Search results for "Output"
showing 10 items of 381 documents
Non-cooperative power allocation game with imperfect sensing information for cognitive radio
2012
In this paper, we consider a sensing-based spectrum sharing scenario and present an efficient decentralized algorithm to maximize the total throughput of the cognitive radio users by optimizing jointly both the detection operation and the power allocation, taking into account the influence of the sensing accuracy. This optimization problem can be formulated as a distributed non-cooperative power allocation game, which can be solved by using an alternating direction optimization method. The transmit power budget of the cognitive radio users and the constraint related to the rate-loss of the primary user due to the interference are considered in the scheme. Finally, we use variational inequal…
Structured Output SVM for Remote Sensing Image Classification
2011
Traditional kernel classifiers assume independence among the classification outputs. As a consequence, each misclassification receives the same weight in the loss function. Moreover, the kernel function only takes into account the similarity between input values and ignores possible relationships between the classes to be predicted. These assumptions are not consistent for most of real-life problems. In the particular case of remote sensing data, this is not a good assumption either. Segmentation of images acquired by airborne or satellite sensors is a very active field of research in which one tries to classify a pixel into a predefined set of classes of interest (e.g. water, grass, trees,…
SINR analysis of OFDM systems using a geometry-based underwater acoustic channel model
2015
The Doppler effect is caused by the relative movement between the transmitter (Tx) and the receiver (Rx) and/or the surface motion (waves) in underwater acoustic (UWA) communication systems. The inter-channel interference (ICI) caused by the Doppler effect degrades the performance of orthogonal frequency-division multiplexing (OFDM) systems over UWA channels. This paper is devoted to the ICI plus noise analysis of UWA-OFDM systems over a geometry-based channel model for shallow UWA channels. We carry out the exact calculation of the ICI power, ambient noise power, and required transmit power, as well as their effects on the performance of UWA-OFDM systems. The signal-to-interference ratio (…
Power allocation for two-cell two-user joint transmission
2012
In this paper, we develop a power allocation scheme for the downlink of a two-cell two-user joint transmission system. The objective is to maximize the sum rate under per-cell power constraints. We study a worst case scenario where the carrier phases between the two base stations are un-synchronized, so that joint transmission must be performed without precoding. The derived power allocation scheme is remarkably simple, i.e., each cell transmits with full power to only one user. Note that joint transmission is still possible, when two cells select the same user for data transmission. Moreover, we prove that, in this scenario, the joint transmission case happens with higher probability when …
Reducing Power Consumption of Wireless Networks Through Collaborative DMC Mobile Clusters
2017
Reducing the energy consumption of the wireless network is significantly important to the economic and ecological sustainability of the ICT industry, as high energy consumption may limit the performance of wireless networks and is one of the main network costs. To solve energy consumption problem, especially on the terminal side, a scheme known as distributed mobile cloud (DMC) is considered to be a potential solution. Multiple mobile terminals (MTs) can cooperative to take advantage of good quality links among the MTs to save energy when receiving from the Base Station (BS). In this paper, we aim to find the optimal transmit power to further reduce the energy consumption of DMC. From simul…
Drivers of greenhouse gas emissions in the Baltic States: A structural decomposition analysis
2014
Since the mid-1990s three Baltic States have significantly increased their per capita gross domestic product (GDP) and at the same time have managed to keep the CO2 equivalent (CO2e) emissions low. We used structural decomposition analysis to identify the drivers of change for CO2e emissions in these countries between 1995 and 2009, a period that includes the collapse of the Soviet Union, restructuring and economic growth and the great recession. The results show that final demand has been the main driving force for increasing emissions in the Baltic States and would have caused an 80%, 64% and 143% emission increase in Estonia, Latvia and Lithuania, respectively, all other factors kept con…
Household carbon footprints in the Baltic States: A global multi-regional input–output analysis from 1995 to 2011
2017
The paper analyzes consumption related household CO2 equivalent (CO2e) emissions for the three Baltic States – Estonia, Latvia and Lithuania from 1995 to 2011. The analysis is based on a multi-regional input–output model, which allows us to estimate life-cycle emissions for all major household consumption items. Results demonstrate that household carbon footprints in all the Baltic States significantly increased by 47% in Estonia, 20% in Latvia and 52% in Lithuania during the study period. In 2011 in Estonia expenditures for housing and utility contributed the highest per capita life-cycle emissions – 43%. However, in Lithuania housing accounted only for 16% of per capita emissions, but foo…
The role of the building sector for reducing energy consumption and greenhouse gases: An Italian case study
2013
The paper presents one of the first Italian experiences assessing the effectiveness of sustainable production and consumption strategies. The authors developed an energy and environmental extended input–output model, combined with the life cycle assessment, to analyse the role of the building sector in the reduction of Italian energy consumption and CO2 emissions. In detail, the model allows to assess the energy and environmental benefits arising from the Italian tax deduction policy for energy retrofit actions of buildings. Moreover, the authors defined an original model to assess the indirect rebound effect caused by the energy retrofit actions. The outcomes of the research point out that…
Application of the Structural Decomposition Analysis to assess the indirect energy consumption and air emission changes related to Italian households…
2012
Abstract The design of sustainable production and consumption strategies and the assessment of implemented actions require to identify the driving forces that influence the trend of energy consumption and environmental impacts. For this purpose, the Structural Decomposition Analysis (SDA) was developed as a suitable methodology to analyse the driving forces of the changes in economic, energy and environmental indicators. The paper presents one of the first Italian studies that apply an energy and environmental extended input–output model, opportunely shaped to the examined context, combined with SDA. In detail, it aims at: (1) investigating the energy use and the air emissions arisen from t…
The Stabilizing Role of Government Size
2007
This paper presents an analysis of how alternative models of the business cycle can replicate the stylized fact that large governments are associated with less volatile economies. Our analysis shows that adding nominal rigidities and costs of capital adjustment to an otherwise standard RBC model can generate a negative correlation between government size and the volatility of output. However, in the model, we find that the stabilizing effect is only due to a composition effect and it is not present when we look at the volatility of private output. Given that empirically we also observe a negative correlation between government size and the volatility of consumption, we modify the model by i…