The controller placement problem for wireless SDN

Wireless Networks - The software defined networking paradigm decouples the network’s control logic (the control plane) from the underlying routers and switches (the data plane), promoting...     

Single Domain 10 nm Ferromagnetism Imprinted on Superparamagnetic Nanoparticles Using Chiral Molecules

The rapid growth in demand for data and the emerging applications of Big Data require the increase of memory capacity. Magnetic memory devices are among the leading technologies for meeting this demand; however, they rely on the use of ferromagnets that creates size reduction limitations and poses complex materials requirements. Usually magnetic memory sizes are limited to 30–50 nm. Reducing the size even further, to the ≈10–20 nm scale, destabilizes the magnetization and its magnetic orientation becomes susceptible to thermal fluctuations and stray magnetic fields. In the present work, it is shown that 10 nm single domain ferromagnetism can be achieved. Using asymmetric adsorption of chiral molecules, superparamagnetic iron oxide nanoparticles become ferromagnetic with an average coercive field of ≈80 Oe. The asymmetric adsorption of molecules stabilizes the magnetization direction at room temperature and the orientation is found to depend on the handedness of the chiral molecules. These studies point to a novel method for the miniaturization of ferromagnets (down to ≈10 nm) using established synthetic protocols.     

A Black-Box Construction of Non-malleable Encryption from Semantically Secure Encryption

We show how to transform any semantically secure encryption scheme into a non-malleable one, with a black-box construction that achieves a quasi-linear blow-up in the size of the ciphertext. This improves upon the previous non-black-box construction of Pass, Shelat and Vaikuntanathan (Crypto ’06). Our construction also extends readily to guarantee non-malleability under a bounded-CCA2 attack, thereby simultaneously improving on both results in the work of Cramer et al. (Asiacrypt ’07). Our construction departs from the oft-used paradigm of re-encrypting the same message with different keys and then proving consistency of encryption. Instead, we encrypt an encoding of the message; the encoding is based on an error-correcting code with certain properties of reconstruction and secrecy from partial views, satisfied, e.g., by a Reed–Solomon code.     

Exploring the effects of driving experience on hazard awareness and risk perception via real-time hazard identification,hazard classification,and rating tasks

This study investigated the effects of driving experience on hazard awareness and risk perception skills. These topics have previously been investigated separately, yet a novel approach is suggested where hazard awareness and risk perception are examined concurrently. Young, newly qualified drivers, experienced drivers, and a group of commercial drivers, namely, taxi drivers performed three consecutive tasks: (1) observed 10 short movies of real-world driving situations and were asked to press a button each time they identified a hazardous situation; (2) observed one of three possible sub-sets of 8 movies (out of the 10 they have seen earlier) for the second time, and were asked to categorize them into an arbitrary number of clusters according to the similarity in their hazardous situation; and (3) observed the same sub-set for a third time and following each movie were asked to rate its level of hazardousness. The first task is considered a real-time identification task while the other two are performed using hindsight. During it participants’ eye movements were recorded. Results showed that taxi drivers were more sensitive to hidden hazards than the other driver groups and that young-novices were the least sensitive. Young-novice drivers also relied heavily on materialized hazards in their categorization structure. In addition, it emerged that risk perception was derived from two major components: the likelihood of a crash and the severity of its outcome. Yet, the outcome was rarely considered under time pressure (i.e., in real-time hazard identification tasks). Using hindsight, when drivers were provided with the opportunity to rate the movies’ hazardousness more freely (rating task) they considered both components. Otherwise, in the categorization task, they usually chose the severity of the crash outcome as their dominant criterion. Theoretical and practical implications are discussed.     

Publication attributes of leadership: what do they mean?

The article evaluates 48 approaches to leadership for the first time for the period of 1965–2016 using bibliometric methods. Our analysis combines four parameters: the number of publications, citations, self-citations, and dispersion of literature (a new parameter). The question of what is the most influential approach to leadership is addressed. We argue that the interplay among the four attributes observed in this study shows that transformational leadership is the most influential and popular approach to leadership in leadership studies today. However, there is a question of whether the excessive self-citations in this approach to leadership play a role in its augmented visibility.     

Antisemitism and Islamophobia: what does a bibliometric study reveal?

Although Islamophobia and Antisemitism are two phenomena different in their nature, both represent a form of Otherness that entails a complicated inclusion into multi-ethnic societies of modern Europe and the United States. The purpose of the present study is to show how the research literature has portrayed both phenomena in terms of bibliometric data retrieved from the SCIE Clarivate Analytics database. In addition, we were interested to find out if there is a literature that connects Islamophobia and Antisemitism, its direction and influence. Our findings show that because publications and citations on Islamophobia are relatively new, the research in terms of publications draws the attention of academic society in the direction of research of Antisemitism, but the citations count of the literature on Islamophobia exceeds by far that of the literature on Antisemitism. Moreover, we found that although Antisemitism and Islamophobia are distinct trends, there is an interaction between the literatures that discuss both, and the research that combines the analysis of both phenomena gains more influence than research dedicated to each phenomenon separately.     

Comparative advantage: the impact of ISO 14001 environmental certification on exports

Relative to the enormous acceptance of the ISO 9000 quality standard, the ISO 14001 environmental management certification has been met with only moderate enthusiasm among industrial facilities. The literature on corporate motivation for ISO 14001 participation is relatively modest considering the enormous number of publications reviewing other aspects of its adoption and implementation. It would seem that the present "marketing" package supporting ISO environmental commitments does not seem to offer sufficiently persuasive incentives for increased sales, either domestically or internationally. While researchers assume that a higher export rate of companies is positively associated with higher ISO participation rates, there have been very few empirical studies that support this inference, and conclusions have not been based on data taken from importing countries orfrom a systematic evaluation of expressed corporate preference for products sold by ISO 14001 certified companies. The present study reports the results of a survey to firms in six countries that are Israel's leading trade partners, importing chemicals, textiles, and produce. The survey results confirm that while the international market still considers price and quality as the paramount factors in selection of suppliers, environmental management systems (EMS) are an important feature that is frequently taken into consideration. EMS certification appears to signify a supplier who is managing the business well and exhibiting ethical responsibility. The European market proved to be more environmentally conscious than those in other industrialized parts of the world. EMS offer a particularly valuable advantage for producers wishing to reach European markets. As policy-makers seek to expand the voluntary adoption of EMS, a clear advantage for exporters should be highlighted among national industries.     

Simplified AIP‐II Peptidomimetics Are Potent Inhibitors of Staphylococcus aureus AgrC Quorum Sensing Receptors

The bacterial pathogen Staphylococcus aureus controls many aspects of virulence by using the accessory gene regulator (agr) quorum sensing (QS) system. The agr system is activated by a macrocyclic peptide signal known as an autoinducing peptide (AIP). We sought to develop structurally simplified mimetics of AIPs for use as chemical tools to study QS in S. aureus. Herein, we report new peptidomimetic AgrC receptor inhibitors based on a tail‐truncated AIP‐II peptide that have almost analogous inhibitory activities to the parent peptide. Structural comparison of one of these peptidomimetics to the parent peptide and a highly potent, all‐peptide‐derived, S. aureus agr inhibitor (AIP‐III D4A) revealed a conserved hydrophobic motif and overall amphipathic nature. Our results suggest that the AIP scaffold is amenable to structural mimicry and minimization for the development of synthetic agr inhibitors.     

Light Manipulation by Guanine Crystals in Organisms: Biogenic Scatterers,Mirrors, Multilayer Reflectors and Photonic Crystals

Guanine crystals are widely used in nature to manipulate light. The first part of this feature article explores how organisms are able to construct an extraordinary array of optical “devices” including diffuse scatterers, broadband and narrowband reflectors, tunable photonic crystals, and image‐forming mirrors by varying the size, morphology, and arrangement of guanine crystals. The second part presents an overview of some of the properties of crystalline guanine to explain why this material is ideally suited for such optical applications. The high reflectivity of many natural optical systems ultimately derives from the fact that guanine crystals have an extremely high refractive index—a product of its anisotropic crystal structure comprised of densely stacked H‐bonded layers. In order to optimize their reflectivity, many organisms exert exquisite control over the crystal morphology, forming plate‐like single crystals in which the high refractive index face is preferentially expressed. Guanine‐based optics are used in a wide range of biological functions such as in camouflage, display, and vision, and exhibit a degree of versatility, tunability, and complexity that is difficult to incorporate into artificial devices using conventional engineering approaches. These biological systems could inspire the next generation of advanced optical materials.