Sleep-mode operation of a Mobile Subscriber Station (MSS) in IEEE 802.16e effectively saves energy consumption; however, it induces frame response delay. In this letter, we propose an algorithm to quickly find the optimal value of the final sleep interval in sleep-mode in order to minimize energy consumption with respect to a given frame response delay constraint. The validations of our propose...

Routing in Wireless Sensor Networks (WSNs) is a very challenging task due to the large number of nodes, their mobility and lack of proper infrastructure. Since the sensors are battery powered devices, energy efficiency is considered as one of the main factors in designing routing protocols in WSNs. Most of energy-aware routing protocols are mere energy savers that attempt to decrease the energy...

We test for precautionary saving and excess sensitivity of consumption to predicted income growth using a 1989-93 panel survey of Italian households that has measures of subjective income and inflation expectations. These expectations provide a powerful instrument for predicting income growth. The empirical specification controls for predictable changes in labor supply and allows a fairly gener...

Aging populations are leading countries worldwide to social security reforms. Many countries are moving from pay-as-you-go to personal retirement account (PRA) systems because of their financial sustainability and positive impact on private savings. PRA systems boost private savings at a macro level by converting a government liability into financial wealth managed by private fund managers. How...

The high energy consumption in cloud data centers has become an urgent problem. The scale and architecture of cloud data centers are growing increasingly immense and complex in recent years, which bring more severe challenges on the energy consumption management. This paper proposes new approaches for virtual machines (VMs) placement based on CPU frequency scaling. In the stage of initial VM pl...

The explosive development of ICT (information and communication technology) industry has emerged as one of the major sources of world energy consumption. Therefore, this paper concerns about the BS (base station) energy saving issue, for most energy consumption of the communication network comes from the BSs and the core network. Particularly, we consider dynamically turning off certain BSs whe...

Studies of ad hoc wireless networks are rapidly gaining popularity due to its varied and innovative applications. Medium Access Control (MAC) protocols in such networks are responsible to coordinate access among active nodes. Wireless nodes are largely powered by batteries which restricts the quantity of energy available to the nodes. Routing for wireless nodes is incorporated with power saving...

The topic of energy saving in buildings is increasingly raising the interest of researchers for its practical outcomes in terms of economic advantages, and long-term environmental sustainability. Many sensory devices are currently available that allow precise monitoring of every physical quantity; in particular it is possible to obtain estimates of energy consumption which can be used to enact ...

The “Green Computing,” is especially important and timely. As computing becomes increasingly pervasive, the energy consumption attributable to computing is climbing, despite the clarion call to action to reduce consumption and reverse greenhouse effects. A high performance-computing cluster is a set of computers gathered together and connected with the intent of merging their processing power t...