Characterizing killing vector fields of standard static space-times

Cataloged from PDF version of article.We provide a global characterization of the Killing vector fields of a standard static space-time by a system of partial differential equations. By studying this system, we determine all the Killing vector fields in the same framework when the Riemannian part is compact. Furthermore, we deal with the characterization of Killing vector fields with zero curl on a standard static space-time. © 2011 Elsevier B.V.

Weight optimization of an aerobrake structural concept for a lunar transfer vehicle

An aerobrake structural concept for a lunar transfer vehicle was weight optimized through the use of the Taguchi design method, finite element analyses, and element sizing routines. Six design parameters were chosen to represent the aerobrake structural configuration. The design parameters included honeycomb core thickness, diameter-depth ratio, shape, material, number of concentric ring frames, and number of radial frames. Each parameter was assigned three levels. The aerobrake structural configuration with the minimum weight was 44 percent less than the average weight of all the remaining satisfactory experimental configurations. In addition, the results of this study have served to bolster the advocacy of the Taguchi method for aerospace vehicle design. Both reduced analysis time and an optimized design demonstrated the applicability of the Taguchi method to aerospace vehicle design

Quantum Hall Effect on the Grassmannians Gr2(CN)\mathbf{Gr}_2(\mathbb{C}^N)

Quantum Hall Effects (QHEs) on the complex Grassmann manifolds $\mathbf{Gr}_2(\mathbb{C}^N)$ are formulated. We set up the Landau problem in $\mathbf{Gr}_2(\mathbb{C}^N)$ and solve it using group theoretical techniques and provide the energy spectrum and the eigenstates in terms of the $SU(N)$ Wigner ${\cal D}$-functions for charged particles on $\mathbf{Gr}_2(\mathbb{C}^N)$ under the influence of abelian and non-abelian background magnetic monopoles or a combination of these thereof. In particular, for the simplest case of $\mathbf{Gr}_2(\mathbb{C}^4)$ we explicitly write down the $U(1)$ background gauge field as well as the single and many-particle eigenstates by introducing the Pl\"{u}cker coordinates and show by calculating the two-point correlation function that the Lowest Landau Level (LLL) at filling factor $\nu =1$ forms an incompressible fluid. Our results are in agreement with the previous results in the literature for QHE on ${\mathbb C}P^N$ and generalize them to all $\mathbf{Gr}_2(\mathbb{C}^N)$ in a suitable manner. Finally, we heuristically identify a relation between the $U(1)$ Hall effect on $\mathbf{Gr}_2(\mathbb{C}^4)$ and the Hall effect on the odd sphere $S^5$, which is yet to be investigated in detail, by appealing to the already known analogous relations between the Hall effects on ${\mathbb C}P^3$ and ${\mathbb C}P^7$ and those on the spheres $S^4$ and $S^8$, respectively.Comment: 34 pages, revtex 4-1, Minor Correction

A complex structure representation of the US critical infrastructure protection program based on the Zachman Framework

Critical infrastructures are vital assets for public safety, economic welfare or national security of countries. The importance of critical infrastructures necessitates state-level coordination of security efforts based on some rigid policies, strategies, and procedures. This hierarchical set of rules is collectively referred to as the critical infrastructure protection program (CIPP). As the pioneer of CIPP, the USA has a very complex program in which partners and stakeholders have multiple and varied interacting roles and responsibilities. The complexity of roles and interactions creates a need to make a representation of these complex structures by using intuitive tools. The Zachman framework is such a tool that provides a formal and structured way of viewing and defining a complex enterprise. It is represented by a 6×6 matrix with rows defining stakeholders and columns defining underlying interrogatives. In this article, a proof-of-concept study is performed to represent the US CIPP using the Zachman framework. The proof-of-concept study showed that the Zachman framework could be beneficial in overcoming challenges of a CIPP program which can be regarded as a complex enterprise

Use of evidence to support healthy public policy: a policy effectiveness-feasibility loop

Public policy plays a key role in improving population health and in the control of diseases, including non-communicable diseases. However, an evidence-based approach to formulating healthy public policy has been difficult to implement, partly on account of barriers that hinder integrated work between researchers and policy-makers. This paper describes a “policy effectiveness–feasibility loop” (PEFL) that brings together epidemiological modelling, local situation analysis and option appraisal to foster collaboration between researchers and policy-makers. Epidemiological modelling explores the determinants of trends in disease and the potential health benefits of modifying them. Situation analysis investigates the current conceptualization of policy, the level of policy awareness and commitment among key stakeholders, and what actually happens in practice, thereby helping to identify policy gaps. Option appraisal integrates epidemiological modelling and situation analysis to investigate the feasibility, costs and likely health benefits of various policy options. The authors illustrate how PEFL was used in a project to inform public policy for the prevention of cardiovascular diseases and diabetes in four parts of the eastern Mediterranean. They conclude that PEFL may offer a useful framework for researchers and policy-makers to successfully work together to generate evidence-based policy, and they encourage further evaluation of this approach

Exploring Blockchain Adoption Supply Chains: Opportunities and Challenges

Acquisition Management / Grant technical reportAcquisition Research Program Sponsored Report SeriesSponsored Acquisition Research & Technical ReportsIn modern supply chains, acquisition often occurs with the involvement of a network of organizations. The resilience, efficiency, and effectiveness of supply networks are crucial for the viability of acquisition. Disruptions in the supply chain require adequate communication infrastructure to ensure resilience. However, supply networks do not have a shared information technology infrastructure that ensures effective communication. Therefore decision-makers seek new methodologies for supply chain management resilience. Blockchain technology offers new decentralization and service delegation methods that can transform supply chains and result in a more flexible, efficient, and effective supply chain. This report presents a framework for the application of Blockchain technology in supply chain management to improve resilience. In the first part of this study, we discuss the limitations and challenges of the supply chain system that can be addressed by integrating Blockchain technology. In the second part, the report provides a comprehensive Blockchain-based supply chain network management framework. The application of the proposed framework is demonstrated using modeling and simulation. The differences in the simulation scenarios can provide guidance for decision-makers who consider using the developed framework during the acquisition process.Approved for public release; distribution is unlimited

Cyber Third-Party Risk Management: A Comparison of Non-Intrusive Risk Scoring Reports

Cybersecurity is a concern for organizations in this era. However, strengthening the security of an organization’s internal network may not be sufficient since modern organizations depend on third parties, and these dependencies may open new attack paths to cybercriminals. Cyber Third-Party Risk Management (C-TPRM) is a relatively new concept in the business world. All vendors or partners possess a potential security vulnerability and threat. Even if an organization has the best cybersecurity practice, its data, customers, and reputation may be at risk because of a third party. Organizations seek effective and efficient methods to assess their partners’ cybersecurity risks. In addition to intrusive methods to assess an organization’s cybersecurity risks, such as penetration testing, non-intrusive methods are emerging to conduct C-TPRM more easily by synthesizing the publicly available information without requiring any involvement of the subject organization. In this study, the existing methods for C-TPRM built by different companies are presented and compared to discover the commonly used indicators and criteria for the assessments. Additionally, the results of different methods assessing the cybersecurity risks of a specific organization were compared to examine reliability and consistency. The results showed that even if there is a similarity among the results, the provided security scores do not entirely converge

Microfluidic production of perfluorocarbon-alginate core-shell microparticles for ultrasound therapeutic applications

The fabrication of micrometer-sized core−shell particles for ultrasound-triggered delivery offers a variety of applications in medical research. In this work, we report the design and development of a glass capillary microfluidic system containing three concentric glass capillary tubes for the development of core−shell particles. The setup enables the preparation of perfluorocarbon-alginate core−shell microspheres in a single process, avoiding the requirement for further extensive purification steps. Core−shell microspheres in the range of 110−130 μm are prepared and are demonstrated to be stable up to 21 days upon immersion in calcium chloride solution or water. The mechanical stability of the particles is tested by injecting them through a 23 gauge needle into a polyacrylamide gel to mimic the tissue matrix. The integrity of the particles is maintained after the injection process and is disrupted after ultrasound exposure for 15 min. The results suggest that the perfluorcarbon-alginate microparticles could be a promising system for the delivery of compounds, such as proteins, peptides, and small-molecule drugs in ultrasound-based therapies.The authors acknowledge Gulden Camci-Unal for her help with the confocal microscope analysis. A.R.C.D. acknowledges the Fulbright Commission for the visiting scholar granted. We also acknowledge the financial support from project "Novel smart and biomimetic materials for innovative regenerative medicine approaches (RL1 - ABMR - NORTE-01-0124-FEDER-000016)" cofinanced by the North Portugal Regional Operational Programme (ON.2 - O Novo Norte) under the National Strategic Reference Framework (NSRF) through the European Regional Development Fund (ERDF) and FEDER

Perforated Hepatic Hydatid Cyst into the Peritoneum with Mild Symptoms

Rupture into the abdominal cavity is a rare but serious complication of hydatid disease that necessitates emergency surgical intervention. We present herein a case with mild abdominal symptoms due to hydatid cyst rupture into the peritoneum after trauma. A 24-year-old man was admitted to the emergency room with mild abdominal pain. His symptoms had started after a fall four days earlier. Ultrasonography and computed tomography showed cystic lesions in the liver and peritoneum with intraabdominal free fluid. He was treated surgically with partial cystectomy and falciformoplasty. Postoperative albendazole therapy was given for two months. There was not recurrence four months postoperatively at control computed tomography