The role of asymptotic functions in network optimization and feasibility studies

Solutions to network optimization problems have greatly benefited from developments in nonlinear analysis, and, in particular, from developments in convex optimization. A key concept that has made convex and nonconvex analysis an important tool in science and engineering is the notion of asymptotic function, which is often hidden in many influential studies on nonlinear analysis and related fields. Therefore, we can also expect that asymptotic functions are deeply connected to many results in the wireless domain, even though they are rarely mentioned in the wireless literature. In this study, we show connections of this type. By doing so, we explain many properties of centralized and distributed solutions to wireless resource allocation problems within a unified framework, and we also generalize and unify existing approaches to feasibility analysis of network designs. In particular, we show sufficient and necessary conditions for mappings widely used in wireless communication problems (more precisely, the class of standard interference mappings) to have a fixed point. Furthermore, we derive fundamental bounds on the utility and the energy efficiency that can be achieved by solving a large family of max-min utility optimization problems in wireless networks.Comment: GlobalSIP 2017 (to appear

Diffraction and an infrared finite gluon propagator

We discuss some phenomenological applications of an infrared finite gluon propagator characterized by a dynamically generated gluon mass. In particular we compute the effect of the dynamical gluon mass on $pp$ and ${\bar{p}}p$ diffractive scattering. We also show how the data on $\gamma p$ photoproduction and hadronic $\gamma \gamma$ reactions can be derived from the $pp$ and $\bar{p}p$ forward scattering amplitudes by assuming vector meson dominance and the additive quark model.Comment: 4 pages, 7 figures, added references and figures, changed structure. Contribution to Proceedings of XVIIIth Reuniao de Trabalho sobre Interacoes Hadronicas, Sao Paulo, Brazil, 22-24 May, 200

All-strain based valley filter in graphene nanoribbons using snake states

A pseudo-magnetic field kink can be realized along a graphene nanoribbon using strain engineering. Electron transport along this kink is governed by snake states that are characterized by a single propagation direction. Those pseudo-magnetic fields point towards opposite directions in the K and K' valleys, leading to valley polarized snake states. In a graphene nanoribbon with armchair edges this effect results in a valley filter that is based only on strain engineering. We discuss how to maximize this valley filtering by adjusting the parameters that define the stress distribution along the graphene ribbon.Comment: 8 pages, 6 figure

Scalar form factors and nuclear interactions

The scalar-isoscalar term in the two-pion exchange $NN$ potential is abnormally large and does not respect the hierarchy of effects predicted by chiral perturbation theory. We argue that this anomaly is associated with non-perturbative effects, which are also present in the $\pi N$ scalar form factor.Comment: Talk given at the 20EFB, Pisa, Italy, September 2007. 3 pages and 4 figure

Dietas contendo silagem de milho (Zea maiz L.) e feno de capim-Tifton 85 (Cynodon spp.) em diferentes proporções para bovinos.

Avaliaram-se o consumo, a digestibilidade, o pH e concentração de amônia ruminais e a taxa de passagem em bovinos alimentados com dietas contendo feno de capim-tifton 85 (TIF) e silagem de milho (SM) em diferentes proporções. Utilizaram-se quatro animais castrados, com peso médio de 523kg, fistulados no rúmen, distribuídos em um quadrado latino 4 x 4, recebendo 60% de volumoso e 40% de concentrado, na base da matéria seca. O volumoso consistiu das seguintes proporções (%): 100 TIF:0 SM; 67 TIF:33 SM; 33 TIF:67 SM e 0 TIF:100 SM. Os consumos de matéria seca (MS), de matéria orgânica (MO) e de matéria orgânica digestível (MOD), de proteína bruta (PB), de fibra em detergente neutro (FDN) e de carboidratos totais (CHOT) e digeríveis (CHOD) não foram influenciados pelas diferentes proporções de feno de capim-tifton 85: silagem de milho nas dietas, registrando-se valores médios de 9,2; 8,7; 6,4; 1,1; 3,7; 7,3 e 5,4 kg/dia, respectivamente. O consumo de extrato etéreo (EE) elevou linearmente com o aumento da silagem de milho nas dietas. As digestibilidades aparentes da MS, MO, PB, EE e CHO também não foram influenciadas pelas diferentes proporções de silagem de milho, obtendo-se, respectivamente, valores médios de 71,8; 73,0; 69,5; 69,2 e 73,9%. Para a digestibilidade da FDN, observou-se efeito quadrático, estimando-se valor máximo de 65,2% para dietas contendo 30,98% de silagem de milho. Estimou-se concentração máxima de amônia de 12,0 mg/100 ml e valor mínimo de pH de 5,98 às 2,44 e 6,82 horas após a alimentação, respectivamente. A taxa de passagem não foi influenciada pelas diferentes proporções de feno:silagem, no volumoso, apresentando valor médio de 4,2%/hora. Corn silage and Tifton 85 Bermudagrass Hay-Based Diets for Steers. ABSTRACT - The intake, digestibility, ruminal pH and ammonia concentrations and passage rate were evaluated in steers fed corn silage (CS) and Tifton 85 bermudagrass hay (T85H)-based diets, at different forage proportions. Four rumen fistulated steers with 523 kg of live weight were used in a 4x4 latin square design, and fed diets containing 60:40 forage:concentrate proportions in dry matter basis. The forage portion consisted of: 100 T85H:0 CS; 67 T85H:33 CS; 33 T85H:67 CS and 0 T85H:100 CS. The dry matter (DM), organic matter (OM), digestible organic matter (DOM), crude protein (CP), neutral detergent fiber (NDF), total carbohydrates (TC) and total digestible carbohydrates (TDC) intakes were not affected by different T85H: CS proportions and averaged 9.2, 8.7, 6.4, 1.1, 3.7, 7.3 and 5.4 kg/day, respectively. The ethereal extract (EE) intake increased with increasing on corn silage proportion of the diets. The DM, OM, CP, EE and TC apparent digestibilities were not affected by increasing percentage of corn silage on rations and averaged 71.8, 73.0, 69.5, 69.2 and 73,9%, respectively. There was a quadratic effect for NDF digestibility, with maximum value of 65.2% for diets with 30.98% of CS. The N-ammonia maximum content (12.0 mg/100 ml) and minimum value of pH (5.98) were estimated 2.44 and 6.82 hours after feeding, respectively. The passage rate, which was not affected by changing T85H:CS proportions in the forage, averaged 4.2 %/hour

Pion-delta sigma-term

We use a configuration space chiral model in order to evaluate nucleon and delta sigma-terms. Analytic expressions are consistent with chiral counting rules and give rise to expected non-analytic terms in the chiral limit. We obtain the results $\sigma_N=46$ MeV and $\sigma_{\Delta}=32$ MeV, which are very close to values extracted from experiment and produced by other groups.Comment: 18 pages, 4 figure

Diversidade e potencialidades do bioma caatinga sob diferentes manejos no assentamento Vista Alegre-CE.

Resumo: O manejo da Caatinga através do raleamento tem favorecido o aumento da produção de forragem e manutenção da biodiversidade. Conhecer as espécies vegetais presentes no ecossistema, seu uso e potencial dentro do sistema de produção é essencial para que se possa produzir de forma sustentável. Este trabalho teve como objetivo levantar as famílias botânicas e o potencial produtivo das espécies lenhosas em áreas de Caatinga raleada e nativa no semiárido cearense. A pesquisa foi conduzida no Assentamento Vista Alegre no município de Quixeramobim, no Ceará, no período de dezembro de 2011 a julho de 2012, sendo utilizadas as demarcações de oito parcelas de 100 m2 (10 m x 10 m) de modo aleatório por hectare em cada área. Foram mensuradas a ocorrência e a densidade das espécies. Foram identificadas cinco espécies com potencial forrageiro na área de Caatinga raleada para fins pastoris, sendo que na área de caatinga raleada destinada para exploração da apicultura foram identificadas três espécies que se destinam para fins apícolas. Por fim, na área de caatinga nativa foram identificadas sete espécies com potencial apícola. O raleamento revela-se uma alternativa promissora como prática de manejo sustentável da Caatinga. [Diversity and potential of the caatinga in Vista Alegre settlement due to the different types of vegetation management]. Abstract: The management of Caatinga through thinning has favored the increase offorage production and maintenance of biodiversity. Knowing the plant species in the ecosystem, their use and potential within the production system is essential so that we can sustainably produce. This study aimed to identify the botanical families and the productive potential of woody species in Caatinga areas in thinned and native semiarid Ceará. This trial was carried out in Vista Alegre settlement in Quixeramobim, Ceará, from December 2011 to July 2012, and used the demarcations eight plots of 100 m2 (10 m x 10 m) randomly per hectare in each field. We measured the occurrence and density of species. We identified five species with forage potential in the area of Caatinga thinned for pastoral purposes, and in the area of thinned Caatinga intended for beekeeping exploration identified three species that are intended for purposes bee. Finally, in the area of native Caatinga species identified seven potential bee keeping. The thinning is revealed as a promising practice of sustainable management of the Caating

Práticas agroecológicas de convivência com semiárido adotadas por agricultores familiares no sertão cearense.

Resumo: O modelo de agricultura adotado no Nordeste brasileiro tem provocado degradação da caatinga, reduzindo a capacidade produtiva do solo, geração de renda e a insegurança alimentar na região semiárida. A preservação da caatinga, fixação do homem ao campo, seu bem-estar, aliados à geração de renda, são possíveis fatores de sustentabilidade e de desenvolvimento local. O objetivo do trabalho foi avaliar as práticas agroecológicas adotadas pelos agricultores familiares do assentamento Vista Alegre, em Quixeramobim, no Ceará. Foram aplicados 18 questionários semi-estruturados baseado em técnicas de Diagnóstico Rural Participativo. Todas as famílias adotam a pratica da adubação orgânica, pelo uso do esterco do rebanho, cerca de 90% dos agricultores não desmatam, quase 80% dos assentados não efetuam queimadas, cerca de 90% dos produtores não usam agrotóxicos. Estas práticas parecem ser essenciais para o desempenho da agricultura familiar, manutenção e melhoria da fertilidade dos agroecossistemas, sendo ferramentas importantes para a sustentabilidade da produção agrícola, e em um menor nível de dependência de insumos externos e redução dos custos da produção. [Agroecological practices using by smallholders in the brazilian semiarid]. Abstract: The agricultural model adopted in the Brazilian Northeast has caused degradation of the savanna, reducing the productive capacity of the soil, income generation and food insecurity in the semiarid region. The preservation of the savanna, fixing the man in the field, their well-being, combined with income generation, are possible factors of sustainability and local development. The aim of this study was to evaluate the agroecological practices adopted by farmers nesting Vista Alegre in Quixeramobim, Ceará. Were applied to 18 semi-structured questionnaires based on techniques of Participatory Rural Appraisal. All families have adopted the practice of organic manure, the use of manure from the herd, about 90% of farmers do not deforest, almost 80% of the settlers do not make fires, about 90% of farmers do not use pesticides. These practices appear to be essential for the performance of family farming, maintaining and improving the fertility of agroecosystems, with important tools for sustainable agricultural production, and a lower level of dependence on external inputs and reduction of production costs