908 resultados para one element per member


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Background of the Work: The phylogenetic position and evolution of Hemidactylus anamallensis (family Gekkonidae) has been much debated in recent times. In the past it has been variously assigned to genus Hoplodactylus (Diplodactylidae) as well as a monotypic genus `Dravidogecko' (Gekkonidae). Since 1995, this species has been assigned to Hemidactylus, but there is much disagreement between authors regarding its phylogenetic position within this genus. In a recent molecular study H. anamallensis was sister to Hemidactylus but appeared distinct from it in both mitochondrial and nuclear markers. However, this study did not include genera closely allied to Hemidactylus, thus a robust evaluation of this hypothesis was not undertaken. Methods: The objective of this study was to investigate the phylogenetic position of H. anamallensis within the gekkonid radiation. To this end, several nuclear and mitochondrial markers were sequenced from H. anamallensis, selected members of the Hemidactylus radiation and genera closely allied to Hemidactylus. These sequences in conjunction with published sequences were subjected to multiple phylogenetic analyses. Furthermore the nuclear dataset was also subjected to molecular dating analysis to ascertain the divergence between H. anamallensis and related genera. Results and Conclusion: Results showed that H. anamallensis lineage was indeed sister to Hemidactylus group but was separated from the rest of the Hemidactylus by a long branch. The divergence estimates supported a scenario wherein H. anamallensis dispersed across a marine barrier to the drifting peninsular Indian plate in the late Cretaceous whereas Hemidactylus arrived on the peninsular India after the Indian plate collided with the Eurasian plate. Based on these molecular evidence and biogeographical scenario we suggest that the genus Dravidogecko should be resurrected.

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A new method of modeling partial delamination in composite beams is proposed and implemented using the finite element method. Homogenized cross-sectional stiffness of the delaminated beam is obtained by the proposed analytical technique, including extension-bending, extension-twist and torsion-bending coupling terms, and hence can be used with an existing finite element method. A two noded C1 type Timoshenko beam element with 4 degrees of freedom per node for dynamic analysis of beams is implemented. The results for different delamination scenarios and beams subjected to different boundary conditions are validated with available experimental results in the literature and/or with the 3D finite element simulation using COMSOL. Results of the first torsional mode frequency for the partially delaminated beam are validated with the COMSOL results. The key point of the proposed model is that partial delamination in beams can be analyzed using a beam model, rather than using 3D or plate models. (c) 2013 Elsevier B.V. All rights reserved.

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We present a detailed timing and spectral analysis of the Be X-ray binary SW J2000.6+3210 discovered by the Burst Alert Telescope Galactic plane survey. Two Suzaku observations of the source made at six months interval, reveal pulsations at similar to 890 s for both observations with a much weaker pulse fraction in the second one. Pulsations are clearly seen in the energy band of 0.3-10 keV of X-ray Imaging Spectrometer for both observations and at high energies up to 40 keV for the second observation. The broad-band X-ray spectrum is consistent with a power-law and high-energy cut-off model along with a hot blackbody component. No change in spectral parameters is detected between the observations. We have also analysed several short observations of the source with Swift/XRT and detected only a few per cent variation in flux around a mean value of 3.5 x 10(-11) erg cm(-2) s(-1). The results indicate that SW J2000.6+3210 is a member of persistent Be X-ray binaries which have the same broad characteristics as this source.

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Molecular dynamics simulations of bilayers in a surfactant/co-surfactant/water system with explicit solvent molecules show formation of topologically distinct gel phases depending upon the bilayer composition. At low temperatures, the bilayers transform from the tilted gel phase, L beta', to the one dimensional (1D) rippled, P beta' phase as the surfactant concentration is increased. More interestingly, we observe a two dimensional (2D) square phase at higher surfactant concentration which, upon heating, transforms to the gel L beta' phase. The thickness modulations in the 1D rippled and square phases are asymmetric in two surfactant leaflets and the bilayer thickness varies by a factor of similar to 2 between maximum and minimum. The 1D ripple consists of a thinner interdigitated region of smaller extent alternating with a thicker non-interdigitated region. The 2D ripple phase is made up of two superimposed square lattices of maximum and minimum thicknesses with molecules of high tilt forming a square lattice translated from the lattice formed with the thickness minima. Using Voronoi diagrams we analyze the intricate interplay between the area-per-head-group, height modulations and chain tilt for the different ripple symmetries. Our simulations indicate that composition plays an important role in controlling the formation of low temperature gel phase symmetries and rippling accommodates the increased area-per-head-group of the surfactant molecules.

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A closed-form expression for the dual of dissipation potential is derived within the framework of irreversible thermodynamics using the principles of dimensional analysis and self-similarity. Through this potential, a damage evolution law is proposed for concrete under fatigue loading using the concepts of damage mechanics in conjunction with fracture mechanics. The proposed law is used to compute damage in a volume element when a member is subjected to fatigue loading. The evolution of damage from microcracking to macrocracking of the entire member is captured through a series of volume elements failing one after the other. The number of loading cycles to failure of the member is obtained as the summation of number of cycles to failure for each individual volume element. A parametric study is conducted to determine the effect of the size of the volume element on the model's prediction of fatigue life. A global damage index is also defined, and the residual moment carrying capacity of damaged beams is evaluated. Through a deterministic sensitivity analysis, it is found that the load range and maximum aggregate size are the most influencing parameters on the fatigue life of a plain concrete beam.

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Streamwise streaks, their lift-up and streak instability are integral to the bypass transition process. An experimental study has been carried out to find the effect of a mesh placed normal to the flow and at different wall-normal locations in the late stages of two transitional flows induced by free-stream turbulence (FST) and an isolated roughness element. The mesh causes an approximately 30% reduction in the free-stream velocity, and mild acceleration, irrespective of its wall-normal location. Interestingly, when located near the wall, the mesh suppresses several transitional events leading to transition delay over a large downstream distance. The transition delay is found to be mainly caused by suppression of the lift-up of the high-shear layer and its distortion, along with modification of the spanwise streaky structure to an orderly one. However, with the mesh well away from the wall, the lifted-up shear layer remains largely unaffected, and the downstream boundary layer velocity profile develops an overshoot which is found to follow a plane mixing layer type profile up to the free stream. Reynolds stresses, and the size and strength of vortices increase in this mixing layer region. This high-intensity disturbance can possibly enhance transition of the accelerated flow far downstream, although a reduction in streamwise turbulence intensity occurs over a short distance downstream of the mesh. However, the shape of the large-scale streamwise structure in the wall-normal plane is found to be more or less the same as that without the mesh.

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This paper considers the problem of receive antenna selection (AS) in a multiple-antenna communication system having a single radio-frequency (RF) chain. The AS decisions are based on noisy channel estimates obtained using known pilot symbols embedded in the data packets. The goal here is to minimize the average packet error rate (PER) by exploiting the known temporal correlation of the channel. As the underlying channels are only partially observed using the pilot symbols, the problem of AS for PER minimization is cast into a partially observable Markov decision process (POMDP) framework. Under mild assumptions, the optimality of a myopic policy is established for the two-state channel case. Moreover, two heuristic AS schemes are proposed based on a weighted combination of the estimated channel states on the different antennas. These schemes utilize the continuous valued received pilot symbols to make the AS decisions, and are shown to offer performance comparable to the POMDP approach, which requires one to quantize the channel and observations to a finite set of states. The performance improvement offered by the POMDP solution and the proposed heuristic solutions relative to existing AS training-based approaches is illustrated using Monte Carlo simulations.

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In this paper, the Gaussian many-to-one X channel (XC), which is a special case of general multiuser XC, is studied. In the Gaussian many-to-one XC, communication links exist between all transmitters and one of the receivers, along with a communication link between each transmitter and its corresponding receiver. As per the XC assumption, transmission of messages is allowed on all the links of the channel. This communication model is different from the corresponding manyto- one interference channel (IC). Transmission strategies, which involve using Gaussian codebooks and treating interference from a subset of transmitters as noise, are formulated for the above channel. Sum-rate is used as the criterion of optimality for evaluating the strategies. Initially, a 3 x 3 many-to-one XC is considered and three transmission strategies are analyzed. The first two strategies are shown to achieve sum-rate capacity under certain channel conditions. For the third strategy, a sum-rate outer bound is derived and the gap between the outer bound and the achieved rate is characterized. These results are later extended to the K x K case. Next, a region in which the many-to-one XC can be operated as a many-to-one IC without the loss of sum-rate is identified. Furthermore, in the above region, it is shown that using Gaussian codebooks and treating interference as noise achieve a rate point that is within K/2 -1 bits from the sum-rate capacity. Subsequently, some implications of the above results to the Gaussian many-to-one IC are discussed. Transmission strategies for the many-to-one IC are formulated, and channel conditions under which the strategies achieve sum-rate capacity are obtained. A region where the sum-rate capacity can be characterized to within K/2 -1 bits is also identified. Finally, the regions where the derived channel conditions are satisfied for each strategy are illustrated for a 3 x 3 many-to-one XC and the corresponding many-to-one IC.

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We present in this paper the application of B-P constitutive equations in finite element analysis of high velocity impact. The impact process carries out in so quick time that the heat-conducting can be neglected and meanwhile, the functions of temperature in equations need to be replaced by functions of plastic work. The material constants in the revised equations can be determined by comparison of the one-dimensional calculations with the experiments of Hopkinson bar. It can be seen from the comparison of the calculation with the experiment of a tungsten alloy projectile impacting a three-layer plate that the B-P constitutive equations in that the functions of temperature were replaced by the functions of plastic work can be used to analysis of high velocity impact.

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Three-dimensional discrete element face-to-face contact model with fissure water pressure is established in this paper and the model is used to simulate three-stage process of landslide under fissure water pressure in the opencast mine, according to the actual state of landslide in Panluo iron mine where landslide happened in 1990 and was fathered in 1999. The calculation results show that fissure water pressure on the sliding surface is the main reason causing landslide and the local soft interlayer weakens the stability of slope. If the discrete element method adopts the same assumption as the limit equilibrium method, the results of two methods are in good agreement; while if the assumption is not adopted in the discrete element method, the critical phi numerically calculated is less than the one calculated by use of the limit equilibrium method for the same C. Thus, from an engineering point of view, the result from the discrete element model simulation is safer and has more widely application since the discrete element model takes into account the effect of rock mass structures.

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Resumen: La cuestión del riesgo tecnológico es ciertamente controvertida, como se manifiesta en el ruidoso debate entre las organizaciones ambientalistas y las empresas promotoras de la tecnología. Uno de los elementos centrales es el valor de la ciencia para dirimir ese debate. Por un lado, su objetividad está en duda. Por otro, la cuestión del riesgo reintroduce la cuestión de la subjetividad. Aunque la ciencia lograra una cabal y objetiva comprensión de la probabilidad y la magnitud del daño que potencialmente produciría un riesgo tecnológico, las actitudes frente al mismo son de naturaleza subjetiva, y por lo tanto también la decisión correcta. Una sociedad puede tolerar un riesgo en pos del beneficio tecnológico asociado mientras otra no. La economía ambiental realiza un aporte valioso en esta cuestión. Mediante sus métodos más elaborados permite integrar el elemento subjetivo de la apreciación del riesgo en el análisis del riesgo tecnológico. De este modo es posible realizar un análisis científico de la cuestión que contemple las actitudes de los miembros de la sociedad frente el riesgo.

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El siglo XVI americano fue escenario de la lucha de partidos entre los españoles que defendieron con vigorosa fidelidad a sus respectivos líderes. En la Conquista del Perú se encuentra el caso que mejor demuestra el nivel de violencia que alcanzaron las rivalidades partidarias. Fue en la singular, difícil y posteriormente violenta relación entre Diego de Almagro y Francisco Pizarro desde la salida de Panamá en 1524 hasta la lucha por la dominación de la ciudad del Cuzco en 1538.

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It is shown that the variable power singularity of the strain field at the crack tip can be obtained by the simple technique of collapsing quadrilateral isoparametric elements into triangular elements around the crack tip and adequately shifting the side-nodes adjacent to this crack tip. The collapsed isoparametric elements have the desired singularity at crack tip along any ray. The strain expressions for a single element have been derived and in addition to the desired power singularity, additional singularities are revealed. Numerical examples have shown that triangular elements formed by collapsing one side lead to excellent results.

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The territory of the European Union is made up of a rich and wide-ranging universe of languages, which is not circumscribed to the «State languages». The existence of multilingualism is one of Europe’s defining characteristics and it should remain so in the constantly evolving model of Europe’s political structure. Nonetheless, until now, the official use of languages has been limited to the «State languages» and has been based on a concept of state monolingualism that has led to a first level of hierarchization among the languages of Europe. This has affected the very concept of European language diversity. The draft of the treaty establishing a European Constitution contains various language-related references that can be grouped in two major categories: on the one hand, those references having to do the constitutional status of languages, and on the other, those regarding the recognition of European language diversity. Both issues are dealt with in this article. In analyzing the legal regime governing languages set forth in the draft of the constitutional treaty, we note that the draft is not based on the concept of the official status of languages. The language regulation contained in the draft of the constitutional treaty is limited in character. The constitutional language regime is based on the concept of Constitutional languages but the official status of languages is not governed by this rule. The European Constitution merely enunciates rights governing language use for European citizens vis-à-vis the languages of the Constitution and refers the regulation of the official status of languages to the Council, which is empowered to set and modify that status by unanimous decision. Because of its broad scope, this constitutes a regulatory reservation. In the final phase of the negotiation process a second level of constitutional recognition of languages would be introduced, linked to those that are official languages in the member states (Catalan, Basque, Galician, etc.). These languages, however, would be excluded from the right to petition; they would constitute a tertium genus, an intermediate category between the lan guages benefiting from the language rights recognized under the Constitution and those other languages for which no status is recognized in the European institutional context. The legal functionality of this second, intermediate category will depend on the development of standards, i.e., it will depend on the entrée provided such languages in future reforms of the institutional language regime. In a later section, the article reflects on European Union language policy with regard to regional or minority languages, concluding that the Union has not acted in accordance with defined language policy guidelines when it has been confronted, in the exercise of its powers, with regional or minority languages (or domestic legislation having to do with language demands). The Court of Justice has endeavoured to resolve on a case by case basis the conflicts raised between community freedoms and the normative measures that protect languages. Thus, using case law, the Court has set certain language boundaries for community freedoms. The article concludes by reflecting on the legal scope of the recognition of European language diversity referred to in Article II-82 of the European Constitution and the possible measures to implement the precept that might constitute the definition of a true European language policy on regional or minority languages. Such a policy has yet to be defined.

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(Document pdf contains 193 pages) Executive Summary (pdf, < 0.1 Mb) 1. Introduction (pdf, 0.2 Mb) 1.1 Data sharing, international boundaries and large marine ecosystems 2. Objectives (pdf, 0.3 Mb) 3. Background (pdf, < 0.1 Mb) 3.1 North Pacific Ecosystem Metadatabase 3.2 First federation effort: NPEM and the Korea Oceanographic Data Center 3.2 Continuing effort: Adding Japan’s Marine Information Research Center 4. Metadata Standards (pdf, < 0.1 Mb) 4.1 Directory Interchange Format 4.2 Ecological Metadata Language 4.3 Dublin Core 4.3.1. Elements of DC 4.4 Federal Geographic Data Committee 4.5 The ISO 19115 Metadata Standard 4.6 Metadata stylesheets 4.7 Crosswalks 4.8 Tools for creating metadata 5. Communication Protocols (pdf, < 0.1 Mb) 5.1 Z39.50 5.1.1. What does Z39.50 do? 5.1.2. Isite 6. Clearinghouses (pdf, < 0.1 Mb) 7. Methodology (pdf, 0.2 Mb) 7.1 FGDC metadata 7.1.1. Main sections 7.1.2. Supporting sections 7.1.3. Metadata validation 7.2 Getting a copy of Isite 7.3 NSDI Clearinghouse 8. Server Configuration and Technical Issues (pdf, 0.4 Mb) 8.1 Hardware recommendations 8.2 Operating system – Red Hat Linux Fedora 8.3 Web services – Apache HTTP Server version 2.2.3 8.4 Create and validate FGDC-compliant Metadata in XML format 8.5 Obtaining, installing and configuring Isite for UNIX/Linux 8.5.1. Download the appropriate Isite software 8.5.2. Untar the file 8.5.3. Name your database 8.5.4. The zserver.ini file 8.5.5. The sapi.ini file 8.5.6. Indexing metadata 8.5.7. Start the Clearinghouse Server process 8.5.8. Testing the zserver installation 8.6 Registering with NSDI Clearinghouse 8.7 Security issues 9. Search Tutorial and Examples (pdf, 1 Mb) 9.1 Legacy NSDI Clearinghouse search interface 9.2 New GeoNetwork search interface 10. Challenges (pdf, < 0.1 Mb) 11. Emerging Standards (pdf, < 0.1 Mb) 12. Future Activity (pdf, < 0.1 Mb) 13. Acknowledgments (pdf, < 0.1 Mb) 14. References (pdf, < 0.1 Mb) 15. Acronyms (pdf, < 0.1 Mb) 16. Appendices 16.1. KODC-NPEM meeting agendas and minutes (pdf, < 0.1 Mb) 16.1.1. Seattle meeting agenda, August 22–23, 2005 16.1.2. Seattle meeting minutes, August 22–23, 2005 16.1.3. Busan meeting agenda, October 10–11, 2005 16.1.4. Busan meeting minutes, October 10–11, 2005 16.2. MIRC-NPEM meeting agendas and minutes (pdf, < 0.1 Mb) 16.2.1. Seattle Meeting agenda, August 14-15, 2006 16.2.2. Seattle meeting minutes, August 14–15, 2006 16.2.3. Tokyo meeting agenda, October 19–20, 2006 16.2.4. Tokyo, meeting minutes, October 19–20, 2006 16.3. XML stylesheet conversion crosswalks (pdf, < 0.1 Mb) 16.3.1. FGDCI to DIF stylesheet converter 16.3.2. DIF to FGDCI stylesheet converter 16.3.3. String-modified stylesheet 16.4. FGDC Metadata Standard (pdf, 0.1 Mb) 16.4.1. Overall structure 16.4.2. Section 1: Identification information 16.4.3. Section 2: Data quality information 16.4.4. Section 3: Spatial data organization information 16.4.5. Section 4: Spatial reference information 16.4.6. Section 5: Entity and attribute information 16.4.7. Section 6: Distribution information 16.4.8. Section 7: Metadata reference information 16.4.9. Sections 8, 9 and 10: Citation information, time period information, and contact information 16.5. Images of the Isite server directory structure and the files contained in each subdirectory after Isite installation (pdf, 0.2 Mb) 16.6 Listing of NPEM’s Isite configuration files (pdf, < 0.1 Mb) 16.6.1. zserver.ini 16.6.2. sapi.ini 16.7 Java program to extract records from the NPEM metadatabase and write one XML file for each record (pdf, < 0.1 Mb) 16.8 Java program to execute the metadata extraction program (pdf, < 0.1 Mb) A1 Addendum 1: Instructions for Isite for Windows (pdf, 0.6 Mb) A2 Addendum 2: Instructions for Isite for Windows ADHOST (pdf, 0.3 Mb)