6,866 research outputs found

    A short note on the presence of spurious states in finite basis approximations

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    The genesis of spurious solutions in finite basis approximations to operators which possess a continuum and a point spectrum is discussed and a simple solution for identifying these solutions is suggested

    Implementation of a Multi-Criteria Decision Analysis (MCDA) Toolkit to Aid in Ranking Naval Mission Vessel Combinations With Uncertainty

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    United States (U.S.) military bases have largely been constructed outside of the contiguous United States (OCONUS) due to the need of close support logistics for conflicts and wars. In contrast, military bases within the contiguous United States (CONUS) have been constructed mostly due to economic and other related monetary factors. In addition to monetary concerns for the placement of military bases (specifically naval bases), there exists tactical, environmental, cultural, climate, logistical, and geographical issues that need to be fully considered before deciding on a naval installation location and the vessels to be stationed there. I will present a new toolkit to aid in the decision making process for placing naval vessels to maximize their strategic advantage—while reducing and managing risks—increasing the ability to protect and deter unforeseen threats and—if necessary—fight a future war while adhering to the Department of Defense’s (DoD) maritime strategy. The modification of a current integer linear program by introducing the Elimination Et Choix Traduisant la Realité (Electre) III MCDA model will be used to simulate a variety of naval fleet placement factors, weights, and decision maker (DM) preferences to aid in selection of mission scenarios

    Applying model-based systems engineering in search of quality by design

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    2022 Spring.Includes bibliographical references.Model-Based System Engineering (MBSE) and Model-Based Engineering (MBE) techniques have been successfully introduced into the design process of many different types of systems. The application of these techniques can be reflected in the modeling of requirements, functions, behavior, and many other aspects. The modeled design provides a digital representation of a system and the supporting development data architecture and functional requirements associated with that architecture through modeling system aspects. Various levels of the system and the corresponding data architecture fidelity can be represented within MBSE environment tools. Typically, the level of fidelity is driven by crucial systems engineering constraints such as cost, schedule, performance, and quality. Systems engineering uses many methods to develop system and data architecture to provide a representative system that meets costs within schedule with sufficient quality while maintaining the customer performance needs. The most complex and elusive constraints on systems engineering are defining system requirements focusing on quality, given a certain set of system level requirements, which is the likelihood that those requirements will be correctly and accurately found in the final system design. The focus of this research will investigate specifically the Department of Defense Architecture Framework (DoDAF) in use today to establish and then assess the relationship between the system, data architecture, and requirements in terms of Quality By Design (QbD). QbD was first coined in 1992, Quality by Design: The New Steps for Planning Quality into Goods and Services [1]. This research investigates and proposes a means to: contextualize high-level quality terms within the MBSE functional area, provide an outline for a conceptual but functional quality framework as it pertains to the MBSE DoDAF, provides tailored quality metrics with improved definitions, and then tests this improved quality framework by assessing two corresponding case studies analysis evaluations within the MBSE functional area to interrogate model architectures and assess quality of system design. Developed in the early 2000s, the Department of Defense Architecture Framework (DoDAF) is still in use today, and its system description methodologies continue to impact subsequent system description approaches [2]. Two case studies were analyzed to show proposed QbD evaluation to analyze DoDAF CONOP architecture quality. The first case study addresses the analysis of DoDAF CONOP of the National Aeronautics and Space Administration (NASA) Joint Polar Satellite System (JPSS) ground system for National Oceanic and Atmospheric Administration (NOAA) satellite system with particular focus on the Stored Mission Data (SMD) mission thread. The second case study addresses the analysis of DoDAF CONOP of the Search and Rescue (SAR) navel rescue operation network System of Systems (SoS) with particular focus on the Command and Control signaling mission thread. The case studies help to demonstrate a new DoDAF Quality Conceptual Framework (DQCF) as a means to investigate quality of DoDAF architecture in depth to include the application of DoDAF standard, the UML/SysML standards, requirement architecture instantiation, as well as modularity to understand architecture reusability and complexity. By providing a renewed focus on a quality-based systems engineering process when applying the DoDAF, improved trust in the system and data architecture of the completed models can be achieved. The results of the case study analyses reveal how a quality-focused systems engineering process can be used during development to provide a product design that better meets the customer's intent and ultimately provides the potential for the best quality product

    Agrarian structure in Poland : the myth of large-farm superiority

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    In Poland, present policies are aimed at promoting large, mechanized farms over smaller family farms. These policies are based on the perception that large farms offer real economies of scale. But international evidence indicates that such large, mechanized farms are generally less efficient and use less labor than small family farms. The authors analyzed the relationship between farm size and efficiency in Polish agriculture. They used two different methods to do so. First they determined differences in total factor productivity between small and large farms. They then used Data Envelope Analysis to estimate scale efficiencies. The results show that, for the sample of farms analyzed: 1) large farms are not more efficient than smaller farms; and 2) smaller farms are more labor-intensive than larger farms. These results have important policy implications for farm restructuring in Poland and other transition economies facing similar issues and conditions.Environmental Economics&Policies,Crops&Crop Management Systems,Agricultural Knowledge&Information Systems,Banks&Banking Reform,Economic Theory&Research,Banks&Banking Reform,Environmental Economics&Policies,Agricultural Knowledge&Information Systems,Crops&Crop Management Systems,Livestock&Animal Husbandry

    Improving the Convergence of an Iterative Algorithm Proposed By Waxman

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    In the iterative algorithm recently proposed by Waxman for solving eigenvalue problems, we point out that the convergence rate may be improved. For many non-singular symmetric potentials which vanish asymptotically, a simple analytical relationship between the coupling constant of the potential and the ground state eigenvalue is obtained which can be used to make the algorithm more efficient

    On the Absence of Spurious Eigenstates in an Iterative Algorithm Proposed By Waxman

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    We discuss a remarkable property of an iterative algorithm for eigenvalue problems recently advanced by Waxman that constitutes a clear advantage over other iterative procedures. In quantum mechanics, as well as in other fields, it is often necessary to deal with operators exhibiting both a continuum and a discrete spectrum. For this kind of operators, the problem of identifying spurious eigenpairs which appear in iterative algorithms like the Lanczos algorithm does not occur in the algorithm proposed by Waxman

    De-novo design of complementary (antisense) peptide mini-receptor inhibitor of interleukin 18 (IL-18).

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    Complementary (antisense) peptide mini-receptor inhibitors are complementary peptides designed to be receptor-surrogates that act by binding to selected surface features of biologically important proteins thereby inhibiting protein-cognate receptor interactions and subsequent biological effects. Previously, we described a complementary peptide mini-receptor inhibitor of interleukin-1beta (IL-1beta) that was designed to bind to an external surface loop (beta-bulge) of IL-1beta (Boraschi loop) clearly identified in the X-ray crystal structure of this cytokine. Here, we report the de-novo design and rational development of a complementary peptide mini-receptor inhibitor of cytokine interleukin-18 (IL-18), a protein for which there is no known X-ray crystal structure. Using sequence homology comparisons with IL-1beta, putative IL-18 surface loops are identified and used as a starting point for design, including a loop region 1 thought to be equivalent with the Boraschi loop of IL-1beta. Only loop region 1 complementary peptides are found to be promising leads as mini-receptor inhibitors of IL-18 but these are prevented from being properly successful owing to solubility problems. The application of "M-I pair mutagenesis" and inclusion of a C-terminal arginine residue are then sufficient to solve this problem and convert one lead peptide into a functional complementary peptide mini-receptor inhibitor of IL-18. This suggests that the biophysical and biological properties of complementary peptides can be improved in a rational and logical manner where appropriate, further strengthening the potential importance of complementary peptides as inhibitors of protein-protein interactions, even when X-ray crystal structural information is not readily available

    Health IT Security: An Examination of Modern Challenges in Maintaining HIPAA and HITECH Compliance

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    This work describes an undergraduate honors research project into some of the challenges modern healthcare providers face in maintaining compliance with the Health Insurance Portability and Accountability Act (HIPAA) and HITECH (Health Information Technology for Economic and Clinical Health) Act. An overview of the pertinent sections of both the HIPAA and HITECH Acts regarding health information security is provided, along with a discussion of traditionally weak points in information security, including: people susceptible to social engineering, software that is not or cannot be regularly updated, and targeted attacks (including advanced persistent threats, or APTs). Further, the paper examines potential violations of HIPAA involving vulnerabilities in commonly-used enterprise health records systems. Finally, we compare these challenges to the challenges of the United States healthcare system prior to 1995, specifically looking at information handling procedures, how procedures have changed, and how effective those changes have been
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