Phase transitions related to the pigeonhole principle

Since Paris introduced them in the late seventies (Paris1978), densities turned out to be useful for studying independence results. Motivated by their simplicity and surprising strength we investigate the combinatorial complexity of two such densities which are strongly related to the pigeonhole principle. The aim is to miniaturise Ramsey's Theorem for $1$-tuples. The first principle uses an unlimited amount of colours, whereas the second has a fixed number of two colours. We show that these principles give rise to Ackermannian growth. After parameterising these statements with respect to a function f:N->N, we investigate for which functions f Ackermannian growth is still preserved

Key drivers of renewable energy deployment in the MENA Region: Empirical evidence using panel quantile regression

With the growing pressure from the adverse impact of environmental pollution and climate change, the deployment of renewable sources is becoming one of the economic priorities for governments worldwide. Despite potential gains of renewable sources, little evidence is provided in the literature about the determinants of renewable energy deployment in the MENA region. In particular, whether political stability, governance quality and financial development matter or not for unleashing the potentials of renewable energy programs. To this end, this paper aims to fill the gap by examining the impact of political stability, quality of governance and institutions, and financial development on the deployment of renewable energy production in 9 selected MENA countries using annual data over the period 1984-2014. Accordingly, an innovative panel quantile regression model with non-additive fixed effect has been developed to tackle this issue. Our findings confirm that the effect of political stability is clearly heterogeneous and supports earlier claims about the importance of political stability to foster investments in the renewable energy sector. Findings also show that financial development has a positive impact on renewable energy production. In addition, we also find that the interaction term between governance effectiveness and financial development is negative for the lower quantiles but positive for the highest quantiles. These findings support our hypotheses and suggest that political stability, governance effectiveness, and financial development are essential drivers for promoting renewable energy production in the MENA region

Measuring Recovery for Non-Contractual Investment

Parties who make investments that generate externalities may sometimes recover from the beneficiaries, even in the absence of contract. Previous scholarship has shown that granting recovery, based on either the cost of the investment or the benefit it confers, can provide optimal incentives to invest. However, this article demonstrates that the law often awards recovery that is neither purely cost-based, nor purely benefit-based, and instead equals either the greater-of or lesser-of the two measures. These hybrid approaches to recovery distort incentives to invest. The article demonstrates the prevalence of these practices, and explores informational and related reasons why they emerge. It argues that they generally are ill-suited to promote rational policies

Ancient technology and punctuated change: Detecting the emergence of the Edomite Kingdom in the Southern Levant.

While the punctuated equilibrium model has been employed in paleontological and archaeological research, it has rarely been applied for technological and social evolution in the Holocene. Using metallurgical technologies from the Wadi Arabah (Jordan/Israel) as a case study, we demonstrate a gradual technological development (13th-10th c. BCE) followed by a human agency-triggered punctuated "leap" (late-10th c. BCE) simultaneously across the entire region (an area of ~2000 km2). Here, we present an unparalleled, diachronic archaeometallurgical dataset focusing on elemental analysis of dozens of well-dated slag samples. Based on the results, we suggest punctuated equilibrium provides an innovative theoretical model for exploring ancient technological changes in relation to larger sociopolitical conditions-in the case at hand the emergence of biblical Edom-, exemplifying its potential for more general cross-cultural applications

Modeling and analysis of loaded multilayered magnetoelectroelastic structures composite materials: Applications

This paper presents the detailed analysis of fiber- reinforced magnetoelectroelastic composite plates. The work is divided into two major sections. The first one deals with the homogenization of the properties of each layer based on the Mori-Tanaka mean field approach where all the needed effective coefficients of each layer are determined. Then, in order to perform analysis of the considered, the Stroh formalism is used to provide solutions for multifunctional multilayered magnetoelectroelastic composites, to predict exactly the mechanical and electrical behaviors near or across the interface of material layers

Solution of a statistical mechanics model for pulse formation in lasers

We present a rigorous statistical-mechanics theory of nonlinear many mode laser systems. An important example is the passively mode-locked laser that promotes pulse operation when a saturable absorber is placed in the cavity. It was shown by Gordon and Fischer [1] that pulse formation is a first-order phase transition of spontaneous ordering of modes in an effective "thermodynamic" system, in which intracavity noise level is the effective temperature. In this paper we present a rigorous solution of a model of passive mode locking. We show that the thermodynamics depends on a single parameter, and calculate exactly the mode-locking point. We find the phase diagram and calculate statistical quantities, including the dependence of the intracavity power on the gain saturation function, and finite size corrections near the transition point. We show that the thermodynamics is independent of the gain saturation mechanism and that it is correctly reproduced by a mean field calculation. The outcome is a new solvable statistical mechanics system with an unstable self-interaction accompanied by a natural global power constraint, and an exact description of an important many mode laser system.Comment: 10 pages, 3 figures, RevTe

Nonparty Interests in Contract Law

Contract law has one overarching goal: to advance the legitimate interests of the contracting parties. For the most part, scholars, judges, and parties embrace this party primacy norm, recognizing only a few exceptions, such as mandatory rules that bar enforcement of agreements that harm others. This Article describes a distinct species of previously unnoticed contract law rules that advance nonparty interests, which it calls “nonparty defaults. In doing so, this Article makes three contributions to the contract law literature. First, it identifies nonparty defaults as a judicial technique. It shows how courts deviate from the party primary norm with surprising frequency through a variety of default rules, interpretation practices, and remedies. These defaults are meant to protect nonparties’ interests and benefit society at large. Second, it develops a normative account as to when common law courts adjudicating contract disputes are a suitable forum to identify and advance nonparty interests. Finally, it documents and explains the surprising durability of nonparty defaults, which the parties could, but rarely do, disclaim

Eye movements when looking at potential friends and romantic partners

Eye movements of 105 heterosexual undergraduate students (36 males) were monitored while viewing photographs of men and women identified as a potential mate or a potential friend. Results showed that people looked at the head and chest more when assessing potential mates and looked at the legs and feet more when assessing potential friends. Single people looked at the photographs longer and more frequently than coupled people, especially when evaluating potential mates. In addition, eye gaze was a valid indicator of relationship interest. For women, looking at the head corresponded to greater interest in friendship, whereas for men looking at the head corresponded to less interest in friendship. These findings show that relational goals and gender may affect the way people scan their environment and search for relevant information in line with their goals

A Cooperative and Hybrid Network Intrusion Detection Framework in Cloud Computing Based on Snort and Optimized Back Propagation Neural Network

AbstractCloud computing provides a framework for supporting end users easily attaching powerful services and applications through Internet. To give secure and reliable services in cloud computing environment is an important issue. Providing security requires more than user authentication with passwords or digital certificates and confidentiality in data transmission, because it is vulnerable and prone to network intrusions that affect confidentiality, availability and integrity of Cloud resources and offered services. To detect DoS attack and other network level malicious activities in Cloud, use of only traditional firewall is not an efficient solution. In this paper, we propose a cooperative and hybrid network intrusion detection system (CH-NIDS) to detect network attacks in the Cloud environment by monitoring network traffic, while maintaining performance and service quality. In our NIDS framework, we use Snort as a signature based detection to detect known attacks, while for detecting network anomaly, we use Back-Propagation Neural network (BPN). By applying snort prior to the BPN classifier, BPN has to detect only unknown attacks. So, detection time is reduced. To solve the problem of slow convergence of BPN and being easy to fall into local optimum, we propose to optimize the parameters of it by using an optimization algorithm in order to ensure high detection rate, high accuracy, low false positives and low false negatives with affordable computational cost. In addition, in this framework, the IDSs operate in cooperative way to oppose the DoS and DDoS attacks by sharing alerts stored in central log. In this way, unknown attacks that were detected by any IDS can easily be detected by others IDSs. This also helps to reduce computational cost for detecting intrusions at others IDS, and improve detection rate in overall the Cloud environment