PA energy expenditure (PAEE) estimation to activity characterisation and EE estimation based on features extracted from raw acceleration signals. Furthermore, a collaborative approach towards analytic methods is proposed to facilitate PA research, which requires a shift away from multiple independent calibration studies. Finally, we make the case for a distinction between PA represented by accelerometer-based devices and PA assessed by self-report.

  4. A Bivariate Chebyshev Spectral Collocation Quasilinearization Method for Nonlinear Evolution Parabolic Equations

    Directory of Open Access Journals (Sweden)

    S. S. Motsa

    2014-01-01

    Full Text Available This paper presents a new method for solving higher order nonlinear evolution partial differential equations (NPDEs. The method combines quasilinearisation, the Chebyshev spectral collocation method, and bivariate Lagrange interpolation. In this paper, we use the method to solve several nonlinear evolution equations, such as the modified KdV-Burgers equation, highly nonlinear modified KdV equation, Fisher's equation, Burgers-Fisher equation, Burgers-Huxley equation, and the Fitzhugh-Nagumo equation. The results are compared with known exact analytical solutions from literature to confirm accuracy, convergence, and effectiveness of the method. There is congruence between the numerical results and the exact solutions to a high order of accuracy. Tables were generated to present the order of accuracy of the method; convergence graphs to verify convergence of the method and error graphs are presented to show the excellent agreement between the results from this study and the known results from literature.

  5. A bivariate Chebyshev spectral collocation quasilinearization method for nonlinear evolution parabolic equations.

    Science.gov (United States)

    Motsa, S S; Magagula, V M; Sibanda, P

    2014-01-01

    This paper presents a new method for solving higher order nonlinear evolution partial differential equations (NPDEs). The method combines quasilinearisation, the Chebyshev spectral collocation method, and bivariate Lagrange interpolation. In this paper, we use the method to solve several nonlinear evolution equations, such as the modified KdV-Burgers equation, highly nonlinear modified KdV equation, Fisher's equation, Burgers-Fisher equation, Burgers-Huxley equation, and the Fitzhugh-Nagumo equation. The results are compared with known exact analytical solutions from literature to confirm accuracy, convergence, and effectiveness of the method. There is congruence between the numerical results and the exact solutions to a high order of accuracy. Tables were generated to present the order of accuracy of the method; convergence graphs to verify convergence of the method and error graphs are presented to show the excellent agreement between the results from this study and the known results from literature.

  6. Standard test methods for arsenic in uranium hexafluoride

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 These test methods are applicable to the determination of total arsenic in uranium hexafluoride (UF6) by atomic absorption spectrometry. Two test methods are given: Test Method A—Arsine Generation-Atomic Absorption (Sections 5-10), and Test Method B—Graphite Furnace Atomic Absorption (Appendix X1). 1.2 The test methods are equivalent. The limit of detection for each test method is 0.1 μg As/g U when using a sample containing 0.5 to 1.0 g U. Test Method B does not have the complete collection details for precision and bias data thus the method appears as an appendix. 1.3 Test Method A covers the measurement of arsenic in uranyl fluoride (UO2F2) solutions by converting arsenic to arsine and measuring the arsine vapor by flame atomic absorption spectrometry. 1.4 Test Method B utilizes a solvent extraction to remove the uranium from the UO2F2 solution prior to measurement of the arsenic by graphite furnace atomic absorption spectrometry. 1.5 Both insoluble and soluble arsenic are measured when UF6 is...

  7. Trial Equation Method to Nonlinear Evolution Equations with Rank Inhomogeneous:Mathematical Discussions and Its Applications

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A trial equation method to nonlinear evolution equation with rank inhomogeneous is given. As applications, the exact traveling wave solutions to some higher-order nonlinear equations such as generalized Boussinesq equation,generalized Pochhammer-Chree equation, KdV-Burgers equation, and KS equation and so on, are obtained. Among these, some results are new. The proposed method is based on the idea of reduction of the order of ODE. Some mathematical details of the proposed method are discussed.

  8. Study of Simulation Method of Time Evolution of Atomic and Molecular Systems by Quantum Electrodynamics

    CERN Document Server

    Ichikawa, Kazuhide; Tachibana, Akitomo

    2014-01-01

    We discuss a method to follow step-by-step time evolution of atomic and molecular systems based on QED (Quantum Electrodynamics). Our strategy includes expanding the electron field operator by localized wavepackets to define creation and annihilation operators and following the time evolution using the equations of motion of the field operator in the Heisenberg picture. We first derive a time evolution equation for the excitation operator, the product of two creation or annihilation operators, which is necessary for constructing operators of physical quantities such as the electronic charge density operator. We then describe our approximation methods to obtain time differential equations of the electronic density matrix, which is defined as the expectation value of the excitation operator. By solving the equations numerically, we show "electron-positron oscillations", the fluctuations originated from virtual electron-positron pair creations and annihilations, appear in the charge density of a hydrogen atom an...

  9. Periodic Solutions of Evolution Variational Inequalities-a Method of Guiding Functions

    Institute of Scientific and Technical Information of China (English)

    Samir ADLY; Daniel GOELEVEN; Michel TH(E)RA

    2009-01-01

    This paper focuses on a part of the presentation given by the third author at the Shanghai Forum on Industrial and Applied Mathematics (Shanghai 2006). It is related to the existence of a periodic solution of evolution variational inequalities. The approach is based on the method of guiding functions.

  10. Modeling of the evolution of steppe chernozems and development of the method of pedogenetic chronology

    DEFF Research Database (Denmark)

    Lisetskii, F.N.; Stolba, Vladimir; Goleusov, P.V.

    2016-01-01

    Geoarchaeological methods were used to study chronosequences of surface soils in the steppe zone and to trace soil evolution during the Late Holocene in northwestern Crimea. It was found that the morphological and functional “maturity” of the humus horizons in steppe chernozems of the Late Holocene...

  11. A new method of research on molecular evolution of pro-teinase superfamily

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The molecular evolutionary tree, also known as a phylogenetic tree, of the serine proteinase superfamily was constructed by means of structural alignment. Three-dimensional structures of proteins were aligned by the SSAP program of Orengo and Taylor to obtain evolutionary dis-tances. The resulting evolutionary tree provides a topology graph that can reflect the evolution of structure and function of homology proteinase. Moreover, study on evolution of the serine proteinase superfamily can lead to better under-standing of the relationship and evolutionary difference among proteins of the superfamily, and is of significance to protein engineering, molecular design and protein structure prediction. Structure alignment is one of the useful methods of research on molecular evolution of protein.

  12. Application of Exp-function method for nonlinear evolution equations with variable coefficients

    Energy Technology Data Exchange (ETDEWEB)

    El-Wakil, S.A.; Madkour, M.A. [Theoretical Research Group, Physics Department, Faculty of Science, Mansoura University, 35516 Mansoura (Egypt); Abdou, M.A. [Theoretical Research Group, Physics Department, Faculty of Science, Mansoura University, 35516 Mansoura (Egypt); Faculty of Education for Girls, Physics Department, King Kahlid University, Bisha, Kingdom Saudi Arabia (Saudi Arabia)], E-mail: m_abdou_eg@yahoo.com

    2007-09-10

    In this Letter, the Exp-function method with the aid of symbolic computational system Maple is used to obtain generalized solitary solutions and periodic solutions of a generalized Zakharov-Kuznetsov equation with variable coefficients. It is shown that the Exp-function method, with the help of symbolic computation, provides a powerful mathematical tool for solving other nonlinear evolution equations arising in mathematical physics.

  13. A New Generalization of Extended Tanh-Function Method for Solving Nonlinear Evolution Equations

    Institute of Scientific and Technical Information of China (English)

    ZHENG Xue-Dong; CHEN Yong; LI Biao; ZHANG Hong-Qing

    2003-01-01

    Making use of a new generalized ansatze and a proper transformation, we generalized the extended tanh-function method. Applying the generalized method with the aid of Maple, we consider some nonlinear evolution equations.As a result, we can successfully recover the previously known solitary wave solutions that had been found by the extendedtanh-function method and other more sophisticated methods. More importantly, for some equations, we also obtain othernew and more general solutions at the same time. The results include kink-profile solitary-wave solutions, bell-profilesolitary-wave solutions, periodic wave solutions, rational solutions, singular solutions and new formal solutions.

  14. On the Bivariate Spectral Homotopy Analysis Method Approach for Solving Nonlinear Evolution Partial Differential Equations

    Directory of Open Access Journals (Sweden)

    S. S. Motsa

    2014-01-01

    Full Text Available This paper presents a new application of the homotopy analysis method (HAM for solving evolution equations described in terms of nonlinear partial differential equations (PDEs. The new approach, termed bivariate spectral homotopy analysis method (BISHAM, is based on the use of bivariate Lagrange interpolation in the so-called rule of solution expression of the HAM algorithm. The applicability of the new approach has been demonstrated by application on several examples of nonlinear evolution PDEs, namely, Fisher’s, Burgers-Fisher’s, Burger-Huxley’s, and Fitzhugh-Nagumo’s equations. Comparison with known exact results from literature has been used to confirm accuracy and effectiveness of the proposed method.

  15. The finite volume local evolution Galerkin method for solving the hyperbolic conservation laws

    Science.gov (United States)

    Sun, Yutao; Ren, Yu-Xin

    2009-07-01

    This paper presents a finite volume local evolution Galerkin (FVLEG) scheme for solving the hyperbolic conservation laws. The FVLEG scheme is the simplification of the finite volume evolution Galerkin method (FVEG). In FVEG, a necessary step is to compute the dependent variables at cell interfaces at tn + τ (0 FVEG. The FVLEG scheme greatly simplifies the evaluation of the numerical fluxes. It is also well suited with the semi-discrete finite volume method, making the flux evaluation being decoupled with the reconstruction procedure while maintaining the genuine multi-dimensional nature of the FVEG methods. The derivation of the FVLEG scheme is presented in detail. The performance of the proposed scheme is studied by solving several test cases. It is shown that FVLEG scheme can obtain very satisfactory numerical results in terms of accuracy and resolution.

  16. Multiple (′/)-expansion method and its applications to nonlinear evolution equations in mathematical physics

    Indian Academy of Sciences (India)

    Junchao Chen; Biao Li

    2012-03-01

    In this paper, an extended multiple (′/)-expansion method is proposed to seek exact solutions of nonlinear evolution equations. The validity and advantages of the proposed method is illustrated by its applications to the Sharma–Tasso–Olver equation, the sixth-order Ramani equation, the generalized shallow water wave equation, the Caudrey–Dodd–Gibbon–Sawada–Kotera equation, the sixth-order Boussinesq equation and the Hirota–Satsuma equations. As a result, various complexiton solutions consisting of hyperbolic functions, trigonometric functions, rational functions and their mixture with parameters are obtained. When some parameters are taken as special values, the known double solitary-like wave solutions are derived from the double hyperbolic function solution. In addition, this method can also be used to deal with some high-dimensional and variable coefficients’ nonlinear evolution equations.

  17. Development of efficient time-evolution method based on three-term recurrence relation

    Energy Technology Data Exchange (ETDEWEB)

    Akama, Tomoko, E-mail: a.tomo---s-b-l-r@suou.waseda.jp; Kobayashi, Osamu; Nanbu, Shinkoh, E-mail: shinkoh.nanbu@sophia.ac.jp [Department of Materials and Life Science, Faculty of Science and Technology, Sophia University, Tokyo 102-8554 (Japan)

    2015-05-28

    The advantage of the real-time (RT) propagation method is a direct solution of the time-dependent Schrödinger equation which describes frequency properties as well as all dynamics of a molecular system composed of electrons and nuclei in quantum physics and chemistry. Its applications have been limited by computational feasibility, as the evaluation of the time-evolution operator is computationally demanding. In this article, a new efficient time-evolution method based on the three-term recurrence relation (3TRR) was proposed to reduce the time-consuming numerical procedure. The basic formula of this approach was derived by introducing a transformation of the operator using the arcsine function. Since this operator transformation causes transformation of time, we derived the relation between original and transformed time. The formula was adapted to assess the performance of the RT time-dependent Hartree-Fock (RT-TDHF) method and the time-dependent density functional theory. Compared to the commonly used fourth-order Runge-Kutta method, our new approach decreased computational time of the RT-TDHF calculation by about factor of four, showing the 3TRR formula to be an efficient time-evolution method for reducing computational cost.

  18. Dynamic and Quantitative Method of Analyzing Service Consistency Evolution Based on Extended Hierarchical Finite State Automata

    Directory of Open Access Journals (Sweden)

    Linjun Fan

    2014-01-01

    Full Text Available This paper is concerned with the dynamic evolution analysis and quantitative measurement of primary factors that cause service inconsistency in service-oriented distributed simulation applications (SODSA. Traditional methods are mostly qualitative and empirical, and they do not consider the dynamic disturbances among factors in service’s evolution behaviors such as producing, publishing, calling, and maintenance. Moreover, SODSA are rapidly evolving in terms of large-scale, reusable, compositional, pervasive, and flexible features, which presents difficulties in the usage of traditional analysis methods. To resolve these problems, a novel dynamic evolution model extended hierarchical service-finite state automata (EHS-FSA is constructed based on finite state automata (FSA, which formally depict overall changing processes of service consistency states. And also the service consistency evolution algorithms (SCEAs based on EHS-FSA are developed to quantitatively assess these impact factors. Experimental results show that the bad reusability (17.93% on average is the biggest influential factor, the noncomposition of atomic services (13.12% is the second biggest one, and the service version’s confusion (1.2% is the smallest one. Compared with previous qualitative analysis, SCEAs present good effectiveness and feasibility. This research can guide the engineers of service consistency technologies toward obtaining a higher level of consistency in SODSA.

  19. New generalized and improved (G′/G-expansion method for nonlinear evolution equations in mathematical physics

    Directory of Open Access Journals (Sweden)

    Hasibun Naher

    2014-10-01

    Full Text Available In this article, new extension of the generalized and improved (G′/G-expansion method is proposed for constructing more general and a rich class of new exact traveling wave solutions of nonlinear evolution equations. To demonstrate the novelty and motivation of the proposed method, we implement it to the Korteweg-de Vries (KdV equation. The new method is oriented toward the ease of utilize and capability of computer algebraic system and provides a more systematic, convenient handling of the solution process of nonlinear equations. Further, obtained solutions disclose a wider range of applicability for handling a large variety of nonlinear partial differential equations.

  20. Traveling wave solutions of nonlinear evolution equations via the enhanced (G′/G-expansion method

    Directory of Open Access Journals (Sweden)

    Kamruzzaman Khan

    2014-07-01

    Full Text Available In this article, an enhanced (G′/G-expansion method is suggested to find the traveling wave solutions for the modified Korteweg de-Vries (mKDV equation. Abundant traveling wave solutions are derived, which are expressed by the hyperbolic and trigonometric functions involving several parameters. The efficiency of this method for finding these exact solutions has been demonstrated. It is shown that the proposed method is effective and can be used for many other nonlinear evolution equations (NLEEs in mathematical physics.

  1. Well-balanced finite volume evolution Galerkin methods for the shallow water equations

    Science.gov (United States)

    Lukáčová-Medvid'ová, M.; Noelle, S.; Kraft, M.

    2007-01-01

    We present a new well-balanced finite volume method within the framework of the finite volume evolution Galerkin (FVEG) schemes. The methodology will be illustrated for the shallow water equations with source terms modelling the bottom topography and Coriolis forces. Results can be generalized to more complex systems of balance laws. The FVEG methods couple a finite volume formulation with approximate evolution operators. The latter are constructed using the bicharacteristics of multidimensional hyperbolic systems, such that all of the infinitely many directions of wave propagation are taken into account explicitly. We derive a well-balanced approximation of the integral equations and prove that the FVEG scheme is well-balanced for the stationary steady states as well as for the steady jets in the rotational frame. Several numerical experiments for stationary and quasi-stationary states as well as for steady jets confirm the reliability of the well-balanced FVEG scheme.

  2. Modeling community succession and assembly: A novel method for network evolution

    Directory of Open Access Journals (Sweden)

    WenJun Zhang

    2012-06-01

    Full Text Available The process of modeling community succession and assembly is in some sense a method for network evolution, as done by Barabasi and Albert (1999. It is also one of the methods to create a sample networkfrom the statistic network I proposed earlier. I think that the mechanism of network evolution supposed by Barabasi and Albert is most likely applicable to the natural phenomena with emergency property. For natural phenomena without emergency property, the present study indicated that a scale-free network may be produced through a new mechanism, i.e., whether the connection of a taxon x occurs, dependent on the type and property of taxon y (in particular, the degree of its direct correlation with x to be connected but not necessarily the existing number of connections of taxon y, as proposed in present study.

  3. Evolution of forced shear flows in polytropic atmospheres: A comparison of forcing methods and energetics

    CERN Document Server

    Witzke, V; Favier, B

    2016-01-01

    Shear flows are ubiquitous in astrophysical objects including planetary and stellar interiors, where their dynamics can have significant impact on thermo-chemical processes. Investigating the complex dynamics of shear flows requires numerical calculations that provide a long time evolution of the system. To achieve a sufficiently long lifetime in a local numerical model the system has to be forced externally. However, at present, there exist several different forcing methods to sustain large-scale shear flows in local models. In this paper we examine and compare various methods used in the literature in order to resolve their respective applicability and limitations. These techniques are compared during the exponential growth phase of a shear flow instability, such as the Kelvin-Helmholtz (KH) instability, and some are examined during the subsequent non-linear evolution. A linear stability analysis provides reference for the growth rate of the most unstable modes in the system and a detailed analysis of the e...

  4. Finite volume evolution Galerkin (FVEG) methods for three-dimensional wave equation system

    OpenAIRE

    Lukácová-Medvid'ová, Maria; Warnecke, Gerald; Zahaykah, Yousef

    2004-01-01

    The subject of the paper is the derivation of finite volume evolution Galerkin schemes for three-dimensional wave equation system. The aim is to construct methods which take into account all of the infinitely many directions of propagation of bicharacteristics. The idea is to evolve the initial function using the characteristic cone and then to project onto a finite element space. Numerical experiments are presented to demonstrate the accuracy and the multidimensional behaviour of the solutio...

  5. Similarity Renormalization Group Evolution of Nucleon-Nucleon Interactions in the Subtracted Kernel Method Approach

    Energy Technology Data Exchange (ETDEWEB)

    Szpigel, S. [Centro de Ciencias e Humanidades, Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil); Timoteo, V.S. [Faculdade de Tecnologia, Universidade Estadual de Campinas, Limeira, SP (Brazil); Duraes, F. de O [Centro de Ciencias e Humanidades, Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil)

    2010-02-15

    In this work we study the Similarity Renormalization Group (SRG) evolution of effective nucleon-nucleon (NN) interactions derived using the Subtracted Kernel Method (SKM) approach. We present the results for the phaseshifts in the {sup 1}S{sub 0} channel calculated using a SRG potential evolved from an initial effective potential obtained by implementing the SKM scheme for the leading-order NN interaction in chiral effective field theory (ChEFT).

  6. Evolution of forced shear flows in polytropic atmospheres: a comparison of forcing methods and energetics

    Science.gov (United States)

    Witzke, V.; Silvers, L. J.; Favier, B.

    2016-11-01

    Shear flows are ubiquitous in astrophysical objects including planetary and stellar interiors, where their dynamics can have significant impact on thermochemical processes. Investigating the complex dynamics of shear flows requires numerical calculations that provide a long-time evolution of the system. To achieve a sufficiently long lifetime in a local numerical model, the system has to be forced externally. However, at present, there exist several different forcing methods to sustain large-scale shear flows in local models. In this paper, we examine and compare various methods used in the literature in order to resolve their respective applicability and limitations. These techniques are compared during the exponential growth phase of a shear flow instability, such as the Kelvin-Helmholtz (KH) instability, and some are examined during the subsequent non-linear evolution. A linear stability analysis provides reference for the growth rate of the most unstable modes in the system and a detailed analysis of the energetics provides a comprehensive understanding of the energy exchange during the system's evolution. Finally, we discuss the pros and cons of each forcing method and their relation with natural mechanisms generating shear flows.

  7. Evolution Methods of Formation of Neuronet Models of Complex Economic Systems

    Directory of Open Access Journals (Sweden)

    Khemelyov Oleksandr H.

    2014-01-01

    Full Text Available The article analyses principles of formation of neuronet models of complex economic systems. It justifies prospectiveness of use of artificial intellect methods when modelling complex economic systems. It shows a possibility of use of evolution methods when forming neuronet models of complex economic systems for ensuring invariance of their generalising properties. It offers an algorithm with a genome from operons of fixed length. It considers all operons from the point of view of functional positions. It notes a specific feature of the algorithm, which allows excluding anthropogenic factors when selecting the neuronet models architecture. It proves adequacy of the formed neuronet models of complex economic systems.

  8. Evolution of self-reporting methods for identifying discrete emotions in science classrooms

    Science.gov (United States)

    Ritchie, Stephen M.; Hudson, Peter; Bellocchi, Alberto; Henderson, Senka; King, Donna; Tobin, Kenneth

    2016-09-01

    Emotion researchers have grappled with challenging methodological issues in capturing emotions of participants in naturalistic settings such as school or university classrooms. Self-reporting methods have been used frequently, yet these methods are inadequate when used alone. We argue that the self-reporting methods of emotion diaries and cogenerative dialogues can be helpful in identifying in-the-moment emotions when used in conjunction with the microanalysis of video recordings of classroom events. We trace the evolution of our use of innovative self-reporting methods through three cases from our research projects, and propose new directions for our ongoing development and application of these methods in both school and university classrooms.

  9. Decoupling the NLO coupled QED $\\otimes$ QCD, DGLAP evolution equations,Using Laplace Transform Method

    CERN Document Server

    Mottaghizadeh, Marzieh; Taghavi-Shahri, Fatemeh

    2016-01-01

    We analytically solved the QED $\\otimes$ QCD coupled DGLAP evolution equations at leading order (LO) quantum electrodynamics (QED) and next to leading order (NLO) quantum chromodynamics (QCD) approximations, using the Laplace transform method and then computed the proton structure function in terms of the unpolarized parton distributions functions. Our analyitical solutions for parton densities are in good agreement with those from APFEL (A PDF Evolution Library) (Computer Physics Communications 185, 1647-1668 (2014)) and CT14QED (Phys. Rev. D 93, 114015 (2016)) global parameterizations. We also compared the proton structure function, $F_{2}^{p}(x,Q^{2})$, with experimental data released by the ZEUS and H1 collaborations at HERA. There is a nice agreement between them in the range of low and high x and $Q^{2}$.

  10. Tracking evolution of myoglobin stability in cetaceans using experimentally calibrated computational methods that account for generic protein relaxation

    DEFF Research Database (Denmark)

    Holm, Jeppe; Dasmeh, Pouria; Kepp, Kasper Planeta

    2016-01-01

    The evolution of cetaceans (whales, dolphins, and porpoises) from land to water is one of the most spectacular events in mammal evolution. It has been suggested that selection for higher myoglobin stability (ΔG of folding) allowed whales to conquer the deep-diving niche. The stability of multi...... that predicts multi-site ΔΔG as accurately as standard methods do for single-site mutations and reproduces trends in contemporary myoglobin stabilities. We then apply this new method to the study of the evolution of Mb stability in cetaceans: With both methods the main change in stability (about 1 kcal....../mol) occurred very early, and stability was later relaxed in dolphins and porpoises, but was further increased in the sperm whales. This suggests that single proteins can affect whole organism evolution and indicates a role of Mb stability in the evolution of cetaceans. Transition to the deep-diving niche...

  11. A nonparametric statistical method for image segmentation using information theory and curve evolution.

    Science.gov (United States)

    Kim, Junmo; Fisher, John W; Yezzi, Anthony; Cetin, Müjdat; Willsky, Alan S

    2005-10-01

    In this paper, we present a new information-theoretic approach to image segmentation. We cast the segmentation problem as the maximization of the mutual information between the region labels and the image pixel intensities, subject to a constraint on the total length of the region boundaries. We assume that the probability densities associated with the image pixel intensities within each region are completely unknown a priori, and we formulate the problem based on nonparametric density estimates. Due to the nonparametric structure, our method does not require the image regions to have a particular type of probability distribution and does not require the extraction and use of a particular statistic. We solve the information-theoretic optimization problem by deriving the associated gradient flows and applying curve evolution techniques. We use level-set methods to implement the resulting evolution. The experimental results based on both synthetic and real images demonstrate that the proposed technique can solve a variety of challenging image segmentation problems. Futhermore, our method, which does not require any training, performs as good as methods based on training.

  12. Development of an unbiased statistical method for the analysis of unigenic evolution

    Directory of Open Access Journals (Sweden)

    Shilton Brian H

    2006-03-01

    Full Text Available Abstract Background Unigenic evolution is a powerful genetic strategy involving random mutagenesis of a single gene product to delineate functionally important domains of a protein. This method involves selection of variants of the protein which retain function, followed by statistical analysis comparing expected and observed mutation frequencies of each residue. Resultant mutability indices for each residue are averaged across a specified window of codons to identify hypomutable regions of the protein. As originally described, the effect of changes to the length of this averaging window was not fully eludicated. In addition, it was unclear when sufficient functional variants had been examined to conclude that residues conserved in all variants have important functional roles. Results We demonstrate that the length of averaging window dramatically affects identification of individual hypomutable regions and delineation of region boundaries. Accordingly, we devised a region-independent chi-square analysis that eliminates loss of information incurred during window averaging and removes the arbitrary assignment of window length. We also present a method to estimate the probability that conserved residues have not been mutated simply by chance. In addition, we describe an improved estimation of the expected mutation frequency. Conclusion Overall, these methods significantly extend the analysis of unigenic evolution data over existing methods to allow comprehensive, unbiased identification of domains and possibly even individual residues that are essential for protein function.

  13. The microstructure evolution of hydrogenated microcrystalline germanium promoted by power gradient method

    Science.gov (United States)

    Wang, Xinyu; Ni, Jian; Li, Chang; Sun, Xiaoxiang; Li, Zhenglong; Cai, Hongkun; Li, Juan; Zhang, Jianjun

    2016-12-01

    This paper studies the microstructure evolution of hydrogenated microcrystalline germanium (μc-Ge:H) thin films deposited by plasma enhanced chemical vapor deposition (PECVD). There is an amorphous incubation layer formed in the initial deposition stage of μc-Ge:H thin film. It is demonstrated that the thickness of incubation layer can be reduced by high hydrogen dilution and high discharge power method. However, at high hydrogen dilution, the deposition rate of μc-Ge:H appears a sharply decrease. Using a high discharge power can compensate the deposition rate decrease but lead to decrease of average grain size and appearance of micro-void in the μc-Ge:H thin film. In addition, by comparing two thickness groups of μc-Ge:H thin films deposited at different discharge powers, it is noticed that the evolution process relates to the formation of crystal nucleuses. Thus, a power gradient method is proposed to understand the mechanism of nucleation and crystal growth in the initial deposition process of μc-Ge:H films. Finally, by power gradient method, the incubation layer thickness of μc-Ge:H thin films has been decreased to less than 6 nm. Moreover, Raman scattering spectra shows a 38 nm μc-Ge:H film has a crystal fraction (XC) of 62.4%. Meanwhile, the mobility of TFT devices shows the improved electrical property of μc-Ge:H film deposited by power gradient method.

  14. Hybridization of Adaptive Differential Evolution with an Expensive Local Search Method

    Directory of Open Access Journals (Sweden)

    Rashida Adeeb Khanum

    2016-01-01

    Full Text Available Differential evolution (DE is an effective and efficient heuristic for global optimization problems. However, it faces difficulty in exploiting the local region around the approximate solution. To handle this issue, local search (LS techniques could be hybridized with DE to improve its local search capability. In this work, we hybridize an updated version of DE, adaptive differential evolution with optional external archive (JADE with an expensive LS method, Broydon-Fletcher-Goldfarb-Shano (BFGS for solving continuous unconstrained global optimization problems. The new hybrid algorithm is denoted by DEELS. To validate the performance of DEELS, we carried out extensive experiments on well known test problems suits, CEC2005 and CEC2010. The experimental results, in terms of function error values, success rate, and some other statistics, are compared with some of the state-of-the-art algorithms, self-adaptive control parameters in differential evolution (jDE, sequential DE enhanced by neighborhood search for large-scale global optimization (SDENS, and differential ant-stigmergy algorithm (DASA. These comparisons reveal that DEELS outperforms jDE and SDENS except DASA on the majority of test instances.

  15. Finite Volume Evolution Galerkin Methods for the Shallow Water Equations with Dry Beds

    OpenAIRE

    Bollermann, Andreas; Noelle, Sebastian; Medvidová, Maria Lukáčová -

    2015-01-01

    We present a new Finite Volume Evolution Galerkin (FVEG) scheme for the solution of the shallow water equations (SWE) with the bottom topography as a source term. Our new scheme will be based on the FVEG methods presented in (Luk\\'a\\v{c}ov\\'a, Noelle and Kraft, J. Comp. Phys. 221, 2007), but adds the possibility to handle dry boundaries. The most important aspect is to preserve the positivity of the water height. We present a general approach to ensure this for arbitrary finite volume schemes...

  16. Composite Differential Evolution with Modified Oracle Penalty Method for Constrained Optimization Problems

    Directory of Open Access Journals (Sweden)

    Minggang Dong

    2014-01-01

    Full Text Available Motivated by recent advancements in differential evolution and constraints handling methods, this paper presents a novel modified oracle penalty function-based composite differential evolution (MOCoDE for constrained optimization problems (COPs. More specifically, the original oracle penalty function approach is modified so as to satisfy the optimization criterion of COPs; then the modified oracle penalty function is incorporated in composite DE. Furthermore, in order to solve more complex COPs with discrete, integer, or binary variables, a discrete variable handling technique is introduced into MOCoDE to solve complex COPs with mix variables. This method is assessed on eleven constrained optimization benchmark functions and seven well-studied engineering problems in real life. Experimental results demonstrate that MOCoDE achieves competitive performance with respect to some other state-of-the-art approaches in constrained optimization evolutionary algorithms. Moreover, the strengths of the proposed method include few parameters and its ease of implementation, rendering it applicable to real life. Therefore, MOCoDE can be an efficient alternative to solving constrained optimization problems.

  17. Analytical methods for detecting pesticide switches with evolution of pesticide resistance.

    Science.gov (United States)

    Liang, Juhua; Tang, Sanyi; Nieto, Juan J; Cheke, Robert A

    2013-10-01

    After a pest develops resistance to a pesticide, switching between different unrelated pesticides is a common management option, but this raises the following questions: (1) What is the optimal frequency of pesticide use? (2) How do the frequencies of pesticide applications affect the evolution of pesticide resistance? (3) How can the time when the pest population reaches the economic injury level (EIL) be estimated and (4) how can the most efficient frequency of pesticide applications be determined? To address these questions, we have developed a novel pest population growth model incorporating the evolution of pesticide resistance and pulse spraying of pesticides. Moreover, three pesticide switching methods, threshold condition-guided, density-guided and EIL-guided, are modelled, to determine the best choice under different conditions with the overall aim of eradicating the pest or maintaining its population density below the EIL. Furthermore, the pest control outcomes based on those three pesticide switching methods are discussed. Our results suggest that either the density-guided or EIL-guided method is the optimal pesticide switching strategy, depending on the frequency (or period) of pesticide applications.

  18. Multiscale diffusion method for simulations of long-time defect evolution with application to dislocation climb

    Science.gov (United States)

    Baker, K. L.; Curtin, W. A.

    2016-07-01

    In many problems of interest to materials scientists and engineers, the evolution of crystalline extended defects (dislocations, cracks, grain boundaries, interfaces, voids, precipitates) is controlled by the flow of point defects (interstitial/substitutional atoms and/or vacancies) through the crystal into the extended defect. Precise modeling of this behavior requires fully atomistic methods in and around the extended defect, but the flow of point defects entering the defect region can be treated by coarse-grained methods. Here, a multiscale algorithm is presented to provide this coupling. Specifically, direct accelerated molecular dynamics (AMD) of extended defect evolution is coupled to a diffusing point defect concentration field that captures the long spatial and temporal scales of point defect motion in the presence of the internal stress fields generated by the evolving defect. The algorithm is applied to study vacancy absorption into an edge dislocation in aluminum where vacancy accumulation in the core leads to nucleation of a double-jog that then operates as a sink for additional vacancies; this corresponds to the initial stages of dislocation climb modeled with explicit atomistic resolution. The method is general and so can be applied to many other problems associated with nucleation, growth, and reaction due to accumulation of point defects in crystalline materials.

  19. Progress in Mechanism of Acute Arsine Poisoning and Urinary Arsenic Levels%急性砷化氢中毒机制与尿砷水平研究进展

    Institute of Scientific and Technical Information of China (English)

    韦光毅; 柳元; 陈启玲

    2009-01-01

    @@ 砷化氢(arsine,AsH3)是一种无色、略带大蒜味的溶血性剧毒性气体.AsH3与其他化合物不同,它既不是工业原料,也不是工业产品,而是某些生产过程中生成的废气.职业接触AsH3中毒多见于有色金属冶炼、后处理、深加工过程.另外,电解法生产硅铁、氰化法提取金银、无机或有机化合物水解等过程,也可生成AsH3[1].

  20. [Reasearch on evolution and transition of processing method of fuzi in ancient and modern times].

    Science.gov (United States)

    Liu, Chan-Chan; Cheng, Ming-En; Duan, Hai-Yan; Peng, Hua-Sheng

    2014-04-01

    Fuzi is a medicine used for rescuing from collapse by restoring yang as well as a famous toxic traditional Chinese medicine. In order to ensure the efficacy and safe medication, Fuzi has mostly been applied after being processed. There have been different Fuzi processing methods recorded by doctors of previous generations. Besides, there have also been differences in Fuzi processing methods recorded in modern pharmacopeia and ancient medical books. In this study, the authors traced back to medical books between the Han Dynasty and the period of Republic of China, and summarized Fuzi processing methods collected in ancient and modern literatures. According to the results, Fuzi processing methods and using methods have changed along with the evolution of dynasties, with differences in ancient and modern processing methods. Before the Tang Dynasty, Fuzi had been mostly processed and soaked. From Tang to Ming Dynasties, Fuzi had been mostly processed, soaked and stir-fried. During the Qing Dynasty, Fuzi had been mostly soaked and boiled. In the modem times, Fuzi is mostly processed by being boiled and soaked. Before the Tang Dynasty, a whole piece of Fuzi herbs or their fragments had been applied in medicines; Whereas their fragments are primarily used in the modern times. Because different processing methods have great impacts on the toxicity of Fuzi, it is suggested to study Fuzi processing methods.

  1. A method for calculating damage evolution in adiabatic shear band of titanium alloy

    Institute of Scientific and Technical Information of China (English)

    WANG Xue-bin

    2009-01-01

    A method for calculating the evolution of the local damage variable at the adiabatic shear band (ASB) center was proposed. In the present method, the JOHNSON-COOK model and the nonlocal theory were adopted, and the damage variable formula applicable for the bilinear (linearly elastic and strain-softening) constitutive relation was further generalized to consider the plastic deformation occurring in the strain-hardening stage. Aiming at Ti-6Al-4V, the effect of strain rate on the evolution of the local damage variable at the ASB center was investigated. In addition, a parametric study was carried out, including the effects of strain-hardening exponent, strain rate sensitive coefficient, thermal-softening exponent, static shear strength, strain-hardening modulus, shear elastic modulus, work to heat conversion factor, melting temperature and initial temperature. The damage extent at the ASB center in the radial collapse experiment was assessed. It is found that at higher strain rates the damage in the ASB becomes more serious at the same average plastic shear strain of the ASB.

  2. Incomplete Phase Space Reconstruction Method Based on Subspace Adaptive Evolution Approximation

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    Tai-fu Li

    2013-01-01

    Full Text Available The chaotic time series can be expanded to the multidimensional space by phase space reconstruction, in order to reconstruct the dynamic characteristics of the original system. It is difficult to obtain complete phase space for chaotic time series, as a result of the inconsistency of phase space reconstruction. This paper presents an idea of subspace approximation. The chaotic time series prediction based on the phase space reconstruction can be considered as the subspace approximation problem in different neighborhood at different time. The common static neural network approximation is suitable for a trained neighborhood, but it cannot ensure its generalization performance in other untrained neighborhood. The subspace approximation of neural network based on the nonlinear extended Kalman filtering (EKF is a dynamic evolution approximation from one neighborhood to another. Therefore, in view of incomplete phase space, due to the chaos phase space reconstruction, we put forward subspace adaptive evolution approximation method based on nonlinear Kalman filtering. This method is verified by multiple sets of wind speed prediction experiments in Wulong city, and the results demonstrate that it possesses higher chaotic prediction accuracy.

  3. Curve Evolution in Subspaces and Exploring the Metameric Class of Histogram of Gradient Orientation based Features using Nonlinear Projection Methods

    DEFF Research Database (Denmark)

    Tatu, Aditya Jayant

    defined subspace, the N-links bicycle chain space, i.e. the space of curves with equidistant neighboring landmark points. This in itself is a useful shape space for medical image analysis applications. The Histogram of Gradient orientation based features are many in number and are widely used......This thesis deals with two unrelated issues, restricting curve evolution to subspaces and computing image patches in the equivalence class of Histogram of Gradient orientation based features using nonlinear projection methods. Curve evolution is a well known method used in various applications like...... specific requirements like shape priors or a given data model, and due to limitations of the computer, the computed curve evolution forms a path in some finite dimensional subspace of the space of curves. We give methods to restrict the curve evolution to a finite dimensional linear or implicitly defined...

  4. New approach of (G′/G-expansion method and new approach of generalized (G′/G-expansion method for nonlinear evolution equation

    Directory of Open Access Journals (Sweden)

    Hasibun Naher

    2013-03-01

    Full Text Available In this article, new (G′/G-expansion method and new generalized (G′/G-expansion method is proposed to generate more general and abundant new exact traveling wave solutions of nonlinear evolution equations. The novelty and advantages of these methods is exemplified by its implementation to the KdV equation. The results emphasize the power of proposed methods in providing distinct solutions of different physical structures in nonlinear science. Moreover, these methods could be more effectively used to deal with higher dimensional and higher order nonlinear evolution equations which frequently arise in many scientific real time application fields.

  5. Semi-automated calibration method for modelling of mountain permafrost evolution in Switzerland

    Directory of Open Access Journals (Sweden)

    A. Marmy

    2015-09-01

    Full Text Available Permafrost is a widespread phenomenon in the European Alps. Many important topics such as the future evolution of permafrost related to climate change and the detection of permafrost related to potential natural hazards sites are of major concern to our society. Numerical permafrost models are the only tools which facilitate the projection of the future evolution of permafrost. Due to the complexity of the processes involved and the heterogeneity of Alpine terrain, models must be carefully calibrated and results should be compared with observations at the site (borehole scale. However, a large number of local point data are necessary to obtain a broad overview of the thermal evolution of mountain permafrost over a larger area, such as the Swiss Alps, and the site-specific model calibration of each point would be time-consuming. To face this issue, this paper presents a semi-automated calibration method using the Generalized Likelihood Uncertainty Estimation (GLUE as implemented in a 1-D soil model (CoupModel and applies it to six permafrost sites in the Swiss Alps prior to long-term permafrost evolution simulations. We show that this automated calibration method is able to accurately reproduce the main thermal condition characteristics with some limitations at sites with unique conditions such as 3-D air or water circulation, which have to be calibrated manually. The calibration obtained was used for RCM-based long-term simulations under the A1B climate scenario specifically downscaled at each borehole site. The projection shows general permafrost degradation with thawing at 10 m, even partially reaching 20 m depths until the end of the century, but with different timing among the sites. The degradation is more rapid at bedrock sites whereas ice-rich sites with a blocky surface cover showed a reduced sensitivity to climate change. The snow cover duration is expected to be reduced drastically (between −20 to −37 % impacting the ground thermal

  6. Modeling of the evolution of steppe chernozems and development of the method of pedogenetic chronology

    Science.gov (United States)

    Lisetskii, F. N.; Stolba, V. F.; Goleusov, P. V.

    2016-08-01

    Geoarchaeological methods were used to study chronosequences of surface soils in the steppe zone and to trace soil evolution during the Late Holocene in northwestern Crimea. It was found that the morphological and functional "maturity" of the humus horizons in steppe chernozems of the Late Holocene was reached in about 1600-1800 yrs. After this, their development decelerated irreversibly. The maximum concentration of trace elements accumulated in these horizons in the course of pedogenesis was reached in 1400 yrs. A new method of pedogenetic chronology based on the model chronofunction of the development of irreversible results of pedogenesis over time is suggested. Original pedochronological data and growth functions—the most suitable models for simulating pedogenesis over the past three thousand years—suggest that the development of morphological features of soil as an organomineral natural body follows growth patterns established for biological systems.

  7. On the modeling of bubble evolution and transport using coupled level-set/CFD method

    Energy Technology Data Exchange (ETDEWEB)

    Bartlomiej Wierzbicki; Steven P Antal; Michael Z Podowski [Dept. of Mechanical, Aerospace and Nuclear Engineering, and Center for Multiphase Research, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States)

    2005-07-01

    Full text of publication follows: The ability to predict the shape of the gas/liquid/solid interfaces is important for various multiphase flow and heat transfer applications. Specific issues of interest to nuclear reactor thermal-hydraulics, include the evolution of the shape of bubbles attached to solid surfaces during nucleation, bubble surface interactions in complex geometries, etc. Additional problems, making the overall task even more complicated, are associated with the effect of material properties that may be significantly altered by the addition of minute amounts of impurities, such as surfactants or nano-particles. The present paper is concerned with the development of an innovative approach to model time-dependent shape of gas/liquid interfaces in the presence of solid walls. The proposed approach combines a modified level-set method with an advanced CFD code, NPHASE. The coupled numerical solver can be used to simulate the evolution of gas/liquid interfaces in two-phase flows for a variety of geometries and flow conditions, from individual bubbles to free surfaces (stratified flows). The issues discussed in the full paper will include: a description of the novel aspects of the proposed level-set concept based method, an overview of the NPHASE code modeling framework and a description of the coupling method between these two elements of the overall model. A particular attention will be give to the consistency and completeness of model formulation for the interfacial phenomena near the liquid/gas/solid triple line, and to the impact of the proposed numerical approach on the accuracy and consistency of predictions. The accuracy will be measured in terms of both the calculated shape of the interfaces and the gas and liquid velocity fields around the interfaces and in the entire computational domain. The results of model testing and validation will also be shown in the full paper. The situations analyzed will include: bubbles of different sizes and varying

  8. A Model Parameter Extraction Method for Dielectric Barrier Discharge Ozone Chamber using Differential Evolution

    Science.gov (United States)

    Amjad, M.; Salam, Z.; Ishaque, K.

    2014-04-01

    In order to design an efficient resonant power supply for ozone gas generator, it is necessary to accurately determine the parameters of the ozone chamber. In the conventional method, the information from Lissajous plot is used to estimate the values of these parameters. However, the experimental setup for this purpose can only predict the parameters at one operating frequency and there is no guarantee that it results in the highest ozone gas yield. This paper proposes a new approach to determine the parameters using a search and optimization technique known as Differential Evolution (DE). The desired objective function of DE is set at the resonance condition and the chamber parameter values can be searched regardless of experimental constraints. The chamber parameters obtained from the DE technique are validated by experiment.

  9. Differential Evolution Based Intelligent System State Search Method for Composite Power System Reliability Evaluation

    Science.gov (United States)

    Bakkiyaraj, Ashok; Kumarappan, N.

    2015-09-01

    This paper presents a new approach for evaluating the reliability indices of a composite power system that adopts binary differential evolution (BDE) algorithm in the search mechanism to select the system states. These states also called dominant states, have large state probability and higher loss of load curtailment necessary to maintain real power balance. A chromosome of a BDE algorithm represents the system state. BDE is not applied for its traditional application of optimizing a non-linear objective function, but used as tool for exploring more number of dominant states by producing new chromosomes, mutant vectors and trail vectors based on the fitness function. The searched system states are used to evaluate annualized system and load point reliability indices. The proposed search methodology is applied to RBTS and IEEE-RTS test systems and results are compared with other approaches. This approach evaluates the indices similar to existing methods while analyzing less number of system states.

  10. Semi-automated calibration method for modelling of mountain permafrost evolution in Switzerland

    Science.gov (United States)

    Marmy, Antoine; Rajczak, Jan; Delaloye, Reynald; Hilbich, Christin; Hoelzle, Martin; Kotlarski, Sven; Lambiel, Christophe; Noetzli, Jeannette; Phillips, Marcia; Salzmann, Nadine; Staub, Benno; Hauck, Christian

    2016-11-01

    Permafrost is a widespread phenomenon in mountainous regions of the world such as the European Alps. Many important topics such as the future evolution of permafrost related to climate change and the detection of permafrost related to potential natural hazards sites are of major concern to our society. Numerical permafrost models are the only tools which allow for the projection of the future evolution of permafrost. Due to the complexity of the processes involved and the heterogeneity of Alpine terrain, models must be carefully calibrated, and results should be compared with observations at the site (borehole) scale. However, for large-scale applications, a site-specific model calibration for a multitude of grid points would be very time-consuming. To tackle this issue, this study presents a semi-automated calibration method using the Generalized Likelihood Uncertainty Estimation (GLUE) as implemented in a 1-D soil model (CoupModel) and applies it to six permafrost sites in the Swiss Alps. We show that this semi-automated calibration method is able to accurately reproduce the main thermal condition characteristics with some limitations at sites with unique conditions such as 3-D air or water circulation, which have to be calibrated manually. The calibration obtained was used for global and regional climate model (GCM/RCM)-based long-term climate projections under the A1B climate scenario (EU-ENSEMBLES project) specifically downscaled at each borehole site. The projection shows general permafrost degradation with thawing at 10 m, even partially reaching 20 m depth by the end of the century, but with different timing among the sites and with partly considerable uncertainties due to the spread of the applied climatic forcing.

  11. Cyndi: a multi-objective evolution algorithm based method for bioactive molecular conformational generation

    Directory of Open Access Journals (Sweden)

    Li Honglin

    2009-03-01

    Full Text Available Abstract Background Conformation generation is a ubiquitous problem in molecule modelling. Many applications require sampling the broad molecular conformational space or perceiving the bioactive conformers to ensure success. Numerous in silico methods have been proposed in an attempt to resolve the problem, ranging from deterministic to non-deterministic and systemic to stochastic ones. In this work, we described an efficient conformation sampling method named Cyndi, which is based on multi-objective evolution algorithm. Results The conformational perturbation is subjected to evolutionary operation on the genome encoded with dihedral torsions. Various objectives are designated to render the generated Pareto optimal conformers to be energy-favoured as well as evenly scattered across the conformational space. An optional objective concerning the degree of molecular extension is added to achieve geometrically extended or compact conformations which have been observed to impact the molecular bioactivity (J Comput -Aided Mol Des 2002, 16: 105–112. Testing the performance of Cyndi against a test set consisting of 329 small molecules reveals an average minimum RMSD of 0.864 Å to corresponding bioactive conformations, indicating Cyndi is highly competitive against other conformation generation methods. Meanwhile, the high-speed performance (0.49 ± 0.18 seconds per molecule renders Cyndi to be a practical toolkit for conformational database preparation and facilitates subsequent pharmacophore mapping or rigid docking. The copy of precompiled executable of Cyndi and the test set molecules in mol2 format are accessible in Additional file 1. Conclusion On the basis of MOEA algorithm, we present a new, highly efficient conformation generation method, Cyndi, and report the results of validation and performance studies comparing with other four methods. The results reveal that Cyndi is capable of generating geometrically diverse conformers and outperforms

  12. Modelling of the evolutional methods to satisfy the consumer’s needs in new product development

    Directory of Open Access Journals (Sweden)

    L.K. Hlinenko

    2014-09-01

    Full Text Available The aim of the article. The aim of the article is development of evolutional models of methods and means of satisfying the consumer needs in a form of corresponding lines of development represented by sets of successive discrete states regularly passed by these methods and means in the process of evolution. Such models are supposed to match demands of the NPD process providing objective appraisal and predicting of the consumer value of innovation taking into account the change of consumer needs of and attitude toward the methods of satisfying them under global market changes and consumer trends that these changes reflect. The results of the analysis. New product correspondence with customer needs is one of the critical terms of their market success. Existing methods of estimation of this correspondence make it possible to estimate only “obvious” needs and demands in the moment or during the period of interaction with the consumer while latent and future needs remain beyond the investigation. Consumers are not static in their needs and behaviour, their demands to level and means of satisfaction of needs change under the influence of volatile environment and as a result of consumer self-development. Collected and proceeded by traditional marketing research technologies data does not provide in-depth and reliable understanding even of present state of consumer needs structure because of difficulties of synchronization and integration of varied consumer inputs and fuzziness of consumer segments; a problem of future needs identification for successful new product development is still left in abeyance. Satisfaction of any need evolves in direction of “idealization” i.e. satisfying in a moment and place of emergence of the need free of charge on the process of satisfying. The idealization trend is realized through: 1 dynamization, integration and specialization of needs; 2 increase of level of satisfaction of every need and number of

  13. EVolution: an edge-based variational method for non-rigid multi-modal image registration

    Science.gov (United States)

    de Senneville, B. Denis; Zachiu, C.; Ries, M.; Moonen, C.

    2016-10-01

    Image registration is part of a large variety of medical applications including diagnosis, monitoring disease progression and/or treatment effectiveness and, more recently, therapy guidance. Such applications usually involve several imaging modalities such as ultrasound, computed tomography, positron emission tomography, x-ray or magnetic resonance imaging, either separately or combined. In the current work, we propose a non-rigid multi-modal registration method (namely EVolution: an edge-based variational method for non-rigid multi-modal image registration) that aims at maximizing edge alignment between the images being registered. The proposed algorithm requires only contrasts between physiological tissues, preferably present in both image modalities, and assumes deformable/elastic tissues. Given both is shown to be well suitable for non-rigid co-registration across different image types/contrasts (T1/T2) as well as different modalities (CT/MRI). This is achieved using a variational scheme that provides a fast algorithm with a low number of control parameters. Results obtained on an annotated CT data set were comparable to the ones provided by state-of-the-art multi-modal image registration algorithms, for all tested experimental conditions (image pre-filtering, image intensity variation, noise perturbation). Moreover, we demonstrate that, compared to existing approaches, our method possesses increased robustness to transient structures (i.e. that are only present in some of the images).

  14. A software for parameter optimization with Differential Evolution Entirely Parallel method

    Directory of Open Access Journals (Sweden)

    Konstantin Kozlov

    2016-08-01

    Full Text Available Summary. Differential Evolution Entirely Parallel (DEEP package is a software for finding unknown real and integer parameters in dynamical models of biological processes by minimizing one or even several objective functions that measure the deviation of model solution from data. Numerical solutions provided by the most efficient global optimization methods are often problem-specific and cannot be easily adapted to other tasks. In contrast, DEEP allows a user to describe both mathematical model and objective function in any programming language, such as R, Octave or Python and others. Being implemented in C, DEEP demonstrates as good performance as the top three methods from CEC-2014 (Competition on evolutionary computation benchmark and was successfully applied to several biological problems. Availability. DEEP method is an open source and free software distributed under the terms of GPL licence version 3. The sources are available at http://deepmethod.sourceforge.net/ and binary packages for Fedora GNU/Linux are provided for RPM package manager at https://build.opensuse.org/project/repositories/home:mackoel:compbio.

  15. A simple and general method for solving detailed chemical evolution with delayed production of iron and other chemical elements

    CERN Document Server

    Vincenzo, Fiorenzo; Spitoni, Emanuele

    2016-01-01

    In this Letter, we present a new theoretical method for solving the chemical evolution of galaxies, by assuming the instantaneous recycling approximation for chemical elements restored by massive stars and the Delay Time Distribution formalism for the delayed chemical enrichment by Type Ia Supernovae. The galaxy gas mass assembly history, together with the assumed stellar yields and initial mass function, represent the starting point of this method. We derive a very simple and general equation which closely relates the Laplace transforms of the galaxy gas accretion and star formation history, which can be used to simplify the problem of retrieving these quantities in most of current galaxy evolution models. We find that - once the galaxy star formation history has been reconstructed from our assumptions - the differential equation for the evolution of the chemical element $X$ can be suitably solved with classical methods. We apply our model to reproduce the $[\\text{O/Fe}]$ and $[\\text{Si/Fe}]$ vs. $[\\text{Fe/...

  16. Predicting the Evolution of CO2 Emissions in Bahrain with Automated Forecasting Methods

    Directory of Open Access Journals (Sweden)

    Cristiana Tudor

    2016-09-01

    Full Text Available The 2012 Doha meeting established the continuation of the Kyoto protocol, the legally-binding global agreement under which signatory countries had agreed to reduce their carbon emissions. Contrary to this assumed obligation, all G20 countries with the exception of France and the UK saw significant increases in their CO2 emissions over the last 25 years, surpassing 300% in the case of China. This paper attempts to forecast the evolution of carbon dioxide emissions in Bahrain over the 2012–2021 decade by employing seven Automated Forecasting Methods, including the exponential smoothing state space model (ETS, the Holt–Winters Model, the BATS/TBATS model, ARIMA, the structural time series model (STS, the naive model, and the neural network time series forecasting method (NNAR. Results indicate a reversal of the current decreasing trend of pollution in the country, with a point estimate of 2309 metric tons per capita at the end of 2020 and 2317 at the end of 2021, as compared to the 1934 level achieved in 2010. The country’s baseline level corresponding to year 1990 (as specified by the Doha amendment of the Kyoto protocol is approximately 25.54 metric tons per capita, which implies a maximum level of 20.96 metric tons per capita for the year 2020 (corresponding to a decrease of 18% relative to the baseline level in order for Bahrain to comply with the protocol. Our results therefore suggest that Bahrain cannot meet its assumed target.

  17. Landscapes of human evolution: models and methods of tectonic geomorphology and the reconstruction of hominin landscapes.

    Science.gov (United States)

    Bailey, Geoffrey N; Reynolds, Sally C; King, Geoffrey C P

    2011-03-01

    This paper examines the relationship between complex and tectonically active landscapes and patterns of human evolution. We show how active tectonics can produce dynamic landscapes with geomorphological and topographic features that may be critical to long-term patterns of hominin land use, but which are not typically addressed in landscape reconstructions based on existing geological and paleoenvironmental principles. We describe methods of representing topography at a range of scales using measures of roughness based on digital elevation data, and combine the resulting maps with satellite imagery and ground observations to reconstruct features of the wider landscape as they existed at the time of hominin occupation and activity. We apply these methods to sites in South Africa, where relatively stable topography facilitates reconstruction. We demonstrate the presence of previously unrecognized tectonic effects and their implications for the interpretation of hominin habitats and land use. In parts of the East African Rift, reconstruction is more difficult because of dramatic changes since the time of hominin occupation, while fossils are often found in places where activity has now almost ceased. However, we show that original, dynamic landscape features can be assessed by analogy with parts of the Rift that are currently active and indicate how this approach can complement other sources of information to add new insights and pose new questions for future investigation of hominin land use and habitats.

  18. Tracking evolution of myoglobin stability in cetaceans using experimentally calibrated computational methods that account for generic protein relaxation.

    Science.gov (United States)

    Holm, Jeppe; Dasmeh, Pouria; Kepp, Kasper P

    2016-07-01

    The evolution of cetaceans (whales, dolphins, and porpoises) from land to water is one of the most spectacular events in mammal evolution. It has been suggested that selection for higher myoglobin stability (∆G of folding) allowed whales to conquer the deep-diving niche. The stability of multi-site protein variants, including ancient proteins, is however hard to describe theoretically. From a compilation of experimental ∆∆G vs. ∆G we first find that protein substitutions are subject to large generic protein relaxation effects. Using this discovery, we develop a simple two-parameter model that predicts multi-site ∆∆G as accurately as standard methods do for single-site mutations and reproduces trends in contemporary myoglobin stabilities. We then apply this new method to the study of the evolution of Mb stability in cetaceans: With both methods the main change in stability (about 1kcal/mol) occurred very early, and stability was later relaxed in dolphins and porpoises, but was further increased in the sperm whales. This suggests that single proteins can affect whole organism evolution and indicates a role of Mb stability in the evolution of cetaceans. Transition to the deep-diving niche probably occurred already in the ancestor of contemporary baleen and toothed whales. In summary, we have discovered generic stability relaxation effects in proteins that, when incorporated into a simple model, improves the description of multi-site protein variants.

  19. Controlling population evolution in the laboratory to evaluate methods of historical inference.

    Directory of Open Access Journals (Sweden)

    Patrick Mardulyn

    Full Text Available Natural populations of known detailed past demographic history are extremely valuable to evaluate methods of historical inference, yet are extremely rare. As an alternative approach, we have generated multiple replicate microsatellite data sets from laboratory-cultured populations of a gonochoric free-living nematode, Caenorhabditis remanei, that were constrained to pre-defined demographic histories featuring different levels of migration among populations or bottleneck events of different magnitudes. These data sets were then used to evaluate the performances of two recently developed population genetics methods, BayesAss+, that estimates recent migration rates among populations, and Bottleneck, that detects the occurrence of recent bottlenecks. Migration rates inferred by BayesAss+ were generally over-estimates, although these were often included within the confidence interval. Analyses of data sets simulated in-silico, using a model mimicking the laboratory experiments, produced less biased estimates of the migration rates, and showed increased efficiency of the program when the number of loci and sampled genotypes per population was higher. In the replicates for which the pre-bottleneck laboratory-cultured populations did not significantly depart from a mutation/drift equilibrium, an important assumption of the program Bottleneck, only a portion of the bottleneck events were detected. This result was confirmed by in-silico simulations mirroring the laboratory bottleneck experiments. More generally, our study demonstrates the feasibility, and highlights some of the limits, of the approach that consists in generating molecular genetic data sets by controlling the evolution of laboratory-reared nematode populations, for the purpose of validating methods inferring population history.

  20. A method for evaluating the evolution of clogging: application to the Pampulha Campus infiltration system (Brazil).

    Science.gov (United States)

    Barraud, S; Gonzalez-Merchan, C; Nascimento, N; Moura, P; Silva, A

    2014-01-01

    In order to evaluate the hydraulic performance of stormwater infiltration trenches, a study was undertaken to assess clogging and its distribution between the bottom and the sides. The method used was based on the calibration of the hydraulic resistance event by event according to Bouwer's model and applied to a demonstration trench in Belo-Horizonte monitored in the framework of the European Project Switch. The calibration was performed by minimizing the distance between measured and modeled infiltration flow rates and by using continuous measurements of rainfall, inflow, water temperature and depth in the trench. The study showed that the methodology and particularly Bouwer's model was able to produce satisfactory results. It revealed a significant clogging evolution within a year, with global resistance increasing by a factor of 9. A significant difference between the bottom and the sides was observed; the bottom being more rapidly prone to clogging. Sudden fluctuations of the hydraulic resistance of the bottom were found that could be explained by very high concentrations of total suspended solids from inflows (about 2,000 mg/L). Clogging of the sides evolves over the time but with a very low rate.

  1. Phase-Field Methods for Structure Evolution in Sheared Multiphase Systems

    Science.gov (United States)

    Badalassi, Vittorio; Ceniceros, Hector; Banerjee, Sanjoy

    2002-01-01

    A homogeneous disordered phase separates into ordered structures when quenched into a broken-symmetry phase. The competition of broken-symmetry phases to select an equilibrium state may be studied in terms of coarse-grained order parameters described by a suitable Landau free-energy function. A network of equilibrium-phase domains develops on quenching and coarsens with time with a topology that may be controlled by shear. We use three-dimensional simulations, in which time-dependent models for conserved-order parameters coupled to Navier-Stokes fluid models are solved, to investigate the evolution of such domains, e.g. spinodal decompositions of polymeric materials under shear. The numerical problems are formidable because of the strong nonlinearities inherent in the coupled model, and these are amongst the first 3D calculations undertaken. In linear shear fields we find stable nanostrings, also recently seen in experiments. The affinity of the ordered phases to boundaries plays a role in the form of the structures that develop, with stacked plate-like phase distributions emerging under certain conditions. Such methods appear quite promising for design and analysis of multiphase and complex fluid formulations. The behavior of foams in such conditions is of particular interest in microgravity environments. Additional information can be found in the original extended abstract.

  2. Advancing Reactive Tracer Methods for Measurement of Thermal Evolution in Geothermal Reservoirs: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell A. Plummer; Carl D. Palmer; Earl D. Mattson; Laurence C. Hull; George D. Redden

    2011-07-01

    The injection of cold fluids into engineered geothermal system (EGS) and conventional geothermal reservoirs may be done to help extract heat from the subsurface or to maintain pressures within the reservoir (e.g., Rose et al., 2001). As these injected fluids move along fractures, they acquire heat from the rock matrix and remove it from the reservoir as they are extracted to the surface. A consequence of such injection is the migration of a cold-fluid front through the reservoir (Figure 1) that could eventually reach the production well and result in the lowering of the temperature of the produced fluids (thermal breakthrough). Efficient operation of an EGS as well as conventional geothermal systems involving cold-fluid injection requires accurate and timely information about thermal depletion of the reservoir in response to operation. In particular, accurate predictions of the time to thermal breakthrough and subsequent rate of thermal drawdown are necessary for reservoir management, design of fracture stimulation and well drilling programs, and forecasting of economic return. A potential method for estimating migration of a cold front between an injection well and a production well is through application of reactive tracer tests, using chemical whose rate of degradation is dependent on the reservoir temperature between the two wells (e.g., Robinson 1985). With repeated tests, the rate of migration of the thermal front can be determined, and the time to thermal breakthrough calculated. While the basic theory behind the concept of thermal tracers has been understood for some time, effective application of the method has yet to be demonstrated. This report describes results of a study that used several methods to investigate application of reactive tracers to monitoring the thermal evolution of a geothermal reservoir. These methods included (1) mathematical investigation of the sensitivity of known and hypothetical reactive tracers, (2) laboratory testing of novel

  3. Third order finite volume evolution Galerkin (FVEG) methods for two-dimensional wave equation system

    OpenAIRE

    Lukácová-Medvid'ová, Maria; Warnecke, Gerald; Zahaykah, Yousef

    2003-01-01

    The subject of the paper is the derivation and analysis of third order finite volume evolution Galerkin schemes for the two-dimensional wave equation system. To achieve this the first order approximate evolution operator is considered. A recovery stage is carried out at each level to generate a piecewise polynomial approximation from the piecewise constants, to feed into the calculation of the fluxes. We estimate the truncation error and give numerical examples to demonstrate the higher order...

  4. Lie transformation method on quantum state evolution of a general time-dependent driven and damped parametric oscillator

    Science.gov (United States)

    Zhang, Lin; Zhang, Weiping

    2016-10-01

    A variety of dynamics in nature and society can be approximately treated as a driven and damped parametric oscillator. An intensive investigation of this time-dependent model from an algebraic point of view provides a consistent method to resolve the classical dynamics and the quantum evolution in order to understand the time-dependent phenomena that occur not only in the macroscopic classical scale for the synchronized behaviors but also in the microscopic quantum scale for a coherent state evolution. By using a Floquet U-transformation on a general time-dependent quadratic Hamiltonian, we exactly solve the dynamic behaviors of a driven and damped parametric oscillator to obtain the optimal solutions by means of invariant parameters of Ks to combine with Lewis-Riesenfeld invariant method. This approach can discriminate the external dynamics from the internal evolution of a wave packet by producing independent parametric equations that dramatically facilitate the parametric control on the quantum state evolution in a dissipative system. In order to show the advantages of this method, several time-dependent models proposed in the quantum control field are analyzed in detail.

  5. Evolution of regional to global paddy rice mapping methods: A review

    Science.gov (United States)

    Dong, Jinwei; Xiao, Xiangming

    2016-09-01

    Paddy rice agriculture plays an important role in various environmental issues including food security, water use, climate change, and disease transmission. However, regional and global paddy rice maps are surprisingly scarce and sporadic despite numerous efforts in paddy rice mapping algorithms and applications. With the increasing need for regional to global paddy rice maps, this paper reviewed the existing paddy rice mapping methods from the literatures ranging from the 1980s to 2015. In particular, we illustrated the evolution of these paddy rice mapping efforts, looking specifically at the future trajectory of paddy rice mapping methodologies. The biophysical features and growth phases of paddy rice were analyzed first, and feature selections for paddy rice mapping were analyzed from spectral, polarimetric, temporal, spatial, and textural aspects. We sorted out paddy rice mapping algorithms into four categories: (1) Reflectance data and image statistic-based approaches, (2) vegetation index (VI) data and enhanced image statistic-based approaches, (3) VI or RADAR backscatter-based temporal analysis approaches, and (4) phenology-based approaches through remote sensing recognition of key growth phases. The phenology-based approaches using unique features of paddy rice (e.g., transplanting) for mapping have been increasingly used in paddy rice mapping. Current applications of these phenology-based approaches generally use coarse resolution MODIS data, which involves mixed pixel issues in Asia where smallholders comprise the majority of paddy rice agriculture. The free release of Landsat archive data and the launch of Landsat 8 and Sentinel-2 are providing unprecedented opportunities to map paddy rice in fragmented landscapes with higher spatial resolution. Based on the literature review, we discussed a series of issues for large scale operational paddy rice mapping.

  6. Influence of processing methods on residual stress evolution in coated conductors

    Science.gov (United States)

    Cheon, J. H.; Shankar, P. S.; Singh, J. P.

    2005-01-01

    Several processing methods are under study for deposition of different layers of YBa2Cu3O7-x- (YBCO-) coated conductors. The effect of these processing techniques on residual stress evolution in thin films of yttria-stabilized zirconia (YSZ) and YBCO was evaluated by measurement of the residual stresses using x-ray diffraction (XRD). The YSZ films (textured and nontextured) were deposited on Hastelloy C substrates by ion-beam-assisted deposition (IBAD), and the YBCO films were deposited on lanthanum aluminate (LaAlO3) substrates by pulsed laser deposition (PLD) and sol-gel techniques. The measured residual stresses in the YSZ films (both textured and nontextured) were more compressive than the calculated thermal mismatch stress between Hastelloy C and YSZ, apparently due to intrinsic compressive stresses induced in the YSZ films during IBAD processing. In addition, a lower compressive residual stress was measured in the textured YSZ film compared to the nontextured film because of a reduction in the intrinsic compressive stress in the textured film. PLD processing of YBCO films on LaAlO3 substrate resulted in a lower tensile residual stress (in the YBCO film) than the calculated thermal mismatch stress between YBCO and LaAlO3. This difference is attributed to the generation of intrinsic compressive stresses in the YBCO film during PLD, in a manner similar to IBAD. In comparison to IBAD and PLD, sol-gel processing apparently generated negligible intrinsic stresses, resulting in a good agreement between the measured residual stress in the YBCO film and the calculated thermal mismatch stress between YBCO and LaAlO3.

  7. Method of Multiple Scales and Travelling Wave Solutions for (2+1)-Dimensional KdV Type Nonlinear Evolution Equations

    Science.gov (United States)

    Ayhan, Burcu; Özer, M. Naci; Bekir, Ahmet

    2016-08-01

    In this article, we applied the method of multiple scales for Korteweg-de Vries (KdV) type equations and we derived nonlinear Schrödinger (NLS) type equations. So we get a relation between KdV type equations and NLS type equations. In addition, exact solutions were found for KdV type equations. The ( G'} over G )-expansion methods and the ( {G'} over G, {1 over G}} )-expansion methods were proposed to establish new exact solutions for KdV type differential equations. We obtained periodic and hyperbolic function solutions for these equations. These methods are very effective for getting travelling wave solutions of nonlinear evolution equations (NEEs).

  8. A note on improved F-expansion method combined with Riccati equation applied to nonlinear evolution equations.

    Science.gov (United States)

    Islam, Md Shafiqul; Khan, Kamruzzaman; Akbar, M Ali; Mastroberardino, Antonio

    2014-10-01

    The purpose of this article is to present an analytical method, namely the improved F-expansion method combined with the Riccati equation, for finding exact solutions of nonlinear evolution equations. The present method is capable of calculating all branches of solutions simultaneously, even if multiple solutions are very close and thus difficult to distinguish with numerical techniques. To verify the computational efficiency, we consider the modified Benjamin-Bona-Mahony equation and the modified Korteweg-de Vries equation. Our results reveal that the method is a very effective and straightforward way of formulating the exact travelling wave solutions of nonlinear wave equations arising in mathematical physics and engineering.

  9. An extended functional transformation method and its application in some evolution equations

    Institute of Scientific and Technical Information of China (English)

    Ding Hai-Yong; Xu Xi-Xiang; Yang Hong-Xiang

    2005-01-01

    In this paper, an extended functional transformation is given to solve some nonlinear evolution equations. This function, in fact, is a solution of the famous KdV equation, so this transformation gives a transformation between KdV equation and other soliton equations. Then many new exact solutions can be given by virtue of the solutions of KdV equation.

  10. Evolution of Humans: Understanding the Nature and Methods of Science through Cooperative Learning

    Science.gov (United States)

    Lee, Yeung Chung

    2011-01-01

    This article describes the use of an enquiry-based approach to the study of human evolution in a practical context, integrating role-playing, jigsaw cooperative learning and scientific argumentation. The activity seeks to unravel the evolutionary relationships of five hominids and one ape from rather "messy" evidence. This approach enhanced the…

  11. Evolution operator equation: Integration with algebraic and finite difference methods. Applications to physical problems in classical and quantum mechanics and quantum field theory

    Energy Technology Data Exchange (ETDEWEB)

    Dattoli, Giuseppe; Torre, Amalia [ENEA, Centro Ricerche Frascati, Rome (Italy). Dipt. Innovazione; Ottaviani, Pier Luigi [ENEA, Centro Ricerche Bologna (Italy); Vasquez, Luis [Madris, Univ. Complutense (Spain). Dept. de Matemateca Aplicado

    1997-10-01

    The finite-difference based integration method for evolution-line equations is discussed in detail and framed within the general context of the evolution operator picture. Exact analytical methods are described to solve evolution-like equations in a quite general physical context. The numerical technique based on the factorization formulae of exponential operator is then illustrated and applied to the evolution-operator in both classical and quantum framework. Finally, the general view to the finite differencing schemes is provided, displaying the wide range of applications from the classical Newton equation of motion to the quantum field theory.

  12. Structural evolution of LC4 alloy in making thixotropic billet by SIMA method

    Institute of Scientific and Technical Information of China (English)

    罗守靖; 田文彤; 张广安

    2001-01-01

    The effect of SIMA process parameters on LC4 alloy's microstructure and the microstructural evolution of various soaking times have been studied. The results show that effective strain in cold deformation before reheating has a great influence on microstructural evolution. Grain size decreases and its shape also approaches to sphericity with increasing effective strain. The amount of liquid phase increases at grain boundaries and grain shape becomes smooth with increasing heating temperature. The main mechanism of grain coarsening is coalescence when eutectic liquid is rare and not totally distributed at all boundaries. Otherwise the main mechanism of grain coarsening is Ostwald ripening and the connection coarsening is more difficult to perform when the regions are nearly full of eutectic liquid.

  13. Analytical methods for detecting pesticide switches with evolution of pesticide resistance

    OpenAIRE

    Liang, Juhua; Tang, Sanyi; Juan J. Nieto; Cheke, Robert A.

    2013-01-01

    After a pest develops resistance to a pesticide, switching between different unrelated pesticides is a common management option, but this raises the following questions: (1) What is the optimal frequency of pesticide use? (2) How do the frequencies of pesticide applications affect the evolution of pesticide resistance? (3) How can the time when the pest population reaches the economic injury level (EIL) be estimated and (4) how can the most efficient frequency of pesticide applications be dete...

  14. New type of exact solutions of nonlinear evolution equations via the new Sine-Poisson equation expansion method

    Energy Technology Data Exchange (ETDEWEB)

    Yao Yuqin [College of Sciences, Shanghai University, Shanghai 200436 (China)] e-mail: yyqinw@126.com

    2005-11-01

    In this paper, based on the well-known Sine-Poisson equation, a new Sine-Poisson equation expansion method with constant coefficients or variable coefficients is presented, which can be used to construct more new exact solutions of nonlinear evolution equations in mathematical physics. The KdV-mKdV equation and the typical breaking soliton equation are chosen to illustrate our method such that many types of new exact solutions are obtained, which include exponential solutions, kink-shaped solutions, singular solutions and soliton-like solutions.

  15. A Method for Measuring Fast Time Evolutions of the Plasma Potential by Means of a Simple Emissive Probe

    DEFF Research Database (Denmark)

    Iizuka, S.; Michelsen, Poul; Juul Rasmussen, Jens;

    1981-01-01

    A method is presented for obtaining the temporal evolution of the plasma potential, which is assumed to be given by the floating potential of a simple emissive probe. The construction of the probe is also described. The method avoids the slow time response of the usual technique where the floating...... potential is measured across a high resistance. During each sweep of the probe voltage, the changing of the sign of the probe current, which is sampled at a specific time, gives rise to a negative pulse, driving the pen-lift of an X-Y recorder. Since the real floating potential is measured where the probe...

  16. Analysis and Trend Determination of the Evolution of Tourist Accommodation Establishments (Adjusted Data Based Seasonally in the European Union (28 with Analytical Methods

    Directory of Open Access Journals (Sweden)

    Rodica Pripoaie

    2015-05-01

    Full Text Available This work presents the comparative analysis and trend determination of the evolution tourist accommodation establishments in the European Union (28, adjusted data based seasonally, in the period May 2014 - December 2014 used the Analytical Methods. The principal causes of the evolution tourist accommodation establishments were: the general economic evolution of industries and GDP per capita, the relatively low revenue or low development of the infrastructure. Trend determination of the evolution tourist accommodation establishments in the European Union (28 with analytical methods requires least squares method. On the base the results of the absolute deviations between empirical and theoretical values for the linear, curvilinear and modified exponential regression, will choose the best trend equation for the smallest variation. The best trend model for evolution tourist accommodation establishments in EU (28 is modelled using linear regression equation.

  17. Numerical evolutions of fields on the 2-sphere using a spectral method based on spin-weighted spherical harmonics

    CERN Document Server

    Beyer, Florian; Frauendiener, Jörg; Whale, Ben

    2013-01-01

    Many applications in science call for the numerical simulation of systems on manifolds with spherical topology. Through use of integer spin weighted spherical harmonics we present a method which allows for the implementation of arbitrary tensorial evolution equations. Our method combines two numerical techniques that were originally developed with different applications in mind. The first is Huffenberger and Wandelt's spectral decomposition algorithm to perform the mapping from physical to spectral space. The second is the application of Luscombe and Luban's method, to convert numerically divergent linear recursions into stable nonlinear recursions, to the calculation of reduced Wigner d-functions. We give a detailed discussion of the theory and numerical implementation of our algorithm. The properties of our method are investigated by solving the scalar and vectorial advection equation on the sphere, as well as the 2+1 Maxwell equations on a deformed sphere.

  18. The Parallel Asynchronous Differential Evolution Method as a Tool to Analyze Synchrotron Scattering Experimental Data from Vesicular Systems

    Science.gov (United States)

    Zhabitskaya, Evgeniya; Zemlyanaya, Elena; Kiselev, Mikhail; Gruzinov, Andrey

    2016-02-01

    In this work we use an Asynchronous Differential Evolution (ADE) method to estimate parameters of the Separated Form Factor (SFF) model which is used to investigate a structure of drug delivery Phospholipid Transport Nano System (PTNS) unilamellar vesicles by experimental small angle synchrotron X-ray scattering spectra (SAXS). We compare the efficiency of different optimizing procedures (OP) for the search for the SFF-model parameters. It is shown that the probability to find the global solution of this problem by ADE-methods is significantly higher than that by either Nelder-Mead method or a Quasi-Newton method with Davidon-Fletcher-Powell formula. The parallel realization of ADE accelerates the calculations significantly. The speed-up obtained by the parallel realization of ADE and results of the model are presented. The work has been performed under the grant of Russian Scientific Foundation (project No 14-12-00516)

  19. The Parallel Asynchronous Differential Evolution Method as a Tool to Analyze Synchrotron Scattering Experimental Data from Vesicular Systems*

    Directory of Open Access Journals (Sweden)

    Zhabitskaya Evgeniya

    2016-01-01

    Full Text Available In this work we use an Asynchronous Differential Evolution (ADE method to estimate parameters of the Separated Form Factor (SFF model which is used to investigate a structure of drug delivery Phospholipid Transport Nano System (PTNS unilamellar vesicles by experimental small angle synchrotron X-ray scattering spectra (SAXS. We compare the efficiency of different optimizing procedures (OP for the search for the SFF-model parameters. It is shown that the probability to find the global solution of this problem by ADE-methods is significantly higher than that by either Nelder-Mead method or a Quasi-Newton method with Davidon-Fletcher-Powell formula. The parallel realization of ADE accelerates the calculations significantly. The speed-up obtained by the parallel realization of ADE and results of the model are presented.

  20. Determination of Ar Concentration Evolution Within DIII-D Core Plasma by X-ray Ross Filter Method

    Science.gov (United States)

    Bogatu, I. N.; Edgell, D. H.; Brooks, N. H.; Snider, R. T.; West, W. P.; Wade, M. R.

    2001-10-01

    Injection of the non-recycling noble gas Ar into the DIII-D divertor is a promising technique for reducing the heat load on the plates; it also seems to improve thermal transport in an advanced operating mode. During such experiments core plasma contamination by migrating Ar can be investigated by measuring the evolution of the Ar concentration profile using the Ross filter method implemented on the fan shaped X-ray poloidal diagnostics on DIII-D. A Ross filter with energy pass band centered on the ArXVII K_α line at 3.14 keV, discriminating Ar K_α line against background radiation, was used on DIII-D. A high sensitivity to the injected quantity of Ar and good discrimination against Ne was observed. We present reconstruction of Ar concentration profiles from the chord-integrated measurements using the measured Te and ne profiles. Using the transport code MIST, the impurity diffusion coefficients can be determined by matching the time evolution of the Ar concentration evolution.

  1. Coda Wave Interferometry Method Applied in Structural Monitoring to Assess Damage Evolution in Masonry and Concrete Structures

    Science.gov (United States)

    Masera, D.; Bocca, P.; Grazzini, A.

    2011-07-01

    In this experimental program the main goal is to monitor the damage evolution in masonry and concrete structures by Acoustic Emission (AE) signal analysis applying a well-know seismic method. For this reason the concept of the coda wave interferometry is applied to AE signal recorded during the tests. Acoustic Emission (AE) are very effective non-destructive techniques applied to identify micro and macro-defects and their temporal evolution in several materials. This technique permits to estimate the velocity of ultrasound waves propagation and the amount of energy released during fracture propagation to obtain information on the criticality of the ongoing process. By means of AE monitoring, an experimental analysis on a set of reinforced masonry walls under variable amplitude loading and strengthening reinforced concrete (RC) beams under monotonic static load has been carried out. In the reinforced masonry wall, cyclic fatigue stress has been applied to accelerate the static creep and to forecast the corresponding creep behaviour of masonry under static long-time loading. During the tests, the evaluation of fracture growth is monitored by coda wave interferometry which represents a novel approach in structural monitoring based on AE relative change velocity of coda signal. In general, the sensitivity of coda waves has been used to estimate velocity changes in fault zones, in volcanoes, in a mining environment, and in ultrasound experiments. This method uses multiple scattered waves, which travelled through the material along numerous paths, to infer tiny temporal changes in the wave velocity. The applied method has the potential to be used as a "damage-gauge" for monitoring velocity changes as a sign of damage evolution into masonry and concrete structures.

  2. An Automated Algebraic Method for Finding a Series of Exact Travelling Wave Solutions of Nonlinear Evolution Equations

    Institute of Scientific and Technical Information of China (English)

    柳银萍; 李志斌

    2003-01-01

    Based on a 0 of elliptic equation, a new algebraic method to construct a series of exact solutions for nonlinear evolution equations is proposed, meanwhile, its complete implementation TRWS in Maple is presented. The TRWS can output a series of travelling wave solutions entirely automatically, which include polynomial solutions, exponential function solutions, triangular function solutions, hyperbolic function solutions, rational function solutions, Jacobi elliptic function solutions, and Weierstrass elliptic function solutions. The effectiveness of the package is illustrated by applying it to a variety of equations. Not only are previously known solutions recovered but also new solutions and more general form of solutions are obtained.

  3. The Power of Principled Bayesian Methods in the Study of Stellar Evolution

    CERN Document Server

    von Hippel, Ted; Stenning, David C; Robinson, Elliot; Jeffery, Elizabeth; Stein, Nathan; Jefferys, William H; O'Malley, Erin

    2016-01-01

    It takes years of effort employing the best telescopes and instruments to obtain high-quality stellar photometry, astrometry, and spectroscopy. Stellar evolution models contain the experience of lifetimes of theoretical calculations and testing. Yet most astronomers fit these valuable models to these precious datasets by eye. We show that a principled Bayesian approach to fitting models to stellar data yields substantially more information over a range of stellar astrophysics. We highlight advances in determining the ages of star clusters, mass ratios of binary stars, limitations in the accuracy of stellar models, post-main-sequence mass loss, and the ages of individual white dwarfs. We also outline a number of unsolved problems that would benefit from principled Bayesian analyses.

  4. Key Elements of Robustness in Binary Black Hole Evolutions using Spectral Methods

    CERN Document Server

    Szilagyi, Bela

    2014-01-01

    As a network of advanced-era gravitational wave detectors is nearing its design sensitivity, efficient and accurate waveform modeling becomes more and more relevant. Understanding of the nature of the signal being sought can have an order unity effect on the event rates seen in these instruments. The paper provides a description of key elements of the Spectral Einstein Code ({\\tt SpEC}), with details of our spectral adaptive mesh refinement (AMR) algorithm that has been optimized for binary black hole (BBH) evolutions. We expect that the gravitational waveform catalog produced by our code will have a central importance in both the detection and parameter estimation of gravitational waves in these instruments.

  5. Laplace method for the evolution of the fragmentation function of Bc mesons

    Science.gov (United States)

    Boroun, G. R.; Zarrin, S.; Dadfar, S.

    2016-09-01

    In high-energy processes, the predominant mechanism for b bar c bound states is the production of a high-energy b bar or c quark, which fragments into the b bar c state. An approximate approach for the evolution of the fragmentation functions for the production of the S-wave states of Bc and Bc* is presented using Laplace transform technique in the leading order (LO) and next-to-leading order (NLO) analyses. The cross sections, as a function of the transverse momentum for the direct hadro-production b bar (c) →Bc and b bar (c) →Bc* based on the nonrelativistic quantum chromodynamics (QCD) factorization, are determined and compared with the Large Hadron Collider (LHC) and Tevatron data at the 1S-wave state.

  6. Novel Control Vector Parameterization Method with Differential Evolution Algorithm and Its Application in Dynamic Optimization of Chemical Processes

    Institute of Scientific and Technical Information of China (English)

    SUN Fan; ZHONG Weimin; CHENG Hui; QIAN Feng

    2013-01-01

    Two general approaches are adopted in solving dynamic optimization problems in chemical processes,namely,the analytical and numerical methods.The numerical method,which is based on heuristic algorithms,has been widely used.An approach that combines differential evolution (DE) algorithm and control vector parameterization (CVP) is proposed in this paper.In the proposed CVP,control variables are approximated with polynomials based on state variables and time in the entire time interval.Region reduction strategy is used in DE to reduce the width of the search region,which improves the computing efficiency.The results of the case studies demonstrate the feasibility and efficiency of the proposed methods.

  7. CURRENT STATE AND EVOLUTION PERSPECTIVES FOR MANAGEMENT ACCOUNTING IN THE ENERGY SECTOR BY IMPLEMENTING THE ABC METHOD

    Directory of Open Access Journals (Sweden)

    Rof Letitia Maria

    2011-07-01

    Full Text Available Based on a controversial issue, namely determining and controlling costs in the energy sector, the present study falls within the scope of management accounting and control. This scientific approach was initiated as a result of personal research concerns in the area of accounting, starting from the need to know and quantify costs in a sector of the economy that is less exploited. The main objective of this scientific approach is to address the evolution of the energy sector in a national and international context, in terms of economy and finances, with the aim to underline the need to organize and conduct management accounting in this sector. We will present a few particularities of the energy system, the current status of implementation of a medium and long term strategy aimed at developing the energy sector, as well as the need to adopt modern costing methods in this sector, which ensure operative cost control and performance growth of the entities that operate in this sector. Information on the reviewed topic was conducted by studying the national and international literature in the field, by analyzing the associated legislation, by consulting specialized web-sites and various articles in the database. The main research methods used in this scientific approach were analysis and synthesis, and qualitative research was the type of used research. The results of the research will materialize in providing the necessary conditions for designing an econometric model for implementing the ABC method, the conceptual and ideological delimitation of the ABC method, the deepening of the positive and negative aspects that the implementation of the Activity Based Costing involves. The major implication for the researched field is ensuring success for the implementation of a modern costing method in the energy sector, underlining the shortcomings of the traditional costing methods. The added value of the paper consists in conducting a rigorous study of the

  8. Evolution of Self-Reporting Methods for Identifying Discrete Emotions in Science Classrooms

    Science.gov (United States)

    Ritchie, Stephen M.; Hudson, Peter; Bellocchi, Alberto; Henderson, Senka; King, Donna; Tobin, Kenneth

    2016-01-01

    Emotion researchers have grappled with challenging methodological issues in capturing emotions of participants in naturalistic settings such as school or university classrooms. Self-reporting methods have been used frequently, yet these methods are inadequate when used alone. We argue that the self-reporting methods of emotion diaries and…

  9. Shape Optimization for Drag Reduction in Linked Bodies using Evolution Strategies and the Hybrid Wavelet Collocation - Brinkman Penalization Method

    Science.gov (United States)

    Vasilyev, Oleg V.; Gazzola, Mattia; Koumoutsakos, Petros

    2010-11-01

    In this talk we discuss preliminary results for the use of hybrid wavelet collocation - Brinkman penalization approach for shape optimization for drag reduction in flows past linked bodies. This optimization relies on Adaptive Wavelet Collocation Method along with the Brinkman penalization technique and the Covariance Matrix Adaptation Evolution Strategy (CMA-ES). Adaptive wavelet collocation method tackles the problem of efficiently resolving a fluid flow on a dynamically adaptive computational grid, while a level set approach is used to describe the body shape and the Brinkman volume penalization allows for an easy variation of flow geometry without requiring body-fitted meshes. We perform 2D simulations of linked bodies in order to investigate whether flat geometries are optimal for drag reduction. In order to accelerate the costly cost function evaluations we exploit the inherent parallelism of ES and we extend the CMA-ES implementation to a multi-host framework. This framework allows for an easy distribution of the cost function evaluations across several parallel architectures and it is not limited to only one computing facility. The resulting optimal shapes are geometrically consistent with the shapes that have been obtained in the pioneering wind tunnel experiments for drag reduction using Evolution Strategies by Ingo Rechenberg.

  10. Method of multiple internal reflections in description of tunneling evolution through barriers

    CERN Document Server

    Olkhovsky, Vladislav S

    2000-01-01

    A method of a non-stationary description of tunneling of a particle through the one-dimensional and spherically symmetric rectangular barriers on the basis of analisis of multiple internal reflections of wave packets in relation on the barrier boundaries, named as the Method of multiple internal reflections, is presented at the first time. For the one-dimensional problem the applicability of this method is proved, its specific features are analyzed. For the spherically symmetric problem the amplitudes of the transmitted and reflected wave packets, times of tunneling and reflection in relation to the barrier are calculated using this method. The effect of Hartman-Fletcher is analyzed.

  11. A Differential Evolution Based MPPT Method for Photovoltaic Modules under Partial Shading Conditions

    Directory of Open Access Journals (Sweden)

    Kok Soon Tey

    2014-01-01

    Full Text Available Partially shaded photovoltaic (PV modules have multiple peaks in the power-voltage (P-V characteristic curve and conventional maximum power point tracking (MPPT algorithm, such as perturbation and observation (P&O, which is unable to track the global maximum power point (GMPP accurately due to its localized search space. Therefore, this paper proposes a differential evolution (DE based optimization algorithm to provide the globalized search space to track the GMPP. The direction of mutation in the DE algorithm is modified to ensure that the mutation always converges to the best solution among all the particles in the generation. This helps to provide the rapid convergence of the algorithm. Simulation of the proposed PV system is carried out in PSIM and the results are compared to P&O algorithm. In the hardware implementation, a high step-up DC-DC converter is employed to verify the proposed algorithm experimentally on partial shading conditions, load variation, and solar intensity variation. The experimental results show that the proposed algorithm is able to converge to the GMPP within 1.2 seconds with higher efficiency than P&O.

  12. Methods of information geometry in computational system biology (consistency between chemical and biological evolution).

    Science.gov (United States)

    Astakhov, Vadim

    2009-01-01

    Interest in simulation of large-scale metabolic networks, species development, and genesis of various diseases requires new simulation techniques to accommodate the high complexity of realistic biological networks. Information geometry and topological formalisms are proposed to analyze information processes. We analyze the complexity of large-scale biological networks as well as transition of the system functionality due to modification in the system architecture, system environment, and system components. The dynamic core model is developed. The term dynamic core is used to define a set of causally related network functions. Delocalization of dynamic core model provides a mathematical formalism to analyze migration of specific functions in biosystems which undergo structure transition induced by the environment. The term delocalization is used to describe these processes of migration. We constructed a holographic model with self-poetic dynamic cores which preserves functional properties under those transitions. Topological constraints such as Ricci flow and Pfaff dimension were found for statistical manifolds which represent biological networks. These constraints can provide insight on processes of degeneration and recovery which take place in large-scale networks. We would like to suggest that therapies which are able to effectively implement estimated constraints, will successfully adjust biological systems and recover altered functionality. Also, we mathematically formulate the hypothesis that there is a direct consistency between biological and chemical evolution. Any set of causal relations within a biological network has its dual reimplementation in the chemistry of the system environment.

  13. An analytic method of space debris cloud evolution and its collision evaluation for constellation satellites

    Science.gov (United States)

    Zhang, Binbin; Wang, Zhaokui; Zhang, Yulin

    2016-09-01

    When a debris cloud is formed in the neighborhood of a constellation, the constellation satellites will face a serious threat of collision. In order to evaluate the collision probability in a long time scale, first we build an analytic model to describe the evolution process of the debris cloud. Under the perturbations of atmospheric drag, nonspherical gravity field, etc., results of numerical simulation indicate that after the breakup of an object, the distribution of debris cloud will evolve into a relatively stable band. Based on the stable distribution characteristic of the debris cloud, fragments are divided into several groups according their orbital heights and area-mass ratios. For each debris group, the dynamics of the distribution process under the perturbation of atmosphere drag is described by a partial differential equation (PDE). Solutions of those PDEs are obtained. And the distribution of the debris cloud can be easily propagated over long time scales. Applying this analytic model, the collision probability between a debris cloud and the Globalstar satellites is analyzed and computed. Results show that the collision probability is nearly 10,000 times of the average collision probability in the near Earth environment. Moreover, as the band distribution of the space debris cloud is stable, the collisional risk on constellation satellites will last for quite a long time.

  14. Episode-Based Evolution Pattern Analysis of Haze Pollution: Method Development and Results from Beijing, China.

    Science.gov (United States)

    Zheng, Guangjie; Duan, Fengkui; Ma, Yongliang; Zhang, Qiang; Huang, Tao; Kimoto, Takashi; Cheng, Yafang; Su, Hang; He, Kebin

    2016-05-01

    Haze episodes occurred in Beijing repeatedly in 2013, resulting in 189 polluted days. These episodes differed in terms of sources, formation processes, and chemical composition and thus required different control policies. Therefore, an overview of the similarities and differences among these episodes is needed. For this purpose, we conducted one-year online observations and developed a program that can simultaneously divide haze episodes and identify their shapes. A total of 73 episodes were identified, and their shapes were linked with synoptic conditions. Pure-haze events dominated in wintertime, whereas mixed haze-dust (PM2.5/PM10 haze-fog (Aerosol Water/PM2.5 ∼ 0.3) events dominated in spring and summer-autumn, respectively. For all types, increase of ratio of PM2.5 in PM10 was typically achieved before PM2.5 reached ∼150 μg/m(3). In all PM2.5 species observed, organic matter (OM) was always the most abundant component (18-60%), but it was rarely the driving factor: its relative contribution usually decreased as the pollution level increased. The only OM-driven episode observed was associated with intensive biomass-burning activities. In comparison, haze evolution generally coincided with increasing sulfur and nitrogen oxidation ratios (SOR and NOR), indicating the enhanced production of secondary inorganic species. Applicability of these conclusions required further tests with simultaneously multisite observations.

  15. An energy stable evolution method for simulating two-phase equilibria of multi-component fluids at constant moles, volume and temperature

    KAUST Repository

    Kou, Jisheng

    2016-02-25

    In this paper, we propose an energy-stable evolution method for the calculation of the phase equilibria under given volume, temperature, and moles (VT-flash). An evolution model for describing the dynamics of two-phase fluid system is based on Fick’s law of diffusion for multi-component fluids and the Peng-Robinson equation of state. The mobility is obtained from diffusion coefficients by relating the gradient of chemical potential to the gradient of molar density. The evolution equation for moles of each component is derived using the discretization of diffusion equations, while the volume evolution equation is constructed based on the mechanical mechanism and the Peng-Robinson equation of state. It is proven that the proposed evolution system can well model the VT-flash problem, and moreover, it possesses the property of total energy decay. By using the Euler time scheme to discretize this evolution system, we develop an energy stable algorithm with an adaptive choice strategy of time steps, which allows us to calculate the suitable time step size to guarantee the physical properties of moles and volumes, including positivity, maximum limits, and correct definition of the Helmhotz free energy function. The proposed evolution method is also proven to be energy-stable under the proposed time step choice. Numerical examples are tested to demonstrate efficiency and robustness of the proposed method.

  16. A new method to obtain approximate symmetry of nonlinear evolution equation from perturbations

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhi-Yong; Yong Xue-Lin; Chen Yu-Fu

    2009-01-01

    A novel method for obtaining the approximate symmetry of a partial differential equation with a small parameter is introduced. By expanding the independent variable and the dependent variable in the small parameter series, we obtain more affluent approximate symmetries. The method is applied to two perturbed nonlinear partial differential equations and new approximate solutions are derived.

  17. Synthesis and Characterization of Phosphine and Arsine Complexes of Ruthenium (Ii & Iii Ligated With 3-(4-Pyridyl-4-Substituted-Triazoline-5-Thione

    Directory of Open Access Journals (Sweden)

    R. N. Pandey

    2014-12-01

    Full Text Available Organometallic complexes of ruthenium (II & III with the formula [RuH(CO(Ef32L] and [RuCl2(Ef32L] (E = P/As; L = deprotonated mononegative bidentate 3-(4-pyridyl-triazoline-5-thione and its 4-phenyl substituted derivative were synthesized and characterized by elemental analysis, physico-chemical and spectroscopic methods. All new compounds were iso-structural with precursor complexes. Two triphenyl phosphine or triphenylarsine molecules are at trans-disposition and thioamide ligands behaves as bidentate (N, S donor in assigned octahedral structure.

  18. An analytical-based method for studying the nonlinear evolution of localized vortices in planar homogenous shear flows

    Science.gov (United States)

    Cohen, J.; Shukhman, I. G.; Karp, M.; Philip, J.

    2010-10-01

    Recent experimental and numerical studies have shown that the interaction between a localized vortical disturbance and the shear of an external base flow can lead to the formation of counter-rotating vortex pairs and hairpin vortices that are frequently observed in wall bounded and free turbulent shear flows as well as in subcritical shear flows. In this paper an analytical-based solution method is developed. The method is capable of following (numerically) the evolution of finite-amplitude localized vortical disturbances embedded in shear flows. Due to their localization in space, the surrounding base flow is assumed to have homogeneous shear to leading order. The method can solve in a novel way the interaction between a general family of unbounded planar homogeneous shear flows and any localized disturbance. The solution is carried out using Lagrangian variables in Fourier space which is convenient and enables fast computations. The potential of the method is demonstrated by following the evolved structures of large amplitude disturbances in three canonical base flows, including simple shear, plane stagnation (extensional) and pure rotation flows, and a general case. The results obtained by the current method for plane stagnation and simple shear flows are compared with the published results. The proposed method could be extended to other flows (e.g. geophysical and rotating flows) and to include periodic disturbances as well.

  19. A method to visualize the evolution of multiple interacting spatial systems

    Science.gov (United States)

    Heitzler, Magnus; Hackl, Jürgen; Adey, Bryan T.; Iosifescu-Enescu, Ionut; Lam, Juan Carlos; Hurni, Lorenz

    2016-07-01

    Integrated modeling approaches are being increasingly used to simulate the behavior of, and the interaction between, several interdependent systems. They are becoming more and more important in many fields, including, but not being limited to, civil engineering, hydrology and climate impact research. It is beneficial when using these approaches to be able to visualize both, the intermediary and final results of scenario-based analyses that are conducted in both, space and time. This requires appropriate visualization techniques that enable to efficiently navigate between multiple such scenarios. In recent years, several innovative visualization techniques have been developed that allow for such navigation purposes. These techniques, however, are limited to the representation of one system at a time. Improvements are possible with respect to the ability to visualize the results related to multiple scenarios for multiple interdependent spatio-temporal systems. To address this issue, existing multi-scenario navigation techniques based on small multiples and line graphs are extended by multiple system representations and inter-system impact representations. This not only allows to understand the evolution of the systems under consideration but also eases identifying events where one system influences another system significantly. In addition, the concept of selective branching is described that allows to remove otherwise redundant information from the visualization by considering the logical and temporal dependencies between these systems. This visualization technique is applied to a risk assessment methodology that allows to determine how different environmental systems (i.e. precipitation, flooding, and landslides) influence each other as well as how their impact on civil infrastructure affects society. The results of this work are concepts for improved visualization techniques for multiple interacting spatial systems. The successful validation with domain experts of

  20. Co-evolution of strain design methods based on flux balance and elementary mode analysis

    DEFF Research Database (Denmark)

    Machado, Daniel; Herrgard, Markus

    2015-01-01

    optimization to couple cellular growth with the production of a target product. This initiated the development of a family of strain design methods based on the concept of flux balance analysis. Another family of strain design methods, based on the concept of elementary mode analysis, has also been growing......More than a decade ago, the first genome-scale metabolic models for two of the most relevant microbes for biotechnology applications, Escherichia coli and Saccaromyces cerevisiae, were published. Shortly after followed the publication of OptKnock, the first strain design method using bilevel....... Although the computation of elementary modes is hindered by computational complexity, recent breakthroughs have allowed applying elementary mode analysis at the genome scale. Here we review and compare strain design methods and look back at the last 10 years of in silico strain design with constraint...

  1. Estimation of fatigue evolution of aluminum alloy plated with electroless NI–CO–P by using electromagnetic impedance method

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Katsuyuki

    2015-02-01

    We have developed a method for detecting fatigue in aluminum alloys that is based on a applying a ferromagnetic electroless Ni–Co–P plating and then using an electromagnetic impedance (EMI) method to determine its permeability properties by measuring the high-frequency AC impedance of a coil sensor in the presence of a static magnetic field. The results obtained confirmed that this method can estimate the fatigue evolution of a specimen until the point at which the cumulative strain becomes saturated by using measurements obtained by the EMI method under tensile deformation and FEM analysis results. - Highlights: • Plating aluminum alloy with Ni–Co–P film increases its fatigue strength by 13−16%. • The tensile direction is the stress induced “hard axis” of the Ni–Co–P plating. • In-plane permeability determines the coil impedance for out-of-plane excitation. • This method can measure fatigue up to saturation of the substrate's residual strain.

  2. Directed evolution methods for improving polypeptide folding and solubility and superfolder fluorescent proteins generated thereby

    Science.gov (United States)

    Waldo, Geoffrey S.

    2007-09-18

    The current invention provides methods of improving folding of polypeptides using a poorly folding domain as a component of a fusion protein comprising the poorly folding domain and a polypeptide of interest to be improved. The invention also provides novel green fluorescent proteins (GFPs) and red fluorescent proteins that have enhanced folding properties.

  3. Determination of organic acids evolution during apple cider fermentation using an improved HPLC analysis method

    NARCIS (Netherlands)

    Zhang, H.; Zhou, F.; Ji, B.; Nout, M.J.R.; Fang, Q.; Zhang, Z.

    2008-01-01

    An efficient method for analyzing ten organic acids in food, namely citric, pyruvic, malic, lactic, succinic, formic, acetic, adipic, propionic and butyric acids, using HPLC was developed. Boric acid was added into the mobile phase to separate lactic and succinic acids, and a post-column buffer solu

  4. Non-stationary random vibration analysis of a 3D train-bridge system using the probability density evolution method

    Science.gov (United States)

    Yu, Zhi-wu; Mao, Jian-feng; Guo, Feng-qi; Guo, Wei

    2016-03-01

    Rail irregularity is one of the main sources causing train-bridge random vibration. A new random vibration theory for the coupled train-bridge systems is proposed in this paper. First, number theory method (NTM) with 2N-dimensional vectors for the stochastic harmonic function (SHF) of rail irregularity power spectrum density was adopted to determine the representative points of spatial frequencies and phases to generate the random rail irregularity samples, and the non-stationary rail irregularity samples were modulated with the slowly varying function. Second, the probability density evolution method (PDEM) was employed to calculate the random dynamic vibration of the three-dimensional (3D) train-bridge system by a program compiled on the MATLAB® software platform. Eventually, the Newmark-β integration method and double edge difference method of total variation diminishing (TVD) format were adopted to obtain the mean value curve, the standard deviation curve and the time-history probability density information of responses. A case study was presented in which the ICE-3 train travels on a three-span simply-supported high-speed railway bridge with excitation of random rail irregularity. The results showed that compared to the Monte Carlo simulation, the PDEM has higher computational efficiency for the same accuracy, i.e., an improvement by 1-2 orders of magnitude. Additionally, the influences of rail irregularity and train speed on the random vibration of the coupled train-bridge system were discussed.

  5. Prediction of the effect of defect parameters on the thermal contrast evolution during flash thermography by finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Ziqiao; Yuan, Maodan; Wu, Hu; Zhang, Jianjai; Kim, Hak Joon; Song, Sung Jin [School of Mechanical Engineering, Sungkyunkwan University, Suwon (Korea, Republic of)

    2014-02-15

    A 3D model based on the finite element method (FEM) was built to simulate the infrared thermography (IRT) inspection process. Thermal contrast is an important parameter in IRT and was proven to be a function of defect parameters. Parametric studies were conducted on internal defects with different depths, thicknesses, and orientations. Thermal contrast evolution profiles with respect to the time of the defect and host material were obtained through numerical simulation. The thermal contrast decreased with defect depth and slightly increased with defect thickness. Different orientations of thin defects were detected with IRT, but doing so for thick defects was difficult. These thermal contrast variations with the defect depth, thickness, and orientation can help in optimizing the experimental process and interpretation of data from IRT.

  6. Gravitational Radiation Damping and Evolution of the Orbit of Compact Binary Stars (Solution by the Second Perturbation Method)

    Indian Academy of Sciences (India)

    Lin-Sen Li

    2014-06-01

    The influence of the gravitational radiation damping on the evolution of the orbital elements of compact binary stars is examined by using the method of perturbation. The perturbation equations with the true anomaly as an independent variable are given. This effect results in both the secular and periodic variation of the semi-major axis, the eccentricity, the mean longitude at the epoch and the mean longitude. However, the longitude of periastron exhibits no secular variation, but only periodic variation. The effect of secular variation of the orbit would lead to collapse of the system of binary stars. The deduced formulae are applied to the calculation of secular variation of the orbital elements for three compact binary stars: PSR 1913+16, PSR J0737-3039 and M33X-7. The results obtained are discussed.

  7. Study on Reverse Reconstruction Method of Vehicle Group Situation in Urban Road Network Based on Driver-Vehicle Feature Evolution

    Directory of Open Access Journals (Sweden)

    Xiaoyuan Wang

    2017-01-01

    Full Text Available Vehicle group situation is the status and situation of dynamic permutation which is composed of target vehicle and neighboring traffic entities. It is a concept which is frequently involved in the research of traffic flow theory, especially the active vehicle security. Studying vehicle group situation in depth is of great significance for traffic safety. Three-lane condition was taken as an example; the characteristics of target vehicle and its neighboring vehicles were synthetically considered to restructure the vehicle group situation in this paper. The Gamma distribution theory was used to identify the vehicle group situation when target vehicle arrived at the end of the study area. From the perspective of driver-vehicle feature evolution, the reverse reconstruction method of vehicle group situation in the urban road network was proposed. Results of actual driving, virtual driving, and simulation experiments showed that the model established in this paper was reasonable and feasible.

  8. An analytic electromagnetic calculation method for performance evolution of doubly fed induction generators for wind turbines

    DEFF Research Database (Denmark)

    Zhang, Wen-juan; Huang, Shou-dao; Chen, Zhe

    2013-01-01

    An analytic electromagnetic calculation method for doubly fed induction generator (DFIG) in wind turbine system was presented. Based on the operation principles, steady state equivalent circuit and basic equations of DFIG, the modeling for electromagnetic calculation of DFIG was proposed. The ele......An analytic electromagnetic calculation method for doubly fed induction generator (DFIG) in wind turbine system was presented. Based on the operation principles, steady state equivalent circuit and basic equations of DFIG, the modeling for electromagnetic calculation of DFIG was proposed....... The electromagnetic calculation of DFIG was divided into three steps: the magnetic flux calculation, parameters derivation and performance checks. For each step, the detailed numeric calculation formulas were all derived. Combining the calculation formulas, the whole electromagnetic calculation procedure...

  9. CHIME dating method and its application to the analysis of evolutional history of orogenic belts

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Kazuhiro; Adachi, Mamoru; Kato, Takenori; Yogo, Setsuo [Nagoya Univ. (Japan)

    1999-03-01

    This paper outlines the CHIME (chemical Th-U-total Pb isochron method: Suzuki and Adachi, 1991a, b; Adachi and Suzuki, 1992) dating method and reviews its application to the event analysis of orogenic belts. The reviewed examples of the CHIME geochronology include (1) the electron microprobe observations of Pb diffusion in metamorphosed detrital monazites from high-grade Ryoke paragneisses (Suzuki et al., 1994), (2) the recycled Precambrian clastic materials from the Mino terrane (Adachi and Suzuki, 1993, 1994), (3) the late Permian-early Triassic metamorphism and plutonism in the Hida terrane (Suzuki and Adachi, 1991b, 1994), (4) the relationship between the Hikami Granite and Siluro-Devonian clastic rocks in the South Kitakami terrane (Suzuki et al, 1992; Adachi et al., 1994), and (5) the denudation history of the high T/P Ryoke metamorphic belt (Suzuki and Adachi, 1998). The CHIME dating method is based on precise electron microprobe analyses of Th, U and Pb as low as 0.01wt.% in an area of 5 {mu}m across within a single grain of compositionally ununiformed Th-and U-bearing accessory minerals like monazite and zircon. This method has an advantage of high spatial resolution, and provides a new vista on the study of igneous, metamorphic and sedimentary rocks that underwent complex thermo-tectonic history. Monazite is most suitable to the CHIME dating, since it shows a concordant Th-U-Pb relation, contains 5-20 wt.% ThO{sub 2} and 0.1-1.5wt.% UO{sub 2} that can produce 0.01-0.06wt.% PbO during 50 Myr, and remains immune to significant Pb-loss during the sillimanite grade metamorphism; it has great chronological potential for the analysis of the detailed sequence of geologic events. (author)

  10. Phase-vanishing method with acetylene evolution and its utilization in several organic syntheses.

    Science.gov (United States)

    Matake, Ryosuke; Niwa, Yuki; Matsubara, Hiroshi

    2015-05-15

    A novel quadraphasic phase-vanishing system in which acetylene is evolved from calcium carbide and directly applied in situ to the Sonogashira coupling reaction was developed. This method, which provides a safe, convenient, and one-pot means to utilize gaseous reagents without special equipment, was also applied to a Cu-catalyzed azide-alkyne cycloaddition (CuAAC) reaction and a three-component aldehyde-alkyne-amine (A(3)) coupling reaction with excellent results.

  11. Bed Evolution under Rapidly Varying Flows by a New Method for Wave Speed Estimation

    Directory of Open Access Journals (Sweden)

    Khawar Rehman

    2016-05-01

    Full Text Available This paper proposes a sediment-transport model based on coupled Saint-Venant and Exner equations. A finite volume method of Godunov type with predictor-corrector steps is used to solve a set of coupled equations. An efficient combination of approximate Riemann solvers is proposed to compute fluxes associated with sediment-laden flow. In addition, a new method is proposed for computing the water depth and velocity values along the shear wave. This method ensures smooth solutions, even for flows with high discontinuities, and on domains with highly distorted grids. The numerical model is tested for channel aggradation on a sloping bottom, dam-break cases at flume-scale and reach-scale with flat bottom configurations and varying downstream water depths. The proposed model is tested for predicting the position of hydraulic jump, wave front propagation, and for predicting magnitude of bed erosion. The comparison between results based on the proposed scheme and analytical, experimental, and published numerical results shows good agreement. Sensitivity analysis shows that the model is computationally efficient and virtually independent of mesh refinement.

  12. Optimization of air quantity regulation in mine ventilation networks using the improved differential evolution algorithm and critical path method

    Institute of Scientific and Technical Information of China (English)

    Chen Kaiyan; Si Junhong; Zhou Fubao; Zhang Renwei; Shao He; Zhao Hongmei

    2015-01-01

    In mine ventilation networks, the reasonable airflow distribution is very important for the production safety and economy. Three basic problems of the natural, full-controlled and semi-controlled splitting were reviewed in the paper. Aiming at the high difficulty semi-controlled splitting problem, the general nonlinear multi-objectives optimization mathematical model with constraints was established based on the theory of mine ventilation networks. A new algorithm, which combined the improved differential evaluation and the critical path method (CPM) based on the multivariable separate solution strategy, was put forward to search for the global optimal solution more efficiently. In each step of evolution, the feasible solutions of air quantity distribution are firstly produced by the improved differential evolu-tion algorithm, and then the optimal solutions of regulator pressure drop are obtained by the CPM. Through finite steps iterations, the optimal solution can be given. In this new algorithm, the population of feasible solutions were sorted and grouped for enhancing the global search ability and the individuals in general group were randomly initialized for keeping diversity. Meanwhile, the individual neighbor-hood in the fine group which may be closely to the optimal solutions were searched locally and slightly for achieving a balance between global searching and local searching, thus improving the convergence rate. The computer program was developed based on this method. Finally, the two ventilation networks with single-fan and multi-fans were solved. The results show that this algorithm has advantages of high effectiveness, fast convergence, good robustness and flexibility. This computer program could be used to solve large-scale generalized ventilation networks optimization problem in the future.

  13. Protein consensus-based surface engineering (ProCoS): a computer-assisted method for directed protein evolution.

    Science.gov (United States)

    Shivange, Amol V; Hoeffken, Hans Wolfgang; Haefner, Stefan; Schwaneberg, Ulrich

    2016-12-01

    Protein consensus-based surface engineering (ProCoS) is a simple and efficient method for directed protein evolution combining computational analysis and molecular biology tools to engineer protein surfaces. ProCoS is based on the hypothesis that conserved residues originated from a common ancestor and that these residues are crucial for the function of a protein, whereas highly variable regions (situated on the surface of a protein) can be targeted for surface engineering to maximize performance. ProCoS comprises four main steps: (i) identification of conserved and highly variable regions; (ii) protein sequence design by substituting residues in the highly variable regions, and gene synthesis; (iii) in vitro DNA recombination of synthetic genes; and (iv) screening for active variants. ProCoS is a simple method for surface mutagenesis in which multiple sequence alignment is used for selection of surface residues based on a structural model. To demonstrate the technique's utility for directed evolution, the surface of a phytase enzyme from Yersinia mollaretii (Ymphytase) was subjected to ProCoS. Screening just 1050 clones from ProCoS engineering-guided mutant libraries yielded an enzyme with 34 amino acid substitutions. The surface-engineered Ymphytase exhibited 3.8-fold higher pH stability (at pH 2.8 for 3 h) and retained 40% of the enzyme's specific activity (400 U/mg) compared with the wild-type Ymphytase. The pH stability might be attributed to a significantly increased (20 percentage points; from 9% to 29%) number of negatively charged amino acids on the surface of the engineered phytase.

  14. Generalized Kudryashov method for solving some (3+1-dimensional nonlinear evolution equations

    Directory of Open Access Journals (Sweden)

    Md. Shafiqul Islam

    2015-06-01

    Full Text Available In this work, we have applied the generalized Kudryashov methods to obtain the exact travelling wave solutions for the (3+1-dimensional Jimbo-Miwa (JM equation, the (3+1-dimensional Kadomtsev-Petviashvili (KP equation and the (3+1-dimensional Zakharov-Kuznetsov (ZK. The attained solutions show distinct physical configurations. The constraints that will guarantee the existence of specific solutions will be investigated. These solutions may be useful and desirable for enlightening specific nonlinear physical phenomena in genuinely nonlinear dynamical systems.

  15. Spectroscopic bulge-disc decomposition: a new method to study the evolution of lenticular galaxies

    CERN Document Server

    Johnston, E J; Merrifield, M R; Bedregal, A G

    2012-01-01

    A new method for spectroscopic bulge-disc decomposition is presented, in which the spatial light profile in a two-dimensional spectrum is decomposed wavelength-by-wavelength into bulge and disc components, allowing separate one-dimensional spectra for each component to be constructed. This method has been applied to observations of a sample of nine S0s in the Fornax Cluster in order to obtain clean high-quality spectra of their individual bulge and disc components. So far this decomposition has only been fully successful when applied to galaxies with clean light profiles, consequently limiting the number of galaxies that could be separated into bulge and disc components. Lick index stellar population analysis of the component spectra reveals that in those galaxies where the bulge and disc could be distinguished, the bulges have systematically higher metallicities and younger stellar populations than the discs. This correlation is consistent with a picture in which S0 formation comprises the shutting down of s...

  16. An analytic electromagnetic calculation method for performance evolution of doubly fed induction generators for wind turbines

    Institute of Scientific and Technical Information of China (English)

    张文娟; 黄守道; 高剑; CHEN; Zhe

    2013-01-01

    An analytic electromagnetic calculation method for doubly fed induction generator(DFIG) in wind turbine system was presented. Based on the operation principles, steady state equivalent circuit and basic equations of DFIG, the modeling for electromagnetic calculation of DFIG was proposed. The electromagnetic calculation of DFIG was divided into three steps: the magnetic flux calculation, parameters derivation and performance checks. For each step, the detailed numeric calculation formulas were all derived. Combining the calculation formulas, the whole electromagnetic calculation procedure was established, which consisted of three iterative calculation loops, including magnetic saturation coefficient, electromotive force and total output power. All of the electromagnetic and performance data of DIFG can be calculated conveniently by the established calculation procedure, which can be used to evaluate the new designed machine. A 1.5 MW DFIG designed by the proposed procedure was built, for which the whole type tests including no-load test, load test and temperature rising test were carried out. The test results have shown that the DFIG satisfies technical requirements and the test data fit well with the calculation results which prove the correctness of the presented calculation method.

  17. Evolution of Chinese tea-drinking methods%中国饮茶方式的历史演进

    Institute of Scientific and Technical Information of China (English)

    周文劲

    2012-01-01

    Before the Tang dynasty, the Chinese people made tea by boiling the fresh tea leaves and then drank like dranking soup. This method was employed till the Song dynasty, when tea was prepared by whipping, followed by the method of infusing loose tea leaves using hot water during the Ming and Qing dynasties. The long-term evolution of Chinese tea-drinking methods is an epitome of the development of Chinese tea culture, and the essence of the tea culture as well.%中国饮茶方式历经了由唐以前的生煮羹饮、唐代的煎茶、宋代的点茶到明清瀹饮法的漫漫演进,中国饮茶方式的历史演变也是中华茶文化发展进程的缩影,也是中华茶文化的精华所在。

  18. THE EVOLUTION OF MARKETING METHODS IN A TOURISM ASSOCIATION FROM ROMANIA

    Directory of Open Access Journals (Sweden)

    MARIA STOIAN

    2011-01-01

    Full Text Available The aim of this article is to present how to apply marketing methods, older and newer ones, to the action plan of a tourism association. I chose for this study the National Association of Rural, Ecological and Cultural Tourism from Romania (ANTREC, since I had available a series of chronological information on which I was capable to adapt the idea that I wanted to highlight. The conclusions that I reached from this analysis are closely related to the idea that, like other industries, the type of marketing practiced in a tourism association must adapt continually, to be innovative and to highlight by his unique style and his results. For the preparation work I used only the database of ANTREC Romania.

  19. Microstructural evolution of directionally solidified DZ125 superalloy castings with different solidification methods

    Directory of Open Access Journals (Sweden)

    Ge Bingming

    2013-01-01

    Full Text Available The properties of Ni-base superalloy castings are closely related to the uniformity of their as-cast microstructure, and different solidification methods have serious effect on microstructural uniformity. In this paper, the influences of high rate solidification (HRS process (with or without superheating and liquid metal cooling (LMC process on the microstructure of DZ125 superalloy were investigated. Blade-shape castings were solidified at rates of 40 μm·s-1 to 110 μm·s-1 using HRS process and a comparative experiment was carried out at a rate of 70 μm·s-1 by LMC process. The optical microscope (OM, scanning electron microscope (SEM were used to observe the microstructure and the grain size was analyzed using electron back scattered diffraction (EBSD technique. Results show that for the castings by either HRS or LMC process, the primary dendrite arm spacing and size of γ' precipitates decrease with increasing the withdrawal rate; the dendrites and γ' precipitates at the upper section of the blade are coarser than those in the middle, especially for the HRS castings without high superheating technique. When the withdrawal rate is 70 μm·s-1, the castings by HRS with high superheating technique have the smallest PDAS with fine γ' precipitates; while the size distribution of γ' precipitates is more homogenous in LMC castings, and the number of larger grains in LMC castings is smaller than that in the HRS castings. Moreover, high superheating technique yields smaller grains in the castings. Both the LMC method and HRS with high superheating technique can be used to prepare castings with reduced maximum grain size.

  20. Evolution of in Fe-doped manganites synthesized by the ball-milling method

    Science.gov (United States)

    Cherif, W.; Alonso, J. A.; Elhalouani, F.

    2017-01-01

    Manganites-based perovskites, having the general formula Ln0.67A0.33Mn1- x M x O3 where Ln is a rare earth element (Ln = Pr, La, ldots) and A is an alkaline earth element (A = Sr, Ba, Ca, ldots), were the center of interest of many studies because of their outstanding physicochemical properties and because they can play an important role in various applications. The aim of this work is the development with mechanical alloying method and study of physicochemical properties of new manganites. This work focuses on the development and characterization of series La0.67Ca0.11Sr0.22Mn1- x Fe x O3 ( 0≤ x≤ 0.3. The structural study showed that the cell parameters of the samples increase with the increase in the rate of iron and causing the expansion of the orthorhombic distortion. This result is confirmed by the tolerance factor tg (0.75 < tg < 0.95: orthorhombic structure). The magnetic study showed that the substitution of Mn by Fe in these series indicates a ferromagnetic-paramagnetic transition. This transition accompanied with a decrease in the Curie temperature (T_C).

  1. Long-term effects of user preference-oriented recommendation method on the evolution of online system

    Science.gov (United States)

    Shi, Xiaoyu; Shang, Ming-Sheng; Luo, Xin; Khushnood, Abbas; Li, Jian

    2017-02-01

    As the explosion growth of Internet economy, recommender system has become an important technology to solve the problem of information overload. However, recommenders are not one-size-fits-all, different recommenders have different virtues, making them be suitable for different users. In this paper, we propose a novel personalized recommender based on user preferences, which allows multiple recommenders to exist in E-commerce system simultaneously. We find that output of a recommender to each user is quite different when using different recommenders, the recommendation accuracy can be significantly improved if each user is assigned with his/her optimal personalized recommender. Furthermore, different from previous works focusing on short-term effects on recommender, we also evaluate the long-term effect of the proposed method by modeling the evolution of mutual feedback between user and online system. Finally, compared with single recommender running on the online system, the proposed method can improve the accuracy of recommendation significantly and get better trade-offs between short- and long-term performances of recommendation.

  2. A new generalized compound Riccati equations rational expansion method to construct many new exact complexiton solutions of nonlinear evolution equations with symbolic computation

    Energy Technology Data Exchange (ETDEWEB)

    Li Wenting [Department of Applied Mathematics, Dalian University of Technology, Dalian 116024 (China)], E-mail: lwt.wentinglee@yahoo.com.cn; Zhang Hongqing [Department of Applied Mathematics, Dalian University of Technology, Dalian 116024 (China)

    2009-03-15

    Based on symbolic computation and the idea of rational expansion method, a new generalized compound Riccati equations rational expansion method (GCRERE) is suggested to construct a series of exact complexiton solutions for nonlinear evolution equations. Compared with most existing rational expansion methods and other sophisticated methods, the proposed method not only recover some known solutions, but also find some new and general complexiton solutions. The validity and reliability of the method is tested by its application to the (2+1)-dimensional Burgers equation. It is shown that more complexiton solutions can be found by this new method.

  3. Evolutionary epistemology as a scientific method: a new look upon the units and levels of evolution debate.

    Science.gov (United States)

    Gontier, Nathalie

    2010-09-01

    Evolutionary epistemology can provide a unified scientific methodology that enables scholars to study the evolution of life as well as the evolution of cognition, science, culture and any other phenomenon displayed by living organisms. In this article, three heuristics are provided that allow for a thorough search for the units, levels and mechanisms of evolution. Contrary to previous approaches, units, levels and mechanisms are not identified by pointing out essential features, but rather ostensive definitions are preferred. That is, units are considered as such if a level of evolution and a mechanism of evolution is identifiable. Levels are levels if one can point out units that evolve at that level according to evolutionary mechanisms, and mechanisms are considered as such if one can point out units and levels where the mechanism is active.

  4. BOOK REVIEW: Structures in the Universe by Exact Methods: Formation, Evolutions, Interactions (Cambridge Monographs on Mathematical Physics) Structures in the Universe by Exact Methods: Formation, Evolutions, Interactions (Cambridge Monographs on Mathematical Physics)

    Science.gov (United States)

    Coley, Alan

    2010-05-01

    In this book the use of inhomogeneous models in cosmology, both in modelling structure formation and interpreting cosmological observations, is discussed. The authors concentrate on exact solutions, and particularly the Lemaitre-Tolman (LT) and Szekeres models (the important topic of averaging is not discussed). The book serves to demonstrate that inhomogeneous metrics can generate realistic models of cosmic structure formation and nonlinear evolution and shows that general relativity has a lot more to offer to cosmology than just the standard spatially homogeneous FLRW model. I would recommend this book to people working in theoretical cosmology. In the introduction (and in the concluding chapter and throughout the book) a reasonable discussion of the potential problems with the standard FLRW cosmology is presented, and a list of examples illustrating the limitations of standard FLRW cosmology are discussed (including potential problems with perturbation methods). In particular, the authors argue that the assumptions of isotropy and spatial homogeneity (and consequently the Copernican principle) must be properly challenged and revisited. Indeed, it is possible for `good old general relativity' to be used to explain cosmological observations without introducing speculative elements. In part I of the book the necessary background is presented (readers need a background in general relativity theory at an advanced undergraduate or graduate level). There is a good (and easy to read) review of the exact spherically symmetric dust Lemaitre-Tolman model (LT) (often denoted the LTB model) and the Lemaitre and Szekeres models. Light propogation (i.e. null geodesics, for both central and off-center observers) in exact inhomogeneous (LT) models is reviewed. In part II a number of applications of exact inhomogeneous models are presented (taken mainly from the authors' own work). In chapter 4, the evolution of exact inhomogeneous models (primarily the LT model, but also the

  5. Structure evolution and thermal stability of La2O3-doped mullite fibers viasol-gel method

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; WENG Duan; WU Xiaodong

    2012-01-01

    The lanthana-doped mullite fibers were prepared via a sol-gel method from the aluminum isopropoxide-aluminum nitrate-tetraethyl orthosilicate system.The structure evolution and thermal stability of the mullite fibers were investigated by means of X-ray diffraction (XRD),Fourier transform infrared (FT-IR) spectroscopy,differential scanning calorimetry (DSC),scanning electron microscopy (SEM) and transmission electron microscopy (TEM).The results showed that the fibers obtained after calcination at 1000℃ was in the form of A12O3-rich mullite,which tended to transform to stoichiometric mullite with the lanthana content increasing.The lattice parameter a exhibited a decline trend with the lanthana content increasing,while b showed an upward tendency.Correspondingly,the redshift of Si-O-Si bond from 1255 to 1245 cm-1 was observed.The grain growth was inhibited for the doped fibers,among which the 5% La2O3-doped sample presented a minimum crystallite size (17.2 nm) after calcination at 1000 ℃ for 1 h.

  6. Similarity measure and topology evolution of foreign exchange markets using dynamic time warping method: Evidence from minimal spanning tree

    Science.gov (United States)

    Wang, Gang-Jin; Xie, Chi; Han, Feng; Sun, Bo

    2012-08-01

    In this study, we employ a dynamic time warping method to study the topology of similarity networks among 35 major currencies in international foreign exchange (FX) markets, measured by the minimal spanning tree (MST) approach, which is expected to overcome the synchronous restriction of the Pearson correlation coefficient. In the empirical process, firstly, we subdivide the analysis period from June 2005 to May 2011 into three sub-periods: before, during, and after the US sub-prime crisis. Secondly, we choose NZD (New Zealand dollar) as the numeraire and then, analyze the topology evolution of FX markets in terms of the structure changes of MSTs during the above periods. We also present the hierarchical tree associated with the MST to study the currency clusters in each sub-period. Our results confirm that USD and EUR are the predominant world currencies. But USD gradually loses the most central position while EUR acts as a stable center in the MST passing through the crisis. Furthermore, an interesting finding is that, after the crisis, SGD (Singapore dollar) becomes a new center currency for the network.

  7. Construction of a mutant library of horseradish peroxidase gene by directed evolution and development of an in situ screening method

    Directory of Open Access Journals (Sweden)

    F.M. Mendive

    2003-03-01

    Full Text Available A process of directed evolution applied to obtain a library of mutants of horseradish peroxidase (HRP enzyme is described. We have introduced slight variations into the original DNA shuffling protocol. A DNA template was prepared by PCR amplification and digested with Dnase I during 1 hour. Dnase I products were concentrated by precipitation with isopropanol. Gel electrophoresis showed fragments of the desired size range (20-600 pb without a full-length template remaining in the reaction mixture. A high concentration of fragments was crucial for performing PCR without primers. In this case, a template concentration of 32.5 ng/mu l was appropriate. Amplification of recombinant genes in a standard PCR reaction (template dilution 1:100 produced a smear with a low yield for the full-length sequence. A single product of the correct size was obtained by PCR with nested primers separated from the previously used primers by 40 pb. In our laboratory, native HRP has been functionally expressed in a baculovirus expression vector system. The purpose is to develop the screening of the first generation of random mutants in this system. To facilitate detection of those clones that have high peroxidase activity, we developed a rapid method: after five days postinfection agarose plates with six wells were covered with DAB (3,3´-diaminobenzidine and H2O2. The appearance of brown-black stain allows visualization of up to 100 active clones/well in only 1 min.

  8. Modelling dust processing and the evolution of grain sizes in the ISM using the method of moments

    Science.gov (United States)

    Mattsson, Lars

    2016-11-01

    Interstellar dust grains do not have a single well-defined origin. Stars are demonstrably dust producers, but also efficient destroyers of cosmic dust. Dust destruction in the ISM is believed to be the result of SN shocks hitting the ambient ISM gas (and dust) and lead to an increased rate of ion sputtering, which reduces the dust mass. Grains located in cold molecular clouds can on the other hand grow by condensation, thus providing a replenishment mechanism or even a dominant channel of dust formation. In dense environments grains may coagulate and form large composite grains and aggregates and if grains collide with large enough energies they may be shattered, forming a range of smaller debris grains. The present paper presents a statistical modelling approach using the method of moments, which is computationally very inexpensive and may therefore be an attractive option when combining dust processing with, e.g., detailed simulations of interstellar gas dynamics. A solar-neighbourhood-like toy model of interstellar dust evolution is presented as an example.

  9. 解扰动非线性发展方程的Lie-B(a)cklund方法%A NEW APPROACH TO SOLVE PERTURBED NONLINEAR EVOLUTION EQUATIONS THROUGH LIE-BACKLUND SYMMETRY METHOD

    Institute of Scientific and Technical Information of China (English)

    牛晓花; 潘祖梁

    2006-01-01

    A new method based on Lie-B(a)cklund symmetry method to solve the perturbed nonlinear evolution equations is presented. New approximate solutions of perturbed nonlinear evolution equations stemming from the exact solutions of unperturbed equations are obtained.This method is a generalization of Burde's Lie point symmetry technique.

  10. A single-shot spatial chirp method for measuring initial AC conductivity evolution of femtosecond laser pulse excited warm dense matter

    Science.gov (United States)

    Chen, Z.; Hering, P.; Brown, S. B.; Curry, C.; Tsui, Y. Y.; Glenzer, S. H.

    2016-11-01

    To study the rapid evolution of AC conductivity from ultrafast laser excited warm dense matter (WDM), a spatial chirp single-shot method is developed utilizing a crossing angle pump-probe configuration. The pump beam is shaped individually in two spatial dimensions so that it can provide both sufficient laser intensity to excite the material to warm dense matter state and a uniform time window of up to 1 ps with sub-100 fs FWHM temporal resolution. Temporal evolution of AC conductivity in laser excited warm dense gold was also measured.

  11. Real-Time Simulation of Aeolian Sand Movement and Sand Ripple Evolution: A Method Based on the Physics of Blown Sand

    Institute of Scientific and Technical Information of China (English)

    Ning Wang; Bao-Gang Hu

    2012-01-01

    Simulation and visualization of aeolian sand movement and sand ripple evolution are a challenging subject.In this paper,we propose a physically based modeling and simulating method that can be used to synthesize sandy terrain in various patterns.Our method is based on the mechanical behavior of individual sand grains,which are widely studied in the physics of blown sand.We accounted significant mechanisms of sand transportation into the sand model,such as saltation,successive saltation and collapsing,while simplified the vegetation model and wind field model to make the simulation feasible and affordable.We implemented the proposed method on the programming graphics processing unit (GPU) to get real-time simulation and rendering.Finally,we proved that our method can reflect many characteristics of sand ripple evolution through several demonstrations.We also gave several synthesized desert scenes made from the simulated height field to display its significance on application.

  12. Development of an analytical method for the determination of arsenic in gasoline samples by hydride generation-graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Emilene M. [Universidade Federal do Pampa, Bage, RS (Brazil); Universidade Federal de Pelotas, Pelotas, RS (Brazil); Dessuy, Morgana B.; Boschetti, Wiliam [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 9500, 91501-970 Porto Alegre, RS (Brazil); Vale, Maria Goreti R., E-mail: mgrvale@ufrgs.br [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Ferreira, Sergio L.C. [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Instituto de Quimica, Universidade Federal da Bahia, Salvador, BA (Brazil); Welz, Bernhard [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil)

    2012-05-15

    The purpose of the present work was to optimize the conditions for the determination of arsenic in gasoline with hydride generation-graphite furnace atomic absorption spectrometry after acid digestion using a full two-level factorial design with center point. The arsine was generated in a batch system and collected in a graphite tube coated with 150 {mu}g Ir as a permanent modifier. The sample volume, the pre-reduction conditions, the temperature program and modifier mass were kept fixed for all experiments. The estimated main effects were: reducing agent concentration (negative effect), acid concentration (negative effect) and trapping temperature (positive effect). It was observed that there were interactions between the variables. Moreover, the curvature was significant, indicating that the best conditions were at the center point. The optimized parameters for arsine generation were 2.7 mol L{sup -1} hydrochloric acid and 1.6% (w/v) sodium tetrahydroborate. The optimized conditions to collect arsine in the graphite furnace were a trapping temperature of 250 Degree-Sign C and a collection time of 30 s. The limit of detection was 6.4 ng L{sup -1} and the characteristic mass was 24 pg. Two different systems for acid digestion were used: a digester block with cold finger and a microwave oven. The concentration of arsenic found with the proposed method was compared with that obtained using a detergentless microemulsion and direct graphite furnace determination. The results showed that the factorial design is a simple tool that allowed establishing the appropriate conditions for sample preparation and also helped in evaluating the interaction between the factors investigated. - Highlights: Black-Right-Pointing-Pointer We determined As in gasoline using hydride generation-graphite furnace AAS. Black-Right-Pointing-Pointer We compared three sample preparation procedures. Black-Right-Pointing-Pointer A multivariate approach was used to optimize the conditions. Black

  13. The Impact of Reconstruction Methods, Phylogenetic Uncertainty and Branch Lengths on Inference of Chromosome Number Evolution in American Daisies (Melampodium, Asteraceae)

    Science.gov (United States)

    McCann, Jamie; Stuessy, Tod F.; Villaseñor, Jose L.; Weiss-Schneeweiss, Hanna

    2016-01-01

    Chromosome number change (polyploidy and dysploidy) plays an important role in plant diversification and speciation. Investigating chromosome number evolution commonly entails ancestral state reconstruction performed within a phylogenetic framework, which is, however, prone to uncertainty, whose effects on evolutionary inferences are insufficiently understood. Using the chromosomally diverse plant genus Melampodium (Asteraceae) as model group, we assess the impact of reconstruction method (maximum parsimony, maximum likelihood, Bayesian methods), branch length model (phylograms versus chronograms) and phylogenetic uncertainty (topological and branch length uncertainty) on the inference of chromosome number evolution. We also address the suitability of the maximum clade credibility (MCC) tree as single representative topology for chromosome number reconstruction. Each of the listed factors causes considerable incongruence among chromosome number reconstructions. Discrepancies between inferences on the MCC tree from those made by integrating over a set of trees are moderate for ancestral chromosome numbers, but severe for the difference of chromosome gains and losses, a measure of the directionality of dysploidy. Therefore, reliance on single trees, such as the MCC tree, is strongly discouraged and model averaging, taking both phylogenetic and model uncertainty into account, is recommended. For studying chromosome number evolution, dedicated models implemented in the program ChromEvol and ordered maximum parsimony may be most appropriate. Chromosome number evolution in Melampodium follows a pattern of bidirectional dysploidy (starting from x = 11 to x = 9 and x = 14, respectively) with no prevailing direction. PMID:27611687

  14. [Prediction method of rural landscape pattern evolution based on life cycle: a case study of Jinjing Town, Hunan Province, China].

    Science.gov (United States)

    Ji, Xiang; Liu, Li-Ming; Li, Hong-Qing

    2014-11-01

    Taking Jinjing Town in Dongting Lake area as a case, this paper analyzed the evolution of rural landscape patterns by means of life cycle theory, simulated the evolution cycle curve, and calculated its evolution period, then combining CA-Markov model, a complete prediction model was built based on the rule of rural landscape change. The results showed that rural settlement and paddy landscapes of Jinjing Town would change most in 2020, with the rural settlement landscape increased to 1194.01 hm2 and paddy landscape greatly reduced to 3090.24 hm2. The quantitative and spatial prediction accuracies of the model were up to 99.3% and 96.4%, respectively, being more explicit than single CA-Markov model. The prediction model of rural landscape patterns change proposed in this paper would be helpful for rural landscape planning in future.

  15. Numerical simulation of strain localization and damage evolution in large plastic deformation using mixed finite element method

    Institute of Scientific and Technical Information of China (English)

    Zhanghua Chen; Jiajian Jin; Jiumei Xiao

    2004-01-01

    An investigation of computer simulation is presented to analyze the effects of strain localization and damage evolution in large plastic deformation. The simulation is carried out by using an elastic-plastic-damage coupling finite element program that is developed based on the concept of mixed interpolation of displacement/pressure. This program has been incorporated into a damage mechanics model as well as the corresponding damage criterion. To illustrate the performance of the proposed approach, a typical strain localization problem has been simulated. The results show that the proposed approach is of good capability to capture strain localization and predict the damage evolution.

  16. Effect of Current Frequency on Droplet Evolution During Magnetic-Field-Controlled Electroslag Remelting Process Via Visualization Method

    Science.gov (United States)

    Wang, Huai; Zhong, Yunbo; Li, Qiang; Fang, Yipeng; Ren, Weili; Lei, Zuosheng; Ren, Zhongming

    2017-02-01

    A transparent physical model was set up to investigate the influence of the remelting current frequencies on droplet evolution during the magnetic-field-controlled electroslag remelting process. Physical simulation experiments were done under the remelting current of 8 A with frequencies ranging from 10 to 500 Hz, and a transverse static magnetic field (TSMF) of 0.7 T was superimposed simultaneously. The high-speed camera was used to record the evolution behavior of the droplet. Representative processes of formation and detachment of the droplets were observed under different conditions. The results showed that there was little influence of the current frequencies on the evolution behavior of the droplet without the external magnetic field. Nevertheless, if a TSMF was introduced, the liquid droplet's neck would be smashed into a lot of smaller droplets when the remelting current frequencies were lower than 100 Hz, while the smashing effect disappeared when the frequencies were higher than 100 Hz. The mechanism of the smashing effect was discussed. Statistical work was done to obtain the quantitative data to give a clear result revealing the influence of the remelting current frequencies on droplet evolution. The decrease in the diameter of the liquid droplets would remarkably increase the interface area and shorten the migrating distance of the inclusions in the droplets, which meant that a higher purifying efficiency could be expected.

  17. Evolution of heavy quark distribution function on quark-gluon plasma: Using the Iterative Laplace Transform Method

    Directory of Open Access Journals (Sweden)

    Pari Sharareh Mehrabi

    2016-01-01

    Full Text Available The “Laplace Transform Method” is used to solve the Fokker-Plank equation for finding the time evolution of the heavy quarks distribution functions such as charm and bottom in quark gluon plasma. These solutions will lead us to calculation of nuclear suppression factor RAA. The results have good agreement with available experiment data from the PHENIX collaboration.

  18. Practical splitting methods for the adaptive integration of nonlinear evolution equations. Part I: Construction of optimized schemes and pairs of schemes

    KAUST Repository

    Auzinger, Winfried

    2016-07-28

    We present a number of new contributions to the topic of constructing efficient higher-order splitting methods for the numerical integration of evolution equations. Particular schemes are constructed via setup and solution of polynomial systems for the splitting coefficients. To this end we use and modify a recent approach for generating these systems for a large class of splittings. In particular, various types of pairs of schemes intended for use in adaptive integrators are constructed.

  19. 一种自适应网络舆情演化建模方法%Adaptive Evolution Modeling Method of Internet Public Opinions

    Institute of Scientific and Technical Information of China (English)

    周耀明; 李弼程

    2013-01-01

    The existing short-term trend forecasting method ignores the variability of statistical properties of Internet public opinions' evolution, which leads to a blind model selection, and the poor forecasting performance. Therefore, an adaptive evolution modeling method of Internet public opinions (AEMIPO) is presented. Firstly, the method tracks the statistical characteristics of the process of Internet public opinions' evolution dynamically, such as smoothness, periodicity and self-similarity. Then, by selecting ARM A, ARIMA, SARIMA and FARIMA, an alternative model bank is constructed. Finally, by making model selection rules, an appropriate model is selected to model and forecast the evolution process adaptively. Experimental results show that compared with the existing methods, AEMIPO has higher forecasting accuracy and stability, and the method is more suitable for short-term modeling and forecasting of Internet public opinions' evolution trend.%针对短期趋势预测方法忽略演化过程统计特性的动态变化性,致使模型选择盲目、预测效果较差的问题,本文提出一种自适应网络舆情演化建模方法(AEMIPO).首先,动态跟踪网络舆情演化过程的平稳性、周期性和自相似性等统计特性;其次,选取能够描述上述统计特性的ARMA,ARIMA,SARIMA,FARIMA模型构建备选模型库;最后,通过制定模型选择规则,从备选模型库中选择合适的模型对当前时刻的演化过程进行自适应建模,并预测其演化趋势.实验表明,与现有方法相比,AEMIPO具有更高的预测精度与更好的预测稳定性,更适合对网络舆情演化过程进行短期建模及趋势预测.

  20. Quaternary volcanic-sedimentary sequences and evolution of the Llancanelo Lake region (Southern Mendoza, Western Argentina) evidenced from geoelectric methods

    Science.gov (United States)

    de la Vega, Matias; Lopez, Ernesto; Osella, Ana; Rovere, Elizabeth I.; Violante, Roberto A.

    2012-12-01

    Llancanelo Lake region (Southern Mendoza Province, Western Argentina) is a key area for investigating the regional evolution of a tectonic basin affected by intense arc- and back-arc volcanism. However, the lack of enough outcrops makes it difficult to perform such reconstructions. In order to solve this problem, and with the aim of depicting the subsurface stratigraphy, 22 geoelectric surveys reaching more than 100 m depth were performed. The applied methodology, that combined geoelectrical measurements and field observations, is a continuation of previous works carried out in the region, and allowed for the first time to establish a near-surface stratigraphy that records the last evolutive stages of the lake. The studied region is mainly composed of Quaternary volcanic and sedimentary sequences. Four units were recognized on the basis of the geoelectrical differences (resistivity signal) supported by field observations where they crop out. Two of them have very high resistivity and are composed of basaltic lava flows, hence indicating the volcanic influence in the region. The other two have very low resistivity and correspond to sedimentary deposits, being the uppermost one composed of lacustrine sediments. The units were named according to the well-known stratigraphic scheme valid for the region. The studied stratigraphic sequence encompasses the time-span from the Pliocene to the present, and its interpretation allowed to establish the main evolutive stages, characterized by a complex interaction among tectonic, volcanic and climatic factors. The damming of the lake by basaltic flows and the consequent reduction of the lake's extension at times of intensive volcanic activity is one of the most significant events in its evolution.

  1. Continuum representation of systems of dislocation lines: A general method for deriving closed-form evolution equations

    Science.gov (United States)

    Monavari, Mehran; Sandfeld, Stefan; Zaiser, Michael

    2016-10-01

    Plasticity is governed by the evolution of, in general anisotropic, systems of dislocations. We seek to faithfully represent this evolution in terms of density-like variables which average over the discrete dislocation microstructure. Starting from T. Hochrainer's continuum theory of dislocations (CDD) (Hochrainer, 2015), we introduce a methodology based on the 'Maximum Information Entropy Principle' (MIEP) for deriving closed-form evolution equations for dislocation density measures of different order. These equations provide an optimum representation of the kinematic properties of systems of curved and connected dislocation lines with the information contained in a given set of density measures. The performance of the derived equations is benchmarked against other models proposed in the literature, using discrete dislocation dynamics simulations as a reference. As a benchmark problem we study dislocations moving in a highly heterogeneous, persistent-slip-band like geometry. We demonstrate that excellent agreement with discrete simulations can be obtained in terms of a very small number of averaged dislocation fields containing information about the edge and screw components of the total and excess (geometrically necessary) dislocation densities. From these the full dislocation orientation distribution which emerges as dislocations move through a channel-wall structure can be faithfully reconstructed.

  2. Capture and evolution of dust in planetary mean-motion resonances: a fast, semi-analytic method for generating resonantly trapped disk images

    CERN Document Server

    Shannon, Andrew; Wyatt, Mark

    2015-01-01

    Dust grains migrating under Poynting-Robertson drag may be trapped in mean-motion resonances with planets. Such resonantly trapped grains are observed in the solar system. In extrasolar systems, the exozodiacal light produced by dust grains is expected to be a major obstacle to future missions attempting to directly image terrestrial planets. The patterns made by resonantly trapped dust, however, can be used to infer the presence of planets, and the properties of those planets, if the capture and evolution of the grains can be modelled. This has been done with N-body methods, but such methods are computationally expensive, limiting their usefulness when considering large, slowly evolving grains, and for extrasolar systems with unknown planets and parent bodies, where the possible parameter space for investigation is large. In this work, we present a semi-analytic method for calculating the capture and evolution of dust grains in resonance, which can be orders of magnitude faster than N-body methods. We calibr...

  3. Microstructure evolution and thixoforming behavior of 7075 aluminum alloy in the semi-solid state prepared by RAP method

    Science.gov (United States)

    Fu, Jin-long; Wang, Kai-kun; Li, Xiao-wei; Zhang, Hai-kuan

    2016-12-01

    The effects of isothermal treatments on the microstructural evolution and coarsening rate of semi-solid 7075 aluminum alloy produced via the recrystallization and partial remelting (RAP) process were investigated. Samples of 7075 aluminum alloy were subjected to cold extrusion, and semi-solid treatment was carried out for 5-30 min at temperatures ranging from 580 to 605°C. A backward-extrusion experiment was conducted to investigate liquid segregation during the thixoforming process. The results revealed that obvious grain coarsening and spheroidization occurred during prolonged isothermal treatments. In addition, higher soaking temperatures promoted the spheroidization and coarsening process because of the increased liquid fraction and the melting of second phases. Segregation of the liquid phase caused by the difference in fluidity between the liquid and the solid phases was observed in different regions of the thixoformed specimens.

  4. Simulation of microstructural evolution in directional solidification of Ti-45at.%Al alloy using cellular automaton method

    Directory of Open Access Journals (Sweden)

    Wang Kuangfei

    2010-02-01

    Full Text Available The microstructural evolution of Ti-45 at.%Al alloy during directional solidification was simulated by applying a solute diffusion controlled solidification model. The obtained results have shown that under high thermal gradients the stable primary spacing can be adjusted via branching or competitive growth. For dendritic structures formed under a high thermal gradient, the secondary dendrite arms are developed not very well in many cases due to the branching mechanism under a constrained dendritic growth condition. Furthermore, it has been observed that, with increasing pulling velocity, there exists a cell/dendrite transition region consisting of cells and dendrites, which varies with the thermal gradient in a contradicting way, i.e. increase of the thermal gradient leading to the decrease of the range of the transition region. The simulations agree reasonably well with experiment results.

  5. A numerical method based on the Fourier-Fourier transform approach for modeling 1-D electron plasma evolution. [in earth bow shock region

    Science.gov (United States)

    Klimas, A. J.

    1983-01-01

    A numerical method is presented for studying one-dimensional electron plasma evolution under typical interplanetary conditions. The method applies the Fourier-Fourier transform approach to a plasma model that is a generalization of the electrostatic Vlasov-Poisson system of equations. Conservation laws that are modified to include the plasma model generalization and also the boundary effects of nonperiodic solutions are given. A new conservation law for entropy in the transformed space is then introduced. These conservation laws are used to verify the numerical solutions. A discretization error analysis is presented. Two numerical instabilities and the methods used for their suppression are treated. It is shown that in interplanetary plasma conditions, the bump-on-tail instability produces significant excitation of plasma oscillations at the Bohm-Gross frequency and its second harmonic. An explanation of the second harmonic excitation is given in terms of wave-wave coupling during the growth phase of the instability.

  6. Cross-splicing method for compensating fiber birefringence in polarization-maintaining fiber ring laser mode locked by nonlinear polarization evolution.

    Science.gov (United States)

    Wang, Yunzheng; Zhang, Liqiang; Zhuo, Zhuang; Guo, Songzhen

    2016-07-20

    We propose a cross-splicing method, for the first time to our knowledge, to compensate the effect of fiber birefringence in a polarization-maintaining fiber ring laser mode locked by nonlinear polarization evolution. This method has been investigated numerically and experimentally. The results indicate that stable mode-locking pulses can be obtained in the cavity with this method; otherwise, no mode-locking states are achieved. The design processes of the laser cavity are presented. Pulses with single pulse energy of 2.1 nJ are generated at pump power of 460 mW. The spectral bandwidth and pulse duration are 17.5 nm and 11.7 ps, respectively. The tunability of the laser is also studied. The central wavelength can be tuned from 1023.2 to 1045.9 nm.

  7. Hydrogen evolution reaction catalyst

    Science.gov (United States)

    Subbaraman, Ram; Stamenkovic, Vojislav; Markovic, Nenad; Tripkovic, Dusan

    2016-02-09

    Systems and methods for a hydrogen evolution reaction catalyst are provided. Electrode material includes a plurality of clusters. The electrode exhibits bifunctionality with respect to the hydrogen evolution reaction. The electrode with clusters exhibits improved performance with respect to the intrinsic material of the electrode absent the clusters.

  8. 声振检测方法的发展%Evolution of the Acoustic Impact Testing Method

    Institute of Scientific and Technical Information of China (English)

    邬冠华; 林俊明; 任吉林; 周昌智

    2011-01-01

    依据激励方式的不同,分别从敲击检测和声阻检测方法两个方面对声振检测方法进行了介绍.敲击检测方法主要分整体振动检测法(或车轮敲击法)和局部振动检测法(或硬币敲击法),声阻检测法主要分机械阻抗法和局部共振检测法.声振检测方法尽管很早以前就已经出现了,但至今主要还停留在经验性的应用层面.对各种声振检测方法的基本原理及其发展作简要论述,希望起到抛砖引玉的作用,吸引业界关注该方法发展和应用的同仁共同来推进它的技术进步.%The acoustic impact testing method is presented with two different excitation methods: the tap testing method and the acoustic impedance testing method.The tap testing method includes the whole vibration testing (wheel-tap test) method and the local vibration testing method( coin-tap test), and the acoustic impedance method has the mechanical impedance method and the local resonance testing method.Though the acoustic impact testing method has a long history in testing activities, most concerns of this method are only restricted in its experiential applications.Here, the principals and their developments of several branches of the acoustic impact testing method are covered, with the main purpose to improve this old but effective method with the help of the people who concern its development and applications.

  9. Evolution of antioxidants in dietary fiber powder produced from white cabbage outer leaves: effects of blanching and drying methods.

    Science.gov (United States)

    Tanongkankit, Yardfon; Chiewchan, Naphaporn; Devahastin, Sakamon

    2015-04-01

    White cabbage outer leaves, which are usually discarded both during industrial processing and selling in a consumer market, have proven to be a good source of dietary fiber (DF) as well as antioxidants and can be effectively transformed into functional DF powder. In the past, however, only hot air drying was used to prepare DF powder from cabbage outer leaves although it is well recognized that this drying technique could lead to much quality degradation of a dried product. This work was therefore aimed at studying the evolution of selected important antioxidants, e.g., phenolic compounds and vitamin C, in white cabbage outer leaves during vacuum drying at 60, 70 and 80 °C. The effect of pretreatment viz. steam blanching was also evaluated. The results showed that there were losses of antioxidants during steam blanching; vacuum dried blanched leaves nevertheless contained higher antioxidant contents and activity than dried unblanched leaves. Losses of antioxidants during vacuum drying were also noted to be less than those during hot air drying. Overall, the results showed that there were no differences in the antioxidants retention among all the tested conditions performed in this study. Therefore, the most suitable condition for the production of antioxidant DF powder from cabbage outer leaves is vacuum drying at 80 °C as this condition requires the minimum specific energy consumption.

  10. Stability of the IMEX Methods, CNLF and BDF2-AB2, for Uncoupling Systems of Evolution Equations

    Science.gov (United States)

    2011-02-01

    Implicit-Explicit linear multistep methods, Tech. rep., Centrum Wiskunde and Informatica (CWI) (1996). [14] W. Hundsdorfer, J. Verwer, Numerical...component splitting for the Crank-Nicolson Leap- Frog integration method, Tech. rep., Centrum Wiskunde and Informatica (CWI) (2009). [23] J. Verwer

  11. Realization method of RS flip-flop evolution based on HDL simulator%基于HDL仿真的RS触发器演化实现方法

    Institute of Scientific and Technical Information of China (English)

    娄建安; 崔新风; 李丹丹; 张之武; 李川涛

    2011-01-01

    It is diffcult to implement extrinsic evolution for sequential logic circuit because of feedback loop. To solve this problem, HDL simulator is used to evaluate the fitness of circuit, then to realize the evolution of sequential logic circuit.Gate level circuit model with feedback is build, so the one-to-one corresponding relationship between the connectivity and the mathematical encoding of the circuit is established. The VHDL code file is generated according to the circuit encoding,which is simulated and evaluated by calling ModelSim software. Through simulation the individual sufficientcy is obtained to guide the next evolutior. The experiment result from simulation shows that this method realizes the autonomic running completely of sequential logic circuit evolution design, and has good versatility.%为解决时序电路由于存在反馈环很难实现外部演化的问题,提出了利用HDL仿真器对电路进行适应度评估,进而实现时序电路演化的方法.通过建立带反馈线的门级电路模型,将电路连接形式与电路的数学编码一一对应起来;根据电路编码写出相应的VHDL代码文件,调用ModelSim仿真软件对其进行仿真评估,得出个体适应度指导下一步演化进行.仿真实验结果表明,该方法实现了时序电路演化设计的完全自主运行,具有较好的通用性.

  12. Monitoring of the Polar Stratospheric Clouds formation and evolution in Antarctica in August 2007 during IPY with the MATCH method applied to lidar data

    Science.gov (United States)

    Montoux, Nadege; David, Christine; Klekociuk, Andrew; Pitts, Michael; di Liberto, Luca; Snels, Marcel; Jumelet, Julien; Bekki, Slimane; Larsen, Niels

    2010-05-01

    The project ORACLE-O3 ("Ozone layer and UV RAdiation in a changing CLimate Evaluated during IPY") is one of the coordinated international proposals selected for the International Polar Year (IPY). As part of this global project, LOLITA-PSC ("Lagrangian Observations with Lidar Investigations and Trajectories in Antarctica and Arctic, of PSC") is devoted to Polar Stratospheric Clouds (PSC) studies. Indeed, understanding the formation and evolution of PSC is an important issue to quantify the impact of climate changes on their frequency of formation and, further, on chlorine activation and subsequent ozone depletion. In this framework, three lidar stations performed PSC observations in Antarctica during the 2006, 2007, and 2008 winters: Davis (68.58°S, 77.97°E), McMurdo (77.86°S, 166.48°E) and Dumont D'Urville (66.67°S, 140.01°E). The data are completed with the lidar data from CALIOP ("Cloud-Aerosol Lidar with Orthogonal Polarization") onboard the CALIPSO ("Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation") satellite. Lagrangian trajectory calculations are used to identify air masses with PSCs sounded by several ground-based lidar stations with the same method, called MATCH, applied for the first time in Arctic to study the ozone depletion with radiosoundings. The evolution of the optical properties of the PSCs and thus the type of PSCs formed (supercooled ternary solution, nitric acid trihydrate particles or ice particles) could thus be linked to the thermodynamical evolution of the air mass deduced from the trajectories. A modeling with the microphysical model of the Danish Meteorological Institute allows assessing our ability to predict PSCs for various environmental conditions. Indeed, from pressure and temperature evolution, the model allows retrieving the types of particles formed as well as their mean radii, their concentrations and could also simulate the lidar signals. In a first step, a case in August 2007 around 17-18 km, involving

  13. Thought Evolution

    Directory of Open Access Journals (Sweden)

    Shadrikov V.D.

    2015-08-01

    Full Text Available The thought evolution is studied by historical reconstruction method that is based on the propositions of the theory of culturalhistorical determination of the psyche development, and the data of the morphological analysis and child development, and the conception of the psyche neuroontogenesis. The grounds for advisability of protothinking are presented. The protothinking is understood as the use of objective thought in cases of awareness absence. It is shown that protothinking is a form of transition from animal thinking to human speech. The particular attention is paid to the process of the word producing and thought generation in that process. The conditions of word producing as cooccurring acoustic pattern served for though expression are discussed. It is emphasized that a word is produced by a particular person. The historical development of the language and the specificity of this development are pointed out

  14. Community Evolution

    CERN Document Server

    Bródka, Piotr; Kazienko, Przemysław

    2016-01-01

    The continuous interest in the social network area contributes to the fast development of this field. The new possibilities of obtaining and storing data facilitate deeper analysis of the entire social network, extracted social groups and single individuals as well. One of the most interesting research topic is the network dynamics and dynamics of social groups in particular, it means analysis of group evolution over time. It is the natural step forward after social community extraction. Having communities extracted, appropriate knowledge and methods for dynamic analysis may be applied in order to identify changes as well as to predict the future of all or some selected groups. Furthermore, knowing the most probably change of a given group some additional steps may be performed in order to change this predicted future according to specific needs. Such ability would be a powerful tool in the hands of human resource managers, personnel recruitment, marketing, telecommunication companies, etc.

  15. A DNA sequence evolution analysis generalized by simulation and the markov chain monte carlo method implicates strand slippage in a majority of insertions and deletions.

    Science.gov (United States)

    Nishizawa, Manami; Nishizawa, Kazuhisa

    2002-12-01

    To study the mechanisms for local evolutionary changes in DNA sequences involving slippage-type insertions and deletions, an alignment approach is explored that can consider the posterior probabilities of alignment models. Various patterns of insertion and deletion that can link the ancestor and descendant sequences are proposed and evaluated by simulation and compared by the Markov chain Monte Carlo (MCMC) method. Analyses of pseudogenes reveal that the introduction of the parameters that control the probability of slippage-type events markedly augments the probability of the observed sequence evolution, arguing that a cryptic involvement of slippage occurrences is manifested as insertions and deletions of short nucleotide segments. Strikingly, approximately 80% of insertions in human pseudogenes and approximately 50% of insertions in murids pseudogenes are likely to be caused by the slippage-mediated process, as represented by BC in ABCD --> ABCBCD. We suggest that, in both human and murids, even very short repetitive motifs, such as CAGCAG, CACACA, and CCCC, have approximately 10- to 15-fold susceptibility to insertions and deletions, compared to nonrepetitive sequences. Our protocol, namely, indel-MCMC, thus seems to be a reasonable approach for statistical analyses of the early phase of microsatellite evolution.

  16. Using THz Spectroscopy, Evolutionary Network Analysis Methods, and MD Simulation to Map the Evolution of Allosteric Communication Pathways in c-Type Lysozymes.

    Science.gov (United States)

    Woods, Kristina N; Pfeffer, Juergen

    2016-01-01

    It is now widely accepted that protein function is intimately tied with the navigation of energy landscapes. In this framework, a protein sequence is not described by a distinct structure but rather by an ensemble of conformations. And it is through this ensemble that evolution is able to modify a protein's function by altering its landscape. Hence, the evolution of protein functions involves selective pressures that adjust the sampling of the conformational states. In this work, we focus on elucidating the evolutionary pathway that shaped the function of individual proteins that make-up the mammalian c-type lysozyme subfamily. Using both experimental and computational methods, we map out specific intermolecular interactions that direct the sampling of conformational states and accordingly, also underlie shifts in the landscape that are directly connected with the formation of novel protein functions. By contrasting three representative proteins in the family we identify molecular mechanisms that are associated with the selectivity of enhanced antimicrobial properties and consequently, divergent protein function. Namely, we link the extent of localized fluctuations involving the loop separating helices A and B with shifts in the equilibrium of the ensemble of conformational states that mediate interdomain coupling and concurrently moderate substrate binding affinity. This work reveals unique insights into the molecular level mechanisms that promote the progression of interactions that connect the immune response to infection with the nutritional properties of lactation, while also providing a deeper understanding about how evolving energy landscapes may define present-day protein function.

  17. Evolution of ossification sequences in salamanders and urodele origins assessed through event-pairing and new methods.

    Science.gov (United States)

    Germain, Damien; Laurin, Michel

    2009-01-01

    Ossification sequences of the skull in extant Urodela and in Permo-Carboniferous Branchiosauridae have already been used to study the origin of lissamphibians. But most of these studies did not consider some recent methods developed to analyze the developmental sequences within a phylogenetic framework. Here, we analyze the ossification sequences of 24 cranial bones of 23 extant species of salamanders using the event-pairing method. This reveals new developmental synapomorphies for several extant salamander taxa and ancestral sequences for Urodela under four alternative reference phylogenies. An analysis with the 12 bones for which ossification sequence data are available in urodeles and in the branchiosaurid Apateon is also performed in order to compare the ancestral condition of the crown-group of Urodela to the sequence of Apateon. This reveals far more incompatibilities than previously suggested. The similarities observed between some extant salamanders and branchiosaurids may result from extensive homoplasy, as the extreme variation observed in extant Urodela suggests, or be plesiomorphic, as the conservation of some ossification patterns observed in other remotely related vertebrates like actinopterygians suggests. We propose a new, simpler method based on squared-change optimization to estimate the relative timing of ossification of various bones of hypothetical ancestors, and use independent-contrasts analysis to estimate the confidence intervals around these times. Our results show that the uncertainty of the ancestral ossification sequence of Urodela is much greater than event-pairing suggests. The developmental data do not allow to conclude that branchiosaurids are closely related to salamanders and their limited taxonomic distribution in Paleozoic taxa precludes testing hypotheses about lissamphibian origins. This is true regardless of the analytical method used (event-pairing or our new method based on squared-change parsimony). Simulations show that

  18. Fermi surface evolution and d-wave superconductivity in CeCoIn5: Analysis based on LDA+DMFT method

    Science.gov (United States)

    Nomoto, Takuya; Ikeda, Hiroaki

    2014-09-01

    Based on the advanced first-principles theoretical approach, we investigate the superconducting gap structure and the pairing glue in the heavy-fermion superconductor CeCoIn5. Unexpectedly, the nesting function in the original GGA-based band structure, which is considered to be consistent with the dHvA measurement, shows a Q structure incompatible with experimental observations. Instead we find the importance of the temperature-dependent Fermi surface evolution driven by electron correlations, which has been calculated by the DMFT method. Considering this effect, we obtain reasonable antiferromagnetic correlation, which can also induce the expected d-wave superconductivity. The system encounters the superconducting transition, before a part of the Fermi surface is formed. Similar effects can be expected in generic heavy-fermion superconductors.

  19. New Traveling Wave Solutions by the Extended Generalized Riccati Equation Mapping Method of the (2+1-Dimensional Evolution Equation

    Directory of Open Access Journals (Sweden)

    Hasibun Naher

    2012-01-01

    Full Text Available The generalized Riccati equation mapping is extended with the basic (G′/G-expansion method which is powerful and straightforward mathematical tool for solving nonlinear partial differential equations. In this paper, we construct twenty-seven traveling wave solutions for the (2+1-dimensional modified Zakharov-Kuznetsov equation by applying this method. Further, the auxiliary equation G′(η=w+uG(η+vG2(η is executed with arbitrary constant coefficients and called the generalized Riccati equation. The obtained solutions including solitons and periodic solutions are illustrated through the hyperbolic functions, the trigonometric functions, and the rational functions. In addition, it is worth declaring that one of our solutions is identical for special case with already established result which verifies our other solutions. Moreover, some of obtained solutions are depicted in the figures with the aid of Maple.

  20. Bastion Classification: Evolution of Experience Mandates Caution when Considering Using Class as Predictor for Method of Temporary Vascular Control

    Science.gov (United States)

    2013-01-01

    D. The management of open fractures. Journal of Bone and Joint Surgery 1990;72:299–304. Arash Moghaddam-Alvandi* Department of Orthopaedics, Trauma ...Mannheim, Department of Trauma Surgery, Bassermannstr. 1, 68165 Mannheim, Germany Kathrin Hammer Klinik für Unfallchirurgie und Orthopädie...associated injuries according to the ABCD component of the system). Our current approach for determination of method of obtaining vascular control is

  1. CrystalMoM: a tool for modeling the evolution of Crystals Size Distributions in magmas with the Method of Moments

    Science.gov (United States)

    Colucci, Simone; de'Michieli Vitturi, Mattia; Landi, Patrizia

    2016-04-01

    It is well known that nucleation and growth of crystals play a fundamental role in controlling magma ascent dynamics and eruptive behavior. Size- and shape-distribution of crystal populations can affect mixture viscosity, causing, potentially, transitions between effusive and explosive eruptions. Furthermore, volcanic samples are usually characterized in terms of Crystal Size Distribution (CSD), which provide a valuable insight into the physical processes that led to the observed distributions. For example, a large average size can be representative of a slow magma ascent, and a bimodal CSD may indicate two events of nucleation, determined by two degassing events within the conduit. The Method of Moments (MoM), well established in the field of chemical engineering, represents a mesoscopic modeling approach that rigorously tracks the polydispersity by considering the evolution in time and space of integral parameters characterizing the distribution, the moments, by solving their transport differential-integral equations. One important advantage of this approach is that the moments of the distribution correspond to quantities that have meaningful physical interpretations and are directly measurable in natural eruptive products, as well as in experimental samples. For example, when the CSD is defined by the number of particles of size D per unit volume of the magmatic mixture, the zeroth moment gives the total number of crystals, the third moment gives the crystal volume fraction in the magmatic mixture and ratios between successive moments provide different ways to evaluate average crystal length. Tracking these quantities, instead of volume fraction only, will allow using, for example, more accurate viscosity models in numerical code for magma ascent. Here we adopted, for the first time, a quadrature based method of moments to track the temporal evolution of CSD in a magmatic mixture and we verified and calibrated the model again experimental data. We also show how

  2. A STUDY ON NUMERICAL METHOD OF NAVIER-STOKES EQUATION AND NON-LINEAR EVOLUTION OF THE COHERENT STRUCTURES IN A LAMINAR BOUNDARY LAYER

    Institute of Scientific and Technical Information of China (English)

    LU Chang-gen; CAO Wei-dong; QIAN Jian-hua

    2006-01-01

    A new method for direct numerical simulation of incompressible Navier-Stokes equations is studied in the paper. The compact finite difference and the non-linear terms upwind compact finite difference schemes on non-uniform meshes in x and y directions are developed respectively. With the Fourier spectral expansion in the spanwise direction, three-dimensional N-S equation are converted to a system of two-dimensional equations. The third-order mixed explicit-implicit scheme is employed for time integration. The treatment of the three-dimensional non-reflecting outflow boundary conditions is presented, which is important for the numerical simulations of the problem of transition in boundary layers, jets, and mixing layer. The numerical results indicate that high accuracy, stabilization and efficiency are achieved by the proposed numerical method. In addition, a theory model for the coherent structure in a laminar boundary layer is also proposed, based on which the numerical method is implemented to the non-linear evolution of coherent structure. It is found that the numerical results of the distribution of Reynolds stress, the formation of high shear layer, and the event of ejection and sweeping, match well with the observed characteristics of the coherent structures in a turbulence boundary layer.

  3. Evolution of quantitative methods for the study and management of avian populations: on the importance of individual contributions

    Directory of Open Access Journals (Sweden)

    Nichols, J. D.

    2004-01-01

    Full Text Available The EURING meetings and the scientists who have attended them have contributed substantially to the growth of knowledge in the field of estimating parameters of animal populations. The contributions of David R. Anderson to process modeling, parameter estimation and decision analysis are briefly reviewed. Metrics are considered for assessing individual contributions to a field of inquiry, and it is concluded that Anderson's contributions have been substantial. Important characteristics of Anderson and his career are the ability to identify and focus on important topics, the premium placed on dissemination of new methods to prospective users, the ability to assemble teams of complementary researchers, and the innovation and vision that characterized so much of his work. The paper concludes with a list of interesting current research topics for consideration by EURING participants

  4. Modelling dust processing and the evolution of grain sizes in the ISM using the method of moments

    CERN Document Server

    Mattsson, Lars

    2016-01-01

    Interstellar dust grains do not have a single well-defined origin. Stars are demonstrably dust producers, but also efficient destroyers of cosmic dust. Dust destruction in the ISM is believed to be the result of SN shocks hitting the ambient ISM gas (and dust) and lead to an increased rate of ion sputtering, which reduces the dust mass. Grains located in cold molecular clouds can on the other hand grow by condensation, thus providing a replenishment mechanism or even a dominant channel of dust formation. In dense environments grains may coagulate and form large composite grains and aggregates and if grains collide with large enough energies they may be shattered, forming a range of smaller debris grains. The present paper presents a statistical modelling approach using the method of moments, which is computationally very inexpensive and may therefore be an attractive option when combining dust processing with, e.g., detailed simulations of interstellar gas dynamics. A solar-neighbourhood-like toy model of int...

  5. A Preliminary Study on the Calculating Method for the Evolution of Siltation and Erosion of Tidal Flat Based on GIS

    Institute of Scientific and Technical Information of China (English)

    DU Jinglong; GAO Ang; YANG Shilun; ZHANG Wenxiang; ZHAO Huayun; LI Peng

    2005-01-01

    The estuary and coast is an area where the land and the sea interact and a place in which human beings frequently move about so that understanding and controlling the change and development modes of the coastal landform plays a vital part in exploiting and protecting coastal resources. A model is the generalization and abstraction of objective things. This paper summarizes four methods for the landform development of the tidal shore and underwater delta, mainly discusses the model's structural elements, and presents their specific application on the basis of the authors' case study. With the application of the profile model, the dynamic change of coastal landform can be clearly seen by contrasting the different profiles of different years.Through the shrinking, expanding and transformation of the isobath, plane model is used to study the macro-change of the shoal and the coastal landform. Speed model is an efficient means to analyze the trend of erosion and deposition and the local change in a great area of the sea. Statistical survey model is a static analysis, which can be used to establish the relationship between the erosion and deposition of the shoal and the altitude and slope of survey spot.

  6. Self-Etching-Induced Morphological Evolution of ZnO Microrods Grown on FTO Glass by Hydrothermal Method

    Science.gov (United States)

    Hsu, Wen-Dung; Tsai, Jenn-Kai; Meen, Teen-Hang; Wu, Tian-Chiuan; He, Yan-Kuan; Lai, Yu-Da

    2015-10-01

    In this research, the zinc oxide (ZnO) microrods were grown by hydrothermal method on fluorine-doped tin oxide (FTO) glass functionalized by self-assembled monolayer of octadecyltrimethoxysilane (ODS; CH3(CH2)17Si(OCH3)3). The sharp-tip or polygonal shape with specific facets at the top end of ZnO microrods can be obtained by post retention at low temperature. The morphologies were characterized by the field-emission scanning electron microscope (FESEM) and transmission electron microscopy (TEM). The results confirm that the morphology change at the top end is due to self-etching. The mechanism responsible for the formation of various top-end morphologies was proposed. The specific facets that left after 6-h retention were identified. The room-temperature micro-photoluminescence spectra showed a strong ultraviolet emission at 387 nm, and a broad emission at a range of from 500 to 700 nm. The morphology change also influences the photoluminescence (PL) spectra. A satellite peak in the UV emission spectra was observed. The peak may be attributed to the morphology effect of the microrods.

  7. Dual phase evolution

    CERN Document Server

    Green, David G; Abbass, Hussein A

    2014-01-01

    This book explains how dual phase evolution operates in all these settings and provides a detailed treatment of the subject. The authors discuss the theoretical foundations for the theory, how it relates to other phase transition phenomena and its advantages in evolutionary computation and complex adaptive systems. The book provides methods and techniques to use this concept for problem solving. Dual phase evolution concerns systems that evolve via repeated phase shifts in the connectivity of their elements. It occurs in vast range of settings, including natural systems (species evolution, landscape ecology, geomorphology), socio-economic systems (social networks) and in artificial systems (annealing, evolutionary computing).

  8. Schumpeter's Evolution

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    reworking of his basic theory of economic evolution in Development from 1934, and this reworking was continued in Cycles from 1939. Here Schumpeter also tried to handle the statistical and historical evidence on the waveform evolution of the capitalist economy. Capitalism from 1942 modified the model...

  9. Evolution of N/O Abundance Ratios and Ionization Parameters from z~0 to 2 Investigated by the Direct Temperature Method

    CERN Document Server

    Kojima, Takashi; Nakajima, Kimihiko; Shibuya, Takatoshi; Harikane, Yuichi; Ono, Yoshiaki

    2016-01-01

    We present N/O abundance ratios, ionization parameters $q_{\\rm ion}$, and oxygen abundance O/H of eleven $z\\sim 2$ galaxies determined by the direct temperature $T_{\\rm e}$ method with [OIII] $\\lambda$4363 and OIII] $\\lambda$1665 lines, and investigate galaxy evolution from $z\\sim 0$ to $2$ in conjunction with $T_{\\rm e}$-method measurements of 208,529 SDSS galaxies and 9 green pea galaxies (GPs). We identify that three out of our eleven $z\\sim 2$ galaxies clearly fall beyond the local average of N/O-O/H and N/O-stellar mass ($M_{\\star}$) relations, while the rest of the $z\\sim 2$ galaxies have N/O ratios comparable with $z\\sim 0$ galaxies. The eleven $z\\sim 2$ galaxies place the upper limit of N/O ratio $\\log ({\\rm N/O})\\le -1.28$ on average, suggesting that the N/O ratio evolves, if any, by $<0.15$ dex. We find that two of our $z\\sim 2$ galaxies with the significant BPT offsets show both N/O ratio and $q_{\\rm ion}$ about 0.4-dex higher than the local average, while there exist $z\\sim 0$ green-pea galaxie...

  10. Biodegradability of Poly-3-hydroxybutyrate/Bacterial Cellulose Composites under Aerobic Conditions, Measured via Evolution of Carbon Dioxide and Spectroscopic and Diffraction Methods.

    Science.gov (United States)

    Ruka, Dianne R; Sangwan, Parveen; Garvey, Christopher J; Simon, George P; Dean, Katherine M

    2015-08-18

    Poly-3-hydroxybutyrate (PHB) and bacterial cellulose (BC) are both natural polymeric materials that have the potential to replace traditional, nonrenewable polymers. In particular, the nanofibrillar form of bacterial cellulose makes it an effective reinforcement for PHB. Neat PHB, bacterial cellulose, and a composite of PHB/BC produced with 10 wt % cellulose were composted under accelerated aerobic test conditions, with biodegradability measured by the carbon dioxide evolution method, in conjunction with spectroscopic and diffraction methods to assess crystallinity changes during the biodegradation process. The PHB/BC composite biodegraded at a greater rate and extent than that of PHB alone, reaching 80% degradation after 30 days, whereas PHB did not reach this level of degradation until close to 50 days of composting. The relative crystallinity of PHB and PHB in the PHB/BC composite was found to increase in the initial weeks of degradation, with degradation occurring primarily in the amorphous region of the material and some recrystallization of the amorphous PHB. Small angle X-ray scattering indicates that the change in PHB crystallinity is accompanied by a change in morphology of semicrystalline lamellae. The increased rate of biodegradability suggests that these materials could be applicable to single-use applications and could rapidly biodegrade in compost on disposal.

  11. Investigation of a Novel NDE Method for Monitoring Thermomechanical Damage and Microstructure Evolution in Ferritic-Martensitic Steels for Generation IV Nuclear Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, Peter

    2013-09-30

    The main goal of the proposed project is the development of validated nondestructive evaluation (NDE) techniques for in situ monitoring of ferritic-martensitic steels like Grade 91 9Cr-1Mo, which are candidate materials for Generation IV nuclear energy structural components operating at temperatures up to ~650{degree}C and for steam-generator tubing for sodium-cooled fast reactors. Full assessment of thermomechanical damage requires a clear separation between thermally activated microstructural evolution and creep damage caused by simultaneous mechanical stress. Creep damage can be classified as "negligible" creep without significant plastic strain and "ordinary" creep of the primary, secondary, and tertiary kind that is accompanied by significant plastic deformation and/or cavity nucleation and growth. Under negligible creep conditions of interest in this project, minimal or no plastic strain occurs, and the accumulation of creep damage does not significantly reduce the fatigue life of a structural component so that low-temperature design rules, such as the ASME Section III, Subsection NB, can be applied with confidence. The proposed research project will utilize a multifaceted approach in which the feasibility of electrical conductivity and thermo-electric monitoring methods is researched and coupled with detailed post-thermal/creep exposure characterization of microstructural changes and damage processes using state-of-the-art electron microscopy techniques, with the aim of establishing the most effective nondestructive materials evaluation technique for particular degradation modes in high-temperature alloys that are candidates for use in the Next Generation Nuclear Plant (NGNP) as well as providing the necessary mechanism-based underpinnings for relating the two. Only techniques suitable for practical application in situ will be considered. As the project evolves and results accumulate, we will also study the use of this technique for monitoring other GEN IV

  12. Stellar evolution

    CERN Document Server

    Meadows, A J

    2013-01-01

    Stellar Evolution, Second Edition covers the significant advances in the understanding of birth, life, and death of stars.This book is divided into nine chapters and begins with a description of the characteristics of stars according to their brightness, distance, size, mass, age, and chemical composition. The next chapters deal with the families, structure, and birth of stars. These topics are followed by discussions of the chemical composition and the evolution of main-sequence stars. A chapter focuses on the unique features of the sun as a star, including its evolution, magnetic fields, act

  13. Nudging Evolution?

    Directory of Open Access Journals (Sweden)

    Katharine N. Farrell

    2013-12-01

    Full Text Available This Special Feature, "Nudging Evolution? Critical Exploration of the Potential and Limitations of the Concept of Institutional Fit for the Study and Adaptive Management of Social-Ecological Systems," aims to contribute toward the development of social theory and social research methods for the study of social-ecological system dynamics. Our objective is to help strengthen the academic discourse concerning if, and if so, how, to what extent, and in what concrete ways the concept of institutional "fit" might play a role in helping to develop better understanding of the social components of interlinkages between the socioeconomic-cultural and ecological dynamics of social-ecological systems. Two clearly discernible patterns provide a map of this Special Feature: (1 One pattern is the authors' positions regarding the place and role of normativity within their studies and assessment of institutional fit. Some place this at the center of their studies, exploring phenomena endogenous to the process of defining what constitutes institutional fit, whereas others take the formation of norms as a phenomenon exogenous to their study. (2 Another pattern is the type of studies presented: critiques and elaborations of the theory, methods for judging qualities of fit, and/or applied case studies using the concept. As a body of work, these contributions highlight that self-understanding of social-ecological place, whether explicit or implicit, constitutes an important part of the study object, i.e., the role of institutions in social-ecological systems, and that this is, at the same time, a crucial point of reference for the scholar wishing to evaluate what constitutes institutional fit and how it might be brought into being.

  14. Microstructure and texture evolution of ultra-thin grain-oriented silicon steel sheet fabricated using strip casting and three-stage cold rolling method

    Science.gov (United States)

    Song, Hong-Yu; Liu, Hai-Tao; Wang, Yin-Ping; Wang, Guo-Dong

    2017-03-01

    A 0.1 mm-thick grain-oriented silicon steel sheet was successfully produced using strip casting and three-stage cold rolling method. The microstructure, texture and inhibitor evolution during the processing was briefly analyzed. It was found that Goss texture was absent in the hot rolled sheet because of the lack of shear deformation. After normalizing, a large number of dispersed MnS precipitates with the size range of 15-90 nm were produced. During first cold rolling, dense shear bands were generated in the deformed ferrite grains, resulting in the intense Goss texture after first intermediate annealing. The microstructure was further refined and homogenized during the subsequent cold rolling and annealing processes. After primary recrystallization annealing, a homogeneous microstructure consisting of fine and equiaxed grains was produced while the associated texture was characterized by a strong γ-fiber texture. Finally, a complete secondary recrystallization microstructure consisting of entirely large Goss grains was produced. The magnetic induction B8 and iron loss P10/400 was 1.79 T and 6.9 W/kg, respectively.

  15. Development of a microprocessing-assisted cell-systematic evolution of ligands by exponential enrichment method for human umbilical vein endothelial cells

    Science.gov (United States)

    Terazono, Hideyuki; Kim, Hyonchol; Nomura, Fumimasa; Yasuda, Kenji

    2016-06-01

    We developed a microprocessing-assisted technique to select single-strand DNA aptamers that bind to unknown targets on the cell surface by modifying the conventional systematic evolution of ligands by exponential enrichment (cell-SELEX). Our technique involves 1) the specific selection of target-cell-surface-bound aptamers without leakage of intracellular components by trypsinization and 2) cloning of aptamers by microprocessing-assisted picking of single cells using magnetic beads. After cell-SELEX, the enriched aptamers were conjugated with magnetic beads. The aptamer-magnetic beads conjugates attached to target cells were collected individually by microassisted procedures using microneedles under a microscope. After that, the sequences of the collected magnetic-bead-bound aptamers were identified. As a result, a specific aptamer for the surface of target cells, e.g., human umbilical vein endothelial cells (HUVECs), was chosen and its specificity was examined using other cell types, e.g., HeLa cells. The results indicate that this microprocessing-assisted cell-SELEX method for identifying aptamers is applicable in biological research and clinical diagnostics.

  16. A new back-and-forth iterative method for time-reversed convection modeling: Implications for the Cenozoic evolution of 3-D structure and dynamics of the mantle

    Science.gov (United States)

    Glišović, Petar; Forte, Alessandro M.

    2016-06-01

    The 3-D distribution of buoyancy in the convecting mantle drives a suite of convection-related manifestations. Although seismic tomography is providing increasingly resolved images of the present-day mantle heterogeneity, the distribution of mantle density variations in the geological past is unknown, and, by implication, this is true for the convection-related observables. The one major exception is tectonic plate motions, since geologic data are available to estimate their history and they currently provide the only available constraints on the evolution of 3-D mantle buoyancy in the past. We developed a new back-and-forth iterative method for time-reversed convection modeling with a procedure for matching plate velocity data at different instants in the past. The crucial aspect of this reconstruction methodology is to ensure that at all times plates are driven by buoyancy forces in the mantle and not vice versa. Employing tomography-based retrodictions over the Cenozoic, we estimate the global amplitude of the following observables: dynamic surface topography, the core-mantle boundary ellipticity, the free-air gravity anomalies, and the global divergence rates of tectonic plates. One of the major benefits of the new data assimilation method is the stable recovery of much shorter wavelength changes in heterogeneity than was possible in our previous work. We now resolve what appears to be two-stage subduction of the Farallon plate under the western U.S. and a deeply rooted East African Plume that is active under the Ethiopian volcanic fields during the Early Eocene.

  17. Probability density evolution method of fatigue strength-life relationship%疲劳强度-寿命关系的概率密度演化方法

    Institute of Scientific and Technical Information of China (English)

    徐亚洲; 白国良

    2013-01-01

    Taking degradation of fatigue strength with increase in loading cycles into account, the joint probability density evolution equation of fatigue strength and random factors was derived using Euler description. A probability density S-N (p-S-N) surface was obtained with a numerical method, it was used to calculate the p-S-N curve with a given survivability. The analysis based on experimental fatigue data indicated that p-S-N curves with 95% survivability predicted by p-S-N, Monte Carlo simulation and S-N relation ship having parameters with a given fractile agree well; p-S-N provides a complete probability description of S-N relationship, independent of a probability distribution assumption.%基于疲劳强度随加载循环次数增加不断劣化的物理事实,采用Euler描述推导出疲劳强度与随机参数联合概率密度函数满足的演化方程.采用数值求解方法,给出疲劳强度-寿命概率密度曲面(probability density S-N),并可据此计算给定存活率的P-S-N曲线.基于疲劳试验结果的算例分析表明,疲劳强度-寿命概率密度曲面、MonteCarlo模拟及具有给定分位数参数的S-N关系三者计算的p-S-N曲线吻合良好.疲劳强度-寿命概率密度演化方法可不依赖分布假定给出S-N关系的完备概率描述.

  18. Galaxy Evolution

    Science.gov (United States)

    Matteucci, F.

    We review both the observational and theoretical constraints on the evolution of the abundances of heavy elements in gas and stars in galaxies of different morphological type. The main aim of this work is to document the progress made in our understanding of the physical processes regulating the chemical evolution of galaxies during the last sixteen years since the appearance, in this same journal (volume 5, page 287), of the well know review of Beatrice Tinsley, to whom I dedicate this paper. Finally, this article is addressed particularly to readers who do not actively work on galactic chemical evolution and who might use it as a cook book where the main ingredients are discussed and useful recipes can be found.

  19. 基于EMD的网络舆情演化分析与建模方法%Evolution Analysis and Modeling Method of Internet Public Opinions Based on EMD

    Institute of Scientific and Technical Information of China (English)

    周耀明; 王波; 张慧成

    2012-01-01

    The existing methods ignore multicomponent characteristics of evolution process of Internet public opinions, which leads to an unsatisfactory performance of analysis and modeling. To deal with the problem, this paper presents an evolution analysis and modeling method of Internet public opinions based on Empirical Mode Decomposition(EMD). It decomposes the evolution process of Internet public opinions by EMD, to form trend component, period component, mutation component and random component. Then it analyzes and models the evolution process of Internet public op.nions by analyzing and modeling the above-mentioned components. Experiments show that the components decomposed by EMD have clear physical meanings, which can help to analyze the evolution patterns of Internet public opinions; at the same time, the method has good forecasting performance, thus is more suitable.%现有研究忽略网络舆情演化过程的多成分特性,导致演化分析与建模效果较差.为此,提出一种基于经验模态分解(EMD)的网络舆情演化分析与建模方法.对演化过程进行EMD分解,形成演化过程的趋势成分、周期成分、突发成分和随机成分,通过对各成分进行分析与建模,实现网络舆情的演化分析与建模.实验结果表明,该方法通过EMD分解得到的各成分物理含义明显,有助于分析网络舆情的演化规律,同时具有较好的趋势预测效果,适合进行演化建模.

  20. Latitudinal variability of arsine, germane and phosphine in Jupiter's troposphere

    Science.gov (United States)

    Giles, Rohini Sara; Fletcher, Leigh N.; Irwin, Patrick Gerard Joseph

    2016-10-01

    High-resolution 5-μm observations of Jupiter from the CRIRES instrument at the Very Large Telescope are used to measure latitudinal variability in AsH3, GeH4 and PH3. The 5-micron region is a spectral window allowing us to probe down to Jupiter's middle troposphere (4-8 bar). CRIRES observations in 2012 and 2013 provide high-resolution (R=96,000) latitudinally-resolved spectra in the 4.7-5.2 μm region. In the middle troposphere, AsH3, GeH4and PH3 are disequilibrium species that are only present because of rapid upwelling from deeper regions of the planet. Their observed abundances depend on the chemical lifetimes, the strength of the vertical mixing and the rate of photolytic destruction, and are therefore likely to vary with latitude. We analyse the CRIRES observations using the NEMESIS radiative transfer code and retrieval algorithm in order to search for any latitudinal variability in the disequilibrium species. We find that there is a significant degeneracy between the retrieved gaseous abundances and the cloud structure - specifically, the scattering properties of the main tropospheric cloud deck, and the presence/absence of an additional deep cloud. Because of these degeneracies, there is no clear evidence for any variability in GeH4. However, for AsH3 and PH3, there are significant latitudinal differences in the observed lineshape that cannot be accounted for by clouds. We conclude that both of these gases show an enhancement at high latitudes. In the case of AsH3, the retrieved abundance varies from subsolar in the equatorial regions (as seen in previous studies) to supersolar in the polar regions. Our findings are in contrast with the theoretical simulations of Wang et al. (2016, doi:10.1016/j.icarus.2016.04.027), which predict that AsH3 and PH3 should not vary with latitude, and that GeH4 should decrease in abundance at high latitudes.

  1. Representing Evolution

    DEFF Research Database (Denmark)

    Hedin, Gry

    2012-01-01

    . This article discusses Willumsen's etching in the context of evolutionary theory, arguing that Willumsen is a rare example of an artist who not only let the theory of evolution fuel his artistic imagination, but also concerned himself with a core issue of the theory, namely to what extent it could be applied...

  2. An improved method for the determination of trace levels of arsenic and antimony in geological materials by automated hydride generation-atomic absorption spectroscopy

    Science.gov (United States)

    Crock, J.G.; Lichte, F.E.

    1982-01-01

    An improved, automated method for the determination of arsenic and antimony in geological materials is described. After digestion of the material in sulfuric, nitric, hydrofluoric and perchloric acids, a hydrochloric acid solution of the sample is automatically mixed with reducing agents, acidified with additional hydrochloric acid, and treated with a sodium tetrahydroborate solution to form arsine and stibine. The hydrides are decomposed in a heated quartz tube in the optical path of an atomic absorption spectrometer. The absorbance peak height for arsenic or antimony is measured. Interferences that exist are minimized to the point where most geological materials including coals, soils, coal ashes, rocks and sediments can be analyzed directly without use of standard additions. The relative standard deviation of the digestion and the instrumental procedure is less than 2% at the 50 ??g l-1 As or Sb level. The reagent-blank detection limit is 0.2 ??g l-1 As or Sb. ?? 1982.

  3. Origin and Evolution of Jute Analysed by SRAP and ISSR Methods%SRAP结合ISSR方法分析黄麻属的起源与演化

    Institute of Scientific and Technical Information of China (English)

    陶爱芬; 祁建民; 李木兰; 方平平; 林荔辉; 徐建堂

    2012-01-01

    [Objective] The objective of this study is to make clear the origin and evolution of Corchorus with two molecular methods (SRAP and ISSR). [Method] Ninety-six jute germplasms were analysed with sequence related amplified polymorphism (SRAP) combining with inter-simple sequence related (ISSR) method. The phylogenetic trees of Corchorus were constructed by MEGA and DPS software, and the divergence time of jute germplasm was calculated. [Result] The relative wild species located at the basic position of the dendrogram, and the divergence time of which was the longest, which indicated the relative wild species originated earliest and was the ancestors of cultivated jute. Africa was the center of origin of Corchorus, while China was the second original center of Corchorus. Among all the olitorius species, the divergence time of wild and cultivated species from Africa was the longest, so Africa was the center of origin for wild and cultivated olitorius species, while the areas which border on India, Burma and China was the second center of origin for cultivated olitorius species. South China, countries of South Asia and Southeast Asia which border on China were the origin center of wild capsularis species, and South region of China was the origin center of cultivated capsularis species. Taken together, the divergence time of the cultivated capsularis species was shorter than olitorius species, indicating this biotype originated later than olitorius species. [ Conclusion ] Africa has an important position in origin of Corchorus, which was the primary origin center of wild species, wild and cultivated olitorius species. South region of China was the origin center of cultivated capsularis species. The divergence time and phylogenetic trees of Corchorus were calculated more comprehensively by SRAP markers combining with ISSR molecular markers, and the scientific conclusion on origin and evolution of Corchorus was got with above methods.%[目的]以SRAP结合ISSR分子标记

  4. Ethics, evolution and culture.

    Science.gov (United States)

    Mesoudi, Alex; Danielson, Peter

    2008-08-01

    Recent work in the fields of evolutionary ethics and moral psychology appears to be converging on a single empirically- and evolutionary-based science of morality or ethics. To date, however, these fields have failed to provide an adequate conceptualisation of how culture affects the content and distribution of moral norms. This is particularly important for a large class of moral norms relating to rapidly changing technological or social environments, such as norms regarding the acceptability of genetically modified organisms. Here we suggest that a science of morality/ethics can benefit from adopting a cultural evolution or gene-culture coevolution approach, which treats culture as a second, separate evolutionary system that acts in parallel to biological/genetic evolution. This cultural evolution approach brings with it a set of established theoretical concepts (e.g. different cultural transmission mechanisms) and empirical methods (e.g. evolutionary game theory) that can significantly improve our understanding of human morality.

  5. Boussinesq evolution equations

    DEFF Research Database (Denmark)

    Bredmose, Henrik; Schaffer, H.; Madsen, Per A.

    2004-01-01

    This paper deals with the possibility of using methods and ideas from time domain Boussinesq formulations in the corresponding frequency domain formulations. We term such frequency domain models "evolution equations". First, we demonstrate that the numerical efficiency of the deterministic...... Boussinesq evolution equations of Madsen and Sorensen [Madsen, P.A., Sorensen, O.R., 1993. Bound waves and triad interactions in shallow water. Ocean Eng. 20 359-388] can be improved by using Fast Fourier Transforms to evaluate the nonlinear terms. For a practical example of irregular waves propagating over...... a submerged bar, it is demonstrated that evolution equations utilising FFT can be solved around 100 times faster than the corresponding time domain model. Use of FFT provides an efficient bridge between the frequency domain and the time domain. We utilise this by adapting the surface roller model for wave...

  6. 一种面向语义Web的组合服务演化方法研究%Research on the Semantic Web Oriented Method for the Evolution of Composite Service

    Institute of Scientific and Technical Information of China (English)

    王晓璇; 鲍爱华; 缪嘉嘉; 丁科; 王真

    2011-01-01

    To adapt composite services with changes in dynamic environment agility and effectively,a semantic Web oriented method for the evolution of compo-site service which named EM4CS was proposed systematically. Taking composite services described by OWL-S as research object, EM4CS divides the evolution process into 3 parts,and covers the evolution cycle in 6 stages, i. e. evolution requirements capturing, formal representation of evolution requirements,syntactic consistency maintenance, semantic consistency maintenance, confirmation of evolution results, publication and broadcasting of evolution results. The composite service evolution process was analyzed from the perspective of system engineering, and the evolution requirements were fulfilled in an iterative refined way, in which the syntactic and semantic consistency were also maintained. The composite service evolution support system, which follows EM4CS, named ESS4CS,was also introduced in this paper. E SS4CS can assist knowledge engineer in the whole process of composite service evolution,and the efficiency and precision of the evolution process are also improved.%为了敏捷、有效地调整动态环境下的组合服务,系统地提出一种面向语义Web的组合服务结构化演化方法EM4CS.EM4CS方法采用OWL-S语言描述的组合式语义Web服务为研究对象,将组合服务演化过程划分为3个部分、6个阶段,分别从演化需求获取、演化需求形式化表示、语法一致性维护、语义一致性维护、演化结果确认和演化结果发布与传播6个方面覆盖组合服务演化周期.EM4CS方法从系统工程的角度分析组合服务演化过程,以迭代求精的方式逐步实现演化需求,同时维持服务描述语法和语义的一致性.介绍了遵循EM4CS方法的组合服务演化支撑系统ESS4CS,该系统能够全程辅助知识工程师完成组合服务演化工作,能有效地提高组合服务演化的效率和精度.

  7. Micro-droplet based directed evolution outperforms conventional laboratory evolution

    DEFF Research Database (Denmark)

    Sjostrom, Staffan L.; Huang, Mingtao; Nielsen, Jens

    2014-01-01

    are confined in microfluidic droplets to prevent the phenotype, e.g. secreted enzymes, from leaking between cells. The method was benchmarked against and found to significantly outperform conventional adaptive laboratory evolution (ALE) in enriching enzyme producing cells. It was furthermore applied to enrich......We present droplet adaptive laboratory evolution (DrALE), a directed evolution method used to improve industrial enzyme producing microorganisms for e.g. feedstock digestion. DrALE is based linking a desired phenotype to growth rate allowing only desired cells to proliferate. Single cells...

  8. OLDA-based method for online topic evolution in network public opinion analysis%网络舆情中一种基于OLDA的在线话题演化方法

    Institute of Scientific and Technical Information of China (English)

    胡艳丽; 白亮; 张维明

    2012-01-01

    研究网络舆情分析中话题演化方法.首先分析网络舆情信息的特点;在此基础上,建立网络舆情信息模型,基于话题模型抽象描述文本内容的隐含语义,进而建立文本流在时间序列上的关联模型;进一步,提出基于OLDA的话题演化方法,针对舆情信息的特点,建立不同时间片话题间的关联.实验结果表明,该方法能够有效检测话题演化,为网络舆情分析提供了有效途径.%The topic evolution was investigated for network public opinion analysis. The properties of network public opinion information were analyzed firstly. Based on the properties, the latent semantics of textual data for network public opinion was described by using the topic model, and the text streams are modeled with a consideration of time for online analysis. Furthermore, a topic evolution method based on OLDA was proposed by incorporating the correlation of topics among time slices. The proposed method was experimentally verified to be efficient for detecting topic evolution of network public opinion.

  9. Group Evolution Discovery in Social Networks

    OpenAIRE

    Bródka, Piotr; Saganowski, Stanisław; Kazienko, Przemysław

    2013-01-01

    Group extraction and their evolution are among the topics which arouse the greatest interest in the domain of social network analysis. However, while the grouping methods in social networks are developed very dynamically, the methods of group evolution discovery and analysis are still uncharted territory on the social network analysis map. Therefore the new method for the group evolution discovery called GED is proposed in this paper. Additionally, the results of the first experiments on the ...

  10. CHEMICAL EVOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Calvin, Melvin

    1965-06-01

    How did life come to be on the surface of the earth? Darwin himself recognized that his basic idea of evolution by variation and natural selection must be a continuous process extending backward in time through that period in which the first living things arose and into the period of 'Chemical Evolution' which preceded it. We are approaching the examination of these events by two routes. One is to seek for evidence in the ancient rocks of the earth which were laid down prior to that time in which organisms capable of leaving their skeletons in the rocks to be fossilized were in existence. This period is sometime prior to approximately 600 million years ago. The earth is believed to have taken its present form approximately 4700 million years ago. We have found in rocks whose age is about 1000 million years certain organic molecules which are closely related to the green pigment of plants, chlorophyll. This seems to establish that green plants were already fluorishing prior to that time. We have now found in rocks of still greater age, namely, 2500 million years, the same kinds of molecules mentioned above which can be attributed to the presence of living organisms. If these molecules are as old as the rocks, we have thus shortened the time available for the generation of the complex biosynthetic sequences which give rise to these specific hydrocarbons (polyisoprenoids) to less than 2000 million years.

  11. method

    Directory of Open Access Journals (Sweden)

    L. M. Kimball

    2002-01-01

    Full Text Available This paper presents an interior point algorithm to solve the multiperiod hydrothermal economic dispatch (HTED. The multiperiod HTED is a large scale nonlinear programming problem. Various optimization methods have been applied to the multiperiod HTED, but most neglect important network characteristics or require decomposition into thermal and hydro subproblems. The algorithm described here exploits the special bordered block diagonal structure and sparsity of the Newton system for the first order necessary conditions to result in a fast efficient algorithm that can account for all network aspects. Applying this new algorithm challenges a conventional method for the use of available hydro resources known as the peak shaving heuristic.

  12. Review of Science Structure and Evolution of Bibliometric Methods%基于文献计量学的科学结构及其演化的研究方法述评

    Institute of Scientific and Technical Information of China (English)

    葛菲; 谭宗颖

    2012-01-01

      首先介绍几种主要的基于文献计量学的科学结构及演化研究方法,包括基于引文分析的方法、基于文本挖掘的内容词分析方法以及基于引文和内容词的混合分析方法,然后对这几种方法的优劣进行对比,最后建议将混合方法进一步应用于科学结构及演化研究及新兴趋势的探测,同时加强方法对比研究,以便针对不同的研究领域或者数据范围选择适当的方法,希望不同的混合方法能为情报学带来新的研究思路和方法,促进情报学的发展。%  Based on bibliometrics, several principal research methods of science structure and evolution, including the method of citation analysis, the method of content words analysis and the method of bibliometrics combining with content words analysis, are introduced at first, and then we compare the pros and cons of these methods. At last, we suggest that the hybrid method can be applied in researching science structure and evolution and detecting the emerging trends, and that we should enhance the contrast of these methods, in order to choose the appropriate method for different areas or data. We hope that different hybrid methods can enrich the methodology of information science and promote the development of information science.

  13. Evolution of Debris of a Tidally Disrupted Star by a Massive Black Hole Development of a Hybrid Scheme of the SPH and TVD Methods

    CERN Document Server

    Lee, H M; Lee, Hyung Mok; Kim, Sungsoo S.

    1996-01-01

    The evolution of the stellar debris after tidal disruption due to the super massive black hole's tidal force is difficult to solve numerically because of the large dynamical range of the problem. We developed an SPH (Smoothed Particle Hydrodynamics) - TVD (Total Variation Diminishing) hybrid code in which the SPH is used to cover a widely spread debris and the TVD is used to compute the stream collision more accurately. While the code in the present form is not sufficient to obtain desired resoultion, it could provide a useful tool in studying the aftermath of the stellar disruption by a massive black hole.

  14. New Computational Model Based on Finite Element Method to Quantify Damage Evolution Due to External Sulfate Attack on Self-Compacting Concretes

    KAUST Repository

    Khelifa, Mohammed Rissel

    2012-12-27

    Abstract: This work combines experimental and numerical investigations to study the mechanical degradation of self-compacting concrete under accelerated aging conditions. Four different experimental treatments are tested among them constant immersion and immersion-drying protocols allow an efficient external sulfate attack of the material. Significant damage is observed due to interfacial ettringite. A predictive analysis is then adopted to quantify the relationship between ettringite growth and mechanical damage evolution during aging. Typical 3D microstructures representing the cement paste-aggregate structures are generated using Monte Carlo scheme. These images are converted into a finite element model to predict the mechanical performance under different criteria of damage kinetics. The effect of ettringite is then associated to the development of an interphase of lower mechanical properties. Our results show that the observed time evolution of Young\\'s modulus is best described by a linear increase of the interphase content. Our model results indicate also that the interphase regions grow at maximum stress regions rather than exclusively at interfaces. Finally, constant immersion predicts a rate of damage growth five times lower than that of immersion-drying protocol. © 2012 Computer-Aided Civil and Infrastructure Engineering.

  15. Prediction of the Grain-Microstructure Evolution Within a Friction Stir Welding (FSW) Joint via the Use of the Monte Carlo Simulation Method

    Science.gov (United States)

    Grujicic, M.; Ramaswami, S.; Snipes, J. S.; Avuthu, V.; Galgalikar, R.; Zhang, Z.

    2015-09-01

    A thermo-mechanical finite element analysis of the friction stir welding (FSW) process is carried out and the evolution of the material state (e.g., temperature, the extent of plastic deformation, etc.) monitored. Subsequently, the finite-element results are used as input to a Monte-Carlo simulation algorithm in order to predict the evolution of the grain microstructure within different weld zones, during the FSW process and the subsequent cooling of the material within the weld to room temperature. To help delineate different weld zones, (a) temperature and deformation fields during the welding process, and during the subsequent cooling, are monitored; and (b) competition between the grain growth (driven by the reduction in the total grain-boundary surface area) and dynamic-recrystallization grain refinement (driven by the replacement of highly deformed material with an effectively "dislocation-free" material) is simulated. The results obtained clearly revealed that different weld zones form as a result of different outcomes of the competition between the grain growth and grain refinement processes.

  16. 基于类比分析的强势产品进化及其效应%The Evolution and Effects of Dominant Products Based on Analogy Method

    Institute of Scientific and Technical Information of China (English)

    罗军

    2011-01-01

    Based on analogy method between species evolution & products design, it analyzed the reasons why dominant products succeed. Combined with related consumption IT products, it illustrated the similarities on evolution of dominant species & dominant products, and summarized impacts on nature ecology, design progress and culture field. In conclusion, evolution of dominant products is harmful to environment and design' s diversity. It is meaningful to study on dominant products and make its definition as a whole, to protect eco-diversity, while avoid as far as possible its negative influence against culture.%从进化的角度类比了物种与产品,以消费类IT产品为例,分析了强势产品成功的原因,就强势产品对产品设计、自然环境和文化的影响进行了总结。认为:强势产品的进化加速了环境恶化与人的异化,阻碍了设计的多样化,研究IT产品中的强势产品对于从普遍意义上定义强势产品,维护产品的多样性,减少对文化的负面影响具有一定启示意义。

  17. Inlet Geomorphology Evolution Work Unit

    Science.gov (United States)

    2015-10-30

    the expected behavior and benefits of nearshore placement. Nearshore placement studies have been documented in two journal papers, one technical...Coastal Inlets Research Program Inlet Geomorphology Evolution Work Unit The Inlet Geomorphology Evolution work unit of the CIRP develops methods...sensing measurements, and USACE projects to create valuable guidance that address geomorphic questions. The present focus of the work unit is a common

  18. Method

    Directory of Open Access Journals (Sweden)

    Xixin Wang

    2012-01-01

    Full Text Available ZrO2 nanotube arrays were prepared by anodization method in aqueous electrolyte containing (NH42SO4 and NH4F. The morphology and structure of nanotube arrays were characterized through scanning electron microscope, X-ray diffraction, and infrared spectra analysis. The zirconia nanotube arrays were used as catalyst in esterification reaction. The effects of calcination temperature and electrolyte concentration on catalytic esterification activity have been investigated in detail. Experiments indicate that nanotube arrays have highest catalytic activity when the concentration of (NH42SO4 is 1 mol/L, the concentration of NH4F is 1 wt%, and the calcination temperature is 400°C. Esterification reaction yield of as much as 97% could be obtained under optimal conditions.

  19. 基于技术系统进化理论的换热器化学除垢方法的研究%Research on Chemical Anti- fouling Methods of Heat Exchanger Based on Technical System Evolution Theory

    Institute of Scientific and Technical Information of China (English)

    李耀中; 李英利; 胡建超

    2011-01-01

    基于技术系统进化理论预测换热器化学除垢方法的研究方向,寻找一种能够代替或改善现有的除垢方法,从而解决现有化学法存在的污染环境、损伤设备、成本较高等缺点。%Based on technical system evolution theory to predict future research direction for chemical anti - fouling methods of heat exchanger and finding a method to replace or improve the present anti - fouling one. Furthmore, could overcome the shortcoming of the present chemical method such as polluting the environment, damaging equipment,and higher cost etc.

  20. National radiotherapy Observatory. Inquiry report: situation at the end of 2010 and evolution since 2007. Context and method, results of data from 2010, conclusion; Observatoire national de la radiotherapie. Rapport d'enquete: situation fin 2010 et evolution depuis 2007. Contexte et methode, resultats des donnees 2010, conclusion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-01-15

    Illustrated by data tables and graphs, this document presents and discusses the results of an inquiry made on radiotherapy centres about their equipment (linear accelerators and additional equipment, number of days opened to patients, use, quality control and maintenance duration, treatment preparation, equipment dedicated to quality control), their activities (evolution of the number of treated patients, of treatments, and of treatment sessions between 2007 and 2010, number of sessions per apparatus, dosimetry, techniques), their personnel (evolution of the number of radiotherapists, radio-physicists, operators and dosimetrists, time dedicated to training), and their practices

  1. Groupware requirements evolution patterns

    NARCIS (Netherlands)

    Pumareja, Dulce Trinidad

    2013-01-01

    Requirements evolution is a generally known problem in software development. Requirements are known to change all throughout a system's lifecycle. Nevertheless, requirements evolution is a poorly understood phenomenon. Most studies on requirements evolution focus on changes to written specifications

  2. Method

    Directory of Open Access Journals (Sweden)

    Andrey Gnatov

    2015-01-01

    Full Text Available Recently repair and recovery vehicle body operations become more and more popular. A special place here is taken by equipment that provides performance of given repair operations. The most interesting things are methods for recovery of car body panels that allow the straightening without disassembling of car body panels and damaging of existing protective coating. Now, there are several technologies for repair and recovery of car body panels without their disassembly and dismantling. The most perspective is magnetic-pulse technology of external noncontact straightening. Basics of magnetic-pulse attraction, both ferromagnetic and nonferromagnetic thin-walled sheet metal, are explored. Inductor system calculation models of magnetic-pulse straightening tools are presented. Final analytical expressions for excited efforts calculation in the tools under consideration are introduced. According to the obtained analytical expressions, numerical evaluations of excited forces were executed. The volumetric epures of the attractive force radial distributions for different types of inductors were built. The practical testing of magnetic-pulse straightening with research tools is given. Using the results of the calculations we can create effective tools for an external magnetic-pulse straightening of car body panels.

  3. Has Human Evolution Stopped?

    OpenAIRE

    TEMPLETON, Alan R

    2010-01-01

    It has been argued that human evolution has stopped because humans now adapt to their environment via cultural evolution and not biological evolution. However, all organisms adapt to their environment, and humans are no exception. Culture defines much of the human environment, so cultural evolution has actually led to adaptive evolution in humans. Examples are given to illustrate the rapid pace of adaptive evolution in response to cultural innovations. These adaptive responses have important ...

  4. Topology evolution in polymer modification

    NARCIS (Netherlands)

    Kryven, I.; Iedema, P.D.

    2013-01-01

    A recent numerical method has opened new opportunities in multidimensional population balance modeling. Here, this method is applied to a full three-dimensional population balance model (PBM) describing branching topology evolution driven by chain end to backbone coupling. This process is typical fo

  5. Enhanced hydrogen evolution from water splitting using Fe-Ni codoped and Ag deposited anatase TiO{sub 2} synthesized by solvothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Tao [School of Chemical Engineering, Northwest University, No. 229 Taibai North Road, Xi’an, Shaanxi 710069 (China); School of Chemistry & Chemical Engineering, Nanjing University, No. 22 Hankou Road, Nanjing, Jiangsu 210093 (China); Liu, Enzhou; Liang, Xuhua [School of Chemical Engineering, Northwest University, No. 229 Taibai North Road, Xi’an, Shaanxi 710069 (China); Hu, Xiaoyun [Department of Physics, Northwest University, No. 229 Taibai North Road, Xi’an, Shaanxi 710069 (China); Fan, Jun, E-mail: fanjun@nwu.edu.cn [School of Chemical Engineering, Northwest University, No. 229 Taibai North Road, Xi’an, Shaanxi 710069 (China)

    2015-08-30

    Graphical abstract: - Highlights: • Fe-Ni/Ag/TiO{sub 2} nanocomposites displayed a higher hydrogen evolution rate. • TiO{sub 2} showed well optical property of light absorption by Fe, Ni and Ag modified. • More surface vacancies on TiO{sub 2} generated by the low cost metal introduced. • The separation rate of photoinduced electro-hole pairs was considerable improved. - Abstract: In this paper, the Fe-Ni co-doped and Ag deposited anatase TiO{sub 2} (Fe-Ni/Ag/TiO{sub 2}) nanocomposites were successfully prepared by a simple one-pot solvothermal approach. The investigations indicated that all as-prepared TiO{sub 2} samples were single anatase phase, and the impurity level was generated due to the Fe{sup 3+} or Ni{sup 2+} being located in the intrinsic band gap of TiO{sub 2}, while the Ag{sup +} ions could be transformed into metallic silver due to the reduction reaction and then loaded onto the surface of TiO{sub 2}. Compared with pure TiO{sub 2}, Fe-Ni/Ag/TiO{sub 2} composites with the sizes of Ag nanoparticles from 1.0 to 3.0 nm displayed the well optical property including higher visible light absorption activity and lower electron-hole pair recombination rate, and its absorption wavelength edge moved remarkably with a red shift to 700 nm. The photocatalytic water splitting was performed to produce H{sub 2} over the samples, and the experimental results indicate that Fe-Ni/Ag/TiO{sub 2} composites presented the highest H{sub 2} evolution rate, it can reach up to 793.86 μmol h{sup −1} g{sub cat}{sup −1} (λ > 400 nm for 6 h, energy efficiency is 0.25%), which was much higher than that of pure TiO{sub 2} for 9.57 μmol h{sup −1} g{sub cat}{sup −1}. In addition, a tentative photocatalytic mechanism is proposed to understand the enhancement mechanism over Fe-Ni codoped and Ag deposited anatase TiO{sub 2}.

  6. The regularity exploration for the evolution of ideological and political education method%思想政治教育方法演进发展的规律性探索

    Institute of Scientific and Technical Information of China (English)

    刘新庚; 朱新洲; 刘邦捷

    2014-01-01

    思想政治教育方法的演进发展必须遵循客观的发展规律。纵观其演进发展的历程,思想政治教育的方法总是按照特定社会的战略需要,秉承“宏观驾驭”和“战略导引”的基本理念,在引领社会意识形态的过程中不断变革,在化解社会矛盾中不断跨越,在导引人的思想发展中不断升华。其具体表现为:方法目标在引领思想政治的变革中更新,方法价值在引领伦理道德的发展中提升,方法内涵在引领文化思潮的演化中创新,方法取向在把握舆论导向中超越,方法内容在完善协调机制中深化,方法理念在人的思想觉悟进步中提升,方法机制在人的思想结构优化中完善,方法途径在人的思想功能拓展中多元。其演进发展的每一环节都体现着一定社会的客观要求,体现出“战略制导”的必然规律性。%The evolution and development of education method in ideology and politics should follow the law of the objective world. Throughout the history of evolution and development, education method in ideology and politics is always in consistence with the specific strategic needs of the society, adhering to the basic idea of“macro control”and“strategic guidance”, transforming continuously in leading the revolution of social ideology, distilling in resolving social contradictions, and rising in guiding people’s thoughts. It can be illustrated as follows:the target of method has been updated in the leading of the ideological and political change;the value of method has been promoted in leading the ethical development;the connotation of method has been innovated in leading the cultural ideological evolution;the orientation of method has surpassed in grasping the public opinion direction;the content of methods has been improved in perfecting coordination mechanism;the mechanism of method have been completed in the structure optimization of thought

  7. The generalizing Riccati equation mapping method in non-linear evolution equation: application to (2 + 1)-dimensional Boiti-Leon-Pempinelle equation

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Shundong [Department of Physics, Zhejiang Lishui University, Lishui 323000 (China)], E-mail: zhusd1965@sina.com

    2008-09-15

    The tanh method is used to find travelling wave solutions to various wave equations. In this paper, the extended tanh function method is further improved by the generalizing Riccati equation mapping method and picking up its new solutions. In order to test the validity of this approach, the (2 + 1)-dimensional Boiti-Leon-Pempinelle equation is considered. As a result, the abundant new non-travelling wave solutions are obtained.

  8. A method of opinion leaders discovering based on the topical evolution%一种基于话题演化的意见领袖发现方法

    Institute of Scientific and Technical Information of China (English)

    王臖; 张晖; 李波; 杨春明; 赵旭剑

    2016-01-01

    微博中的意见领袖不仅在社交网络的信息传播中发挥着举足轻重的作用,而且在网络舆情演化中也表现出显著的意见代表性。针对已有的意见领袖挖掘方法仅从复杂网络或者基本图模型来建模发现意见领袖,忽略了意见领袖在具体的话题演化中的意见代表性的问题,提出了基于话题演化的意见领袖发现的方法。该方法首先根据用户之间的交互构建图模型,然后利用寻找中心节点的图论算法挖掘潜在意见领袖,再利用话题演化模型判断潜在意见领袖的演化中心度,最后发现在整体舆情上的具有意见代表性的真实意见领袖。在新浪微博的话题数据集上的试验结果表明,该算法较仅考虑网络模型的意见领袖发现方法更优。%Existing studies about opinion leaders mining only adopted complex network methods or built graph model from networks,which ignored the specific role that opinion leaders play in the evolution of public opinion.To solve this problem,an opinion leaders discovering method based on the topic all evolution was presented.First,this method found latent opinion leaders by building a graph model based on the interaction between users and using the graph theory algo-rithm of looking for central node.Second,the evolution model of public opinion was used to judge the opinion repre-sentation of these opinion leaders.Finally,the true opinion leaders were found out,which had real lead resistance in the overall evaluation of public opinion.Experiment based on Sina MicroBlog datasets showed that this method performed better than those methods only consider the network model.

  9. Formation and evolution of MnNi clusters in neutron irradiated dilute Fe alloys modelled by a first principle-based AKMC method

    Energy Technology Data Exchange (ETDEWEB)

    Ngayam-Happy, R. [EDF-R and D, Departement Materiaux et Mecanique des Composants (MMC), Les Renardieres, F-77818 Moret sur Loing Cedex (France); Unite Materiaux et Transformations (UMET), UMR CNRS 8207, Universite de Lille 1, ENSCL, F-59655 Villeneuve d' Ascq Cedex (France); Laboratoire commun EDF-CNRS Etude et Modelisation des Microstructures pour le Vieillissement des Materiaux (EM2VM) (France); Becquart, C.S., E-mail: charlotte.becquart@univ-lille1.fr [Unite Materiaux et Transformations (UMET), UMR CNRS 8207, Universite de Lille 1, ENSCL, F-59655 Villeneuve d' Ascq Cedex (France); Laboratoire commun EDF-CNRS Etude et Modelisation des Microstructures pour le Vieillissement des Materiaux (EM2VM) (France); Domain, C. [EDF-R and D, Departement Materiaux et Mecanique des Composants (MMC), Les Renardieres, F-77818 Moret sur Loing Cedex (France); Unite Materiaux et Transformations (UMET), UMR CNRS 8207, Universite de Lille 1, ENSCL, F-59655 Villeneuve d' Ascq Cedex (France); Laboratoire commun EDF-CNRS Etude et Modelisation des Microstructures pour le Vieillissement des Materiaux (EM2VM) (France)

    2012-07-15

    An atomistic Monte Carlo model parameterised on electronic structure calculations data has been used to study the formation and evolution under irradiation of solute clusters in Fe-MnNi ternary and Fe-CuMnNi quaternary alloys. Two populations of solute rich clusters have been observed, which can be discriminated by whether or not the solute atoms are associated with self-interstitial clusters. Mn-Ni-rich clusters are observed at a very early stage of the irradiation in both modelled alloys, whereas the quaternary alloys contain also Cu-containing clusters. Mn-Ni-rich clusters nucleate very early via a self-interstitial-driven mechanism, earlier than Cu-rich clusters; the latter, however, which are likely to form via a vacancy-driven mechanism, grow in number much faster than the former, helped by the thermodynamic driving force to Cu precipitation in Fe, thereby becoming dominant in the low dose regime. The kinetics of the number density increase of the two populations is thus significantly different. Finally the main conclusion suggested by this work is that the so-called late blooming phases might as well be neither late, nor phases.

  10. Mechanism for the Evolution of Rural Consumption Methods of China and Their Action on Consumption Growth%农村消费方式变迁及其作用消费增长的机理

    Institute of Scientific and Technical Information of China (English)

    胡绍雨; 申曙光

    2014-01-01

    Since the reform and opening-up, China ’ s rural consumption methods gradually evolve from the traditional consumption methods such as decentralization, individualization, closure and low level which befit the traditional agriculture to modern consumption methods such as centralization, socialization and marketization which focus on the enjoyment and development, among which the consumption of rural durable products significantly shows the feature from“poverty to ample food and clothing”, then from“ample food and clothing to all-round well-being”, then from “all-round well-being to overall all-round well-being”, and the important factors affecting rural durable product consumption methods and their evolution direction are consumption habit, self-cognition of the consumers, social hierarchy attribution, regional location, consumption system, household life cycle and family income. Consumption method evolution can directly bring the increase of consumption quantity, however, the consumption method evolution comprehensively depends on the self-factor of the peasants, rural objective environment factors and the income of the peasants, and meanwhile, the promotion of the consumption method evolution and the peasant income increase can relatively use small social reform to realize the rapid increase of rural consumption. Thus, village reconstruction should pay the same attention to “improving rural environment”,“increasing the income of the peasants” and“raising the quality of the peasants” so that rural consumption can be effectively boosted.%改革开放以来,我国农村消费方式从与传统农业生产相适应的分散化、个体化、封闭性、低层次的传统消费方式,逐步向集中化、社会化、市场化、重视享受与发展的现代消费方式转变;其中,农村耐用消费品消费从“贫困-温饱”到“温饱-小康”再到“小康-全面小康”的三个阶段特征表现得尤为明显;消费

  11. Contribution to understanding historical evolution of rockfalls and landslides slopes using dendrochronological methods: example from the Kamienne Mts, Sudetes, SW Poland

    Science.gov (United States)

    Malik, Ireneusz; Owczarek, Piotr; Wistuba, Małgorzata; Migoń, Piotr; Kasprzak, Marek

    2013-04-01

    geomorphic process at this site is rock fall (avg. frequency: 1-2 events/10 years during the last 40 years). We have also confirmed present activity of creep on the scree slope (1-2/10 years on avg. during the last 40 years). The landslide slope at the Włostowa site shows a distinctly lower activity than the other two sites. Analysis of relief and dendrochronological studies indicate that these slopes represent different stages of landform evolution. The youngest stage is represented by the Turzyna site, intermediate stage by the Suchawa site, and the most advanced one by the Włostowa site. Results indicate that the evolution of landslide relief in the region begins from initial landforms with simple relief which later turn into landslides of complex structure and relief. In late stages the rock head scarp is actively remodelled by rock fall. Consequently, a scree slope develops and partly buries the proximal part of the landslide body.

  12. A full quantum analysis of the Stern–Gerlach experiment using the evolution operator method: analyzing current issues in teaching quantum mechanics

    Science.gov (United States)

    Benítez Rodríguez, E.; Arévalo Aguilar, L. M.; Piceno Martínez, E.

    2017-03-01

    To the quantum mechanics specialists community it is a well-known fact that the famous original Stern–Gerlach experiment (SGE) produces entanglement between the external degrees of freedom (position) and the internal degree of freedom (spin) of silver atoms. Despite this fact, almost all textbooks on quantum mechanics explain this experiment using a semiclassical approach, where the external degrees of freedom are considered classical variables, the internal degree is treated as a quantum variable, and Newton's second law is used to describe the dynamics. In the literature there are some works that analyze this experiment in its full quantum mechanical form. However, astonishingly, to the best of our knowledge the original experiment, where the initial states of the spin degree of freedom are randomly oriented coming from the oven, has not been analyzed yet in the available textbooks using the Schrödinger equation (to the best of our knowledge there is only one paper that treats this case: Hsu et al (2011 Phys. Rev. A 83 012109)). Therefore, in this contribution we use the time-evolution operator to give a full quantum mechanics analysis of the SGE when the initial state of the internal degree of freedom is completely random, i.e. when it is a statistical mixture. Additionally, as the SGE and the development of quantum mechanics are heavily intermingled, we analyze some features and drawbacks in the current teaching of quantum mechanics. We focus on textbooks that use the SGE as a starting point, based on the fact that most physicist do not use results from physics education research, and comment on traditional pedagogical attitudes in the physics community.

  13. Bibliometric evolution

    DEFF Research Database (Denmark)

    Nicolaisen, Jeppe; Frandsen, Tove Faber

    2015-01-01

    Applying a recently developed method for measuring the level of specialization over time for a selection of library and information science (LIS)-core journals seems to reveal that Journal of the Association for Information Science and Technology (JASIST) is slowly transforming into a specialty j...

  14. Evolution prediction from tomography

    Science.gov (United States)

    Dominy, Jason M.; Venuti, Lorenzo Campos; Shabani, Alireza; Lidar, Daniel A.

    2017-03-01

    Quantum process tomography provides a means of measuring the evolution operator for a system at a fixed measurement time t. The problem of using that tomographic snapshot to predict the evolution operator at other times is generally ill-posed since there are, in general, infinitely many distinct and compatible solutions. We describe the prediction, in some "maximal ignorance" sense, of the evolution of a quantum system based on knowledge only of the evolution operator for finitely many times 0evolution at times away from the measurement times. Even if the original evolution is unitary, the predicted evolution is described by a non-unitary, completely positive map.

  15. Evolution of Ore Deposits and Technology Transfer Project: Isotope and Chemical Methods in Support of the U.S. Geological Survey Science Strategy, 2003-2008

    Science.gov (United States)

    Rye, Robert O.; Johnson, Craig A.; Landis, Gary P.; Hofstra, Albert H.; Emsbo, Poul; Stricker, Craig A.; Hunt, Andrew G.; Rusk, Brian G.

    2010-01-01

    Principal functions of the U.S. Geological Survey (USGS) Mineral Resources Program are providing assessments of the location, quantity, and quality of undiscovered mineral deposits, and predicting the environmental impacts of exploration and mine development. The mineral and environmental assessments of domestic deposits are used by planners and decisionmakers to improve the stewardship of public lands and public resources. Assessments of undiscovered mineral deposits on a global scale reveal the potential availability of minerals to the United States and other countries that manufacture goods imported to the United States. These resources are of fundamental relevance to national and international economic and security policy in our globalized world economy. Performing mineral and environmental assessments requires that predictions be made of the likelihood of undiscovered deposits. The predictions are based on geologic and geoenvironmental models that are constructed for the diverse types of mineral deposits from detailed descriptions of actual deposits and detailed understanding of the processes that formed them. Over the past three decades the understanding of ore-forming processes has benefited greatly from the integration of laboratory-based geochemical tools with field observations and other data sources. Under the aegis of the Evolution of Ore Deposits and Technology Transfer Project (referred to hereinafter as the Project), a 5-year effort that terminated in 2008, the Mineral Resources Program provided state-of-the-art analytical capabilities to support applications of several related geochemical tools to ore-deposit-related studies. The analytical capabilities and scientific approaches developed within the Project have wide applicability within Earth-system science. For this reason the Project Laboratories represent a valuable catalyst for interdisciplinary collaborations of the type that should be formed in the coming years for the United States to meet

  16. Method of product generative design based on style evolution model%基于风格进化模型的产品生成设计方法

    Institute of Scientific and Technical Information of China (English)

    徐江; 王海贤; 孙守迁

    2012-01-01

    针对产品风格进化现象与创新设计问题,提出了产品风格历时性与共时性进化模型.在该模型基础上,结合生物遗传学理论定义产品风格基因.以典型汽车产品风格为例,在引入造型参数化表征前提下,运用主成分分析进行参数规约,并利用形状文法实现风格基因表达.然后,建立基于遗传算法的生成设计机制,该机制采用正交分析的策略来精简初始种群规模,通过适应度函数实现方案收敛.最后,开发出面向汽车产品的风格生成设计系统,并验证其有效性和实用性.风格进化规律、风格基因建模方法及创新设计技术对于动漫设计、平面设计、服装设计等领域研究也具有指导或借鉴作用.%Aiming at the style evolution phenomenon and the creative design problem, a product style diachronic and synchronic evolutionary mode is developed, and the product style gene is defined according to the theory of biological genetics. Specifically taking the typical automotive style as an example, the shape features are extracted and introduced as the form of parameter, which are dealt with the principal component analysis and the style genes are expressed with shape grammar. Further, the generative design mechanism based on genetic algorithm is constructed, which applies the orthogonal analysis to simplify the initial population size, and the convergence is achieved with the fitness function. Finally, the generative design system for automotive style is advanced and the effectiveness and practicality are verified. The research will have important and directive significance to enrich and expand the application in many fields such as architectural design, interaction design, fashion design, etc.

  17. 一种基于微分进化的采摘机器人运动反解方法%A Picking Robot Kinematic Inverse Solution Method Based on Differential Evolution

    Institute of Scientific and Technical Information of China (English)

    陈科尹; 邹湘军; 彭红星; 覃德泽

    2016-01-01

    According to the cumbersome and adaptive deficiencies of the picking robot kinematic inverse solution process , a picking robot kinematic inverse solution seeking method was presented based on the differential evolution algorithm . This method first utilizes picking robot motion positive equation to construct the objective function for solving picking robot motion inverse solution , and then uses the generalization and self-adaptive of the differential evolution algorithm to opti-mize the objective function , thus the picking robot kinematic inverse solution was solved .And in order to analyze the per-formance of this methodology , the traditional picking robot kinematic inverse solution and the picking robot kinematic in-verse solution based on the differential evolution algorithm were also respectively tested , which verified the effectiveness and robustness of the method in this paper .%针对传统的采摘机器人运动反解求法的求解过程过于繁琐及自适应性等不足,提出了一种基于微分进化的采摘机器人运动反解求取方法。该方法首先利用采摘机器人运动正解方程构造出求解采摘机器人运动反解的目标函数,然后运用微分进化算法的泛化性和自适应性对该目标函数进行优化处理,从而求解出采摘机器人运动反解。同时,为了分析该方法的性能,还分别对传统的采摘机器人运动反解和基于微分进化的采摘机器人运动反解进行了对比试验,从而验证了该方法的有效性和鲁棒性。

  18. The modified alternative (G'/G)-expansion method to nonlinear evolution equation: application to the (1+1)-dimensional Drinfel'd-Sokolov-Wilson equation.

    Science.gov (United States)

    Akbar, M Ali; Mohd Ali, Norhashidah Hj; Mohyud-Din, Syed Tauseef

    2013-01-01

    Over the years, (G'/G)-expansion method is employed to generate traveling wave solutions to various wave equations in mathematical physics. In the present paper, the alternative (G'/G)-expansion method has been further modified by introducing the generalized Riccati equation to construct new exact solutions. In order to illustrate the novelty and advantages of this approach, the (1+1)-dimensional Drinfel'd-Sokolov-Wilson (DSW) equation is considered and abundant new exact traveling wave solutions are obtained in a uniform way. These solutions may be imperative and significant for the explanation of some practical physical phenomena. It is shown that the modified alternative (G'/G)-expansion method an efficient and advance mathematical tool for solving nonlinear partial differential equations in mathematical physics.

  19. In-Situ Synchrotron X-ray Study of the Phase and Texture Evolution of Ceria and Superconductor Films Deposited by Chemical Solution Method

    DEFF Research Database (Denmark)

    Yue, Zhao; Grivel, Jean-Claude; He, Dong

    2012-01-01

    In situ synchrotron x-ray diffraction is used to study the phase and texture formation of ceria based films and superconductor films deposited by the chemical solution method on technical substrates. Combined analysis using in situ synchrotron x-ray diffraction, thermogravimetry/differential ther......In situ synchrotron x-ray diffraction is used to study the phase and texture formation of ceria based films and superconductor films deposited by the chemical solution method on technical substrates. Combined analysis using in situ synchrotron x-ray diffraction, thermogravimetry...

  20. CNEM: Cluster Based Network Evolution Model

    Directory of Open Access Journals (Sweden)

    Sarwat Nizamani

    2015-01-01

    Full Text Available This paper presents a network evolution model, which is based on the clustering approach. The proposed approach depicts the network evolution, which demonstrates the network formation from individual nodes to fully evolved network. An agglomerative hierarchical clustering method is applied for the evolution of network. In the paper, we present three case studies which show the evolution of the networks from the scratch. These case studies include: terrorist network of 9/11 incidents, terrorist network of WMD (Weapons Mass Destruction plot against France and a network of tweets discussing a topic. The network of 9/11 is also used for evaluation, using other social network analysis methods which show that the clusters created using the proposed model of network evolution are of good quality, thus the proposed method can be used by law enforcement agencies in order to further investigate the criminal networks

  1. Directed Evolution of Enzymes : Library Screening Strategies

    NARCIS (Netherlands)

    Leemhuis, Hans; Kelly, Ronan M.; Dijkhuizen, Lubbert

    2009-01-01

    Directed evolution has become the preferred engineering approach to generate tailor-made enzymes. The method follows the design guidelines of nature: Darwinian selection of genetic variants. This review discusses the different stages of directed evolution experiments with the focus on developments i

  2. Effect of hydrofluoric acid concentration on the evolution of photoluminescence characteristics in porous silicon nanowires prepared by Ag-assisted electroless etching method

    KAUST Repository

    Najar, Adel

    2012-01-01

    We report on the structural and optical properties of porous silicon nanowires (PSiNWs) fabricated using silver (Ag) ions assisted electroless etching method. Silicon nanocrystallites with sizes <5 nm embedded in amorphous silica have been observed from PSiNW samples etched using the optimum hydrofluoric acid (HF) concentration. The strongest photoluminescence (PL) signal has been measured from samples etched with 4.8 M of HF, beyond which a significant decreasing in PL emission intensity has been observed. A qualitative model is proposed for the formation of PSiNWs in the presence of Ag catalyst. This model affirms our observations in PL enhancement for samples etched using HF <4.8 M and the eventual PL reduction for samples etched beyond 4.8 M of HF concentration. The enhancement in PL signals has been associated to the formation of PSiNWs and the quantum confinement effect in the Si nanocrystallites. Compared to PSiNWs without Si-O x, the HF treated samples exhibited significant blue PL peak shift of 100 nm. This effect has been correlated to the formation of defect states in the surface oxide. PSiNWs fabricated using the electroless etching method can find useful applications in optical sensors and as anti-reflection layer in silicon-based solar cells. © 2012 American Institute of Physics.

  3. Simulation of phase diagram and transformation structure evolution by the use of Monte Carlo method; Monte Carlo ho wo katsuyoshita heiko jotaizu to hentai soshiki keisei no simulation

    Energy Technology Data Exchange (ETDEWEB)

    Matsumiya, T. [Nippon Steel Corporation, Tokyo (Japan)

    1996-08-20

    The Monte Carlo method was used to simulate an equilibrium diagram, and structural formation of transformation and recrystallization. In simulating the Cu-A equilibrium diagram, the calculation was performed by laying 24 face centered cubic lattices including four lattice points in all of the three directions, and using a simulation cell consisting of lattice points of a total of 24{sup 3}{times}4 points. Although this method has a possibility to discover existence of an unknown phase as a result of the calculation, problems were found left in handling of lattice mitigation, and in simulation of phase diagrams over phases with different crystal structures. In simulation of the transformation and recrystallization, discussions were given on correspondence of 1MCS to time when the lattice point size is increased, and on handling of nucleus formation. As a result, it was estimated that in three-dimensional grain growth, the average grain size is proportional to 1/3 power of the MCS number, and the real time against 1MCS is proportional to three power of the lattice point size. 11 refs., 8 figs., 2 tabs.

  4. Cooperative quantum differential evolution algorithm based method for optimizing neural networks%基于量子差分进化算法的神经网络优化方法

    Institute of Scientific and Technical Information of China (English)

    杜文莉; 周仁; 赵亮; 钱锋

    2012-01-01

    一般的神经网络的结构是固定的,在实际应用中容易造成冗余连接和高计算成本。该文采用了协同量子差分进化算法(cooperative quantum differential evolution algo-rithm,CQGADE)以同时优化神经网络的结构和参数,即采用量子遗传算法(quantum genetic algorithm,QGA)来优化神经网络的结构和隐层节点数,采用差分算法来优化神经网络的权值。训练后的神经网络的连接开关能有效删除冗余连接,算法的量子概率幅编码和协同机制可以提高神经网络的学习效率、逼近精度和泛化能力。仿真实验结果表明:用训练后的神经网络预测太阳黑子和蒸汽透平流量具有更好的预测精度和鲁棒性。%Neural network structures are fixed, which results in redundant connections and high computing costs. This paper presents a cooperative quantum differential evolution algorithm (CQGADE) that simultaneously optimizes the neural network structure and parameters. The quantum genetic algorithm is used to optimize the neural network structure and-the number of hidden nodes, while the differential evolution algorithm is used to optimize the neural network weights. This reduces redundant neural network structures, while the amplitude-based coding method and a cooperation mechanism improve the learning efficiency, approximation accuracy, and generalization. Simulations show that this algorithm has better prediction accuracy and robustness for predicting the number of sunspots and the flow of steam turbine.

  5. Topology evolutions of silhouettes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    We give the topology changing of the silhouette in 3D space while others study the projections in an image. Silhouettes play a crucial role in visualization, graphics and vision. This work focuses on the global behaviors of silhouettes, especially their topological evolutions, such as splitting, merging, appearing and disappearing. The dynamics of silhouettes are governed by the topology, the curvature of the surface, and the view point. In this paper, we work on a more theoretical level to give enumerative properties of the silhouette including: the integration of signed geodesic curvature along a silhouette is equal to the view cone angle; in elliptic regions, no silhouette can be contained in another one; in hyperbolic regions, ifa silhouette is homotopic to a point, then it has at least 4 cusps; finally, critical events can only happen when the view point is on the aspect surfaces (ruled surface of the asymptotic lines of parabolic points with surface itself). We also introduce a method to visualize the evolution of silhouettes, especially all the critical events where the topologies of the silhouettes change. The results have broad applications in computer vision for recognition, graphics for rendering and visualization.

  6. 内控目标演变及其对内控评价方法的影响%Internal Control Objectives Evolution and Its Influence on Internal Control Evaluation Method

    Institute of Scientific and Technical Information of China (English)

    马丽英

    2012-01-01

    The evolution of internal control objectives is divided into internal check,internal control system,internal control structure and integrated framework,the framework of risk management.Internal control evaluation method accordingly appears with simple evaluation which is subjective judgment dominated,detailed evaluation with the method of comprehensive scoring and risk-based evaluation oriented by risk control.From the comparison of evaluation method,risk-based assessment is the future development direction of internal control evaluation,but at present our country should adapt to the detailed evaluation with the method of comprehensive scoring.We must perfect the internal control evaluation standard system to ensure the smooth implementation of detailed evaluation method and realize the evaluation target.%内控目标的演变历程分为内部牵制、内部控制制度、内部控制结构和整合框架、风险管理框架阶段,内控评价方法相应出现了以主观判断为主的简易评价、以综合计分法为手段的详细评价和以风险控制为导向的风险基础评价。从评价方法的优劣比较来看,风险基础评价是未来内部控制评价的发展方向,但我国目前适宜采用以综合计分法为手段的详细评价,必须完善内部控制评价标准体系,才能保证详细评价法顺利实施,实现评价目标。

  7. Evolution of social versus individual learning in a subdivided population revisited: comparative analysis of three coexistence mechanisms using the inclusive-fitness method.

    Science.gov (United States)

    Kobayashi, Yutaka; Ohtsuki, Hisashi

    2014-03-01

    Learning abilities are categorized into social (learning from others) and individual learning (learning on one's own). Despite the typically higher cost of individual learning, there are mechanisms that allow stable coexistence of both learning modes in a single population. In this paper, we investigate by means of mathematical modeling how the effect of spatial structure on evolutionary outcomes of pure social and individual learning strategies depends on the mechanisms for coexistence. We model a spatially structured population based on the infinite-island framework and consider three scenarios that differ in coexistence mechanisms. Using the inclusive-fitness method, we derive the equilibrium frequency of social learners and the genetic load of social learning (defined as average fecundity reduction caused by the presence of social learning) in terms of some summary statistics, such as relatedness, for each of the three scenarios and compare the results. This comparative analysis not only reconciles previous models that made contradictory predictions as to the effect of spatial structure on the equilibrium frequency of social learners but also derives a simple mathematical rule that determines the sign of the genetic load (i.e. whether or not social learning contributes to the mean fecundity of the population).

  8. Styling Evolution for Tight-Fitting Garments.

    Science.gov (United States)

    Kwok, Tsz-Ho; Zhang, Yan-Qiu; Wang, Charlie C L; Liu, Yong-Jin; Tang, Kai

    2016-05-01

    We present an evolution method for designing the styling curves of garments. The procedure of evolution is driven by aesthetics-inspired scores to evaluate the quality of styling designs, where the aesthetic considerations are represented in the form of streamlines on human bodies. A dual representation is introduced in our platform to process the styling curves of designs, based on which robust methods for realizing the operations of evolution are developed. Starting from a given set of styling designs on human bodies, we demonstrate the effectiveness of set evolution inspired by aesthetic factors. The evolution is adaptive to the change of aesthetic inspirations. By this adaptation, our platform can automatically generate new designs fulfilling the demands of variations in different human bodies and poses.

  9. Feynman formulae for evolution semigroups

    Directory of Open Access Journals (Sweden)

    Ya. A. Butko

    2014-01-01

    Full Text Available The paper systematically describes an approach to solution of initial and initial-boundary value problems for evolution equations based on the representation of the corresponding evolution semigroups with the help of Feynman formulae. The article discusses some of the methods of constructing Feynman formulae for different evolution semigroups, presents specific examples of solutions of evolution equations. In particular, Feynman formula is obtained for evolution semigroups generated by multiplicative perturbations of generators of some initial semigroups. In this case semigroups on a Banach space of continuous functions defined on an arbitrary metric space are considered; Feynman formulae are constructed with the help of operator families, which are Chernoff equivalent to the initial unperturbed semigroups. The present result generalizes the author's paper \\Feynman formula for semigroups with multiplicative perturbed generators" and some of the results of the joint with O.G. Smolyanov and R.L. Schilling paper \\Lagrangian and Hamiltonian Feynman formulae for some Feller processes and their perturbations". The approach to the construction of Feynman formulae for semigroups with multiplicative and additive perturbed generators is illustrated with examples of the Cauchy problem for the Schrodinger equation, the approximation of transition probabilities of some Markov processes.Further, a wider class of additive and multiplicative perturbations of a particular generator | the Laplace operator | is considered in the paper. And Feynman formula for the solution of the Cauchy problem for a second order parabolic equation with unbounded variable coefficients is proved. In addition, the article describes a method for constructing Feynman formulae for solutions of the Cauchy | Dirichlet problem for parabolic differential equations. The method is also illustrated by a second order parabolic equation with variable coefficients. These results generalize some

  10. Policy Evolution of Economical and Intensive Use of Land in China based on Content Analysis Method%基于内容分析法的中国节约集约用地政策演进分析

    Institute of Scientific and Technical Information of China (English)

    吕晓; 牛善栋; 黄贤金; 赵雲泰; 赵小风; 钟太洋

    2015-01-01

    研究目的:概括总结中国节约集约用地政策的演进趋势.研究方法:内容分析法和概括总结方法.研究结果:(1)政策数量由1978—1998年间合计4项演变为1999—2014年间的年均4项,党中央、全国人大、国务院、相关部委颁布的政策分别占9.84%、3.28%、31.15%和55.73%;(2)政策形式多为通知、意见等,效力层级较低;(3)政策内容经历了由萌芽探索、基本确立到不断完善再到成熟发展的演进过程,涉及规模引导、布局优化、标准控制、市场配置、监督考评及法律责任等方面.研究结论:节约集约用地政策体系基本完备,但仍需加强批后监管,细化节约集约利用的过程与机制,探索节约集约利用新模式,实现城乡土地节约集约利用一体化,增强政策的可操作性.%The purpose of this study is to grasp the evolution trend of policies on economical and intensive use of land (EIUL)in China. The methods used in this study include the content analysis method, summarization and induction. The results show that: 1)a large number of relevant policies have been promulgated, by total 4 items from 1978 to 1998, and evolution of annual average 4 items from 1999 to 2014. The proportion of policy numbers at the Party Central Committee, the National People's Congress, the State Council and relevant ministries are 9.84%, 3.28%, 31.15%, and 55.73%, respectively. 2)The existing policies' forms are Notices, Opinions, and Management regulations and so on, therefore, the level of effectiveness of those policies is low, and the disciplining function is not strong. 3)Policy content experienced evolution process by embryonic and exploring stage, established basically, perfection constantly to mature, involving the guide scale, optimize structure, control standard, market allocation, supervision and examination, and legal responsibility. The study found that the existing policy system of EIUL has been basically perfected, is still needed

  11. The evolution of programs

    CERN Document Server

    Dershowitz, Nachum

    1983-01-01

    -Ecclesiastes 12:12 Programs are invariably subjected to many rorms or transrormation. After an initial version of a program has been designed and developed, it undergoes debugging and certification. In addition, most long-lived pro­ grams have a liCe-cycle that includes modifications to meet amended specifications and extensions for expanded capabilities. Such evolution­ ary aspects of programming are the topic of this monograph. We present rormal methods for manipulating programs and illustrate their applica­ tion with numerous examples. Such methods could be incorporated in semi-automated programming environments, where they would serve to ease the burden on the programmer. We begin by describing a method whereby a given program that achieves one goal can be modified to achieve a different goal or a pro­ gram that computes wrong results can be debugged to achieve the 2 Preface intended results. The abstraction of a set of cognate programs to obtain a program schema, and the instantiation of abstract sc...

  12. Has Human Evolution Stopped?

    Directory of Open Access Journals (Sweden)

    Alan R. Templeton

    2010-07-01

    Full Text Available It has been argued that human evolution has stopped because humans now adapt to their environment via cultural evolution and not biological evolution. However, all organisms adapt to their environment, and humans are no exception. Culture defines much of the human environment, so cultural evolution has actually led to adaptive evolution in humans. Examples are given to illustrate the rapid pace of adaptive evolution in response to cultural innovations. These adaptive responses have important implications for infectious diseases, Mendelian genetic diseases, and systemic diseases in current human populations. Moreover, evolution proceeds by mechanisms other than natural selection. The recent growth in human population size has greatly increased the reservoir of mutational variants in the human gene pool, thereby enhancing the potential for human evolution. The increase in human population size coupled with our increased capacity to move across the globe has induced a rapid and ongoing evolutionary shift in how genetic variation is distributed within and among local human populations. In particular, genetic differences between human populations are rapidly diminishing and individual heterozygosity is increasing, with beneficial health effects. Finally, even when cultural evolution eliminates selection on a trait, the trait can still evolve due to natural selection on other traits. Our traits are not isolated, independent units, but rather are integrated into a functional whole, so selection on one trait can cause evolution to occur on another trait, sometimes with mildly maladaptive consequences.

  13. Has human evolution stopped?

    Science.gov (United States)

    Templeton, Alan R

    2010-07-01

    It has been argued that human evolution has stopped because humans now adapt to their environment via cultural evolution and not biological evolution. However, all organisms adapt to their environment, and humans are no exception. Culture defines much of the human environment, so cultural evolution has actually led to adaptive evolution in humans. Examples are given to illustrate the rapid pace of adaptive evolution in response to cultural innovations. These adaptive responses have important implications for infectious diseases, Mendelian genetic diseases, and systemic diseases in current human populations. Moreover, evolution proceeds by mechanisms other than natural selection. The recent growth in human population size has greatly increased the reservoir of mutational variants in the human gene pool, thereby enhancing the potential for human evolution. The increase in human population size coupled with our increased capacity to move across the globe has induced a rapid and ongoing evolutionary shift in how genetic variation is distributed within and among local human populations. In particular, genetic differences between human populations are rapidly diminishing and individual heterozygosity is increasing, with beneficial health effects. Finally, even when cultural evolution eliminates selection on a trait, the trait can still evolve due to natural selection on other traits. Our traits are not isolated, independent units, but rather are integrated into a functional whole, so selection on one trait can cause evolution to occur on another trait, sometimes with mildly maladaptive consequences.

  14. Galaxy Formation and Evolution

    Science.gov (United States)

    Nagamine, Kentaro; Reddy, Naveen; Daddi, Emanuele; Sargent, Mark T.

    2016-07-01

    In this chapter, we discuss the current status of observational and computational studies on galaxy formation and evolution. In particular, a joint analysis of star-formation rates (SFRs), stellar masses, and metallicities of galaxies throughout cosmic time can shed light on the processes by which galaxies build up their stellar mass and enrich the environment with heavy elements. Comparison of such observations and the results of numerical simulations can give us insights on the physical importance of various feedback effects by supernovae and active galactic nuclei. In Sect. 1, we first discuss the primary methods used to deduce the SFRs, stellar masses, and (primarily) gas-phase metallicities in high-redshift galaxies. Then, we show how these quantities are related to each other and evolve with time. In Sect. 2, we further examine the distribution of SFRs in galaxies following the `Main Sequence' paradigm. We show how the so-called `starbursts' display higher specific SFRs and SF efficiencies by an order of magnitude. We use this to devise a simple description of the evolution of the star-forming galaxy population since z ˜3 that can successfully reproduce some of the observed statistics in the infrared (IR) wavelength. We also discuss the properties of molecular gas. In Sect. 3, we highlight some of the recent studies of high-redshift galaxy formation using cosmological hydrodynamic simulations. We discuss the physical properties of simulated galaxies such as luminosity function and escape fraction of ionizing photons, which are important statistics for reionization of the Universe. In particular the escape fraction of ionizing photons has large uncertainties, and studying gamma-ray bursts (which is the main topic of this conference) can also set observational constraints on this uncertain physical parameter as well as cosmic star formation rate density.

  15. Oxygen evolution reaction catalysis

    Science.gov (United States)

    Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

    2016-09-06

    An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

  16. Database Engines: Evolution of Greenness

    OpenAIRE

    Miranskyy, Andriy V.; Al-zanbouri, Zainab; Godwin, David; Bener, Ayse Basar

    2017-01-01

    Context: Information Technology consumes up to 10\\% of the world's electricity generation, contributing to CO2 emissions and high energy costs. Data centers, particularly databases, use up to 23% of this energy. Therefore, building an energy-efficient (green) database engine could reduce energy consumption and CO2 emissions. Goal: To understand the factors driving databases' energy consumption and execution time throughout their evolution. Method: We conducted an empirical case study of energ...

  17. Phylogeny and evolution of RNA structure.

    Science.gov (United States)

    Gesell, Tanja; Schuster, Peter

    2014-01-01

    Darwin's conviction that all living beings on Earth are related and the graph of relatedness is tree-shaped has been essentially confirmed by phylogenetic reconstruction first from morphology and later from data obtained by molecular sequencing. Limitations of the phylogenetic tree concept were recognized as more and more sequence information became available. The other path-breaking idea of Darwin, natural selection of fitter variants in populations, is cast into simple mathematical form and extended to mutation-selection dynamics. In this form the theory is directly applicable to RNA evolution in vitro and to virus evolution. Phylogeny and population dynamics of RNA provide complementary insights into evolution and the interplay between the two concepts will be pursued throughout this chapter. The two strategies for understanding evolution are ultimately related through the central paradigm of structural biology: sequence ⇒ structure ⇒ function. We elaborate on the state of the art in modeling both phylogeny and evolution of RNA driven by reproduction and mutation. Thereby the focus will be laid on models for phylogenetic sequence evolution as well as evolution and design of RNA structures with selected examples and notes on simulation methods. In the perspectives an attempt is made to combine molecular structure, population dynamics, and phylogeny in modeling evolution.

  18. Adaptive evolution of molecular phenotypes

    Science.gov (United States)

    Held, Torsten; Nourmohammad, Armita; Lässig, Michael

    2014-09-01

    Molecular phenotypes link genomic information with organismic functions, fitness, and evolution. Quantitative traits are complex phenotypes that depend on multiple genomic loci. In this paper, we study the adaptive evolution of a quantitative trait under time-dependent selection, which arises from environmental changes or through fitness interactions with other co-evolving phenotypes. We analyze a model of trait evolution under mutations and genetic drift in a single-peak fitness seascape. The fitness peak performs a constrained random walk in the trait amplitude, which determines the time-dependent trait optimum in a given population. We derive analytical expressions for the distribution of the time-dependent trait divergence between populations and of the trait diversity within populations. Based on this solution, we develop a method to infer adaptive evolution of quantitative traits. Specifically, we show that the ratio of the average trait divergence and the diversity is a universal function of evolutionary time, which predicts the stabilizing strength and the driving rate of the fitness seascape. From an information-theoretic point of view, this function measures the macro-evolutionary entropy in a population ensemble, which determines the predictability of the evolutionary process. Our solution also quantifies two key characteristics of adapting populations: the cumulative fitness flux, which measures the total amount of adaptation, and the adaptive load, which is the fitness cost due to a population's lag behind the fitness peak.

  19. 一种隐私暴露风险控制的服务演化方法%A Method of Service Evolution for Controlling Risk of Privacy Exposure

    Institute of Scientific and Technical Information of China (English)

    刘博; 黄志球; 王珊珊

    2014-01-01

    在Web服务组合中,用户隐私保护问题被广泛关注。当服务组合中有一个或多个成员服务对用户隐私数据的需求超出用户愿意给予的范围时,Web服务组合需要能够进行调整,以保证隐私数据的暴露符合用户需求。本文基于服务演化的理论,提出一种基于用户隐私需求的服务演化方法,其核心内容在于通过控制隐私数据的引用范围来达到降低隐私暴露风险的目的。最后通过一个旅游代理的实例分析,验证了本文提出的演化方法的可行性。%In the Web services composition, users'privacy protection has been received widespread attention.When the require-ment for users'privacy data by one or more member services in the service composition is beyond the range of users'willing to give, Web services composition need to be adjusted to ensure that the expose of privacy data is meeting the demand of the users. In this paper, we propose a new method of service evolution, which is based on the users'privacy requirements.The key to this method is by controlling the scope of privacy data's references to achieve the purpose of reducing the risk of privacy exposure.Fi-nally, through a travel agency case study, the feasibility of the proposed evolutionary approach is verified.

  20. An Evolution Model of Intelligence and Knowledge:The Influence of Learning Method on Species%具有智能生物种群的演化:学习方式对群体演化的影响

    Institute of Scientific and Technical Information of China (English)

    潘秋惠; 王震; 王恩鹏; 贺明峰

    2012-01-01

    We introduce intelligence gene into Penna model to describe an individual.Two kinds of leaning method based on intelligence,experience and environment are defined.We discuss the influence of learning method on the evolution of species.The results show that high utilization rate of external environment will increase the value of population size and knowledge.But the equilibrium value of intelligence decreases continuously with the increasing of environmental utilization rate.This will be a certain caution for human who contact more and more closely.%在Penna model基础上引入智能因素,建立了具有学习能力的生物演化模型,考虑智能、经验和环境因素定义了个体的学习方式,讨论了学习方式及学习的知识类型对种群演化的影响.从所得结果看出个体只有充分利用环境,才能使种群规模和群体平均知识有明显的增加.然而随着对外界环境利用程度的加强,种群的平均智能却是在下降,这一点对于联系越来越紧密的人类来说真是值得深思的一个问题.

  1. Museums teach evolution.

    Science.gov (United States)

    Diamond, Judy; Evans, E Margaret

    2007-06-01

    Natural history museums play a significant role in educating the general public about evolution. This article describes Explore Evolution, one of the largest evolution education projects funded by the National Science Foundation. A group of regional museums from the Midwestern United States worked with leading evolutionary scientists to create multiple permanent exhibit galleries and a curriculum book for youth. This program invites the public to experience current evolutionary research on organisms that range in size from HIV to whales. Learning research is being conducted on museum visitors to understand how they reason about evolution and to determine what influences the process of conceptual change.

  2. A mixture evolution scenario of AGN radio luminosity function

    CERN Document Server

    Yuan, Zunli; Zhou, Ming; Mao, Jirong

    2016-01-01

    We propose a mixture evolution scenario to model the evolution of the steep spectrum AGN (active galactic nuclear) radio luminosity function (RLF) based on a Bayesian method. In this scenario, the shape of RLF is determined together by the density and luminosity evolution. Our models indicate that the density evolution is positive until a redshift of $\\thicksim 0.9$ and then turns to be negative, while the luminosity evolution is positive to a higher redshift ($z \\thicksim 5$ for model B and $z \\thicksim 3.5$ for model C) and then turns to be negative. Our mixture evolution model works well, and the modeled RLFs are in good agreement with previous determinations. The mixture evolution scenario can naturally explain the luminosity dependent evolution of the RLFs.

  3. Predicting Community Evolution in Social Networks

    Directory of Open Access Journals (Sweden)

    Stanisław Saganowski

    2015-05-01

    Full Text Available Nowadays, sustained development of different social media can be observed worldwide. One of the relevant research domains intensively explored recently is analysis of social communities existing in social media as well as prediction of their future evolution taking into account collected historical evolution chains. These evolution chains proposed in the paper contain group states in the previous time frames and its historical transitions that were identified using one out of two methods: Stable Group Changes Identification (SGCI and Group Evolution Discovery (GED. Based on the observed evolution chains of various length, structural network features are extracted, validated and selected as well as used to learn classification models. The experimental studies were performed on three real datasets with different profile: DBLP, Facebook and Polish blogosphere. The process of group prediction was analysed with respect to different classifiers as well as various descriptive feature sets extracted from evolution chains of different length. The results revealed that, in general, the longer evolution chains the better predictive abilities of the classification models. However, chains of length 3 to 7 enabled the GED-based method to almost reach its maximum possible prediction quality. For SGCI, this value was at the level of 3–5 last periods.

  4. Iterated learning and the evolution of language.

    Science.gov (United States)

    Kirby, Simon; Griffiths, Tom; Smith, Kenny

    2014-10-01

    Iterated learning describes the process whereby an individual learns their behaviour by exposure to another individual's behaviour, who themselves learnt it in the same way. It can be seen as a key mechanism of cultural evolution. We review various methods for understanding how behaviour is shaped by the iterated learning process: computational agent-based simulations; mathematical modelling; and laboratory experiments in humans and non-human animals. We show how this framework has been used to explain the origins of structure in language, and argue that cultural evolution must be considered alongside biological evolution in explanations of language origins.

  5. Bringing molecules back into molecular evolution.

    Directory of Open Access Journals (Sweden)

    Claus O Wilke

    Full Text Available Much molecular-evolution research is concerned with sequence analysis. Yet these sequences represent real, three-dimensional molecules with complex structure and function. Here I highlight a growing trend in the field to incorporate molecular structure and function into computational molecular-evolution work. I consider three focus areas: reconstruction and analysis of past evolutionary events, such as phylogenetic inference or methods to infer selection pressures; development of toy models and simulations to identify fundamental principles of molecular evolution; and atom-level, highly realistic computational modeling of molecular structure and function aimed at making predictions about possible future evolutionary events.

  6. Chemical and mass evolution of galaxies

    CERN Document Server

    Ziegler, B L

    2004-01-01

    An introduction is given to projects investigating galaxy evolution quantitatively by spectroscopic observations of very distant galaxies that have weak apparent brightnesses and small sizes as it is feasible with 10m-class telescopes like SALT. Such methods encompass scaling relations like the Tully-Fisher and Fundamental Plane relations that can be utilized to determine the luminosity evolution and mass assembly of galaxies. The stellar populations can be analyzed with respect to age, metallicity, and chemical enrichment by measureing absorption line strengths. Possible effects on galaxy evolution of the environment in rich clusters of galaxies compared to the field are also addressed. For each method, recent applications are presented like the evolution of the TFR determined with 77 field spirals up to z=1, a study of the internal kinematics of distant cluster spirals and a comparison of the stellar populations of ellipticals in the field and in rich clusters at z=0.4.

  7. The diversity challenge in directed protein evolution.

    Science.gov (United States)

    Wong, Tuck Seng; Zhurina, Daria; Schwaneberg, Ulrich

    2006-05-01

    Over the past decade, we have witnessed a bloom in the field of evolutive protein engineering which is fueled by advances in molecular biology techniques and high-throughput screening technology. Directed protein evolution is a powerful algorithm using iterative cycles of random mutagenesis and screening for tailoring protein properties to our needs in industrial applications and for elucidating proteins' structure function relationships. This review summarizes, categorizes and discusses advantages and disadvantages of random mutagenesis methods used for generating genetic diversity. These random mutagenesis methods have been classified into four main categories depending on the method employed for nucleotide substitutions: enzyme based methods (Category I), synthetic chemistry based methods (Category II), whole cell methods (Category III) and combined methods (Category I-II, I-III and II-III). The basic principle of each method is discussed and varied mutagenic conditions are summarized in Tables and compared (benchmarked) to each other in terms of: mutational bias, controllable mutation frequency, ability to generate consecutive nucleotide substitutions and subset diversity, dependency on gene length, technical simplicity/robustness and cost-effectiveness. The latter comparison shows how highly-biased and limited current diversity creating methods are. Based on these limitations, strategies for generating diverse mutant libraries are proposed and discussed (RaMuS-Flowchart; KISS principle). We hope that this review provides, especially for researchers just entering the field of directed evolution, a guide for developing successful directed evolution strategies by selecting complementary methods for generating diverse mutant libraries.

  8. Framing Evolution Discussion Intellectually

    Science.gov (United States)

    Oliveira, Alandeom W.; Cook, Kristin; Buck, Gayle A.

    2011-01-01

    This study examines how a first-year biology teacher facilitates a series of whole-class discussions about evolution during the implementation of a problem-based unit. A communicative theoretical perspective is adopted wherein evolution discussions are viewed as social events that the teacher can frame intellectually (i.e., present or organize as…

  9. Evolution for Young Victorians

    Science.gov (United States)

    Lightman, Bernard

    2012-01-01

    Evolution was a difficult topic to tackle when writing books for the young in the wake of the controversies over Darwin's "Origin of Species." Authors who wrote about evolution for the young experimented with different ways of making the complex concepts of evolutionary theory accessible and less controversial. Many authors depicted presented…

  10. Software evolution with XVCL

    DEFF Research Database (Denmark)

    Zhang, Weishan; Jarzabek, Stan; Zhang, Hongyu

    2004-01-01

    This chapter introduces software evolution with XVCL (XML-based Variant Configuration Language), which is an XML-based metaprogramming technique. As the software evolves, a large number of variants may arise, especially whtn such kinds of evolutions are related to multiple platforms as shown in o...

  11. Kognition, evolution og Bibel

    DEFF Research Database (Denmark)

    Jensen, Hans Jørgen Lundager

    2012-01-01

    En opfordring til, at Bibelvidneskaberne oprienterer sig i retning af aktuelle teorier om bio-kulturel evolution (Merlin Donald, aksetids-teori hos fx Robert Bellah)......En opfordring til, at Bibelvidneskaberne oprienterer sig i retning af aktuelle teorier om bio-kulturel evolution (Merlin Donald, aksetids-teori hos fx Robert Bellah)...

  12. Self and Evolution.

    Science.gov (United States)

    Csikszentmihalyi, Mihaly

    1998-01-01

    Suggests the time has come for humans to direct their own individual evolution and the evolution of the entire species. Argues that ways must be found to encourage individuals, families, and cultures to discover and develop their differentiating characteristics and help these groups integrate with other cultures, customs, and belief systems.…

  13. Evolution of Constructivism

    Science.gov (United States)

    Liu, Chu Chih; Chen, I Ju

    2010-01-01

    The contrast between social constructivism and cognitive constructivism are depicted in different ways in many studies. The purpose of this paper is to summarize the evolution of constructivism and put a focus on social constructivism from the perception of Vygotsky. This study provides a general idea of the evolution of constructivism for people…

  14. Linear evolution of a shoreface nourishment

    OpenAIRE

    van Leeuwen, S; Dodd, Nicholas; Calvete Manrique, Daniel; Falqués Serra, Albert

    2007-01-01

    The morphological evolution of a shoreface nourishment is investigated by interpreting the nourishment as a linear perturbation of the natural system. The nourishment is projected onto the subset of linear eigenmodes with negative growth rates of the morphodynamical system. The evolution of these linear modes then determines the temporal behaviour of the shoreface nourishment. The method is presented, and results are shown for shoreface nourishments of different length scales on a straight co...

  15. 基于演化版本的 Deep Web 查询接口维护方法%Deep Web search interface maintenance method based on evolution version

    Institute of Scientific and Technical Information of China (English)

    束长波; 施化吉; 王基

    2015-01-01

    针对现有 Deep Web 信息集成系统没有考虑查询接口动态性的特点,造成本地接口与网络接口查询能力不对等的问题,提出一种基于演化版本的 Deep Web 查询接口维护方法。该方法通过构建本地接口的版本化模型来刻画接口的增量变化,识别变动比较活跃的属性集合;然后采取试探性查询来构建最优查询语句,获取网络接口数据源的变动信息,演化出本地接口的下一个版本,实现对本地查询接口数据源的信息维护的迭代过程。实验结果表明,该方法降低了深网环境变化对 Deep Web 信息集成带来的影响,确保了 Deep Web 查询接口的准确率和查全率的稳定性。%In order to solve the problems existed in the traditional Deep Web information integration system that without con-sidering the dynamic feature of search interface,causing local interface and network interface query ability is not equal.There-fore,this paper proposed a Deep Web search interface maintenance method based on evolution version.In this method,con-structing the version models of local search interface was to express the incremental change of it,and to extract the active attrib-ute set.Next,generating the best query string with the set and probing query was to extract the change content and get the next version of local interface.Finally,it could realize the iterative maintenance of local search interface data source.The experi-mental results show that this method is able to decrease the impact caused by deep Web network changing,and keep the recall and precision of Deep Web search interface in a stable state.

  16. Novel Rapid Molecular Modeling Method Based on Evolutional Tree for Human Adenovirus Hexon Proteins Family%进化树指导的腺病毒六邻体家族蛋白的快速建模

    Institute of Scientific and Technical Information of China (English)

    袁晓辉; 杨志伟; 高虹; 王迎晨; 曲章义; 任家毅; 王靖飞; 郭莹莹; 王雅贤; 华东; 吴晓敏

    2011-01-01

    Human adenoviruses (HAdVs) are responsible for many infectious diseases. 54 different serotypes of HAdVs have been identified so far, and the diversity of HAdVs has brought some difficulties to clinical diagnosis and therapy. In this study, a novel rapid modeling method for proteins family was developed on the basis of evolutionary tree, and by this method 7 hexon homologous proteins from D sub-specie Human adenovi-ruses( HAdVs) were modeled. An evolutionary tree of these 7 hexon protein amino acid sequences was constructed by neighbor-joining( NJ) algorithm; based on the information from the evolutional tree, an optimal modeling route was determined to accelerate the modeling of these hexons; And then, rapid modeling of he-xons was automatically completed using homology modeling method within MODELER and CHARMM program; and the sturcures were proved to be acceptable by two assessment methods. Compared with the traditional scheme, this novel method can significantly reduce the amount of calculation. Every hexon structure model produced by this novel rapid modelling method could be reliably superimposed to the corresponding model produced by the traditional method. The rapid modeling of HAdVs hexon protein is very important to the molecular designing of HAdVs vaccines and the development of rapid HAdVs diagnostic typing agents.%为实现对人腺病毒六邻体家族蛋白进行快速准确的结构建模,发展了一种新的基于进化树的预测蛋白质家族中一系列分子三维空间结构的快速建模方法,首先利用邻接法对7株D亚属人腺病毒的六邻体序列构建了基于距离的进化树,并根据进化树所提供的信息确定最佳六邻体家族蛋白渐进式建模路径,然后利用Modeler与Charmm程序实现六邻体家族蛋白的快速建模,新的建模方法与传统方法相比,需要的计算量大大减少,经过结构评估以及与传统方法建模所得到的结构进行比较,证实基于进化树的快速建模

  17. Experimental study on the evolution of heavy gas cylinder under reshock condition by PIV method%反射激波作用下重气柱界面演化的PIV研究

    Institute of Scientific and Technical Information of China (English)

    张赋; 翟志刚; 司廷; 罗喜胜

    2014-01-01

    Evolution of a membrane-less heavy (SF6 )gas cylinder under reshock condition is experimentally investigated in a horizontal shock tube with particle image velocimetry (PIV ) method.As a fundamental interface configuration,gas cylinder evolution impinged by a single shock wave is extensively investigated while the related research under reshock condition is sel-dom performed.Illuminated by a continuous laser sheet,the interface morphology after the inci-dent shock and reshock impact is characterized by glycol droplets and captured by a high-speed camera.The generation and development of counter-rotating vortex pair after incident shock im-pact is observed and secondary vortex rings,which have opposite rotating directions with the o-riginal vortex rings,are generated after the reshock passage because of the opposite pressure gra-dient induced by reshock compared with the incident shock.Because the velocity of the flow field after reshock is very small,the PIV measurement based on the Matpiv procedure is employed to capture the flow field after reshock.The continuous velocity and vorticity fields are obtained with the help of the continuous light source and high speed camera.Compared with the PIV algorithm based on the double-exposure technique,continuous velocity field can be obtained in a single test run based on the high-speed technique in this experiment.The circulation derived from PIV measurements is compared with the existed analytical model and a good agreement is achieved, which validates the feasibility of the experimental method.%在水平激波管中采用PIV方法研究了反射激波作用下SF6重气柱界面的发展演化。采用射流方法形成SF6无膜气柱界面,并以乙二醇作为示踪粒子。利用连续激光片光源结合高速摄影相机对流场进行显示,得到了反射激波作用下SF6气柱界面的发展过程。结果表明,入射激波的冲击会在界面上产生反向旋转的涡环结构,而反射激波的作

  18. The Evolution of GIM Programming

    Directory of Open Access Journals (Sweden)

    Anthony Meadows

    2010-11-01

    Full Text Available This article traces the origins and evolution of the music programs central to the Bonny Method (also called GIM or BMGIM. These programmed, sequenced western art music selections shape the core experience of GIM, eliciting intra-, inter-, and trans-personal phenomena through a range of visual, auditory, and kinesthetic feelings, images, memories, and metaphoric fantasies. Bonny’s original programs will be described and discussed in relation to GIM, and developments in programming will demonstrate how the Bonny Method programs have been expanded, including adaptations to music programming and selection.

  19. Machine learning for evolution strategies

    CERN Document Server

    Kramer, Oliver

    2016-01-01

    This book introduces numerous algorithmic hybridizations between both worlds that show how machine learning can improve and support evolution strategies. The set of methods comprises covariance matrix estimation, meta-modeling of fitness and constraint functions, dimensionality reduction for search and visualization of high-dimensional optimization processes, and clustering-based niching. After giving an introduction to evolution strategies and machine learning, the book builds the bridge between both worlds with an algorithmic and experimental perspective. Experiments mostly employ a (1+1)-ES and are implemented in Python using the machine learning library scikit-learn. The examples are conducted on typical benchmark problems illustrating algorithmic concepts and their experimental behavior. The book closes with a discussion of related lines of research.

  20. Freud and evolution.

    Science.gov (United States)

    Scharbert, Gerhard

    2009-01-01

    The essay analyzes the influence of evolutionary thought in the work of Sigmund Freud. Based on Freud's initial occupation as a neuro-anatomist and physiologist certain aspects stemming from the history of nature and developmental biological reasoning that played a role in his endeavours to find a new basis for medical psychology will be pointed out. These considerations are to be regarded as prolegomena of the task to reread Freud once again, and in doing so avoiding the verdict that holds his neuro-anatomic and comparative-morphological works as simply "pre-analytic." In fact, the time seems ripe to reconsider in a new context particularly those evolutionary, medical, and cultural-scientific elements in Freud's work that appear inconsistent at first sight. The substantial thesis is that Freud, given the fact that he was trained in comparative anatomy and physiology in the tradition of Johannes Müller, had the capability of synthesizing elements of this new point of view with the findings and interrogations concerning developmental history and the theory of evolution. More over, this was perceived not merely metaphoric, as he himself stressed it (Freud 1999, XIII, 99), but in the sense of Ubertragung, that inscribed terms and methods deriving from the given field into the realm of psychology. The moving force behind this particular Ubertragung came from a dynamically-neurological perception of the soul that emerged in France since 1800, which Freud came to know trough the late work of Charcot.

  1. Cultural Evolution and SETI

    Science.gov (United States)

    Dick, S. J.

    2009-12-01

    The Drake Equation for the number of radio communicative technological civilizations in the Galaxy encompasses three components of cosmic evolution: astronomical, biological and cultural. Of these three, cultural evolution totally dominates in terms of the rapidity of its effects. Yet, SETI scientists do not take cultural evolution into account, perhaps for understandable reasons, since cultural evolution is not well-understood even on Earth and is unpredictable in its outcome. But the one certainty for technical civilizations billions, millions, or even thousands of years older than ours is that they will have undergone cultural evolution. Cultural evolution potentially takes place in many directions, but this paper argues that its central driving force is the maintenance, improvement and perpetuation of knowledge and intelligence, and that to the extent intelligence can be improved, it will be improved. Applying this principle to life in the universe, extraterrestrials will have sought the best way to improve their intelligence. One possibility is that they may have long ago advanced beyond flesh-and-blood to artificial intelligence, constituting a postbiological universe. Although this subject has been broached, it has not been given the attention it is due from its foundation in cultural evolution. Nor has the idea of a postbiological universe been carried to its logical conclusion, including a careful analysis of the implications for SETI. SETI scientists, social scientists, and experts in AI should consider the strengths and weaknesses of this new paradigm.

  2. 基于概率密度演化的渡槽结构抗震分析%Seismic Analysis of Large-scale Aqueduct Structures Based on the Probability Density Evolution Method

    Institute of Scientific and Technical Information of China (English)

    曾波; 邢彦富; 刘章军

    2014-01-01

    Using the orthogonal expansion method of random processes,the non-stationary seismic acceleration process is represented as a linear combination of the standard orthogonal basis func-tions and the standard orthogonal random variables.Then,using the random function,these stand-ard orthogonal random variables in the orthogonal expansion are expressed as an orthogonal func-tion form of the basic random variable.Therefore,this method can use a basic random variable to express the original earthquake ground processes.The orthogonal expansion-random function ap-proach was used to generate 126 representative earthquake samples,and each representative sam-ple was assigned a given probability.The 126 representative earthquake samples were combined with the probability density evolution method of stochastic dynamical systems and random seis-mic responses of large-scale aqueduct structures was investigated.In this study,four cases were considered;aqueduct without water,aqueduct with water in the central trough,aqueduct with wa-ter in a two-side trough,and aqueduct with water in three troughs,and probability information of seismic responses for these cases were obtained.Moreover,using the proposed method,the seis-mic reliability of the aqueduct structures was efficiently calculated.This method provides a new and effective means for precise seismic analysis of large-scale aqueduct structures.%应用随机过程的正交展开方法,将地震动加速度过程展开为标准正交基函数与标准正交随机变量的线性组合形式。在此基础上采用随机函数的思想,将正交展开式中的标准正交随机变量表达为基本随机变量的函数形式,从而实现用一个基本随机变量来表达原地震动过程的目的。结合地震动过程的正交展开-随机函数模型与概率密度演化方法,对某大型渡槽结构进行随机地震反应分析与抗震可靠度计算;重点研究空槽和三槽有水等四种工况下渡槽结构

  3. Exact Travelling Wave Solutions to a Coupled Nonlinear Evolution Equation[

    Institute of Scientific and Technical Information of China (English)

    HUANGDing-Jiang; ZHANGHong-Qing

    2004-01-01

    By using an improved hyperbola function method, several types of exact travelling wave solutions to a coupled nonlinear evolution equation are obtained, which include kink-shaped soliton solutions, bell-shaped soliton solutions, envelop solitary wave solutions, and new solitary waves. The method can be applied to other nonlinear evolution equations in mathematical physics.

  4. Exact Travelling Wave Solutions to a Coupled Nonlinear Evolution Equation

    Institute of Scientific and Technical Information of China (English)

    HUANG Ding-Jiang; ZHANG Hong-Qing

    2004-01-01

    By using an improved hyperbola function method, several types of exact travelling wave solutions to a coupled nonlinear evolution equation are obtained, which include kink-shaped soliton solutions, bell-shaped soliton solutions, envelop solitary wave solutions, and new solitary waves. The method can be applied to other nonlinear evolution equations in mathematical physics.

  5. Galactic Chemical Evolution

    CERN Document Server

    Mollá, M; da Costa, R; Gibson, B K; Díaz, A I

    2016-01-01

    We analyze the evolution of oxygen abundance radial gradients resulting from our chemical evolution models calculated with different prescriptions for the star formation rate (SFR) and for the gas infall rate, in order to assess their respective roles in shaping gradients. We also compare with cosmological simulations and confront all with recent observational datasets, in particular with abundances inferred from planetary nebulae. We demonstrate the critical importance in isolating the specific radial range over which a gradient is measured, in order for their temporal evolution to be useful indicators of disk growth with redshift.

  6. Evolution of science I: Evolution of Mind

    CERN Document Server

    Vahia, M N

    2016-01-01

    The central nervous system and particularly the brain was designed to control the life cycle of a living being. With increasing size and sophistication, in mammals, the brain became capable of exercising significant control over life. In Homo Sapiens the brain became significantly powerful and capable of comprehension beyond survival needs with visualisation, formal thought and long term memory. Here we trace the rise of the powers of the brains of the Homo Sapiens and its capability of three comprehending the three spatial dimensions as well as time. By tracing the evolution of technology over the last millennium and particularly the late arrival of astronomy to discuss the evolution of the formal thinking process in humans. In a follow up paper we will trace the extensive use of this new faculty by humans to comprehend the working of the universe.

  7. Mode decomposition evolution equations.

    Science.gov (United States)

    Wang, Yang; Wei, Guo-Wei; Yang, Siyang

    2012-03-01

    Partial differential equation (PDE) based methods have become some of the most powerful tools for exploring the fundamental problems in signal processing, image processing, computer vision, machine vision and artificial intelligence in the past two decades. The advantages of PDE based approaches are that they can be made fully automatic, robust for the analysis of images, videos and high dimensional data. A fundamental question is whether one can use PDEs to perform all the basic tasks in the image processing. If one can devise PDEs to perform full-scale mode decomposition for signals and images, the modes thus generated would be very useful for secondary processing to meet the needs in various types of signal and image processing. Despite of great progress in PDE based image analysis in the past two decades, the basic roles of PDEs in image/signal analysis are only limited to PDE based low-pass filters, and their applications to noise removal, edge detection, segmentation, etc. At present, it is not clear how to construct PDE based methods for full-scale mode decomposition. The above-mentioned limitation of most current PDE based image/signal processing methods is addressed in the proposed work, in which we introduce a family of mode decomposition evolution equations (MoDEEs) for a vast variety of applications. The MoDEEs are constructed as an extension of a PDE based high-pass filter (Europhys. Lett., 59(6): 814, 2002) by using arbitrarily high order PDE based low-pass filters introduced by Wei (IEEE Signal Process. Lett., 6(7): 165, 1999). The use of arbitrarily high order PDEs is essential to the frequency localization in the mode decomposition. Similar to the wavelet transform, the present MoDEEs have a controllable time-frequency localization and allow a perfect reconstruction of the original function. Therefore, the MoDEE operation is also called a PDE transform. However, modes generated from the present approach are in the spatial or time domain and can be

  8. Chemical evolution and life

    Directory of Open Access Journals (Sweden)

    Malaterre Christophe

    2015-01-01

    Full Text Available In research on the origins of life, the concept of “chemical evolution” aims at explaining the transition from non-living matter to living matter. There is however strong disagreement when it comes to defining this concept more precisely, and in particular with reference to a chemical form of Darwinian evolution: for some, chemical evolution is nothing but Darwinian evolution applied to chemical systems before life appeared; yet, for others, it is the type of evolution that happened before natural selection took place, the latter being the birthmark of living systems. In this contribution, I review the arguments defended by each side and show how both views presuppose a dichotomous definition of “life”.

  9. Evolution, epigenetics and cooperation

    Indian Academy of Sciences (India)

    Patrick Bateson

    2014-04-01

    Explanations for biological evolution in terms of changes in gene frequencies refer to outcomes rather than process. Integrating epigenetic studies with older evolutionary theories has drawn attention to the ways in which evolution occurs. Adaptation at the level of the gene is givingway to adaptation at the level of the organism and higher-order assemblages of organisms. These ideas impact on the theories of how cooperation might have evolved. Two of the theories, i.e. that cooperating individuals are genetically related or that they cooperate for self-interested reasons, have been accepted for a long time. The idea that adaptation takes place at the level of groups is much more controversial. However, bringing together studies of development with those of evolution is taking away much of the heat in the debate about the evolution of group behaviour.

  10. Copper proteomes, phylogenetics and evolution.

    Science.gov (United States)

    Decaria, Leonardo; Bertini, Ivano; Williams, Robert J P

    2011-01-01

    This paper is a continuation of our study of the connection between the changing environment and the changing use of particular elements in organisms in the course of their combined evolution (Decaria, Bertini and Williams, Metallomics, 2010, 2, 706). Here we treat the changes in copper proteins in historically the same increasingly oxidising environmental conditions. The study is a bioinformatic analysis of the types and the numbers of copper domains of proteins from 435 DNA sequences of a wide range of organisms available in NCBI, using the method developed by Andreini, Bertini and Rosato in Accounts of Chemical Research 2009, 42, 1471. The copper domains of greatest interest are found predominantly in copper chaperones, homeostatic proteins and redox enzymes mainly used outside the cytoplasm which are in themselves somewhat diverse. The multiplicity of these proteins is strongly marked. The contrasting use of the iron and heme iron proteins in oxidations, mostly in the cytoplasm, is compared with them and with activity of zinc fingers during evolution. It is shown that evolution is a coordinated development of the chemistry of elements with use of novel and multiple copies of their proteins as their availability rises in the environment.

  11. Evolution, museums and society.

    Science.gov (United States)

    MacFadden, Bruce J

    2008-11-01

    Visitors to natural history museums have an incomplete understanding of evolution. Although they are relatively knowledgeable about fossils and geological time, they have a poor understanding of natural selection. Museums in the 21st century can effectively increase public understanding of evolution through interactive displays, novel content (e.g. genomics), engaging videos and cyberexhibits that communicate to a broad spectrum of society, both within the exhibit halls as well as outside the museum.

  12. Characteristic Evolution and Matching

    Directory of Open Access Journals (Sweden)

    Winicour Jeffrey

    2005-12-01

    Full Text Available I review the development of numerical evolution codes for general relativity based upon the characteristic initial value problem. Progress is traced from the early stage of 1D feasibility studies to 2D axisymmetric codes that accurately simulate the oscillations and gravitational collapse of relativistic stars and to current 3D codes that provide pieces of a binary black hole spacetime. A prime application of characteristic evolution is to compute waveforms via Cauchy-characteristic matching, which is also reviewed.

  13. Manipulation of quantum evolution

    Science.gov (United States)

    Cabera, David Jose Fernandez; Mielnik, Bogdan

    1994-01-01

    The free evolution of a non-relativistic charged particle is manipulated using time-dependent magnetic fields. It is shown that the application of a programmed sequence of magnetic pulses can invert the free evolution process, forcing an arbitrary wave packet to 'go back in time' to recover its past shape. The possibility of more general operations upon the Schrodinger wave packet is discussed.

  14. Controlled quantum evolutions and transitions

    CERN Document Server

    Petroni, N C; De Siena, S; Illuminati, F

    1999-01-01

    We study the nonstationary solutions of Fokker-Planck equations associated to either stationary or nonstationary quantum states. In particular we discuss the stationary states of quantum systems with singular velocity fields. We introduce a technique that allows to realize arbitrary evolutions ruled by these equations, to account for controlled quantum transitions. The method is illustrated by presenting the detailed treatment of the transition probabilities and of the controlling time-dependent potentials associated to the transitions between the stationary, the coherent, and the squeezed states of the harmonic oscillator. Possible extensions to anharmonic systems and mixed states are briefly discussed and assessed.

  15. Directed evolution strategies for improved enzymatic performance

    Directory of Open Access Journals (Sweden)

    Dalby Paul A

    2005-10-01

    Full Text Available Abstract The engineering of enzymes with altered activity, specificity and stability, using directed evolution techniques that mimic evolution on a laboratory timescale, is now well established. However, the general acceptance of these methods as a route to new biocatalysts for organic synthesis requires further improvement of the methods for both ease-of-use and also for obtaining more significant changes in enzyme properties than is currently possible. Recent advances in library design, and methods of random mutagenesis, combined with new screening and selection tools, continue to push forward the potential of directed evolution. For example, protein engineers are now beginning to apply the vast body of knowledge and understanding of protein structure and function, to the design of focussed directed evolution libraries, with striking results compared to the previously favoured random mutagenesis and recombination of entire genes. Significant progress in computational design techniques which mimic the experimental process of library screening is also now enabling searches of much greater regions of sequence-space for those catalytic reactions that are broadly understood and, therefore, possible to model. Biocatalysis for organic synthesis frequently makes use of whole-cells, in addition to isolated enzymes, either for a single reaction or for transformations via entire metabolic pathways. As many new whole-cell biocatalysts are being developed by metabolic engineering, the potential of directed evolution to improve these initial designs is also beginning to be realised.

  16. Creationism, Evolution, and Science Education

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Eugenie C. (National Center for Science Education)

    2005-06-22

    Many topics in the curriculum of American schools are controversial, but perhaps the one with the longest tenure is evolution. Three arguments are made against evolution: that it is allegedly weak science ('evolution is a theory in crisis'); that it is incompatible with religion; and that it is only 'fair' to 'balance' evolution with creationism. Regardless of the appropriateness of their application to science education, all three of the arguments are made to try to restrict the teaching of evolution. Variants of the fairness argument such as balancing evolution with 'scientific alternatives to evolution' or balancing evolution with 'arguments against evolution' have in fact become the current predominant antievolutionist strategy. Current events in the creationism/evolution controversy will be reviewed, and suggestions made for how to promote sound science education in the schools.

  17. Some new solutions of nonlinear evolution equations with variable coefficients

    Science.gov (United States)

    Virdi, Jasvinder Singh

    2016-05-01

    We construct the traveling wave solutions of nonlinear evolution equations (NLEEs) with variable coefficients arising in physics. Some interesting nonlinear evolution equations are investigated by traveling wave solutions which are expressed by the hyperbolic functions, the trigonometric functions and rational functions. The applied method will be used in further works to establish more entirely new solutions for other kinds of such nonlinear evolution equations with variable coefficients arising in physics.

  18. THE NUMERICAL METHODS OF THE RESEARCH IN THE ORBITAL EVOLUTION OF THE ASTEROIDS%小行星轨道演化研究中的数值方法

    Institute of Scientific and Technical Information of China (English)

    刘林; 季江徽; 廖新浩

    2001-01-01

    小行星是太阳系最重要的一类小天体,主要分布在两个区域;火星和木星轨道之间的一条主带和近地空间.近地小行星轨道的最大特点是其轨道半长径与地球轨道半长径相近,或近日距离接近甚至小于日地平均距离,其运动可深入到地球轨道的内部,这将导致该类小行星与地球(还有金星、火星等)十分靠近甚至发生碰撞.这一特征给其轨道演化数值研究带来一些困难,包括天体力学方法中一般消除碰撞奇点的正规化处理以及对定性研究十分成功的辛算法都将在不同程度上失效.通过对几种常用数值方法(包括辛算法)计算效果的比较,根据小天体运动自身的特性,给出了相应处理措施,从而可提高计算结果的可靠性.%The asteroids are the most important small bodies in the solarsystem,and they mainly lies in the two locations-a main belt between the Mars's orbit and the Jupiter's and the near-Earth space.The most feature of the orbits of Near-Earth Asteroids(NEAs) is that the semi-major axes of the orbits are nearly equal to that of the Earth or the perihelia distances are approximate to or even less than the mean distance between the Sun and the Earth,thus they could move into inside of the Earth's orbit,so that they might close approach or even colliside with the Earth (or other planets,such as the Venus,the Mars,etc.).The characteristic brings about some difficulties in the numerical research during their orbital evolution,which leads to the failure of the normalization technique in the general removal impact singularities of celestial mechanics methods and the Symplectic Algorithm which is successfully applied to the investigation in quality.By comparing the computation effects of several common numerical methods(including Symplectic Algorithm),and considering the nature of the movement of the small bodies,the corresponding treatments are provided here to improve the

  19. Web服务组合中业务流程演化影响范围判定方法%Decision method for affected scope of business process evolution in Web service composition

    Institute of Scientific and Technical Information of China (English)

    尤殿龙; 申利民; 刘芳

    2013-01-01

    Aiming at the unknowable characteristic for each other's internal business processes of the services involved in the evolution,the types of evolution were decided based on the service changes in the internal business processes before and after the evolution according to open-bisimulation theory.By judging the attachment services at the precursor states sets or the subsequent states sets of the affected state nodes in the internal business process,the involved services was decided.By calculating the boundary of business process evolution's effect in internal services,the evolved scope of each service was decided,and the affected scope of business process evolution in service composition was further obtained.For the above questions,the decision rules and algorithms were given to ensure that the evolution was taken place only in the affected area and all the state nodes affected were evolved.%针对组合业务流程中各参与演化的服务对彼此内部业务流程不可知的特点,依据互模拟理论,以服务在演化前后内部业务流程的变化特点判定演化类型;通过判定内部业务流程中受影响状态节点的前驱状态集或后继状态集的归属服务来确定受波及的服务;通过计算服务内部业务流程演化影响范围的边界得出单个服务的受影响范围,进而得出服务组合中业务流程演化的影响范围.针对以上问题,给出了其判定规则和算法,使得演化仅在受波及区域内发生,并且所有受影响的状态节点都可能参与演化.

  20. The Evolution of Language

    Science.gov (United States)

    Nowak, Martin A.; Krakauer, David C.

    1999-07-01

    The emergence of language was a defining moment in the evolution of modern humans. It was an innovation that changed radically the character of human society. Here, we provide an approach to language evolution based on evolutionary game theory. We explore the ways in which protolanguages can evolve in a nonlinguistic society and how specific signals can become associated with specific objects. We assume that early in the evolution of language, errors in signaling and perception would be common. We model the probability of misunderstanding a signal and show that this limits the number of objects that can be described by a protolanguage. This "error limit" is not overcome by employing more sounds but by combining a small set of more easily distinguishable sounds into words. The process of "word formation" enables a language to encode an essentially unlimited number of objects. Next, we analyze how words can be combined into sentences and specify the conditions for the evolution of very simple grammatical rules. We argue that grammar originated as a simplified rule system that evolved by natural selection to reduce mistakes in communication. Our theory provides a systematic approach for thinking about the origin and evolution of human language.

  1. Characteristic Evolution and Matching

    Directory of Open Access Journals (Sweden)

    Jeffrey Winicour

    2012-01-01

    Full Text Available I review the development of numerical evolution codes for general relativity based upon the characteristic initial-value problem. Progress in characteristic evolution is traced from the early stage of 1D feasibility studies to 2D-axisymmetric codes that accurately simulate the oscillations and gravitational collapse of relativistic stars and to current 3D codes that provide pieces of a binary black-hole spacetime. Cauchy codes have now been successful at simulating all aspects of the binary black-hole problem inside an artificially constructed outer boundary. A prime application of characteristic evolution is to extend such simulations to null infinity where the waveform from the binary inspiral and merger can be unambiguously computed. This has now been accomplished by Cauchy-characteristic extraction, where data for the characteristic evolution is supplied by Cauchy data on an extraction worldtube inside the artificial outer boundary. The ultimate application of characteristic evolution is to eliminate the role of this outer boundary by constructing a global solution via Cauchy-characteristic matching. Progress in this direction is discussed.

  2. Evolution of Things

    CERN Document Server

    Eiben, A E; Schut, M; Kernbach, S

    2011-01-01

    Evolution is one of the major omnipresent powers in the universe that has been studied for about two centuries. Recent scientific and technical developments make it possible to make the transition from passively understanding to actively mastering evolution. As of today, the only area where human experimenters can design and manipulate evolutionary processes in full is that of Evolutionary Computing, where evolutionary processes are carried out in a digital space, inside computers, in simulation. We argue that in the near future it will be possible to move evolutionary computing outside such imaginary spaces and make it physically embodied. In other words, we envision the "Evolution of Things", rather than just the evolution of code, leading to a new field of Embodied Artificial Evolution (EAE). The main objective of the present paper is to offer an umbrella term and vision in order to aid the development of this high potential research area. To this end, we introduce the notion of EAE, discuss a few examples...

  3. Development of an analytic method for arsenic's determination in lime and tortilla; Desarrollo de un metodo analitico para determinacion de arsenico en cal y tortilla

    Energy Technology Data Exchange (ETDEWEB)

    Huato Soberanis, Julio; Ogura, Tetsuya [Universidad Autonoma de Guadalajara, Guadalajara, Jalisco (Mexico)

    1995-02-01

    A spectrophotometric method to determine As in tortilla and lime has been optimized, modifying the AsH{sub 3} generator. The reaction between arsin (AsH{sub 3}){sub 4} and diethyldithiocarbamate of Ag (AgDDC); was followed spectrophotometrically. The conditions under which the As remains in the ash during the calcination of the tortillas were studied. It was found that when they were heated in a quartz tube with a careful control of the air flow and oxygen, as well as the heating temperature, the arsenic loss in minimized. [Spanish] Se ha optimizado el metodo para determinar As en la tortilla y cal mediante espectrometria en el visible del color producido en la reaccion entre Arsina (AsH{sub 3}){sub 4} y dietilditiocarbamato de plata (AgDDC); modificando el generador de AsH{sub 3}. Se han buscado las condiciones en las que el arsenico permanece en las cenizas de la calcinacion de las tortillas; encontrandose que las tortillas deben calentarse en un tubo de cuarzo con control del flujo de aire y oxigeno asi como de la temperatura de calentamiento.

  4. AGN evolution from a galaxy evolution viewpoint

    CERN Document Server

    Caplar, Neven; Trakhtenbrot, Benny

    2014-01-01

    We explore the connections between the evolving galaxy and AGN populations. We present a simple phenomenological model that links the evolving galaxy mass function and the evolving quasar luminosity function, motivated by similarities between the two, which makes specific and testable predictions for the distribution of host galaxy masses for AGN of different luminosities. We show that the phi$^{*}$ normalisations of the galaxy mass function and the AGN luminosity function closely track each other over a wide range of redshifts, implying a constant "duty cycle" of AGN activity. The strong redshift evolution in the AGN break luminosity $L^*$ is produced by either an evolution in the distribution of Eddington rations, or in the $m_{bh}/m_{*}$ mass ratio, or both. An evolving $m_{bh}/m_{*}$ ratio, such that it is ten times higher at $z \\sim 2$ (i.e. roughly following $(1+z)^{2}$), reproduces the observed distribution of SDSS quasars in the ($m_{bh},L$) plane and accounts for the apparent "sub-Eddington boundary"...

  5. Evolution Properties of Modules in Complex Networks

    Institute of Scientific and Technical Information of China (English)

    LI Ke-Ping; GAO Zi-You

    2008-01-01

    In complex networks, network modules play a center role, which carry out a key function. In this paper, we introduce the spatial correlation function to describe the relationships among the network modules. Our focus is to investigate how the network modules evolve, and what the evolution properties of the modules are. In order to test the proposed method, as the examples, we use our method to analyze and discuss the ER random network and scale-free network. Rigorous analysis of the existing data shows that the introduced correlation function is suitable for describing the evolution properties of network modules. Remarkably, the numerical simulations indicate that the ER random network and scale-free network have different evolution properties.

  6. NLO JIMWLK evolution unabridged

    CERN Document Server

    Kovner, Alex; Mulian, Yair

    2014-01-01

    In Ref. [1] we presented the JIMWLK Hamiltonian for high energy evolution of QCD amplitudes at the next-to-leading order accuracy in $\\alpha_s$. In the present paper we provide details of our original derivation, which was not reported in [1], and provide the Hamiltonian in the form appropriate for action on color singlet as well as color nonsinglet states. The rapidity evolution of the quark dipole generated by this Hamiltonian is computed and compared with the corresponding result of Balitsky and Chirilli [2]. We then establish the equivalence between the NLO JIMWLK Hamiltonian and the NLO version of the Balitsky's hierarchy [3], which includes action on nonsinglet combinations of Wilson lines. Finally, we present complete evolution equation for three-quark Wilson loop operator, thus extending the results of Grabovsky [4].

  7. Software architecture evolution

    DEFF Research Database (Denmark)

    Barais, Olivier; Le Meur, Anne-Francoise; Duchien, Laurence

    2008-01-01

    Software architectures must frequently evolve to cope with changing requirements, and this evolution often implies integrating new concerns. Unfortunately, when the new concerns are crosscutting, existing architecture description languages provide little or no support for this kind of evolution....... The software architect must modify multiple elements of the architecture manually, which risks introducing inconsistencies. This chapter provides an overview, comparison and detailed treatment of the various state-of-the-art approaches to describing and evolving software architectures. Furthermore, we discuss...... one particular framework named Tran SAT, which addresses the above problems of software architecture evolution. Tran SAT provides a new element in the software architecture descriptions language, called an architectural aspect, for describing new concerns and their integration into an existing...

  8. Evolution and Christian Faith

    Science.gov (United States)

    Roughgarden, J. E.

    2006-12-01

    My recent book, Evolution and Christian Faith explores how evolutionary biology can be portrayed from the religious perspective of Christianity. The principal metaphors for evolutionary biology---differential success at breeding and random mutation, probably originate with the dawn of agriculture and clearly occur in the Bible. The central narrative of evolutionary biology can be presented using Biblical passages, providing an account of evolution that is inherently friendly to a Christian perspective. Still, evolutionary biology is far from complete, and problematic areas pertain to species in which the concept of an individual is poorly defined, and to species in which the expression of gender and sexuality depart from Darwin's sexual-selection templates. The present- day controversy in the US about teaching evolution in the schools provides an opportunity to engage the public about science education.

  9. Lossless Conditional Schema Evolution

    DEFF Research Database (Denmark)

    Jensen, Ole Guttorm; Bøhlen, Michael Hanspeter

    2003-01-01

    The paper considers conditional schema evolution, where schema changes change the schema of the tuples that satisfy the change condition. When the schema of a relation change some tuples may no longer fit the current schema. Handling the mismatch between the intended schema of tuples and the reco......The paper considers conditional schema evolution, where schema changes change the schema of the tuples that satisfy the change condition. When the schema of a relation change some tuples may no longer fit the current schema. Handling the mismatch between the intended schema of tuples...... and the recorded schema of tuples is at the core of a DBMS that supports schema evolution. We propose to keep track of schema mismatches at the level of individual tuples, and prove that conditionally evolving schemas, in contrast to current commercial database systems, are lossless when the schema evolves...

  10. Cultural evolution and personalization

    CERN Document Server

    Xi, Ning; Zhang, Yi-Cheng

    2012-01-01

    In social sciences, there is currently no consensus on the mechanism for cultural evolution. The evolution of first names of newborn babies offers a remarkable example for the researches in the field. Here we perform statistical analyses on over 100 years of data in the United States. We focus in particular on how the frequency-rank distribution and inequality of baby names change over time. We propose a stochastic model where name choice is determined by personalized preference and social influence. Remarkably, variations on the strength of personalized preference can account satisfactorily for the observed empirical features. Therefore, we claim that personalization drives cultural evolution, at least in the example of baby names.

  11. Evolution and social epidemiology.

    Science.gov (United States)

    Nishi, Akihiro

    2015-11-01

    Evolutionary biology, which aims to explain the dynamic process of shaping the diversity of life, has not yet significantly affected thinking in social epidemiology. Current challenges in social epidemiology include understanding how social exposures can affect our biology, explaining the dynamics of society and health, and designing better interventions that are mindful of the impact of exposures during critical periods. I review how evolutionary concepts and tools, such as fitness gradient in cultural evolution, evolutionary game theory, and contemporary evolution in cancer, can provide helpful insights regarding social epidemiology.

  12. Emergence and Evolution

    DEFF Research Database (Denmark)

    Bullwinkle, Tammy J; Ibba, Michael

    2013-01-01

    ancestor and as such they provide insights into the evolution and development of the extant genetic code. Although the aaRSs have long been viewed as a highly conserved group of enzymes, findings within the last couple of decades have started to demonstrate how diverse and versatile these enzymes really...... are. Beyond their central role in translation, aaRSs and their numerous homologs have evolved a wide array of alternative functions both inside and outside translation. Current understanding of the emergence of the aaRSs, and their subsequent evolution into a functionally diverse enzyme family...

  13. TMDs: Evolution, modeling, precision

    CERN Document Server

    D'Alesio, Umberto; Melis, Stefano; Scimemi, Ignazio

    2014-01-01

    The factorization theorem for $q_T$ spectra in Drell-Yan processes, boson production and semi-inclusive deep inelastic scattering allows for the determination of the non-perturbative parts of transverse momentum dependent parton distribution functions. Here we discuss the fit of Drell-Yan and $Z$-production data using the transverse momentum dependent formalism and the resummation of the evolution kernel. We find a good theoretical stability of the results and a final $\\chi^2/{\\rm points}\\lesssim 1$. We show how the fixing of the non-perturbative pieces of the evolution can be used to make predictions at present and future colliders.

  14. TMDs: Evolution, modeling, precision

    Directory of Open Access Journals (Sweden)

    D’Alesio Umberto

    2015-01-01

    Full Text Available The factorization theorem for qT spectra in Drell-Yan processes, boson production and semi-inclusive deep inelastic scattering allows for the determination of the non-perturbative parts of transverse momentum dependent parton distribution functions. Here we discuss the fit of Drell-Yan and Z-production data using the transverse momentum dependent formalism and the resummation of the evolution kernel. We find a good theoretical stability of the results and a final χ2/points ≲ 1. We show how the fixing of the non-perturbative pieces of the evolution can be used to make predictions at present and future colliders.

  15. Controlled quantum evolutions

    CERN Document Server

    Petroni, N C; De Siena, S; Illuminati, F; Petroni, Nicola Cufaro; Martino, Salvatore De; Siena, Silvio De; Illuminati, Fabrizio

    1999-01-01

    We perform a detailed analysis of the non stationary solutions of the evolution (Fokker-Planck) equations associated to either stationary or non stationary quantum states by the stochastic mechanics. For the excited stationary states of quantum systems with singular velocity fields we explicitely discuss the exact solutions for the HO case. Moreover the possibility of modifying the original potentials in order to implement arbitrary evolutions ruled by these equations is discussed with respect to both possible models for quantum measurements and applications to the control of particle beams in accelerators.

  16. Teaching Evolution: From SMART Objectives to Threshold Experience

    Science.gov (United States)

    Wolf, Alexander; Akkaraju, Shylaja

    2014-01-01

    Despite the centrality of evolution to the study of biology, the pedagogical methods employed to teach the subject are often instructor-centered and rarely embedded in every topic throughout the curriculum. In addition, students' prior beliefs about evolution are often dismissed rather than incorporated into the classroom. In this article we…

  17. Evolution of Observation: Implementing Programmatic Change

    Science.gov (United States)

    Bender-Slack, Delane A.; Young, Teresa

    2013-01-01

    In the study reported, we examine the evolution of preservice teacher observation, focusing on the essential nature of observation to preservice teachers' learning about teaching while in the field. The study was 3 years long, and it involved 79 preservice teachers during semester-long language arts methods courses in early childhood and…

  18. Blind Equalization Based on Evolution Strategies

    Institute of Scientific and Technical Information of China (English)

    SongYu; ZhangXianda; 等

    1997-01-01

    Conventional blind equalization algorithms suffer from ill convergence to local minima and slow convergence speed.This paper proposes a novel blind equalization algorithm.using random search methods-evolution strategies and existing cost functions,Simulation results verify the fast and global convergence of the proposed algorithm.

  19. Relatedness, conflict, and the evolution of eusociality.

    Science.gov (United States)

    Liao, Xiaoyun; Rong, Stephen; Queller, David C

    2015-03-01

    The evolution of sterile worker castes in eusocial insects was a major problem in evolutionary theory until Hamilton developed a method called inclusive fitness. He used it to show that sterile castes could evolve via kin selection, in which a gene for altruistic sterility is favored when the altruism sufficiently benefits relatives carrying the gene. Inclusive fitness theory is well supported empirically and has been applied to many other areas, but a recent paper argued that the general method of inclusive fitness was wrong and advocated an alternative population genetic method. The claim of these authors was bolstered by a new model of the evolution of eusociality with novel conclusions that appeared to overturn some major results from inclusive fitness. Here we report an expanded examination of this kind of model for the evolution of eusociality and show that all three of its apparently novel conclusions are essentially false. Contrary to their claims, genetic relatedness is important and causal, workers are agents that can evolve to be in conflict with the queen, and eusociality is not so difficult to evolve. The misleading conclusions all resulted not from incorrect math but from overgeneralizing from narrow assumptions or parameter values. For example, all of their models implicitly assumed high relatedness, but modifying the model to allow lower relatedness shows that relatedness is essential and causal in the evolution of eusociality. Their modeling strategy, properly applied, actually confirms major insights of inclusive fitness studies of kin selection. This broad agreement of different models shows that social evolution theory, rather than being in turmoil, is supported by multiple theoretical approaches. It also suggests that extensive prior work using inclusive fitness, from microbial interactions to human evolution, should be considered robust unless shown otherwise.

  20. Evolution in Action

    Science.gov (United States)

    Dennis, Mike; Duggan, Adrienne; McGregor, Deb

    2014-01-01

    Evolution and inheritance appear in the new National Science Curriculum for England, which comes into effect from September 2014. In the curriculum documents, it is expected that pupils in year 6 (ages 10-11) should be taught to: (1) recognise that living things have changed over time; (2) recognise that living things produce offspring of the same…

  1. Evolution of subsidiary competences

    DEFF Research Database (Denmark)

    Geisler Asmussen, Christian; Pedersen, Torben; Dhanaraj, Charles

    of competitive advantage of nations, we hypothesize the contingencies under which heterogeneity in host environments influences subsidiary competence configuration. We test our model with data from more than 2,000 subsidiaries in seven Western European countries. Our results provide new insights on the evolution...

  2. Open-Ended Evolution

    DEFF Research Database (Denmark)

    Taylor, Tim; A. Bedau, Mark; Channon, Alastair

    2016-01-01

    This report describes the First Workshop on Open-Ended Evolution: Recent Progress and Future Milestones (OEE1), held during the ECAL 2015 conference at the University of York, U.K., in July 2015. We briefly summarise the content of the talks and discussions and the workshop, and provide links...

  3. Lossless conditional schema evolution

    DEFF Research Database (Denmark)

    Jensen, Ole Guttorm; Böhlen, Michael

    2004-01-01

    of a DBMS that supports schema evolution. We propose to keep track of schema mismatches at the level of individual tuples, and prove that evolving schemas with conditional schema changes, in contrast to database systems relying on data migration, are lossless when the schema evolves. The lossless property...

  4. Early cellular evolution.

    Science.gov (United States)

    Margulis, L.

    1972-01-01

    Study of the evolutionary developments that occurred subsequent to the origin of ancestral cells. Microbial physiology and ecology are potential sharp tools for shaping concepts of microbial evolution. Some popular unjustified assumptions are discussed. It is considered that certain principles derived mainly from the advances of molecular biology can be used to order the natural groups (genera) of extant prokaryotes and their patterns phylogenetically.

  5. Evolution Through Architectural Reconciliation

    NARCIS (Netherlands)

    Avgeriou, Paris; Guelfi, Nicolas; Perrouin, Gilles

    2005-01-01

    One of the possible scenarios in a system evolution cycle, is to translate an emergent set of new requirements into software architecture design and subsequently to update the system implementation. In this paper, we argue that this form of forward engineering, even though addresses the new system r

  6. EVOLUTION OF INSURANCE DEFINITION

    Directory of Open Access Journals (Sweden)

    V. A. Gorb

    2011-03-01

    Full Text Available In the article the evolution of the concept of insurance from the earliest forms to contemporary ones is shown. The development of insurance in Ukraine is demonstrated. A review of transformation of the insurance concept is presented in tabular form.

  7. Evolution and Flow.

    Science.gov (United States)

    Csikszentmihalyi, Mihaly

    1997-01-01

    Presents flow theory in the context of evolution. Defines the elements of "flow" and contends that flow results in an optimal state of inner harmony which improves one's chance for survival. Identifies consequences of flow for creativity, peak performance, talent development, productivity, self-esteem, and stress reduction. Examines the…

  8. Darwinism: Evolution or Revolution?

    Science.gov (United States)

    Holt, Niles R.

    1989-01-01

    Maintains that Darwin's theory of evolution was more than a science versus religion debate; rather it was a revolutionary concept that influenced numerous social and political ideologies and movements throughout western history. Traces the impact of Darwin's work historically, utilizing a holistic approach. (RW)

  9. Evolution of rhizobium symbiosis

    NARCIS (Netherlands)

    Camp, Op den R.H.M.

    2012-01-01

    The evolution of rhizobium symbiosis is studied from several points of view in this thesis. The ultimate goal of the combined approaches is to unravel the genetic constrains of the symbiotic interaction. To this end the legume rhizobium symbiosis is studied in model plant species from the Papilionoi

  10. Evolution 2.0

    DEFF Research Database (Denmark)

    Andersen, Casper; Bek-Thomsen, Jakob; Clasen, Mathias

    2013-01-01

    Studies in the history of science and education have documented that the reception and understanding of evolutionary theory is highly contingent on local factors such as school systems, cultural traditions, religious beliefs, and language. This has important implications for teaching evolution...

  11. Evolution Perception with Metaphors

    Science.gov (United States)

    Yilmaz, Fatih

    2016-01-01

    The main objective of this research is to find out how the teacher candidates who graduated from the Faculty of Theology and study in pedagogical formation program perceive the theory of evolution. Having a descriptive characteristic, this research is conducted with 63 Faculty of Theology graduate teacher candidates of which 36 is women and 27 is…

  12. Software Architecture Evolution

    Science.gov (United States)

    Barnes, Jeffrey M.

    2013-01-01

    Many software systems eventually undergo changes to their basic architectural structure. Such changes may be prompted by new feature requests, new quality attribute requirements, changing technology, or other reasons. Whatever the causes, architecture evolution is commonplace in real-world software projects. Today's software architects, however,…

  13. Methods and Systems for Measurement and Estimation of Normalized Contrast in Infrared Thermography

    Science.gov (United States)

    Koshti, Ajay M. (Inventor)

    2015-01-01

    Methods and systems for converting an image contrast evolution of an object to a temperature contrast evolution and vice versa are disclosed, including methods for assessing an emissivity of the object; calculating an afterglow heat flux evolution; calculating a measurement region of interest temperature change; calculating a reference region of interest temperature change; calculating a reflection temperature change; calculating the image contrast evolution or the temperature contrast evolution; and converting the image contrast evolution to the temperature contrast evolution or vice versa, respectively.

  14. Dislocation evolution with rheological forming of metal

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    It is known that some internal defects exist in metal materials. Preliminary attempt to relate dislo cation evolution with metal rheological forming was done. By the attempt, it is learned that the evolution of dislocation density p( x, y, t ) is essentially the change of n independent internal variables qα (α = 1, 2, …n ) with material. The preliminary research in theory and experiments showed that dislocations piling-up could be avoided. One can improve the internal microstructure and mechanical properties of products by rheological forming method.

  15. Kinetics of oxygen evolution of dark-adapted plant leaves I.Kinetics of oxygen evolution determined by photoacoustic method%植物暗适应叶的放氧动力学(Ⅰ) --光声放氧动力学

    Institute of Scientific and Technical Information of China (English)

    樊大勇; 高荣孚

    2001-01-01

    When a dark-adapted leaf is reilluminated, fast and complexphotoacoustic transients of oxygen evolution can be observed by photoacoustic technique, a phenomenon called "oxygen gush" appeared, but the underlying mechanism unclear. A study on the photoacoustic transients of oxygen evolution of spinach leaves during the light induction period was carried out, by a self-made photoacoustic spectrometer. The effects of different dark-adapted time, preilluminating far-red light and saturated light, high CO2 concentration on the "oxygen gush" were studied, including the relationship between the photoacoustic heat and oxygen evolution. It is proposed that the oxygen gush is composed of two components, it's kinetics might reflect the state and activity of PSⅡ%用光声光谱仪检测结果表明,暗适应叶在光诱导期间出现非常复杂的光声瞬态放氧,产生了一种称为氧峰(oxygengush)的现象.该文利用自制的光声仪对暗适应菠菜叶在光诱导期间出现的光声瞬态放氧与暗适应时间关系,远红光、饱和光预处理以及高浓度CO2对光声瞬态放氧的影响,光声热信号与光声放氧信号之间的关系作了初步研究.推测由两个组分组成的氧峰与其动力学可能反映光系统Ⅱ的状态.

  16. Modeling Network Evolution Using Graph Motifs

    CERN Document Server

    Conway, Drew

    2011-01-01

    Network structures are extremely important to the study of political science. Much of the data in its subfields are naturally represented as networks. This includes trade, diplomatic and conflict relationships. The social structure of several organization is also of interest to many researchers, such as the affiliations of legislators or the relationships among terrorist. A key aspect of studying social networks is understanding the evolutionary dynamics and the mechanism by which these structures grow and change over time. While current methods are well suited to describe static features of networks, they are less capable of specifying models of change and simulating network evolution. In the following paper I present a new method for modeling network growth and evolution. This method relies on graph motifs to generate simulated network data with particular structural characteristic. This technique departs notably from current methods both in form and function. Rather than a closed-form model, or stochastic ...

  17. Hardware Evolution of Control Electronics

    Science.gov (United States)

    Gwaltney, David; Steincamp, Jim; Corder, Eric; King, Ken; Ferguson, M. I.; Dutton, Ken

    2003-01-01

    The evolution of closed-loop motor speed controllers implemented on the JPL FPTA2 is presented. The response of evolved controller to sinusoidal commands, controller reconfiguration for fault tolerance,and hardware evolution are described.

  18. Reconstructing cetacean brain evolution using computed tomography.

    Science.gov (United States)

    Marino, Lori; Uhen, Mark D; Pyenson, Nicholas D; Frohlich, Bruno

    2003-05-01

    Until recently, there have been relatively few studies of brain mass and morphology in fossil cetaceans (dolphins, whales, and porpoises) because of difficulty accessing the matrix that fills the endocranial cavity of fossil cetacean skulls. As a result, our knowledge about cetacean brain evolution has been quite limited. By applying the noninvasive technique of computed tomography (CT) to visualize, measure, and reconstruct the endocranial morphology of fossil cetacean skulls, we can gain vastly more information at an unprecedented rate about cetacean brain evolution. Here, we discuss our method and demonstrate it with several examples from our fossil cetacean database. This approach will provide new insights into the little-known evolutionary history of cetacean brain evolution.

  19. The evolution of piecewise polynomial wave functions

    Science.gov (United States)

    Andrews, Mark

    2017-01-01

    For a non-relativistic particle, we consider the evolution of wave functions that consist of polynomial segments, usually joined smoothly together. These spline wave functions are compact (that is, they are initially zero outside a finite region), but they immediately extend over all available space as they evolve. The simplest splines are the square and triangular wave functions in one dimension, but very complicated splines have been used in physics. In general the evolution of such spline wave functions can be expressed in terms of antiderivatives of the propagator; in the case of a free particle or an oscillator, all the evolutions are expressed exactly in terms of Fresnel integrals. Some extensions of these methods to two and three dimensions are discussed.

  20. Dynamical evolution of two associated galactic bars

    CERN Document Server

    Garzon, F

    2014-01-01

    We study the dynamical interactions of mass systems in equilibrium under their own gravity that mutually exert and experience gravitational forces. The method we employ is to model the dynamical evolution of two isolated bars, hosted within the same galactic system, under their mutual gravitational interaction. In this study we present an analytical treatment of the secular evolution of two bars that oscillate with respect one another. Two cases of interaction, with and without geometrical deformation, are discussed. In the latter case, the bars are described as modified Jacobi ellipsoids. These triaxial systems are formed by a rotating fluid mass in gravitational equilibrium with its own rotational velocity and the gravitational field of the other bar. The governing equation for the variation of their relative angular separation is then numerically integrated, which also provides the time evolution of the geometrical parameters of the bodies. The case of rigid, non-deformable, bars produces in some cases an ...

  1. The tempo and mode of barnacle evolution

    DEFF Research Database (Denmark)

    Pérez-Losada, Marcos; Harp, Margaret; Høeg, Jens T

    2008-01-01

    (outgroup) species representing almost all the Thoracica families to assess the tempo and mode of barnacle evolution. Using phylogenetic methods of maximum parsimony, maximum likelihood, and Bayesian inference and 14 fossil calibrations, we found that: (1) Iblomorpha form a monophyletic group; (2......) pedunculated barnacles without shell plates (Heteralepadomorpha) are not ancestral, but have evolved, at least twice, from plated forms; (3) the ontogenetic pattern with 5-->6-->8-->12+ plates does not reflect Thoracica shell evolution; (4) the traditional asymmetric barnacles (Verrucidae) and the Balanomorpha......) the Thoracica suborders evolved since the Early Carboniferous (340mya) with the final radiation of the Sessilia in the Upper Jurassic (147mya). These results, therefore, reject many of the underlying hypotheses about character evolution in the Cirripedia Thoracica, stimulate a variety of new thoughts...

  2. Unpolarized coupled DGLAP evolution equation at small-

    Indian Academy of Sciences (India)

    Saurav Bhattacharjee; Ranjit Baishya; Jayanata Kumar Sarma

    2013-01-01

    In this paper, we have obtained the solution of the unpolarized coupled Dokshitzer–Gribove–Lipatov–Alterelli–Parisi (DGLAP) evolution equation in leading order at the small- limit. Here, we have used a Taylor series expansion, separation of functions and then the method of characteristics to solve the evolution equations. We have also calculated -evolution of singlet and gluon distribution functions and the results are compared with E665 and NNPDF data for singlet structure function and GRV1998 and MRST2004 gluon parametrizations. It is shown that our results are in good agreement with the parametrizations especially at small-x and high-2 region. From global parametrizations and our results, we have seen that the singlet and gluon distribution functions increase when 2 increases for fixed values of .

  3. Directed Evolution of Enzymes for Industrial Biocatalysis.

    Science.gov (United States)

    Porter, Joanne L; Rusli, Rukhairul A; Ollis, David L

    2016-02-01

    Enzymes have the potential to catalyse a wide variety of chemical reactions. They are increasingly being sought as environmentally friendly and cost-effective alternatives to conventional catalysts used in industries ranging from bioremediation to applications in medicine and pharmaceutics. Despite the benefits, they are not without their limitations. Many naturally occurring enzymes are not suitable for use outside of their native cellular environments. However, protein engineering can be used to generate enzymes tailored for specific industrial applications. Directed evolution is particularly useful and can be employed even when lack of structural information impedes the use of rational design. The aim of this review is to provide an overview of current industrial applications of enzyme technology and to show how directed evolution can be used to modify and to enhance enzyme properties. This includes a brief discussion on library generation and a more detailed focus on library screening methods, which are critical to any directed evolution experiment.

  4. Measuring multiple evolution mechanisms of complex networks.

    Science.gov (United States)

    Zhang, Qian-Ming; Xu, Xiao-Ke; Zhu, Yu-Xiao; Zhou, Tao

    2015-01-01

    Numerous concise models such as preferential attachment have been put forward to reveal the evolution mechanisms of real-world networks, which show that real-world networks are usually jointly driven by a hybrid mechanism of multiplex features instead of a single pure mechanism. To get an accurate simulation for real networks, some researchers proposed a few hybrid models by mixing multiple evolution mechanisms. Nevertheless, how a hybrid mechanism of multiplex features jointly influence the network evolution is not very clear. In this study, we introduce two methods (link prediction and likelihood analysis) to measure multiple evolution mechanisms of complex networks. Through tremendous experiments on artificial networks, which can be controlled to follow multiple mechanisms with different weights, we find the method based on likelihood analysis performs much better and gives very accurate estimations. At last, we apply this method to some real-world networks which are from different domains (including technology networks and social networks) and different countries (e.g., USA and China), to see how popularity and clustering co-evolve. We find most of them are affected by both popularity and clustering, but with quite different weights.

  5. Directed evolution: tailoring biocatalysts for industrial applications.

    Science.gov (United States)

    Kumar, Ashwani; Singh, Suren

    2013-12-01

    Current challenges and promises of white biotechnology encourage protein engineers to use a directed evolution approach to generate novel and useful biocatalysts for various sets of applications. Different methods of enzyme engineering have been used in the past in an attempt to produce enzymes with improved functions and properties. Recent advancement in the field of random mutagenesis, screening, selection and computational design increased the versatility and the rapid development of enzymes under strong selection pressure with directed evolution experiments. Techniques of directed evolution improve enzymes fitness without understanding them in great detail and clearly demonstrate its future role in adapting enzymes for use in industry. Despite significant advances to date regarding biocatalyst improvement, there still remains a need to improve mutagenesis strategies and development of easy screening and selection tools without significant human intervention. This review covers fundamental and major development of directed evolution techniques, and highlights the advances in mutagenesis, screening and selection methods with examples of enzymes developed by using these approaches. Several commonly used methods for creating molecular diversity with their advantages and disadvantages including some recently used strategies are also discussed.

  6. Jet quenching from QCD evolution

    Science.gov (United States)

    Chien, Yang-Ting; Emerman, Alexander; Kang, Zhong-Bo; Ovanesyan, Grigory; Vitev, Ivan

    2016-04-01

    Recent advances in soft-collinear effective theory with Glauber gluons have led to the development of a new method that gives a unified description of inclusive hadron production in reactions with nucleons and heavy nuclei. We show how this approach, based on the generalization of the DGLAP evolution equations to include final-state medium-induced parton shower corrections for large Q2 processes, can be combined with initial-state effects for applications to jet quenching phenomenology. We demonstrate that the traditional parton energy loss calculations can be regarded as a special soft-gluon emission limit of the general QCD evolution framework. We present phenomenological comparison of the SCETG -based results on the suppression of inclusive charged hadron and neutral pion production in √{sNN }=2.76 TeV lead-lead collisions at the Large Hadron Collider to experimental data. We also show theoretical predictions for the upcoming √{sNN }≃5.1 TeV Pb +Pb run at the LHC.

  7. Mulla Sadra and Evolution Theory

    Directory of Open Access Journals (Sweden)

    ALI ARSHAD RIAHI

    2015-12-01

    Full Text Available In their observations, contemporary scientists have believed in transformism which claims whole natural world is always in evolvement. This paper investigates whether Mulla Sadra’s philosophical opinions are consistent with this theory or not. The method of this research is analytical-descriptive. The conclusion is that four fundamentals: the principality of existence, the analogical unity of existence, the substantial movement and gradual increase in intensity of existence, are the main foundations of Mulla Sadra’s philosophy. The first three principles justify the forth one which is ‘the evolutional movement of the natural creatures’. According to Mulla Sadra, nature is in-itself a movement and movement is not limited to accident, but he believes that movement is the mood of the nature. He believes that nature is, therefore, a continuous whole that moves from its inferiority to its superiority, in the same way as a child grows. In this paper it is also proved that the evolution of the creatures does not contradict the existence of God and religious texts.

  8. Information-theoretic metamodel of organizational evolution

    Science.gov (United States)

    Sepulveda, Alfredo

    2011-12-01

    Social organizations are abstractly modeled by holarchies---self-similar connected networks---and intelligent complex adaptive multiagent systems---large networks of autonomous reasoning agents interacting via scaled processes. However, little is known of how information shapes evolution in such organizations, a gap that can lead to misleading analytics. The research problem addressed in this study was the ineffective manner in which classical model-predict-control methods used in business analytics attempt to define organization evolution. The purpose of the study was to construct an effective metamodel for organization evolution based on a proposed complex adaptive structure---the info-holarchy. Theoretical foundations of this study were holarchies, complex adaptive systems, evolutionary theory, and quantum mechanics, among other recently developed physical and information theories. Research questions addressed how information evolution patterns gleamed from the study's inductive metamodel more aptly explained volatility in organization. In this study, a hybrid grounded theory based on abstract inductive extensions of information theories was utilized as the research methodology. An overarching heuristic metamodel was framed from the theoretical analysis of the properties of these extension theories and applied to business, neural, and computational entities. This metamodel resulted in the synthesis of a metaphor for, and generalization of organization evolution, serving as the recommended and appropriate analytical tool to view business dynamics for future applications. This study may manifest positive social change through a fundamental understanding of complexity in business from general information theories, resulting in more effective management.

  9. Mapping the evolution of scientific ideas

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, David C [Los Alamos National Laboratory; Herrera, Mark [UNIV OF MARYLAND; Gulbahce, Natali [NORTHEASTERN UNIV

    2008-01-01

    The importance of interdisciplinary research is ever increasing as challenging world problems require expertise across diverse fields. Despite the apparent conceptual boundaries of scientific fields, a formal description for their evolution is lacking. Here we describe a novel approach to study the dynamics and evolution of scientific ideas and fields using a network-based analysis. We build a idea network consisting of American Physical Society Pacs numbers as nodes representing scientific concepts. Two Pacs numbers are linked in the network if there exist publications that reference them simultaneously. We locate scientific fields using an overlapping community finding algorithm and describe the time evolution of these fields using a community evolution method over the course of 1985-2006. We find that the communities we find map to scientific fields, the lifetime of these fields strongly depends on their size, impact and activity, and longest living communities are least volatile. The described approach to quantify the evolution of ideas is expected to be relevant in making predictions about the future of science and how to guide its development.

  10. Mapping the evolution of scientific ideas

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, David [Los Alamos National Laboratory; Herrera, Mark [UNIV OF MARYLAND; Gulbahce, Natali [UNIV OF BOSTON

    2009-01-01

    Despite the apparent conceptual boundaries of scientific fields, a formal description for their evolution is lacking. Here we describe a novel approach to study the dynamics and evolution of scientific fields using a network-based analysis. We build an idea network consisting of American Physical Society PACS numbers as nodes representing scientific concepts. Two PACS numbers are linked if there exist publications that reference them simultaneously. We locate scientific fields using Cfinder, an overlapping community finding algorithm, and describe the time evolution of these fields using a community evolution method over the course of 1985-2006. The communities we identify map to known scientific fields, and their age strongly depends on t.heir size, impact and activity. Our analysis further suggests that communities that redefine themselves by merging and creating new groups of ideas tend to have more fitness as measured by the impact per paper, and hence communities with a higher fitness tend to be short-lived. The described approach to quantify the evolution of ideas may be relevant in making predictions about the future of science and how to guide its development.

  11. Component evolution in general random intersection graphs

    Energy Technology Data Exchange (ETDEWEB)

    Bradonjic, Milan [Los Alamos National Laboratory; Hagberg, Aric [Los Alamos National Laboratory; Hengartner, Nick [Los Alamos National Laboratory; Percus, Allon G [CLAREMONT GRADUATE UNIV.

    2010-01-01

    We analyze component evolution in general random intersection graphs (RIGs) and give conditions on existence and uniqueness of the giant component. Our techniques generalize the existing methods for analysis on component evolution in RIGs. That is, we analyze survival and extinction properties of a dependent, inhomogeneous Galton-Watson branching process on general RIGs. Our analysis relies on bounding the branching processes and inherits the fundamental concepts from the study on component evolution in Erdos-Renyi graphs. The main challenge becomes from the underlying structure of RIGs, when the number of offsprings follows a binomial distribution with a different number of nodes and different rate at each step during the evolution. RIGs can be interpreted as a model for large randomly formed non-metric data sets. Besides the mathematical analysis on component evolution, which we provide in this work, we perceive RIGs as an important random structure which has already found applications in social networks, epidemic networks, blog readership, or wireless sensor networks.

  12. New thinking: the evolution of human cognition.

    Science.gov (United States)

    Heyes, Cecilia

    2012-08-05

    Humans are animals that specialize in thinking and knowing, and our extraordinary cognitive abilities have transformed every aspect of our lives. In contrast to our chimpanzee cousins and Stone Age ancestors, we are complex political, economic, scientific and artistic creatures, living in a vast range of habitats, many of which are our own creation. Research on the evolution of human cognition asks what types of thinking make us such peculiar animals, and how they have been generated by evolutionary processes. New research in this field looks deeper into the evolutionary history of human cognition, and adopts a more multi-disciplinary approach than earlier 'Evolutionary Psychology'. It is informed by comparisons between humans and a range of primate and non-primate species, and integrates findings from anthropology, archaeology, economics, evolutionary biology, neuroscience, philosophy and psychology. Using these methods, recent research reveals profound commonalities, as well striking differences, between human and non-human minds, and suggests that the evolution of human cognition has been much more gradual and incremental than previously assumed. It accords crucial roles to cultural evolution, techno-social co-evolution and gene-culture co-evolution. These have produced domain-general developmental processes with extraordinary power-power that makes human cognition, and human lives, unique.

  13. Elementary evolutions in Banach algebra

    OpenAIRE

    Lindsay, J. Martin; Das, Bata Krishna

    2013-01-01

    An elementary class of evolutions in unital Banach algebras is obtained by integrating product functions over Guichardet's symmetric measure space on the half-line. These evolutions, along with a useful subclass, are characterised and a Lie-Trotter product formula is proved. The class is rich enough to form the basis for a recent approach to quantum stochastic evolutions.

  14. Expanding the Understanding of Evolution

    Science.gov (United States)

    Musante, Susan

    2011-01-01

    Originally designed for K-12 teachers, the Understanding Evolution (UE) Web site ("www.understandingevolution.org") is a one-stop shop for all of a teacher's evolution education needs, with lesson plans, teaching tips, lists of common evolution misconceptions, and much more. However, during the past five years, the UE project team learned that…

  15. Fla. Panel's Evolution Vote Hailed

    Science.gov (United States)

    Cavanagh, Sean

    2008-01-01

    This article reports on how the compromise hammered out in Florida recently over the treatment of evolution in the state's science classrooms is winning praise from scientists and educators. The new science standards will refer to evolution as the "scientific theory of evolution." These changes will replace more-general language in the previous…

  16. Fla. Panel's Evolution Vote Hailed

    Science.gov (United States)

    Cavanagh, Sean

    2008-01-01

    This article reports on how the compromise hammered out in Florida recently over the treatment of evolution in the state's science classrooms is winning praise from scientists and educators. The new science standards will refer to evolution as the "scientific theory of evolution." These changes will replace more-general language in the…

  17. Evolution of Brain and Language

    Science.gov (United States)

    Schoenemann, P. Thomas

    2009-01-01

    The evolution of language and the evolution of the brain are tightly interlinked. Language evolution represents a special kind of adaptation, in part because language is a complex behavior (as opposed to a physical feature) but also because changes are adaptive only to the extent that they increase either one's understanding of others, or one's…

  18. Kamikazes and cultural evolution.

    Science.gov (United States)

    Allen-Hermanson, Sean

    2017-02-01

    Is cultural evolution needed to explain altruistic selfsacrifice? Some contend that cultural traits (e.g. beliefs, behaviors, and for some "memes") replicate according to selection processes that have "floated free" from biology. One test case is the example of suicide kamikaze attacks in wartime Japan. Standard biological mechanisms-such as reciprocal altruism and kin selection-might not seem to apply here: The suicide pilots did not act on the expectation that others would reciprocate, and they were supposedly sacrificing themselves for country and emperor, not close relatives. Yet an examination of both the historical record and the demands of evolutionary theory suggest the kamikaze phenomenon does not cry out for explanation in terms of a special non-biological selection process. This weakens the case for cultural evolution, and has interesting implications for our understanding of altruistic self-sacrifice.

  19. Environment and Protostellar Evolution

    CERN Document Server

    Zhang, Yichen

    2014-01-01

    Even today in our Galaxy, stars form from gas cores in a variety of environments, which may affect the properties of resulting star and planetary systems. Here we study the role of pressure, parameterized via ambient clump mass surface density, on protostellar evolution and appearance, focussing on low-mass, Sun-like stars and considering a range of conditions from relatively low pressure filaments in Taurus, to intermediate pressures of cluster-forming clumps like the Orion Nebula Cluster (ONC), to very high pressures that may be found in the densest Infrared Dark Clouds (IRDCs) or in the Galactic Center (GC). We present unified analytic and numerical models for collapse of prestellar cores, accretion disks, protostellar evolution and bipolar outflows, coupled to radiative transfer (RT) calculations and a simple astrochemical model to predict CO gas phase abundances. Prestellar cores in high pressure environments are smaller and denser and thus collapse with higher accretion rates and efficiencies, resulting...

  20. QCD Evolution Workshop

    CERN Document Server

    2015-01-01

    These are the proceedings of the QCD Evolution 2015 Workshop which was held 26–30 May, 2015 at Jefferson Lab, Newport News, Virginia, USA. The workshop is a continuation of a series of workshops held during four consecutive years 2011, 2012, 2013 at Jefferson Lab, and in 2014 in Santa Fe, NM. With the rapid developments in our understanding of the evolution of parton distributions including low-x, TMDs, GPDs, higher-twist correlation functions, and the associated progress in perturbative QCD, lattice QCD and effective field theory techniques we look forward with great enthusiasm to the 2015 meeting. A special attention was also paid to participation of experimentalists as the topics discussed are of immediate importance for the JLab 12 experimental program and a future Electron Ion Collider.

  1. Evolution of clustered storage

    CERN Document Server

    CERN. Geneva; Van de Vyvre, Pierre

    2007-01-01

    The session actually featured two presentations: * Evolution of clustered storage by Lance Hukill, Quantum Corporation * ALICE DAQ - Usage of a Cluster-File System: Quantum StorNext by Pierre Vande Vyvre, CERN-PH the second one prepared at short notice by Pierre (thanks!) to present how the Quantum technologies are being used in the ALICE experiment. The abstract to Mr Hukill's follows. Clustered Storage is a technology that is driven by business and mission applications. The evolution of Clustered Storage solutions starts first at the alignment between End-users needs and Industry trends: * Push-and-Pull between managing for today versus planning for tomorrow * Breaking down the real business problems to the core applications * Commoditization of clients, servers, and target devices * Interchangeability, Interoperability, Remote Access, Centralized control * Oh, and yes, there is a budget and the "real world" to deal with This presentation will talk through these needs and trends, and then ask the question, ...

  2. Evolution of mycorrhiza systems

    Science.gov (United States)

    Cairney, J. W. G.

    Most terrestrial plants live in mutualistic symbiosis with root-infecting mycorrhizal fungi. Fossil records and molecular clock dating suggest that all extant land plants have arisen from an ancestral arbuscular mycorrhizal condition. Arbuscular mycorrhizas evolved concurrently with the first colonisation of land by plants some 450-500 million years ago and persist in most extant plant taxa. Ectomycorrhizas (about 200million years ago) and ericoid mycorrhizas (about 100million years ago) evolved subsequently as the organic matter content of some ancient soils increased and sclerophyllous vegetation arose as a response to nutrient-poor soils respectively. Mycorrhizal associations appear to be the result of relatively diffuse coevolutionary processes. While early events in the evolution of mycorrhizal symbioses may have involved reciprocal genetic changes in ancestral plants and free-living fungi, available evidence points largely to ongoing parallel evolution of the partners in response to environmental change.

  3. Anatomy of Scientific Evolution

    CERN Document Server

    Yun, Jinhyuk; Jeong, Hawoong

    2014-01-01

    The quest for historically impactful science and technology provides invaluable insight into the innovation dynamics of human society, yet many studies are limited to qualitative and small-scale approaches. Here, we investigate scientific evolution through systematic analysis of a massive corpus of digitized English texts between 1800 and 2008. Our analysis reveals remarkable predictability for long-prevailing scientific concepts based on the levels of their prior usage. Interestingly, once a threshold of early adoption rates is passed even slightly, scientific concepts can exhibit sudden leaps in their eventual lifetimes. We developed a mechanistic model to account for such results, indicating that slowly-but-commonly adopted science and technology surprisingly tend to have higher innate strength than fast-and-commonly adopted ones. The model prediction for disciplines other than science was also well verified. Our approach sheds light on unbiased and quantitative analysis of scientific evolution in society,...

  4. The evolution of helicopters

    Science.gov (United States)

    Chen, R.; Wen, C. Y.; Lorente, S.; Bejan, A.

    2016-07-01

    Here, we show that during their half-century history, helicopters have been evolving into geometrically similar architectures with surprisingly sharp correlations between dimensions, performance, and body size. For example, proportionalities emerge between body size, engine size, and the fuel load. Furthermore, the engine efficiency increases with the engine size, and the propeller radius is roughly the same as the length scale of the whole body. These trends are in accord with the constructal law, which accounts for the engine efficiency trend and the proportionality between "motor" size and body size in animals and vehicles. These body-size effects are qualitatively the same as those uncovered earlier for the evolution of aircraft. The present study adds to this theoretical body of research the evolutionary design of all technologies [A. Bejan, The Physics of Life: The Evolution of Everything (St. Martin's Press, New York, 2016)].

  5. Managing Software Process Evolution

    DEFF Research Database (Denmark)

    This book focuses on the design, development, management, governance and application of evolving software processes that are aligned with changing business objectives, such as expansion to new domains or shifting to global production. In the context of an evolving business world, it examines...... the complete software process lifecycle, from the initial definition of a product to its systematic improvement. In doing so, it addresses difficult problems, such as how to implement processes in highly regulated domains or where to find a suitable notation system for documenting processes, and provides...... essential insights and tips to help readers manage process evolutions. And last but not least, it provides a wealth of examples and cases on how to deal with software evolution in practice. Reflecting these topics, the book is divided into three parts. Part 1 focuses on software business transformation...

  6. Characteristic Evolution and Matching

    Directory of Open Access Journals (Sweden)

    Winicour Jeffrey

    2009-04-01

    Full Text Available I review the development of numerical evolution codes for general relativity based upon the characteristic initial value problem. Progress is traced from the early stage of 1D feasibility studies to 2D axisymmetric codes that accurately simulate the oscillations and gravitational collapse of relativistic stars and to current 3D codes that provide pieces of a binary black hole spacetime. Cauchy codes have now been successful at simulating all aspects of the binary black hole problem inside an artificially constructed outer boundary. A prime application of characteristic evolution is to eliminate the role of this artificial outer boundary via Cauchy-characteristic matching, by which the radiated waveform can be computed at null infinity. Progress in this direction is discussed.

  7. Education and Evolution

    DEFF Research Database (Denmark)

    Hjermitslev, Hans Henrik

    2015-01-01

    known foreign thinkers in the general public at the time of his death in 1903. Moreover, in the decades around 1900 Spencer’s thoughts on education were part of the curricula at many colleges of education. Spencer’s ideas on evolution and education were thus widely circulated and positively received...... and in discussing the philosophical consequences of an evolutionary worldview. In the late 1870s and 1880s several of Spencer’s works were translated into Danish and Swedish and he became a household name among liberal intellectuals who primarily discussed his views on education and evolution. His most influential...... and widespread work in Scandinavia was Education from 1861. It was translated into Danish in 1876, into Swedish in 1883 and into Norwegian in 1900. Parts of his works on sociology, ethics and philosophy were also translated into the Scandinavian languages, and a new generation of university professors...

  8. Galactic Chemical Evolution

    CERN Document Server

    Gibson, B K; Renda, A; Kawata, D; Lee, H; Gibson, Brad K.; Fenner, Yeshe; Renda, Agostino; Kawata, Daisuke; Lee, Hyun-chul

    2003-01-01

    The primary present-day observables upon which theories of galaxy evolution are based are a system's morphology, dynamics, colour, and chemistry. Individually, each provides an important constraint to any given model; in concert, the four represent a fundamental (intractable) boundary condition for chemodynamical simulations. We review the current state-of-the-art semi-analytical and chemodynamical models for the Milky Way, emphasising the strengths and weaknesses of both approaches.

  9. Software evolution and maintenance

    CERN Document Server

    Tripathy, Priyadarshi

    2014-01-01

    Software Evolution and Maintenance: A Practitioner's Approach is an accessible textbook for students and professionals, which collates the advances in software development and provides the most current models and techniques in maintenance.Explains two maintenance standards: IEEE/EIA 1219 and ISO/IEC14764Discusses several commercial reverse and domain engineering toolkitsSlides for instructors are available onlineInformation is based on the IEEE SWEBOK (Software Engineering Body of Knowledge)

  10. Evolution of Social networks

    OpenAIRE

    Hellmann, Tim; Staudigl, Mathias

    2012-01-01

    Modeling the evolution of networks is central to our understanding of modern large communication systems, such as theWorld-Wide-Web, as well as economic and social networks. The research on social and economic networks is truly interdisciplinary and the number of modeling strategies and concepts is enormous. In this survey we present some modeling approaches, covering classical random graph models and game-theoretic models, which may be used to provide a unified framework to model and analyze...

  11. Viral quasispecies evolution

    OpenAIRE

    Domingo, Esteban; Sheldon, Julie; Perales, Celia

    2012-01-01

    Summary: Evolution of RNA viruses occurs through disequilibria of collections of closely related mutant spectra or mutant clouds termed viral quasispecies. Here we review the origin of the quasispecies concept and some biological implications of quasispecies dynamics. Two main aspects are addressed: (i) mutant clouds as reservoirs of phenotypic variants for virus adaptability and (ii) the internal interactions that are established within mutant spectra that render a virus ensemble the unit of...

  12. Small asteroid system evolution

    OpenAIRE

    Jacobson, Seth A.

    2014-01-01

    Observations with radar, photometric and direct imaging techniques have discovered that multiple asteroid systems can be divided clearly into a handful of different morphologies, and recently, the discovery of small unbound asteroid systems called asteroid pairs have revolutionized the study of small asteroid systems. Simultaneously, new theoretical advances have demonstrated that solar radiation dictates the evolution of small asteroids with strong implications for asteroid internal structur...

  13. Entrepreneurship, Evolution and Geography

    OpenAIRE

    Stam, Erik

    2009-01-01

    Entrepreneurship is a fundamental driver of economic evolution. It is also a distinctly spatially uneven process, and thus an important explanation of the uneven economic development of regions and nations. Not surprisingly, entrepreneurship is a key element of evolutionary economics (Schumpeter 1934; Witt 1998; Grebel et al. 2003; Metcalfe 2004; Grebel 2007) and has been recognized as an important element in explaining (regional) economic development (Acs and Armington 2004; Audretsch et al....

  14. Consciousness and biological evolution.

    Science.gov (United States)

    Lindahl, B I

    1997-08-21

    It has been suggested that if the preservation and development of consciousness in the biological evolution is a result of natural selection, it is plausible that consciousness not only has been influenced by neural processes, but has had a survival value itself; and it could only have had this, if it had also been efficacious. This argument for mind-brain interaction is examined, both as the argument has been developed by William James and Karl Popper and as it has been discussed by C.D. Broad. The problem of identifying mental phenomena with certain neural phenomena is also addressed. The main conclusion of the analysis is that an explanation of the evolution of consciousness in Darwinian terms of natural selection does not rule out that consciousness may have evolved as a mere causally inert effect of the evolution of the nervous system, or that mental phenomena are identical with certain neural phenomena. However, the interactionistic theory still seems, more plausible and more fruitful for other reasons brought up in the discussion.

  15. Darwinian Evolution and Fractals

    Science.gov (United States)

    Carr, Paul H.

    2009-05-01

    Did nature's beauty emerge by chance or was it intelligently designed? Richard Dawkins asserts that evolution is blind aimless chance. Michael Behe believes, on the contrary, that the first cell was intelligently designed. The scientific evidence is that nature's creativity arises from the interplay between chance AND design (laws). Darwin's ``Origin of the Species,'' published 150 years ago in 1859, characterized evolution as the interplay between variations (symbolized by dice) and the natural selection law (design). This is evident in recent discoveries in DNA, Madelbrot's Fractal Geometry of Nature, and the success of the genetic design algorithm. Algorithms for generating fractals have the same interplay between randomness and law as evolution. Fractal statistics, which are not completely random, characterize such phenomena such as fluctuations in the stock market, the Nile River, rainfall, and tree rings. As chaos theorist Joseph Ford put it: God plays dice, but the dice are loaded. Thus Darwin, in discovering the evolutionary interplay between variations and natural selection, was throwing God's dice!

  16. Evolution of segmented strings

    CERN Document Server

    Gubser, Steven S

    2016-01-01

    I explain how to evolve segmented strings in de Sitter and anti-de Sitter spaces of any dimension in terms of forward-directed null displacements. The evolution is described entirely in terms of discrete hops which do not require a continuum spacetime. Moreover, the evolution rule is purely algebraic, so it can be defined not only on ordinary real de Sitter and anti-de Sitter, but also on the rational points of the quadratic equations that define these spaces. For three-dimensional anti-de Sitter space, a simpler evolution rule is possible that descends from the Wess-Zumino-Witten equations of motion. In this case, one may replace three-dimensional anti-de Sitter space by a non-compact discrete subgroup of SL(2,R) whose structure is related to the Pell equation. A discrete version of the BTZ black hole can be constructed as a quotient of this subgroup. This discrete black hole avoids the firewall paradox by a curious mechanism: even for large black holes, there are no points inside the horizon until one reach...

  17. Reconstructing human evolution

    CERN Document Server

    Cavalli-Sforza, M

    1999-01-01

    One can reconstruct human evolution using modern genetic data and models based on the mathematical theory of evolution and its four major factors : mutation, natural selection, statistical fluctuations in finite populations (random genetic drift), and migration. Archaeology gives some help on the major dates and events of the process. Chances of studying ancient DNA are very limited but there have been a few successful results. Studying DNA instead of proteins, as was done until a few years ago, and in particular the DNA of mitochondria and of the Y chromosome which are transmitted, respectively, by the maternal line and the paternal line, has greatly simplified the analysis. It is now possible to carry the analysis on individuals, while earlier studies were of necessity based on populations. Also the evolution of ÒcultureÓ (i.e. what we learn from others), in particular that of languages, gives some help and can be greatly enlightened by genetic studies. Even though it is largely based on mechanisms of mut...

  18. Thermodynamical Arguments Against Evolution

    Science.gov (United States)

    Rosenhouse, Jason

    2017-02-01

    The argument that the second law of thermodynamics contradicts the theory of evolution has recently been revived by anti-evolutionists. In its basic form, the argument asserts that whereas evolution implies that there has been an increase in biological complexity over time, the second law, a fundamental principle of physics, shows this to be impossible. Scientists have responded primarily by noting that the second law does not rule out increases in complexity in open systems, and since the Earth receives energy from the Sun, it is an open system. This reply is correct as far as it goes, and it adequately rebuts the most crude versions of the second law argument. However, it is insufficient against more sophisticated versions, and it leaves many relevant aspects of thermodynamics unexplained. We shall consider the history of the argument, explain the nuances various anti-evolution writers have brought to it, and offer thorough explanations for why the argument is fallacious. We shall emphasize in particular that the second law is best viewed as a mathematical statement. Since anti-evolutionists never make use of the mathematical structure of thermodynamics, invocations of the second law never contribute anything substantive to their discourse.

  19. Genome evolution of Oryza

    Directory of Open Access Journals (Sweden)

    Tieyan Liu

    2014-01-01

    Full Text Available The genus Oryza is composed of approximately 24 species. Wild species of Oryza contain a largely untapped resource of agronomically important genes. As an increasing number of genomes of wild rice species have been or will be sequenced, Oryza is becoming a model system for plant comparative, functional and evolutionary genomics studies. Comparative analyses of large genomic regions and whole-genome sequences have revealed molecular mechanisms involved in genome size variation, gene movement, genome evolution of polyploids, transition of euchromatin to heterochromatin and centromere evolution in the genus Oryza. Transposon activity and removal of transposable elements by unequal recombination or illegitimate recombination are two important factors contributing to expansion or contraction of Oryza genomes. Double-strand break repair mediated gene movement, especially non-homologous end joining, is an important source of non-colinear genes. Transition of euchromatin to heterochromatin is accompanied by transposable element amplification, segmental and tandem duplication of genic segments, and acquisition of heterochromatic genes from other genomic locations. Comparative analyses of multiple genomes dramatically improve the precision and sensitivity of evolutionary inference than single-genome analyses can provide. Further investigations on the impact of structural variation, lineage-specific genes and evolution of agriculturally important genes on phenotype diversity and adaptation in the genus Oryza should facilitate molecular breeding and genetic improvement of rice.

  20. ENVIRONMENT AND PROTOSTELLAR EVOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yichen [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile); Tan, Jonathan C., E-mail: yczhang.astro@gmail.com [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States)

    2015-04-01

    Even today in our Galaxy, stars form from gas cores in a variety of environments, which may affect the properties of the resulting star and planetary systems. Here, we study the role of pressure, parameterized via ambient clump mass surface density, on protostellar evolution and appearance, focusing on low-mass Sun-like stars and considering a range of conditions from relatively low pressure filaments in Taurus, to intermediate pressures of cluster-forming clumps like the Orion Nebula Cluster, to very high pressures that may be found in the densest infrared dark clouds or in the Galactic center. We present unified analytic and numerical models for the collapse of prestellar cores, accretion disks, protostellar evolution, and bipolar outflows, coupled with radiative transfer calculations and a simple astrochemical model to predict CO gas-phase abundances. Prestellar cores in high-pressure environments are smaller and denser and thus collapse with higher accretion rates and efficiencies, resulting in higher luminosity protostars with more powerful outflows. The protostellar envelope is heated to warmer temperatures, affecting infrared morphologies (and thus classification) and astrochemical processes like CO depletion onto dust grain ice mantles (and thus CO morphologies). These results have general implications for star and planet formation, especially via their effect on astrochemical and dust grain evolution during infall to and through protostellar accretion disks.

  1. Tracking character evolution and biogeographic history through time in Cornaceae-Does choice of methods matter?%追溯山茱萸科植物的性状进化和生物地理学历史——方法选择的影响?

    Institute of Scientific and Technical Information of China (English)

    向秋云; David T. THOMAS

    2008-01-01

    This study compares results on reconstructing the ancestral state of characters and ancestral areas of distribution in Cornaceae to gain insights into the impact of using different analytical methods. Ancestral character state reconstructions were compared among three methods (parsimony, maximum likelihood, and stochastic character mapping) using MESQUITE and a full Bayesian method in BAYESTRAITS and inferences of ancestral area distribution were compared between the parsimony-based dispersal-vicariance analysis (DIVA) and a newly developed maximum likelihood (ML) method. Results indicated that among the six inflorescence and fruit characters examined, "perfect" binary characters (no homoplasy, no polymorphism within terminals, and no missing data) are little affected by choice of method, while homoplasious characters and missing data are sensitive to methods used. Ancestral areas at deep nodes of the phylogeny are substantially different between DIVA and ML and strikingly different between analyses including and excluding fossils at three deepest nodes. These results, while raising caution in making conclusions on trait evolution and historical biogeography using conventional methods, demonstrate a limitation in our current understanding of character evolution and biogeography. The biogeographic history favored by the ML analyses including fossils suggested the origin and early radiation of Cornus likely occurred in the late Cretaceous and earliest Tertiary in Europe and intercontinental disjunctions in three lineages involved movements across the North Atlantic Land Bridge (BLB) in the early and mid Tertiary. This result is congruent with the role of NALB for post-Eocene migration and in connecting tropical floras in North America and Africa, and in eastern Asia and South America. However, alternative hypotheses with an origin in eastern Asia and early Trans-Beringia migrations of the genus cannot be ruled out.

  2. Analytic Evolution of Singular Distribution Amplitudes in QCD

    Energy Technology Data Exchange (ETDEWEB)

    Radyushkin, Anatoly V. [Old Dominion University, Norfolk, VA (United States); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Tandogan Kunkel, Asli [Old Dominion University, Norfolk, VA (United States); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2014-03-01

    We describe a method of analytic evolution of distribution amplitudes (DA) that have singularities, such as non-zero values at the end-points of the support region, jumps at some points inside the support region and cusps. We illustrate the method by applying it to the evolution of a flat (constant) DA, anti-symmetric at DA and then use it for evolution of the two-photon generalized distribution amplitude. Our approach has advantages over the standard method of expansion in Gegenbauer polynomials, which requires infinite number of terms in order to accurately reproduce functions in the vicinity of singular points, and over a straightforward iteration of an initial distribution with evolution kernel. The latter produces logarithmically divergent terms at each iteration, while in our method the logarithmic singularities are summed from the start, which immediately produces a continuous curve, with only one or two iterations needed afterwards in order to get rather precise results.

  3. On Reduced Time Evolution for Initially Correlated Pure States

    CERN Document Server

    Aniello, P; Marmo, G; Ventriglia, F; Vitale, P

    2009-01-01

    A new method to deal with reduced dynamics of open systems by means of the Schr\\"odinger equation is presented. It allows one to consider the reduced time evolution for correlated and uncorrelated initial conditions.

  4. Networks of lexical borrowing and lateral gene transfer in language and genome evolution.

    Science.gov (United States)

    List, Johann-Mattis; Nelson-Sathi, Shijulal; Geisler, Hans; Martin, William

    2014-02-01

    Like biological species, languages change over time. As noted by Darwin, there are many parallels between language evolution and biological evolution. Insights into these parallels have also undergone change in the past 150 years. Just like genes, words change over time, and language evolution can be likened to genome evolution accordingly, but what kind of evolution? There are fundamental differences between eukaryotic and prokaryotic evolution. In the former, natural variation entails the gradual accumulation of minor mutations in alleles. In the latter, lateral gene transfer is an integral mechanism of natural variation. The study of language evolution using biological methods has attracted much interest of late, most approaches focusing on language tree construction. These approaches may underestimate the important role that borrowing plays in language evolution. Network approaches that were originally designed to study lateral gene transfer may provide more realistic insights into the complexities of language evolution.

  5. Measuring multiple evolution mechanisms of complex networks

    CERN Document Server

    Zhang, Qian-Ming; Zhu, Yu-Xiao; Zhou, Tao

    2014-01-01

    Traditionally, numerous simple models such as preferential attachment have been put forward to reveal the evolution mechanisms of real networks. However, previous simulations show that real networks usually are driven by various features instead of single pure mechanism. To solve this problem, some pioneers proposed a few hybrid models of mixing multiple evolution mechanisms and tried to uncover the contributions of different mechanisms. In this paper, we introduce two methods which can tackle this problem: one is based on link prediction model, and the other is based on likelihood analysis. To examine the effectiveness, we generate plenty of artificial networks which can be controlled to follow multiple mechanisms with different weights, so that we can compare the estimated weights with the true values. The experimental results show the method based on likelihood analysis performs much better and gives very accurate estimations. At last, we apply this method to real networks to see how popularity and cluster...

  6. Turbomachinery Airfoil Design Optimization Using Differential Evolution

    Science.gov (United States)

    Madavan, Nateri K.; Biegel, Bryan (Technical Monitor)

    2002-01-01

    An aerodynamic design optimization procedure that is based on a evolutionary algorithm known at Differential Evolution is described. Differential Evolution is a simple, fast, and robust evolutionary strategy that has been proven effective in determining the global optimum for several difficult optimization problems, including highly nonlinear systems with discontinuities and multiple local optima. The method is combined with a Navier-Stokes solver that evaluates the various intermediate designs and provides inputs to the optimization procedure. An efficient constraint handling mechanism is also incorporated. Results are presented for the inverse design of a turbine airfoil from a modern jet engine and compared to earlier methods. The capability of the method to search large design spaces and obtain the optimal airfoils in an automatic fashion is demonstrated. Substantial reductions in the overall computing time requirements are achieved by using the algorithm in conjunction with neural networks.

  7. Anmeldelse af Evolution, Literature and Film

    DEFF Research Database (Denmark)

    Grodal, Torben Kragh

    2011-01-01

    Diskussion af basisproblemer i evolutionær fiktionsteori med udgangspunkt i en anmeldelse af Evolution, Literature and Film......Diskussion af basisproblemer i evolutionær fiktionsteori med udgangspunkt i en anmeldelse af Evolution, Literature and Film...

  8. Solitons and periodic solutions to a couple of fractional nonlinear evolution equations

    Indian Academy of Sciences (India)

    M Mirzazadeh; M Eslami; Anjan Biswas

    2014-03-01

    This paper studies a couple of fractional nonlinear evolution equations using first integral method. These evolution equations are foam drainage equation and Klein–Gordon equation (KGE), the latter of which is considered in (2 + 1) dimensions. For the fractional evolution, the Jumarie’s modified Riemann–Liouville derivative is considered. Exact solutions to these equations are obtained.

  9. An Optimal Selection Method for Architecture Evolution Plans of Operational System-of-systems%一种作战体系结构演化方案优选方法

    Institute of Scientific and Technical Information of China (English)

    夏璐; 邢清华; 邹志刚

    2014-01-01

    Aiming at selecting the architecture evolution optimal plan of operational system-of-systems (OSoS), firstly, we define the supernetwork architecture in order to constitute the fundament of the capability description for OSoS. Secondly, based on the theory of Vague matter-element and the risk attitude of decision makers, we set up the evaluation standard to the architecture evolution plans of OSoS from the capability viewpoint. Thirdly, we improve the Vague value similarity measure model, and use entropy theory weighting the capability attributes, which facilitates the differentiation and reasonability of closeness degree measure model between the practical plan and the standard one. Finally, the numerical example shows that the proposed methodology in this paper is practical and effective.%针对作战体系结构演化方案寻优问题,本文首先定义了作战体系结构超网络,以构建体系能力描述的结构基础;其次,结合Vague 物元理论及决策者风险态度,建立了能力视角下衡量作战体系结构演化方案优劣的标准;再次,改进了Vague值的相似度计算模型,运用熵权法计算能力属性权重,以提高作战体系结构演化方案与标准方案贴近度计算的区分度及合理性;最后,通过案例证明了本文方法的实用性与有效性。

  10. Dynamical evolution of star forming regions

    CERN Document Server

    Parker, Richard J; Goodwin, Simon P; Meyer, Michael R

    2013-01-01

    We model the dynamical evolution of star forming regions with a wide range of initial properties. We follow the evolution of the regions' substructure using the Q-parameter, we search for dynamical mass segregation using the Lambda_MSR technique, and we also quantify the evolution of local density around stars as a function of mass using the Sigma_LDR method. The amount of dynamical mass segregation measured by Lambda_MSR is generally only significant for subvirial and virialised, substructured regions - which usually evolve to form bound clusters. The Sigma_LDR method shows that massive stars attain higher local densities than the median value in all regions, even those that are supervirial and evolve to form (unbound) associations. We also introduce the Q-Sigma_LDR plot, which describes the evolution of spatial structure as a function of mass-weighted local density in a star forming region. Initially dense (>1000 stars pc^{-2}), bound regions always have Q >1, Sigma_LDR > 2 after 5Myr, whereas dense unbound...

  11. Ammonia, amines, phosphine, arsine, stibine, silane, germane and stannane in organic solvents

    CERN Document Server

    Young, C L

    1985-01-01

    This volume presents a comprehensive collection and critical evaluation of solubility data published prior to June 1983 for the compounds of the title. A variety of techniques were used in the original determinations; the merits of these have been considered in the evaluation of the data. Emerging patterns of solubility behaviour for comparable systems are indicated. The editors believe that the book will both draw attention to areas where good data are lacking and stimulate further experimental work.

  12. Evolution of 3D tectonic stress field and fault movement in North China

    Institute of Scientific and Technical Information of China (English)

    陈连旺; 陆远忠; 郭若眉; 许桂林; 张杰

    2001-01-01

    Based on data of fault movement surveying, we simulate the evolution process of three dimensional stress field in North China by three dimensional finite element method. Evolutional patterns in one-year time scale from 1986 to 1997 have been illustrated and the evolution characteristics of stress field have been analyzed. In comparison with the seismic activity among that time interval in North China, we have primarily discussed the relationship between the evolution of stress field and seismic activity.

  13. Model and solving method for adaptive evolution of command and control relationship in C4 ISR system%C4 ISR 系统指挥控制关系适应性演化模型和方法研究

    Institute of Scientific and Technical Information of China (English)

    张杰勇; 蓝羽石; 易侃; 毛少杰; 王珩

    2015-01-01

    研究了C4 ISR系统结构中指挥控制关系的适应性演化问题。构建了C4 ISR系统结构中的指挥控制关系模型,在对指挥控制关系适应性演化过程分析和描述的基础上,设计了演化过程中的指挥控制关系的结构变化代价和性能代价,并以最小化总的演化代价为目标函数构建了指挥控制关系适应性演化问题的数学模型。提出了基于 n-Best 策略层级聚类方法和遗传算法(genetic algorithm,GA)的问题模型求解思路。n-Best 策略层级聚类方法用来获取每个任务阶段可行的指挥控制关系集合,而 GA 用来搜索最优的演化路径。最后通过某一仿真算例验证了求解方法的可行性、稳定性。%The adaptive evolution of command and control (C2 )relationship in C4 ISR system structure is studied.The model of the C2 relationship is established,the process of the C2 relationship adaptive evolution is analyzed and depicted,the cost of structure change and the cost of performance are designed,and the mathemat-ic model with the value of sum of evolution cost minimization as the objective function is built for the problem of the C2 relationship adaptive evolution.Then the method based on the n-Best strategy hierarchical clustering al-gorithm and genetic algorithm (GA)to solve this model is designed.The hierarchical clustering algorithm based on n-Best strategy is used for getting the feasible C2 relationship in each task window,and the GA is used for searching the best path of evolution.Finally,the applicability and stability of this solving algorithm are illustra-ted by a case of joint operational plan.

  14. Evolution before genes

    Directory of Open Access Journals (Sweden)

    Vasas Vera

    2012-01-01

    Full Text Available Abstract Background Our current understanding of evolution is so tightly linked to template-dependent replication of DNA and RNA molecules that the old idea from Oparin of a self-reproducing 'garbage bag' ('coacervate' of chemicals that predated fully-fledged cell-like entities seems to be farfetched to most scientists today. However, this is exactly the kind of scheme we propose for how Darwinian evolution could have occurred prior to template replication. Results We cannot confirm previous claims that autocatalytic sets of organic polymer molecules could undergo evolution in any interesting sense by themselves. While we and others have previously imagined inhibition would result in selectability, we found that it produced multiple attractors in an autocatalytic set that cannot be selected for. Instead, we discovered that if general conditions are satisfied, the accumulation of adaptations in chemical reaction networks can occur. These conditions are the existence of rare reactions producing viable cores (analogous to a genotype, that sustains a molecular periphery (analogous to a phenotype. Conclusions We conclude that only when a chemical reaction network consists of many such viable cores, can it be evolvable. When many cores are enclosed in a compartment there is competition between cores within the same compartment, and when there are many compartments, there is between-compartment competition due to the phenotypic effects of cores and their periphery at the compartment level. Acquisition of cores by rare chemical events, and loss of cores at division, allows macromutation, limited heredity and selectability, thus explaining how a poor man's natural selection could have operated prior to genetic templates. This is the only demonstration to date of a mechanism by which pre-template accumulation of adaptation could occur. Reviewers This article was reviewed by William Martin and Eugene Koonin.

  15. Evolution of Sedimentary Rocks

    Science.gov (United States)

    Veizer, J.; MacKenzie, F. T.

    2003-12-01

    For almost a century, it has been recognized that the present-day thickness and areal extent of Phanerozoic sedimentary strata increase progressively with decreasing geologic age. This pattern has been interpreted either as reflecting an increase in the rate of sedimentation toward the present (Barrell, 1917; Schuchert, 1931; Ronov, 1976) or as resulting from better preservation of the younger part of the geologic record ( Gilluly, 1949; Gregor, 1968; Garrels and Mackenzie, 1971a; Veizer and Jansen, 1979, 1985).Study of the rocks themselves led to similarly opposing conclusions. The observed secular (=age) variations in relative proportions of lithological types and in chemistry of sedimentary rocks (Daly, 1909; Vinogradov et al., 1952; Nanz, 1953; Engel, 1963; Strakhov, 1964, 1969; Ronov, 1964, 1982) were mostly given an evolutionary interpretation. An opposing, uniformitarian, approach was proposed by Garrels and Mackenzie (1971a). For most isotopes, the consensus favors deviations from the present-day steady state as the likely cause of secular trends.This chapter attempts to show that recycling and evolution are not opposing, but complementary, concepts. It will concentrate on the lithological and chemical attributes of sediments, but not deal with the evolution of sedimentary mineral deposits (Veizer et al., 1989) and of life ( Sepkoski, 1989), both well amenable to the outlined conceptual treatment. The chapter relies heavily on Veizer (1988a) for the sections dealing with general recycling concepts, on Veizer (2003) for the discussion of isotopic evolution of seawater, and on Morse and Mackenzie (1990) and Mackenzie and Morse (1992) for discussion of carbonate rock recycling and environmental attributes.

  16. Evolution and human sexuality.

    Science.gov (United States)

    Gray, Peter B

    2013-12-01

    The aim of this review is to put core features of human sexuality in an evolutionary light. Toward that end, I address five topics concerning the evolution of human sexuality. First, I address theoretical foundations, including recent critiques and developments. While much traces back to Darwin and his view of sexual selection, more recent work helps refine the theoretical bases to sex differences and life history allocations to mating effort. Second, I consider central models attempting to specify the phylogenetic details regarding how hominin sexuality might have changed, with most of those models honing in on transitions from a possible chimpanzee-like ancestor to the slightly polygynous and long-term bonded sociosexual partnerships observed among most recently studied hunter-gatherers. Third, I address recent genetic and physiological data contributing to a refined understanding of human sexuality. As examples, the availability of rapidly increasing genomic information aids comparative approaches to discern signals of selection in sexuality-related phenotypes, and neuroendocrine studies of human responses to sexual stimuli provide insight into homologous and derived mechanisms. Fourth, I consider some of the most recent, large, and rigorous studies of human sexuality. These provide insights into sexual behavior across other national samples and on the Internet. Fifth, I discuss the relevance of a life course perspective to understanding the evolution of human sexuality. Most research on the evolution of human sexuality focuses on young adults. Yet humans are sexual beings from gestation to death, albeit in different ways across the life course, and in ways that can be theoretically couched within life history theory.

  17. Electrochemical Hydrogen Evolution

    DEFF Research Database (Denmark)

    Laursen, A.B.; Varela Gasque, Ana Sofia; Dionigi, F.

    2012-01-01

    The electrochemical hydrogen evolution reaction (HER) is growing in significance as society begins to rely more on renewable energy sources such as wind and solar power. Thus, research on designing new, inexpensive, and abundant HER catalysts is important. Here, we describe how a simple experiment...... catalysts based on this. Suited for upper-level high school and first-year university students, this exercise involves using a basic two-cell electrochemical setup to test multiple electrode materials as catalysts at one applied potential, and then constructing a volcano curve with the resulting currents...

  18. Multitemporal conditional schema evolution

    DEFF Research Database (Denmark)

    Jensen, Ole Guttorm; Bøhlen, Michael Hanspeter

    2004-01-01

    Schema evolution is the ability of the database to respond to changes in the real world by allowing the schema to evolve.  The multidimensional conditionally evolving schema (MD-CES) is a conceptual model for conditional schema changes, which modify the schema of those tuples that satisfy...... the change condition.  The MD-CES is lossless and preserves schemas, but has an exponential space complexity.  In this paper we restrict conditional schema changes to timestamp attributes.  Specifically, we develop 1D-CES for schema versioning over one time dimension, and 2D-CES for schema versioning over...

  19. Evolution of galaxy habitability

    OpenAIRE

    Gobat, R.; Hong, S. E.

    2016-01-01

    We combine a semi-analytic model of galaxy evolution with constraints on circumstellar habitable zones and the distribution of terrestrial planets to probe the suitability of galaxies of different mass and type to host habitable planets, and how it evolves with time. We find that the fraction of stars with terrestrial planets in their habitable zone (known as habitability) depends only weakly on galaxy mass, with a maximum around 4e10 Msun. We estimate that 0.7% of all stars in Milky Way type...

  20. Demonstrating Supernova Remnant Evolution

    Science.gov (United States)

    Leahy, Denis A.; Williams, Jacqueline

    2017-01-01

    We have created a software tool to calculate at display supernova remnant evolution which includes all stages from early ejecta dominated phase to late-time merging with the interstellar medium. The software was created using Python, and can be distributed as Python code, or as an executable file. The purpose of the software is to demonstrate the different phases and transitions that a supernova remnant undergoes, and will be used in upper level undergraduate astrophysics courses as a teaching tool. The usage of the software and its graphical user interface will be demonstrated.

  1. Is evolution finished?

    Science.gov (United States)

    Davison, John A

    2004-01-01

    Since speciation seems to be no longer in progress, one is compelled to conclude that sexual reproduction is incompetent as a macroevolutionary device. I propose that the reason some might insist that evolution is still in progress stems primarily from the influence of two authorities, the geologist Charles Lyell, with his doctrine of uniformitarianism and Gregor Mendel, the discoverer of sexually mediated transmission genetics. William Bateson, the father of modern genetics, clearly foresaw the failure of Mendelism to explain macroevolutionary change, a perspective with which I am in full agreement.

  2. Evolution in the Multiverse

    CERN Document Server

    Standish, R K

    2000-01-01

    In the {\\em Many Worlds Interpretation} of quantum mechanics, the range of possible worlds (or histories) provides variation, and the Anthropic Principle is a selective principle analogous to natural selection. When looked on in this way, the ``process'' by which the laws and constants of physics is determined not too different from the process that gave rise to our current biodiversity, i.e. Darwinian evolution. This has implications for the fields of SETI and Artificial Life, which are based on a philosophy of the inevitability of life.

  3. The Earth's early evolution.

    Science.gov (United States)

    Bowring, S A; Housh, T

    1995-09-15

    The Archean crust contains direct geochemical information of the Earth's early planetary differentiation. A major outstanding question in the Earth sciences is whether the volume of continental crust today represents nearly all that formed over Earth's history or whether its rates of creation and destruction have been approximately balanced since the Archean. Analysis of neodymium isotopic data from the oldest remnants of Archean crust suggests that crustal recycling is important and that preserved continental crust comprises fragments of crust that escaped recycling. Furthermore, the data suggest that the isotopic evolution of Earth's mantle reflects progressive eradication of primordial heterogeneities related to early differentiation.

  4. Micro-analysis by U-Pb method using LAM-ICPMS and its applications for the evolution of sedimentary basins: the example from Brasilia Belt; Micro-analise pelo metodo U-Pb usando LAM-CIPMS e suas aplicacoes para a evolucao de bacias sedimentares: o exemplo da faixa Brasilia

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel, Marcio Martins; Matteini, Massimo; Junges, Sergio Luiz; Giustina, Maria Emilia Schutesky Della; Dantas, Elton Luiz; Buhn, Bernhard, E-mail: marcio@unb.br [Universidade de Brasilia (UnB), DF (Brazil). Instituto de Geociencias; Rodrigues, Joseneusa Brilhante [Servico Geologico do Brasil (CPRM), Brasilia, DF (Brazil)

    2015-07-01

    The U-Pb geochronological method using LAM-MC-ICPMS represents an important tool to investigate the geological evolution of sedimentary basins, as well as its geochronology, through the determination of upper limits for the depositional ages of detrital sedimentary rocks. The method has been applied in the Geochronology Laboratory of the Universidade de Brasilia, and in this study, a brief review of the provenance data for the sediments of the Neoproterozoic Brasilia Belt is presented and their significance for the evolution of the orogen is discussed. The results indicate that the Paranoa and Canastra Groups represent passive margin sequences formed along the western margin of the Sao Francisco-Congo continent. The Vazante Group presents similar provenance patterns, although Sm-Nd isotopic results suggest that its upper portions had contributions from younger (Neoproterozoic) sources, possibly from the Neoproterozoic Goias Magmatic Arc. On the other hand, metasediments of the Araxa and Ibia groups contain an important proportion of material derived from Neoproterozoic sources, demonstrating that they represent syn-orogenic basins. The provenance pattern of the Bambui Group is marked by an important Neoproterozoic component, showing that it constitutes a sedimentary sequence which is younger than 600 Ma, representing a foreland basin to the Brasilia Belt. (author)

  5. Microbes Drive Evolution of Animals and Plants: the Hologenome Concept

    Directory of Open Access Journals (Sweden)

    Eugene Rosenberg

    2016-03-01

    Full Text Available The hologenome concept of evolution postulates that the holobiont (host plus symbionts with its hologenome (host genome plus microbiome is a level of selection in evolution. Multicellular organisms can no longer be considered individuals by the classical definitions of the term. Every natural animal and plant is a holobiont consisting of the host and diverse symbiotic microbes and viruses. Microbial symbionts can be transmitted from parent to offspring by a variety of methods, including via cytoplasmic inheritance, coprophagy, direct contact during and after birth, and the environment. A large number of studies have demonstrated that these symbionts contribute to the anatomy, physiology, development, innate and adaptive immunity, and behavior and finally also to genetic variation and to the origin and evolution of species. Acquisition of microbes and microbial genes is a powerful mechanism for driving the evolution of complexity. Evolution proceeds both via cooperation and competition, working in parallel.

  6. Evolution of Protoplanetary Discs with Magnetically Driven Disc Winds

    CERN Document Server

    Suzuki, Takeru K; Morbidelli, Alessandro; Crida, Aurélien; Guillot, Tristan

    2016-01-01

    Aims: We investigate the evolution of protoplanetary discs (PPDs hereafter) with magnetically driven disc winds and viscous heating. Methods: We consider an initially massive disc with ~0.1 Msun to track the evolution from the early stage of PPDs. We solve the time evolution of surface density and temperature by taking into account viscous heating and the loss of the mass and the angular momentum by the disc winds within the framework of a standard alpha model for accretion discs. Our model parameters, turbulent viscosity, disc wind mass loss, and disc wind torque, which are adopted from local magnetohydrodynamical simulations and constrained by the global energetics of the gravitational accretion, largely depends on the physical condition of PPDs, particularly on the evolution of the vertical magnetic flux in weakly ionized PPDs. Results: Although there are still uncertainties concerning the evolution of the vertical magnetic flux remaining, surface densities show a large variety, depending on the combinatio...

  7. Artificial Neural Networks, Symmetries and Differential Evolution

    CERN Document Server

    Urfalioglu, Onay

    2010-01-01

    Neuroevolution is an active and growing research field, especially in times of increasingly parallel computing architectures. Learning methods for Artificial Neural Networks (ANN) can be divided into two groups. Neuroevolution is mainly based on Monte-Carlo techniques and belongs to the group of global search methods, whereas other methods such as backpropagation belong to the group of local search methods. ANN's comprise important symmetry properties, which can influence Monte-Carlo methods. On the other hand, local search methods are generally unaffected by these symmetries. In the literature, dealing with the symmetries is generally reported as being not effective or even yielding inferior results. In this paper, we introduce the so called Minimum Global Optimum Proximity principle derived from theoretical considerations for effective symmetry breaking, applied to offline supervised learning. Using Differential Evolution (DE), which is a popular and robust evolutionary global optimization method, we experi...

  8. Stellar Structure and Evolution

    CERN Document Server

    Kippenhahn, Rudolf; Weiss, Achim

    2013-01-01

    This long-awaited second edition of the classical textbook on Stellar Structure and Evolution by Kippenhahn and Weigert is a thoroughly revised version of the original text. Taking into account modern observational constraints as well as additional physical effects such as mass loss and diffusion, Achim Weiss and Rudolf Kippenhahn have succeeded in bringing the book up to the state-of-the-art with respect to both the presentation of stellar physics and the presentation and interpretation of current sophisticated stellar models. The well-received and proven pedagogical approach of the first edition has been retained. The book provides a comprehensive treatment of the physics of the stellar interior and the underlying fundamental processes and parameters. The models developed to explain the stability, dynamics and evolution of the stars are presented and great care is taken to detail the various stages in a star’s life. Just as the first edition, which remained a standard work for more than 20 years after its...

  9. Concrete Chemical Evolution

    Energy Technology Data Exchange (ETDEWEB)

    D.H. Tang

    1998-07-31

    The objectives of this analysis are to discuss and evaluate testing results that were performed for the M&O by the Pennsylvania State University (PSU) to evaluate the potential long-term evolution of organic admixtures in cementitious materials at elevated temperatures. The testing was designed to help provide a basis for a determination by the Performance Assessment group (PA) of the long-term acceptability and longevity of cementitious materials for repository use. The main purpose of the testing was to assess the evolution of gases (especially CO{sub 2}) from hydrated cement paste at elevated temperatures and to determine the impact on alkalinity, i.e., the pH value of cement paste pore solution. This information in turn can be used as scoping information to determine if further tests of this nature are needed to support PA. As part of this discussion and evaluation of the PSU results, an assessment of alkalinity in a ''cementitious repository'' and an evaluation of organic materials are presented.

  10. Evolution of Oxygenic Photosynthesis

    Science.gov (United States)

    Fischer, Woodward W.; Hemp, James; Johnson, Jena E.

    2016-06-01

    The origin of oxygenic photosynthesis was the most important metabolic innovation in Earth history. It allowed life to generate energy and reducing power directly from sunlight and water, freeing it from the limited resources of geochemically derived reductants. This greatly increased global primary productivity and restructured ecosystems. The release of O2 as an end product of water oxidation led to the rise of oxygen, which dramatically altered the redox state of Earth's atmosphere and oceans and permanently changed all major biogeochemical cycles. Furthermore, the biological availability of O2 allowed for the evolution of aerobic respiration and novel biosynthetic pathways, facilitating much of the richness we associate with modern biology, including complex multicellularity. Here we critically review and synthesize information from the geological and biological records for the origin and evolution of oxygenic photosynthesis. Data from both of these archives illustrate that this metabolism first appeared in early Paleoproterozoic time and, despite its biogeochemical prominence, is a relatively late invention in the context of our planet's history.

  11. The soliton stars evolution

    CERN Document Server

    Bednarek, I; Bednarek, Ilona; Manka, Ryszard

    1996-01-01

    The evolution of a soliton star filled with fermions is studied in the framework of general relativity. Such a system can be described by the surface tension $\\sigma$, the bag constant $B$, and the fermion number density affects the spacetime inside the soliton. Whether it is described by Friedman or de Sitter metric depends on the prevailing parameter. The whole spacetime is devided by the surface of the soliton into the false vacuum region inside the soliton and the true vacuum region outside, the latter being described by the Schwarzschild line element. The aim of this paper is to study the equations of motion of the domain wall in two cases. In the first case the de Sitter metric describes the interior in the first case, and in the second case it is replaced by the Friedman metric. In both of them the Schwarzschild metric is outside the soliton. From the analysis of obtained equations one can draw conclusions concerning further evolution of a soliton star.

  12. Ultrastructure, macromolecules, and evolution

    CERN Document Server

    Dillon, Lawrence S

    1981-01-01

    Thus far in the history of biology, two, and only two, fundamental principles have come to light that pervade and unify the entire science-the cell theory and the concept of evolution. While it is true that recently opened fields of inves­ tigation have given rise to several generalizations of wide impact, such as the universality of DNA and the energetic dynamics of ecology, closer inspection reveals them to be part and parcel of either of the first two mentioned. Because in the final analysis energy can act upon an organism solely at the cellular level, its effects may be perceived basically to represent one facet of cell me­ tabolism. Similarly, because the DNA theory centers upon the means by which cells build proteins and reproduce themselves, it too proves to be only one more, even though an exciting, aspect of the cell theory. In fact, if the matter is given closer scrutiny, evolution itself can be viewed as being a fundamental portion of the cell concept, for its effects arise only as a consequence ...

  13. Evolution Of Cosmic Strings

    CERN Document Server

    Vanchurin, V

    2005-01-01

    We investigate the evolution of finite loops and infinite strings as a part of a complete cosmic string network. We give dynamical arguments showing that the structures on infinite strings should obey a scaling law. We perform a simulation of the network which uses functional forms for the string position and thus is exact to the limits of computer arithmetic. The effective box size of our simulation is at least two orders of magnitude larger than what was previously reached. Our results confirm that the wiggles on the strings obey a scaling law described by universal power spectrum. The average distance between long strings also scales accurately with the time. Production functions of string loops do not show scaling. With low intercommutation probability p the true scaling régime is not reached until very late cosmic times, which makes it difficult to simulate such evolutions. Via the expansion of the box technique, we were able to reach scaling with a wide range of p. The physical correlation ...

  14. Evolution of dietary antioxidants.

    Science.gov (United States)

    Benzie, Iris F F

    2003-09-01

    Oxygen is vital for most organisms but, paradoxically, damages key biological sites. Oxygenic threat is met by antioxidants that evolved in parallel with our oxygenic atmosphere. Plants employ antioxidants to defend their structures against reactive oxygen species (ROS; oxidants) produced during photosynthesis. The human body is exposed to these same oxidants, and we have also evolved an effective antioxidant system. However, this is not infallible. ROS breach defences, oxidative damage ensues, accumulates with age, and causes a variety of pathological changes. Plant-based, antioxidant-rich foods traditionally formed the major part of the human diet, and plant-based dietary antioxidants are hypothesized to have an important role in maintaining human health. This hypothesis is logical in evolutionary terms, especially when we consider the relatively hypoxic environment in which humans may have evolved. In this paper, the human diet is discussed briefly in terms of its evolutionary development, different strategies of antioxidant defence are outlined, and evolution of dietary antioxidants is discussed from the perspectives of plant need and our current dietary requirements. Finally, possibilities in regard to dietary antioxidants, evolution, and human health are presented, and an evolutionary cost-benefit analysis is presented in relation to why we lost the ability to make ascorbic acid (vitamin C) although we retained an absolute requirement for it.

  15. The evolution of fungicide resistance.

    Science.gov (United States)

    Lucas, John A; Hawkins, Nichola J; Fraaije, Bart A

    2015-01-01

    Fungicides are widely used in developed agricultural systems to control disease and safeguard crop yield and quality. Over time, however, resistance to many of the most effective fungicides has emerged and spread in pathogen populations, compromising disease control. This review describes the development of resistance using case histories based on four important diseases of temperate cereal crops: eyespot (Oculimacula yallundae and Oculimacula acuformis), Septoria tritici blotch (Zymoseptoria tritici), powdery mildew (Blumeria graminis), and Fusarium ear blight (a complex of Fusarium and Microdochium spp). The sequential emergence of variant genotypes of these pathogens with reduced sensitivity to the most active single-site fungicides, methyl benzimidazole carbamates, demethylation inhibitors, quinone outside inhibitors, and succinate dehydrogenase inhibitors illustrates an ongoing evolutionary process in response to the introduction and use of different chemical classes. Analysis of the molecular mechanisms and genetic basis of resistance has provided more rapid and precise methods for detecting and monitoring the incidence of resistance in field populations, but when or where resistance will occur remains difficult to predict. The extent to which the predictability of resistance evolution can be improved by laboratory mutagenesis studies and fitness measurements, comparison between pathogens, and reconstruction of evolutionary pathways is discussed. Risk models based on fungal life cycles, fungicide properties, and exposure to the fungicide are now being refined to take account of additional traits associated with the rate of pathogen evolution. Experimental data on the selection of specific mutations or resistant genotypes in pathogen populations in response to fungicide treatments can be used in models evaluating the most effective strategies for reducing or preventing resistance. Resistance management based on robust scientific evidence is vital to prolong

  16. Toward Documentation of Program Evolution

    DEFF Research Database (Denmark)

    Vestdam, Thomas; Nørmark, Kurt

    2005-01-01

    The documentation of a program often falls behind the evolution of the program source files. When this happens it may be attractive to shift the documentation mode from updating the documentation to documenting the evolution of the program. This paper describes tools that support the documentation...... of program evolution. The tools are refinements of the Elucidative Programming tools, which in turn are inspired from Literate Programming tools. The version-aware Elucidative Programming tools are able to process a set of program source files in different versions together with unversioned documentation...... files. The paper introduces a set of fine grained program evolution steps, which are supported directly by the documentation tools. The automatic discovery of the fine grained program evolution steps makes up a platform for documenting coarse grained and more high-level program evolution steps...

  17. Plant domestication slows pest evolution.

    Science.gov (United States)

    Turcotte, Martin M; Lochab, Amaneet K; Turley, Nash E; Johnson, Marc T J

    2015-09-01

    Agricultural practices such as breeding resistant varieties and pesticide use can cause rapid evolution of pest species, but it remains unknown how plant domestication itself impacts pest contemporary evolution. Using experimental evolution on a comparative phylogenetic scale, we compared the evolutionary dynamics of a globally important economic pest - the green peach aphid (Myzus persicae) - growing on 34 plant taxa, represented by 17 crop species and their wild relatives. Domestication slowed aphid evolution by 13.5%, maintained 10.4% greater aphid genotypic diversity and 5.6% higher genotypic richness. The direction of evolution (i.e. which genotypes increased in frequency) differed among independent domestication events but was correlated with specific plant traits. Individual-based simulation models suggested that domestication affects aphid evolution directly by reducing the strength of selection and indirectly by increasing aphid density and thus weakening genetic drift. Our results suggest that phenotypic changes during domestication can alter pest evolutionary dynamics.

  18. Student Visual Communication of Evolution

    Science.gov (United States)

    Oliveira, Alandeom W.; Cook, Kristin

    2016-05-01

    Despite growing recognition of the importance of visual representations to science education, previous research has given attention mostly to verbal modalities of evolution instruction. Visual aspects of classroom learning of evolution are yet to be systematically examined by science educators. The present study attends to this issue by exploring the types of evolutionary imagery deployed by secondary students. Our visual design analysis revealed that students resorted to two larger categories of images when visually communicating evolution: spatial metaphors (images that provided a spatio-temporal account of human evolution as a metaphorical "walk" across time and space) and symbolic representations ("icons of evolution" such as personal portraits of Charles Darwin that simply evoked evolutionary theory rather than metaphorically conveying its conceptual contents). It is argued that students need opportunities to collaboratively critique evolutionary imagery and to extend their visual perception of evolution beyond dominant images.

  19. Battery parameterisation based on differential evolution via a boundary evolution strategy

    DEFF Research Database (Denmark)

    Yang, Guangya

    2013-01-01

    the advances of evolutionary algorithms (EAs). Differential evolution (DE) is selected and modified to parameterise an equivalent circuit model of lithium-ion batteries. A boundary evolution strategy (BES) is developed and incorporated into the DE to update the parameter boundaries during the parameterisation....... The method can parameterise the model without extensive data preparation. In addition, the approach can also estimate the initial SOC and the available capacity. The efficiency of the approach is verified through two battery packs, one is an 8-cell battery module and one from an electrical vehicle....

  20. Jet Quenching with Parton evolution

    CERN Document Server

    Cheng, Luan

    2009-01-01

    We report the evolution effects on jet energy loss with detailed balance. The initial conditions and parton evolution based on perturbative QCD in the chemical non-equilibrated medium and Bjorken expanding medium at RHIC are determined. The parton evolution affect the jet energy loss evidently. This will increase the energy and propagating distance dependence of the parton energy loss and will affect the shape of suppression of moderately high P_{T} hadron spectra.

  1. Nonlinear evolution equations in QCD

    OpenAIRE

    Stasto, A. M.

    2004-01-01

    The following lectures are an introduction to the phenomena of partonic saturation and nonlinear evolution equations in Quantum Chromodynamics. After a short introduction to the linear evolution, the problems of unitarity bound and parton saturation are discussed. The nonlinear Balitsky-Kovchegov evolution equation in the high energy limit is introduced, and the progress towards the understanding of the properties of its solution is reviewed. We discuss the concepts of the saturation scale, g...

  2. Optimal Control of Evolution Mixed Variational Inclusions

    Energy Technology Data Exchange (ETDEWEB)

    Alduncin, Gonzalo, E-mail: alduncin@geofisica.unam.mx [Universidad Nacional Autónoma de México, Departamento de Recursos Naturales, Instituto de Geofísica (Mexico)

    2013-12-15

    Optimal control problems of primal and dual evolution mixed variational inclusions, in reflexive Banach spaces, are studied. The solvability analysis of the mixed state systems is established via duality principles. The optimality analysis is performed in terms of perturbation conjugate duality methods, and proximation penalty-duality algorithms to mixed optimality conditions are further presented. Applications to nonlinear diffusion constrained problems as well as quasistatic elastoviscoplastic bilateral contact problems exemplify the theory.

  3. History of the evolution of cardiopulmonary resuscitation

    OpenAIRE

    2013-01-01

    Cardiopulmonary resuscitation (CPR) is as old as humankind. The evolution of CPR represents a combination of human errors and discoveries. Aim: The present study reviews the most important moments in the history of resuscitation, from the first attempts of CPR until now. Methods: The methodology followed included bibliography research from review literature, through databases PubMed, Medline, Scopus, with the use of keywords, such as cardiopulmonary arrest, cardiopulmonary resuscitation, hist...

  4. Evolution of molecular phenotypes under stabilizing selection

    Science.gov (United States)

    Nourmohammad, Armita; Schiffels, Stephan; Lässig, Michael

    2013-01-01

    Molecular phenotypes are important links between genomic information and organismic functions, fitness, and evolution. Complex phenotypes, which are also called quantitative traits, often depend on multiple genomic loci. Their evolution builds on genome evolution in a complicated way, which involves selection, genetic drift, mutations and recombination. Here we develop a coarse-grained evolutionary statistics for phenotypes, which decouples from details of the underlying genotypes. We derive approximate evolution equations for the distribution of phenotype values within and across populations. This dynamics covers evolutionary processes at high and low recombination rates, that is, it applies to sexual and asexual populations. In a fitness landscape with a single optimal phenotype value, the phenotypic diversity within populations and the divergence between populations reach evolutionary equilibria, which describe stabilizing selection. We compute the equilibrium distributions of both quantities analytically and we show that the ratio of mean divergence and diversity depends on the strength of selection in a universal way: it is largely independent of the phenotype’s genomic encoding and of the recombination rate. This establishes a new method for the inference of selection on molecular phenotypes beyond the genome level. We discuss the implications of our findings for the predictability of evolutionary processes.

  5. Evolution algebras and their applications

    CERN Document Server

    Tian, Jianjun Paul

    2008-01-01

    Behind genetics and Markov chains, there is an intrinsic algebraic structure. It is defined as a type of new algebra: as evolution algebra. This concept lies between algebras and dynamical systems. Algebraically, evolution algebras are non-associative Banach algebras; dynamically, they represent discrete dynamical systems. Evolution algebras have many connections with other mathematical fields including graph theory, group theory, stochastic processes, dynamical systems, knot theory, 3-manifolds, and the study of the Ihara-Selberg zeta function. In this volume the foundation of evolution algebra theory and applications in non-Mendelian genetics and Markov chains is developed, with pointers to some further research topics.

  6. The evolution of pathogenic trypanosomes

    Directory of Open Access Journals (Sweden)

    Jamie R. Stevens

    Full Text Available In the absence of a fossil record, the evolution of protozoa has until recently largely remained a matter for speculation. However, advances in molecular methods and phylogenetic analysis are now allowing interpretation of the "history written in the genes". This review focuses on recent progress in reconstruction of trypanosome phylogeny based on molecular data from ribosomal RNA, the miniexon and protein-coding genes. Sufficient data have now been gathered to demonstrate unequivocally that trypanosomes are monophyletic; the phylogenetic trees derived can serve as a framework to reinterpret the biology, taxonomy and present day distribution of trypanosome species, providing insights into the coevolution of trypanosomes with their vertebrate hosts and vectors. Different methods of dating the divergence of trypanosome lineages give rise to radically different evolutionary scenarios and these are reviewed. In particular, the use of one such biogeographically based approach provides new insights into the coevolution of the pathogens, Trypanosoma brucei and Trypanosoma cruzi, with their human hosts and the history of the diseases with which they are associated.

  7. On the Historical Evolution of the Methods of Administration of the Masjid in China%论我国清真寺管理模式的历史变迁

    Institute of Scientific and Technical Information of China (English)

    丁明俊

    2012-01-01

    As the center of religious activities for Chinese Muslims such as the Hui, the Masjid symbolizes the perpetuation and dissemination of Islam in China. It is also the primary means Islamic cultural preservation. The ad- ministration of the Masjid varied in according to the influence of rulers from each dynasty regarding the internal ad- ministrative system of Islam in China. From the "Fanfang" system during Tang dynasty, the "Hadi Si" during Yuan dynasty and the "Jiaofang" system, the administration of the Masjid has undergone progressive development. This includes the Three Religious Leadership system, the Religious Leadership Succession system, the Imam appointment system, and the Board system to Committee system. These systems reflect the historical evolution of Islam in adap- ting to social development in China.%清真寺是我国回族等穆斯林举行宗教活动的中心场所,也是伊斯兰教在我国传播与分布的象征,同时还承载着伊斯兰文化传承与文物保护的主要功能。随着历代统治者对伊斯兰教内部组织制度的干预,清真寺的管理制度也在不断进行更新和调整。从唐代"蕃坊"制到元代"哈的司"再向"教坊制"的转变过程中,清真寺管理也经历了三掌教制——掌教世袭制—阿洪聘任制—董事会制—民主管理制的发展过程,反映了伊斯兰教与我国社会发展相适应的历史轨迹。

  8. Evolution of Mycobacterium tuberculosis.

    Science.gov (United States)

    Behr, Marcel A

    2013-01-01

    Genomic studies have provided a refined understanding of the genetic diversity within the Mycobacterium genus, and more specifically within Mycobacterium tuberculosis. These results have informed a new perspective on the macro- and micro-evolution of the tubercle bacillus. In the first step, a M. kansasii-like opportunistic pathogen acquired new genes, through horizontal gene transfer, that enabled it to better exploit an intracellular niche and ultimately evolve into a professional pathogen. In the second step, different subspecies and strains of the M. tuberculosis complex emerged through mutation and deletion of unnecessary DNA. Understanding the differences between M. tuberculosis and related less pathogenic mycobacteria is expected to reveal key bacterial virulence mechanisms and provide opportunities to understand host resistance to mycobacterial infection. Understanding differences within the M. tuberculosis complex and the evolutionary forces shaping these differences is important for investigating the basis of its success as both a symbiont and a pathogen.

  9. Explaining Poverty Evolution

    DEFF Research Database (Denmark)

    Arndt, Channing; Hussain, Mohammad Azhar; Jones, Edward Samuel

    Measuring poverty remains a complex and contentious issue. This is particularly true in sub-Saharan Africa where poverty rates are higher, information bases typically weaker, and the underlying determinants of welfare relatively volatile. This paper employs recently collected data on household...... consumption in Mozambique to examine the evolution of consumption poverty with focus on the period 2002/03 to 2008/09. The paper contributes in four areas. First, the period in question was characterized by major movements in international commodity prices. Mozambique provides an illuminating case study...... of the implications of these world commodity price changes for living standards of poor people. Second, a novel ‘backcasting’ approach using a computable general equilibrium model of Mozambique, linked to a poverty module is introduced. Third, the backcasting approach is also employed to rigorously examine...

  10. Manufacturing network evolution

    DEFF Research Database (Denmark)

    Yang, Cheng; Farooq, Sami; Johansen, John

    2011-01-01

    Purpose – This paper examines the effect of changes at the manufacturing plant level on other plants in the manufacturing network and also investigates the role of manufacturing plants on the evolution of a manufacturing network. Design/methodology/approach –The research questions are developed...... by identifying the gaps in the reviewed literature. The paper is based on three case studies undertaken in Danish manufacturing companies to explore in detail their manufacturing plants and networks. The cases provide a sound basis for developing the research questions and explaining the interaction between...... different manufacturing plants in the network and their impact on network transformation. Findings – The paper highlights the dominant role of manufacturing plants in the continuously changing shape of a manufacturing network. The paper demonstrates that a product or process change at one manufacturing...

  11. Raptors and primate evolution.

    Science.gov (United States)

    McGraw, W Scott; Berger, Lee R

    2013-01-01

    Most scholars agree that avoiding predators is a central concern of lemurs, monkeys, and apes. However, given uncertainties about the frequency with which primates actually become prey, the selective importance of predation in primate evolution continues to be debated. Some argue that primates are often killed by predators, while others maintain that such events are relatively rare. Some authors have contended that predation's influence on primate sociality has been trivial; others counter that predation need not occur often to be a powerful selective force. Given the challenges of documenting events that can be ephemeral and irregular, we are unlikely ever to amass the volume of systematic, comparative data we have on such topics as feeding, social dynamics, or locomotor behavior. Nevertheless, a steady accumulation of field observations, insight gained from natural experiments, and novel taphonomic analyses have enhanced understanding of how primates interact with several predators, especially raptors, the subject of this review.

  12. Evolution of Business Models

    DEFF Research Database (Denmark)

    Antero, Michelle C.; Hedman, Jonas; Henningsson, Stefan

    2013-01-01

    The ERP industry has undergone dramatic changes over the past decades due to changing market demands, thereby creating new challenges and opportunities, which have to be managed by ERP vendors. This paper inquires into the necessary evolution of business models in a technology-intensive industry (e.......g., develop new offerings, engage in partnerships, and the utilize new sales channels). This paper draws from strategy process perspective to develop an evolutionary business model (EBM) framework that explains the components and processes involved. The framework is then applied to a longitudinal case study...... of SAP to explain how its success in a technology-intensive industry hinges on its ability to reconfigure its business model. The paper contributes to the extant literature on business models in two ways: first, by identifying and explaining the need for an evolutionary perspective; and second...

  13. Field Independent Cosmic Evolution

    Directory of Open Access Journals (Sweden)

    Nayem Sk

    2013-01-01

    Full Text Available It has been shown earlier that Noether symmetry does not admit a form of corresponding to an action in which is coupled to scalar-tensor theory of gravity or even for pure theory of gravity taking anisotropic model into account. Here, we prove that theory of gravity does not admit Noether symmetry even if it is coupled to tachyonic field and considering a gauge in addition. To handle such a theory, a general conserved current has been constructed under a condition which decouples higher-order curvature part from the field part. This condition, in principle, solves for the scale-factor independently. Thus, cosmological evolution remains independent of the form of the chosen field, whether it is a scalar or a tachyon.

  14. Monitoring Evolution at CERN

    CERN Document Server

    Andrade, P; Murphy, S; Pigueiras, L; Santos, M

    2015-01-01

    Over the past two years, the operation of the CERN Data Centres went through significant changes with the introduction of new mechanisms for hardware procurement, new services for cloud provisioning and configuration management, among other improvements. These changes resulted in an increase of resources being operated in a more dynamic environment. Today, the CERN Data Centres provide over 11000 multi-core processor servers, 130 PB disk servers, 100 PB tape robots, and 150 high performance tape drives. To cope with these developments, an evolution of the data centre monitoring tools was also required. This modernisation was based on a number of guiding rules: sustain the increase of resources, adapt to the new dynamic nature of the data centres, make monitoring data easier to share, give more flexibility to Service Managers on how they publish and consume monitoring metrics and logs, establish a common repository of monitoring data, optimise the handling of monitoring notifications, and replace the previous ...

  15. Viral quasispecies evolution.

    Science.gov (United States)

    Domingo, Esteban; Sheldon, Julie; Perales, Celia

    2012-06-01

    Evolution of RNA viruses occurs through disequilibria of collections of closely related mutant spectra or mutant clouds termed viral quasispecies. Here we review the origin of the quasispecies concept and some biological implications of quasispecies dynamics. Two main aspects are addressed: (i) mutant clouds as reservoirs of phenotypic variants for virus adaptability and (ii) the internal interactions that are established within mutant spectra that render a virus ensemble the unit of selection. The understanding of viruses as quasispecies has led to new antiviral designs, such as lethal mutagenesis, whose aim is to drive viruses toward low fitness values with limited chances of fitness recovery. The impact of quasispecies for three salient human pathogens, human immunodeficiency virus and the hepatitis B and C viruses, is reviewed, with emphasis on antiviral treatment strategies. Finally, extensions of quasispecies to nonviral systems are briefly mentioned to emphasize the broad applicability of quasispecies theory.

  16. Evolution of Flat Roofs

    Directory of Open Access Journals (Sweden)

    Şt. Vasiliu

    2009-01-01

    Full Text Available Roofs are constructive subassembles that are located at the top of buildings, which toghether with perimetral walls and some elements of the infrastructure belongs to the subsystem elements that close the building. Roofs must meet resistance requirements to mechanical action, thermal insulating, waterproofing and acoustic, fire resistance, durability, economy and aesthetics. The man saw the need to build roofs from the oldest ancient times. Even if the design of buildings has an empirical character, are known and are preserved until today constructions that are made in antiquity, by the Egyptians, Greeks and Romans with architectural achievements, worthy of admiration and in present time. General composition of civil construction has been influenced throughout the evolution of construction history by the level of production forces and properties of building materials available in every historical epoch. For over five millennia, building materials were stone, wood and ceramic products (concrete was used by theRomans only as filling material.

  17. The evolution of 'bricolage'.

    Science.gov (United States)

    Duboule, D; Wilkins, A S

    1998-02-01

    The past ten years of developmental genetics have revealed that most of our genes are shared by other species throughout the animal kingdom. Consequently, animal diversity might largely rely on the differential use of the same components, either at the individual level through divergent functional recruitment, or at a more integrated level, through their participation in various genetic networks. Here, we argue that this inevitably leads to an increase in the interdependency between functions that, in turn, influences the degree to which novel variations can be tolerated. In this 'transitionist' scheme, evolution is neither inherently gradualist nor punctuated but, instead, progresses from one extreme to the other, together with the increased complexity of organisms.

  18. Natural Evolution Strategies

    CERN Document Server

    Wierstra, Daan; Glasmachers, Tobias; Sun, Yi; Schmidhuber, Jürgen

    2011-01-01

    This paper presents Natural Evolution Strategies (NES), a recent family of algorithms that constitute a more principled approach to black-box optimization than established evolutionary algorithms. NES maintains a parameterized distribution on the set of solution candidates, and the natural gradient is used to update the distribution's parameters in the direction of higher expected fitness. We introduce a collection of techniques that address issues of convergence, robustness, sample complexity, computational complexity and sensitivity to hyperparameters. This paper explores a number of implementations of the NES family, ranging from general-purpose multi-variate normal distributions to heavy-tailed and separable distributions tailored towards global optimization and search in high dimensional spaces, respectively. Experimental results show best published performance on various standard benchmarks, as well as competitive performance on others.

  19. Dynamic Evolution Equations for Isolated Smoke Vortexes in Rational Mechanics

    CERN Document Server

    Jianhua, Xiao

    2011-01-01

    Smoke circle vortexes are a typical dynamic phenomenon in nature. The similar circle vortexes phenomenon appears in hurricane, turbulence, and many others. A semi-empirical method is constructed to get some intrinsic understanding about such circle vortex structures. Firstly, the geometrical motion equations for smoke circle is formulated based on empirical observations. Based on them, the mechanic dynamic motion equations are established. Finally, the general dynamic evolution equations for smoke vortex are formulated. They are dynamic evolution equations for exact stress field and dynamic evolution equations for average stress field. For industrial application and experimental data processing, their corresponding approximation equations for viscous fluid are given. Some simple discussions are made.

  20. A framework for Internet service evolution based on active object

    Institute of Scientific and Technical Information of China (English)

    HU Hua; ZHANG Yang

    2006-01-01

    The wide use of Internet Service in distributed computing and e-business has made the evolution of Internet Service to be one of the most prevalent research fields in software development domain. Traditional methods for software development cannot adapt to the challenge of Internet Service oriented software development. In this paper, we propose a new paradigm for the evolution of Internet Service with active objects from the characteristics of Internet Service and principles of active objects. The paradigm uses an automatic monitoring mechanism of active object to detect and process evolution requirement in system based on Internet Service.

  1. Multiple scales analysis and travelling wave solutions for KdV type nonlinear evolution equations

    Science.gov (United States)

    Ayhan, Burcu; Ozer, M. Naci; Bekir, Ahmet

    2017-01-01

    Nonlinear evolution equations are the mathematical models of problems that arise in many field of science. These equations has become an important field of study in applied mathematics in recent years. We apply exact solution methods and multiple scale method which is known as a perturbation method to nonlinear evolution equations. Using exact solution methods we get travelling wave solutions expressed by hyperbolic functions, trigonometric functions and rational functions. Also we derive Nonlinear Schrödinger (NLS) type equations from Korteweg-de Vries (KdV) type nonlinear evolution equations and we get approximate solutions for KdV type equations using multiple scale method. The proposed methods are direct and effective and can be used for many nonlinear evolution equations. It is shown that these methods provide a powerful mathematical tool to solve nonlinear evolution equations in mathematical physics.

  2. Surface Evolution during MBE Growth

    Science.gov (United States)

    Orme, C.; Orr, B. G.

    The evolution of surfaces grown using molecular beam epitaxy (MBE) is an interesting scientific issue as well as an important technological concern. In this review article we examine surface evolution during film growth from several different points of view. Experimental, simulational and analytical descriptions of the process are discussed.

  3. Evolution & the Cesarean Section Rate

    Science.gov (United States)

    Walsh, Joseph A.

    2008-01-01

    "Nothing in biology makes sense except in the light of evolution." This was the title of an essay by geneticist Theodosius Dobzhansky writing in 1973. Many causes have been given for the increased Cesarean section rate in developed countries, but biologic evolution has not been one of them. The C-section rate will continue to rise, because the…

  4. The cultural evolution of religion

    DEFF Research Database (Denmark)

    Bulbulia, Joseph; Geertz, Armin W.; Atkinson, Quentin D.

    2013-01-01

    I dette bidrag til en bog om kulturel evolution beskriver forfatterne religionens kulturel evolution. Kapitlet forsøger ved anvendelsen af en bred vifte af metoder og data at forklare kompleksiteten og variationen i religion inden for og på tværs of grupper gennem historien....

  5. Evolution of the TOR Pathway.

    NARCIS (Netherlands)

    Dam, T.J.P. van; Zwartkruis, F.J.; Bos, J.L.; Snel, B.

    2011-01-01

    The TOR kinase is a major regulator of growth in eukaryotes. Many components of the TOR pathway are implicated in cancer and metabolic diseases in humans. Analysis of the evolution of TOR and its pathway may provide fundamental insight into the evolution of growth regulation in eukaryotes and provid

  6. Prolegomenon to patterns in evolution.

    Science.gov (United States)

    Kauffman, Stuart A

    2014-09-01

    Despite Darwin, we remain children of Newton and dream of a grand theory that is epistemologically complete and would allow prediction of the evolution of the biosphere. The main purpose of this article is to show that this dream is false, and bears on studying patterns of evolution. To do so, I must justify the use of the word "function" in biology, when physics has only happenings. The concept of "function" lifts biology irreducibly above physics, for as we shall see, we cannot prestate the ever new biological functions that arise and constitute the very phase space of evolution. Hence, we cannot mathematize the detailed becoming of the biosphere, nor write differential equations for functional variables we do not know ahead of time, nor integrate those equations, so no laws "entail" evolution. The dream of a grand theory fails. In place of entailing laws, I propose a post-entailing law explanatory framework in which Actuals arise in evolution that constitute new boundary conditions that are enabling constraints that create new, typically unprestatable, adjacent possible opportunities for further evolution, in which new Actuals arise, in a persistent becoming. Evolution flows into a typically unprestatable succession of adjacent possibles. Given the concept of function, the concept of functional closure of an organism making a living in its world becomes central. Implications for patterns in evolution include historical reconstruction, and statistical laws such as the distribution of extinction events, or species per genus, and the use of formal cause, not efficient cause, laws.

  7. Evolutes of Hyperbolic Plane Curves

    Institute of Scientific and Technical Information of China (English)

    Shyuichi IZUMIYA; Dong He PEI; Takashi SANO; Erika TORII

    2004-01-01

    We define the notion of evolutes of curves in a hyperbolic plane and establish the relationships between singularities of these subjects and geometric invariants of curves under the action of the Lorentz group. We also describe how we can draw the picture of an evolute of a hyperbolic plane curve in the Poincar(e) disk.

  8. Identification of bilinear systems using differential evolution algorithm

    Indian Academy of Sciences (India)

    Saban Ozer; Hasan Zorlu

    2011-06-01

    In this work, a novel identification method based on differential evolution algorithm has been applied to bilinear systems and its performance has been compared to that of genetic algorithm. Box–Jenkins system and different type bilinear systems have been identified using differential evolution and genetic algorithms. The simulation results have shown that bilinear systems can be successfully and efficiently identified using these algorithms.

  9. A Review of Constraint-Handling Techniques for Evolution Strategies

    OpenAIRE

    Oliver Kramer

    2010-01-01

    Evolution strategies are successful global optimization methods. In many practical numerical problems constraints are not explicitly given. Evolution strategies have to incorporate techniques to optimize in restricted solution spaces. Famous constraint-handling techniques are penalty and multiobjective approaches. Past work has shown that in particular an ill-conditioned alignment between the coordinate system of Gaussian mutation and the constraint boundaries leads to premature convergence. ...

  10. Introduction to the Time Evolution of Open Quantum Systems

    CERN Document Server

    Rivas, Ángel

    2011-01-01

    We revise fundamental concepts in the dynamics of open quantum systems in the light of modern developments in the field. Our aim is to present a unified approach to the quantum evolution of open systems that incorporates the concepts and methods traditionally employed by different communities. We present in some detail the mathematical structure and the general properties of the dynamical maps underlying open system dynamics. We also discuss the microscopic derivation of dynamical equations, including both Markovian and non-Markovian evolutions.

  11. Evolution of Terrorist Network using Clustered approach: A Case study

    DEFF Research Database (Denmark)

    2011-01-01

    In the paper we present a cluster based approach for terrorist network evolution. We have applied hierarchical agglomerative clustering approach to 9/11 case study. We show that, how individual actors who are initially isolated from each other are converted in small clusters and result in a fully...... evolved network. This method of network evolution can help intelligence security analysts to understand the structure of the network....

  12. Synthesis and Morphological Evolution of CuGaS2 Nanostructures via a Polyol Method%醇体系中合成CuGaS2纳米晶及其形貌演变

    Institute of Scientific and Technical Information of China (English)

    刘强春; 唐凯斌

    2006-01-01

    Using ethylene glycol as solvent and reductant, CuCl2·2H2O, (NH2)2CS and self-prepared GaCl3 as the starting materials, CuGaS2 nanostrucutures were synthesized on a large scale at 220 ℃. Powder X-ray diffraction,transmission electron microscopy, field-emission scanning electron microscope, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy were used to characterize the products. It demonstrated the evolution of the CuGaS2 particles from spherical assemblies to flowerlike morphology, over time,at 220 ℃. Simultaneously, we elucidated the specific roles of reaction temperature, reaction time and solvent in the formation of the final CuGaS2 nanostructures. A possible formation mechanism of CuGaS2 nanostrucutures was also discussed. The room temperature photoluminescence spectrum showed blue-shift and an increase of intensity, with a decrease in the sizes of CuGaS2 particles.%以CuCl2·2H2O,自制的GaCl3和(NH2)2CS为原料,在乙二醇体系中合成了花状结构的CuGaS2纳米晶.产物分别用X射线粉末衍射仪、透射电子显微镜、场发射扫描电子显微镜、高分辩透射电子显微镜和X射线光电子能谱仪进行了表征.实验结果表明,220℃反应24 h得到均匀的花状纳米结构CuGaS2,它是由厚度80~100 nm的片晶组成.同时,通过反应时间的控制,可以清楚的看到由纳米颗粒到纳米球以及花状纳米结构的演变过程.另外,研究了反应温度、反应时间、溶剂等对产物和形貌的影响.此外,对花状结构纳米晶的生长机理进行了初步的探讨.室温荧光光谱表明,随粒径的降低,发光位发生了部分蓝移.

  13. ON THE EVOLUTION OF APPLIED MATHEMATICS

    Institute of Scientific and Technical Information of China (English)

    林家翘

    2003-01-01

    The recent trend in the application of mathematics to biological sciences is discussed in historical perspective. It is suggested that this new development should be regarded as a natural evolution of applied mathematics in the expansion of its scope. The mathematical concepts and methods to be used are not expected to be substantially different from those used in traditional applied mathematics. For illustration, we sketch an application of the kinetic theory of the study of dissipative systems to the study of the structure and function of protein molecules. The traditional concepts and methods of statistical physics can be successfully applied to yield predictions for comparison with empirical data.

  14. Evolution and variation of multigene families

    CERN Document Server

    Ohta, Tomoko

    1980-01-01

    During the last decade and a half, studies of evolution and variation have been revolutionized by the introduction of the methods and concepts of molecular genetics. We can now construct reliable phylogenetic trees, even when fossil records are missing, by compara­ tive studies of protein or mRNA sequences. If, in addition, paleon­ tological information is available, we can estimate the rate at which genes are substituted in the species in the course of evolution. Through the application of electrophoretic methods, it has become possible to study intraspecific variation in molecular terms. We now know that an immense genetic variability exists in a sexually repro­ ducing species, and our human species is no exception. The mathematical theory of population genetics (particularly its stochastic aspects) in conjunction with these new developments led us to formulate the "neutral theory" of molecular evolution, pointing out that chance, in the form of random gene frequency drift, is playing a much more importa...

  15. Collinearly improved JIMWLK evolution in Langevin form

    CERN Document Server

    Hatta, Yoshitaka

    2016-01-01

    The high-energy evolution of Wilson line operators, which at leading order is described by the Balitsky-JIMWLK equations, receives large radiative corrections enhanced by single and double collinear logarithms at next-to-leading order and beyond. We propose a method for resumming such logarithmic corrections to all orders, at the level of the Langevin formulation of the JIMWLK equation. The ensuing, collinearly-improved Langevin equation features generalized Wilson line operators, which depend not only upon rapidity (the logarithm of the longitudinal momentum), but also upon the transverse size of the color neutral projectile to which the Wilson lines belong. This additional scale dependence is built up during the evolution, via the condition that the successive emissions of soft gluons be ordered in time. The presence of this transverse scale in the Langevin equation furthermore allows for the resummation of the one-loop running coupling corrections.

  16. Evolution equations of von Karman type

    CERN Document Server

    Cherrier, Pascal

    2015-01-01

    In these notes we consider two kinds of nonlinear evolution problems of von Karman type on Euclidean spaces of arbitrary even dimension. Each of these problems consists of a system that results from the coupling of two highly nonlinear partial differential equations, one hyperbolic or parabolic and the other elliptic. These systems take their name from a formal analogy with the von Karman equations in the theory of elasticity in two dimensional space. We establish local (respectively global) results for strong (resp., weak) solutions of these problems and corresponding well-posedness results in the Hadamard sense. Results are found by obtaining regularity estimates on solutions which are limits of a suitable Galerkin approximation scheme. The book is intended as a pedagogical introduction to a number of meaningful application of classical methods in nonlinear Partial Differential Equations of Evolution. The material is self-contained and most proofs are given in full detail. The interested reader will gain a ...

  17. Trends in Substitution Models of Molecular Evolution

    Directory of Open Access Journals (Sweden)

    Miguel eArenas

    2015-10-01

    Full Text Available Substitution models of evolution describe the process of genetic variation through fixed mutations and constitute the basis of the evolutionary analysis at the molecular level. Almost forty years after the development of first substitution models, highly sophisticated and data-specific substitution models continue emerging with the aim of better mimicking real evolutionary processes. Here I describe current trends in substitution models of DNA, codon and amino acid sequence evolution, including advantages and pitfalls of the most popular models. The perspective concludes that despite the large number of currently available substitution models, further research is required for more realistic modeling, especially for DNA coding and amino acid data. Additionally, the development of more accurate complex models should be coupled with new implementations and improvements of methods and frameworks for substitution model selection and downstream evolutionary analysis.

  18. Statistical Mechanics and Thermodynamics of Viral Evolution

    Science.gov (United States)

    Jones, Barbara; Kaufman, James

    Using methods drawn from physics we study the life cycle of viruses. We analyze a model of viral infection and evolution using the ``grand canonical ensemble'' and formalisms from statistical mechanics and thermodynamics. Using this approach we determine possible genetic states of a model virus and host as a function of two independent pressures-immune response and system temperature. We show the system has a real thermodynamic temperature, and discover a new phase transition between a positive temperature regime of normal replication and a negative temperature ``disordered'' phase of the virus. We distinguish this from previous observations of a phase transition that arises as a function of mutation rate. From an evolutionary biology point of view, at steady state the viruses naturally evolve to distinct quasispecies. The approach used here could be refined to apply to real biological systems, perhaps providing insight into immune escape, the emergence of novel pathogens and other results of viral evolution.

  19. Dynamic Origin of Evolution and Social Transformation

    CERN Document Server

    Kirilyuk, Andrei P

    2012-01-01

    We analyse the unreduced, nonperturbative dynamics of an arbitrary many-body interaction process with the help of the generalised effective potential method and reveal the well-specified universal origin of change (emergence), time and evolution in an a priori conservative, time-independent system. It appears together with the universal dynamic complexity definition, where this unified complexity conservation and transformation constitutes the essence of evolution. We then consider the detailed structure of this universal evolutionary process showing its step-wise, "punctuated" character, now provided with the exact mathematical description. Comparing the expected features of a revolutionary complexity transition near a step-like complexity upgrade with the currently observed behaviour of world's social and economic systems, we prove the necessity of complexity revolution towards the superior civilisation level of well-defined nature, the only alternative being an equally dramatic and irreversible degradation...

  20. New traveling wave solutions for nonlinear evolution equations

    Energy Technology Data Exchange (ETDEWEB)

    El-Wakil, S.A. [Theoretical Research Group, Physics Department, Faculty of Science, Mansoura University, 35516 Mansoura (Egypt); Madkour, M.A. [Theoretical Research Group, Physics Department, Faculty of Science, Mansoura University, 35516 Mansoura (Egypt); Abdou, M.A. [Theoretical Research Group, Physics Department, Faculty of Science, Mansoura University, 35516 Mansoura (Egypt)]. E-mail: m_abdou_eg@yahoo.com

    2007-06-11

    The generalized Jacobi elliptic function expansion method is used with a computerized symbolic computation for constructing the new exact traveling wave solutions. The validity and reliability of the method is tested by its applications on a class of nonlinear evolution equations of special interest in mathematical physics. As a result, many exact traveling wave solutions are obtained which include the kink-shaped solutions, bell-shaped solutions, singular solutions and periodic solutions. The method is straightforward and concise, and it can also be applied to other nonlinear evolution equations in mathematical physics.