A Two-Phase Power Allocation Scheme for CRNs Employing NOMA

In this paper, we consider the power allocation (PA) problem in cognitive radio networks (CRNs) employing nonorthogonal multiple access (NOMA) technique. Specifically, we aim to maximize the number of admitted secondary users (SUs) and their throughput, without violating the interference tolerance threshold of the primary users (PUs). This problem is divided into a two-phase PA process: a) maximizing the number of admitted SUs; b) maximizing the minimum throughput among the admitted SUs. To address the first phase, we apply a sequential and iterative PA algorithm, which fully exploits the characteristics of the NOMA-based system. Following this, the second phase is shown to be quasiconvex and is optimally solved via the bisection method. Furthermore, we prove the existence of a unique solution for the second phase and propose another PA algorithm, which is also optimal and significantly reduces the complexity in contrast with the bisection method. Simulation results verify the effectiveness of the proposed two-phase PA scheme

Національномовна специфіка категоризації світу

У статті реалізовано системний підхід до вивчення національної специфіки мовної категоризації світу, який передбачає розгляд одиниць мови, передусім слова, у його зв’язку з реаліями життя народу, його історією, культурою, географічними умовами проживання, особливостями світосприйняття, менталітету, життєвим досвідом. З цією метою до аналізу семантики слів на позначення особи за місцем її проживання, крім дефініцій тлумачних словників української мови, залучено відомості з аспектних лінгвістичних словників (синонімів, антонімів) та спеціальних етнолінгвістичних і лінгвокультурологічних джерел. Окрему увагу приділено методам виявлення етноконотацій в ідеографічній параметризації української лексики.The article deals with the system approach to studying national language specificities that provides examination of a word in interrelation with life realities, history, culture, geographical conditions, features of world view, national mentality, life experience reflected in language. Such work demanded, except for the analysis of definitions of available explanatory dictionaries, attraction of data from aspect dictionaries (synonyms, antonyms) and special ethno linguistic and linguistic cultural source. The research has been carried on the basis of nouns-names of person according to the residence. The significant attention is given to the methods of research national language specificities of the world’s categorization

Capacity Comparison between MIMO-NOMA and MIMO-OMA with Multiple Users in a Cluster

In this paper, the performance of multiple-input multiple-output non-orthogonal multiple access (MIMO-NOMA) is investigated when multiple users are grouped into a cluster. The superiority of MIMO-NOMA over MIMO orthogonal multiple access (MIMO-OMA) in terms of both sum channel capacity and ergodic sum capacity is proved analytically. Furthermore, it is demonstrated that the more users are admitted to a cluster, the lower is the achieved sum rate, which illustrates the tradeoff between the sum rate and maximum number of admitted users. On this basis, a user admission scheme is proposed, which is optimal in terms of both sum rate and number of admitted users when the signal-to-interference-plus-noise ratio thresholds of the users are equal. When these thresholds are different, the proposed scheme still achieves good performance in balancing both criteria. Moreover, under certain conditions,it maximizes the number of admitted users. In addition, the complexity of the proposed scheme is linear to the number of users per cluster. Simulation results verify the superiority of MIMO-NOMA over MIMO-OMA in terms of both sum rate and user fairness, as well as the effectiveness of the proposed user admission scheme.Comment: accepted IEEE Journal on Selected Topics in Communications, June 2017, Keywords: Non-orthogonal multiple access (NOMA), multiple-input multiple-output (MIMO), channel capacity, sum rate, fairness, user admission, power allocatio

Cost development of low carbon energy technologies: Scenario-based cost trajectories to 2050, 2017 edition

Future costs of low carbon energy technologies differ widely depending on assumptions and methods used. This report addresses this gap by presenting internally consistent trajectories of capital investment costs to 2050 for selected low carbon energy technologies. In order to do so, it combines global scenario projections of technology deployment with the one-factor learning rate method. Global scenarios are used to identify a range, based on potential deployment, in line with baseline assumptions and two long-term decarbonisation pathways. A sensitivity analysis is performed based on different learning rates and results are compared with literature. It is found that, depending on the technology, a 15 % to 55 % reduction in capital investment costs of offshore wind turbines, photovoltaics, solar thermal electricity and ocean energy may be achieved by 2030 compared to 2015. From then onwards, cost reduction may slow down yet remains substantial especially for photovoltaics and ocean energy. However, the assumed deployment pathway (global scenario) and learning rate influences the cost trajectories and cost reduction potential of these technologies. For onshore wind turbines, geothermal energy, biomass CHPs and CCS technologies cost reduction is less pronounced and results between scenarios do not differ significantly. The main aspects that deserve further research are firstly, the decomposition of technology cost-components and the distinction between the parts in the cost-structure that learning applies from those that need to be estimated with different methods and secondly, the influence of raw material prices in future cost trajectories of low carbon energy technologies.JRC.C.7-Knowledge for the Energy Unio

Li-ion batteries for mobility and stationary storage applications

Li-ion battery costs could decrease rapidly, by at least 50 % in 2030 and up to 75 % in 2040, due to learning from mass production driven by electric vehicles. Stationary storage systems may benefit from somewhat slower yet substantial cost reduction of 65 %. Market barriers or inaction on climate goals can affect these trajectories.JRC.C.7 - Knowledge for the Energy Unio

Joint-Liability Debt and Fiscal Policies

This thesis uses quantitative and computational macroeconomic methods to analyze policies in the presence of financial and economic frictions. The thesis consists two chapters. In particular, the second chapter focuses on finding instruments that mitigate financial crises and stabilize sovereign bond yields, while the third chapter focuses on the optimal capital taxation under the presence of heterogeneity in risk aversion. In Chapter 2, I assess the consequences of implementing a joint liability debt system in a two-country small open economy model. With joint liability a default of one country makes the other participant liable for its debt. The results highlight a trade-off between the contagion risk, in the sense that this instrument may push some member states to default even though they are individually solvent, and cheaper access to credit on average, since lenders are at risk only if no participating sovereign is willing to service the debt. The findings suggest that the welfare consequences of this policy proposal hinge critically on the timing of its introduction: Introducing such instruments at the peak of the Eurozone crisis would have helped the Periphery and harm the Core member states, while its adoption during normal times has the potential to make all participants better-off. In Chapter 3, I introduce risk aversion heterogeneity based on empirical results, in an otherwise standard heterogeneous agents macroeconomic model with incomplete markets, in order to analyze the optimal level of taxation. The heterogeneity in risk aversion affects the precautionary motives on capital and therefore the optimal level of taxation. In the exercise I quantify the welfare implications that occur, because of different tax levels, during the transition period to the long-run equilibrium. The results predict that the optimal capital taxation is increasing when I introduce heterogeneity in risk aversion. This is happening for two reasons, (i) higher precautionary motives compare to the standard case produce higher welfare effects, (ii) agents with lower risk aversion are in favor of a higher capital taxation, since they accumulate less capital. | 80 page

Effects of Fertilization on Growth and Productivity of Three Milk Thistle Populations

Milk thistle is an important medicinal plant as it contains silymarin which has many pharmaceutical activities. The purpose of this study was to evaluate the influence of a stabilized nitrogen fertilizer alone or combined with a foliar fertilizer, containing phosphorous, potassium, iron, manganese, and zinc, on the plant development and fruit yield of three wild milk thistle populations originated from Greece. The fruits of the populations ‘Palaionterveno’, ‘Mesopotamia’, and ‘Spata’ were sown in plastic pots containing peat. Fertilization treatments were i) control - without application of fertilizer, ii) application of a stabilized nitrogen fertilizer, and iii) use of the stabilized fertilizer followed by applications of foliar fertilizer at three different growth stages. The results revealed that genetic material significantly affected the plant height, rosette diameter, and dry weight of root system. Moreover, the application of the nitrogen fertilizer alone or combined with a foliar fertilizer enhanced plant growth. Regarding the fruit yield, there was an interaction between the two factors

Towards net-zero emissions in the EU energy system by 2050

This report presents a comparison of 8 scenarios achieving more than 50% reduction of greenhouse gas emissions by 2030 compared to 1990, and 16 scenarios aiming at climate neutrality by 2050, similar with the ambitions of the “European Green Deal”. This report summarises insights into similar and diverging elements of the scenarios on how the EU energy system may change by 2030 and by 2050, compared to today. The wealth of information, stemming from how different organisations see the EU energy system to evolve within their own scenario context, can provide useful input to EU climate and energy strategies.JRC.C.7-Knowledge for the Energy Unio