50,140 research outputs found

    Quantifying Eulerian Eddy Leakiness in an Idealized Model

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    An idealized eddy‐resolving ocean basin, closely resembling the North Pacific Ocean, is simulated using MITgcm. We identify rotationally coherent Lagrangian vortices (RCLVs) and sea surface height (SSH) eddies based on the Lagrangian and Eulerian framework, respectively. General statistical results show that RCLVs have a much smaller coherent core than SSH eddies with the ratio of radius is about 0.5. RCLVs are often enclosed by SSH anomaly contours, but SSH eddy identification method fails to detect more than half of RCLVs. Based on their locations, two types of eddies are classified into three categories: overlapping RCLVs and SSH eddies, nonoverlapping SSH eddies, and nonoverlapping RCLVs. Using Lagrangian particles, we examine the processes of leakage and intrusion around SSH eddies. For overlapping SSH eddies, over the lifetime, the material coherent core only accounts for about 25% and about 50% of initial water leak from eddy interior. The remaining 25% of water can still remain inside the boundary, but only in the form of filaments outside the coherent core. For nonoverlapping SSH eddies, more water leakage (about 60%) occurs at a faster rate. Guided by the number and radius of SSH eddies, fixed circles and moving circles are randomly selected to diagnose the material flux around these circles. We find that the leakage and intrusion trends of moving circles are quite similar to that of nonoverlapping SSH eddies, suggesting that the material coherence properties of nonoverlapping SSH eddies are not significantly different from random pieces of ocean with the same size

    Data analytics for modeling and visualizing attack behaviors: A case study on SSH brute force attacks

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    In this research, we explore a data analytics based approach for modeling and visualizing attack behaviors. To this end, we employ Self-Organizing Map and Association Rule Mining algorithms to analyze and interpret the behaviors of SSH brute force attacks and SSH normal traffic as a case study. The experimental results based on four different data sets show that the patterns extracted and interpreted from the SSH brute force attack data sets are similar to each other but significantly different from those extracted from the SSH normal traffic data sets. The analysis of the attack traffic provides insight into behavior modeling for brute force SSH attacks. Furthermore, this sheds light into how data analytics could help in modeling and visualizing attack behaviors in general in terms of data acquisition and feature extraction

    Peierls distorted chain as a quantum data bus for quantum state transfer

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    We systematically study the transfer of quantum state of electron spin as the flying qubit along a half-filled Peierls distorted tight-binding chain described by the Su-Schrieffer-Heeger (SSH) model, which behaves as a quantum data bus. This enables a novel physical mechanism for quantum communication with always-on interaction: the effective hopping of the spin carrier between sites AA and BB connected to two sites in this SSH chain can be induced by the quasi-excitations of the SSH model. As we prove, it is the Peierls energy gap of the SSH quasi-excitations that plays a crucial role to protect the robustness of the quantum state transfer process. Moreover, our observation also indicates that such a scheme can also be employed to explore the intrinsic property of the quantum system.Comment: 10 pages, 6 figure

    Ph.D. graduates in the humanities and social sciences: what do they do?

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    In recent years, more and more doctorate holders in Belgium and other OECD countries are employed in jobs outside academia. Particularly little is known about careers of graduates in the social sciences and the humanities (SSH). Therefore, this paper addresses several aspects of their careers. Based on the Belgian CDH data 2010, 919 doctorate holders were surveyed. We found that academia is the largest sector of employment for doctorate holders in humanities and social sciences but there is variation among cohorts and various subdisciplines within SSH. Only for a minority of the doctorate holders working outside higher education, a doctoral degree is required. Compared to other fields of study, doctorate holders in SSH experienced a difficult transition from academia to other sectors of employment. Despite these findings, Ph.D. holders in SSH feel their research experience is an asset for their current job. Future research needs to explore how the training of Ph.D. students can facilitate the transition to the non-academic labour market

    Some thoughts on the importance of open source and open access for emerging digital scholarship

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    Both the open source and the open access movements have their roots in the ‘hard’ sciences rather than in the social Sciences and Humanities (SSH). They have been concerned, traditionally, with open access to source code for computational data processing and with open access to scienti?c information published as journal articles. Still, the basic assumption of the present contribution is that there is a specific open source and open access agenda within the SSH and that this may affect these disciplines—once such an agenda is fully in place — in a way hardly conceivable in the ‘hard’ sciences. However, understanding the full impact and potential of such approaches in the SSH requires reflection upon broader methodological issues. Two vectors or primary oppositions are of specific interest in this respect: the scholarly information continuum as a whole and its evolution from print based to electronic working paradigms and the revolutionary changes that can be foreseen as a consequence the speci?c difference of the SSH as opposed to the Science-TechnologyMedicine (STM) culture of relating signi?ers to signi?cates and the specific impact of the digital revolution resulting from this specific difference. Exploring these two vectors this contribution will try to indicate constituent elements of an ‘open’ agenda for the digital humanities
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