Spectral Efficient and Energy Aware Clustering in Cellular Networks

The current and envisaged increase of cellular traffic poses new challenges to Mobile Network Operators (MNO), who must densify their Radio Access Networks (RAN) while maintaining low Capital Expenditure and Operational Expenditure to ensure long-term sustainability. In this context, this paper analyses optimal clustering solutions based on Device-to-Device (D2D) communications to mitigate partially or completely the need for MNOs to carry out extremely dense RAN deployments. Specifically, a low complexity algorithm that enables the creation of spectral efficient clusters among users from different cells, denoted as enhanced Clustering Optimization for Resources' Efficiency (eCORE) is presented. Due to the imbalance between uplink and downlink traffic, a complementary algorithm, known as Clustering algorithm for Load Balancing (CaLB), is also proposed to create non-spectral efficient clusters when they result in a capacity increase. Finally, in order to alleviate the energy overconsumption suffered by cluster heads, the Clustering Energy Efficient algorithm (CEEa) is also designed to manage the trade-off between the capacity enhancement and the early battery drain of some users. Results show that the proposed algorithms increase the network capacity and outperform existing solutions, while, at the same time, CEEa is able to handle the cluster heads energy overconsumption

The Effects of Terrorism and War on the Oil and Prices Stock Indices Relationship

This paper, investigates the effect war and terrorism, have on the covariance between oil prices and the indices of four major stock markets - the American S&P500 and the European DAX, CAC40 and FTSE100 - using nonlinear BEKK-GARCH type models. Findings reported herein indicate that the covariance between stock and oil returns is affected by war. A tentative explanation is that the two wars examined here, predispose investors and market agents for more profound and longer lasting effects. On the other hand, in the case of terrorist incidents that, vis-à-vis war, are of a more transitory nature and one-off security shocks, only the co-movement between CAC40, DAX and oil returns is affected. No significant impact for the same terrorist events is observed in the relationship between the S&P500, FTSE100 and oil returns. This difference in the reaction may tentatively be interpreted as indicating that the latter markets are more efficient in absorbing the impact of terrorist attacks.war, terrorism, crude oil, stock market returns, co-movement

Rogue State Behavior and Markets: The Financial Fallout of North Korean Nuclear Tests

Financial markets react to major political events. The two nuclear tests conducted by North Korea in 2006 and 2009 were a sober confirmation of the nuclear weapon capacity of this state with the concomitant potential security threat this posed for the stability of the greater region. We examine how ten regional stock exchanges and currency markets reacted to this security development and these two specific events. The results, although not uniform across all countries and markets, revealed a greater adverse effect in the case of the second of the two tests. On the whole, the adverse effects on the stock exchanges were short lived

Terrorism and Political Self-Placement in European Union Countries

Terrorism is widely regarded as a public bad vis-\ue0-vis security - a public good - affecting the subjective well-being of citizens. As studies have shown, citizens' risk-perceptions and risk-assessment are affected by large scale terrorist acts. Reported evidence shows that individuals are often willing to trade-off civil liberties for enhanced security particularly as a post-terrorist attack reaction as well as adopting more conservative views. Within this strand of the literature, this paper examines whether terrorism and in particular mass-casualty terrorist attacks affect citizens' political selfplacement on the left-right scale of the political spectrum. To this effect the Eurobarometer Surveys for twelve European Union countries are utilised and Ordered Probit models are employed for the period 1985-2010 with over 230 thousand observations used in the estimations. On balance, the findings reported herein seem to be pointing to a shift in respondents' self-positioning towards the right of the political spectrum

Terrorism and Market Jitters

Terrorist actions can have a multitude of economic consequences that may adversely affect a number of economic indices, sectors and activities including growth and investment. From the markets' perspective, terrorist attacks are unforeseen events that, depending among other things on their magnitude, the number of casualties, the extent of the damages, the targets hit; shake and rattle them. Such incidents can also have a high contagion potential with the shock waves travelling quickly from onemarket to another. Nevertheless, the negative impact on markets from terrorist attacks is, in comparative terms, mild and short-lived

Has Stock Markets' Reaction to Terrorist Attacks Changed throughout Time?: Comparative Evidence from a Large and a Small Capitalisation Market

An expanding body of literature has addressed the question of the economic impact terrorist attacks have. A part of this literature has focused on the impact recent major terrorist hits had on financial markets. The question addressed by this paper is to what extent markets' reaction to major terrorist hits has changed over time. A large - the London stock exchange - and a small - the Athens stock exchange - capitalization market are used as the vehicles for the empirical investigation. Results from event study methodology as well as from conditional volatility models used here do no seem to point to any clear and unequivocal picture. Both markets appear to react selectively to terrorist events with no evidence of a noticeable change through time. Generally the effects appear to be transitory in both markets and seem to depend on the political and symbolic significance of the target hit. Market size and maturity also seem to influence the degree of the effects.terrorism, financial markets, volatility, event study

Hygrothermal evaluation of a museum storage building based on actual measurements and simulations

AbstractMuseum storage buildings should be able to provide a considerable stable indoor environment in terms of temperature and relative humidity (RH). To obtain such stable conditions with the lowest possible energy consumption, passive air conditioning is one-way solution. In this paper, indoor environment facilities of a passive museum storage building in Vejle region in Denmark, are investigated. Results demonstrate that the weather conditions of the previous yearś considerably affect the indoor environment of the storage. What is more, concentrated dehumidification is a sufficient technique to maintain RH within acceptable levels. Therefore, renewable energy such us excess wind energy during the night can be utilized

Terrorism Induced Cross-Market Transmission of Shocks: A Case Study Using Intraday Data

Terrorist incidents exert a negative, albeit generally short-lived, impact on markets and equity returns. Given the integration of global financial markets, mega-terrorist events also have a high contagion potential with their shock waves being transmitted across countries and markets. This paper investigates the cross-market transmission of the London Stock Exchange's reaction to the terrorist attacks of 2005. It focuses on how this reaction was transmitted to two other major European stock exchanges: Frankfurt and Paris. To this effect, high frequency data are used and multivariate GARCH models are employed. Findings reported herein indicate that the volatility of stock market returns is increased in all three cases

The Effects of Terrorism and War on the Oil and Prices Stock Indices Relationship

This paper, investigates the effect war and terrorism, have on the covariance between oil prices and the indices of four major stock markets - the American S&P500 and the European DAX, CAC40 and FTSE100 - using nonlinear BEKK-GARCH type models. Findings reported herein indicate that the covariance between stock and oil returns is affected by war. A tentative explanation is that the two wars examined here, predispose investors and market agents for more profound and longer lasting effects. On the other hand, in the case of terrorist incidents that, vis-\ue0-vis war, are of a more transitory nature and one-off security shocks, only the co-movement between CAC40, DAX and oil returns is affected. No significant impact for the same terrorist events is observed in the relationship between the S&P500, FTSE100 and oil returns. This difference in the reaction may tentatively be interpreted as indicating that the latter markets are more efficient in absorbing the impact of terrorist attacks