Sleep Mode Analysis via Workload Decomposition

The goal of this paper is to establish a general approach for analyzing queueing models with repeated inhomogeneous vacations. The server goes on for a vacation if the inactivity prolongs more than the vacation trigger duration. Once the system enters in vacation mode, it may continue for several consecutive vacations. At the end of a vacation, the server goes on another vacation, possibly with a different probability distribution; if during the previous vacation there have been no arrivals. However the system enters in vacation mode only if the inactivity is persisted beyond defined trigger duration. In order to get an insight on the influence of parameters on the performance, we choose to study a simple M/G/1 queue (Poisson arrivals and general independent service times) which has the advantage of being tractable analytically. The theoretical model is applied to the problem of power saving for mobile devices in which the sleep durations of a device correspond to the vacations of the server. Various system performance metrics such as the frame response time and the economy of energy are derived. A constrained optimization problem is formulated to maximize the economy of energy achieved in power save mode, with constraints as QoS conditions to be met. An illustration of the proposed methods is shown with a WiMAX system scenario to obtain design parameters for better performance. Our analysis allows us not only to optimize the system parameters for a given traffic intensity but also to propose parameters that provide the best performance under worst case conditions

Unilateral Altruism in Network Routing Games with Atomic Players

We study a routing game in which one of the players unilaterally acts altruistically by taking into consideration the latency cost of other players as well as his own. By not playing selfishly, a player can not only improve the other players' equilibrium utility but also improve his own equilibrium utility. To quantify the effect, we define a metric called the Value of Unilateral Altruism (VoU) to be the ratio of the equilibrium utility of the altruistic user to the equilibrium utility he would have received in Nash equilibrium if he were selfish. We show by example that the VoU, in a game with nonlinear latency functions and atomic players, can be arbitrarily large. Since the Nash equilibrium social welfare of this example is arbitrarily far from social optimum, this example also has a Price of Anarchy (PoA) that is unbounded. The example is driven by there being a small number of players since the same example with non-atomic players yields a Nash equilibrium that is fully efficient

Supplementing government initiatives for universal access to sanitation through a district-wide approach

This paper describes the model of Districti Wide Approach that WaterAid is following in Madhya Pradesh and Chhattisgarh as a model for universal coverage of sanitation. The Government of India has a political commitment to meet the universal access to sanitation target by 2019. However, the past experience of nearly three decades very clearly show that there are several hurdles and gaps that needs to be overcome to ensure that this happens. We believe that universal access can happen and it can happen if efforts are put in to strengthen the existing government mechanisms and through networking with multi-stakeholders on the agenda of sanitation. In Madhya Pradesh and Chhattisgarh, we have attempted district wide approach using six broad components – IEC/BCC, Capacity building, Rights based approach, Influencing policies, strengthening governance systems and demonstration especially to address vulnerabilities

Effect of salinization of soil on emergence, growth and survival of seedlings of Acacia nilotica

RAMOLIYA, P. J. & PANDEY, A.N. 2002. Efecto de la salinización en el brote, crecimiento y supervivencia de Acacia nilotica. Bot. Complutensis 26: 105-119. Se estudiaron los efectos de la salinización del suelo sobre la emergencia, el crecimiento y los atributos fisiológicos de plántulas de Acacia nilotica (L.) Del. (Mimosaceae). Se añadió al suelo una mezcla de cloruros y sulfatos de Na, K, Ca y Mg, y se mantuvo la salinidad a 4.1, 6.2, 8.1, 9.9, 12.2 y 14.3 dSm–1. La relación obtenida entre el porcentaje de germinación de semillas y la concentración de sal fue negativa. Las plántulas no emergieron cuando la salinidad excedió 12.2 dSm–1. Los resultados sugieren que esta especie arbórea tolera la sal en la germinación. Las plántulas sobrevivieron y crecieron hasta con una salinidad de 12.2 dSm–1 y eventualmente esta especie también tolera la sal en el estado de plántula. La elongación del tallo y de la raíz fue retrasada al incrementarse el estrés salino. Sin embargo, esta especie tiene una tendencia al crecimiento rápido de la raíz, y las raíces son capaces de extraer agua de suelos salinos muy secos (6,8% humedad). Las raíces y tallos jóvenes fueron los más tolerantes al estrés salino entre los tejidos, y después las raíces viejas y las hojas a continuación. La máxima reducción en producción de masa seca en respuesta al aumento de estrés salino la exhibió el tejido de la hoja. Sin embargo, se encontró que la producción de raíces jóvenes y la muerte de raíces viejas fue un proceso continuo, y, aparentemente, las plantas usan este proceso como un mecanismo de evasión, para deshacerse del exceso de iones y retrasar los daños de la acumulación de iones en este tejido. Este fenómeno, denominado «renovación de raíces finas» resulta de importancia entre los mecanismos de tolerancia de sal. La capacidad de esta planta para prosperar en regiones secas es debida también a las características xeromórficas de sus hojas.RAMOLIYA, P. J. & PANDEY, A.N. 2002. Effect of salinization on emergence, growth and survival of seedlings of Acacia nilotica. Bot. Complutensis 26: 105-119. Effects of salinization of soil on emergence, growth and physiological attributes of seedlings of Acacia nilotica (Linn.) Del. (Mimosaceae) were studied. A mixture of chlorides and sulphates of Na, K, Ca and Mg was added to the soil and salinity was maintained at 4.1, 6.2, 8.1, 9.9, 12.2 and 14.3 dS m–1. A negative relationship between percent seed germination and salt concentration was obtained. Seedlings did not emerge when soil salinity exceeded 12.2 dS m–1. Results suggested that this tree species is salt tolerant at seed germination stage. Seedlings survived and grew up to soil salinity 12.2 dS m–1 and eventually this species is salt tolerant at seedling stage too. Elongation of stem and root was retarded by increasing salt stress. However, this species has a tendency for rapid root extension and roots are able to extract water from very dry saline soil (6.8 % moisture). Among the tissues, young roots and stem were most tolerant to salt stress and were followed by old roots and leaf successively. Leaf tissue exhibited maximum reduction in dry mass production in response to increasing salt stress. However, production of young roots and death of old roots were found to be continuous and plants apparently use this process as an avoidance mechanism to remove excess ions and delay onset of ion accumulation in this tissue. This phenomenon, designated «fine root turnover» assumes an importance to the mechanisms of salt tolerance. The ability of this plant to thrive in dry regions is further conferred by the xeromorphic features of its leaves

3D Printed Graphene-Coated Flexible Lattice as Piezoresistive Pressure Sensor

Piezoresistive sponges represent a popular design for highly flexible pressure sensors and are typically fabricated using templating methods. In this work, we used stereolithography (SLA) to 3D-print an elastomeric body-centered cubic (BCC) lattice structure with a relative density of 21% and an elastic modulus of 31.5 kPa. The lattice was dip-coated with graphene nanoplatelets to realize a piezoresistive pressure sensor with excellent performance (gauge factor = 3.25, sensitivity = 0.1 kPa-1), high deformability (up to 60 % strain), and repeatability. The novel approach outlined in this work offers greater control over the microstructure and can be used to fabricate sensors with tunable properties