S-Duality for D3-Brane in NS-NS and R-R Backgrounds

We construct the low-energy effective field theory for a D3-brane in constant R-R 2-form potential background as the S-dual theory of a D3-brane in NS-NS B-field background. Despite the non-Abelian algebra of the noncommutative U(1) gauge symmetry, the electromagnetic duality transformation can be carried out to all orders, and the dual Lagrangian is given in a compact form. The gauge algebra is found to be a mixture of a deformed area-preserving diffeomorphism and the usual U(1) gauge symmetry.Comment: 29 pages, minor change

Introduction – Exploring and Expanding the Political World Pioneered by Don T. Nakanishi

This essay provides an introduction to the late Don T. Nakanishi of UCLA, commenting on his legacy in the founding and development of Asian American politics as a field. It also offers an overview of the articles and dialogue essays included in this special PGI issue on Asian Pacific American Politics, the first of its kind in the nation

Debris flow susceptibility mapping in Colorado Front Range, USA: A comparison of physics-based and data-driven approaches

This study used an inventory of debris flow triggered by a storm event in Colorado Front Range as an example to compare the capability of data-driven and physics-based approaches for regional-scale debris flow susceptibility mapping (LSM). Nine debris flow contributing factors were collected for the present study based on the availability of geophysical data in the study area. These contributing factors represent hillslope geometries, surface hydrology, and soil conditions. For the physics-based approach, the infinite slope model was used to directly determine the debris flow susceptibility for the study area by calculating the factor of safety (FS) based on parameters derived from geophysical data. For the data-driven approach, an artificial neural network (ANN) was developed to predict debris flow susceptibility for the study area by learning relationships from the contributing factors using the debris flow inventory. The results showed that both physics-based and data-driven models predicted debris flow susceptibility in the study area with relatively high accuracy; the data-driven approach outperformed the physics-based approach as it could extract complex features which the physics-based approach did not consider

Environmental and Energy Assessment of Biomass Residues to Biochar as Fuel: A Brief Review with Recommendations for Future Bioenergy Systems

This study explores the environmental and energy benefits of biomass residues, including crop residues and agricultural waste, for the production of renewable energy in the form of biochar as fuel, in order to offer recommendations for policy makers, by reviewing information regarding the key environmental issues associated with the implementation of the systems. The highest environmental benefits for biochar-to-fuel systems were most observed in reduction of global warming potentials (i.e., carbon abatement), particularly for those integrated with combined heat and power technology, or for those incorporating electricity offsets from biochar combustion and co-firing. But all of these practices come at the cost of hidden environmental burdens, such as elevations in eutrophication, acidification, carcinogens and ecotoxicity impacts, as a consequence from land use change, additional infrastructure requirement or additional fertilizer application connected to biochar production or post-treatment. Other notable challenges, including regional availability of biomass residues, improper management of the residues, limited economic incentives, low energy efficiency and synergies, as well as mistreating adverse impacts from indirect land use change, were discussed. This suggests the flexibility to adjust the biomass-biochar ratio to optimize desired energy yields, carbon abatement and environmental beneficial objectives. Comprehensive analysis of the trade-offs between energy yields, carbon abatement and other associated environmental impacts is therefore recommended for future studies. Future studies in this field are also advised to explore the solution and to develop methodologies capable of quantifying the impacts and other equally relevant trade-offs, to better reflect the changes in real-world trends for decision making

Stationary Light Pulses in Cold Atomic Media

Stationary light pulses (SLPs), i.e., light pulses without motion, are formed via the retrieval of stored probe pulses with two counter-propagating coupling fields. We show that there exist non-negligible hybrid Raman excitations in media of cold atoms that prohibit the SLP formation. We experimentally demonstrate a method to suppress these Raman excitations and realize SLPs in laser-cooled atoms. Our work opens the way to SLP studies in cold as well as in stationary atoms and provides a new avenue to low-light-level nonlinear optics.Comment: 4 pages, 4 figure

Integration of Social Media News Mining and Text Mining Techniques to Determine a Corporate’s Competitive Edge

Market globalization have triggered much more severe challenges for corporates than ever before. Thus, how to survive in this highly fluctuating economic atmosphere is an attractive topic for corporate managers, especially when an economy goes into a severe recession. One of the most consensus conclusions is to highly integrate a corporate’s supply chain network, as it can facilitate knowledge circulation, reduce transportation cost, increase market share, and sustain customer loyalty. However, a corporate’s supply chain relations are unapparent and opaque. To solve such an obstacle, this study integrates text mining (TM) and social network analysis (SNA) techniques to exploit the latent relation among corporates from social media news. Sequentially, this study examines its impact on corporate operating performance forecasting. The empirical result shows that the proposed mechanism is a promising alternative for performance forecasting. Public authorities and decision makers can thus consider the potential implications when forming a future policy

The Voting Rights Act and the Election of Nonwhite Officials

Voting Rights Act (VRA) is one of the most important—if not the most important—public policies developed over the last half century to increase access to the U.S. political system for people of color. The VRA also provides an important context for understanding the ascension of nonwhite groups into the elected leadership of the nation (Browning, Marshall, and Tabb 1984; Davidson and Grofman 1994; Menifield 2001; Mc-Clain and Stewart 2002; Segura and Bowler 2005; Bositis 2006). This essay assesses the present-day significance of the VRA for the political representation of communities of color by examining the implications of majority-minority districts and other key provisions in the VRA for the election of nonwhite officials in the beginning years of the twenty-first century

Delayed Airway Obstruction after Internal Jugular Venous Catheterization in a Patient with Anticoagulant Therapy

Delayed onset of neck hematoma following central venous catheterization without arterial puncture is uncommon. Herein, we present a patient who developed a delayed neck hematoma after repeated attempts at right internal jugular venous puncture and subsequent enoxaparin administration. Progressive airway obstruction occurred on the third day after surgery. Ultrasound examination revealed diffuse hematoma of the right neck, and fibreoptic examination of the airway revealed pharyngeal edema. After emergent surgical removal of the hematoma, the patient was extubated uneventfully

Planning and Implantation of NetFPGA Platform on Network Emulation Testbed

The concepts of cloud computing and Internet applications have expanded gradually and have become more and more important. Researchers need a new, high-speed network to build experimental environments for testing new network protocolswithout affecting existing traffic. In this paper, we describe a way to integrate NetFPGA platform, OpenFlow concept and NetFPGA reference designs into anetwork testbed to improve the packet processing speed and the dynamic adjustability for network emulation experiments. Furthermore, combined with Tunneling and VPLS, the proposed network testbed can be connected to distributed network, thus providing researchers a traffic-controllable and NIC-programmable experimental networking testbed in intra-communicating part