973 resultados para Alkene, carbon maximum number
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In this paper, the implementation aspects and constraints of the simplest network coding (NC) schemes for a two-way relay channel (TWRC) composed of a user equipment (mobile terminal), an LTE relay station (RS) and an LTE base station (eNB) are considered in order to assess the usefulness of the NC in more realistic scenarios. The information exchange rate gain (IERG), the energy reduction gain (ERG) and the resource utilization gain (RUG) of the NC schemes with and without subcarrier division duplexing (SDD) are obtained by computer simulations. The usefulness of the NC schemes are evaluated for varying traffic load levels, the geographical distances between the nodes, the RS transmit powers, and the maximum numbers of retransmissions. Simulation results show that the NC schemes with and without SDD, have the throughput gains 0.5% and 25%, the ERGs 7 - 12% and 16 - 25%, and the RUGs 0.5 - 3.2%, respectively. It is found that the NC can provide performance gains also for the users at the cell edge. Furthermore, the ERGs of the NC increase with the transmit power of the relay while the ERGs of the NC remain the same even when the maximum number of retransmissions is reduced.
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We report the impact of cascaded reconfigurable optical add-drop multiplexer induced penalties on coherently-detected 28 Gbaud polarization multiplexed m-ary quadrature amplitude modulation (PM m-ary QAM) WDM channels. We investigate the interplay between different higher-order modulation channels and the effect of filter shapes and bandwidth of (de)multiplexers on the transmission performance, in a segment of pan-European optical network with a maximum optical path of 4,560 km (80km x 57 spans). We verify that if the link capacities are assigned assuming that digital back propagation is available, 25% of the network connections fail using electronic dispersion compensation alone. However, majority of such links can indeed be restored by employing single-channel digital back-propagation employing less than 15 steps for the whole link, facilitating practical application of DBP. We report that higher-order channels are most sensitive to nonlinear fiber impairments and filtering effects, however these formats are less prone to ROADM induced penalties due to the reduced maximum number of hops. Furthermore, it has been demonstrated that a minimum filter Gaussian order of 3 and bandwidth of 35 GHz enable negligible excess penalty for any modulation order.
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To guarantee QoS for multicast transmission, admission control for multicast sessions is expected. Probe-based multicast admission control (PBMAC) scheme is a scalable and simple approach. However, PBMAC suffers from the subsequent request problem which can significantly reduce the maximum number of multicast sessions that a network can admit. In this letter, we describe the subsequent request problem and propose an enhanced PBMAC scheme to solve this problem. The enhanced scheme makes use of complementary probing and remarking which require only minor modification to the original scheme. By using a fluid-based analytical model, we are able to prove that the enhanced scheme can always admit a higher number of multicast sessions. Furthermore, we present validation of the analytical model using packet based simulation. Copyright © 2005 The Institute of Electronics, Information and Communication Engineers.
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This research develops a methodology and model formulation which suggests locations for rapid chargers to help assist infrastructure development and enable greater battery electric vehicle (BEV) usage. The model considers the likely travel patterns of BEVs and their subsequent charging demands across a large road network, where no prior candidate site information is required. Using a GIS-based methodology, polygons are constructed which represent the charging demand zones for particular routes across a real-world road network. The use of polygons allows the maximum number of charging combinations to be considered whilst limiting the input intensity needed for the model. Further polygons are added to represent deviation possibilities, meaning that placement of charge points away from the shortest path is possible, given a penalty function. A validation of the model is carried out by assessing the expected demand at current rapid charging locations and comparing to recorded empirical usage data. Results suggest that the developed model provides a good approximation to real world observations, and that for the provision of charging, location matters. The model is also implemented where no prior candidate site information is required. As such, locations are chosen based on the weighted overlay between several different routes where BEV journeys may be expected. In doing so many locations, or types of locations, could be compared against one another and then analysed in relation to siting practicalities, such as cost, land permission and infrastructure availability. Results show that efficient facility location, given numerous siting possibilities across a large road network can be achieved. Slight improvements to the standard greedy adding technique are made by adding combination weightings which aim to reward important long distance routes that require more than one charge to complete.
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We collect data about 172 countries: their parliaments, level of corruption, perceptions of corruption of parliament and political parties. We find weak empirical evidence supporting the conclusion that corruption increases as the number of parties increases. To provide a theoretical explanation of this finding we present a simple theoretical model of parliaments formed by parties, which must decide whether to accept or reject a proposal in the presence of a briber, who is interested in having the bill passed. We compute the number of deputies the briber needs to persuade on average in parliaments with different structures described by the number of parties, the voting quota, and the allocation of seats among parties. We find that the average number of seats needed to be bribed decreases as the number of parties increases. Restricting the minimal number of seats a party may have, we show that the average number of seats to be bribed is smaller in parliaments without small parties. Restricting the maximum number of seats a party may have, we find that under simple majority the average number of seats needed to be bribed is smaller for parliaments in which one party has majority, but under qualified majority it hardly changes.
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This paper deals with finding the maximum number of security policies without conflicts. By doing so we can remove security loophole that causes security violation. We present the problem of maximum compatible security policy and its relationship to the problem of maximum acyclic subgraph, which is proved to be NP-hard. Then we present a polynomial-time approximation algorithm and show that our result has approximation ratio for any integer with complexity .
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This study examines the triple bottom line of sustainability, in the context of both profit-oriented and non-profit oriented organizations. Sustainability is a compound result of interaction between economic, environmental, and social dimensions. Sustainability cannot be achieved without balance between all three dimensions, which has implications for measuring sustainability and prioritizing goals. This study demonstrates a method for measuring organizational sustainability achievement in these three dimensions of sustainability. Content analysis of the annual reports of corporations from the United States, Continental Europe (and Scandinavia), and Asia reveals that the economic dimension remains the preeminent aspect, and corporations still have a long way to go to reach comprehensive sustainability by maintaining a balance between the three dimensions of sustainability. The analysis also shows a high level of isomorphism in the sustainability practices of corporations, suggesting that even the most sustainable corporations are taking a somewhat passive role in prioritizing sustainability goals. A list of 25 terms for each dimension of sustainability (economic, environmental, and social) has been developed which can be used by corporations to develop and communicate their sustainability practices most effectively to the maximum number of their stakeholders. In contrast, botanical gardens demonstrate more balance among the three dimensions of sustainability.
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He was obtained and studied the feasibility of using TPA (Tissue Cotton Plan) screen type, for bagging, with a weight of 207.9 g / m2 in a composite of orthophthalic crystal polyester resin matrix. The process for obtaining the composite was tested against the maximum number of layers that could be used without compromising the processability and manufacturing of CPs in compression mold. Five configurations / formulations were selected and tested at 1, 4, 8, 10 and 12 layers of cotton tissue - TPA. TPA was not subjected to chemical treatment, only by passing a mechanical washing process. The composite in its various configurations / formulations was characterized to determine its physical properties. The properties of the composite were higher viability resistance to bending, approaching the matrix and impact resistance, superiority in relation to the polyester resin. Another property that has shown good result compared to other composite has water absorption. Analyzing all the properties set the settings / formulations with higher viability were TA8 and TA10, by combining good processability and higher mechanical strength, with lower loss compared to polyester resin matrix. The composite showed lower mechanical behavior of the resin matrix for all the formulations studied except the impact resistance. The SEM showed a good adhesion between the layers of TPA and polyester resin matrix, without the presence of micro voids in the matrix confirming the efficient manufacturing process of the samples for characterization. The composite proposed proved to be viable for the fabrication of structures with low requests from mechanical stresses, and as demonstrated for the manufacture of solar and wind prototypes, and packaging, shelving, decorative items, crafts and shelves, with good visual appearance.
Resumo:
He was obtained and studied the feasibility of using TPA (Tissue Cotton Plan) screen type, for bagging, with a weight of 207.9 g / m2 in a composite of orthophthalic crystal polyester resin matrix. The process for obtaining the composite was tested against the maximum number of layers that could be used without compromising the processability and manufacturing of CPs in compression mold. Five configurations / formulations were selected and tested at 1, 4, 8, 10 and 12 layers of cotton tissue - TPA. TPA was not subjected to chemical treatment, only by passing a mechanical washing process. The composite in its various configurations / formulations was characterized to determine its physical properties. The properties of the composite were higher viability resistance to bending, approaching the matrix and impact resistance, superiority in relation to the polyester resin. Another property that has shown good result compared to other composite has water absorption. Analyzing all the properties set the settings / formulations with higher viability were TA8 and TA10, by combining good processability and higher mechanical strength, with lower loss compared to polyester resin matrix. The composite showed lower mechanical behavior of the resin matrix for all the formulations studied except the impact resistance. The SEM showed a good adhesion between the layers of TPA and polyester resin matrix, without the presence of micro voids in the matrix confirming the efficient manufacturing process of the samples for characterization. The composite proposed proved to be viable for the fabrication of structures with low requests from mechanical stresses, and as demonstrated for the manufacture of solar and wind prototypes, and packaging, shelving, decorative items, crafts and shelves, with good visual appearance.
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We provide new evidence on sea surface temperature (SST) variations and paleoceanographic/paleoenvironmental changes over the past 1500 years for the north Aegean Sea (NE Mediterranean). The reconstructions are based on multiproxy analyses, obtained from the high resolution (decadal to multi-decadal) marine record M2 retrieved from the Athos basin. Reconstructed SSTs show an increase from ca. 850 to 950 AD and from ca. 1100 to 1300 AD. A cooling phase of almost 1.5 °C is observed from ca. 1600 AD to 1700 AD. This seems to have been the starting point of a continuous SST warming trend until the end of the reconstructed period, interrupted by two prominent cooling events at 1832 ± 15 AD and 1995 ± 1 AD. Application of an adaptive Kernel smoothing suggests that the current warming in the reconstructed SSTs of the north Aegean might be unprecedented in the context of the past 1500 years. Internal variability in atmospheric/oceanic circulations systems as well as external forcing as solar radiation and volcanic activity could have affected temperature variations in the north Aegean Sea over the past 1500 years. The marked temperature drop of approximately ~2 °C at 1832 ± 15 yr AD could be related to the 1809 ?D 'unknown' and the 1815 AD Tambora volcanic eruptions. Paleoenvironmental proxy-indices of the M2 record show enhanced riverine/continental inputs in the northern Aegean after ca. 1450 AD. The paleoclimatic evidence derived from the M2 record is combined with a socio-environmental study of the history of the north Aegean region. We show that the cultivation of temperature-sensitive crops, i.e. walnut, vine and olive, co-occurred with stable and warmer temperatures, while its end coincided with a significant episode of cooler temperatures. Periods of agricultural growth in Macedonia coincide with periods of warmer and more stable SSTs, but further exploration is required in order to identify the causal links behind the observed phenomena. The Black Death likely caused major changes in agricultural activity in the north Aegean region, as reflected in the pollen data from land sites of Macedonia and the M2 proxy-reconstructions. Finally, we conclude that the early modern peaks in mountain vegetation in the Rhodope and Macedonia highlands, visible also in the M2 record, were very likely climate-driven.
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Organic geochemical studies on samples from Holes 487, 488, and 490 in the southern Mexico Middle America Trench provided an opportunity to characterize the organic fraction of the sedimentary section in an active trench environment and to project the petroleum-producing potential of the extracted lipid fractions. The samples were geologically young and of shallow burial history. Samples from Hole 487, located on the oceanic plate, range in age from late Miocene to middlelate Pleistocene. Samples from Hole 488, representing undifferentiated Quaternary sediment, were collected on the landward side of the lower trench slope. Miocene(?) to Quaternary sediments from Hole 490 were obtained from the upper slope immediately seaward of the inferred location of the continental crust.
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Development of Internet-of-Services will be hampered by heterogeneous Internet-of-Things infrastructures, such as inconsistency in communicating with participating objects, connectivity between them, topology definition & data transfer, access via cloud computing for data storage etc. Our proposed solutions are applicable to a random topology scenario that allow establishing of multi-operational sensor networks out of single networks and/or single service networks with the participation of multiple networks; thus allowing virtual links to be created and resources to be shared. The designed layers are context-aware, application-oriented, and capable of representing physical objects to a management system, along with discovery of services. The reliability issue is addressed by deploying IETF supported IEEE 802.15.4 network model for low-rate wireless personal networks. Flow- sensor succeeded better results in comparison to the typical - sensor from reachability, throughput, energy consumption and diversity gain viewpoint and through allowing the multicast groups into maximum number, performances can be improved.
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Thesis (Master's)--University of Washington, 2016-08
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Strandings of live or dead aquatic mammals constitute an important instrument to provide information regarding the occurrence, biology and ecology of these species. The aim of this study was to register the stranded species of cetaceans, the frequency and the spatial-temporal distribution of theses strandings during the period of 1984 to 2005, in the coast of Rio Grande do Norte. Data was acquired through the monitoring of strandings in the north, north-west and south coast of RN, and through information obtained from institutions and newspaper archives of the State. A total of 122 strandings of cetaceans were registered along the coast of Rio Grande do Norte. Of the 14 species of cetaceans registered, four species had higher frequencies: Sotalia guianensis (n= 65), Steno bredanensis (n = 6), Globicephala macrorhynchus (n = 6) and Physeter macrocephalus (n = 7). Out of 118 strandings, 93 occurred in the south coast (78.8 %), 23 in the north coast (19.5%) and 2 (1.7%) in the north-west coast of the State. The highest frequency of strandings occurred during the months of August to March and the maximum number of strandings occurred from 2000 onwards, as a consequence of the intense monitoring of the Pequenos Cetáceos Project in Rio Grande do Norte
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O cinema, desde o seu início, teve uma constante necessidade de se promover. Os filmes, para além de serem um produto cultural, são também um produto que necessita de rentabilidade, tornando fulcral uma receita adequada de bilhetes vendidos para garantir retorno no dinheiro gasto à produção dos mesmos. Sendo assim, os filmes exibidos em salas de cinema são anunciados semanas ou até meses antes da sua estreia, criando, desta forma, complexas campanhas de marketing e publicidade de forma a garantir que o maior número de pessoas tome conhecimento da sua existência. No presente projeto procura-se conhecer e compreender os fatores determinantes na frequência de ida às salas de cinema, tendo como objetivo principal analisar a promoção de cinema, cada um dos meios de divulgação cinematográficos e o seu respetivo papel comunicativo, na tentativa de se perceber de que forma estes se destacam em modos promocionais, incentivando o consumidor a visionar um filme numa sala de cinema. O estudo desenvolveu-se através de uma análise conceptual teórica da promoção e consumo de cinema, dos seus respetivos meios de divulgação, e da utilização de uma abordagem quantitativa que consistiu na análise e interpretação dos resultados de um questionário que contou com a participação de 380 sujeitos. O questionário procurou compreender os hábitos de obtenção de informação cinematográfica dos inquiridos, bem como os fatores que os influenciam a ver filmes nas salas de cinema e os meios de divulgação que mais impacto causam nas suas preferências. A análise dos dados recolhidos revela que existe uma ligação entre a ida às salas de cinema e a ideia da crescente falta de tempo das pessoas, associada ao reduzido poder de compra. Já no que se refere aos fatores e meios de divulgação determinantes na escolha de filmes, os participantes destacaram a Internet e o “bocaa- boca” como principais influenciadores. Os resultados alcançados sugerem assim tendências que devem ser consideradas na implementação de uma estratégia cuja intenção seja a do aumento da frequência da ida às salas de cinema.