The Relativized Second Eigenvalue Conjecture of Alon

We prove a relativization of the Alon Second Eigenvalue Conjecture for all $d$-regular base graphs, $B$, with $d\ge 3$: for any $\epsilon>0$, we show that a random covering map of degree $n$ to $B$ has a new eigenvalue greater than $2\sqrt{d-1}+\epsilon$ in absolute value with probability $O(1/n)$. Furthermore, if $B$ is a Ramanujan graph, we show that this probability is proportional to $n^{-{\eta_{\rm \,fund}}(B)}$, where ${\eta_{\rm \,fund}}(B)$ is an integer depending on $B$, which can be computed by a finite algorithm for any fixed $B$. For any $d$-regular graph, $B$, ${\eta_{\rm \,fund}}(B)$ is greater than $\sqrt{d-1}$. Our proof introduces a number of ideas that simplify and strengthen the methods of Friedman's proof of the original conjecture of Alon. The most significant new idea is that of a ``certified trace,'' which is not only greatly simplifies our trace methods, but is the reason we can obtain the $n^{-{\eta_{\rm \,fund}}(B)}$ estimate above. This estimate represents an improvement over Friedman's results of the original Alon conjecture for random $d$-regular graphs, for certain values of $d$

EVALUATION OF FRESH AND FLESHY CUCUMBER QUALITY AND SHELF-LIFE USING CHARCOAL COOLER BIN IN THE TROPICS

Adiabatic evaporative cooling is a concept and process adopted for extending the shelf-life of fresh fruits and vegetables in the tropics. This study evaluated Charcoal Cooler Bin (CCB) performance and its effects on the quality and shelf-life of cucumbers. The storage microclimate and ambient conditions (air temperature and relative humidity) were measured using a data logger. By monitoring the physiological and quality parameters, the effects of the storage media: CCB, open-air, refrigerator and laboratory conditions on the storability of cucumber fruits, and the effectiveness of the CCB for fresh cucumber preservation through percentage weight loss, visual quality, degree of shrivelling, colour changes and life of expectancy were evaluated. The CCB markedly maintained the freshness, and reduced weight loss (with a weight loss of 3.4696% after the storage period relative to cucumber samples stored in the refrigerator, laboratory and open-air conditions with 8.4176%, 9.8260%, and 11.2696%, respectively) and extended the shelf-life of cucumbers fruits at CCB environmental conditions. Therefore, CCB is a passive system that is an inexpensive and reliable storage medium for sustainably reducing postharvest losses

Estimating Price Premiums for Breads Marketed as “Low-Carbohydrate Breadsâ€

Retail data are used in a hedonic pricing framework to estimate the premium paid for the “low-carbohydrate†attribute and other attributes of bread at grocery and non-grocery stores in a regional market. Results show that consumer willingness to pay is influenced by the “low-carbohydrate†attribute as well as by sugar, fiber, and fat content; serving size; and size of loaf. Implicit price premiums vary significantly by retail location. However, price differentials may be compounded by the absence of an acceptable definition for low-carbohydrate foods.Demand and Price Analysis, Marketing,

Measuring volatility persistence in leveraged loan markets in the presence of structural breaks.

This paper examines volatility persistence in leverage loan market price series for Australia, Canada, Europe, Japan, Singapore, UK and USA in the presence of structural breaks. To the best of our knowledge, this is the first empirical study to examine volatility persistence in the leveraged loan markets. To this end, using fractional integration methods, the results indicate that both absolute and squared returns display long memory features, with orders of integration confirming the long memory hypothesis. However, after accounting for structural breaks, we find a reduction in the degree of persistence in the leveraged loan market. The evidence of persistence in volatility implies that market participants who want to make gains across trading scales need to factor the persistence properties of leveraged loan price series in their valuation and forecasting models since that will help improve long-term volatility market forecasts and optimal hedging decisions.post-print759 K

Behavior of early warnings near the critical temperature in the two-dimensional Ising model

Among the properties that are common to complex systems, the presence of critical thresholds in the dynamics of the system is one of the most important. Recently, there has been interest in the universalities that occur in the behavior of systems near critical points. These universal properties make it possible to estimate how far a system is from a critical threshold. Several early-warning signals have been reported in time series representing systems near catastrophic shifts. The proper understanding of these early-warnings may allow the prediction and perhaps control of these dramatic shifts in a wide variety of systems. In this paper we analyze this universal behavior for a system that is a paradigm of phase transitions, the Ising model. We study the behavior of the early-warning signals and the way the temporal correlations of the system increase when the system is near the critical point.Comment: 20 pages, 8 figures, Submitted to PLOS ONE on Oct. 20th 2014. PONE-D-14-4718

Government Capital Expenditure and Economic Growth in Nigeria: Any Lesson from Disaggregated Functional Analysis?

This study investigates the influence of disaggregated functional government capital expenditure on economic growth in Nigeria between the periods of 1970 to 2013, using error correction technique of estimation on the data of the economy. The results indicated that the long run relationship exists between the components of public capital expenditure and economic growth. However, the results revealed that disaggregated functional capital expenditure of government did not generate the intending growth to real economic activities. More specifically, capital expenditure on economic service was actually negatively affecting the growth of the economy, though insignificant, implying that the economy did not benefit from such spending. This development in Nigerian economy contravenes the growth theories. We therefore recommend that Nigerian government should adequately monitor all her spending in the economy to achieve the purposes for which the funds are released. Again, all the government projects and allocations should be well supervised to reduce the costs inflated by government officials and contractors. Keywords: Government, Expenditure, Error Correction, Economic Growth, Estimatio

Improved Multiplierless Architecture for Header Detection in DVB-S2 Standard

International audienceOne of the first processing steps in a DVB-S2 signal receiver is the detection of frame's header. Recently, an architecture using only the phase information of the received samples was proposed. In this paper several optimization in algo-rithm/architecture are proposed, leading to better performance and reduced hardware complexity. For an SNR of-3 dB, the probability of miss detection of the header detector is reduced from 0.7 down to 0.52 for a constant false alarm probability of 10 −6

Poster Abstract: Interconnecting Low-Power Wireless and Power-Line Communications using IPv6

Wireless sensor networks for building automation and energy management has made great progress in recent years, but the inherent indoor radio range limitations can make communication unpredictable and system deployments difficult. Low-power radio can be combined with low-power Power-Line Communication (PLC) to extend the range and predictability of indoor communication for building management and automation systems. We take the first steps towards exploring the system implications for integration of low-power wireless and PLC in the same network. We leverage IPv6, which allow networks to exist over multiple physical communication media as well as the RPL routing protocol for low-power lossy networks

Enhancing Strength Properties of Rubberized Concrete using Waste Cement Sacks

Low flexibility and brittleness of ordinary concrete limits its use as construction material for buildings prone to earthquake ground vibrations. Rubberized concrete which possesses the needed ductility on the other hand is however of low strength and durability. This study utilized waste polypropylene sacks used for packaging cement. The sacks were used in form of confinements to enhance the strength/ductility of rubberized concrete. Concrete cylinders, cubes and beams at different replacements levels of coarse aggregate with waste tire rubber chips(WTRC) (at 0, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100% by volumes) were cast and tested for fresh and hardened properties such as slump, compressive strength, flexural strength, and deformation behaviour. The result showed proportional reduction in strengths with increasing replacement of WTRC. Ductile and elasto-plastic deformations were exhibited by WTRC concretes. The use of waste cement sacks confinement as a means of overcoming the reduced strength of the rubberized concrete proved highly feasible and economic for the cylindrical specimens. Optimum performance in failure load (for confined specimens) was obtained at 80% WTRC replacement. The confined 80% WTRC failure load was 45.5 KN, approximately 300% increase in failure load of the unconfined 80% WTRC concrete. This indicates that the use of waste cement sacks to confine rubberized concrete effectively negates the decrease in strength, and retains the advantages of increased ductility and energy-dissipation that characterizes rubberized concrete