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21.
We consider selfish routing over a network consisting of m parallel
links through which $n$ selfish users route their traffic trying to
minimize their own expected latency. We study the class of mixed
strategies in which the expected latency through each link is at most
a constant multiple of the optimum maximum latency had global
regulation been available. For the case of uniform links it is known
that all Nash equilibria belong to this class of strategies. We are
interested in bounding the coordination ratio (or price of anarchy) of
these strategies defined as the worst-case ratio of the maximum (over
all links) expected latency over the optimum maximum latency. The load
balancing aspect of the problem immediately implies a lower bound
Ω(ln m ln ln m) of the coordination
ratio. We give a tight (up to a multiplicative constant) upper bound.
To show the upper bound, we analyze a variant of the classical balls
and bins problem, in which balls with arbitrary weights are placed
into bins according to arbitrary probability distributions. At the
heart of our approach is a new probabilistic tool that we call ball
fusion; this tool is used to reduce the variant of the problem where
balls bear weights to the classical version (with no weights). Ball
fusion applies to more general settings such as links with arbitrary
capacities and other latency functions. 相似文献
22.
Aldri L. dos Santos Elias P. Duarte Jr. Glenn M. Keeni 《Journal of Network and Systems Management》2004,12(2):191-213
This paper presents a new clustering architecture for SNMP agents that supports semi-active replication of managed objects. A cluster of agents provides fault-tolerant object functionality: replicated managed objects of a crashed agent of a given cluster may be accessed through a peer cluster. The proposed architecture is structured in three layers. The lower layer corresponds to the managed objects at the network elements. The middle layer contains management entities called clusters that monitor and replicate managed objects. The upper layer allows the definition of management clusters as well as the relationship between clusters. A practical tool was implemented and is presented. The impact of replication on network performance is evaluated as well as a probabilistic analysis of replicated object consistency. 相似文献
23.
Zilla Sinuany-Stern Nachum Finger Elias Kligler 《Computers, Environment and Urban Systems》1986,11(4)
This paper provides a model for finding the optimal thinning policy in a pine forest (Pinus halepensis) in Israel. The model simulates the growth of a pine forest stand for timber, under various thinning policies. The annual growth functions are estimated via polynomial regression analysis. The dependent variable is the timber volume of the stand and the explanatory variable is the mean growing space per tree over time. The observations were made over the life span of five experimental parcels in a pine forest in Israel. 相似文献
24.
Role of physical structures in bulk oils on lipid oxidation 总被引:1,自引:0,他引:1
Chaiyasit W Elias RJ McClements DJ Decker EA 《Critical reviews in food science and nutrition》2007,47(3):299-317
Lipid oxidation is important to food manufacturers especially when they increase unsaturated lipids in their products to improve nutritional profiles. Unfortunately, the number of antioxidants available to food manufacturers to control oxidative rancidity is limited and the approval of new antioxidants is unlikely due to economic barriers in obtaining government approval for new food additives. Therefore, new antioxidant technologies are needed for food oils. This paper reviews the current knowledge of lipid oxidation in foods with emphasis on how physical properties of food systems impact oxidation chemistry. In particular, the role of association colloids in bulk oils on lipid oxidation chemistry is discussed in an attempt to understand mechanisms of oxidation. Increasing the understanding of how physical properties impact lipid oxidation could lead to the development of novel antioxidant technologies that not only protect the oil against oxidation and increase shelf-life but also allow food manufacturers to include more nutritionally beneficial fatty acids in their products. 相似文献
25.
Mo Huang Dihu Chen Zhao Wang Jianping Guo Elias H. Dagher Bin Xu Ken Xu Hui Ye Weiguo Zheng Zhen Liang Xiaofeng Liang Wesley K. Masenten 《International Journal of Circuit Theory and Applications》2015,43(6):806-821
In this work, a power‐area‐efficient, 3‐band, 2‐RX MIMO, and TD‐LTE (backward compatible with the HSPA+, HSUPA, HSDPA, and TD‐SCDMA) CMOS receiver is presented and implemented in 0.13‐μm CMOS technology. The continuous‐time delta‐sigma A/D converters (CT ?Σ ADCs) are directly coupled to the outputs of the transimpedance amplifiers, eliminating the need of analog anti‐aliasing filters between RX front‐end and ADCs in conventional structures. The strong adjacent channel interference without low‐pass filter attenuation is handled by proper gain control. A low‐power small‐area solution for excess loop delay compensation is implemented in the CT ?Σ ADC. At 20 MHz bandwidth, the CT ?Σ ADC achieves 66 dB dynamic range and 3.5 dB RX chip noise figure is measured. A maximum of 2.4 dB signal‐to‐noise ratio degradation is measured in all the adjacent channel selectivity (ACS) and blocking tests, demonstrating the effectiveness of the strategy against the low‐pass filter removal from the conventional architecture. The receiver dissipates a maximum of 171 mW at 2‐RX MIMO mode. To our best knowledge, it is the first research paper on the design of fully integrated commercial TD‐LTE receiver. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
26.
P. Elias C. Kontoes O. Sykioti A. Avallone S. Van Gorp P. Briole 《International journal of remote sensing》2013,34(14):3079-3086
On 7 September 1999 a magnitude MW = 5.9 earthquake occurred in the Athens area of Greece producing a subsidence of 6–7 cm detected by radar interferometry. This study introduces a processing technique, which produces a clear deformation pattern of the earthquake, mostly released from artefacts due to orbital effects, unwrapping cycle slipping errors and atmospherics disturbances. A set of 17 ERS‐1 and ERS‐2 SAR images acquired between December 1997 and January 2001 has been used. The contribution of each artefact to the interferograms was calculated, both in the frequency and spatial domains. 相似文献
27.
Tiago F. Moreira Rafael R. Nicolino Rodrigo M. Meneses Guilherme V. Fonseca Letícia M. Rodrigues Elias J. Facury Filho Antônio U. Carvalho 《Journal of dairy science》2019,102(11):10369-10378
Cattle lameness is an important welfare concern that also has an economic impact on the dairy industry. It can be a significant problem among pasture-based herds. Our objectives were to identify cow- and herd-level factors related to lameness and hoof lesions in dairy cows grazing year-round in Minas Gerais, Brazil. We performed a cross-sectional study in 48 pasture-based dairy herds, visiting each farm in a single visit. We evaluated 2,262 cows for mobility score (0–3) and 392 cows for hoof lesions. We used a questionnaire and checklist to capture herd management data. All information obtained was used to build multivariable models. The factors associated with lameness were low body condition score, longer time spent in the corral, being kept in paddocks during the drought period, and poor hygiene. For hoof lesions, track features were the most significant factor in determining the likelihood of heel horn erosion, white line fissure, and sole hemorrhage—by more than 3 times. Different factors related to unhygienic conditions such as leg cleanliness, frequency of cleaning, and longer time spent in the corral were associated with infectious hoof lesions. Poor human–animal relationship was related to sole hemorrhage, but patient handling of cows on the track was a protective factor against interdigital hyperplasia. The results of this study suggest that improving hygiene conditions, track features, and cow handling can improve dairy cattle mobility scores in pasture-based farms under tropical conditions. These findings also represent a first step toward planning actions aimed at decreasing lameness and hoof lesions in the studied region. 相似文献
28.
International Regulations of Propolis Quality: Required Assays do not Necessarily Reflect their Polyphenolic‐Related In Vitro Activities 下载免费PDF全文
Raquel Bridi Gloria Montenegro Gabriel Nuñez‐Quijada Ady Giordano Maria Fernanda Morán‐Romero Isaac Jara‐Pezoa Hernán Speisky Elias Atala Camilo López‐Alarcón 《Journal of food science》2015,80(6):C1188-C1195
Propolis has been proposed as a polyphenolic‐rich natural product potentially able to be used for human consumption or even for medicinal proposes. To guarantee a minimum phenolic and flavonoid content and as consequence of their related‐biological activities, international requirements of propolis quality are commonly applied. In this work we assessed phenolic and flavonoid contents of propolis; the antioxidant capacity (toward peroxyl radicals and hypochlorous acid); the ability to generate nitric oxide (NO); and, finally the antimicrobial activity of 6 propolis samples from the VI region of Chile. Our results show that the total phenolic and flavonoid content of propolis samples are not always in agreement with their polyphenolic‐associated in vitro activities. For example, P03 and P06 samples showed the lowest (25 ± 4 GAE/g propolis) and the highest (105 ± 3 GAE/g propolis) total phenolic content, respectively. This was in agreement with flavonoid content and their Oxygen Radical Absorbance Capacity (ORAC) activity. However, this dependence was not observed toward HOCl, NO release and antimicrobial activity. Based on our results, we consider that, in order to guarantee the antioxidant or antimicrobial in vitro effects, the international regulations of propolis quality should contemplate the convenience of incorporating other simple analytical test such as ORAC or antimicrobial tests. 相似文献
29.
Elessandra da Rosa Zavareze Vânia Zanella PintoBruna Klein Shanise Lisie Mello El HalalMoacir Cardoso Elias Carlos Prentice-HernándezAlvaro Renato Guerra Dias 《Food chemistry》2012,132(1):344-350
This study investigated the effects of sodium hypochlorite oxidation and a heat-moisture treatment of potato starch on the physicochemical, pasting and textural properties of potato starches in addition to the water vapour permeability (WVP) and mechanical properties of potato starch films produced from these starches. The carbonyl contents, carboxyl contents, swelling power, solubility, pasting properties and gel texture of the native, oxidised and heat-moisture treated (HMT) starches were evaluated. The films made of native, oxidised and HMT starches were characterised by thickness, water solubility, colour, opacity, mechanical properties and WVP. The oxidised and HMT starches had lower viscosity and swelling power compared to the native starch. The films produced from oxidised potato starch had decreased solubility, elongation and WVP values in addition to increased tensile strength compared to the native starch films. The HMT starch increased the tensile strength and WVP of the starch films compared to the native starch. 相似文献
30.