A corrosion monitoring system for existing reinforced concrete structures.
DOT National Transportation Integrated Search
2015-05-01
This study evaluated a multi-parameter corrosion monitoring system for existing reinforced concrete structures in chloride-laden service environments. The system was fabricated based on a prototype concrete corrosion measurement system that : had bee...
Siskind, Dan; Harris, Meredith; Pirkis, Jane; Whiteford, Harvey
2013-06-01
A lack of definitional clarity in supported accommodation and the absence of a widely accepted system for classifying supported accommodation models creates barriers to service planning and evaluation. We undertook a systematic review of existing supported accommodation classification systems. Using a structured system for qualitative data analysis, we reviewed the stratification features in these classification systems, identified the key elements of supported accommodation and arranged them into domains and dimensions to create a new taxonomy. The existing classification systems were mapped onto the new taxonomy to verify the domains and dimensions. Existing classification systems used either a service-level characteristic or programmatic approach. We proposed a taxonomy based around four domains: duration of tenure; patient characteristics; housing characteristics; and service characteristics. All of the domains in the taxonomy were drawn from the existing classification structures; however, none of the existing classification structures covered all of the domains in the taxonomy. Existing classification systems are regionally based, limited in scope and lack flexibility. A domains-based taxonomy can allow more accurate description of supported accommodation services, aid in identifying the service elements likely to improve outcomes for specific patient populations, and assist in service planning.
A High Altitude Ionization Structure and Scintillation Model.
1979-02-19
structure and convection model into an existing systems code. The purpose is to update estimates of the scintillation effects of the structuring of the...OSEC 37.2 Fig. 16. Isodensity contours of plasma density at t - 0 sec. The ini- tial destribution for NJNO is a gaus- sian in y, centered at y - 12.1 km...striations is a task for future work. 35 - . 5. IMPLEMENTATION INTO AN EXISTING CODE In any existing systems code that uses RANC phenomenology, there
NASA Astrophysics Data System (ADS)
Chen, Huabin
2013-08-01
In this paper, the problems about the existence and uniqueness, attraction for strong solution of stochastic age-structured population systems with diffusion and Poisson jump are considered. Under the non-Lipschitz condition with the Lipschitz condition being considered as a special case, the existence and uniqueness for such systems is firstly proved by using the Burkholder-Davis-Gundy inequality (B-D-G inequality) and Itô's formula. And then by using a novel inequality technique, some sufficient conditions ensuring the existence for the domain of attraction are established. As another by-product, the exponential stability in mean square moment of strong solution for such systems can be also discussed.
Information-System Structure by Communication-Technology Concepts: A Cybernetic Model Approach.
ERIC Educational Resources Information Center
Reisig, Gerhard H. R.
1978-01-01
Presents the "Evidence-of-Existence" information system in which the structure is developed, with application of cybernetic concepts, as an isomorphic model in analogy to the system structure of communication technology. Three criteria of structuring are postulated: (1) source-channel-sink, with input-output characteristics, (2) filter-type…
A structural informatics approach to mine kinase knowledge bases.
Brooijmans, Natasja; Mobilio, Dominick; Walker, Gary; Nilakantan, Ramaswamy; Denny, Rajiah A; Feyfant, Eric; Diller, David; Bikker, Jack; Humblet, Christine
2010-03-01
In this paper, we describe a combination of structural informatics approaches developed to mine data extracted from existing structure knowledge bases (Protein Data Bank and the GVK database) with a focus on kinase ATP-binding site data. In contrast to existing systems that retrieve and analyze protein structures, our techniques are centered on a database of ligand-bound geometries in relation to residues lining the binding site and transparent access to ligand-based SAR data. We illustrate the systems in the context of the Abelson kinase and related inhibitor structures. 2009 Elsevier Ltd. All rights reserved.
Scale-invariant entropy-based theory for dynamic ordering
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mahulikar, Shripad P., E-mail: spm@iitmandi.ac.in, E-mail: spm@aero.iitb.ac.in; Department of Aerospace Engineering, Indian Institute of Technology Bombay, Mumbai 400076; Kumari, Priti
2014-09-01
Dynamically Ordered self-organized dissipative structure exists in various forms and at different scales. This investigation first introduces the concept of an isolated embedding system, which embeds an open system, e.g., dissipative structure and its mass and/or energy exchange with its surroundings. Thereafter, scale-invariant theoretical analysis is presented using thermodynamic principles for Order creation, existence, and destruction. The sustainability criterion for Order existence based on its structured mass and/or energy interactions with the surroundings is mathematically defined. This criterion forms the basis for the interrelationship of physical parameters during sustained existence of dynamic Order. It is shown that the sufficient conditionmore » for dynamic Order existence is approached if its sustainability criterion is met, i.e., its destruction path is blocked. This scale-invariant approach has the potential to unify the physical understanding of universal dynamic ordering based on entropy considerations.« less
DOT National Transportation Integrated Search
2011-06-01
Micro-electromechanical systems (MEMS) provide vast improvements over existing sensing methods in the context of structural health monitoring (SHM) of highway infrastructure systems, including improved system reliability, improved longevity and enhan...
NASA Astrophysics Data System (ADS)
Miquel, Benjamin
The dynamic or seismic behavior of hydraulic structures is, as for conventional structures, essential to assure protection of human lives. These types of analyses also aim at limiting structural damage caused by an earthquake to prevent rupture or collapse of the structure. The particularity of these hydraulic structures is that not only the internal displacements are caused by the earthquake, but also by the hydrodynamic loads resulting from fluid-structure interaction. This thesis reviews the existing complex and simplified methods to perform such dynamic analysis for hydraulic structures. For the complex existing methods, attention is placed on the difficulties arising from their use. Particularly, interest is given in this work on the use of transmitting boundary conditions to simulate the semi infinity of reservoirs. A procedure has been developed to estimate the error that these boundary conditions can introduce in finite element dynamic analysis. Depending on their formulation and location, we showed that they can considerably affect the response of such fluid-structure systems. For practical engineering applications, simplified procedures are still needed to evaluate the dynamic behavior of structures in contact with water. A review of the existing simplified procedures showed that these methods are based on numerous simplifications that can affect the prediction of the dynamic behavior of such systems. One of the main objectives of this thesis has been to develop new simplified methods that are more accurate than those existing. First, a new spectral analysis method has been proposed. Expressions for the fundamental frequency of fluid-structure systems, key parameter of spectral analysis, have been developed. We show that this new technique can easily be implemented in a spreadsheet or program, and that its calculation time is near instantaneous. When compared to more complex analytical or numerical method, this new procedure yields excellent prediction of the dynamic behavior of fluid-structure systems. Spectral analyses ignore the transient and oscillatory nature of vibrations. When such dynamic analyses show that some areas of the studied structure undergo excessive stresses, time history analyses allow a better estimate of the extent of these zones as well as a time notion of these excessive stresses. Furthermore, the existing spectral analyses methods for fluid-structure systems account only for the static effect of higher modes. Thought this can generally be sufficient for dams, for flexible structures the dynamic effect of these modes should be accounted for. New methods have been developed for fluid-structure systems to account for these observations as well as the flexibility of foundations. A first method was developed to study structures in contact with one or two finite or infinite water domains. This new technique includes flexibility of structures and foundations as well as the dynamic effect of higher vibration modes and variations of the levels of the water domains. Extension of this method was performed to study beam structures in contact with fluids. These new developments have also allowed extending existing analytical formulations of the dynamic properties of a dry beam to a new formulation that includes effect of fluid-structure interaction. The method yields a very good estimate of the dynamic behavior of beam-fluid systems or beam like structures in contact with fluid. Finally, a Modified Accelerogram Method (MAM) has been developed to modify the design earthquake into a new accelerogram that directly accounts for the effect of fluid-structure interaction. This new accelerogram can therefore be applied directly to the dry structure (i.e. without water) in order to calculate the dynamic response of the fluid-structure system. This original technique can include numerous parameters that influence the dynamic response of such systems and allows to treat analytically the fluid-structure interaction while keeping the advantages of finite element modeling.
Permeability of existing structures for terrestrial wildlife : a passage assessment system.
DOT National Transportation Integrated Search
2011-07-01
"A Passage Assessment System (PAS) was developed to help the Washington Department of : Transportation (WSDOT) evaluate existing transportation infrastructure for its ability to facilitate : terrestrial wildlife movement from one side of a roadway to...
Optimal Alignment of Structures for Finite and Periodic Systems.
Griffiths, Matthew; Niblett, Samuel P; Wales, David J
2017-10-10
Finding the optimal alignment between two structures is important for identifying the minimum root-mean-square distance (RMSD) between them and as a starting point for calculating pathways. Most current algorithms for aligning structures are stochastic, scale exponentially with the size of structure, and the performance can be unreliable. We present two complementary methods for aligning structures corresponding to isolated clusters of atoms and to condensed matter described by a periodic cubic supercell. The first method (Go-PERMDIST), a branch and bound algorithm, locates the global minimum RMSD deterministically in polynomial time. The run time increases for larger RMSDs. The second method (FASTOVERLAP) is a heuristic algorithm that aligns structures by finding the global maximum kernel correlation between them using fast Fourier transforms (FFTs) and fast SO(3) transforms (SOFTs). For periodic systems, FASTOVERLAP scales with the square of the number of identical atoms in the system, reliably finds the best alignment between structures that are not too distant, and shows significantly better performance than existing algorithms. The expected run time for Go-PERMDIST is longer than FASTOVERLAP for periodic systems. For finite clusters, the FASTOVERLAP algorithm is competitive with existing algorithms. The expected run time for Go-PERMDIST to find the global RMSD between two structures deterministically is generally longer than for existing stochastic algorithms. However, with an earlier exit condition, Go-PERMDIST exhibits similar or better performance.
Coherent structures and dynamical systems
NASA Technical Reports Server (NTRS)
Jimenez, Javier
1987-01-01
Any flow of a viscous fluid has a finite number of degrees of freedom, and can therefore be seen as a dynamical system. A coherent structure can be thought of as a lower dimensional manifold in whose neighborhood the dynamical system spends a substantial fraction of its time. If such a manifold exists, and if its dimensionality is substantially lower that that of the full flow, it is conceivable that the flow could be described in terms of the reduced set of degrees of freedom, and that such a description would be simpler than one in which the existence of structure was not recognized. Several examples are briefly summarized.
ERIC Educational Resources Information Center
Kamya, Moses M.
2009-01-01
This dissertation examines an enterprise system appropriation process applying structuration theory and adaptive structuration theory (AST). The key research questions are: (1) what structures emerge from the implementation of enterprise information technology (EIT); (2) how do enterprise technologies and existing organization structures influence…
Carrell, David S; Schoen, Robert E; Leffler, Daniel A; Morris, Michele; Rose, Sherri; Baer, Andrew; Crockett, Seth D; Gourevitch, Rebecca A; Dean, Katie M; Mehrotra, Ateev
2017-09-01
Widespread application of clinical natural language processing (NLP) systems requires taking existing NLP systems and adapting them to diverse and heterogeneous settings. We describe the challenges faced and lessons learned in adapting an existing NLP system for measuring colonoscopy quality. Colonoscopy and pathology reports from 4 settings during 2013-2015, varying by geographic location, practice type, compensation structure, and electronic health record. Though successful, adaptation required considerably more time and effort than anticipated. Typical NLP challenges in assembling corpora, diverse report structures, and idiosyncratic linguistic content were greatly magnified. Strategies for addressing adaptation challenges include assessing site-specific diversity, setting realistic timelines, leveraging local electronic health record expertise, and undertaking extensive iterative development. More research is needed on how to make it easier to adapt NLP systems to new clinical settings. A key challenge in widespread application of NLP is adapting existing systems to new clinical settings. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com
Nonlinear layered lattice model and generalized solitary waves in imperfectly bonded structures.
Khusnutdinova, Karima R; Samsonov, Alexander M; Zakharov, Alexey S
2009-05-01
We study nonlinear waves in a two-layered imperfectly bonded structure using a nonlinear lattice model. The key element of the model is an anharmonic chain of oscillating dipoles, which can be viewed as a basic lattice analog of a one-dimensional macroscopic waveguide. Long nonlinear longitudinal waves in a layered lattice with a soft middle (or bonding) layer are governed by a system of coupled Boussinesq-type equations. For this system we find conservation laws and show that pure solitary waves, which exist in a single equation and can exist in the coupled system in the symmetric case, are structurally unstable and are replaced with generalized solitary waves.
NASA Astrophysics Data System (ADS)
Minakuchi, Shu; Tsukamoto, Haruka; Takeda, Nobuo
2009-03-01
This study proposes novel hierarchical sensing concept for detecting damages in composite structures. In the hierarchical system, numerous three-dimensionally structured sensor devices are distributed throughout the whole structural area and connected with the optical fiber network through transducing mechanisms. The distributed "sensory nerve cell" devices detect the damage, and the fiber optic "spinal cord" network gathers damage signals and transmits the information to a measuring instrument. This study began by discussing the basic concept of the hierarchical sensing system thorough comparison with existing fiber optic based systems and nerve systems in the animal kingdom. Then, in order to validate the proposed sensing concept, impact damage detection system for the composite structure was proposed. The sensor devices were developed based on Comparative Vacuum Monitoring (CVM) system and the Brillouin based distributed strain sensing was utilized to gather the damage signals from the distributed devices. Finally a verification test was conducted using prototype devices. Occurrence of barely visible impact damage was successfully detected and it was clearly indicated that the hierarchical system has better repairability, higher robustness, and wider monitorable area compared to existing systems utilizing embedded optical fiber sensors.
Analysis of technical university information system
NASA Astrophysics Data System (ADS)
Savelyev, N. A.; Boyarkin, M. A.
2018-05-01
The paper covers a set and interaction of the existing higher education institution automated control systems in φ state budgetary educational institution of higher professional education "Industrial University of Tyumen ". A structural interaction of the existing systems and their functions has been analyzed which has become a basis for identification of a number of system-related and local (related to separate modules) drawbacks of the university activities automation. The authors suggested a new structure of the automated control system, consisting of three major subsystems: management support; training and methodology support; distance and supplementary education support. Functionality for each subsystem has been defined in accordance with the educational institution automation requirements. The suggested structure of the ACS will solve the challenges facing the university during reorganization and optimization of the processes of management of the institution activities as a whole.
Iraqi Army Facilities Under the Iraq Security Forces Fund, Diyanah and Debecha, Iraq
2008-01-17
reinforcement bars and cast each building’s roof flatwork and horizontal beams to complete the structural aspects of the roof system . Steel header...included a mix of new construction and renovation of existing structures and facilities. The Statement of Requirements and Specifications provided...that renovation of existing structures , when possible, was preferred. In addition, the United States government encouraged the contractor to use
New Transverse Bunch-by-Bunch Feedback System at TLS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hu, K. H.; Kuo, C. H.; Hsu, S. Y.
2007-01-19
An FPGA based transverse bunch-by-bunch feedback system was implemented and commissioned to replace the existing analog transverse feedback system in order to suppress more effectively multi-bunch instabilities caused by the resistive wall of the vacuum chamber, cavity-like structures and ions related instability. This system replaces existing analog transverse feedback system to enlarge the tunability of the working point. Lower chromaticity is possible with feedback system that is very helpful for injection efficiency improvement. Top-up and high current operation is benefit for this upgrade. One feedback loop suppresses horizontal and vertical multi-bunch instabilities simultaneously. The clean and simple structure makes themore » system simple and reliable. This study also presents the preliminary result of commissioning the new transverse feedback system.« less
Evaluating the Florida Urban Search and Rescue System: Its Future Structure and Direction
2009-12-01
FLORIDA URBAN SEARCH AND RESCUE SYSTEM: ITS FUTURE STRUCTURE AND DIRECTION by John J. DeIorio, II December 2009 Thesis Advisor: Ellen...COVERED Master’s Thesis 4. TITLE AND SUBTITLE Evaluating the Florida Urban Search and Rescue System: Its Future Structure and Direction 6. AUTHOR(S...professional liability, the system is in jeopardy of ceasing to exist. If this were to occur, Florida could not adequately protect its citizens during
Exposure to polystyrene nanoplastic leads to inhibition of anaerobic digestion system.
Fu, Shan-Fei; Ding, Jian-Nan; Zhang, Yun; Li, Yi-Fei; Zhu, Rong; Yuan, Xian-Zheng; Zou, Hua
2018-06-01
In this study, impacts of nanoplastic on the pure and mixed anaerobic digestion systems were investigated. Results showed the growth and metabolism of Acetobacteroides hydrogenigenes were partly inhibited by nanoplastic existed in the pure anaerobic digestion system. The anaerobic digestion of sewage sludge was also obviously inhibited by nanoplastic existed in the mixed anaerobic digestion system. Both the methane yield and methane production rate of the mixed anaerobic digestion system showed negative correlation with the nanoplastic concentration. Compared with anaerobic digestion system without nanoplastic, methane yield and maximum daily methane yield at the nanoplastic concentration of 0.2g/L decreased for 14.4% and 40.7%, respectively. In addition, the start-up of mixed anaerobic digestion system was prolonged by addition of nanoplastic. Microbial community structure analysis indicated the microbial community structures were also affected by nanoplastic existed in the system. At the nanoplastic concentration of 0.2g/L, the relative abundances of family Cloacamonaceae, Porphyromonadaceae, Anaerolinaceae and Gracilibacteraceae decreased partly. Conversely, the relative abundances of family Anaerolinaceae, Clostridiaceae, Geobacteraceae, Dethiosulfovibrionaceae and Desulfobulbaceae improved partly. Copyright © 2017 Elsevier B.V. All rights reserved.
Thermal and structural properties of zinc modified tellurite based glasses
NASA Astrophysics Data System (ADS)
Kundu, R. S.; Dhankhar, Sunil; Punia, R.; Dult, Meenakshi; Kishore, N.
2016-05-01
Glass system 60 TeO2 - 10 B2O3-(30-x) Bi2O3-x ZnO with mole fraction x = 10, 15, 20, 25 and 30 were synthesized by conventional melt quenching technique under controlled atmospheric conditions. The glass transition temperature (Tg) has been determined using differential scanning Calorimetry (DSC) and its value is observed to increase with increase in ZnO content. This increase may be due to the increase in the concentration of the bridging oxygen (BO) atoms. IR and Raman spectra of the present glass system indicate that ZnO acts as network modifier and exists in ZnO4 units. TeO2 exists as TeO3, TeO4, and TeO3+1 structural units. Bismuth plays the role of network modifier with BiO6 octahedral structural units whereas B2O3 exists in the form of BO3 trigonal and BO4 tetrahedral structural units.
de Keizer, N F; Abu-Hanna, A
2000-03-01
This article describes the application of two popular conceptual and formal representation formalisms, as part of a framework for understanding terminological systems. A precise understanding of the structure of a terminological system is essential to assess existing terminological systems, to recognize patterns in various systems and to build new terminological systems. Our experience with the application of this framework to five well-known terminological systems is described.
Design and testing of integrated Bragg grating sensor systems for advanced grid structure
NASA Astrophysics Data System (ADS)
Amano, Masataro; Mizutani, Tadahito; Okabe, Yoji; Takeda, Nobuo; Ozaki, Tsuyoshi
2006-03-01
In this research, the authors target on the construction of structural health monitoring system of Advanced Grid Structure (AGS) made of Carbon fiber reinforced plastic (CFRP). AGS has often been applied to aerospace structures because of the following advantages: (1) Since ribs carry only axial forces, the weakness in the transverse direction of the CFRP unidirectional laminates is negligible. (2) AGS has damage tolerance because the fracture of a rib hardly affects other ribs, namely AGS is a fail-safe structure. In this research, in order to detect existence and regions of rib fractures in AGS, we embedded multiplexed fiber Bragg grating (FBG) sensors into AGS in rib longitudinal directions for measurement of strains. Monitoring of the change in rib longitudinal strains is the most effective SHM system for AGS. In order to confirm our proposal, we carried out following discussions. First, we analytically revealed that the change in rib longitudinal strains was the most sensitive signal for damage detection because of AGS's structural redundancy. Then, we introduced a statistical outlier analysis technique into the SHM system for damage recognition. Finally, we established AGS with the SHM system and verified experimentally. The result of the test showed that damage existence and regions in AGS could be detected with the proposed SHM system.
Inverse Jacobi multiplier as a link between conservative systems and Poisson structures
NASA Astrophysics Data System (ADS)
García, Isaac A.; Hernández-Bermejo, Benito
2017-08-01
Some aspects of the relationship between conservativeness of a dynamical system (namely the preservation of a finite measure) and the existence of a Poisson structure for that system are analyzed. From the local point of view, due to the flow-box theorem we restrict ourselves to neighborhoods of singularities. In this sense, we characterize Poisson structures around the typical zero-Hopf singularity in dimension 3 under the assumption of having a local analytic first integral with non-vanishing first jet by connecting with the classical Poincaré center problem. From the global point of view, we connect the property of being strictly conservative (the invariant measure must be positive) with the existence of a Poisson structure depending on the phase space dimension. Finally, weak conservativeness in dimension two is introduced by the extension of inverse Jacobi multipliers as weak solutions of its defining partial differential equation and some of its applications are developed. Examples including Lotka-Volterra systems, quadratic isochronous centers, and non-smooth oscillators are provided.
The Optimization of In-Memory Space Partitioning Trees for Cache Utilization
NASA Astrophysics Data System (ADS)
Yeo, Myung Ho; Min, Young Soo; Bok, Kyoung Soo; Yoo, Jae Soo
In this paper, a novel cache conscious indexing technique based on space partitioning trees is proposed. Many researchers investigated efficient cache conscious indexing techniques which improve retrieval performance of in-memory database management system recently. However, most studies considered data partitioning and targeted fast information retrieval. Existing data partitioning-based index structures significantly degrade performance due to the redundant accesses of overlapped spaces. Specially, R-tree-based index structures suffer from the propagation of MBR (Minimum Bounding Rectangle) information by updating data frequently. In this paper, we propose an in-memory space partitioning index structure for optimal cache utilization. The proposed index structure is compared with the existing index structures in terms of update performance, insertion performance and cache-utilization rate in a variety of environments. The results demonstrate that the proposed index structure offers better performance than existing index structures.
Passive Vibration Control of Existing Structures by Gravity-Loaded Cables
NASA Astrophysics Data System (ADS)
Alvis, E.; Tsang, H. H.; Hashemi, M. J.
2017-06-01
Structures with high concentration of mass at or close to the top such as highway bridge piers are vulnerable in earthquakes or accidents. In this paper, a simple and convenient retrofit strategy is proposed for minimizing vibrations and damages, extending service life and preventing collapse of existing structures. The proposed system comprises of tension-only cables secured to the sides of the structure through gravity anchor blocks that are free to move in vertical shafts. The system is installed in such a way that the cables do not induce unnecessary stress on the main structure when there is no lateral motion or vibration. The effectiveness of controlling global structural responses is investigated for tension-only bilinear-elastic behaviour of cables. Results of a realistic case study for a reinforced concrete bridge pier show that response reduction is remarkably well under seismic excitation.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-20
... Facilities and Phase I Facilities AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule...) of the Clean Water Act for all existing power generating facilities and existing manufacturing and industrial facilities. EPA requested that public comments on the proposal be submitted on or before July 19...
Interdisciplinary design study of a high-rise integrated roof wind energy system
NASA Astrophysics Data System (ADS)
Dekker, R. W. A.; Ferraro, R. M.; Suma, A. B.; Moonen, S. P. G.
2012-10-01
Today's market in micro-wind turbines is in constant development introducing more efficient solutions for the future. Besides the private use of tower supported turbines, opportunities to integrate wind turbines in the built environment arise. The Integrated Roof Wind Energy System (IRWES) presented in this work is a modular roof structure integrated on top of existing or new buildings. IRWES is build up by an axial array of skewed shaped funnels used for both wind inlet and outlet. This inventive use of shape and geometry leads to a converging air capturing inlet to create high wind mass flow and velocity toward a Vertical Axis Wind Turbine (VAWT) in the center-top of the roof unit for the generation of a relatively high amount of energy. The scope of this research aims to make an optimized structural design of IRWES to be placed on top of the Vertigo building in Eindhoven; analysis of the structural performance; and impact to the existing structure by means of Finite Element Modeling (FEM). Results show that the obvious impact of wind pressure to the structural design is easily supported in different configurations of fairly simple lightweight structures. In particular, the weight addition to existing buildings remains minimal.
Zhiyong Cai; Robert J. Ross; Michael O. Hunt; Lawrence A. Soltis
2002-01-01
Evaluation of existing timber structures requires procedures to evaluate in situ structural members and components. This report evaluates the transverse vibration response of laboratory-built floor systems with new and salvaged joists. The objectives were to 1) compare floor system response to individual member response; 2) examine response sensitivity to location of...
Hamiltonian structure of the Lotka-Volterra equations
NASA Astrophysics Data System (ADS)
Nutku, Y.
1990-03-01
The Lotka-Volterra equations governing predator-prey relations are shown to admit Hamiltonian structure with respect to a generalized Poisson bracket. These equations provide an example of a system for which the naive criterion for the existence of Hamiltonian structure fails. We show further that there is a three-component generalization of the Lotka-Volterra equations which is a bi-Hamiltonian system.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-12
...-5] RIN 2040-AE95 National Pollutant Discharge Elimination System--Proposed Regulations To Establish Requirements for Cooling Water Intake Structures at Existing Facilities; Notice of Data Availability Related to... availability. SUMMARY: On April 20, 2011, EPA published proposed standards for cooling water intake structures...
NASA Astrophysics Data System (ADS)
Maznev, A. A.; Every, A. G.
2018-01-01
We study the existence of guided acoustic modes in layered structures whose phase velocity is higher than that of bulk waves in a solid substrate or an adjacent fluid half space, which belong to the class of bound states in the radiation continuum (BICs). We demonstrate that in contrast to the electromagnetic case, non-symmetry-protected BICs exist in isotropic layered systems without periodic structures. Two systems supporting non-symmetry-protected sagittally polarized BICs have been identified: (i) a supported solid layer yields BICs whose phase velocity is higher than the transverse velocity of the substrate but lower than the longitudinal velocity; (ii) a supported solid layer loaded by a fluid half space supports BICs whose velocity is higher that the bulk velocity of the fluid but lower than acoustic velocities of the substrate. The latter case is a unique example of BICs in the sense that it does not involve an evanescent field in the fluid half space providing the radiation continuum. In either case, BICs are represented by isolated points in the dispersion relations located within "leaky" branches. We show that these BICs are robust with respect to small perturbations of the system parameters. Numerical results are provided for realistic materials combinations. We also show that no BICs exist in all-fluid layered structures, whereas in solid layered structures there are no shear horizontal BICs and no sagittally polarized BICs whose velocity exceeds the longitudinal velocity of the substrate.
Factors for change in maternal and perinatal audit systems in Dar es Salaam hospitals, Tanzania.
Nyamtema, Angelo S; Urassa, David P; Pembe, Andrea B; Kisanga, Felix; van Roosmalen, Jos
2010-06-03
Effective maternal and perinatal audits are associated with improved quality of care and reduction of severe adverse outcome. Although audits at the level of care were formally introduced in Tanzania around 25 years ago, little information is available about their existence, performance, and practical barriers to their implementation. This study assessed the structure, process and impacts of maternal and perinatal death audit systems in clinical practice and presents a detailed account on how they could be improved. A cross sectional descriptive study was conducted in eight major hospitals in Dar es Salaam in January 2009. An in-depth interview guide was used for 29 health managers and members of the audit committees to investigate the existence, structure, process and outcome of such audits in clinical practice. A semi-structured questionnaire was used to interview 30 health care providers in the maternity wards to assess their awareness, attitude and practice towards audit systems. The 2007 institutional pregnancy outcome records were reviewed. Overall hospital based maternal mortality ratio was 218/100,000 live births (range: 0 - 385) and perinatal mortality rate was 44/1000 births (range: 17 - 147). Maternal and perinatal audit systems existed only in 4 and 3 hospitals respectively, and key decision makers did not take part in audit committees. Sixty percent of care providers were not aware of even a single action which had ever been implemented in their hospitals because of audit recommendations. There were neither records of the key decision points, action plan, nor regular analysis of the audit reports in any of the facilities where such audit systems existed. Maternal and perinatal audit systems in these institutions are poorly established in structure and process; and are less effective to improve the quality of care. Fundamental changes are urgently needed for successful audit systems in these institutions.
75 FR 62008 - Safety Management System for Certificated Airports
Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-07
.... The majority of pilot study airports indicated an existing organizational structure to manage safety... organizational structure; Identifies the lines of safety responsibility and accountability; Establishes and... understands that airport operations and organizational structures vary widely. Accordingly, the FAA would not...
Structural and lithologic study of northern California Coast Range and Sacramento Valley, California
NASA Technical Reports Server (NTRS)
Rich, E. I. (Principal Investigator); Steele, W. C.
1973-01-01
The author has identified the following significant results. Photgeologic examination of repetitive multispectral ERTS-1 imagery of Northern California has disclosed several systems of linear features which may be important for the interpretation of the structural history of California. They are separated from an orthogonal system of linears in the Klamath Mts. by a set of discontinuous southeast-trending linear features (the Mendocino system) which is traceable from the Pacific Coast, at Cape Mendocino, into the eastern foothills of the Sierra Nevada. Within the Sierra Nevada, the Mendocino system separates the north-trending Sierran system from a set of linears characteristic of the Modoc Plateau. With minor exception, little overlap exists among the systems which suggests a decipherable chronology and evolutionary history for the region. The San Andres system of linears appears to truncate or co-exist with most of the other systems in the northern Coast Ranges. The Mendocino system truncates the Klamath, Sierran, and Modoc systems. The Sierran system may represent fundamental and long-persisting pre-late Paleozoic zones of crustal weakness which have been reactivated from time to time. The Mendocino system was possibly developed in early Mesozoic and is important to the structural framework of Northern California.
Boko Haram: A Systemic and Strategic Analysis
2016-06-01
21 5 Example Structural System Model …..……………………………….…………21 6 Interconnections ...…………………………………………………….…………23 vii 7...result from exogenous, endogenous, or structural factors. Endogenous factors exist within the geographical bounds of the system state, but exogenous...of the system, the structural factors are a result of the anarchic nature of the international system. Changes in system states reveal long-term
On the problem of modeling for parameter identification in distributed structures
NASA Technical Reports Server (NTRS)
Norris, Mark A.; Meirovitch, Leonard
1988-01-01
Structures are often characterized by parameters, such as mass and stiffness, that are spatially distributed. Parameter identification of distributed structures is subject to many of the difficulties involved in the modeling problem, and the choice of the model can greatly affect the results of the parameter identification process. Analogously to control spillover in the control of distributed-parameter systems, identification spillover is shown to exist as well and its effect is to degrade the parameter estimates. Moreover, as in modeling by the Rayleigh-Ritz method, it is shown that, for a Rayleigh-Ritz type identification algorithm, an inclusion principle exists in the identification of distributed-parameter systems as well, so that the identified natural frequencies approach the actual natural frequencies monotonically from above.
NASA Astrophysics Data System (ADS)
Sun, Xiuting; Jing, Xingjian
2016-12-01
This study investigates theoretically and experimentally a vibration isolator constructed by an n-layer Scissor-Like Structure (SLS), focusing on the analysis and design of nonlinear stiffness and damping characteristics for advantageous isolation performance in both orthogonal directions. With the mathematical modeling, the influence incurred by different structural parameters on system isolation performance is studied. It is shown that, (a) nonlinear high-static-low-dynamic stiffness and damping characteristics can be seen such that the system can achieve good isolation performance in both directions, (b) an anti-resonance frequency band exists due to the coupling effect between the linear and nonlinear stiffness in the two orthogonal directions within the structure, and (c) all these performances are designable with several structural parameters. The advantages of the proposed system are shown through comparisons with an existing quasi-zero-stiffness vibration isolator (QZS-VI) and a traditional mass-spring-damper vibration isolator (MSD-VI), and further validated by experimental results.
2011-07-01
velocity/substrate Excavate back channels in river systems Piers & Wharves Design hard structures to facilitate better seaweed recruitment...allows vegetative colonization of areas beneath the structures P Design hard structures to facilitate better seaweed recruitment I Provide
Comparison of Content Structure and Cognitive Structure in the Learning of Probability.
ERIC Educational Resources Information Center
Geeslin, William E.
Digraphs, graphs, and task analysis were used to map out the content structure of a programed text (SMSG) in elementary probability. Mathematical structure was defined as the relationship between concepts within a set of abstract systems. The word association technique was used to measure the existing relations (cognitive structure) in S's memory…
Identifying States of a Financial Market
NASA Astrophysics Data System (ADS)
Münnix, Michael C.; Shimada, Takashi; Schäfer, Rudi; Leyvraz, Francois; Seligman, Thomas H.; Guhr, Thomas; Stanley, H. Eugene
2012-09-01
The understanding of complex systems has become a central issue because such systems exist in a wide range of scientific disciplines. We here focus on financial markets as an example of a complex system. In particular we analyze financial data from the S&P 500 stocks in the 19-year period 1992-2010. We propose a definition of state for a financial market and use it to identify points of drastic change in the correlation structure. These points are mapped to occurrences of financial crises. We find that a wide variety of characteristic correlation structure patterns exist in the observation time window, and that these characteristic correlation structure patterns can be classified into several typical ``market states''. Using this classification we recognize transitions between different market states. A similarity measure we develop thus affords means of understanding changes in states and of recognizing developments not previously seen.
Identifying states of a financial market.
Münnix, Michael C; Shimada, Takashi; Schäfer, Rudi; Leyvraz, Francois; Seligman, Thomas H; Guhr, Thomas; Stanley, H Eugene
2012-01-01
The understanding of complex systems has become a central issue because such systems exist in a wide range of scientific disciplines. We here focus on financial markets as an example of a complex system. In particular we analyze financial data from the S&P 500 stocks in the 19-year period 1992-2010. We propose a definition of state for a financial market and use it to identify points of drastic change in the correlation structure. These points are mapped to occurrences of financial crises. We find that a wide variety of characteristic correlation structure patterns exist in the observation time window, and that these characteristic correlation structure patterns can be classified into several typical "market states". Using this classification we recognize transitions between different market states. A similarity measure we develop thus affords means of understanding changes in states and of recognizing developments not previously seen.
Mathematical structure of unit systems
NASA Astrophysics Data System (ADS)
Kitano, Masao
2013-05-01
We investigate the mathematical structure of unit systems and the relations between them. Looking over the entire set of unit systems, we can find a mathematical structure that is called preorder (or quasi-order). For some pair of unit systems, there exists a relation of preorder such that one unit system is transferable to the other unit system. The transfer (or conversion) is possible only when all of the quantities distinguishable in the latter system are always distinguishable in the former system. By utilizing this structure, we can systematically compare the representations in different unit systems. Especially, the equivalence class of unit systems (EUS) plays an important role because the representations of physical quantities and equations are of the same form in unit systems belonging to an EUS. The dimension of quantities is uniquely defined in each EUS. The EUS's form a partially ordered set. Using these mathematical structures, unit systems and EUS's are systematically classified and organized as a hierarchical tree.
Design and realization of tourism spatial decision support system based on GIS
NASA Astrophysics Data System (ADS)
Ma, Zhangbao; Qi, Qingwen; Xu, Li
2008-10-01
In this paper, the existing problems of current tourism management information system are analyzed. GIS, tourism as well as spatial decision support system are introduced, and the application of geographic information system technology and spatial decision support system to tourism management and the establishment of tourism spatial decision support system based on GIS are proposed. System total structure, system hardware and software environment, database design and structure module design of this system are introduced. Finally, realization methods of this systemic core functions are elaborated.
Local atomic and magnetic structure of dilute magnetic semiconductor (Ba ,K ) (Zn,Mn ) 2As2
NASA Astrophysics Data System (ADS)
Frandsen, Benjamin A.; Gong, Zizhou; Terban, Maxwell W.; Banerjee, Soham; Chen, Bijuan; Jin, Changqing; Feygenson, Mikhail; Uemura, Yasutomo J.; Billinge, Simon J. L.
2016-09-01
We have studied the atomic and magnetic structure of the dilute ferromagnetic semiconductor system (Ba ,K )(Zn ,Mn )2As2 through atomic and magnetic pair distribution function analysis of temperature-dependent x-ray and neutron total scattering data. We detected a change in curvature of the temperature-dependent unit cell volume of the average tetragonal crystallographic structure at a temperature coinciding with the onset of ferromagnetic order. We also observed the existence of a well-defined local orthorhombic structure on a short length scale of ≲5 Å , resulting in a rather asymmetrical local environment of the Mn and As ions. Finally, the magnetic PDF revealed ferromagnetic alignment of Mn spins along the crystallographic c axis, with robust nearest-neighbor ferromagnetic correlations that exist even above the ferromagnetic ordering temperature. We discuss these results in the context of other experiments and theoretical studies on this system.
An artificial intelligence-based structural health monitoring system for aging aircraft
NASA Technical Reports Server (NTRS)
Grady, Joseph E.; Tang, Stanley S.; Chen, K. L.
1993-01-01
To reduce operating expenses, airlines are now using the existing fleets of commercial aircraft well beyond their originally anticipated service lives. The repair and maintenance of these 'aging aircraft' has therefore become a critical safety issue, both to the airlines and the Federal Aviation Administration. This paper presents the results of an innovative research program to develop a structural monitoring system that will be used to evaluate the integrity of in-service aerospace structural components. Currently in the final phase of its development, this monitoring system will indicate when repair or maintenance of a damaged structural component is necessary.
Cherif, Alhaji
2015-09-01
Many important pathogens such as HIV/AIDS, influenza, malaria, dengue and meningitis generally exist in phenotypically distinct serotypes that compete for hosts. Models used to study these diseases appear as meta-population systems. Herein, we revisit one of the multiple strain models that have been used to investigate the dynamics of infectious diseases with co-circulating serotypes or strains, and provide analytical results underlying the numerical investigations. In particular, we establish the necessary conditions for the local asymptotic stability of the steady states and for the existence of oscillatory behaviors via Hopf bifurcation. In addition, we show that the existence of discrete antigenic forms among pathogens can either fully or partially self-organize, where (i) strains exhibit no strain structures and coexist or (ii) antigenic variants sort into non-overlapping or minimally overlapping clusters that either undergo the principle of competitive exclusion exhibiting discrete strain structures, or co-exist cyclically. Copyright © 2015. Published by Elsevier Inc.
Chimera States in Continuous Media: Existence and Distinctness
NASA Astrophysics Data System (ADS)
Nicolaou, Zachary G.; Riecke, Hermann; Motter, Adilson E.
2017-12-01
The defining property of chimera states is the coexistence of coherent and incoherent domains in systems that are structurally and spatially homogeneous. The recent realization that such states might be common in oscillator networks raises the question of whether an analogous phenomenon can occur in continuous media. Here, we show that chimera states can exist in continuous systems even when the coupling is strictly local, as in many fluid and pattern forming media. Using the complex Ginzburg-Landau equation as a model system, we characterize chimera states consisting of a coherent domain of a frozen spiral structure and an incoherent domain of amplitude turbulence. We show that in this case, in contrast with discrete network systems, fluctuations in the local coupling field play a crucial role in limiting the coherent regions. We suggest these findings shed light on new possible forms of coexisting order and disorder in fluid systems.
Graduating to Postdoc: Information-Sharing in Support of Organizational Structures and Needs
NASA Technical Reports Server (NTRS)
Keller, Richard M.; Lucas, Paul J.; Compton, Michael M.; Stewart, Helen J.; Baya, Vinod; DelAlto, Martha
1999-01-01
The deployment of information-sharing systems in large organizations can significantly impact existing policies and procedures with regard to authority and control over information. Unless information-sharing systems explicitly support organizational structures and needs, these systems will be rejected summarily. The Postdoc system is a deployed Web-based information-sharing system created specifically to address organizational needs. Postdoc contains various organizational support features including a shared, globally navigable document space, as well as specialized access control, distributed administration, and mailing list features built around the key notion of hierarchical group structures. We review successes and difficulties in supporting organizational needs with Postdoc
DOT National Transportation Integrated Search
2011-01-01
The increasing emphasis on the maintenance of existing infrastructure systems have led to : greater use of advanced sensors and condition monitoring systems. Wireless sensors and : sensor networks are emerging as sensing paradigms that the structural...
10 CFR 70.72 - Facility changes and change process.
Code of Federal Regulations, 2010 CFR
2010-01-01
... management system to evaluate, implement, and track each change to the site, structures, processes, systems, equipment, components, computer programs, and activities of personnel. This system must be documented in... licensed material; (3) Modifications to existing operating procedures including any necessary training or...
10 CFR 70.72 - Facility changes and change process.
Code of Federal Regulations, 2011 CFR
2011-01-01
... management system to evaluate, implement, and track each change to the site, structures, processes, systems, equipment, components, computer programs, and activities of personnel. This system must be documented in... licensed material; (3) Modifications to existing operating procedures including any necessary training or...
10 CFR 70.72 - Facility changes and change process.
Code of Federal Regulations, 2012 CFR
2012-01-01
... management system to evaluate, implement, and track each change to the site, structures, processes, systems, equipment, components, computer programs, and activities of personnel. This system must be documented in... licensed material; (3) Modifications to existing operating procedures including any necessary training or...
10 CFR 70.72 - Facility changes and change process.
Code of Federal Regulations, 2014 CFR
2014-01-01
... management system to evaluate, implement, and track each change to the site, structures, processes, systems, equipment, components, computer programs, and activities of personnel. This system must be documented in... licensed material; (3) Modifications to existing operating procedures including any necessary training or...
10 CFR 70.72 - Facility changes and change process.
Code of Federal Regulations, 2013 CFR
2013-01-01
... management system to evaluate, implement, and track each change to the site, structures, processes, systems, equipment, components, computer programs, and activities of personnel. This system must be documented in... licensed material; (3) Modifications to existing operating procedures including any necessary training or...
2013-09-01
existing MR scanning systems providing the ability to visualize structures that are impossible with current methods . Using techniques to concurrently...and unique system for analysis of affected brain regions and coupled with other imaging techniques and molecular measurements holds significant...scanning systems providing the ability to visualize structures that are impossible with current methods . Using techniques to concurrently stain
Exploration of tetrahedral structures in silicate cathodes using a motif-network scheme
Zhao, Xin; Wu, Shunqing; Lv, Xiaobao; Nguyen, Manh Cuong; Wang, Cai-Zhuang; Lin, Zijing; Zhu, Zi-Zhong; Ho, Kai-Ming
2015-01-01
Using a motif-network search scheme, we studied the tetrahedral structures of the dilithium/disodium transition metal orthosilicates A2MSiO4 with A = Li or Na and M = Mn, Fe or Co. In addition to finding all previously reported structures, we discovered many other different tetrahedral-network-based crystal structures which are highly degenerate in energy. These structures can be classified into structures with 1D, 2D and 3D M-Si-O frameworks. A clear trend of the structural preference in different systems was revealed and possible indicators that affect the structure stabilities were introduced. For the case of Na systems which have been much less investigated in the literature relative to the Li systems, we predicted their ground state structures and found evidence for the existence of new structural motifs. PMID:26497381
Application of structured analysis to a telerobotic system
NASA Technical Reports Server (NTRS)
Dashman, Eric; Mclin, David; Harrison, F. W.; Soloway, Donald; Young, Steven
1990-01-01
The analysis and evaluation of a multiple arm telerobotic research and demonstration system developed by the NASA Intelligent Systems Research Laboratory (ISRL) is described. Structured analysis techniques were used to develop a detailed requirements model of an existing telerobotic testbed. Performance models generated during this process were used to further evaluate the total system. A commercial CASE tool called Teamwork was used to carry out the structured analysis and development of the functional requirements model. A structured analysis and design process using the ISRL telerobotic system as a model is described. Evaluation of this system focused on the identification of bottlenecks in this implementation. The results demonstrate that the use of structured methods and analysis tools can give useful performance information early in a design cycle. This information can be used to ensure that the proposed system meets its design requirements before it is built.
The Structure of Positive Interpersonal Relations in Small Groups.
ERIC Educational Resources Information Center
Davis, James A.; Leinhardt, Samuel
The authors sought to test Homans' proposition that small groups inevitably generate a social structure which combines subgroups (cliques) and a ranking system. We present a graph theoretical model of such a structure and prove that a necessary and sufficient condition for its existence is the absence of seven particular triad types. Expected…
Shear-induced structural transitions in Newtonian non-Newtonian two-phase flow
NASA Astrophysics Data System (ADS)
Cristobal, G.; Rouch, J.; Colin, A.; Panizza, P.
2000-09-01
We show the existence under shear flow of steady states in a two-phase region of a brine-surfactant system in which lyotropic dilute lamellar (non-Newtonian) and sponge (Newtonian) phases are coexisting. At high shear rates and low sponge phase-volume fractions, we report on the existence of a dynamic transition corresponding to the formation of a colloidal crystal of multilamellar vesicles (or ``onions'') immersed in the sponge matrix. As the sponge phase-volume fraction increases, this transition exhibits a hysteresis loop leading to a structural bistability of the two-phase flow. Contrary to single phase lamellar systems where it is always 100%, the onion volume fraction can be monitored continuously from 0 to 100 %.
On the phase space structure of IP3 induced Ca2+ signalling and concepts for predictive modeling
NASA Astrophysics Data System (ADS)
Falcke, Martin; Moein, Mahsa; TilÅ«naitÄ--, Agne; Thul, Rüdiger; Skupin, Alexander
2018-04-01
The correspondence between mathematical structures and experimental systems is the basis of the generalizability of results found with specific systems and is the basis of the predictive power of theoretical physics. While physicists have confidence in this correspondence, it is less recognized in cellular biophysics. On the one hand, the complex organization of cellular dynamics involving a plethora of interacting molecules and the basic observation of cell variability seem to question its possibility. The practical difficulties of deriving the equations describing cellular behaviour from first principles support these doubts. On the other hand, ignoring such a correspondence would severely limit the possibility of predictive quantitative theory in biophysics. Additionally, the existence of functional modules (like pathways) across cell types suggests also the existence of mathematical structures with comparable universality. Only a few cellular systems have been sufficiently investigated in a variety of cell types to follow up these basic questions. IP3 induced Ca2+signalling is one of them, and the mathematical structure corresponding to it is subject of ongoing discussion. We review the system's general properties observed in a variety of cell types. They are captured by a reaction diffusion system. We discuss the phase space structure of its local dynamics. The spiking regime corresponds to noisy excitability. Models focussing on different aspects can be derived starting from this phase space structure. We discuss how the initial assumptions on the set of stochastic variables and phase space structure shape the predictions of parameter dependencies of the mathematical models resulting from the derivation.
How To Choose the Right Roofing System.
ERIC Educational Resources Information Center
Carl, David
2001-01-01
Lists the factors that must be considered when specifying a roof for an existing or new facility. Factors discussed include cost, longevity, value of operations, warranties, building structure and design, and old vs. new system compatibility. (GR)
Multi-Agent Systems Design for Novices
ERIC Educational Resources Information Center
Lynch, Simon; Rajendran, Keerthi
2005-01-01
Advanced approaches to the construction of software systems can present difficulties to learners. This is true for multi-agent systems (MAS) which exhibit concurrency, non-determinacy of structure and composition and sometimes emergent behavior characteristics. Additional barriers exist for learners because mainstream MAS technology is young and…
Graph-based real-time fault diagnostics
NASA Technical Reports Server (NTRS)
Padalkar, S.; Karsai, G.; Sztipanovits, J.
1988-01-01
A real-time fault detection and diagnosis capability is absolutely crucial in the design of large-scale space systems. Some of the existing AI-based fault diagnostic techniques like expert systems and qualitative modelling are frequently ill-suited for this purpose. Expert systems are often inadequately structured, difficult to validate and suffer from knowledge acquisition bottlenecks. Qualitative modelling techniques sometimes generate a large number of failure source alternatives, thus hampering speedy diagnosis. In this paper we present a graph-based technique which is well suited for real-time fault diagnosis, structured knowledge representation and acquisition and testing and validation. A Hierarchical Fault Model of the system to be diagnosed is developed. At each level of hierarchy, there exist fault propagation digraphs denoting causal relations between failure modes of subsystems. The edges of such a digraph are weighted with fault propagation time intervals. Efficient and restartable graph algorithms are used for on-line speedy identification of failure source components.
Tool for simplifying the complex interactions within resilient communities
NASA Astrophysics Data System (ADS)
Stwertka, C.; Albert, M. R.; White, K. D.
2016-12-01
In recent decades, scientists have observed and documented impacts from climate change that will impact multiple sectors, will be impacted by decisions from multiple sectors, and will change over time. This complex human-engineered system has a large number of moving, interacting parts, which are interdependent and evolve over time towards their purpose. Many of the existing resilience frameworks and vulnerability frameworks focus on interactions between the domains, but do not include the structure of the interactions. We present an engineering systems approach to investigate the structural elements that influence a community's ability to be resilient. In this presentation we will present and analyze four common methods for building community resilience, utilizing our common framework. For several existing case studies we examine the stress points in the system and identify the impacts on the outcomes from the case studies. In ongoing research we will apply our system tool to a new case in the field.
Stress Transfer and Structural Failure of Bilayered Material Systems
NASA Astrophysics Data System (ADS)
Prieto-Munoz, Pablo Arthur
Bilayered material systems are common in naturally formed or artificially engineered structures. Understanding how loads transfer within these structural systems is necessary to predict failure and develop effective designs. Existing methods for evaluating the stress transfer in bilayered materials are limited to overly simplified models or require experimental calibration. As a result, these methods have failed to accurately account for such structural failures as the creep induced roofing panel collapse of Boston's I-90 connector tunnel, which was supported by adhesive anchors. The one-dimensional stress analyses currently used for adhesive anchor design cannot account for viscoelastic creep failure, and consequently results in dangerously under-designed structural systems. In this dissertation, a method for determining the two-dimensional stress and displacement fields for a generalized bilayered material system is developed, and proposes a closed-form analytical solution. A general linear-elastic solution is first proposed by decoupling the elastic governing equations from one another through the so-called plane assumption. Based on this general solution, an axisymmetric problem and a plane strain problem are formulated. These are applied to common bilayered material systems such as: (1) concrete adhesive anchors, (2) material coatings, (3) asphalt pavements, and (4) layered sedimentary rocks. The stress and displacement fields determined by this analytical analysis are validated through the use of finite element models. Through the correspondence principle, the linear-elastic solution is extended to consider time-dependent viscoelastic material properties, thus facilitating the analysis of adhesive anchors and asphalt pavements while incorporating their viscoelastic material behavior. Furthermore, the elastic stress analysis can explain the fracturing phenomenon of material coatings, pavements, and layered rocks, successfully predicting their fracture saturation ratio---which is the ratio of fracture spacing to the thickness of the weak layer where an increase in load will not cause any new fractures to form. Moreover, these specific material systems are looked at in the context of existing and novel experimental results, further demonstrating the advantage of the stress transfer analysis proposed. This research provides a closed-form stress solution for various structural systems that is applied to different failure analyses. The versatility of this method is in the flexibility and the ease upon which the stress and displacement field results can be applied to existing stress- or displacement-based structural failure criteria. As presented, this analysis can be directly used to: (1) design adhesive anchoring systems for long-term creep loading, (2) evaluate the fracture mechanics behind bilayered material coatings and pavement overlay systems, and (3) determine the fracture spacing to layer thickness ratio of layered sedimentary rocks. As is shown in the four material systems presented, this general solution has far reaching applications in facilitating design and analysis of typical bilayered structural systems.
NASA Astrophysics Data System (ADS)
Wu, Hong; Li, Peng; Li, Yulong
2016-02-01
This paper describes the calculation method for unsteady state conditions in the secondary air systems in gas turbines. The 1D-3D-Structure coupled method was applied. A 1D code was used to model the standard components that have typical geometric characteristics. Their flow and heat transfer were described by empirical correlations based on experimental data or CFD calculations. A 3D code was used to model the non-standard components that cannot be described by typical geometric languages, while a finite element analysis was carried out to compute the structural deformation and heat conduction at certain important positions. These codes were coupled through their interfaces. Thus, the changes in heat transfer and structure and their interactions caused by exterior disturbances can be reflected. The results of the coupling method in an unsteady state showed an apparent deviation from the existing data, while the results in the steady state were highly consistent with the existing data. The difference in the results in the unsteady state was caused primarily by structural deformation that cannot be predicted by the 1D method. Thus, in order to obtain the unsteady state performance of a secondary air system more accurately and efficiently, the 1D-3D-Structure coupled method should be used.
Dissipative structure and global existence in critical space for Timoshenko system of memory type
NASA Astrophysics Data System (ADS)
Mori, Naofumi
2018-08-01
In this paper, we consider the initial value problem for the Timoshenko system with a memory term in one dimensional whole space. In the first place, we consider the linearized system: applying the energy method in the Fourier space, we derive the pointwise estimate of the solution in the Fourier space, which first gives the optimal decay estimate of the solution. Next, we give a characterization of the dissipative structure of the system by using the spectral analysis, which confirms our pointwise estimate is optimal. In the second place, we consider the nonlinear system: we show that the global-in-time existence and uniqueness result could be proved in the minimal regularity assumption in the critical Sobolev space H2. In the proof we don't need any time-weighted norm as recent works; we use just an energy method, which is improved to overcome the difficulties caused by regularity-loss property of Timoshenko system.
Kreimeyer, Kory; Foster, Matthew; Pandey, Abhishek; Arya, Nina; Halford, Gwendolyn; Jones, Sandra F; Forshee, Richard; Walderhaug, Mark; Botsis, Taxiarchis
2017-09-01
We followed a systematic approach based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses to identify existing clinical natural language processing (NLP) systems that generate structured information from unstructured free text. Seven literature databases were searched with a query combining the concepts of natural language processing and structured data capture. Two reviewers screened all records for relevance during two screening phases, and information about clinical NLP systems was collected from the final set of papers. A total of 7149 records (after removing duplicates) were retrieved and screened, and 86 were determined to fit the review criteria. These papers contained information about 71 different clinical NLP systems, which were then analyzed. The NLP systems address a wide variety of important clinical and research tasks. Certain tasks are well addressed by the existing systems, while others remain as open challenges that only a small number of systems attempt, such as extraction of temporal information or normalization of concepts to standard terminologies. This review has identified many NLP systems capable of processing clinical free text and generating structured output, and the information collected and evaluated here will be important for prioritizing development of new approaches for clinical NLP. Copyright © 2017 Elsevier Inc. All rights reserved.
Emergent quasicrystals in strongly correlated systems
NASA Astrophysics Data System (ADS)
Sagi, Eran; Nussinov, Zohar
2016-07-01
Commensurability is of paramount importance in numerous strongly interacting electronic systems. In the fractional quantum Hall effect, a rich cascade of increasingly narrow plateaux appear at larger denominator filling fractions. Rich commensurate structures also emerge, at certain filling fractions, in high temperature superconductors and other electronic systems. A natural question concerns the character of these and other electronic systems at irrational filling fractions. Here we demonstrate that quasicrystalline structures naturally emerge in these situations, and trigger behaviors not typically expected of periodic systems. We first show that irrationally filled quantum Hall systems cross over into quasiperiodically ordered configuration in the thin-torus limit. Using known properties of quasicrystals, we argue that these states are unstable against the effects of disorder, in agreement with the existence of quantum Hall plateaux. We then study analogous physical situations in a system of cold Rydberg atoms placed on an optical lattice. Such an experimental setup is generally disorder free, and can therefore be used to detect the emergent quasicrystals we predict. We discuss similar situations in the Falicov-Kimball model, where known exact results can be used to establish quasicrystalline structures in one and two dimensions. We briefly speculate on possible relations between our theoretical findings and the existence of glassy dynamics and other features of strongly correlated electronic systems.
78 FR 40553 - Privacy Act of 1974: Republication of Notice of Systems of Records
Federal Register 2010, 2011, 2012, 2013, 2014
2013-07-05
...In accordance with 5 U.S.C. 552a(e)(4), the Tennessee Valley Authority (TVA) is republishing in full a notice of the existence and character of each TVA system of records. TVA is correcting minor typographical and stylistic errors in previously existing notices and has updated those notices to reflect current organizational structure. Also, updates are being made to show any changes to system locations; managers and addresses; categories of individuals and records; procedures and practices for storing, retrieving, accessing, retaining, and disposing of records.
NASA Astrophysics Data System (ADS)
Wei, Xiaojun; Živanović, Stana
2018-05-01
The aim of this paper is to propose a novel theoretical framework for dynamic identification in a structure occupied by a single human. The framework enables the prediction of the dynamics of the human-structure system from the known properties of the individual system components, the identification of human body dynamics from the known dynamics of the empty structure and the human-structure system and the identification of the properties of the structure from the known dynamics of the human and the human-structure system. The novelty of the proposed framework is the provision of closed-form solutions in terms of frequency response functions obtained by curve fitting measured data. The advantages of the framework over existing methods are that there is neither need for nonlinear optimisation nor need for spatial/modal models of the empty structure and the human-structure system. In addition, the second-order perturbation method is employed to quantify the effect of uncertainties in human body dynamics on the dynamic identification of the empty structure and the human-structure system. The explicit formulation makes the method computationally efficient and straightforward to use. A series of numerical examples and experiments are provided to illustrate the working of the method.
Request-Based Mediated Execution
ERIC Educational Resources Information Center
Sundresh, Sameer
2009-01-01
How do you dynamically customize the programming language available in a context within an existing system, without changing the underlying system? This dissertation introduces a language design approach that addresses this problem. The basic idea is to structure programs as systems of multiple interacting levels of abstraction, where all of the…
Modeling Lolium perenne L. roots in the presence of empirical black holes
USDA-ARS?s Scientific Manuscript database
Plant root models are designed for understanding structural or functional aspects of root systems. When a process is not thoroughly understood, a black box object is used. However, when a process exists but empirical data do not indicate its existence, you have a black hole. The object of this re...
Exploration of tetrahedral structures in silicate cathodes using a motif-network scheme
Zhao, Xin; Wu, Shunqing; Lv, Xiaobao; ...
2015-10-26
Using a motif-network search scheme, we studied the tetrahedral structures of the dilithium/disodium transition metal orthosilicates A 2MSiO 4 with A = Li or Na and M = Mn, Fe or Co. In addition to finding all previously reported structures, we discovered many other different tetrahedral-network-based crystal structures which are highly degenerate in energy. In addition, these structures can be classified into structures with 1D, 2D and 3D M-Si-O frameworks. A clear trend of the structural preference in different systems was revealed and possible indicators that affect the structure stabilities were introduced. For the case of Na systems which havemore » been much less investigated in the literature relative to the Li systems, we predicted their ground state structures and found evidence for the existence of new structural motifs.« less
Observation of three-component fermions in the topological semimetal molybdenum phosphide.
Lv, B Q; Feng, Z-L; Xu, Q-N; Gao, X; Ma, J-Z; Kong, L-Y; Richard, P; Huang, Y-B; Strocov, V N; Fang, C; Weng, H-M; Shi, Y-G; Qian, T; Ding, H
2017-06-29
In quantum field theory, Lorentz invariance leads to three types of fermion-Dirac, Weyl and Majorana. Although the existence of Weyl and Majorana fermions as elementary particles in high-energy physics is debated, all three types of fermion have been proposed to exist as low-energy, long-wavelength quasiparticle excitations in condensed-matter systems. The existence of Dirac and Weyl fermions in condensed-matter systems has been confirmed experimentally, and that of Majorana fermions is supported by various experiments. However, in condensed-matter systems, fermions in crystals are constrained by the symmetries of the 230 crystal space groups rather than by Lorentz invariance, giving rise to the possibility of finding other types of fermionic excitation that have no counterparts in high-energy physics. Here we use angle-resolved photoemission spectroscopy to demonstrate the existence of a triply degenerate point in the electronic structure of crystalline molybdenum phosphide. Quasiparticle excitations near a triply degenerate point are three-component fermions, beyond the conventional Dirac-Weyl-Majorana classification, which attributes Dirac and Weyl fermions to four- and two-fold degenerate points, respectively. We also observe pairs of Weyl points in the bulk electronic structure of the crystal that coexist with the three-component fermions. This material thus represents a platform for studying the interplay between different types of fermions. Our experimental discovery opens up a way of exploring the new physics of unconventional fermions in condensed-matter systems.
Observation of three-component fermions in the topological semimetal molybdenum phosphide
NASA Astrophysics Data System (ADS)
Lv, B. Q.; Feng, Z.-L.; Xu, Q.-N.; Gao, X.; Ma, J.-Z.; Kong, L.-Y.; Richard, P.; Huang, Y.-B.; Strocov, V. N.; Fang, C.; Weng, H.-M.; Shi, Y.-G.; Qian, T.; Ding, H.
2017-06-01
In quantum field theory, Lorentz invariance leads to three types of fermion—Dirac, Weyl and Majorana. Although the existence of Weyl and Majorana fermions as elementary particles in high-energy physics is debated, all three types of fermion have been proposed to exist as low-energy, long-wavelength quasiparticle excitations in condensed-matter systems. The existence of Dirac and Weyl fermions in condensed-matter systems has been confirmed experimentally, and that of Majorana fermions is supported by various experiments. However, in condensed-matter systems, fermions in crystals are constrained by the symmetries of the 230 crystal space groups rather than by Lorentz invariance, giving rise to the possibility of finding other types of fermionic excitation that have no counterparts in high-energy physics. Here we use angle-resolved photoemission spectroscopy to demonstrate the existence of a triply degenerate point in the electronic structure of crystalline molybdenum phosphide. Quasiparticle excitations near a triply degenerate point are three-component fermions, beyond the conventional Dirac-Weyl-Majorana classification, which attributes Dirac and Weyl fermions to four- and two-fold degenerate points, respectively. We also observe pairs of Weyl points in the bulk electronic structure of the crystal that coexist with the three-component fermions. This material thus represents a platform for studying the interplay between different types of fermions. Our experimental discovery opens up a way of exploring the new physics of unconventional fermions in condensed-matter systems.
The Design of Distributed Micro Grid Energy Storage System
NASA Astrophysics Data System (ADS)
Liang, Ya-feng; Wang, Yan-ping
2018-03-01
Distributed micro-grid runs in island mode, the energy storage system is the core to maintain the micro-grid stable operation. For the problems that it is poor to adjust at work and easy to cause the volatility of micro-grid caused by the existing energy storage structure of fixed connection. In this paper, an array type energy storage structure is proposed, and the array type energy storage system structure and working principle are analyzed. Finally, the array type energy storage structure model is established based on MATLAB, the simulation results show that the array type energy storage system has great flexibility, which can maximize the utilization of energy storage system, guarantee the reliable operation of distributed micro-grid and achieve the function of peak clipping and valley filling.
Local atomic and magnetic structure of dilute magnetic semiconductor ( Ba , K ) ( Zn , Mn ) 2 As 2
Frandsen, Benjamin A.; Gong, Zizhou; Terban, Maxwell W.; ...
2016-09-06
We studied the atomic and magnetic structure of the dilute ferromagnetic semiconductor system (Ba,K)(Zn,Mn) 2As 2 through atomic and magnetic pair distribution function analysis of temperature-dependent x-ray and neutron total scattering data. Furthermore, we detected a change in curvature of the temperature-dependent unit cell volume of the average tetragonal crystallographic structure at a temperature coinciding with the onset of ferromagnetic order. We also observed the existence of a well-defined local orthorhombic structure on a short length scale of ≲5Å, resulting in a rather asymmetrical local environment of the Mn and As ions. Finally, the magnetic PDF revealed ferromagnetic alignment ofmore » Mn spins along the crystallographic c axis, with robust nearest-neighbor ferromagnetic correlations that exist even above the ferromagnetic ordering temperature. Finally, we discuss these results in the context of other experiments and theoretical studies on this system.« less
Assembly of hard spheres in a cylinder: a computational and experimental study.
Fu, Lin; Bian, Ce; Shields, C Wyatt; Cruz, Daniela F; López, Gabriel P; Charbonneau, Patrick
2017-05-14
Hard spheres are an important benchmark of our understanding of natural and synthetic systems. In this work, colloidal experiments and Monte Carlo simulations examine the equilibrium and out-of-equilibrium assembly of hard spheres of diameter σ within cylinders of diameter σ≤D≤ 2.82σ. Although phase transitions formally do not exist in such systems, marked structural crossovers can nonetheless be observed. Over this range of D, we find in simulations that structural crossovers echo the structural changes in the sequence of densest packings. We also observe that the out-of-equilibrium self-assembly depends on the compression rate. Slow compression approximates equilibrium results, while fast compression can skip intermediate structures. Crossovers for which no continuous line-slip exists are found to be dynamically unfavorable, which is the main source of this difference. Results from colloidal sedimentation experiments at low diffusion rate are found to be consistent with the results of fast compressions, as long as appropriate boundary conditions are used.
Does a network structure exist in molecular liquid SnI4 and GeI4?
NASA Astrophysics Data System (ADS)
Sakagami, Takahiro; Fuchizaki, Kazuhiro
2017-04-01
The existence of a network structure consisting of electrically neutral tetrahedral molecules in liquid SnI4 and GeI4 at ambient pressure was examined. The liquid structures employed for the examination were obtained from a reverse Monte Carlo analysis. The structures were physically interpreted by introducing an appropriate intermolecular interaction. A ‘bond’ was then defined as an intermolecular connection that minimizes the energy of intermolecular interaction. However, their ‘bond’ energy is too weak for the ‘bond’ and the resulting network structure to be defined statically. The vertex-to-edge orientation between the nearest molecules is so ubiquitous that almost all of the molecules in the system can take part in the network, which is reflected in the appearance of a prepeak in the structure factor.
Low-Mass Inflation Systems for Inflatable Structures
NASA Technical Reports Server (NTRS)
Thunnissen, Daniel P.; Webster, Mark S.; Engelbrecht, Carl S.
1995-01-01
The use of inflatable space structures has often been proposed for aerospace and planetary applications. Communication, power generation, and very-long-baseline interferometry are just three potential applications of inflatable technology. The success of inflatable structures depends on the development of an applications of inflatable technology. This paper describes two design studies performed to develop a low mass inflation system. The first study takes advantage of existing onboard propulsion gases to reduce the overall system mass. The second study assumes that there is no onboard propulsion system. Both studies employ advanced components developed for the Pluto fast flyby spacecraft to further reduce mass. The study examined four different types of systems: hydrazine, nitrogen and water, nitrogen, and xenon. This study shows that all of these systems can be built for a small space structure with masses lower than 0.5 kilograms.
Lagrangian Coherent Structures, Hyperbolicity, and Lyapunov Exponents
NASA Astrophysics Data System (ADS)
Haller, George
2010-05-01
We review the fundamental physical motivation behind the definition of Lagrangian Coherent Structures (LCS) and show how it leads to the concept of finite-time hyperbolicity in non-autonomous dynamical systems. Using this concept of hyperbolicity, we obtain a self-consistent criterion for the existence of attracting and repelling material surfaces in unsteady fluid flows, such as those in the atmosphere and the ocean. The existence of LCS is often postulated in terms of features of the Finite-Time Lyapunov Exponent (FTLE) field associated with the system. As simple examples show, however, the FTLE field does not necessarily highlight LCS, or may ighlight structures that are not LCS. Under appropriate nondegeneracy conditions, we show that ridges of the FTLE field indeed coincide with LCS in volume-preserving flows. For general flows, we obtain a more general scalar field whose ridges correspond to LCS. We finally review recent applications of LCS techniques to flight safety analysis at Hong Kong International Airport.
Biomedical and Catalytic Opportunities of Virus-Like Particles in Nanotechnology
Schwarz, B.; Uchida, M.; Douglas, T.
2016-01-01
Within biology, molecules are arranged in hierarchical structures that coordinate and control the many processes that allow for complex organisms to exist. Proteins and other functional macromolecules are often studied outside their natural nanostructural context because it remains difficult to create controlled arrangements of proteins at this size scale. Viruses are elegantly simple nanosystems that exist at the interface of living organisms and nonliving biological machines. Studied and viewed primarily as pathogens to be combatted, viruses have emerged as models of structural efficiency at the nanoscale and have spurred the development of biomimetic nanoparticle systems. Virus-like particles (VLPs) are noninfectious protein cages derived from viruses or other cage-forming systems. VLPs provide incredibly regular scaffolds for building at the nanoscale. Composed of self-assembling protein subunits, VLPs provide both a model for studying materials’ assembly at the nanoscale and useful building blocks for materials design. The robustness and degree of understanding of many VLP structures allow for the ready use of these systems as versatile nanoparticle platforms for the conjugation of active molecules or as scaffolds for the structural organization of chemical processes. Lastly the prevalence of viruses in all domains of life has led to unique activities of VLPs in biological systems most notably the immune system. Here we discuss recent efforts to apply VLPs in a wide variety of applications with the aim of highlighting how the common structural elements of VLPs have led to their emergence as paradigms for the understanding and design of biological nanomaterials. PMID:28057256
Systemic Operational Design: Improving Operational Planning for the Netherlands Armed Forces
2006-05-25
This methodology is called Soft Systems Methodology . His methodology is a structured way of thinking in which not only a perceived problematic...Many similarities exist between Systemic Operational Design and Soft Systems Methodology , their epistemology is related. Furthermore, they both have...Systems Thinking: Managing Chaos and Complexity. Boston: Butterworth Heinemann, 1999. Checkland, Peter, and Jim Scholes. Soft Systems Methodology in
Recent Developments in Smart Adaptive Structures for Solar Sailcraft
NASA Technical Reports Server (NTRS)
Whorton, M. S.; Kim, Y. K.; Oakley, J.; Adetona, O.; Keel, L. H.
2007-01-01
The "Smart Adaptive Structures for Solar Sailcraft" development activity at MSFC has investigated issues associated with understanding how to model and scale the subsystem and multi-body system dynamics of a gossamer solar sailcraft with the objective of designing sailcraft attitude control systems. This research and development activity addressed three key tasks that leveraged existing facilities and core competencies of MSFC to investigate dynamics and control issues of solar sails. Key aspects of this effort included modeling and testing of a 30 m deployable boom; modeling of the multi-body system dynamics of a gossamer sailcraft; investigation of control-structures interaction for gossamer sailcraft; and development and experimental demonstration of adaptive control technologies to mitigate control-structures interaction.
Functional evaluation of candidate ice structuring proteins using cell-free expression systems.
Brödel, A K; Raymond, J A; Duman, J G; Bier, F F; Kubick, S
2013-02-10
Ice structuring proteins (ISPs) protect organisms from damage or death by freezing. They depress the non-equilibrium freezing point of water and prevent recrystallization, probably by binding to the surface of ice crystals. Many ISPs have been described and it is likely that many more exist in nature that have not yet been identified. ISPs come in many forms and thus cannot be reliably identified by their structure or consensus ice-binding motifs. Recombinant protein expression is the gold standard for proving the activity of a candidate ISP. Among existing expression systems, cell-free protein expression is the simplest and gives the fastest access to the protein of interest, but selection of the appropriate cell-free expression system is crucial for functionality. Here we describe cell-free expression methods for three ISPs that differ widely in structure and glycosylation status from three organisms: a fish (Macrozoarces americanus), an insect (Dendroides canadensis) and an alga (Chlamydomonas sp. CCMP681). We use both prokaryotic and eukaryotic expression systems for the production of ISPs. An ice recrystallization inhibition assay is used to test functionality. The techniques described here should improve the success of cell-free expression of ISPs in future applications. Copyright © 2012 Elsevier B.V. All rights reserved.
Qualitative Fault Isolation of Hybrid Systems: A Structural Model Decomposition-Based Approach
NASA Technical Reports Server (NTRS)
Bregon, Anibal; Daigle, Matthew; Roychoudhury, Indranil
2016-01-01
Quick and robust fault diagnosis is critical to ensuring safe operation of complex engineering systems. A large number of techniques are available to provide fault diagnosis in systems with continuous dynamics. However, many systems in aerospace and industrial environments are best represented as hybrid systems that consist of discrete behavioral modes, each with its own continuous dynamics. These hybrid dynamics make the on-line fault diagnosis task computationally more complex due to the large number of possible system modes and the existence of autonomous mode transitions. This paper presents a qualitative fault isolation framework for hybrid systems based on structural model decomposition. The fault isolation is performed by analyzing the qualitative information of the residual deviations. However, in hybrid systems this process becomes complex due to possible existence of observation delays, which can cause observed deviations to be inconsistent with the expected deviations for the current mode in the system. The great advantage of structural model decomposition is that (i) it allows to design residuals that respond to only a subset of the faults, and (ii) every time a mode change occurs, only a subset of the residuals will need to be reconfigured, thus reducing the complexity of the reasoning process for isolation purposes. To demonstrate and test the validity of our approach, we use an electric circuit simulation as the case study.
1991-07-01
integrate -into the existing -structure and HVAC system. Costs-for a eutectic salt system are shown in Table 5 to compare with the DIS cooling systems. The... eutectic salt system is not an ice storage system, but is a phase change system that stores energy iniits heat of fusion and changes phase at 47 ’F
Probabilistic Structural Analysis Methods (PSAM) for Select Space Propulsion System Components
NASA Technical Reports Server (NTRS)
1999-01-01
Probabilistic Structural Analysis Methods (PSAM) are described for the probabilistic structural analysis of engine components for current and future space propulsion systems. Components for these systems are subjected to stochastic thermomechanical launch loads. Uncertainties or randomness also occurs in material properties, structural geometry, and boundary conditions. Material property stochasticity, such as in modulus of elasticity or yield strength, exists in every structure and is a consequence of variations in material composition and manufacturing processes. Procedures are outlined for computing the probabilistic structural response or reliability of the structural components. The response variables include static or dynamic deflections, strains, and stresses at one or several locations, natural frequencies, fatigue or creep life, etc. Sample cases illustrates how the PSAM methods and codes simulate input uncertainties and compute probabilistic response or reliability using a finite element model with probabilistic methods.
Optimal Harvesting in a Periodic Food Chain Model with Size Structures in Predators
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, Feng-Qin, E-mail: zhafq@263.net; Liu, Rong; Chen, Yuming, E-mail: ychen@wlu.ca
In this paper, we investigate a periodic food chain model with harvesting, where the predators have size structures and are described by first-order partial differential equations. First, we establish the existence of a unique non-negative solution by using the Banach fixed point theorem. Then, we provide optimality conditions by means of normal cone and adjoint system. Finally, we derive the existence of an optimal strategy by means of Ekeland’s variational principle. Here the objective functional represents the net economic benefit yielded from harvesting.
Code of Federal Regulations, 2011 CFR
2011-10-01
...— (1) Fire protection; (2) Structural integrity; (3) Electrical systems; (4) Plumbing; (5) Water treatment; (6) Waste disposal; and (7) Telecommunications networks. (c) Existing host nation facilities...
Code of Federal Regulations, 2013 CFR
2013-10-01
...— (1) Fire protection; (2) Structural integrity; (3) Electrical systems; (4) Plumbing; (5) Water treatment; (6) Waste disposal; and (7) Telecommunications networks. (c) Existing host nation facilities...
Code of Federal Regulations, 2014 CFR
2014-10-01
...— (1) Fire protection; (2) Structural integrity; (3) Electrical systems; (4) Plumbing; (5) Water treatment; (6) Waste disposal; and (7) Telecommunications networks. (c) Existing host nation facilities...
Code of Federal Regulations, 2012 CFR
2012-10-01
...— (1) Fire protection; (2) Structural integrity; (3) Electrical systems; (4) Plumbing; (5) Water treatment; (6) Waste disposal; and (7) Telecommunications networks. (c) Existing host nation facilities...
Using emergent order to shape a space society
NASA Technical Reports Server (NTRS)
Graps, Amara L.
1993-01-01
A fast-growing movement in the scientific community is reshaping the way that we view the world around us. The short-hand name for this movement is 'chaos'. Chaos is a science of the global, nonlinear nature of systems. The center of this set of ideas is that simple, deterministic systems can breed complexity. Systems as complex as the human body, ecology, the mind or a human society. While it is true that simple laws can breed complexity, the other side is that complex systems can breed order. It is the latter that I will focus on in this paper. In the past, nonlinear was nearly synonymous with unsolvable because no general analytic solutions exist. Mathematically, an essential difference exists between linear and nonlinear systems. For linear systems, you just break up the complicated system into many simple pieces and patch together the separated solutions for each piece to form a solution to the full problem. In contrast, solutions to a nonlinear system cannot be added to form a new solution. The system must be treated in its full complexity. While it is true that no general analytical approach exists for reducing a complex system such as a society, it can be modeled. The technical involves a mathematical construct called phase space. In this space stable structures can appear which I use as analogies for the stable structures that appear in a complex system such as an ecology, the mind or a society. The common denominator in all of these systems is that they rely on a process called feedback loops. Feedback loops link the microscopic (individual) parts to the macroscopic (global) parts. The key, then, in shaping a space society, is in effectively using feedback loops. This paper will illustrate how one can model a space society by using methods that chaoticists have developed over the last hundred years. And I will show that common threads exist in the modeling of biological, economical, philosophical, and sociological systems.
NASA Technical Reports Server (NTRS)
Abiteboul, Serge
1997-01-01
The amount of data of all kinds available electronically has increased dramatically in recent years. The data resides in different forms, ranging from unstructured data in the systems to highly structured in relational database systems. Data is accessible through a variety of interfaces including Web browsers, database query languages, application-specic interfaces, or data exchange formats. Some of this data is raw data, e.g., images or sound. Some of it has structure even if the structure is often implicit, and not as rigid or regular as that found in standard database systems. Sometimes the structure exists but has to be extracted from the data. Sometimes also it exists but we prefer to ignore it for certain purposes such as browsing. We call here semi-structured data this data that is (from a particular viewpoint) neither raw data nor strictly typed, i.e., not table-oriented as in a relational model or sorted-graph as in object databases. As will seen later when the notion of semi-structured data is more precisely de ned, the need for semi-structured data arises naturally in the context of data integration, even when the data sources are themselves well-structured. Although data integration is an old topic, the need to integrate a wider variety of data- formats (e.g., SGML or ASN.1 data) and data found on the Web has brought the topic of semi-structured data to the forefront of research. The main purpose of the paper is to isolate the essential aspects of semi- structured data. We also survey some proposals of models and query languages for semi-structured data. In particular, we consider recent works at Stanford U. and U. Penn on semi-structured data. In both cases, the motivation is found in the integration of heterogeneous data.
The Impact Of Middle Class Consumption On Democratization In Northeast Asia
2016-03-01
middle-class Koreans. This consumption disparity caused the structurally disadvantaged working-class Koreans to join national protests that ultimately...inequality and a mobility-restraining household registration system. There exists a key political tension around structurally disadvantaged Chinese migrant...lower middle-class Koreans. This consumption disparity caused the structurally disadvantaged working-class Koreans to join national protests that
Modeling Human-Computer Decision Making with Covariance Structure Analysis.
ERIC Educational Resources Information Center
Coovert, Michael D.; And Others
Arguing that sufficient theory exists about the interplay between human information processing, computer systems, and the demands of various tasks to construct useful theories of human-computer interaction, this study presents a structural model of human-computer interaction and reports the results of various statistical analyses of this model.…
Features and Historical Aspects of the Philippines Educational System
ERIC Educational Resources Information Center
Musa, Sajid; Ziatdinov, Rushan
2012-01-01
This article deals with the features of the Philippine educational system. Additionally, brief and concise information will be given on how the educational system came into existence, the organization and the structure of the system itself. This paper also tackles the obstacles and problems observed in the past and up to the present, and gives…
Towards an analytical theory of social change: the case of China.
Liu, Serena
2006-09-01
Lockwood argues that contradiction between the core institutional order and the material substructure of a society gives rise to potential social relationships which constitute a threat to the existing institutional order and may lead to change in the type of the society. Parkin, in particular, has advocated the application of the idea to the study of socialist societies. However, the situation of socialist China opposes Lockwood's view in that the new social relationships arising from the changing economic system do not pose a threat to the existing political system. Moreover, Lockwood underdevelops the connection between human action and social structure and does not theorize the mechanism linking system weakness and social change. This article formulates an alternative perspective by building on Giddens's structuration theory and Mouzelis's work on sociological theory. The theoretical framework is applied to China to give a flavour of how social change can be studied.
Sterrett-Hong, Emma M; Karam, Eli; Kiaer, Lynn
2017-09-01
Many community mental health (CMH) systems contain inefficiencies, contributing to unmet need for services among youth. Using a quasi-experimental research design, we examined the implementation of an adapted structural-strategic family intervention, Parenting with Love and Limits, in a state CMH system to increase efficiency of services to youth with co-existing internalizing and externalizing functional impairments (PLL n = 296; Treatment-As-Usual n = 296; 54% male; 81% Caucasian). Youth receiving PLL experienced shorter treatment durations and returned to CMH services at significantly lower rates than youth receiving treatment-as-usual. They also demonstrated significant decreases in internalizing and externalizing symptoms over time. Findings lay the foundation for further examination of the role of an adapted structural-strategic family treatment in increasing the efficiency of CMH systems.
An algebraic structure of discrete-time biaffine systems
NASA Technical Reports Server (NTRS)
Tarn, T.-J.; Nonoyama, S.
1979-01-01
New results on the realization of finite-dimensional, discrete-time, internally biaffine systems are presented in this paper. The external behavior of such systems is described by multiaffine functions and the state space is constructed via Nerode equivalence relations. We prove that the state space is an affine space. An algorithm which amounts to choosing a frame for the affine space is presented. Our algorithm reduces in the linear and bilinear case to a generalization of algorithms existing in the literature. Explicit existence criteria for span-canonical realizations as well as an affine isomorphism theorem are given.
Weight and structural analysis of four structural concepts for a land mobile satellite system
NASA Technical Reports Server (NTRS)
Ferebee, M. J.; Wright, R. L.; Farmer, J. T.
1982-01-01
The present study is concerned with a Land Mobile Satellite System (LMSS) which can provide mobile communications for commercial and government applications in nonmetropolitan areas of the continental U.S. and Canada as an augmentation to existing and planned terrestrial systems. The satellite system would provide 'narrow band' telecommunications services, thin-route fixed telephone and data services in the 806-890 MHz band, and continuous emergency beacon monitoring in the 406-406.1 MHz band. It is pointed out that a satellite system operating in concert with terrestrial cellular systems could provide truly ubiquitous mobile communications services in the U.S. and Canada. A single shuttle shuttle launch could place the LMSS spacecraft in geosynchronous orbit over the continental U.S. in 1995 with a 10-year lifetime. Attention is given to the structural concepts, a weight analysis, and a structural analysis.
A two-level structure for advanced space power system automation
NASA Technical Reports Server (NTRS)
Loparo, Kenneth A.; Chankong, Vira
1990-01-01
The tasks to be carried out during the three-year project period are: (1) performing extensive simulation using existing mathematical models to build a specific knowledge base of the operating characteristics of space power systems; (2) carrying out the necessary basic research on hierarchical control structures, real-time quantitative algorithms, and decision-theoretic procedures; (3) developing a two-level automation scheme for fault detection and diagnosis, maintenance and restoration scheduling, and load management; and (4) testing and demonstration. The outlines of the proposed system structure that served as a master plan for this project, work accomplished, concluding remarks, and ideas for future work are also addressed.
Spiegel, David S; Fortney, Jonathan J; Sotin, Christophe
2014-09-02
The hundreds of exoplanets that have been discovered in the past two decades offer a new perspective on planetary structure. Instead of being the archetypal examples of planets, those of our solar system are merely possible outcomes of planetary system formation and evolution, and conceivably not even especially common outcomes (although this remains an open question). Here, we review the diverse range of interior structures that are both known and speculated to exist in exoplanetary systems--from mostly degenerate objects that are more than 10× as massive as Jupiter, to intermediate-mass Neptune-like objects with large cores and moderate hydrogen/helium envelopes, to rocky objects with roughly the mass of Earth.
ERIC Educational Resources Information Center
Choe, Jong-Min; Lee, Jinjoo
1993-01-01
Reports on a study of accounting information systems that explored the interactions among influence factors (e.g., user participation in the development process, top management support, capability of information systems personnel, and existence of steering committees), contextual variables (e.g., organizational structure and task characteristics),…
Typologies in Comparative Vocational Education: Existing Models and a New Approach
ERIC Educational Resources Information Center
Pilz, Matthias
2016-01-01
The ways in which vocational education and training (VET) systems are structured vary significantly from country to country, both because different countries have different objectives for their VET systems and because VET is differently embedded within the education and labour market systems of any individual country. International research in…
Multidirectional four-dimensional shape measurement system
NASA Astrophysics Data System (ADS)
Lenar, Janusz; Sitnik, Robert; Witkowski, Marcin
2012-03-01
Currently, a lot of different scanning techniques are used for 3D imaging of human body. Most of existing systems are based on static registration of internal structures using MRI or CT techniques as well as 3D scanning of outer surface of human body by laser triangulation or structured light methods. On the other hand there is an existing mature 4D method based on tracking in time the position of retro-reflective markers attached to human body. There are two main drawbacks of this solution: markers are attached to skin (no real skeleton movement is registered) and it gives (x, y, z, t) coordinates only in those points (not for the whole surface). In this paper we present a novel multidirectional structured light measurement system that is capable of measuring 3D shape of human body surface with frequency reaching 60Hz. The developed system consists of two spectrally separated and hardware-synchronized 4D measurement heads. The principle of the measurement is based on single frame analysis. Projected frame is composed from sine-modulated intensity pattern and a special stripe allowing absolute phase measurement. Several different geometrical set-ups will be proposed depending on type of movements that are to be registered.
40 CFR 165.87 - Design and capacity requirements for existing structures.
Code of Federal Regulations, 2013 CFR
2013-07-01
... existing containment structure: (1) The containment structure must be constructed of steel, reinforced... existing structures. 165.87 Section 165.87 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Structures § 165.87 Design and capacity requirements for existing structures. (a) For all existing...
40 CFR 165.87 - Design and capacity requirements for existing structures.
Code of Federal Regulations, 2011 CFR
2011-07-01
... existing containment structure: (1) The containment structure must be constructed of steel, reinforced... existing structures. 165.87 Section 165.87 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Structures § 165.87 Design and capacity requirements for existing structures. (a) For all existing...
40 CFR 165.87 - Design and capacity requirements for existing structures.
Code of Federal Regulations, 2012 CFR
2012-07-01
... existing containment structure: (1) The containment structure must be constructed of steel, reinforced... existing structures. 165.87 Section 165.87 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Structures § 165.87 Design and capacity requirements for existing structures. (a) For all existing...
40 CFR 165.87 - Design and capacity requirements for existing structures.
Code of Federal Regulations, 2014 CFR
2014-07-01
... existing containment structure: (1) The containment structure must be constructed of steel, reinforced... existing structures. 165.87 Section 165.87 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Structures § 165.87 Design and capacity requirements for existing structures. (a) For all existing...
Structure of the thermodynamic arrow of time in classical and quantum theories
NASA Astrophysics Data System (ADS)
Korzekwa, Kamil
2017-05-01
In this work we analyze the structure of the thermodynamic arrow of time, defined by transformations that leave the thermal equilibrium state unchanged, in classical (incoherent) and quantum (coherent) regimes. We note that in the infinite-temperature limit, the thermodynamic ordering of states in both regimes exhibits a lattice structure. This means that when energy does not matter and the only thermodynamic resource is given by information, the thermodynamic arrow of time has a very specific structure. Namely, for any two states at present there exists a unique state in the past consistent with them and with all possible joint pasts. Similarly, there also exists a unique state in the future consistent with those states and with all possible joint futures. We also show that the lattice structure in the classical regime is broken at finite temperatures, i.e., when energy is a relevant thermodynamic resource. Surprisingly, however, we prove that in the simplest quantum scenario of a two-dimensional system, this structure is preserved at finite temperatures. We provide the physical interpretation of these results by introducing and analyzing the history erasure process, and point out that quantum coherence may be a necessary resource for the existence of an optimal erasure process.
A flexible telerobotic system for space operations
NASA Technical Reports Server (NTRS)
Sliwa, N. O.; Will, R. W.
1987-01-01
The objective and design of a proposed goal-oriented knowledge-based telerobotic system for space operations is described. This design effort encompasses the elements of the system executive and user interface and the distribution and general structure of the knowledge base, the displays, and the task sequencing. The objective of the design effort is to provide an expandable structure for a telerobotic system that provides cooperative interaction between the human operator and computer control. The initial phase of the implementation provides a rule-based, goal-oriented script generator to interface to the existing control modes of a telerobotic research system, in the Intelligent Systems Research Lab at NASA Research Center.
Pankavich, S; Ortoleva, P
2010-06-01
The multiscale approach to N-body systems is generalized to address the broad continuum of long time and length scales associated with collective behaviors. A technique is developed based on the concept of an uncountable set of time variables and of order parameters (OPs) specifying major features of the system. We adopt this perspective as a natural extension of the commonly used discrete set of time scales and OPs which is practical when only a few, widely separated scales exist. The existence of a gap in the spectrum of time scales for such a system (under quasiequilibrium conditions) is used to introduce a continuous scaling and perform a multiscale analysis of the Liouville equation. A functional-differential Smoluchowski equation is derived for the stochastic dynamics of the continuum of Fourier component OPs. A continuum of spatially nonlocal Langevin equations for the OPs is also derived. The theory is demonstrated via the analysis of structural transitions in a composite material, as occurs for viral capsids and molecular circuits.
Electrical and thermal investigations of the phase transition in sodium bicarbonate, NaHCO3
NASA Astrophysics Data System (ADS)
Abdel-Kader, M. M.; Fadly, M.; Abutaleb, M.; El-Tanahy, Z. H.; Eldehemy, K.; Ali, A. I.
1995-09-01
This paper reports on a structural phase transition in sodium hydrogen carbonate, NaHCO3 as revealed by the investigations of some electrical and thermal parameters. Measurements of d.c. electric conductivity (σ) and relative premittivity (epsilon) of polycrystalline samples of NaHCO3 as a function of temperature in the interval 300 < T < 400 K reveal the existence of a structural phase transition around 365 K. Differential thermal analysis (DTA) and thermogravimetric analysis (TGA) were also performed in the same temperature range. The (DTA) results confirm the existence of a structural phase transition at cong 365 K whereas the (TGA) results show the absence of any actual loss in weight in the transition temperature region. The data are correlated to the crystal structure including the hydrogen bonding system.
In-service health monitoring of composite structures
NASA Technical Reports Server (NTRS)
Pinto, Gino A.; Ventres, C. S.; Ginty, Carol A.; Chamis, Christos C.
1990-01-01
The aerospace industry is witnessing a vast utilization of composites in critical structural applications and anticipates even more use of them in future aircraft. Therefore, a definite need exists for a composite health monitoring expert system to meet today's current needs and tomorrow's future demands. The primary goal for this conceptual health monitoring system is functional reliably for in-service operation in the environments of various composite structures. The underlying philosophy of this system is to utilize proven vibration techniques to assess the structural integrity of a fibrous composite. Statistical methods are used to determine if the variances in the measured data are acceptable for making a reliable decision on the health status of the composite. The flexible system allows for algorithms describing any composite fatigue or damage behavior characteristic to be provided as an input to the system. Alert thresholds and variances can also be provided as an input to this system and may be updated to allow for future changes/refinements in the composite's structural integrity behavior.
Precast concrete pavement - systems and performance review
NASA Astrophysics Data System (ADS)
Novak, Josef; Kohoutková, Alena; Křístek, Vladimír; Vodička, Jan
2017-09-01
Long-term traffic restrictions belong to the key disadvantages of conventional cast-in-plane concrete pavements which have been used for technical structures such as roads, parking place and airfield pavements. As a consequence, the pressure is put on the development of such systems which have short construction time, low production costs, long-term durability, low maintenance requirements etc.. The paper presents the first step in the development of an entirely new precast concrete pavement (PCP) system applicable to airfield and highway pavements. The main objective of the review of PCP systems is to acquire a better understanding of the current systems and design methods used for transport infrastructure. There is lack of information on using PCP systems for the construction of entirely new pavements. To most extensive experience is dated back to the 20th century when hexagonal slab panels and system PAG were used in the Soviet Union for the military airfields. Since cast-in-situ pavements became more common, the systems based on precast concrete panels have been mainly utilized for the removal of damaged sections of existing structures including roads, highways etc.. Namely, it concerns Fort Miller Super Slab system, Michigan system, Uretek Stitch system and Kwik system. The presented review indicates several issues associated with the listed PCP systems and their applications to the repair and rehabilitation of existing structures. Among others, the type of manufacturing technology, particularly the position of slots for dowel bars, affects the durability and performance of the systems. Gathered information serve for the development of a new system for airfield and highway pavement construction.
[Study on structure and phase transformation laws of natural FeS2 whisker by Raman spectroscopy].
Huang, Fei; Kou, Da-Ming; Yao, Yu-Zeng; Ni, Pei; Ding, Jun-Ying
2009-08-01
FeS2 belongs to sulfide, including pyrite of isometric system and marcasite of orthorhombic system. The FeS2 discovered in Gengzhuang, Shanxi Province, was growing in the form of whisker. The study with scanning electron microscopy and electron probe show that the mineral components of FeS2 vary regularly. The structure of natural nano-micron FeS2 whisker was determined by micro-Raman spectroscopy. The results show that there exist two types of structure in FeS2 whiskers: pyrite and marcasite. Marcasite presents irregular shapes, such as coarse lotus root joints, crude columnar or beaded. Pyrite exists in the shape of straight line and smooth surface. In the early growing stage, Gengzhuang FeS2 whisker was mainly marcasite-type structure; in the middle stage it was coexistent structure of pyrite- and marcasite-type; in the late stage it was mainly pyrite-type. The growing stages of the whisker FeS2 show the phase transformation laws. Moreover, during the growing process marcasite was growing with pyrite coated on. Study on FeS2 whisker structure shows that there are correlations between phase transformation laws of the structure and forms, and between the forming time and the composition characteristics.
Structural integrity of wind tunnel wooden fan blades
NASA Technical Reports Server (NTRS)
Young, Clarence P., Jr.; Wingate, Robert T.; Rooker, James R.; Mort, Kenneth W.; Zager, Harold E.
1991-01-01
Information is presented which was compiled by the NASA Inter-Center Committee on Structural Integrity of Wooden Fan Blades and is intended for use as a guide in design, fabrication, evaluation, and assurance of fan systems using wooden blades. A risk assessment approach for existing NASA wind tunnels with wooden fan blades is provided. Also, state of the art information is provided for wooden fan blade design, drive system considerations, inspection and monitoring methods, and fan blade repair. Proposed research and development activities are discussed, and recommendations are provided which are aimed at future wooden fan blade design activities and safely maintaining existing NASA wind tunnel fan blades. Information is presented that will be of value to wooden fan blade designers, fabricators, inspectors, and wind tunnel operations personnel.
Data from clinical notes: a perspective on the tension between structure and flexible documentation
Denny, Joshua C; Xu, Hua; Lorenzi, Nancy; Stead, William W; Johnson, Kevin B
2011-01-01
Clinical documentation is central to patient care. The success of electronic health record system adoption may depend on how well such systems support clinical documentation. A major goal of integrating clinical documentation into electronic heath record systems is to generate reusable data. As a result, there has been an emphasis on deploying computer-based documentation systems that prioritize direct structured documentation. Research has demonstrated that healthcare providers value different factors when writing clinical notes, such as narrative expressivity, amenability to the existing workflow, and usability. The authors explore the tension between expressivity and structured clinical documentation, review methods for obtaining reusable data from clinical notes, and recommend that healthcare providers be able to choose how to document patient care based on workflow and note content needs. When reusable data are needed from notes, providers can use structured documentation or rely on post-hoc text processing to produce structured data, as appropriate. PMID:21233086
Topology synthesis and size optimization of morphing wing structures
NASA Astrophysics Data System (ADS)
Inoyama, Daisaku
This research demonstrates a novel topology and size optimization methodology for synthesis of distributed actuation systems with specific applications to morphing air vehicle structures. The main emphasis is placed on the topology and size optimization problem formulations and the development of computational modeling concepts. The analysis model is developed to meet several important criteria: It must allow a rigid-body displacement, as well as a variation in planform area, with minimum strain on structural members while retaining acceptable numerical stability for finite element analysis. Topology optimization is performed on a semi-ground structure with design variables that control the system configuration. In effect, the optimization process assigns morphing members as "soft" elements, non-morphing load-bearing members as "stiff' elements, and non-existent members as "voids." The optimization process also determines the optimum actuator placement, where each actuator is represented computationally by equal and opposite nodal forces with soft axial stiffness. In addition, the configuration of attachments that connect the morphing structure to a non-morphing structure is determined simultaneously. Several different optimization problem formulations are investigated to understand their potential benefits in solution quality, as well as meaningfulness of the formulations. Extensions and enhancements to the initial concept and problem formulations are made to accommodate multiple-configuration definitions. In addition, the principal issues on the external-load dependency and the reversibility of a design, as well as the appropriate selection of a reference configuration, are addressed in the research. The methodology to control actuator distributions and concentrations is also discussed. Finally, the strategy to transfer the topology solution to the sizing optimization is developed and cross-sectional areas of existent structural members are optimized under applied aerodynamic loads. That is, the optimization process is implemented in sequential order: The actuation system layout is first determined through multi-disciplinary topology optimization process, and then the thickness or cross-sectional area of each existent member is optimized under given constraints and boundary conditions. Sample problems are solved to demonstrate the potential capabilities of the presented methodology. The research demonstrates an innovative structural design procedure from a computational perspective and opens new insights into the potential design requirements and characteristics of morphing structures.
The Maker Movement, the Promise of Higher Education, and the Future of Work
ERIC Educational Resources Information Center
Wigner, Aubrey
2017-01-01
The 21st century will be the site of numerous changes in education systems in response to a rapidly evolving technological environment where existing skill sets and career structures may cease to exist or, at the very least, change dramatically. Likewise, the nature of work will also change to become more automated and more technologically…
Biomedical and Catalytic Opportunities of Virus-Like Particles in Nanotechnology.
Schwarz, B; Uchida, M; Douglas, T
2017-01-01
Within biology, molecules are arranged in hierarchical structures that coordinate and control the many processes that allow for complex organisms to exist. Proteins and other functional macromolecules are often studied outside their natural nanostructural context because it remains difficult to create controlled arrangements of proteins at this size scale. Viruses are elegantly simple nanosystems that exist at the interface of living organisms and nonliving biological machines. Studied and viewed primarily as pathogens to be combatted, viruses have emerged as models of structural efficiency at the nanoscale and have spurred the development of biomimetic nanoparticle systems. Virus-like particles (VLPs) are noninfectious protein cages derived from viruses or other cage-forming systems. VLPs provide incredibly regular scaffolds for building at the nanoscale. Composed of self-assembling protein subunits, VLPs provide both a model for studying materials' assembly at the nanoscale and useful building blocks for materials design. The robustness and degree of understanding of many VLP structures allow for the ready use of these systems as versatile nanoparticle platforms for the conjugation of active molecules or as scaffolds for the structural organization of chemical processes. Lastly the prevalence of viruses in all domains of life has led to unique activities of VLPs in biological systems most notably the immune system. Here we discuss recent efforts to apply VLPs in a wide variety of applications with the aim of highlighting how the common structural elements of VLPs have led to their emergence as paradigms for the understanding and design of biological nanomaterials. © 2017 Elsevier Inc. All rights reserved.
Workshop Organization and Management in Adult Education. Case Study of the MOBRAL System.
ERIC Educational Resources Information Center
da Costa, Lamartine Pereira
This case study of the organizational structure of the Brazilian Literacy Movement (MOBRAL) describes the various organizational changes made as the mediating agency attempted to develop a large-scale national program within the existing social structure. Steps in the organization's development are traced from: (1) Beginnings in 1970 under the…
ERIC Educational Resources Information Center
American Association of School Administrators, Washington, DC.
This paper is intended to assist school administrators in improving existing school organizations. It discusses the nature of organizations, provides indicators of reorganization timing, and discusses the task of reorganization. A matrix chart, used to analyze and compare different organizational structures, is provided with explanations.…
Biomedical Information Dissemination: Alternative Systems.
ERIC Educational Resources Information Center
Farquhar, J. A.
This memorandum is the result of an investigation into the three existing biomedical information services; MEDLARS (Medical Literature Analysis and Retrieval System), the interlibrary loan (ILL) service, and the network of Poison Control Centers. This research is intended to provide an understanding of the structure, quality, and coverage of these…
Payment Services for Global Online Systems Including Internet.
ERIC Educational Resources Information Center
Seebeck, Bill; And Others
1995-01-01
A panel of four conference presenters address issues related to paying for services provided through online systems. Discussion includes the following topics: metering devices; electronic/digital cash; working within existing banking/credit card structures; provision of payment mechanisms in countries without extensive credit card usage; and…
ERIC Educational Resources Information Center
Wurman, Richard Saul
Explored in this special issue of "Design Quarterly" are some of the existing data systems which describe, in visual terms, various urban entities: transportation systems, roadways, public buildings, land patterns, historical structures, as well as some new methods for developing physical information that will be widely used in the future. Through…
The US business cycle: power law scaling for interacting units with complex internal structure
NASA Astrophysics Data System (ADS)
Ormerod, Paul
2002-11-01
In the social sciences, there is increasing evidence of the existence of power law distributions. The distribution of recessions in capitalist economies has recently been shown to follow such a distribution. The preferred explanation for this is self-organised criticality. Gene Stanley and colleagues propose an alternative, namely that power law scaling can arise from the interplay between random multiplicative growth and the complex structure of the units composing the system. This paper offers a parsimonious model of the US business cycle based on similar principles. The business cycle, along with long-term growth, is one of the two features which distinguishes capitalism from all previously existing societies. Yet, economics lacks a satisfactory theory of the cycle. The source of cycles is posited in economic theory to be a series of random shocks which are external to the system. In this model, the cycle is an internal feature of the system, arising from the level of industrial concentration of the agents and the interactions between them. The model-in contrast to existing economic theories of the cycle-accounts for the key features of output growth in the US business cycle in the 20th century.
NASA Technical Reports Server (NTRS)
Watson, David; Knox, James C.; West, Phillip; Stanley, Christine M.; Bush, Richard
2015-01-01
The Life Support Systems Project (LSSP) under the Advanced Exploration Systems (AES) program builds upon the work performed under the AES Atmosphere Resource Recovery and Environmental Monitoring (ARREM) project focusing on the numerous technology development areas. The CO2 removal and associated air drying development efforts are focused on improving the current state-of-the-art system on the International Space Station (ISS) utilizing fixed beds of sorbent pellets by seeking more robust pelletized sorbents, evaluating structured sorbents, and examining alternate bed configurations to improve system efficiency and reliability. A component of the CO2 removal effort encompasses structural stability testing of existing and emerging sorbents. Testing will be performed on dry sorbents and sorbents that have been conditioned to three humidity levels. This paper describes the sorbent structural stability screening efforts in support of the LSS Project within the AES Program.
Structural Mineral Physics at Extreme Conditions
NASA Astrophysics Data System (ADS)
Chariton, S.; Dubrovinsky, L. S.; Dubrovinskaia, N.
2017-12-01
Laser heating techniques in diamond anvil cells (DACs) cover a wide pressure-temperature range - above 300 GPa and up to 5000 K. Recent advantages in on-line laser heating techniques resulted in a significant improvement of reliability of in situ X-ray powder diffraction studies in laser-heated DACs, which have become routine at a number of synchrotron facilities including specialized beam-lines at the 3rd generation synchrotrons. However, until recently, existing DAC laser-heating systems could not be used for structural X-ray diffraction studies aimed at structural refinements, i.e. measuring of the diffraction intensities, and not only at determining of lattice parameters. The reason is that in existing DAC laser-heating facilities the laser beam enters the cell at a fixed angle, and a partial rotation of the DAC, as required in monochromatic structural X-ray diffraction experiments, results in a loss of the target crystal and may be even dangerous if the powerful laser light starts to scatter in arbitrary directions by the diamond anvils. In order to overcome this problem we have develop a portable laser heating system and implement it at different diffraction beam lines. We demonstrate the application of this system for simultaneous high-pressure and high-temperature powder and single crystal diffraction studies using examples of studies of chemical and phase relations in the Fe-O system, transition metals carbonates, and silicate perovskites.
A programing system for research and applications in structural optimization
NASA Technical Reports Server (NTRS)
Sobieszczanski-Sobieski, J.; Rogers, J. L., Jr.
1981-01-01
The paper describes a computer programming system designed to be used for methodology research as well as applications in structural optimization. The flexibility necessary for such diverse utilizations is achieved by combining, in a modular manner, a state-of-the-art optimization program, a production level structural analysis program, and user supplied and problem dependent interface programs. Standard utility capabilities existing in modern computer operating systems are used to integrate these programs. This approach results in flexibility of the optimization procedure organization and versatility in the formulation of contraints and design variables. Features shown in numerical examples include: (1) variability of structural layout and overall shape geometry, (2) static strength and stiffness constraints, (3) local buckling failure, and (4) vibration constraints. The paper concludes with a review of the further development trends of this programing system.
An implementation of the programming structural synthesis system (PROSSS)
NASA Technical Reports Server (NTRS)
Rogers, J. L., Jr.; Sobieszczanski-Sobieski, J.; Bhat, R. B.
1981-01-01
A particular implementation of the programming structural synthesis system (PROSSS) is described. This software system combines a state of the art optimization program, a production level structural analysis program, and user supplied, problem dependent interface programs. These programs are combined using standard command language features existing in modern computer operating systems. PROSSS is explained in general with respect to this implementation along with the steps for the preparation of the programs and input data. Each component of the system is described in detail with annotated listings for clarification. The components include options, procedures, programs and subroutines, and data files as they pertain to this implementation. An example exercising each option in this implementation to allow the user to anticipate the type of results that might be expected is presented.
Carmack, Eddy; McLaughlin, Fiona; Whiteman, Gail; Homer-Dixon, Thomas
2012-02-01
It seems inevitable that the ongoing and rapid changes in the physical environment of the marine Arctic will push components of the region's existing social-ecological systems-small and large-beyond tipping points and into new regimes. Ongoing changes include warming, freshening, acidification, and alterations to food web structure. In anticipation we pose three distinct but interrelated challenges: (1) to explore existing connectivities within components of the marine system; (2) to seek indicators (if they exist) of approaching regime change through observation and modeling; and (3) to build functional resilience into existing systems through adaptation-oriented policy and to have in hand transformative options when tipping points are crossed and new development trajectories are required. Each of the above challenges is scale dependent, and each requires a much deeper understanding than we currently have of connectivity within existing systems and their response to external forcing. Here, we argue from a global perspective the need to understand the Arctic's role in an increasingly nonlinear world; then describe emerging evidence from new observations on the connectivity of processes and system components from the Canada Basin and subarctic seas surrounding northern North America; and finally posit an approach founded in "resilience thinking" to allow northern residents living in small coastal communities to participate in the observation, adaption and-if necessary-transformation of the social-ecological system with which they live.
[Classification of organisms and structuralism in biology].
Vasil'eva, L I
2001-01-01
Structuralism in biology is the oldest trend oriented to the search for natural "laws of forms" comparable with laws of growth of crystal, was revived at the end of 20th century on the basis of structuralist thought in socio-humanitarian sciences. The development of principal ideas of the linguistic structuralism in some aspects is similar to that of biological systematics, especially concerning the relationships between "system" and "evolution". However, apart from this general similarity, biological structuralism is strongly focused on familiar problems of the origin of diversity in nature. In their striving for the renovation of existing views, biological structuralists oppose the neo-darwinism emphasizing the existence of "law of forms", that are independent on heredity and genetic "determinism". The trend to develop so-called "rational taxonomy" is also characteristic of biological structuralism but this attempt failed being connected neither with Darwin's historicism nor with Plato's typology.
[Organizational forms of emergency medicine in international comparison].
Lipp, M
1993-09-01
The tasks of preclinical emergency medicine systems (PEMS) are to stabilize and maintain the vital functions and to guarantee qualified transport to the hospital. Worldwide, different structures exist as a result of historical developments. Legal regulations for PEMS have been introduced in most of the industrialized countries since 1960. More and more aspects have been subject to detailed regulations. PEMS are provided either by state-owned or by state-controlled (private) organisations. In most of the "underdeveloped" countries legal regulations do not exist and PEMS is often provided by social workers, by the army or by volunteers. In most countries, PEMS are financed by the state with a charge on the patient. In a few states PEMS are totally financed by the public health structure. Modern PEMS are controlled from dispatch centres which receive emergency calls (mostly by telephone) and send the appropriate rescue unit. In most states the staff of dispatch centres are paramedics; in some countries and in some urban areas physicians control the dispatch centre. In PEMS without physicians on the scene, an information exchange between the scene and the hospital can be observed frequently, in contrast to systems with physicians on the scene. Worldwide, ground-based PEMS are preferred, but in most countries an additional air rescue system has been established. The quality and quantity of the technical equipment of the ground-based PEMS differ widely: nationwide regulations exist, however, in the USA and Germany. Generally, there are two main concepts concerning the personnel structure: PEMS are either physician based or not. Requirements for emergency physicians differ greatly: in some countries no formal requirements exist, in others extensive practical and theoretical training is required.(ABSTRACT TRUNCATED AT 250 WORDS)
State-Level High School Improvement Systems Checklist
ERIC Educational Resources Information Center
National High School Center, 2007
2007-01-01
This checklist is designed to help states at various stages develop their system of support to reach struggling high schools. The checklist can be used to assess where your state is in terms of the elements of using existing support and guidance mechanisms, and reconfiguring and/or creating new structures to leverage system change for high school…
Consumer Trust in the U.S. Food System: An Examination of the Recreancy Theorem
ERIC Educational Resources Information Center
Sapp, Stephen G.; Arnot, Charlie; Fallon, James; Fleck, Terry; Soorholtz, David; Sutton-Vermeulen, Matt; Wilson, Jannette J. H.
2009-01-01
Because consumer opinions to an increasing extent affect the structure and management of the U.S. food system, it is important for social scientists to accurately model consumer trust in this system so they can better understand and anticipate public responses to existing or proposed food-related regulatory policies and facilitate effective…
An Expert Assistant for Computer Aided Parallelization
NASA Technical Reports Server (NTRS)
Jost, Gabriele; Chun, Robert; Jin, Haoqiang; Labarta, Jesus; Gimenez, Judit
2004-01-01
The prototype implementation of an expert system was developed to assist the user in the computer aided parallelization process. The system interfaces to tools for automatic parallelization and performance analysis. By fusing static program structure information and dynamic performance analysis data the expert system can help the user to filter, correlate, and interpret the data gathered by the existing tools. Sections of the code that show poor performance and require further attention are rapidly identified and suggestions for improvements are presented to the user. In this paper we describe the components of the expert system and discuss its interface to the existing tools. We present a case study to demonstrate the successful use in full scale scientific applications.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mandara, A.; Ramundo, F.; Spina, G.
2008-07-08
The first part of a study concerning innovative intervention techniques for dissipate a share of the input seismic energy compatible with the preservation of existing buildings, including historical and monumental constructions, is presented in this paper. The case of a typical scheme of a long-bay box-like masonry building fitted with a dissipative floating roof is analyzed. In the examined building a wide simulation analysis has shown the achievement of a very satisfying performance. Furthermore, the effectiveness of the system can be maximized by means of active or semi-active devices implemented in the floating roof and a significant reduction of themore » seismic impact on the building can be obtained compared with non-controlled or simply passively controlled structure. The results prove the remarkable increase of the energy dissipation capability of the system, as well as the reduction of structural damage, independently of any specific strengthening intervention.« less
An investigation on wireless sensors for asset management and health monitoring of civil structures
NASA Astrophysics Data System (ADS)
Furkan, Mustafa; Mao, Qiang; Mazzotti, Matteo; DeVitis, John; Sumitro, S. Paul; Faridazar, Fred; Aktan, A. Emin; Moon, Franklin; Bartoli, Ivan
2016-04-01
Application of wireless sensors and sensor networks for Structural Health Monitoring has been investigated for a long time. Key limitations for practical use are energy requirements, connectivity, and integration with existing systems. Current sensors and sensor networks mainly rely on wired connectivity for communication and external power source for energy. This paper presents a suite of wireless sensors that are low-cost, maintenance free, rugged, and have long service life. The majority of the sensors considered were designed by transforming existing, proven, and robust wired sensors into wireless units. In this study, the wireless sensors were tested in laboratory conditions for calibration and evaluation along with wired sensors. The experimental results were also compared to theoretical results. The tests mostly show satisfactory performance of the wireless units. This work is part of a broader Federal Highway Administration sponsored project intended to ultimately validate a wireless sensing system on a real, operating structure to account for all the uncertainties, environmental conditions and operational variability that are encountered in the field.
From Bridges and Rockets, Lessons for Software Systems
NASA Technical Reports Server (NTRS)
Holloway, C. Michael
2004-01-01
Although differences exist between building software systems and building physical structures such as bridges and rockets, enough similarities exist that software engineers can learn lessons from failures in traditional engineering disciplines. This paper draws lessons from two well-known failures the collapse of the Tacoma Narrows Bridge in 1940 and the destruction of the space shuttle Challenger in 1986 and applies these lessons to software system development. The following specific applications are made: (1) the verification and validation of a software system should not be based on a single method, or a single style of methods; (2) the tendency to embrace the latest fad should be overcome; and (3) the introduction of software control into safety-critical systems should be done cautiously.
Evaluation of a data dictionary system. [information dissemination and computer systems programs
NASA Technical Reports Server (NTRS)
Driggers, W. G.
1975-01-01
The usefulness was investigated of a data dictionary/directory system for achieving optimum benefits from existing and planned investments in computer data files in the Data Systems Development Branch and the Institutional Data Systems Division. Potential applications of the data catalogue system are discussed along with an evaluation of the system. Other topics discussed include data description, data structure, programming aids, programming languages, program networks, and test data.
Formulation of human-structure interaction system models for vertical vibration
NASA Astrophysics Data System (ADS)
Caprani, Colin C.; Ahmadi, Ehsan
2016-09-01
In this paper, human-structure interaction system models for vibration in the vertical direction are considered. This work assembles various moving load models from the literature and proposes extension of the single pedestrian to a crowd of pedestrians for the FE formulation for crowd-structure interaction systems. The walking pedestrian vertical force is represented as a general time-dependent force, and the pedestrian is in turn modelled as moving force, moving mass, and moving spring-mass-damper. The arbitrary beam structure is modelled using either a formulation in modal coordinates or finite elements. In each case, the human-structure interaction (HSI) system is first formulated for a single walking pedestrian and then extended to consider a crowd of pedestrians. Finally, example applications for single pedestrian and crowd loading scenarios are examined. It is shown how the models can be used to quantify the interaction between the crowd and bridge structure. This work should find use for the evaluation of existing and new footbridges.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-11
...-4] RIN 2040-AE95 National Pollutant Discharge Elimination System--Proposed Regulations to Establish Requirements for Cooling Water Intake Structures at Existing Facilities; Notice of Data Availability Related to... Data Availability. SUMMARY: On April 20, 2011, EPA published proposed standards for cooling water...
DOT National Transportation Integrated Search
2012-06-01
This project evaluates the physical and economic feasibility of using existing traffic infrastructure to mount wind power : generators. Some possible places to mount a light weight wind generator and solar panel hybrid system are: i) Traffic : signal...
Integrated reclamation: Approaching ecological function?
Ann L. Hild; Nancy L. Shaw; Ginger B. Paige
2009-01-01
Attempts to reclaim arid and semiarid lands have traditionally targeted plant species composition. Much research attention has been directed to seeding rates, species mixes and timing of seeding. However, in order to attain functioning systems, attention to structure and process must compliment existing efforts. We ask how to use a systems approach to enhance...
Verification of Modelica-Based Models with Analytical Solutions for Tritium Diffusion
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rader, Jordan D.; Greenwood, Michael Scott; Humrickhouse, Paul W.
Here, tritium transport in metal and molten salt fluids combined with diffusion through high-temperature structural materials is an important phenomenon in both magnetic confinement fusion (MCF) and molten salt reactor (MSR) applications. For MCF, tritium is desirable to capture for fusion fuel. For MSRs, uncaptured tritium potentially can be released to the environment. In either application, quantifying the time- and space-dependent tritium concentration in the working fluid(s) and structural components is necessary.Whereas capability exists specifically for calculating tritium transport in such systems (e.g., using TMAP for fusion reactors), it is desirable to unify the calculation of tritium transport with othermore » system variables such as dynamic fluid and structure temperature combined with control systems such as those that might be found in a system code. Some capability for radioactive trace substance transport exists in thermal-hydraulic systems codes (e.g., RELAP5-3D); however, this capability is not coupled to species diffusion through solids. Combined calculations of tritium transport and thermal-hydraulic solution have been demonstrated with TRIDENT but only for a specific type of MSR.Researchers at Oak Ridge National Laboratory have developed a set of Modelica-based dynamic system modeling tools called TRANsient Simulation Framework Of Reconfigurable Models (TRANSFORM) that were used previously to model advanced fission reactors and associated systems. In this system, the augmented TRANSFORM library includes dynamically coupled fluid and solid trace substance transport and diffusion. Results from simulations are compared against analytical solutions for verification.« less
Verification of Modelica-Based Models with Analytical Solutions for Tritium Diffusion
Rader, Jordan D.; Greenwood, Michael Scott; Humrickhouse, Paul W.
2018-03-20
Here, tritium transport in metal and molten salt fluids combined with diffusion through high-temperature structural materials is an important phenomenon in both magnetic confinement fusion (MCF) and molten salt reactor (MSR) applications. For MCF, tritium is desirable to capture for fusion fuel. For MSRs, uncaptured tritium potentially can be released to the environment. In either application, quantifying the time- and space-dependent tritium concentration in the working fluid(s) and structural components is necessary.Whereas capability exists specifically for calculating tritium transport in such systems (e.g., using TMAP for fusion reactors), it is desirable to unify the calculation of tritium transport with othermore » system variables such as dynamic fluid and structure temperature combined with control systems such as those that might be found in a system code. Some capability for radioactive trace substance transport exists in thermal-hydraulic systems codes (e.g., RELAP5-3D); however, this capability is not coupled to species diffusion through solids. Combined calculations of tritium transport and thermal-hydraulic solution have been demonstrated with TRIDENT but only for a specific type of MSR.Researchers at Oak Ridge National Laboratory have developed a set of Modelica-based dynamic system modeling tools called TRANsient Simulation Framework Of Reconfigurable Models (TRANSFORM) that were used previously to model advanced fission reactors and associated systems. In this system, the augmented TRANSFORM library includes dynamically coupled fluid and solid trace substance transport and diffusion. Results from simulations are compared against analytical solutions for verification.« less
Non-cooperative Fisher-KPP systems: traveling waves and long-time behavior
NASA Astrophysics Data System (ADS)
Girardin, Léo
2018-01-01
This paper is concerned with non-cooperative parabolic reaction-diffusion systems which share structural similarities with the scalar Fisher-KPP equation. These similarities make it possible to prove, among other results, an extinction and persistence dichotomy and, when persistence occurs, the existence of a positive steady state, the existence of traveling waves with a half-line of possible speeds and a positive minimal speed and the equality between this minimal speed and the spreading speed for the Cauchy problem. Non-cooperative KPP systems can model various phenomena where the following three mechanisms occur: local diffusion in space, linear cooperation and superlinear competition.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Egorysheva, A.V., E-mail: anna_egorysheva@rambler.ru; Ellert, O.G.; Gajtko, O.M.
2015-05-15
The refinement of the Bi{sub 2}O{sub 3}–Fe{sub 2}O{sub 3}–Sb{sub 2}O{sub 5} system phase diagram has been performed and the existence of the two ternary compounds has been confirmed. The first one with a pyrochlore-type structure (sp. gr. Fd 3-barm) exists in the wide solid solution region, (Bi{sub 2−x}Fe{sub x})Fe{sub 1+y}Sb{sub 1−y}O{sub 7±δ}, where x=0.1–0.4 and y=−0.13–0.11. The second one, Bi{sub 3}FeSb{sub 2}O{sub 11}, corresponds to the cubic KSbO{sub 3}-type structure (sp. gr. Pn 3-bar) with unit cell parameter a=9.51521(2) Å. The Rietveld structure refinement showed that this compound is characterized by disordered structure. The Bi{sub 3}FeSb{sub 2}O{sub 11} factor groupmore » analysis has been carried out and a Raman spectrum has been investigated. According to magnetization measurements performed at the temperature range 2–300 K it may be concluded that the Bi{sub 3}FeSb{sub 2}O{sub 11} magnetic properties can be substantially described as a superposition of strong short-range antiferromagnetic exchange interactions realizing inside the [(FeSb{sub 2})O{sub 9}] 3D-framework via different pathways. - Graphical abstract: The refinement of the Bi{sub 2}O{sub 3}–Fe{sub 2}O{sub 3}–Sb{sub 2}O{sub 5} system phase diagram has been performed and the existence of the solid solution with a pyrochlore-type structure (sp. gr. Fd 3-barm) and Bi{sub 3}FeSb{sub 2}O{sub 11}, correspond of the cubic KSbO{sub 3}-type structure (sp. gr. Pn 3-bar has been confirmed. The structure refinement, Raman spectroscopy as well as magnetic measurements data of Bi{sub 3}FeSb{sub 2}O{sub 11} are presented. - Highlights: • The Bi{sub 2}O{sub 3}–Fe{sub 2}O{sub 3}–Sb{sub 2}O{sub 5} system phase diagram refinement has been performed. • The Bi{sub 3}FeSb{sub 2}O{sub 11} existence along with pyrochlore structure compound is shown. • It was determined that the Bi{sub 3}FeSb{sub 2}O{sub 11} is of disordered cubic KSbO{sub 3}-type structure. • Factor group analysis of Bi{sub 3}FeSb{sub 2}O{sub 11} vibrational spectrum has been performed. • Short-range antiferromagnetic interactions govern Bi{sub 3}FeSb{sub 2}O{sub 11} magnetic behavior.« less
On the existence of point spectrum for branching strips quantum graph
DOE Office of Scientific and Technical Information (OSTI.GOV)
Popov, I. Yu., E-mail: popov1955@gmail.com; Skorynina, A. N.; Blinova, I. V., E-mail: irin-a@yandex.ru
2014-03-15
The quantum graph having the form of branching strips with hexagonal (honeycomb) structure is considered. The Hamiltonian is determined as free 1D Schrödinger operator on each edge and some “boundary” conditions at each vertex. We obtain the conditions ensuring the point spectrum's existence for the Schrödinger operator of the system and relations that give us the eigenvalues.
Research of a real-time overload monitoring and response system of bridges and roads
NASA Astrophysics Data System (ADS)
Yu, Yan; Shi, Yan; Zhao, Xuefeng; Ou, Jinping
2012-04-01
Due to the general overloading of vehicles, premature failure of bridges and roads are more and more obvious. Structural behaviors of engineering structures need real-time monitoring and diagnosis, timely detection of structural damage, evaluation of their safety, and necessary precautions, in order to prevent major accident such as the collapse of bridges and roads. But the existing monitoring system, which is very expensive, does not apply to the low budget structures. Therefore, a potable, low-cost, low-power structural monitoring system, which consists of electric resistance strain gauge, collection and execution unit, graph collection system and analysis software, is designed in this paper. The system can collect the critical data about the force of pavement to take the certain judge algorithm. The alarm will be given and the overburden data will be transmitted to IDC to make the further analysis when the pavement is overburden. At the same time, the plates of overweight vehicles can be collected and sent to the relevant departments. The system has the features of simple structure, easy realization, and low cost, which fills the application gaps in structural health monitoring of low-budget project.
Performance of FRCM strengthened beams subject to fatigue.
DOT National Transportation Integrated Search
2017-05-31
Fabric Reinforced Cementitious Matrix (FRCM) systems have been developed to strengthen or rehabilitate existing concrete and masonry structures subject to damage, steel reinforcement corrosion or requiring resistance capacity improvements due to incr...
Application of fiber-reinforced bismaleimide materials to aircraft nacelle structures
NASA Technical Reports Server (NTRS)
Peros, Vasilios; Ruth, John; Trawinski, David
1992-01-01
Existing aircraft engine nacelle structures employ advanced composite materials to reduce weight and thereby increase overall performance. Use of advanced composite materials on existing aircraft nacelle structures includes fiber-reinforced epoxy structures and has typically been limited to regions furthest away from the hot engine core. Portions of the nacelle structure that are closer to the engine require materials with a higher temperature capability. In these portions, existing nacelle structures employ aluminum sandwich construction and skin/stringer construction. The aluminum structure is composed of many detail parts and assemblies and is usually protected by some form of ablative, insulator, or metallic thermal shield. A one-piece composite inner cowl for a new-generation engine nacelle structure has been designed using fiber-reinforced bismaleimide (BMI) materials and honeycomb core in a sandwich construction. The new composite design has many advantages over the existing aluminum structure. Multiple details were integrated into the one-piece composite design, thereby significantly reducing the number of detail parts and fasteners. The use of lightweight materials and the reduction of the number of joints result in a significant weight reduction over the aluminum design; manufacturing labor and the overall number of tools required have also been reduced. Several significant technical issues were addressed in the development of a BMI composite design. Technical evaluation of the available BMI systems led to the selection of a toughened BMI material which was resistant to microcracking under thermal cyclic loading and enhanced the damage tolerance of the structure. Technical evaluation of the degradation of BMI materials in contact with aluminum and other metals validated methods for isolation of the various materials. Graphite-reinforced BMI in contact with aluminum and some steels was found to degrade in salt spray testing. Isolation techniques such as those used for graphite-reinforced epoxy structures were shown to provide adequate protection. The springback and producibility of large BMI structures were evaluated by manufacturing prototype hardware which had the full-scale cross section of the one-piece composite structure.
Magnetic properties in polycrystalline and single crystal Ca-doped LaCoO3
NASA Astrophysics Data System (ADS)
Zeng, R.; Debnath, J. C.; Chen, D. P.; Shamba, P.; Wang, J. L.; Kennedy, S. J.; Campbell, S. J.; Silver, T.; Dou, S. X.
2011-04-01
Polycrystalline (PC) and single crystalline (SC) Ca-doped LaCoO3 (LCCO) samples with the perovskite structure were synthesized by conventional solid-state reaction and the floating-zone growth method. We present the results of a comprehensive investigation of the magnetic properties of the LCCO system. Systematic measurements have been conducted on dc magnetization, ac susceptibility, exchange-bias, and the magnetocaloric effect. These findings suggest that complex structural phases, ferromagnetic (FM), and spin-glass/cluster-spin-glass (CSG), and their transitions exist in PC samples, while there is a much simpler magnetic phase in SC samples. It was also of interest to discover that the CSG induced a magnetic field memory effect and an exchange-bias-like effect, and that a large inverse irreversible magnetocaloric effect exists in this system.
ERIC Educational Resources Information Center
Palme, Jacob
The four papers contained in this document provide: (1) a survey of computer based mail and conference systems; (2) an evaluation of systems for both individually addressed mail and group addressing through conferences and distribution lists; (3) a discussion of various methods of structuring the text data in existing systems; and (4) a…
Documentation of structures branch programs and program updates. Project 3200
NASA Technical Reports Server (NTRS)
Probe, D. G.
1975-01-01
Update programming of applications programs for the integrated structural analysis system is reported. An attempt is made to layout a standard document format for the preparation of program documents. Documentation which involves changes, additions, and I/O capability revisions to existing programs includes a checklist which should be reviewed each time a programming effort is documented.
Program Costing with the CAMPUS Simulation Model. Project PRIME Report, Number 5.
ERIC Educational Resources Information Center
Cordes, David C.
The first section of this report on program costing with the CAMPUS simulation discusses the structuring process of Program Planning and Budgeting (PPB) systems, and emphasizes the ideas, rules, and principles for structuring resource data that have evolved during the 10 years of PPB existence. It also discusses the WICHE-PMS program…
ERIC Educational Resources Information Center
Jameson-Meledy, Kathryn
2013-01-01
The purpose of this research was to compare the differing structures of governance within the California Community College (CCC) system in relation to resource development and grant management. This is to explain how governance may impact the effectiveness of institutions to strengthen services to students with funding resources secured through…
Behavior-Based Multi-Robot Collaboration for Autonomous Construction Tasks
NASA Technical Reports Server (NTRS)
Stroupe, Ashley; Huntsberger, Terry; Okon, Avi; Aghazarian, Hrand; Robinson, Matthew
2005-01-01
We present a heterogeneous multi-robot system for autonomous construction of a structure through assembly of long components. Placement of a component within an existing structure in a realistic environment is demonstrated on a two-robot team. The task requires component acquisition, cooperative transport, and cooperative precision manipulation. Far adaptability, the system is designed as a behavior-based architecture. Far applicability to space-related construction efforts, computation, power, communication, and sensing are minimized, though the techniques developed are also applicable to terrestrial construction tasks.
Reid, B L
1995-06-01
The argument is developed that a structure and function already exists in selected inanimate systems for an intangible energy dissipating these systems and that, in so doing, this energy exhibits certain properties, readily recognised in the functioning biosystem. The central thesis is that, during dissipation, the structure of the biosystem affords opportunity for an enhanced display of these properties, so that this structure can be rationally recognised as obligatory in the transition, inanimate to animate matter. The systems chosen are those of reactance in linear circuit theory of electronics, and some recent developments in non-linear optics, both of which rely on imaginary or quantal force to display observable effects. Discussion occurs on the fashion which the development of a statistical formalism as a basis for the study of squeezed states of light in these non-linear systems, has, at the same time, overcome a long standing veto on the practical use of quantal energy associated with the Uncertainty Principle of Heisenberg. These ideas are used to vindicate the suggestion that a theoretical basis is presently available for an engineering type approach, toward an intangible force as it exists in the biosystem. The origins and properties of such a force continue to be considered by many as immersed in mysticism.
NASA Astrophysics Data System (ADS)
Masood, W.; Zahoor, Sara; Gul-e-Ali, Ahmad, Ali
2016-09-01
Nonlinear dissipative structures are studied in one and two dimensions in nonuniform magnetized plasmas with non-Maxwellian electrons. The dissipation is incorporated in the system through ion-neutral collisions. Employing the drift approximation, nonlinear drift waves are derived in 1D, whereas coupled drift-ion acoustic waves are derived in 2D in the weak nonlinearity limit. It is found that the ratio of the diamagnetic drift velocity to the velocity of nonlinear structure determines the nature (compressive or rarefactive) of the shock structure. The upper and lower bounds for velocity of the nonlinear shock structures are also found. It is noticed that the existence regimes for the drift shock waves in one and two dimensions for Cairns distributed electrons are very distinct from those with kappa distributed electrons. Interestingly, it is found that both compressive and rarefactive shock structures could be obtained for the one dimensional drift waves with kappa distributed electrons.
1981-11-01
34Structural Analysis of Concrete Pavement Systems," Journal, ASCE, Vol. 106, No. TE5, September 1980. 6. Barenberg, E. J., and Arntzen , D. M., "Design of...International Airport," Unpublished Report, Consultant Brandley to SEA-TAC Airport Authority, December 1971. 8. Personal Observation by Author. 9. Arntzen , D
Photonic structures in biology
NASA Astrophysics Data System (ADS)
Vukusic, Pete; Sambles, J. Roy
2003-08-01
Millions of years before we began to manipulate the flow of light using synthetic structures, biological systems were using nanometre-scale architectures to produce striking optical effects. An astonishing variety of natural photonic structures exists: a species of Brittlestar uses photonic elements composed of calcite to collect light, Morpho butterflies use multiple layers of cuticle and air to produce their striking blue colour and some insects use arrays of elements, known as nipple arrays, to reduce reflectivity in their compound eyes. Natural photonic structures are providing inspiration for technological applications.
Candidate Mission from Planet Earth control and data delivery system architecture
NASA Technical Reports Server (NTRS)
Shapiro, Phillip; Weinstein, Frank C.; Hei, Donald J., Jr.; Todd, Jacqueline
1992-01-01
Using a structured, experienced-based approach, Goddard Space Flight Center (GSFC) has assessed the generic functional requirements for a lunar mission control and data delivery (CDD) system. This analysis was based on lunar mission requirements outlined in GSFC-developed user traffic models. The CDD system will facilitate data transportation among user elements, element operations, and user teams by providing functions such as data management, fault isolation, fault correction, and link acquisition. The CDD system for the lunar missions must not only satisfy lunar requirements but also facilitate and provide early development of data system technologies for Mars. Reuse and evolution of existing data systems can help to maximize system reliability and minimize cost. This paper presents a set of existing and currently planned NASA data systems that provide the basic functionality. Reuse of such systems can have an impact on mission design and significantly reduce CDD and other system development costs.
NASA Astrophysics Data System (ADS)
Shao, Weber; Kupelian, Patrick A.; Wang, Jason; Low, Daniel A.; Ruan, Dan
2014-03-01
We devise a paradigm for representing the DICOM-RT structure sets in a database management system, in such way that secondary calculations of geometric information can be performed quickly from the existing contour definitions. The implementation of this paradigm is achieved using the PostgreSQL database system and the PostGIS extension, a geographic information system commonly used for encoding geographical map data. The proposed paradigm eliminates the overhead of retrieving large data records from the database, as well as the need to implement various numerical and data parsing routines, when additional information related to the geometry of the anatomy is desired.
Rozhkov, S P
2005-01-01
Equations of spinodal and two quasispinodals corresponding to critical and supercritical phase transitions leading to a rise of different dynamic structures of solution in the phase diagram of a model system water-biopolymer-electrolyte were obtained. The section of the phase diagram was considered where there exists the probability of quasi-equilibrium monomer-cluster and the principle of water-ion homeostasis is realized. Based on these results, a possible mechanism of origination of unspecific adaptation reactions of a biomolecular system at the stage of chemical evolution was suggested.
Machine & electrical double control air dryer for vehicle air braking system
NASA Astrophysics Data System (ADS)
Zhang, Xuan; Yang, Liu; Wang, Xian Yan; Tan, Xiao Yan; Wang, Wei
2017-09-01
As is known to all, a vehicle air brake system, in which usually contains moisture. To solve the problem, it is common to use air dryer to dry compressed air effectively and completely remove the moisture and oil of braking system. However, the existing air dryer is not suitable for all commercial vehicles. According to the operational status of the new energy vehicles in the initial operating period, the structure design principle of the machine & electric control air dryer is expounded from the aspects of the structure and operating principle, research & development process.
Breathing pulses in singularly perturbed reaction-diffusion systems
NASA Astrophysics Data System (ADS)
Veerman, Frits
2015-07-01
The weakly nonlinear stability of pulses in general singularly perturbed reaction-diffusion systems near a Hopf bifurcation is determined using a centre manifold expansion. A general framework to obtain leading order expressions for the (Hopf) centre manifold expansion for scale separated, localised structures is presented. Using the scale separated structure of the underlying pulse, directly calculable expressions for the Hopf normal form coefficients are obtained in terms of solutions to classical Sturm-Liouville problems. The developed theory is used to establish the existence of breathing pulses in a slowly nonlinear Gierer-Meinhardt system, and is confirmed by direct numerical simulation.
The magnetodynamic filters in monitoring the contaminants from polluted water systems (abstract)
NASA Astrophysics Data System (ADS)
Swarup, R.; Singh, Bharat
1994-05-01
The magnetic interaction seems to influence the ``structural memory'' of water systems which is quenched in ideally pure water. The sedentary lifetime of each water molecule is extremely short (10-10 s) and its molecular structures may be influenced by some physical effect like magnetic field treatment, it's space time gradients, water velocity, pressure drop, etc. in the interpolar space, so as to yield a noticeable temporal magnetopotential development characterizing the properties of homogeneous and heterogeneous water systems. This principle is also extended to prevailing water systems which always contain various impurities, gas, molecules, ions, microscopic particles in random order. Still the existence of structural memory may be verified by reliable experimental data. The magnetopotential curves of different water systems depict the design and develop-software package for constructing the magnetodynamic-filters superior to the existing techniques on pollution studies like remote sensing, muon spin resonance, laser spectroscopy, nuclear techniques, the gamma ray peak efficiency method, trace elemental characterization due to NBS, neutron activation analysis, and graphite furnance atomic absorption spectrometer. The physiochemical characteristics of water calibrated in terms of magnetopotential curves change with the removal of dissolved gasses, impurities, thermal activation, etc. and the algae, bacteria, phosphates, etc. have been removed at a rapid rate. The magnetodynamic study of ganga water proves it to be an extremely pure and highly resourced fluid.
Structure and structure-preserving algorithms for plasma physics
NASA Astrophysics Data System (ADS)
Morrison, P. J.
2016-10-01
Conventional simulation studies of plasma physics are based on numerically solving the underpinning differential (or integro-differential) equations. Usual algorithms in general do not preserve known geometric structure of the physical systems, such as the local energy-momentum conservation law, Casimir invariants, and the symplectic structure (Poincaré invariants). As a consequence, numerical errors may accumulate coherently with time and long-term simulation results may be unreliable. Recently, a series of geometric algorithms that preserve the geometric structures resulting from the Hamiltonian and action principle (HAP) form of theoretical models in plasma physics have been developed by several authors. The superiority of these geometric algorithms has been demonstrated with many test cases. For example, symplectic integrators for guiding-center dynamics have been constructed to preserve the noncanonical symplectic structures and bound the energy-momentum errors for all simulation time-steps; variational and symplectic algorithms have been discovered and successfully applied to the Vlasov-Maxwell system, MHD, and other magnetofluid equations as well. Hamiltonian truncations of the full Vlasov-Maxwell system have opened the field of discrete gyrokinetics and led to the GEMPIC algorithm. The vision that future numerical capabilities in plasma physics should be based on structure-preserving geometric algorithms will be presented. It will be argued that the geometric consequences of HAP form and resulting geometric algorithms suitable for plasma physics studies cannot be adapted from existing mathematical literature but, rather, need to be discovered and worked out by theoretical plasma physicists. The talk will review existing HAP structures of plasma physics for a variety of models, and how they have been adapted for numerical implementation. Supported by DOE DE-FG02-04ER-54742.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Xibing; Dong, Longjun, E-mail: csudlj@163.com; Australian Centre for Geomechanics, The University of Western Australia, Crawley, 6009
This paper presents an efficient closed-form solution (ECS) for acoustic emission(AE) source location in three-dimensional structures using time difference of arrival (TDOA) measurements from N receivers, N ≥ 6. The nonlinear location equations of TDOA are simplified to linear equations. The unique analytical solution of AE sources for unknown velocity system is obtained by solving the linear equations. The proposed ECS method successfully solved the problems of location errors resulting from measured deviations of velocity as well as the existence and multiplicity of solutions induced by calculations of square roots in existed close-form methods.
Schmid-Siegel, B; Stompe, T; Ortwein-Swoboda, G
2004-01-01
Searching through studies of schizophrenic delusions with a view to the new media, we came across the case of a young woman who integrated the Internet in her delusional system. Analysing the story she told, we recognised a psychotic symptom, which we preliminarily called 'perception broadcast'. Perception broadcast shows a more complex structure than the related first rank symptom 'thought broadcast' described by Kurt Schneider. In our view the existence of a structure like perception broadcast depends on the existence of new technologies, such as the World Wide Web and 'virtual reality', creating new cultural patterns which themselves are associated with collective perceptions of derealisation. Copyright 2004 S. Karger AG, Basel
Theoretical and software considerations for nonlinear dynamic analysis
NASA Technical Reports Server (NTRS)
Schmidt, R. J.; Dodds, R. H., Jr.
1983-01-01
In the finite element method for structural analysis, it is generally necessary to discretize the structural model into a very large number of elements to accurately evaluate displacements, strains, and stresses. As the complexity of the model increases, the number of degrees of freedom can easily exceed the capacity of present-day software system. Improvements of structural analysis software including more efficient use of existing hardware and improved structural modeling techniques are discussed. One modeling technique that is used successfully in static linear and nonlinear analysis is multilevel substructuring. This research extends the use of multilevel substructure modeling to include dynamic analysis and defines the requirements for a general purpose software system capable of efficient nonlinear dynamic analysis. The multilevel substructuring technique is presented, the analytical formulations and computational procedures for dynamic analysis and nonlinear mechanics are reviewed, and an approach to the design and implementation of a general purpose structural software system is presented.
NASA Astrophysics Data System (ADS)
Domínguez-Rué, Emma; Mrotzek, Maximilian
2012-10-01
Many interpretations of Shakespearean tragedy have been conducted, mostly following the principles of interpretation in literary study. In our paper, four tragedies by William Shakespeare - Hamlet, King Lear, Othello, and Macbeth - were analysed systemically to find out whether they inhabit a common structure. Using the plot structure as the basis for our analysis, we identified the most important system elements, their connections, and interactive behaviour using causal loop diagrams (CLDs). Our results revealed that all four tragedies basically conform to Senge's archetypal structure 'shifting the burden', adding the action of the heroine or villain and the characters' boundaries of perception. The results suggest that, even though characters and settings vary highly, these tragedies have similar structures and archetypal solutions exist to overcome the problem. Furthermore, we propose that CLDs and systems archetypes are a reasonable hermeneutic tool to analyse not only Shakespearean tragedies but also other literary works.
Implementing Earned Value Management in the CxP EVA Systems Project Office
NASA Technical Reports Server (NTRS)
Sorge, Les L.
2009-01-01
Earned Value Management (EVM), like project management, is as much art as it is science to develop an implementation plan for a project. This presentation will cover issues that were overcome and the implementation strategy to deploy Earned Value Management (EVM) within the Constellation Program (CxP), EVA Systems Project Office (ESPO), as well as discuss additional hurdles that currently prevent the organization from optimizing EVM. Each organization and each project within an organization needs to mold an EVM implementation plan around existing processes and tools, while at the same time revising those existing processes and tools as necessary to make them compatible with EVM. The ESPO EVM implementation covers work breakdown structure, organizational breakdown structure, control account, work/planning package development; integrated master schedule development using an integrated master plan; incorporating reporting requirements for existing funding process such as Planning, Programming, Budgeting, and Execution (PPBE) and JSC Internal Task Agreements (ITA); and interfacing with other software tools such as the Systems Applications and Products (SAP) accounting system and the CxP wInsight EVM analysis tool. However, there are always areas for improvement and EVM is no exception. As EVM continues to mature within the NASA CxP, these areas will continue to be worked to resolution to provide the Program Managers, Project Managers, and Control Account Managers the best EVM data possible to make informed decisions.
Survey on large scale system control methods
NASA Technical Reports Server (NTRS)
Mercadal, Mathieu
1987-01-01
The problem inherent to large scale systems such as power network, communication network and economic or ecological systems were studied. The increase in size and flexibility of future spacecraft has put those dynamical systems into the category of large scale systems, and tools specific to the class of large systems are being sought to design control systems that can guarantee more stability and better performance. Among several survey papers, reference was found to a thorough investigation on decentralized control methods. Especially helpful was the classification made of the different existing approaches to deal with large scale systems. A very similar classification is used, even though the papers surveyed are somehow different from the ones reviewed in other papers. Special attention is brought to the applicability of the existing methods to controlling large mechanical systems like large space structures. Some recent developments are added to this survey.
Imaging Implicit Morphological Processing: Evidence from Hebrew
ERIC Educational Resources Information Center
Bick, Atira S.; Frost, Ram; Goelman, Gadi
2010-01-01
Is morphology a discrete and independent element of lexical structure or does it simply reflect a fine-tuning of the system to the statistical correlation that exists among orthographic and semantic properties of words? Hebrew provides a unique opportunity to examine morphological processing in the brain because of its rich morphological system.…
Winkelman, Warren J; Leonard, Kevin J
2004-01-01
There are constraints embedded in medical record structure that limit use by patients in self-directed disease management. Through systematic review of the literature from a critical perspective, four characteristics that either enhance or mitigate the influence of medical record structure on patient utilization of an electronic patient record (EPR) system have been identified: environmental pressures, physician centeredness, collaborative organizational culture, and patient centeredness. An evaluation framework is proposed for use when considering adaptation of existing EPR systems for online patient access. Exemplars of patient-accessible EPR systems from the literature are evaluated utilizing the framework. From this study, it appears that traditional information system research and development methods may not wholly capture many pertinent social issues that arise when expanding access of EPR systems to patients. Critically rooted methods such as action research can directly inform development strategies so that these systems may positively influence health outcomes.
Automated RTOP Management System
NASA Technical Reports Server (NTRS)
Hayes, P.
1984-01-01
The structure of NASA's Office of Aeronautics and Space Technology electronic information system network from 1983 to 1985 is illustrated. The RTOP automated system takes advantage of existing hardware, software, and expertise, and provides: (1) computerized cover sheet and resources forms; (2) electronic signature and transmission; (3) a data-based information system; (4) graphics; (5) intercenter communications; (6) management information; and (7) text editing. The system is coordinated with Headquarters efforts in codes R,E, and T.
NASA Technical Reports Server (NTRS)
Thomas, Leann; Utley, Dawn
2006-01-01
While there has been extensive research in defining project organizational structures for traditional projects, little research exists to support high technology government project s organizational structure definition. High-Technology Government projects differ from traditional projects in that they are non-profit, span across Government-Industry organizations, typically require significant integration effort, and are strongly susceptible to a volatile external environment. Systems Integration implementation has been identified as a major contributor to both project success and failure. The literature research bridges program management organizational planning, systems integration, organizational theory, and independent project reports, in order to assess Systems Integration (SI) organizational structure selection for improving the high-technology government project s probability of success. This paper will describe the methodology used to 1) Identify and assess SI organizational structures and their success rate, and 2) Identify key factors to be used in the selection of these SI organizational structures during the acquisition strategy process.
Lee, Im-Yeong
2014-01-01
Data outsourcing services have emerged with the increasing use of digital information. They can be used to store data from various devices via networks that are easy to access. Unlike existing removable storage systems, storage outsourcing is available to many users because it has no storage limit and does not require a local storage medium. However, the reliability of storage outsourcing has become an important topic because many users employ it to store large volumes of data. To protect against unethical administrators and attackers, a variety of cryptography systems are used, such as searchable encryption and proxy reencryption. However, existing searchable encryption technology is inconvenient for use in storage outsourcing environments where users upload their data to be shared with others as necessary. In addition, some existing schemes are vulnerable to collusion attacks and have computing cost inefficiencies. In this paper, we analyze existing proxy re-encryption with keyword search. PMID:24693240
Lee, Sun-Ho; Lee, Im-Yeong
2014-01-01
Data outsourcing services have emerged with the increasing use of digital information. They can be used to store data from various devices via networks that are easy to access. Unlike existing removable storage systems, storage outsourcing is available to many users because it has no storage limit and does not require a local storage medium. However, the reliability of storage outsourcing has become an important topic because many users employ it to store large volumes of data. To protect against unethical administrators and attackers, a variety of cryptography systems are used, such as searchable encryption and proxy reencryption. However, existing searchable encryption technology is inconvenient for use in storage outsourcing environments where users upload their data to be shared with others as necessary. In addition, some existing schemes are vulnerable to collusion attacks and have computing cost inefficiencies. In this paper, we analyze existing proxy re-encryption with keyword search.
NASA Astrophysics Data System (ADS)
Hu, Shunren; Chen, Weimin; Liu, Lin; Gao, Xiaoxia
2010-03-01
Bridge structural health monitoring system is a typical multi-sensor measurement system due to the multi-parameters of bridge structure collected from the monitoring sites on the river-spanning bridges. Bridge structure monitored by multi-sensors is an entity, when subjected to external action; there will be different performances to different bridge structure parameters. Therefore, the data acquired by each sensor should exist countless correlation relation. However, complexity of the correlation relation is decided by complexity of bridge structure. Traditionally correlation analysis among monitoring sites is mainly considered from physical locations. unfortunately, this method is so simple that it cannot describe the correlation in detail. The paper analyzes the correlation among the bridge monitoring sites according to the bridge structural data, defines the correlation of bridge monitoring sites and describes its several forms, then integrating the correlative theory of data mining and signal system to establish the correlation model to describe the correlation among the bridge monitoring sites quantificationally. Finally, The Chongqing Mashangxi Yangtze river bridge health measurement system is regards as research object to diagnosis sensors fault, and simulation results verify the effectiveness of the designed method and theoretical discussions.
Using a commodity high-definition television for collaborative structural biology
Yennamalli, Ragothaman; Arangarasan, Raj; Bryden, Aaron; Gleicher, Michael; Phillips, George N.
2014-01-01
Visualization of protein structures using stereoscopic systems is frequently needed by structural biologists working to understand a protein’s structure–function relationships. Often several scientists are working as a team and need simultaneous interaction with each other and the graphics representations. Most existing molecular visualization tools support single-user tasks, which are not suitable for a collaborative group. Expensive caves, domes or geowalls have been developed, but the availability and low cost of high-definition televisions (HDTVs) and game controllers in the commodity entertainment market provide an economically attractive option to achieve a collaborative environment. This paper describes a low-cost environment, using standard consumer game controllers and commercially available stereoscopic HDTV monitors with appropriate signal converters for structural biology collaborations employing existing binary distributions of commonly used software packages like Coot, PyMOL, Chimera, VMD, O, Olex2 and others. PMID:24904249
Enserch Garden Banks 388 field development template tie-back of existing subsea satellite wells
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hellums, J.W.; Granhaug, O.
1995-12-31
The Flowline Jumper System (FJS) will be used by Enserch Exploration, Inc. to tie in three existing wells to the 24 well production template installed in Garden Banks Block 388. The FJS allows these existing satellite wells to be connected to the production template via standard wellbays, eliminating the need for dedicated receiver structures, or tie-in porches. Wellbays used for satellite well tie-ins are available for use as template wells following the removal of the jumper. This paper describes the considerations that led to the selection and influenced the design of the FJS. The advantages of vertical jumper systems aremore » fully discussed with respect to the GB-388 Project. A description of the major components and how they interface with the template is included to provide a better understanding of the FJS. Also included is an outline of the System Integration Testing (SIT) of the FJS.« less
Necessary and sufficient liveness condition of GS3PR Petri nets
NASA Astrophysics Data System (ADS)
Liu, GaiYun; Barkaoui, Kamel
2015-05-01
Structural analysis is one of the most important and efficient methods to investigate the behaviour of Petri nets. Liveness is a significant behavioural property of Petri nets. Siphons, as structural objects of a Petri net, are closely related to its liveness. Many deadlock control policies for flexible manufacturing systems (FMS) modelled by Petri nets are implemented via siphon control. Most of the existing methods design liveness-enforcing supervisors by adding control places for siphons based on their controllability conditions. To compute a liveness-enforcing supervisor with as much as permissive behaviour, it is both theoretically and practically significant to find an exact controllability condition for siphons. However, the existing conditions, max, max‧, and max″-controllability of siphons are all overly restrictive and generally sufficient only. This paper develops a new condition called max*-controllability of the siphons in generalised systems of simple sequential processes with resources (GS3PR), which are a net subclass that can model many real-world automated manufacturing systems. We show that a GS3PR is live if all its strict minimal siphons (SMS) are max*-controlled. Compared with the existing conditions, i.e., max-, max‧-, and max″-controllability of siphons, max*-controllability of the SMS is not only sufficient but also necessary. An example is used to illustrate the proposed method.
SDSL-ESR-based protein structure characterization.
Strancar, Janez; Kavalenka, Aleh; Urbancic, Iztok; Ljubetic, Ajasja; Hemminga, Marcus A
2010-03-01
As proteins are key molecules in living cells, knowledge about their structure can provide important insights and applications in science, biotechnology, and medicine. However, many protein structures are still a big challenge for existing high-resolution structure-determination methods, as can be seen in the number of protein structures published in the Protein Data Bank. This is especially the case for less-ordered, more hydrophobic and more flexible protein systems. The lack of efficient methods for structure determination calls for urgent development of a new class of biophysical techniques. This work attempts to address this problem with a novel combination of site-directed spin labelling electron spin resonance spectroscopy (SDSL-ESR) and protein structure modelling, which is coupled by restriction of the conformational spaces of the amino acid side chains. Comparison of the application to four different protein systems enables us to generalize the new method and to establish a general procedure for determination of protein structure.
High voltage system: Plasma interaction summary
NASA Technical Reports Server (NTRS)
Stevens, N. John
1986-01-01
The possible interactions that could exist between a high voltage system and the space plasma environment are reviewed. A solar array is used as an example of such a system. The emphasis in this review is on the discrepancies that exist in this technology in both flight and ground experiment data. It has been found that, in ground testing, there are facility effects, cell size effects and area scaling uncertainties. For space applications there are area scaling and discharge concerns for an array as well as the influence of the large space structures on the collection process. There are still considerable uncertainties in the high voltage-space plasma interaction technology even after several years of effort.
Probing quantum frustrated systems via factorization of the ground state.
Giampaolo, Salvatore M; Adesso, Gerardo; Illuminati, Fabrizio
2010-05-21
The existence of definite orders in frustrated quantum systems is related rigorously to the occurrence of fully factorized ground states below a threshold value of the frustration. Ground-state separability thus provides a natural measure of frustration: strongly frustrated systems are those that cannot accommodate for classical-like solutions. The exact form of the factorized ground states and the critical frustration are determined for various classes of nonexactly solvable spin models with different spatial ranges of the interactions. For weak frustration, the existence of disentangling transitions determines the range of applicability of mean-field descriptions in biological and physical problems such as stochastic gene expression and the stability of long-period modulated structures.
Electromagnetic properties of ice coated surfaces
NASA Technical Reports Server (NTRS)
Dominek, A.; Walton, E.; Wang, N.; Beard, L.
1989-01-01
The electromagnetic scattering from ice coated structures is examined. The influence of ice is shown from a measurement standpoint and related to a simple analytical model. A hardware system for the realistic measurement of ice coated structures is also being developed to use in an existing NASA Lewis icing tunnel. Presently, initial measurements have been performed with a simulated tunnel to aid in the development.
Does stand density affect mating system and population genetic structure in coast live oak?
Kathryn Beals; Richard S. Dodd
2006-01-01
Coast live oak (Quercus agrifolia) is a major species at risk in the current Phytophthora ramorum epidemic in Californiaâs oak woodlands. To search effectively for resistant genotypes, it is imperative to have an understanding of the existing host population genetic structure in these forests, and how its reproductive capacity may...
Attitude Dynamics, Stability, and Control of a Heliogyro Solar Sail
NASA Astrophysics Data System (ADS)
Pimienta-Penalver, Adonis Reinier
A heliogyro solar sail concept, dubbed `HELIOS', is proposed as an alternative to deep space missions without the need for on-board propellant. Although this type of solar sail has existed in concept for several decades, and some previous studies have investigated certain aspects of its operation, a significant amount of research is still needed to analyze the dynamic and control characteristics of the structure under the projected range of orbital conditions. This work presents an improvement upon the existing discrete-mass models of the heliogyro blade, and the extension of its application from a single membrane blade to a fully-coupled approximation of the dynamics of the HELIOS system with multiple spinning membrane blades around a central hub. The incorporation of structural stiffness and external forcing effects into the model is demonstrated to add a further degree of fidelity in simulating the stability properties of the system. Additionally, the approximated dynamics of multiple-blade heliogyro structures are examined under the effect of solar radiation pressure. Lastly, this study evaluates a control algorithm at each blade root to impose structural integrity and attitude control by coordinating well-known helicopter blade pitching profiles.
Cyber Physical Systems for User Reliability Measurements in a Sharing Economy Environment
Seo, Aria; Kim, Yeichang
2017-01-01
As the sharing economic market grows, the number of users is also increasing but many problems arise in terms of reliability between providers and users in the processing of services. The existing methods provide shared economic systems that judge the reliability of the provider from the viewpoint of the user. In this paper, we have developed a system for establishing mutual trust between providers and users in a shared economic environment to solve existing problems. In order to implement a system that can measure and control users’ situation in a shared economic environment, we analyzed the necessary factors in a cyber physical system (CPS). In addition, a user measurement system based on a CPS structure in a sharing economic environment is implemented through analysis of the factors to consider when constructing a CPS. PMID:28805709
Cyber Physical Systems for User Reliability Measurements in a Sharing Economy Environment.
Seo, Aria; Jeong, Junho; Kim, Yeichang
2017-08-13
As the sharing economic market grows, the number of users is also increasing but many problems arise in terms of reliability between providers and users in the processing of services. The existing methods provide shared economic systems that judge the reliability of the provider from the viewpoint of the user. In this paper, we have developed a system for establishing mutual trust between providers and users in a shared economic environment to solve existing problems. In order to implement a system that can measure and control users' situation in a shared economic environment, we analyzed the necessary factors in a cyber physical system (CPS). In addition, a user measurement system based on a CPS structure in a sharing economic environment is implemented through analysis of the factors to consider when constructing a CPS.
Classification of polytype structures of zinc sulfide
DOE Office of Scientific and Technical Information (OSTI.GOV)
Laptev, V.I.
1994-12-31
It is suggested that the existing classification of polytype structures of zinc sulfide be supplemented with an additional criterion: the characteristic of regular point systems (Wyckoff positions) including their type, number, and multiplicity. The consideration of the Wyckoff positions allowed the establishment of construction principles of known polytype series of different symmetries and the systematization (for the first time) of the polytypes with the same number of differently packed layers. the classification suggested for polytype structures of zinc sulfide is compact and provides a basis for creating search systems. The classification table obtained can also be used for numerous siliconmore » carbide polytypes. 8 refs., 4 tabs.« less
In-Space Structural Assembly: Applications and Technology
NASA Technical Reports Server (NTRS)
Belvin, W. Keith; Doggett, Bill R.; Watson, Judith J.; Dorsey, John T.; Warren, Jay; Jones, Thomas C.; Komendera, Erik E.; Mann, Troy O.; Bowman, Lynn
2016-01-01
As NASA exploration moves beyond earth's orbit, the need exists for long duration space systems that are resilient to events that compromise safety and performance. Fortunately, technology advances in autonomy, robotic manipulators, and modular plug-and-play architectures over the past two decades have made in-space vehicle assembly and servicing possible at acceptable cost and risk. This study evaluates future space systems needed to support scientific observatories and human/robotic Mars exploration to assess key structural design considerations. The impact of in-space assembly is discussed to identify gaps in structural technology and opportunities for new vehicle designs to support NASA's future long duration missions.
NASA Technical Reports Server (NTRS)
Demeo, Martha E.
1990-01-01
The feasibility of an experiment which will provide an on-orbit validation of Controls-Structures Interaction (CSI) technology, was investigated. The experiment will demonstrate the on-orbit characterization and flexible-body control of large flexible structure dynamics using the shuttle Remote Manipulator System (RMS) with an attached payload as a test article. By utilizing existing hardware as well as establishing integration, operation and safety algorithms, techniques and procedures, the experiment will minimize the costs and risks of implementing a flight experiment. The experiment will also offer spin-off enhancement to both the Shuttle RMS (SRMS) and the Space Station RMS (SSRMS).
Spiegel, David S.; Fortney, Jonathan J.; Sotin, Christophe
2014-01-01
The hundreds of exoplanets that have been discovered in the past two decades offer a new perspective on planetary structure. Instead of being the archetypal examples of planets, those of our solar system are merely possible outcomes of planetary system formation and evolution, and conceivably not even especially common outcomes (although this remains an open question). Here, we review the diverse range of interior structures that are both known and speculated to exist in exoplanetary systems—from mostly degenerate objects that are more than 10× as massive as Jupiter, to intermediate-mass Neptune-like objects with large cores and moderate hydrogen/helium envelopes, to rocky objects with roughly the mass of Earth. PMID:24379369
Exploring the significance of structural hierarchy in material systems-A review
NASA Astrophysics Data System (ADS)
Pan, Ning
2014-06-01
Structural hierarchy and heterogeneity are inherent features in biological materials, but their significance in affecting the system behaviors is yet to be fully understood. In Sec. I, this article first identifies the major characteristics that manifest, or are resulted from, such hierarchy and heterogeneity in materials. Then in Sec. II, it presents several typical natural material systems including wood, bone, and others from animals to illustrate the proposed views. The paper also discusses a man-made smart material, textiles, to demonstrate that textiles are hierarchal, multifunctional, highly complex, and arguably the engineered material closest on a par with biological materials in complexity, and, more importantly, we can still learn quite a few new things from them in development of novel materials. In Sec. III, the paper summarizes several general approaches in developing a hierarchal material system at various scales, including structure thinning and splitting, laminating and layering, spatial and angular orientation, heterogenization and hybridization, and analyzes the advantages associated with them. It also stresses the adverse consequences once the existing structural hierarchy breaks down due to various mutations in biological systems. It discusses, in particular, the influences of moisture and air on material properties, given the near ubiquitousness of both air and water in materials. It next deals with in Sec. IV, some theoretical issues in material research including packing and ordering, the bi-modular mechanics, the behavior non-affinities due to disparity in hierarchal levels, the importance of system dimensionality in a hierarchal material system, and more philosophically, the issues of Nature's wisdom versus Intelligent Design. Section V then offers some concluding remarks, including a recap of the major issues covered in this article, and some general conclusions derived from the analyses and discussions. The main purpose of this paper is to make an effort to explore, identify, derive, or theorize some generic principles based on the existing results, not to offer another comprehensive review of current research activities in the fields for that there already exist some excellent ones. This paper examines the related topics with several approaches to not only reveal the underlying geometrical and physical mechanisms but also to emphasize the ways in which such mechanisms may be applied to developing engineered material systems with novel properties.
Liu, Qingyou; Tang, Yang; Huang, Chongjun; Xie, Chong
2015-01-01
There are some disadvantages for existing heave compensation systems of drill string used for the Floating Drilling Platform (FDP), including high energy consumption, large and complex structure, and expensive manufacturing and maintenance costs. In view of the above, we present a streamlined mechanical semi-active heave compensation system (MSAHC) in this study. This system consists of active compensation part with the pinion and rack and passive compensation part. In order to evaluate system performance of the MSAHC, we establish its simulation model with AMEsim software. In the process of simulation, displacement of rotary hook and energy consumption is regarded as performance parameters of the system. And the change rule of two performance parameters are analyzed by changing these design parameters including gear radius of the pinion and rack, scale coefficient of PID, rotary hook load, heave height and heave period of the FDP, and accumulator volume. Then, based on the simulation results of the MSAHC system performance, we have selected out a best set of design parameters from them. Moreover, the feasibility of the design scheme of the MSAHC is effectively verified by comparison with the existing three heave compensation system. The result shows that the energy consumption of the MSAHC is lower than the active heave compensation system (AHC) and the semi-active heave compensation system (SAHC) when achieving a same compensation effect as well as the accumulator volume of MSAHC is half of the passive heave compensation system (PHC). Therefore, the new designed MSAHC not only ensure compensation effect but also lower energy consumption, and its structure is simplified by adopting the simple mechanical structure to decrease manufacturing cost, maintenance cost and floor space. PMID:26186620
Electrically conductive concrete : a laboratory study.
DOT National Transportation Integrated Search
1987-01-01
In the cathodic protection of existing reinforced concrete bridge decks, there is a need for a simple secondary-anode system to facilitate the distribution of direct current over the structure being protected. It is believed that a durable, electrica...
Models for predicting adverse outcomes can help reduce and focus animal testing with new and existing chemicals. This short "thought starter" describes how quantitative-structure activity relationship and systems biology models can be used to help define toxicity pathways and li...
Vibration isolation by exploring bio-inspired structural nonlinearity.
Wu, Zhijing; Jing, Xingjian; Bian, Jing; Li, Fengming; Allen, Robert
2015-10-08
Inspired by the limb structures of animals/insects in motion vibration control, a bio-inspired limb-like structure (LLS) is systematically studied for understanding and exploring its advantageous nonlinear function in passive vibration isolation. The bio-inspired system consists of asymmetric articulations (of different rod lengths) with inside vertical and horizontal springs (as animal muscle) of different linear stiffness. Mathematical modeling and analysis of the proposed LLS reveal that, (a) the system has very beneficial nonlinear stiffness which can provide flexible quasi-zero, zero and/or negative stiffness, and these nonlinear stiffness properties are adjustable or designable with structure parameters; (b) the asymmetric rod-length ratio and spring-stiffness ratio present very beneficial factors for tuning system equivalent stiffness; (c) the system loading capacity is also adjustable with the structure parameters which presents another flexible benefit in application. Experiments and comparisons with existing quasi-zero-stiffness isolators validate the advantageous features above, and some discussions are also given about how to select structural parameters for practical applications. The results would provide an innovative bio-inspired solution to passive vibration control in various engineering practice.
X-ray Crystal Structures of the Type IVb Secretion System DotB ATPases.
Prevost, Marie S; Waksman, Gabriel
2018-05-17
Human infections by the intracellular bacterial pathogen Legionella pneumophila result in a severe form of pneumonia, the Legionnaire's disease. L. pneumophila utilises a type IVb secretion (T4bS) system termed "dot/icm" to secrete protein effectors to the host cytoplasm. The dot/icm system is powered at least in part by a functionally critical AAA+ ATPase, a protein called DotB, thought to belong to the VirB11 family of proteins. Here we present the crystal structure of DotB at 3.19 Å resolution, in its hexameric form. We observe that DotB is in fact a structural intermediate between VirB11 and PilT family proteins, with a PAS-like N-terminal domain coupled to a RecA-like C-terminal domain. It also shares critical structural elements only found in PilT. The structure also reveals two conformers, termed α and β, with an αβαβαβ configuration. The existence of α and β conformers in this class of proteins was confirmed by solving the structure of DotB from another bacterial pathogen, Yersinia, where, intriguingly, we observed an ααβααβ configuration. The two conformers co-exist regardless of the nucleotide-bound states of the proteins. Our investigation therefore reveals that these ATPases can adopt a wider range of conformational states than was known before, shedding new light on the extraordinary spectrum of conformations these ATPases can access to carry out their function. Overall, the structure of DotB provides a template for further rational drug-design to develop more specific antibiotics to tackle Legionnaire's disease. This article is protected by copyright. All rights reserved. © 2018 The Protein Society.
NASA Technical Reports Server (NTRS)
Shen, Ji Y.; Sharpe, Lonnie, Jr.
1998-01-01
The research activity for this project is mainly to investigate the necessity and feasibility to develop a structural health monitoring system for rocket engines, and to carry out a research plan for further development of the system. More than one hundred technical papers have been searched and reviewed during the period. We concluded after this investigation that adding a new module in NASA's existing automated diagnostic system to monitor the healthy condition of rocket engine structures is a crucial task, and it's possible to develop such a system based upon the vibrational-based nondestructive damage assessment techniques. A number of such techniques have been introduced. Their advantages and disadvantages are also discussed. A global research plan has been figured out. As the first step of the overall research plan, a proposal for the next fiscal year has been submitted.
Thermal/structural design verification strategies for large space structures
NASA Technical Reports Server (NTRS)
Benton, David
1988-01-01
Requirements for space structures of increasing size, complexity, and precision have engendered a search for thermal design verification methods that do not impose unreasonable costs, that fit within the capabilities of existing facilities, and that still adequately reduce technical risk. This requires a combination of analytical and testing methods. This requires two approaches. The first is to limit thermal testing to sub-elements of the total system only in a compact configuration (i.e., not fully deployed). The second approach is to use a simplified environment to correlate analytical models with test results. These models can then be used to predict flight performance. In practice, a combination of these approaches is needed to verify the thermal/structural design of future very large space systems.
Aubry-Mather Theory for Conformally Symplectic Systems
NASA Astrophysics Data System (ADS)
Marò, Stefano; Sorrentino, Alfonso
2017-09-01
In this article we develop an analogue of Aubry-Mather theory for a class of dissipative systems, namely conformally symplectic systems, and prove the existence of interesting invariant sets, which, in analogy to the conservative case, will be called the Aubry and the Mather sets. Besides describing their structure and their dynamical significance, we shall analyze their attracting/repelling properties, as well as their noteworthy role in driving the asymptotic dynamics of the system.
Frequency domain modeling and dynamic characteristics evaluation of existing wind turbine systems
NASA Astrophysics Data System (ADS)
Chiang, Chih-Hung; Yu, Chih-Peng
2016-04-01
It is quite well accepted that frequency domain procedures are suitable for the design and dynamic analysis of wind turbine structures, especially for floating offshore wind turbines, since random wind loads and wave induced motions are most likely simulated in the frequency domain. This paper presents specific applications of an effective frequency domain scheme to the linear analysis of wind turbine structures in which a 1-D spectral element was developed based on the axially-loaded member. The solution schemes are summarized for the spectral analyses of the tower, the blades, and the combined system with selected frequency-dependent coupling effect from foundation-structure interactions. Numerical examples demonstrate that the modal frequencies obtained using spectral-element models are in good agreement with those found in the literature. A 5-element mono-pile model results in less than 0.3% deviation from an existing 160-element model. It is preliminarily concluded that the proposed scheme is relatively efficient in performing quick verification for test data obtained from the on-site vibration measurement using the microwave interferometer.
A stage structure pest management model with impulsive state feedback control
NASA Astrophysics Data System (ADS)
Pang, Guoping; Chen, Lansun; Xu, Weijian; Fu, Gang
2015-06-01
A stage structure pest management model with impulsive state feedback control is investigated. We get the sufficient condition for the existence of the order-1 periodic solution by differential equation geometry theory and successor function. Further, we obtain a new judgement method for the stability of the order-1 periodic solution of the semi-continuous systems by referencing the stability analysis for limit cycles of continuous systems, which is different from the previous method of analog of Poincarè criterion. Finally, we analyze numerically the theoretical results obtained.
[ISO 9001:2015 Certification in Quality Management].
Enders, Christian; Lang, Gabriele E; Lang, Gerhard K; Werner, Jens Ulrich
2017-07-01
Quality management improves the structures, processes and results of organizations of all kinds. Many practices and clinics have their existing quality management system certified according to ISO 9001, (e.g., to check their own quality management system or to obtain a testimonial against third parties). The latest version ISO 9001:2015 contains some changes, both structurally and in terms of content. These changes can be met with reasonable efforts. An ISO 9001:2015 certification represents a value for your organization, but these advantages are often not directly measurable. Georg Thieme Verlag KG Stuttgart · New York.
The School of the Future. Stelco Trend. Number 34 in a Series.
ERIC Educational Resources Information Center
Walker, Howard V.; Arthur, E. R.
Floor plans and illustrations present a simplified building system for an elementary school that can be utilized by any school board. All components for the system can be drawn from existing products and readily integrated with the structure. The component assembly and connections are illustrated in detail. Factory production is utilized to reduce…
Salmon, Paul M; Read, Gemma J M; Stevens, Nicholas J
2016-11-01
Despite significant progress, road trauma continues to represent a global safety issue. In Queensland (Qld), Australia, there is currently a focus on preventing the 'fatal five' behaviours underpinning road trauma (drug and drink driving, distraction, seat belt wearing, speeding, and fatigue), along with an emphasis on a shared responsibility for road safety that spans road users, vehicle manufacturers, designers, policy makers etc. The aim of this article is to clarify who shares the responsibility for road safety in Qld and to determine what control measures are enacted to prevent the fatal five behaviours. This is achieved through the presentation of a control structure model that depicts the actors and organisations within the Qld road transport system along with the control and feedback relationships that exist between them. Validated through a Delphi study, the model shows a diverse set of actors and organisations who share the responsibility for road safety that goes beyond those discussed in road safety policies and strategies. The analysis also shows that, compared to other safety critical domains, there are less formal control structures in road transport and that opportunities exist to add new controls and strengthen existing ones. Relationships that influence rather than control are also prominent. Finally, when compared to other safety critical domains, the strength of road safety controls is brought into question. Copyright © 2016 Elsevier Ltd. All rights reserved.
Structure of public transit costs in the presence of multiple serial correlation
DOT National Transportation Integrated Search
1999-12-01
Most studies indicate that public transit systems operate under increasing returns to capital stock utilization and are significantly overcapitalized. Existing flexible form time series analyses, however, fail to correct for serial correlation. In th...
Enhanced two phase flow in heat transfer systems
Tegrotenhuis, Ward E; Humble, Paul H; Lavender, Curt A; Caldwell, Dustin D
2013-12-03
A family of structures and designs for use in devices such as heat exchangers so as to allow for enhanced performance in heat exchangers smaller and lighter weight than other existing devices. These structures provide flow paths for liquid and vapor and are generally open. In some embodiments of the invention, these structures can also provide secondary heat transfer as well. In an evaporate heat exchanger, the inclusion of these structures and devices enhance the heat transfer coefficient of the evaporation phase change process with comparable or lower pressure drop.
Low-thrust chemical orbit transfer propulsion
NASA Technical Reports Server (NTRS)
Pelouch, J. J., Jr.
1979-01-01
The need for large structures in high orbit is reported in terms of the many mission opportunities which require such structures. Mission and transportation options for large structures are presented, and it is shown that low-thrust propulsion is an enabling requirement for some missions and greatly enhancing to many others. Electric and low-thrust chemical propulsion are compared, and the need for an requirements of low-thrust chemical propulsion are discussed in terms of the interactions that are perceived to exist between the propulsion system and the large structure.
High frequency flow-structural interaction in dense subsonic fluids
NASA Technical Reports Server (NTRS)
Liu, Baw-Lin; Ofarrell, J. M.
1995-01-01
Prediction of the detailed dynamic behavior in rocket propellant feed systems and engines and other such high-energy fluid systems requires precise analysis to assure structural performance. Designs sometimes require placement of bluff bodies in a flow passage. Additionally, there are flexibilities in ducts, liners, and piping systems. A design handbook and interactive data base have been developed for assessing flow/structural interactions to be used as a tool in design and development, to evaluate applicable geometries before problems develop, or to eliminate or minimize problems with existing hardware. This is a compilation of analytical/empirical data and techniques to evaluate detailed dynamic characteristics of both the fluid and structures. These techniques have direct applicability to rocket engine internal flow passages, hot gas drive systems, and vehicle propellant feed systems. Organization of the handbook is by basic geometries for estimating Strouhal numbers, added mass effects, mode shapes for various end constraints, critical onset flow conditions, and possible structural response amplitudes. Emphasis is on dense fluids and high structural loading potential for fatigue at low subsonic flow speeds where high-frequency excitations are possible. Avoidance and corrective measure illustrations are presented together with analytical curve fits for predictions compiled from a comprehensive data base.
Mathematical Methods of System Analysis in Construction Materials
NASA Astrophysics Data System (ADS)
Garkina, Irina; Danilov, Alexander
2017-10-01
System attributes of construction materials are defined: complexity of an object, integrity of set of elements, existence of essential, stable relations between elements defining integrative properties of system, existence of structure, etc. On the basis of cognitive modelling (intensive and extensive properties; the operating parameters) materials (as difficult systems) and creation of the cognitive map the hierarchical modular structure of criteria of quality is under construction. It actually is a basis for preparation of the specification on development of material (the required organization and properties). Proceeding from a modern paradigm (model of statement of problems and their decisions) of development of materials, levels and modules are specified in structure of material. It when using the principles of the system analysis allows to considered technological process as the difficult system consisting of elements of the distinguished specification level: from atomic before separate process. Each element of system depending on an effective objective is considered as separate system with more detailed levels of decomposition. Among them, semantic and qualitative analyses of an object (are considered a research objective, decomposition levels, separate elements and communications between them come to light). Further formalization of the available knowledge in the form of mathematical models (structural identification) is carried out; communications between input and output parameters (parametrical identification) are defined. Hierarchical structures of criteria of quality are under construction for each allocated level. On her the relevant hierarchical structures of system (material) are under construction. Regularities of structurization and formation of properties, generally are considered at the levels from micro to a macrostructure. The mathematical model of material is represented as set of the models corresponding to private criteria by which separate modules and their levels (the mathematical description, a decision algorithm) are defined. Adequacy is established (compliance of results of modelling to experimental data; is defined by the level of knowledge of process and validity of the accepted assumptions). The global criterion of quality of material is considered as a set of private criteria (properties). Synthesis of material is carried out on the basis of one-criteria optimization on each of the chosen private criteria. Results of one-criteria optimization are used at multicriteria optimization. The methods of developing materials as single-purpose, multi-purpose, including contradictory, systems are indicated. The scheme of synthesis of composite materials as difficult systems is developed. The specified system approach effectively was used in case of synthesis of composite materials with special properties.
NASA Technical Reports Server (NTRS)
Plachta, David W.; Tucker, Stephen; Hoffman, David J.
1993-01-01
This paper analyzes, defines, and sizes cryogenic storage thermal control systems that meet the requirements of future NASA Mars human exploration missions. The design issues of this system include the projection of the existing Multilayer Insulation data base for cryogenic storage to much thicker (10 cm or more) insulation systems, the unknown heat leak from mechanical interfaces, and the thermal and structural performance effects of the large tank sizes required for a Mars mission. Acknowledging these unknown effects, heat loss projections are made based on extrapolation of the existing data base. The results indicate that hydrogen, methane, and oxygen are feasible propellants, and that the best suited thermal control sytems are 'thick' MLI, thermodynamic vent sytems, cryocoolers, and vacuum jackets.
Transversal homoclinic orbits in a transiently chaotic neural network.
Chen, Shyan-Shiou; Shih, Chih-Wen
2002-09-01
We study the existence of snap-back repellers, hence the existence of transversal homoclinic orbits in a discrete-time neural network. Chaotic behaviors for the network system in the sense of Li and Yorke or Marotto can then be concluded. The result is established by analyzing the structures of the system and allocating suitable parameters in constructing the fixed points and their pre-images for the system. The investigation provides a theoretical confirmation on the scenario of transient chaos for the system. All the parameter conditions for the theory can be examined numerically. The numerical ranges for the parameters which yield chaotic dynamics and convergent dynamics provide significant information in the annealing process in solving combinatorial optimization problems using this transiently chaotic neural network. (c) 2002 American Institute of Physics.
DFL, Canada's Space AIT Facilities - Current and Planned Capabilities
NASA Astrophysics Data System (ADS)
Singhal, R.; Mishra, S.; Choueiry, E.; Dumoulin, J.; Ahmed, S.
2004-08-01
The David Florida Laboratory (DFL) of the Canadian Space Agency is the Canadian national ISO 9001:2000 registered facility for the assembly, integration, and (environmental) testing of space hardware. This paper briefly describes the three main qualification facilities: Structural Qualification Facilities (SQF); Radio Frequency Qualification Facilities (RFQF); and Thermal Qualification Facilities (TQF). The paper also describes the planned/new upgrades/improvements to the DFL's existing capabilities. These include: cylindrical near-field antenna measurement system, current capabilities in multi-frequency multi-band passive intermodulation (PIM) measurement; combined thermal/vibration test facility, improvement in efficiency and performance of the photogrammetry capability, acquisition of an additional mass properties measurement system for small and micro-satellites; combined control and data acquisition system for all existing thermal vacuum facilities, plus a new automatic thermal control system and hypobaric chamber.
The New Kid on the Block: A Specialized Secretion System during Bacterial Sporulation.
Morlot, Cécile; Rodrigues, Christopher D A
2018-02-02
The transport of proteins across the bacterial cell envelope is mediated by protein complexes called specialized secretion systems. These nanomachines exist in both Gram-positive and Gram-negative bacteria and have been categorized into different types based on their structural components and function. Interestingly, multiple studies suggest the existence of a protein complex in endospore-forming bacteria that appears to be a new type of specialized secretion system. This protein complex is called the SpoIIIA-SpoIIQ complex and is an exception to the categorical norm since it appears to be a hybrid composed of different parts from well-defined specialized secretion systems. Here we summarize and discuss the current understanding of this complex and its potential role as a specialized secretion system. Copyright © 2018 Elsevier Ltd. All rights reserved.
Public Health's Approach to Systemic Racism: a Systematic Literature Review.
Castle, Billie; Wendel, Monica; Kerr, Jelani; Brooms, Derrick; Rollins, Aaron
2018-05-04
Recently, public health has acknowledged racism as a social determinant of health. Much evidence exists on the impact of individual-level racism and discrimination, with little to no examination of racism from the standpoint of systems and structures. The purpose of this systematic literature review is to analyze the extent to which public health currently addresses systemic racism in the published literature. Utilizing the PRISMA guidelines, this review examines three widely used databases to examine published literature covering the topic as well as implications for future research and practice. A total of 85 articles were included in the review analysis after meeting study criteria. Across numerous articles, the terms racism and systemic racism are largely absent. A critical need exists for an examination of the historical impact of systemic racism on the social determinants of health and health of marginalized populations.
Cunningham, Kevin J.
2014-01-01
The U.S. Geological Survey and Broward County water managers commenced a 3.5-year cooperative study in July 2012 to refine the geologic and hydrogeologic framework of the Floridan aquifer system (FAS) in Broward County. A lack of advanced stratigraphic knowledge of the physical system and structural geologic anomalies (faults and fractures originating from tectonics and karst-collapse structures) within the FAS pose a risk to the sustainable management of the resource. The principal objective of the study is to better define the regional stratigraphic and structural setting of the FAS in Broward County. The objective will be achieved through the acquisition, processing, and interpretation of new seismic-reflection data along several canals in Broward County. The interpretation includes integration of the new seismic-reflection data with existing seismic-reflection profiles along Hillsboro Canal in Broward County and within northeast Miami-Dade County, as well as with data from nearby FAS wellbores. The scope of the study includes mapping the geologic, hydrogeologic, and seismic-reflection framework of the FAS, and identifying stratigraphic and structural characteristics that could either facilitate or preclude the sustainable use of the FAS as an alternate water supply or a treated effluent repository. In addition, the investigation offers an opportunity to: (1) improve existing groundwater flow models, (2) enhance the understanding of the sensitivity of the groundwater system to well-field development and upconing of saline fluids, and (3) support site selection for future FAS projects, such as Class I wells that would inject treated effluent into the deep Boulder Zone.
Di, Filippo M.; Lombardi, S.; Nappi, G.; Reimer, G.M.; Renzulli, A.; Toro, B.
1999-01-01
Since the early 1980s, geological and structural mapping, gravity, and helium soil-gas studies have been performed in the eastern sector of the Vulsini Volcanic District (Roman Magmatic Province) in an attempt to locate potential geothermal reservoirs. This area is characterised by an anomalous geothermal gradient of > 100??C/km, and by widespread hydrothermal mineralization, thermal springs, high gas fluxes, and fossil and current travertine deposits. The results of these surveys indicate the existence of a number of fault systems, with N-S and E-W structures that appear to be superimposed on older NW-SE and NE-SW features. Comparison of the results of the various studies also reveals differences in permeability and potential reservoir structures at depth.Since the early 1980s, geological and structural mapping, gravity, and helium soil-gas studies have been performed in the eastern sector of the Vulsini Volcanic District (Roman Magmatic Province) in an attempt to locate potential geothermal reservoirs. This area is characterised by an anomalous geothermal gradient of > 100??C/km, and by widespread hydrothermal mineralization, thermal springs, high gas fluxes, and fossil and current travertine deposits. The results of these surveys indicate the existence of a number of fault systems, with N-S and E-W structures that appear to be superimposed on older NW-SE and NE-SW features. Comparison of the results of the various studies also reveals differences in permeability and potential reservoir structures at depth.
ERIC Educational Resources Information Center
Floryan, Mark
2013-01-01
This dissertation presents a novel effort to develop ITS technologies that adapt by observing student behavior. In particular, we define an evolving expert knowledge base (EEKB) that structures a domain's information as a set of nodes and the relationships that exist between those nodes. The structure of this model is not the particularly novel…
Technology Transferred to the Kirby Company
NASA Technical Reports Server (NTRS)
1996-01-01
NASA Lewis Research Center's Propulsion Systems Branch, evaluated the structural and vibration characteristics of the Kirby Model G-4 fan. Modes of vibration and resonance potential were evaluated in the Holography Test Lab at Lewis. As a result of the Lewis tests and rotor structural evaluation, Kirby engineers gained new insights into their existing design, enabling them to develop a more robust fan for use in their vacuum cleaners.
Defect Structure of Beta NiAl Using the BFS Method for Alloys
NASA Technical Reports Server (NTRS)
Bozzolo, Guillermo; Amador, Carlos; Ferrante, John; Noebe, Ronald D.
1996-01-01
The semiempirical BFS method for alloys is generalized by replacing experimental input with first-principles results thus allowing for the study of complex systems. In order to examine trends and behavior of a system in the vicinity of a given point of the phase diagram a search procedure based on a sampling of selected configurations is employed. This new approach is applied to the study of the beta phase of the Ni-Al system, which exists over a range of composition from 45-60 at.% Ni. This methodology results in a straightforward and economical way of reproducing and understanding the basic features of this system. At the stoichiometric composition, NiAl should exist in a perfectly ordered B2 structure. Ni-rich alloys are characterized by antisite point defects (with Ni atoms in the Al sites) with a decrease in lattice parameters. On the Al-rich side of stoichiometry there is a steep decrease in lattice parameter and density with increasing Al content. The presence of vacancies in Ni sites would explain such behavior. Recent X-ray diffraction experiments suggest a richer structure: the evidence, while strongly favoring the presence of vacancies in Ni sites, also suggests the possibility of some vacancies in Al sites in a 3:1 ratio. Moreover, local ordering of vacant sites may be preferred over a random distribution of individual point defects.
Mackintosh, Maureen; Channon, Amos; Karan, Anup; Selvaraj, Sakthivel; Cavagnero, Eleonora; Zhao, Hongwen
2016-08-06
Private health care in low-income and middle-income countries is very extensive and very heterogeneous, ranging from itinerant medicine sellers, through millions of independent practitioners-both unlicensed and licensed-to corporate hospital chains and large private insurers. Policies for universal health coverage (UHC) must address this complex private sector. However, no agreed measures exist to assess the scale and scope of the private health sector in these countries, and policy makers tasked with managing and regulating mixed health systems struggle to identify the key features of their private sectors. In this report, we propose a set of metrics, drawn from existing data that can form a starting point for policy makers to identify the structure and dynamics of private provision in their particular mixed health systems; that is, to identify the consequences of specific structures, the drivers of change, and levers available to improve efficiency and outcomes. The central message is that private sectors cannot be understood except within their context of mixed health systems since private and public sectors interact. We develop an illustrative and partial country typology, using the metrics and other country information, to illustrate how the scale and operation of the public sector can shape the private sector's structure and behaviour, and vice versa. Copyright © 2016 Elsevier Ltd. All rights reserved.
Future Launch Vehicle Structures - Expendable and Reusable Elements
NASA Astrophysics Data System (ADS)
Obersteiner, M. H.; Borriello, G.
2002-01-01
Further evolution of existing expendable launch vehicles will be an obvious element influencing the future of space transportation. Besides this reusability might be the change with highest potential for essential improvement. The expected cost reduction and finally contributing to this, the improvement of reliability including safe mission abort capability are driving this idea. Although there are ideas of semi-reusable launch vehicles, typically two stages vehicles - reusable first stage or booster(s) and expendable second or upper stage - it should be kept in mind that the benefit of reusability will only overwhelm if there is a big enough share influencing the cost calculation. Today there is the understanding that additional technology preparation and verification will be necessary to master reusability and get enough benefits compared with existing launch vehicles. This understanding is based on several technology and system concepts preparation and verification programmes mainly done in the US but partially also in Europe and Japan. The major areas of necessary further activities are: - System concepts including business plan considerations - Sub-system or component technologies refinement - System design and operation know-how and capabilities - Verification and demonstration oriented towards future mission mastering: One of the most important aspects for the creation of those coming programmes and activities will be the iterative process of requirements definition derived from concepts analyses including economical considerations and the results achieved and verified within technology and verification programmes. It is the intention of this paper to provide major trends for those requirements focused on future launch vehicles structures. This will include the aspects of requirements only valid for reusable launch vehicles and those common for expendable, semi-reusable and reusable launch vehicles. Structures and materials is and will be one of the important technology areas to be improved. This includes: - Primary structures - Thermal protection systems (for high and low temperatures) - Hot structures (leading edges, engine cowling, ...) - Tanks (for various propellants and fluids, cryo, ...) Requirements to be considered are including materials properties and a variety of loads definition - static and dynamic. Based on existing knowledge and experience for expendable LV (Ariane, ...) and aircraft there is the need to established a combined understanding to provide the basis for an efficient RLV design. Health monitoring will support the cost efficient operation of future reusable structures, but will also need a sound understanding of loads and failure mechanisms as basis. Risk mitigation will ask for several steps of demonstration towards a cost efficient RLV (structures) operation. Typically this has or will start with basic technology, to be evolved to components demonstration (TPS, tanks, ...) and finally to result in the demonstration of the cost efficient reuse operation. This paper will also include a programmatic logic concerning future LV structures demonstration.
PSEUDO-BINARY SYSTEMS INVOLVING RARE EARTH LAVES PHASES
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wernick, J.H.; Haszko, S.E.; Dorsi, D.
1962-06-01
The phase relations in a number of pseudo-binary systems involving rare earth Laves phases were determined. Complete series of cubic solid-solutions occur in the DyMn/sub 2/HoMn/sub 2/, HoMn/sub 2/-HoFe/sub 2/, DyMn/sub 2/-DyFe/ sub 2/, HoMn/sub 2/-HoAl/ sub 2/, TbMn/sub 2/TbAl/sub 2/, and DyMn/sub 2/-DyAl/ sub 2/ pseudobinary systems. Deviations from linearity in the lattice constants with composition occur in all these systems. Complete series of cubic solidsolutions also exist in the GdAl/sub 2/-ErAl/sub 2/, GdAl/sub 2/-PrAl/sub 2/ , GdAl/sub 2/-NdAl/sub 2/, GdAl/sub 2/-DyAl/sub 2/, TbAl/sub 2/-NdAl/sub 2/, and T bAl/sub 2/-DyAl/sub 2/ systems. For these systems, no deviation from linearitymore » occurs in the lattice constants. For the DyFe/sub 2/-DyAl/sub 2/ and DyCo/sub 2/- DyAl/sub 2/ systems, two new ternary phases, DyFeAl and DyCoAl, form and have the MgZn/sub 2/ structure. Their structures were determined from x-ray powder data only. The electronic state giving rise to the formation of these ternary phases is discussed qualitatively. For the DyMn/sub 2/TmMn/sub 2/ system, the range of composition in which the cubic MgCu/sub 2/ and hexagonal MgZn/sub 2/ structures exist are reported. No complete series of solid solutions or intermediate phases are formed in the DyNi/sub 2/-DyAl/sub 2/ system. (auth)« less
Semantic Analysis of Email Using Domain Ontologies and WordNet
NASA Technical Reports Server (NTRS)
Berrios, Daniel C.; Keller, Richard M.
2005-01-01
The problem of capturing and accessing knowledge in paper form has been supplanted by a problem of providing structure to vast amounts of electronic information. Systems that can construct semantic links for natural language documents like email messages automatically will be a crucial element of semantic email tools. We have designed an information extraction process that can leverage the knowledge already contained in an existing semantic web, recognizing references in email to existing nodes in a network of ontology instances by using linguistic knowledge and knowledge of the structure of the semantic web. We developed a heuristic score that uses several forms of evidence to detect references in email to existing nodes in the Semanticorganizer repository's network. While these scores cannot directly support automated probabilistic inference, they can be used to rank nodes by relevance and link those deemed most relevant to email messages.
Autonomous self-powered structural health monitoring system
NASA Astrophysics Data System (ADS)
Qing, Xinlin P.; Anton, Steven R.; Zhang, David; Kumar, Amrita; Inman, Daniel J.; Ooi, Teng K.
2010-03-01
Structural health monitoring technology is perceived as a revolutionary method of determining the integrity of structures involving the use of multidisciplinary fields including sensors, materials, system integration, signal processing and interpretation. The core of the technology is the development of self-sufficient systems for the continuous monitoring, inspection and damage detection of structures with minimal labor involvement. A major drawback of the existing technology for real-time structural health monitoring is the requirement for external electrical power input. For some applications, such as missiles or combat vehicles in the field, this factor can drastically limit the use of the technology. Having an on-board electrical power source that is independent of the vehicle power system can greatly enhance the SHM system and make it a completely self-contained system. In this paper, using the SMART layer technology as a basis, an Autonomous Self-powered (ASP) Structural Health Monitoring (SHM) system has been developed to solve the major challenge facing the transition of SHM systems into field applications. The architecture of the self-powered SHM system was first designed. There are four major components included in the SHM system: SMART Layer with sensor network, low power consumption diagnostic hardware, rechargeable battery with energy harvesting device, and host computer with supporting software. A prototype of the integrated self-powered active SHM system was built for performance and functionality testing. Results from the evaluation tests demonstrated that a fully charged battery system is capable of powering the SHM system for active scanning up to 10 hours.
An adaptive deep-coupled GNSS/INS navigation system with hybrid pre-filter processing
NASA Astrophysics Data System (ADS)
Wu, Mouyan; Ding, Jicheng; Zhao, Lin; Kang, Yingyao; Luo, Zhibin
2018-02-01
The deep-coupling of a global navigation satellite system (GNSS) with an inertial navigation system (INS) can provide accurate and reliable navigation information. There are several kinds of deeply-coupled structures. These can be divided mainly into coherent and non-coherent pre-filter based structures, which have their own strong advantages and disadvantages, especially in accuracy and robustness. In this paper, the existing pre-filters of the deeply-coupled structures are analyzed and modified to improve them firstly. Then, an adaptive GNSS/INS deeply-coupled algorithm with hybrid pre-filters processing is proposed to combine the advantages of coherent and non-coherent structures. An adaptive hysteresis controller is designed to implement the hybrid pre-filters processing strategy. The simulation and vehicle test results show that the adaptive deeply-coupled algorithm with hybrid pre-filters processing can effectively improve navigation accuracy and robustness, especially in a GNSS-challenged environment.
Seyed Moosavi, Seyed Mohsen; Moaveni, Bijan; Moshiri, Behzad; Arvan, Mohammad Reza
2018-02-27
The present study designed skewed redundant accelerometers for a Measurement While Drilling (MWD) tool and executed auto-calibration, fault diagnosis and isolation of accelerometers in this tool. The optimal structure includes four accelerometers was selected and designed precisely in accordance with the physical shape of the existing MWD tool. A new four-accelerometer structure was designed, implemented and installed on the current system, replacing the conventional orthogonal structure. Auto-calibration operation of skewed redundant accelerometers and all combinations of three accelerometers have been done. Consequently, biases, scale factors, and misalignment factors of accelerometers have been successfully estimated. By defecting the sensors in the new optimal skewed redundant structure, the fault was detected using the proposed FDI method and the faulty sensor was diagnosed and isolated. The results indicate that the system can continue to operate with at least three correct sensors.
Seyed Moosavi, Seyed Mohsen; Moshiri, Behzad; Arvan, Mohammad Reza
2018-01-01
The present study designed skewed redundant accelerometers for a Measurement While Drilling (MWD) tool and executed auto-calibration, fault diagnosis and isolation of accelerometers in this tool. The optimal structure includes four accelerometers was selected and designed precisely in accordance with the physical shape of the existing MWD tool. A new four-accelerometer structure was designed, implemented and installed on the current system, replacing the conventional orthogonal structure. Auto-calibration operation of skewed redundant accelerometers and all combinations of three accelerometers have been done. Consequently, biases, scale factors, and misalignment factors of accelerometers have been successfully estimated. By defecting the sensors in the new optimal skewed redundant structure, the fault was detected using the proposed FDI method and the faulty sensor was diagnosed and isolated. The results indicate that the system can continue to operate with at least three correct sensors. PMID:29495434
Classification framework for partially observed dynamical systems
NASA Astrophysics Data System (ADS)
Shen, Yuan; Tino, Peter; Tsaneva-Atanasova, Krasimira
2017-04-01
We present a general framework for classifying partially observed dynamical systems based on the idea of learning in the model space. In contrast to the existing approaches using point estimates of model parameters to represent individual data items, we employ posterior distributions over model parameters, thus taking into account in a principled manner the uncertainty due to both the generative (observational and/or dynamic noise) and observation (sampling in time) processes. We evaluate the framework on two test beds: a biological pathway model and a stochastic double-well system. Crucially, we show that the classification performance is not impaired when the model structure used for inferring posterior distributions is much more simple than the observation-generating model structure, provided the reduced-complexity inferential model structure captures the essential characteristics needed for the given classification task.
Detecting a liquid and solid H2O layer by geophysical methods
NASA Astrophysics Data System (ADS)
Yoshikawa, K.; Romanovsky, V.; Tsapin, A.; Brown, J.
2002-12-01
The objective is to detect the hydrological and cryological structure of the cold continuous permafrost subsurface using geophysical methods. We believe that a lot of water potentially exists as solid and liquid phases underground on Mars. It is likely that the liquid fluid would be high in saline concentration (brine). The ground freezing process involves many hydrological processes including enrichment of the brine layer. The brine layer is an important environment for ancient and/or current life to exist on terrestrial permafrost regions. The existence of a Martian brine layer would increase the possibility of the existence of life, as on Earth. In situ electric resistivity measurement will be the most efficient method to determine brine layer as well as massive H2O ice in the permafrost. However, the wiring configuration is unlikely to operate on the remote planetary surface. Satellite-born Radar and/or EM methods will be the most accessible methods for detecting the hydrological and cryological structure. We are testing several geophysical methods at the brine layer site in Barrow and massive pingo ice site in Fairbanks, Alaska. The radar system is affected by the dielectric properties of subsurface materials, which allows for evidence of liquid phase in the frozen ground. The dielectric constant varies greatly between liquid water and frozen ground. The depth of the terrestrial (and probably Martian) brine layer is frequently located deeper than the maximum detecting depth of the impulse type of the ground penetrating radar system. Once we develop a radar system with a deeper penetrating capability (Lower frequency), the dispersion of the ground ice will be the key function for interpretation of these signals. We will improve and use radar signals to understand the hydrological and cryological structure in the permafrost. The core samples and borehole temperature data validate these radar signals.
Three-dimensional hybrid grid generation using advancing front techniques
NASA Technical Reports Server (NTRS)
Steinbrenner, John P.; Noack, Ralph W.
1995-01-01
A new 3-dimensional hybrid grid generation technique has been developed, based on ideas of advancing fronts for both structured and unstructured grids. In this approach, structured grids are first generate independently around individual components of the geometry. Fronts are initialized on these structure grids, and advanced outward so that new cells are extracted directly from the structured grids. Employing typical advancing front techniques, cells are rejected if they intersect the existing front or fail other criteria When no more viable structured cells exist further cells are advanced in an unstructured manner to close off the overall domain, resulting in a grid of 'hybrid' form. There are two primary advantages to the hybrid formulation. First, generating blocks with limited regard to topology eliminates the bottleneck encountered when a multiple block system is used to fully encapsulate a domain. Individual blocks may be generated free of external constraints, which will significantly reduce the generation time. Secondly, grid points near the body (presumably with high aspect ratio) will still maintain a structured (non-triangular or tetrahedral) character, thereby maximizing grid quality and solution accuracy near the surface.
Quinn, Martha; Robinson, Claire; Forman, Jane; Krein, Sarah L; Rosland, Ann-Marie
2017-07-01
Improving access can increase the providers a patient sees, and cause coordination challenges. For initiatives that increase care across health care settings, measuring patient experiences with access and care coordination will be crucial. Map existing survey measures of patient experiences with access and care coordination expected to be relevant to patients accessing care across settings. Preliminarily examine whether aspects of access and care coordination important to patients are represented by existing measures. Structured literature review of domains and existing survey measures related to access and care coordination across settings. Survey measures, and preliminary themes from semistructured interviews of 10 patients offered VA-purchased Community Care, were mapped to identified domains. We identified 31 existing survey instruments with 279 items representing 6 access and 5 care coordination domains relevant to cross-system care. Domains frequently assessed by existing measures included follow-up coordination, primary care access, cross-setting coordination, and continuity. Preliminary issues identified in interviews, but not commonly assessed by existing measures included: (1) acceptability of distance to care site given patient's clinical situation; (2) burden on patients to access and coordinate care and billing; (3) provider familiarity with Veteran culture and VA processes. Existing survey instruments assess many aspects of patient experiences with access and care coordination in cross-system care. Systems assessing cross-system care should consider whether patient surveys accurately reflect the level of patients' concerns with burden to access and coordinate care, and adequately reflect the impact of clinical severity and cultural familiarity on patient preferences.
Neuronal pathway finding: from neurons to initial neural networks.
Roscigno, Cecelia I
2004-10-01
Neuronal pathway finding is crucial for structured cellular organization and development of neural circuits within the nervous system. Neuronal pathway finding within the visual system has been extensively studied and therefore is used as a model to review existing knowledge regarding concepts of this developmental process. General principles of neuron pathway finding throughout the nervous system exist. Comprehension of these concepts guides neuroscience nurses in gaining an understanding of the developmental course of action, the implications of different anomalies, as well as the theoretical basis and nursing implications of some provocative new therapies being proposed to treat neurodegenerative diseases and neurologic injuries. These therapies have limitations in light of current ethical, developmental, and delivery modes and what is known about the development of neuronal pathways.
Organization of the resting TCR in nanoscale oligomers.
Schamel, Wolfgang W A; Alarcón, Balbino
2013-01-01
Despite the low affinity of the T-cell antigen receptor (TCR) for its peptide/major histocompatibility complex (pMHC) ligand, T cells are very sensitive to their antigens. This paradox can be resolved if we consider that the TCR may be organized into pre-existing oligomers or nanoclusters. Such structures could improve antigen recognition by increasing the functional affinity (avidity) of the TCR-pMHC interaction and by allowing cooperativity between individual TCRs. Up to approximately 20 TCRs become tightly apposed in these nanoclusters, often in a linear manner, and such structures could reflect a relatively generalized phenomenon: the non-random concentration of membrane receptors in specific areas of the plasma membrane known as protein islands. The association of TCRs into nanoclusters can explain the enhanced kinetics of the pMHC-TCR interaction in two dimensional versus three dimensional systems, but also their existence calls for a revision of the TCR triggering models based on pMHC-induced TCR clustering. Interestingly, the B-cell receptor and the FcεRI have also been shown to form nanoclusters, suggesting that the formation of pre-existing receptor oligomers could be widely used in the immune system. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.
Conversion of a Temporary Tent with Steel Frame into a Permanent Warehouse
NASA Astrophysics Data System (ADS)
Georgescu, Mircea; Ungureanu, Viorel; Grecea, Daniel; Petran, Ioan
2017-10-01
The paper is dealing with the problem of a functional conversion (involving both architectural and structural issues) applied to the case of an industrial building. As well known, temporary tents, designed according to the European Code EN13782, represent a remarkable stake on the building market and a fast and practical solution for some situations. It is exactly the case approached by the paper, where the investor has initially decided to erect on his platform a provisional shelter for agricultural machines and subsequent staff, built of a light steel structure covered by PVC roofing and cladding. This temporary tent has been acquired from a specialized supplier in form of a series product. After using the tent for a number of years, the investor has decided to convert the existing structure from architectural and structural point of view by switching to a permanent structure designed accordingly. Important changes were thus imposed both to the architectural part (technological flows, openings, facades) and especially to the structural part where this switch imposed a re-design to the codes of permanent structures (especially as far as climatic loadings are concerned). The required architectural change implied the building of a 70 cm high concrete plinth and replacing the PVC membrane temporary roofing and cladding by permanent 60 mm thick PUR sandwich panels. Together with a new system of openings this has led to renewed facades of the buildings. As for the structural change, the required conversion has imposed a thorough checking of the existing steel structure (very slender and typical to a tent) in view of transforming it into a permanent structure. The consolidation measures of the existing galvanized steel structure are described, together with the measures applied at infrastructure level in order to implement the required conversion.
Kim, J H; Ferziger, R; Kawaloff, H B; Sands, D Z; Safran, C; Slack, W V
2001-01-01
Even the most extensive hospital information system cannot support all the complex and ever-changing demands associated with a clinical database, such as providing department or personal data forms, and rating scales. Well-designed clinical dialogue programs may facilitate direct interaction of patients with their medical records. Incorporation of extensive and loosely structured clinical data into an existing medical record system is an essential step towards a comprehensive clinical information system, and can best be achieved when the practitioner and the patient directly enter the contents. We have developed a rapid prototyping and clinical conversational system that complements the electronic medical record system, with its generic data structure and standard communication interfaces based on Web technology. We believe our approach can enhance collaboration between consumer-oriented and provider-oriented information systems.
Development of an embeddable reference electrode for reinforced concrete structures.
DOT National Transportation Integrated Search
1998-01-01
There is a concern that none of the existing concrete-embeddable reference electrodes that are being used as a convenient means for monitoring the condition of the reinforcing steel in concrete bridges or the operation of cathodic protection systems ...
Methods for estimating magnitude and frequency of peak flows for small watersheds in Utah.
DOT National Transportation Integrated Search
2010-06-01
Determining discharge in a stream is important to the design of culverts, bridges, and other structures pertaining to : transportation systems. Currently in Utah regression equations exist to estimate recurrence flood year discharges for : rural wate...
How to practice person-centred care: A conceptual framework.
Santana, Maria J; Manalili, Kimberly; Jolley, Rachel J; Zelinsky, Sandra; Quan, Hude; Lu, Mingshan
2018-04-01
Globally, health-care systems and organizations are looking to improve health system performance through the implementation of a person-centred care (PCC) model. While numerous conceptual frameworks for PCC exist, a gap remains in practical guidance on PCC implementation. Based on a narrative review of the PCC literature, a generic conceptual framework was developed in collaboration with a patient partner, which synthesizes evidence, recommendations and best practice from existing frameworks and implementation case studies. The Donabedian model for health-care improvement was used to classify PCC domains into the categories of "Structure," "Process" and "Outcome" for health-care quality improvement. The framework emphasizes the structural domain, which relates to the health-care system or context in which care is delivered, providing the foundation for PCC, and influencing the processes and outcomes of care. Structural domains identified include: the creation of a PCC culture across the continuum of care; co-designing educational programs, as well as health promotion and prevention programs with patients; providing a supportive and accommodating environment; and developing and integrating structures to support health information technology and to measure and monitor PCC performance. Process domains describe the importance of cultivating communication and respectful and compassionate care; engaging patients in managing their care; and integration of care. Outcome domains identified include: access to care and Patient-Reported Outcomes. This conceptual framework provides a step-wise roadmap to guide health-care systems and organizations in the provision PCC across various health-care sectors. © 2017 The Authors Health Expectations published by John Wiley & Sons Ltd.
Strengthening health systems by health sector reforms.
Senkubuge, Flavia; Modisenyane, Moeketsi; Bishaw, Tewabech
2014-01-01
The rising burden of disease and weak health systems are being compounded by the persistent economic downturn, re-emerging diseases, and violent conflicts. There is a growing recognition that the global health agenda needs to shift from an emphasis on disease-specific approaches to strengthening of health systems, including dealing with social, environmental, and economic determinants through multisectoral responses. A review and analysis of data on strengthening health sector reform and health systems was conducted. Attention was paid to the goal of health and interactions between health sector reforms and the functions of health systems. Further, we explored how these interactions contribute toward delivery of health services, equity, financial protection, and improved health. Health sector reforms cannot be developed from a single global or regional policy formula. Any reform will depend on the country's history, values and culture, and the population's expectations. Some of the emerging ingredients that need to be explored are infusion of a health systems agenda; development of a comprehensive policy package for health sector reforms; improving alignment of planning and coordination; use of reliable data; engaging 'street level' policy implementers; strengthening governance and leadership; and allowing a holistic and developmental approach to reforms. The process of reform needs a fundamental rather than merely an incremental and evolutionary change. Without radical structural and systemic changes, existing governance structures and management systems will continue to fail to address the existing health problems.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Certa, P.J.
1998-01-07
Readiness to Proceed With Phase 1B Privatization documents the processes used to determine readiness to proceed with tank waste treatment technologies from private industry, now known as TWRS privatization. An overall systems approach was applied to develop action plans to support the retrieval and disposal mission of the TWRS Project. The systems and infrastructure required to support the mission are known. Required systems are either in place or plans have been developed to ensure they exist when needed. Since October 1996 a robust system engineering approach to establishing integrated Technical Baselines, work breakdown structures, tank farms organizational structure and configurations,more » work scope, and costs has become part of the culture within the TWRS Project. An analysis of the programmatic, management, and technical activities necessary to declare readiness to proceed with execution of the mission demonstrates that the system, personnel, and hardware will be on line and ready to support the private contractors. The systems approach included defining the retrieval and disposal mission requirements and evaluating the readiness of the Project Hanford Management Contract (PHMC) team to support initiation of waste processing by the private contractors in June 2002 and to receive immobilized waste shortly thereafter. The Phase 1 feed delivery requirements from the private contractor Requests for Proposal were reviewed. Transfer piping routes were mapped, existing systems were evaluated, and upgrade requirements were defined.« less
Panjikar, Santosh; Parthasarathy, Venkataraman; Lamzin, Victor S; Weiss, Manfred S; Tucker, Paul A
2005-04-01
The EMBL-Hamburg Automated Crystal Structure Determination Platform is a system that combines a number of existing macromolecular crystallographic computer programs and several decision-makers into a software pipeline for automated and efficient crystal structure determination. The pipeline can be invoked as soon as X-ray data from derivatized protein crystals have been collected and processed. It is controlled by a web-based graphical user interface for data and parameter input, and for monitoring the progress of structure determination. A large number of possible structure-solution paths are encoded in the system and the optimal path is selected by the decision-makers as the structure solution evolves. The processes have been optimized for speed so that the pipeline can be used effectively for validating the X-ray experiment at a synchrotron beamline.
Zhou, Wengang; Dickerson, Julie A
2012-01-01
Knowledge of protein subcellular locations can help decipher a protein's biological function. This work proposes new features: sequence-based: Hybrid Amino Acid Pair (HAAP) and two structure-based: Secondary Structural Element Composition (SSEC) and solvent accessibility state frequency. A multi-class Support Vector Machine is developed to predict the locations. Testing on two established data sets yields better prediction accuracies than the best available systems. Comparisons with existing methods show comparable results to ESLPred2. When StruLocPred is applied to the entire Arabidopsis proteome, over 77% of proteins with known locations match the prediction results. An implementation of this system is at http://wgzhou.ece. iastate.edu/StruLocPred/.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hutton, Joe; Morgan, Huw, E-mail: joh9@aber.ac.uk
2015-11-01
The 3-part appearance of many coronal mass ejections (CMEs) arising from erupting filaments emerges from a large magnetic flux tube structure, consistent with the form of the erupting filament system. Other CMEs arising from erupting filaments lack a clear 3-part structure and reasons for this have not been researched in detail. This paper aims to further establish the link between CME structure and the structure of the erupting filament system and to investigate whether CMEs which lack a 3-part structure have different eruption characteristics. A survey is made of 221 near-limb filament eruptions observed from 2013 May 03 to 2014more » June 30 by Extreme UltraViolet (EUV) imagers and coronagraphs. Ninety-two filament eruptions are associated with 3-part structured CMEs, 41 eruptions are associated with unstructured CMEs. The remaining 88 are categorized as failed eruptions. For 34% of the 3-part CMEs, processing applied to EUV images reveals the erupting front edge is a pre-existing loop structure surrounding the filament, which subsequently erupts with the filament to form the leading bright front edge of the CME. This connection is confirmed by a flux-rope density model. Furthermore, the unstructured CMEs have a narrower distribution of mass compared to structured CMEs, with total mass comparable to the mass of 3-part CME cores. This study supports the interpretation of 3-part CME leading fronts as the outer boundaries of a large pre-existing flux tube. Unstructured (non 3-part) CMEs are a different family to structured CMEs, arising from the eruption of filaments which are compact flux tubes in the absence of a large system of enclosing closed field.« less
ERIC Educational Resources Information Center
Bozkurt, Ipek; Helm, James
2013-01-01
This paper develops a systems engineering-based framework to assist in the design of an online engineering course. Specifically, the purpose of the framework is to provide a structured methodology for the design, development and delivery of a fully online course, either brand new or modified from an existing face-to-face course. The main strength…
Federal Register 2010, 2011, 2012, 2013, 2014
2012-09-20
... consist of the following: (1) An existing 32-foot-high, 3500-foot-long earth filled dam; (2) a reservoir... bypass channel; (4) a 65-foot-wide, 35- foot-long intake structure with a trash rack cleaning system; (5... system at http://www.ferc.gov/docs-filing/ecomment.asp . You must include your name and contact...
USDA-ARS?s Scientific Manuscript database
In the US there is a sudden increase in the need for cage-free eggs in retail and food manufacturing sectors. As the US industry adapts existing and builds new cage-free housing structures, there is a need to understand the impact of cage-free systems and the corresponding management on egg quality...
Nonlinear Light Dynamics in Multi-Core Structures
2017-02-27
be generated in continuous- discrete optical media such as multi-core optical fiber or waveguide arrays; localisation dynamics in a continuous... discrete nonlinear system. Detailed theoretical analysis is presented of the existence and stability of the discrete -continuous light bullets using a very...and pulse compression using wave collapse (self-focusing) energy localisation dynamics in a continuous- discrete nonlinear system, as implemented in a
A classification system for predicting pallet part quality from hardwood cants
E. Paul Craft; Kenneth R., Jr. Whitenack
1982-01-01
Producers who manufacture pallet parts from hardwood cants generally must purchase cants on the basis of existing structural timber grades that do not adequately reflect the quality of pallet parts produced from resawed cants. A system for classifying cants for pallet part production has been developed that more accurately reflects the parts grade mix that can be...
Learning Sequential Composition Control.
Najafi, Esmaeil; Babuska, Robert; Lopes, Gabriel A D
2016-11-01
Sequential composition is an effective supervisory control method for addressing control problems in nonlinear dynamical systems. It executes a set of controllers sequentially to achieve a control specification that cannot be realized by a single controller. As these controllers are designed offline, sequential composition cannot address unmodeled situations that might occur during runtime. This paper proposes a learning approach to augment the standard sequential composition framework by using online learning to handle unforeseen situations. New controllers are acquired via learning and added to the existing supervisory control structure. In the proposed setting, learning experiments are restricted to take place within the domain of attraction (DOA) of the existing controllers. This guarantees that the learning process is safe (i.e., the closed loop system is always stable). In addition, the DOA of the new learned controller is approximated after each learning trial. This keeps the learning process short as learning is terminated as soon as the DOA of the learned controller is sufficiently large. The proposed approach has been implemented on two nonlinear systems: 1) a nonlinear mass-damper system and 2) an inverted pendulum. The results show that in both cases a new controller can be rapidly learned and added to the supervisory control structure.
An E-payment system based on quantum group signature
NASA Astrophysics Data System (ADS)
Xiaojun, Wen
2010-12-01
Security and anonymity are essential to E-payment systems. However, existing E-payment systems will easily be broken into soon with the emergence of quantum computers. In this paper, we propose an E-payment system based on quantum group signature. In contrast to classical E-payment systems, our quantum E-payment system can protect not only the users' anonymity but also the inner structure of customer groups. Because of adopting the two techniques of quantum key distribution, a one-time pad and quantum group signature, unconditional security of our E-payment system is guaranteed.
NASA Technical Reports Server (NTRS)
Mcguirk, James P.
1990-01-01
Satellite data analysis tools are developed and implemented for the diagnosis of atmospheric circulation systems over the tropical Pacific Ocean. The tools include statistical multi-variate procedures, a multi-spectral radiative transfer model, and the global spectral forecast model at NMC. Data include in-situ observations; satellite observations from VAS (moisture, infrared and visible) NOAA polar orbiters (including Tiros Operational Satellite System (TOVS) multi-channel sounding data and OLR grids) and scanning multichannel microwave radiometer (SMMR); and European Centre for Medium Weather Forecasts (ECHMWF) analyses. A primary goal is a better understanding of the relation between synoptic structures of the area, particularly tropical plumes, and the general circulation, especially the Hadley circulation. A second goal is the definition of the quantitative structure and behavior of all Pacific tropical synoptic systems. Finally, strategies are examined for extracting new and additional information from existing satellite observations. Although moisture structure is emphasized, thermal patterns are also analyzed. Both horizontal and vertical structures are studied and objective quantitative results are emphasized.
Databases, Repositories and Other Data Resources in Structural Biology
Zheng, Heping; Porebski, Przemyslaw J.; Grabowski, Marek; Cooper, David R.; Minor, Wladek
2017-01-01
Structural biology, like many other areas of modern science, produces an enormous amount of primary, derived, and “meta” data with a high demand on data storage and manipulations. Primary data comes from various steps of sample preparation, diffraction experiments, and functional studies. These data are not only used to obtain tangible results, like macromolecular structural models, but also to enrich and guide our analysis and interpretation of existing biomedical studies. Herein we define several categories of data resources, (a) Archives, (b) Repositories, (c) “Databases” and (d) Advanced Information Systems, that can accommodate primary, derived, or reference data. Data resources may be used either as web portals or internally by structural biology software. To be useful, each resource must be maintained, curated, and be integrated with other resources. Ideally, the system of interconnected resources should evolve toward comprehensive “hubs” or Advanced Information Systems. Such systems, encompassing the PDB and UniProt, are indispensable not only for structural biology, but for many related fields of science. The categories of data resources described herein are applicable well beyond our usual scientific endeavors. PMID:28573593
Complex networks as an emerging property of hierarchical preferential attachment.
Hébert-Dufresne, Laurent; Laurence, Edward; Allard, Antoine; Young, Jean-Gabriel; Dubé, Louis J
2015-12-01
Real complex systems are not rigidly structured; no clear rules or blueprints exist for their construction. Yet, amidst their apparent randomness, complex structural properties universally emerge. We propose that an important class of complex systems can be modeled as an organization of many embedded levels (potentially infinite in number), all of them following the same universal growth principle known as preferential attachment. We give examples of such hierarchy in real systems, for instance, in the pyramid of production entities of the film industry. More importantly, we show how real complex networks can be interpreted as a projection of our model, from which their scale independence, their clustering, their hierarchy, their fractality, and their navigability naturally emerge. Our results suggest that complex networks, viewed as growing systems, can be quite simple, and that the apparent complexity of their structure is largely a reflection of their unobserved hierarchical nature.
Complex networks as an emerging property of hierarchical preferential attachment
NASA Astrophysics Data System (ADS)
Hébert-Dufresne, Laurent; Laurence, Edward; Allard, Antoine; Young, Jean-Gabriel; Dubé, Louis J.
2015-12-01
Real complex systems are not rigidly structured; no clear rules or blueprints exist for their construction. Yet, amidst their apparent randomness, complex structural properties universally emerge. We propose that an important class of complex systems can be modeled as an organization of many embedded levels (potentially infinite in number), all of them following the same universal growth principle known as preferential attachment. We give examples of such hierarchy in real systems, for instance, in the pyramid of production entities of the film industry. More importantly, we show how real complex networks can be interpreted as a projection of our model, from which their scale independence, their clustering, their hierarchy, their fractality, and their navigability naturally emerge. Our results suggest that complex networks, viewed as growing systems, can be quite simple, and that the apparent complexity of their structure is largely a reflection of their unobserved hierarchical nature.
Achievable flatness in a large microwave power transmitting antenna
NASA Technical Reports Server (NTRS)
Ried, R. C.
1980-01-01
A dual reference SPS system with pseudoisotropic graphite composite as a representative dimensionally stable composite was studied. The loads, accelerations, thermal environments, temperatures and distortions were calculated for a variety of operational SPS conditions along with statistical considerations of material properties, manufacturing tolerances, measurement accuracy and the resulting loss of sight (LOS) and local slope distributions. A LOS error and a subarray rms slope error of two arc minutes can be achieved with a passive system. Results show that existing materials measurement, manufacturing, assembly and alignment techniques can be used to build the microwave power transmission system antenna structure. Manufacturing tolerance can be critical to rms slope error. The slope error budget can be met with a passive system. Structural joints without free play are essential in the assembly of the large truss structure. Variations in material properties, particularly for coefficient of thermal expansion from part to part, is more significant than actual value.
Emergency in-flight egress opening for general aviation aircraft
NASA Technical Reports Server (NTRS)
Bement, L. J.
1980-01-01
In support of a stall/spin research program, an emergency in-flight egress system is being installed in a light general aviation airplane. To avoid a major structural redesign for a mechanical door, an add-on 11.2 kg pyrotechnic-actuated system was developed to create an opening in the existing structure. The airplane skin will be explosively severed around the side window, across a central stringer, and down to the floor, creating an opening of approximately 76 by 76 cm. The severed panel will be jettisoned at an initial velocity of approximately 13.7 m/sec. System development included a total of 68 explosive severance tests on aluminum material using small samples, small and full scale flat panel aircraft structural mock-ups, and an actual aircraft fuselage. These tests proved explosive sizing/severance margins, explosive initiation, explosive product containment, and system dynamics.
Leveraging natural dynamical structures to explore multi-body systems
NASA Astrophysics Data System (ADS)
Bosanac, Natasha
Multi-body systems have become the target of an increasing number of mission concepts and observations, supplying further information about the composition, origin and dynamical environment of bodies within the solar system and beyond. In many of these scenarios, identification and characterization of the particular solutions that exist in a circular restricted three-body model is valuable. This insight into the underlying natural dynamical structures is achieved via the application of dynamical systems techniques. One application of such analysis is trajectory design for CubeSats, which are intended to explore cislunar space and other planetary systems. These increasingly complex mission objectives necessitate innovative trajectory design strategies for spacecraft within our solar system, as well as the capability for rapid and well-informed redesign. Accordingly, a trajectory design framework is constructed using dynamical systems techniques and demonstrated for the Lunar IceCube mission. An additional application explored in this investigation involves the motion of an exoplanet near a binary star system. Due to the strong gravitational field near a binary star, physicists have previously leveraged these systems as testbeds for examining the validity of gravitational and relativistic theories. In this investigation, a preliminary analysis into the effect of an additional three-body interaction on the dynamical environment near a large mass ratio binary system is conducted. As demonstrated through both of these sample applications, identification and characterization of the natural particular solutions that exist within a multi-body system supports a well-informed and guided analysis.
Winkelman, Warren J.; Leonard, Kevin J.
2004-01-01
There are constraints embedded in medical record structure that limit use by patients in self-directed disease management. Through systematic review of the literature from a critical perspective, four characteristics that either enhance or mitigate the influence of medical record structure on patient utilization of an electronic patient record (EPR) system have been identified: environmental pressures, physician centeredness, collaborative organizational culture, and patient centeredness. An evaluation framework is proposed for use when considering adaptation of existing EPR systems for online patient access. Exemplars of patient-accessible EPR systems from the literature are evaluated utilizing the framework. From this study, it appears that traditional information system research and development methods may not wholly capture many pertinent social issues that arise when expanding access of EPR systems to patients. Critically rooted methods such as action research can directly inform development strategies so that these systems may positively influence health outcomes. PMID:14633932
Non-contact tensile viscoelastic characterization of microscale biological materials
NASA Astrophysics Data System (ADS)
Li, Yuhui; Hong, Yuan; Xu, Guang-Kui; Liu, Shaobao; Shi, Qiang; Tang, Deding; Yang, Hui; Genin, Guy M.; Lu, Tian Jian; Xu, Feng
2018-06-01
Many structures and materials in nature and physiology have important "meso-scale" structures at the micron length-scale whose tensile responses have proven difficult to characterize mechanically. Although techniques such as atomic force microscopy and micro- and nano-identation are mature for compression and indentation testing at the nano-scale, and standard uniaxial and shear rheometry techniques exist for the macroscale, few techniques are applicable for tensile-testing at the micrometre-scale, leaving a gap in our understanding of hierarchical biomaterials. Here, we present a novel magnetic mechanical testing (MMT) system that enables viscoelastic tensile testing at this critical length scale. The MMT system applies non-contact loading, avoiding gripping and surface interaction effects. We demonstrate application of the MMT system to the first analyses of the pure tensile responses of several native and engineered tissue systems at the mesoscale, showing the broad potential of the system for exploring micro- and meso-scale analysis of structured and hierarchical biological systems.
Non-contact tensile viscoelastic characterization of microscale biological materials
NASA Astrophysics Data System (ADS)
Li, Yuhui; Hong, Yuan; Xu, Guang-Kui; Liu, Shaobao; Shi, Qiang; Tang, Deding; Yang, Hui; Genin, Guy M.; Lu, Tian Jian; Xu, Feng
2018-01-01
Many structures and materials in nature and physiology have important "meso-scale" structures at the micron length-scale whose tensile responses have proven difficult to characterize mechanically. Although techniques such as atomic force microscopy and micro- and nano-identation are mature for compression and indentation testing at the nano-scale, and standard uniaxial and shear rheometry techniques exist for the macroscale, few techniques are applicable for tensile-testing at the micrometre-scale, leaving a gap in our understanding of hierarchical biomaterials. Here, we present a novel magnetic mechanical testing (MMT) system that enables viscoelastic tensile testing at this critical length scale. The MMT system applies non-contact loading, avoiding gripping and surface interaction effects. We demonstrate application of the MMT system to the first analyses of the pure tensile responses of several native and engineered tissue systems at the mesoscale, showing the broad potential of the system for exploring micro- and meso-scale analysis of structured and hierarchical biological systems.
Nolte, Tom M; Ragas, Ad M J
2017-03-22
Many organic chemicals are ionizable by nature. After use and release into the environment, various fate processes determine their concentrations, and hence exposure to aquatic organisms. In the absence of suitable data, such fate processes can be estimated using Quantitative Structure-Property Relationships (QSPRs). In this review we compiled available QSPRs from the open literature and assessed their applicability towards ionizable organic chemicals. Using quantitative and qualitative criteria we selected the 'best' QSPRs for sorption, (a)biotic degradation, and bioconcentration. The results indicate that many suitable QSPRs exist, but some critical knowledge gaps remain. Specifically, future focus should be directed towards the development of QSPR models for biodegradation in wastewater and sediment systems, direct photolysis and reaction with singlet oxygen, as well as additional reactive intermediates. Adequate QSPRs for bioconcentration in fish exist, but more accurate assessments can be achieved using pharmacologically based toxicokinetic (PBTK) models. No adequate QSPRs exist for bioconcentration in non-fish species. Due to the high variability of chemical and biological species as well as environmental conditions in QSPR datasets, accurate predictions for specific systems and inter-dataset conversions are problematic, for which standardization is needed. For all QSPR endpoints, additional data requirements involve supplementing the current chemical space covered and accurately characterizing the test systems used.
Simulation of charge transfer and orbital rehybridization in molecular and condensed matter systems
NASA Astrophysics Data System (ADS)
Nistor, Razvan A.
The mixing and shifting of electronic orbitals in molecules, or between atoms in bulk systems, is crucially important to the overall structure and physical properties of materials. Understanding and accurately modeling these orbital interactions is of both scientific and industrial relevance. Electronic orbitals can be perturbed in several ways. Doping, adding or removing electrons from systems, can change the bond-order and the physical properties of certain materials. Orbital rehybridization, driven by either thermal or pressure excitation, alters the short-range structure of materials and changes their long-range transport properties. Macroscopically, during bond formation, the shifting of electronic orbitals can be interpreted as a charge transfer phenomenon, as electron density may pile up around, and hence, alter the effective charge of, a given atom in the changing chemical environment. Several levels of theory exist to elucidate the mechanisms behind these orbital interactions. Electronic structure calculations solve the time-independent Schrodinger equation to high chemical accuracy, but are computationally expensive and limited to small system sizes and simulation times. Less fundamental atomistic calculations use simpler parameterized functional expressions called force-fields to model atomic interactions. Atomistic simulations can describe systems and time-scales larger and longer than electronic-structure methods, but at the cost of chemical accuracy. In this thesis, both first-principles and phenomenological methods are addressed in the study of several encompassing problems dealing with charge transfer and orbital rehybridization. Firstly, a new charge-equilibration method is developed that improves upon existing models to allow next-generation force-fields to describe the electrostatics of changing chemical environments. Secondly, electronic structure calculations are used to investigate the doping dependent energy landscapes of several high-temperature superconducting materials in order to parameterize the apparently large nonlinear electron-phonon coupling. Thirdly, ab initio simulations are used to investigate the role of pressure-driven structural re-organization in the crystalline-to-amorphous (or, metallic-to-insulating) transition of a common binary phase-change material composed of Ge and Sb. Practical applications of each topic will be discussed. Keywords. Charge-equilibration methods, molecular dynamics, electronic structure calculations, ab initio simulations, high-temperature superconductors, phase-change materials.
47 CFR 17.17 - Existing structures.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 47 Telecommunication 1 2010-10-01 2010-10-01 false Existing structures. 17.17 Section 17.17... STRUCTURES Federal Aviation Administration Notification Criteria § 17.17 Existing structures. (a) The requirements found in § 17.23 relating to painting and lighting of antenna structures shall not apply to those...
NASA Astrophysics Data System (ADS)
Pachla, Henryk
2017-12-01
The idea of strengthening the foundation using injection piles lies in transferring loads from the foundation to the piles anchorage in existing structure and formed in the soil. Such a system has to be able to transfer loads from the foundation to the pile and from the pile onto the soil. Pile structure often reinforced with steel element has to also be able to transfer such a loading. According to the rules of continuum mechanics, the bearing capacity of such a system and a deformation of its individual elements can be determined by way of an analysis of the contact problem of three interfaces. Each of these surfaces is determined by different couples of materials. Those surfaces create: pile-foundation anchorage, bonding between reinforcement and material from which the pile is formed and pilesoil interface. What is essential is that on the contact surfaces the deformation of materials which adhere to each other can vary and depends on the mechanical properties and geometry of these surfaces. Engineering practice and experimental research point out that the failure in such structures occurs at interfaces. The paper is concentrating on presenting the experiments on interaction between cement grout and various types of steel reinforcement. The tests were conducted on the special low pressure injection piles widely used to strengthen foundations of already existing structures of historical buildings due to the technology of formation and injection pressure.
Force on Force Modeling with Formal Task Structures and Dynamic Geometry
2017-03-24
task framework, derived using the MMF methodology to structure a complex mission. It further demonstrated the integration of effects from a range of...application methodology was intended to support a combined developmental testing (DT) and operational testing (OT) strategy for selected systems under test... methodology to develop new or modify existing Models and Simulations (M&S) to: • Apply data from multiple, distributed sources (including test
Tele-existence and/or cybernetic interface studies in Japan
NASA Technical Reports Server (NTRS)
Tachi, Susumu
1991-01-01
Tele-existence aims at a natural and efficient remote control of robots by providing the operator with a real time sensation of presence. It is an advaced type of teleoperation system which enables a human operator at the controls to perform remote manipulation tasks dexterously with the feeling that he or she exists in one of the remote anthropomorphic robots in the remote environment, e.g., in a hostile environment such as those of nuclear radiation, high temperature, and deep space. In order to study the use of the tele-existence system in the artificially constructed environment, the visual tele-existence simulator has been designed, a pseudo-real-time binocular solid model robot simulator has been made, and its feasibility has been experimentally evaluated. An anthropomorphic robot mechanism with an arm having seven degrees of freedom has been designed and developed as a slave robot for feasibility experiments of teleoperation using the tele-existence method. An impedance controlled active display mechanism and a head mounted display have also been designed and developed as the display subsystem for the master. The robot's structural dimensions are set very close to those of humans.
NASA Astrophysics Data System (ADS)
Abbasbandy, S.; Van Gorder, R. A.; Hajiketabi, M.; Mesrizadeh, M.
2015-10-01
We consider traveling wave solutions to the Casimir equation for the Ito system (a two-field extension of the KdV equation). These traveling waves are governed by a nonlinear initial value problem with an interesting nonlinearity (which actually amplifies in magnitude as the size of the solution becomes small). The nonlinear problem is parameterized by two initial constant values, and we demonstrate that the existence of solutions is strongly tied to these parameter values. For our interests, we are concerned with positive, bounded, periodic wave solutions. We are able to classify parameter regimes which admit such solutions in full generality, thereby obtaining a nice existence result. Using the existence result, we are then able to numerically simulate the positive, bounded, periodic solutions. We elect to employ a group preserving scheme in order to numerically study these solutions, and an outline of this approach is provided. The numerical simulations serve to illustrate the properties of these solutions predicted analytically through the existence result. Physically, these results demonstrate the existence of a type of space-periodic structure in the Casimir equation for the Ito model, which propagates as a traveling wave.
A CONCEPTUAL MODEL FOR MULTI-SCALAR ASSESSMENTS OF ESTUARINE ECOLOGICAL INTEGRITY
A conceptual model was developed that relates an estuarine system's anthropogenic inputs to it's ecological integrity. Ecological integrity is operationally defined as an emergent property of an ecosystem that exists when the structural components are complete and the functional ...
Longitudinal Joint Repair Best Practices for the Ohio Department of Transportation
DOT National Transportation Integrated Search
2017-07-01
The Ohio Department of Transportation (ODOT) has identified longitudinal joint (LJ) failure of existing hot-mix asphalt (HMA) paving as a systemic weakness in the structure of some asphalt surfaces. In the past, these joint failures were treated as i...
Adaptive neural network/expert system that learns fault diagnosis for different structures
NASA Astrophysics Data System (ADS)
Simon, Solomon H.
1992-08-01
Corporations need better real-time monitoring and control systems to improve productivity by watching quality and increasing production flexibility. The innovative technology to achieve this goal is evolving in the form artificial intelligence and neural networks applied to sensor processing, fusion, and interpretation. By using these advanced Al techniques, we can leverage existing systems and add value to conventional techniques. Neural networks and knowledge-based expert systems can be combined into intelligent sensor systems which provide real-time monitoring, control, evaluation, and fault diagnosis for production systems. Neural network-based intelligent sensor systems are more reliable because they can provide continuous, non-destructive monitoring and inspection. Use of neural networks can result in sensor fusion and the ability to model highly, non-linear systems. Improved models can provide a foundation for more accurate performance parameters and predictions. We discuss a research software/hardware prototype which integrates neural networks, expert systems, and sensor technologies and which can adapt across a variety of structures to perform fault diagnosis. The flexibility and adaptability of the prototype in learning two structures is presented. Potential applications are discussed.
NASA Technical Reports Server (NTRS)
Hanks, Brantley R.; Skelton, Robert E.
1991-01-01
This paper addresses the restriction of Linear Quadratic Regulator (LQR) solutions to the algebraic Riccati Equation to design spaces which can be implemented as passive structural members and/or dampers. A general closed-form solution to the optimal free-decay control problem is presented which is tailored for structural-mechanical systems. The solution includes, as subsets, special cases such as the Rayleigh Dissipation Function and total energy. Weighting matrix selection is a constrained choice among several parameters to obtain desired physical relationships. The closed-form solution is also applicable to active control design for systems where perfect, collocated actuator-sensor pairs exist. Some examples of simple spring mass systems are shown to illustrate key points.
A cross-diffusion system derived from a Fokker-Planck equation with partial averaging
NASA Astrophysics Data System (ADS)
Jüngel, Ansgar; Zamponi, Nicola
2017-02-01
A cross-diffusion system for two components with a Laplacian structure is analyzed on the multi-dimensional torus. This system, which was recently suggested by P.-L. Lions, is formally derived from a Fokker-Planck equation for the probability density associated with a multi-dimensional Itō process, assuming that the diffusion coefficients depend on partial averages of the probability density with exponential weights. A main feature is that the diffusion matrix of the limiting cross-diffusion system is generally neither symmetric nor positive definite, but its structure allows for the use of entropy methods. The global-in-time existence of positive weak solutions is proved and, under a simplifying assumption, the large-time asymptotics is investigated.
NASA Astrophysics Data System (ADS)
Demina, Maria V.
2018-05-01
The general structure of irreducible invariant algebraic curves for a polynomial dynamical system in C2 is found. Necessary conditions for existence of exponential factors related to an invariant algebraic curve are derived. As a consequence, all the cases when the classical force-free Duffing and Duffing-van der Pol oscillators possess Liouvillian first integrals are obtained. New exact solutions for the force-free Duffing-van der Pol system are constructed.
Global stability and quadratic Hamiltonian structure in Lotka-Volterra and quasi-polynomial systems
NASA Astrophysics Data System (ADS)
Szederkényi, Gábor; Hangos, Katalin M.
2004-04-01
We show that the global stability of quasi-polynomial (QP) and Lotka-Volterra (LV) systems with the well-known logarithmic Lyapunov function is equivalent to the existence of a local generalized dissipative Hamiltonian description of the LV system with a diagonal quadratic form as a Hamiltonian function. The Hamiltonian function can be calculated and the quadratic dissipativity neighborhood of the origin can be estimated by solving linear matrix inequalities.
Structural Similitude and Scaling Laws
NASA Technical Reports Server (NTRS)
Simitses, George J.
1998-01-01
Aircraft and spacecraft comprise the class of aerospace structures that require efficiency and wisdom in design, sophistication and accuracy in analysis and numerous and careful experimental evaluations of components and prototype, in order to achieve the necessary system reliability, performance and safety. Preliminary and/or concept design entails the assemblage of system mission requirements, system expected performance and identification of components and their connections as well as of manufacturing and system assembly techniques. This is accomplished through experience based on previous similar designs, and through the possible use of models to simulate the entire system characteristics. Detail design is heavily dependent on information and concepts derived from the previous steps. This information identifies critical design areas which need sophisticated analyses, and design and redesign procedures to achieve the expected component performance. This step may require several independent analysis models, which, in many instances, require component testing. The last step in the design process, before going to production, is the verification of the design. This step necessitates the production of large components and prototypes in order to test component and system analytical predictions and verify strength and performance requirements under the worst loading conditions that the system is expected to encounter in service. Clearly then, full-scale testing is in many cases necessary and always very expensive. In the aircraft industry, in addition to full-scale tests, certification and safety necessitate large component static and dynamic testing. Such tests are extremely difficult, time consuming and definitely absolutely necessary. Clearly, one should not expect that prototype testing will be totally eliminated in the aircraft industry. It is hoped, though, that we can reduce full-scale testing to a minimum. Full-scale large component testing is necessary in other industries as well, Ship building, automobile and railway car construction all rely heavily on testing. Regardless of the application, a scaled-down (by a large factor) model (scale model) which closely represents the structural behavior of the full-scale system (prototype) can prove to be an extremely beneficial tool. This possible development must be based on the existence of certain structural parameters that control the behavior of a structural system when acted upon by static and/or dynamic loads. If such structural parameters exist, a scaled-down replica can be built, which will duplicate the response of the full-scale system. The two systems are then said to be structurally similar. The term, then, that best describes this similarity is structural similitude. Similarity of systems requires that the relevant system parameters be identical and these systems be governed by a unique set of characteristic equations. Thus, if a relation or equation of variables is written for a system, it is valid for all systems which are similar to it. Each variable in a model is proportional to the corresponding variable of the prototype. This ratio, which plays an essential role in predicting the relationship between the model and its prototype, is called the scale factor.
Han, Yafeng; Shen, Bo; Hu, Huajin; ...
2015-01-12
Ice-storage air-conditioning is a technique that uses ice for thermal energy storage. Replacing existing air conditioning systems with ice storage has the advantage of shifting the load from on-peak times to off-peak times that often have excess generation. However, increasing the use of ice-storage faces significant challenges in China. One major barrier is the inefficiency in the current electricity tariff structure. There is a lack of effective incentive mechanism that induces ice-storage systems from achieving optimal load-shifting results. This study presents an analysis that compares the potential impacts of ice-storage systems on load-shifting under a new credit-based incentive scheme andmore » the existing incentive arrangement in Jiangsu, China. The study indicates that by changing how ice-storage systems are incentivized in Jiangsu, load-shifting results can be improved.« less
Green Turning Brown - Domain Engineering for Social and Health Services in Finland.
Suomi, Reima; Nykänen, Pirkko; Vepsäläinen, Tapio; Hiltunen, Riina
2017-01-01
Being able to design information systems to an untouched domain, without the burden of existing information systems, especially legacy systems, is often seen as a dream of most information system professionals. Uncharted domains are anyway scarce, and often such greenfield projects turn into brownfield projects, also to projects where existing structures severely constrain the development of new systems. In this article we discuss the concepts of greenfield and brownfield domain engineering and software development, and reflect their possible messages to the re-engineering of the Finnish health- and social care ecosystem currently under way. In our fieldwork we could identify a lot of need and wish for greenfield domain engineering in the Finnish health and social services delivery. As well we found a lot of brownfield elements inhibiting change. Our proposal for the future is a ecosystem approach, where new and established elements could live together in a self-governed balance.
Scaling laws for light-weight optics
NASA Technical Reports Server (NTRS)
Valente, Tina M.
1990-01-01
Scaling laws for light-weight optical systems are examined. A cubic relationship between mirror diameter and weight has been suggested and used by many designers of optical systems as the best description for all light-weight mirrors. A survey of existing light-weight systems in the open literature has been made to clarify this issue. Fifty existing optical systems were surveyed with all varieties of light-weight mirrors including glass and beryllium structured mirrors, contoured mirrors, and very thin solid mirrors. These mirrors were then categorized and weight to diameter ratio was plotted to find a best fit curve for each case. A best fitting curve program tests nineteen different equations and ranks a 'goodness of fit' for each of these equations. The resulting relationship found for each light-weight mirror category helps to quantify light-weight optical systems and methods of fabrication and provides comparisons between mirror types.
Multiscale structure of time series revealed by the monotony spectrum.
Vamoş, Călin
2017-03-01
Observation of complex systems produces time series with specific dynamics at different time scales. The majority of the existing numerical methods for multiscale analysis first decompose the time series into several simpler components and the multiscale structure is given by the properties of their components. We present a numerical method which describes the multiscale structure of arbitrary time series without decomposing them. It is based on the monotony spectrum defined as the variation of the mean amplitude of the monotonic segments with respect to the mean local time scale during successive averagings of the time series, the local time scales being the durations of the monotonic segments. The maxima of the monotony spectrum indicate the time scales which dominate the variations of the time series. We show that the monotony spectrum can correctly analyze a diversity of artificial time series and can discriminate the existence of deterministic variations at large time scales from the random fluctuations. As an application we analyze the multifractal structure of some hydrological time series.
Global Existence Results for Viscoplasticity at Finite Strain
NASA Astrophysics Data System (ADS)
Mielke, Alexander; Rossi, Riccarda; Savaré, Giuseppe
2018-01-01
We study a model for rate-dependent gradient plasticity at finite strain based on the multiplicative decomposition of the strain tensor, and investigate the existence of global-in-time solutions to the related PDE system. We reveal its underlying structure as a generalized gradient system, where the driving energy functional is highly nonconvex and features the geometric nonlinearities related to finite-strain elasticity as well as the multiplicative decomposition of finite-strain plasticity. Moreover, the dissipation potential depends on the left-invariant plastic rate, and thus depends on the plastic state variable. The existence theory is developed for a class of abstract, nonsmooth, and nonconvex gradient systems, for which we introduce suitable notions of solutions, namely energy-dissipation-balance and energy-dissipation-inequality solutions. Hence, we resort to the toolbox of the direct method of the calculus of variations to check that the specific energy and dissipation functionals for our viscoplastic models comply with the conditions of the general theory.
Understanding congestion in China's medical market: an incentive structure perspective.
Sun, Zesheng; Wang, Shuhong; Barnes, Stephen R
2016-04-01
Congestion has become one of the most important factors leading to patient dissatisfaction and doctor-patient conflicts in the medical market of China. In this study, we explore the causes and effects of structural congestion in the Chinese medical market from an incentive structure perspective. Our analysis reveals that prior medical system reforms with price regulation in China have induced hospitals to establish incentives for capital-intensive investments, while ignoring human capital, and have driven medical staff and patients to higher-level hospitals, reinforcing an incentive structure in which congestion in higher-level hospitals and idle resources in lower-level hospitals coexist. The existing incentive structure has led to cost increases and degradation of human capital and specific factor effects. Recent reforms to reduce congestion in the Chinese medical market were not effective. Most of them had no impact on and did not involve the existing distorted incentive structure. Future reforms should consider rebalancing expectations for medical quality, free flow of human capital and price regulation reforms to rebuild a new incentive structure. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.
Advances in structural monitoring with Global Positioning System technology: 1997-2006
NASA Astrophysics Data System (ADS)
Ogaja, Clement; Li, Xiaojing; Rizos, Chris
2007-11-01
Over the last decade, users of the Global Positioning System (GPS) have developed the technology capable of meeting stringent requirements to study the dynamics of tall buildings, towers, and bridges during earthquakes, wind-induced deformation and traffic loading. Dynamic measurements of relative displacements of structures is currently possible using real-time kinematic (RTK) positioning techniques, now advanced to record typically at 10-20 Hz (or higher - e.g., 100 Hz) with an accuracy of ±1 cm horizontally and ±2 cm vertically. With further advances in the technology and improvements in sampling capability, it is possible to meet the needs of real-time displacement information for the structural engineering community. After a decade of great strides in proving the feasibility of the technology, focus is moving to sensor integration and operational systems. Several investigators are now routinely researching the integration of GPS with other sensors (accelerometers, fibre optics, pseudolites, etc.) to utilise the complementary benefits and overcome limitations of the individual systems. Examples of real-time operational systems exist to demonstrate the significance of GPS technology in measuring the dynamic behaviour of large engineering structures.
NASA Technical Reports Server (NTRS)
Hanks, Brantley R.; Skelton, Robert E.
1991-01-01
Vibration in modern structural and mechanical systems can be reduced in amplitude by increasing stiffness, redistributing stiffness and mass, and/or adding damping if design techniques are available to do so. Linear Quadratic Regulator (LQR) theory in modern multivariable control design, attacks the general dissipative elastic system design problem in a global formulation. The optimal design, however, allows electronic connections and phase relations which are not physically practical or possible in passive structural-mechanical devices. The restriction of LQR solutions (to the Algebraic Riccati Equation) to design spaces which can be implemented as passive structural members and/or dampers is addressed. A general closed-form solution to the optimal free-decay control problem is presented which is tailored for structural-mechanical system. The solution includes, as subsets, special cases such as the Rayleigh Dissipation Function and total energy. Weighting matrix selection is a constrained choice among several parameters to obtain desired physical relationships. The closed-form solution is also applicable to active control design for systems where perfect, collocated actuator-sensor pairs exist.
Characterization of structural connections using free and forced response test data
NASA Technical Reports Server (NTRS)
Lawrence, Charles; Huckelbridge, Arthur A.
1989-01-01
The accurate prediction of system dynamic response often has been limited by deficiencies in existing capabilities to characterize connections adequately. Connections between structural components often are complex mechanically, and difficult to accurately model analytically. Improved analytical models for connections are needed to improve system dynamic preditions. A procedure for identifying physical connection properties from free and forced response test data is developed, then verified utilizing a system having both a linear and nonlinear connection. Connection properties are computed in terms of physical parameters so that the physical characteristics of the connections can better be understood, in addition to providing improved input for the system model. The identification procedure is applicable to multi-degree of freedom systems, and does not require that the test data be measured directly at the connection locations.
Singh, Satendra Pal; Kim, Minseuk; Park, Woon Bae; Lee, Jin-Woong; Sohn, Kee-Sun
2016-10-17
A solid-state combinatorial chemistry approach, which used the A-Ge-O (A = Li, K, Rb) system doped with a small amount of Mn 4+ as an activator, was adopted in a search for novel red-emitting phosphors. The A site may have been composed of either a single alkali metal ion or of a combination of them. This approach led to the discovery of a novel phosphor in the above system with the chemical formula Li 3 RbGe 8 O 18 :Mn 4+ . The crystal structure of this novel phosphor was solved via direct methods, and subsequent Rietveld refinement revealed a trigonal structure in the P3̅1m space group. The discovered phosphor is believed to be novel in the sense that neither the crystal structure nor the chemical formula matches any of the prototype structures available in the crystallographic information database (ICDD or ICSD). The measured photoluminescence intensity that peaked at a wavelength of 667 nm was found to be much higher than the best intensity obtained among all the existing A 2 Ge 4 O 9 (A = Li, K, Rb) compounds in the alkali-germanate system. An ab initio calculation based on density function theory (DFT) was conducted to verify the crystal structure model and compare the calculated value of the optical band gap with the experimental results. The optical band gap obtained from diffuse reflectance measurement (5.26 eV) and DFT calculation (4.64 eV) results were in very good agreement. The emission wavelength of this phosphor that exists in the deep red region of the electromagnetic spectrum may be very useful for increasing the color gamut of LED-based display devices such as ultrahigh-definition television (UHDTV) as per the ITU-R BT.2020-2 recommendations and also for down-converter phosphors that are used in solar-cell applications.
Biomimetic structural engineering of P22 virus-like particles for catalysis and immune modulation
NASA Astrophysics Data System (ADS)
Schwarz, Benjamin
Within biology molecules are arranged in hierarchical structures that coordinate and control the many processes that allow for complex organisms to exist. Proteins and other functional macromolecules are often studied outside their natural nanostructural context because it remains difficult to create controlled arrangements of proteins at this size scale. Viruses are elegantly simple nano-systems that exist at the interface of living organisms and non-living biological machines. Studied and viewed primarily as pathogens to be combatted, viruses have emerged as models of structural efficiency at the nanoscale and have spurred the development of biomimetic nanoparticle systems. Virus-like particles (VLPs) are noninfectious protein cages derived from viruses or other cage-forming systems. VLPs provide incredibly regular scaffolds for building at the nanoscale. In this work I have utilized the VLP derived from the bacteriophage P22 as a platform for the organization of enzymes, antigens, and immune-stimulating proteins inside and outside the capsid through purely genetic means. In the case of enzymes, encapsulation of a two-enzyme pathway has led to the development of metabolic nanoparticle catalysts and an expanded understanding of the control that structure exerts on metabolic flux. These same structural elements applied to the delivery of protein subunit antigens directed at cytotoxic T cell immunity result in drastically enhanced antigen processing and lasting immunological memory. Lastly, presentation of immune-stimulating proteins from the Tumor Necrosis Factor Super Family on the surface of the P22 VLP enhances the cell signaling efficiency of these compounds 50-fold and provides strategies for the application of these proteins as immune modulatory oncology therapeutics. In all of these cases, the reintroduction of nanostructure to these protein systems, reminiscent of their natural environment, has led to both new technologies and a better understanding of the role of structure in biological processes.
Urban Planning and Management Information Systems Analysis and Design Based on GIS
NASA Astrophysics Data System (ADS)
Xin, Wang
Based on the analysis of existing relevant systems on the basis of inadequate, after a detailed investigation and research, urban planning and management information system will be designed for three-tier structure system, under the LAN using C/S mode architecture. Related functions for the system designed in accordance with the requirements of the architecture design of the functional relationships between the modules. Analysis of the relevant interface and design, data storage solutions proposed. The design for small and medium urban planning information system provides a viable building program.
Visualization of reservoir simulation data with an immersive virtual reality system
DOE Office of Scientific and Technical Information (OSTI.GOV)
Williams, B.K.
1996-10-01
This paper discusses an investigation into the use of an immersive virtual reality (VR) system to visualize reservoir simulation output data. The hardware and software configurations of the test-immersive VR system are described and compared to a nonimmersive VR system and to an existing workstation screen-based visualization system. The structure of 3D reservoir simulation data and the actions to be performed on the data within the VR system are discussed. The subjective results of the investigation are then presented, followed by a discussion of possible future work.
NASA Astrophysics Data System (ADS)
Bellahsen, N.; Leroy, S.; Autin, J.; Razin, P.; d'Acremont, E.; Sloan, H.; Pik, R.; Ahmed, A.; Khanbari, K.
2013-11-01
Transfer zones are ubiquitous features in continental rifts and margins, as are transform faults in oceanic lithosphere. Here, we present a structural study of the Hadibo Transfer Zone (HTZ), located in Socotra Island (Yemen) in the southeastern Gulf of Aden. There, we interpret this continental transfer fault zone to represent a reactivated pre-existing structure. Its trend is oblique to the direction of divergence and it has been active from the early up to the latest stages of rifting. One of the main oceanic fracture zones (FZ), the Hadibo-Sharbithat FZ, is aligned with and appears to be an extension of the HTZ and is probably genetically linked to it. Comparing this setting with observations from other Afro-Arabian rifts as well as with passive margins worldwide, it appears that many continental transfer zones are reactivated pre-existing structures, oblique to divergence. We therefore establish a classification system for oceanic FZ based upon their relationship with syn-rift structures. Type 1 FZ form at syn-rift structures and are late syn-rift to early syn-OCT. Type 2 FZ form during the OCT formation and Type 3 FZ form within the oceanic domain, after the oceanic spreading onset. The latter are controlled by far-field forces, magmatic processes, spreading rates, and oceanic crust rheology.
A model structure for an EBM program in a multihospital system.
Schumacher, Dale N; Stock, Joseph R; Richards, Joan K
2003-01-01
Evidence-based medicine (EBM) offers a great opportunity to translate advances in medical science into advances in clinical practice. We describe the structure of a comprehensive EBM program in a multihospital community teaching system. This EBM model is distinct and separate from the peer review process and has achieved substantial physician involvement. The program emanates from the Board of Directors Quality of Care Committee and has strong administrative support. The approach relies extensively on physician involvement and expert physician panels to enhance existing EBM practice guidelines, with an explicit strategy of performance reports and feedback.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-21
...NMFS publishes regulations to implement Amendment 86 to the Fishery Management Plan for Groundfish of the Bering Sea and Aleutian Islands Management Area and Amendment 76 to the Fishery Management Plan for Groundfish of the Gulf of Alaska (Amendments 86/76). Amendments 86/ 76 add a funding and deployment system for observer coverage to the existing North Pacific Groundfish Observer Program (Observer Program) and amend existing observer coverage requirements for vessels and processing plants. The new funding and deployment system allows NMFS to determine when and where to deploy observers according to management and conservation needs, with funds provided through a system of fees based on the ex-vessel value of groundfish and halibut in fisheries covered by the new system. This action is necessary to resolve data quality and cost equity concerns with the Observer Program's existing funding and deployment structure. This action is intended to promote the goals and objectives of the Magnuson-Stevens Fishery Conservation and Management Act, the Northern Pacific Halibut Act of 1982, the fishery management plans, and other applicable law.
Systematic analysis of EOS data system for operations
NASA Technical Reports Server (NTRS)
Moe, K. L.; Dasgupta, R.
1985-01-01
A data management analysis methodology is being proposed. The objective of the methodology is to assist mission managers by identifying a series of ordered activities to be systematically followed in order to arrive at an effective ground system design. Existing system engineering tools and concepts have been assembled into a structured framework to facilitate the work of a mission planner. It is intended that this methodology can be gainfully applied (with probable modifications and/or changes) to the EOS payloads and their associated data systems.
NASA Astrophysics Data System (ADS)
Ji, Yunguang; Xu, Yangyang; Li, Hongtao; Oklejas, Michael; Xue, Shuqi
2018-01-01
A new type of hydraulic turbocharger energy recovery system was designed and applied in the decarbonisation process by propylene carbonate of a 100k tons ammonia synthesis system firstly in China. Compared with existing energy recovery devices, hydraulic turbocharger energy recovery system runs more smoothly, has lower failure rate, longer service life and greater comprehensive benefits due to its unique structure, simpler adjustment process and better adaptability to fluid fluctuation.
Preparation and measurement of FBG-based length, temperature, and vibration sensors
NASA Astrophysics Data System (ADS)
Mikel, Bretislav; Helan, Radek; Buchta, Zdenek; Jelinek, Michal; Cip, Ondrej
2016-12-01
We present system of structure health measurement by optical fiber sensors based on fiber Bragg gratings. Our system is focused to additionally install to existing buildings. We prepared first set-up of the system to monitoring of the nuclear power plant containment shape deformation. The presented system can measure up to several tens of sensors simultaneously. Each sensor contains optical fiber grating to measurement of change of length and the other independed fiber grating to monitor the temperature and the other ineligible effects.
Analysis of structural response data using discrete modal filters. M.S. Thesis
NASA Technical Reports Server (NTRS)
Freudinger, Lawrence C.
1991-01-01
The application of reciprocal modal vectors to the analysis of structural response data is described. Reciprocal modal vectors are constructed using an existing experimental modal model and an existing frequency response matrix of a structure, and can be assembled into a matrix that effectively transforms the data from the physical space to a modal space within a particular frequency range. In other words, the weighting matrix necessary for modal vector orthogonality (typically the mass matrix) is contained within the reciprocal model matrix. The underlying goal of this work is mostly directed toward observing the modal state responses in the presence of unknown, possibly closed loop forcing functions, thus having an impact on both operating data analysis techniques and independent modal space control techniques. This study investigates the behavior of reciprocol modal vectors as modal filters with respect to certain calculation parameters and their performance with perturbed system frequency response data.
Impact of cell size on inventory and mapping errors in a cellular geographic information system
NASA Technical Reports Server (NTRS)
Wehde, M. E. (Principal Investigator)
1979-01-01
The author has identified the following significant results. The effect of grid position was found insignificant for maps but highly significant for isolated mapping units. A modelable relationship between mapping error and cell size was observed for the map segment analyzed. Map data structure was also analyzed with an interboundary distance distribution approach. Map data structure and the impact of cell size on that structure were observed. The existence of a model allowing prediction of mapping error based on map structure was hypothesized and two generations of models were tested under simplifying assumptions.
Hamiltonian dynamics for complex food webs
NASA Astrophysics Data System (ADS)
Kozlov, Vladimir; Vakulenko, Sergey; Wennergren, Uno
2016-03-01
We investigate stability and dynamics of large ecological networks by introducing classical methods of dynamical system theory from physics, including Hamiltonian and averaging methods. Our analysis exploits the topological structure of the network, namely the existence of strongly connected nodes (hubs) in the networks. We reveal new relations between topology, interaction structure, and network dynamics. We describe mechanisms of catastrophic phenomena leading to sharp changes of dynamics and hence completely altering the ecosystem. We also show how these phenomena depend on the structure of interaction between species. We can conclude that a Hamiltonian structure of biological interactions leads to stability and large biodiversity.
BRST theory without Hamiltonian and Lagrangian
NASA Astrophysics Data System (ADS)
Lyakhovich, S. L.; Sharapov, A. A.
2005-03-01
We consider a generic gauge system, whose physical degrees of freedom are obtained by restriction on a constraint surface followed by factorization with respect to the action of gauge transformations; in so doing, no Hamiltonian structure or action principle is supposed to exist. For such a generic gauge system we construct a consistent BRST formulation, which includes the conventional BV Lagrangian and BFV Hamiltonian schemes as particular cases. If the original manifold carries a weak Poisson structure (a bivector field giving rise to a Poisson bracket on the space of physical observables) the generic gauge system is shown to admit deformation quantization by means of the Kontsevich formality theorem. A sigma-model interpretation of this quantization algorithm is briefly discussed.
NASA Astrophysics Data System (ADS)
Brylina, O. G.; Osintsev, K. V.; Prikhodko, YU S.; Savosteenko, N. V.
2018-03-01
The article considers the issues of energy technological complexes economy increase on the existing techniques of water-coal suspensions preparation and burning basis due to application of highly effective control systems of electric drives and neurocontrol. The automated control system structure for the main boiler components is given. The electric drive structure is disclosed by the example of pumps (for transfer of coal-water mash and / or suspension). A system for controlling and diagnosing a heat and power complex based on a multi-zone regulator is proposed. The possibility of using neural networks for implementing the control algorithms outlined in the article is considered.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Martin, Mark A.
2002-04-16
Vegetation Management along the Rocky Reach – Maple Valley No. 1 Transmission Line ROW from structure 98/2 to structure 110/1. The transmission line is a 500 kV line. BPA proposes to clear targeted vegetation along access roads and around tower structures that may impede the operation and maintenance of the subject transmission line. BPA plans to conduct vegetation management along existing access road and around structure landings for the purpose of maintaining access to structures site. All work will be in accordance with the National Electrical Safety Code and BPA standards.
Fibrin network changes in neonates after cardiopulmonary bypass
Brown, Ashley C.; Hannan, Riley; Timmins, Lucas H.; Fernandez, Janet D.; Barker, Thomas H.; Guzzetta, Nina A.
2016-01-01
Background Quantitative and qualitative differences exist between the hemostatic systems of neonates and adults, among them the presence of ‘fetal’ fibrinogen, a qualitatively dysfunctional form of fibrinogen that exists until one year of age. The consequences of ‘fetal’ fibrinogen on clot structure in neonates, particularly in the context of surgical associated bleeding, have not been well characterized. Here we examine the sequential changes in clotting components and resultant clot structure in a small sample of neonates undergoing cardiac surgery and cardiopulmonary bypass (CPB). Methods Blood samples were collected from neonates (n=10) before surgery, immediately after CPB and following the transfusion of cryoprecipitate (i.e. adult fibrinogen component). Clots were formed from patient samples or purified neonatal and adult fibrinogen. Clot structure was analyzed using confocal microscopy. Results Clots formed from plasma obtained after CPB and after transfusion were more porous than baseline clots. Analysis of clots formed from purified neonatal and adult fibrinogen, demonstrated that at equivalent fibrinogen concentrations, neonatal clots lack three-dimensional structure while adult clots were denser with significant three-dimensional structure. Clots formed from a combination of purified neonatal and adult fibrinogen were less homogenous than those formed from either purified adult or neonatal fibrinogen. Conclusions Our results confirm that significant differences exist in clot structure between neonates and adults, and that neonatal and adult fibrinogen may not integrate well. These findings suggest that differential treatment strategies for neonates should be pursued to reduce the demonstrated morbidity of blood product transfusion. PMID:26914227
Enhancement/upgrade of Engine Structures Technology Best Estimator (EST/BEST) Software System
NASA Technical Reports Server (NTRS)
Shah, Ashwin
2003-01-01
This report describes the work performed during the contract period and the capabilities included in the EST/BEST software system. The developed EST/BEST software system includes the integrated NESSUS, IPACS, COBSTRAN, and ALCCA computer codes required to perform the engine cycle mission and component structural analysis. Also, the interactive input generator for NESSUS, IPACS, and COBSTRAN computer codes have been developed and integrated with the EST/BEST software system. The input generator allows the user to create input from scratch as well as edit existing input files interactively. Since it has been integrated with the EST/BEST software system, it enables the user to modify EST/BEST generated files and perform the analysis to evaluate the benefits. Appendix A gives details of how to use the newly added features in the EST/BEST software system.
A structured vocabulary for indexing dietary supplements in databases in the United States
USDA-ARS?s Scientific Manuscript database
Food composition databases are critical to assess and plan dietary intakes. Dietary supplement databases are also needed because dietary supplements make significant contributions to total nutrient intakes. However, no uniform system exists for classifying dietary supplement products and indexing ...
Poisson structure of dynamical systems with three degrees of freedom
NASA Astrophysics Data System (ADS)
Gümral, Hasan; Nutku, Yavuz
1993-12-01
It is shown that the Poisson structure of dynamical systems with three degrees of freedom can be defined in terms of an integrable one-form in three dimensions. Advantage is taken of this fact and the theory of foliations is used in discussing the geometrical structure underlying complete and partial integrability. Techniques for finding Poisson structures are presented and applied to various examples such as the Halphen system which has been studied as the two-monopole problem by Atiyah and Hitchin. It is shown that the Halphen system can be formulated in terms of a flat SL(2,R)-valued connection and belongs to a nontrivial Godbillon-Vey class. On the other hand, for the Euler top and a special case of three-species Lotka-Volterra equations which are contained in the Halphen system as limiting cases, this structure degenerates into the form of globally integrable bi-Hamiltonian structures. The globally integrable bi-Hamiltonian case is a linear and the SL(2,R) structure is a quadratic unfolding of an integrable one-form in 3+1 dimensions. It is shown that the existence of a vector field compatible with the flow is a powerful tool in the investigation of Poisson structure and some new techniques for incorporating arbitrary constants into the Poisson one-form are presented herein. This leads to some extensions, analogous to q extensions, of Poisson structure. The Kermack-McKendrick model and some of its generalizations describing the spread of epidemics, as well as the integrable cases of the Lorenz, Lotka-Volterra, May-Leonard, and Maxwell-Bloch systems admit globally integrable bi-Hamiltonian structure.
NASA Astrophysics Data System (ADS)
Krämer, Sebastian G. M.; Wiesent, Benjamin; Müller, Mathias S.; Puente León, Fernando; Méndez Hernández, Yarú
2008-04-01
Wind turbine blades are made of composite materials and reach a length of more than 42 meters. Developments for modern offshore turbines are working on about 60 meters long blades. Hence, with the increasing height of the turbines and the remote locations of the structures, health monitoring systems are becoming more and more important. Therefore, fiber-optic sensor systems are well-suited, as they are lightweight, immune against electromagnetic interference (EMI), and as they can be multiplexed. Based on two separately existing concepts for strain measurements and lightning detection on wind turbines, a fused system is presented. The strain measurement system is based on a reflective fiber-Bragg-grating (FBG) network embedded in the composite structure of the blade. For lightning detection, transmissive &fiber-optic magnetic field sensors based on the Faraday effect are used to register the lightning parameters and estimate the impact point. Hence, an existing lightning detection system will be augmented, due to the fusion, by the capability to measure strain, temperature and vibration. Load, strain, temperature and impact detection information can be incorporated into the turbine's monitoring or SCADA system and remote controlled by operators. Data analysis techniques allow dynamic maintenance scheduling to become a reality, what is of special interest for the cost-effective maintenance of large offshore or badly attainable onshore wind parks. To prove the feasibility of this sensor fusion on one optical fiber, interferences between both sensor systems are investigated and evaluated.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Honeyman, J.O.
1998-01-09
This Management Assessment of Tank Waste Remediation System (TWRS) Contractor Readiness to Proceed With Phase 1B Privatization documents the processes used to determine readiness to proceed with tank waste treatment technologies from private industry, now known as TWRS privatization. An overall systems approach was applied to develop action plans to support the retrieval and disposal mission of the TWRS Project. The systems and infrastructure required to support the mission are known. Required systems are either in place or plans have been developed to ensure they exist when needed. Since October 1996 a robust system engineering approach to establishing integrated Technicalmore » Baselines, work breakdown structures, tank farms organizational structure and configurations, work scope, and costs has become part of the culture within the TWRS Project. An analysis of the programmatic, management, and technical activities necessary to declare readiness to proceed with execution of the mission demonstrates that the system, personnel, and hardware will be on-line and ready to support the private contractors. The systems approach included defining the retrieval and disposal mission requirements and evaluating the readiness of the Project Hanford Management Contract (PHMC) team to support initiation of waste processing by the private contractors in June 2002 and to receive immobilized waste shortly thereafter. The Phase 1 feed delivery requirements from the private contractor Requests for Proposal were reviewed. Transfer piping routes were mapped, existing systems were evaluated, and upgrade requirements were defined.« less
Study of synthesis techniques for insensitive aircraft control systems
NASA Technical Reports Server (NTRS)
Harvey, C. A.; Pope, R. E.
1977-01-01
Insensitive flight control system design criteria was defined in terms of maximizing performance (handling qualities, RMS gust response, transient response, stability margins) over a defined parameter range. Wing load alleviation for the C-5A was chosen as a design problem. The C-5A model was a 79-state, two-control structure with uncertainties assumed to exist in dynamic pressure, structural damping and frequency, and the stability derivative, M sub w. Five new techniques (mismatch estimation, uncertainty weighting, finite dimensional inverse, maximum difficulty, dual Lyapunov) were developed. Six existing techniques (additive noise, minimax, multiplant, sensitivity vector augmentation, state dependent noise, residualization) and the mismatch estimation and uncertainty weighting techniques were synthesized and evaluated on the design example. Evaluation and comparison of these six techniques indicated that the minimax and the uncertainty weighting techniques were superior to the other six, and of these two, uncertainty weighting has lower computational requirements. Techniques based on the three remaining new concepts appear promising and are recommended for further research.
NASA Astrophysics Data System (ADS)
Hsu, Sze-Bi; Mei, Linfeng; Wang, Feng-Bin
2015-11-01
Phytoplankton species in a water column compete for mineral nutrients and light, and the existing models usually neglect differences in the nutrient content and the amount of light absorbed of individuals. In this current paper, we examine a size-structured and nonlocal reaction-diffusion-advection system which describes the dynamics of a single phytoplankton species in a water column where the species depends simply on light for its growth. Our model is under the assumption that the amount of light absorbed by individuals is proportional to cell size, which varies for populations that reproduce by simple division into two equally-sized daughters. We first establish the existence of a critical death rate and our analysis indicates that the phytoplankton survives if and only if its death rate is less than the critical death rate. The critical death rate depends on a general reproductive rate, the characteristics of the water column (e.g., turbulent diffusion rate, sinking, depth), cell growth, cell division, and cell size.
Payment changes require integrating records.
Palley, M A
1990-06-01
The greatest challenges for healthcare organizations facing radical changes in their payment and reporting structures lie in finding ways to integrate various forms of patient information. An analysis of how three New York City hospitals dealt with their state's switch to an all-payer diagnosis related group-based payment system reveals strengths and weaknesses in their existing information systems and in steps taken to adapt to the change.
ERIC Educational Resources Information Center
Dustrud, Stephanine A. Martin
2012-01-01
Power is embedded within all aspects of human experience and has been a fundamental constituent in social systems since the beginning of recorded history. Power exists in every organization and evolves as the culture of the organization exerts its influence. Organizational structures and systems dictate the elements of power, its use, and its…
Gaussian maximally multipartite-entangled states
NASA Astrophysics Data System (ADS)
Facchi, Paolo; Florio, Giuseppe; Lupo, Cosmo; Mancini, Stefano; Pascazio, Saverio
2009-12-01
We study maximally multipartite-entangled states in the context of Gaussian continuous variable quantum systems. By considering multimode Gaussian states with constrained energy, we show that perfect maximally multipartite-entangled states, which exhibit the maximum amount of bipartite entanglement for all bipartitions, only exist for systems containing n=2 or 3 modes. We further numerically investigate the structure of these states and their frustration for n≤7 .
Research directions in large scale systems and decentralized control
NASA Technical Reports Server (NTRS)
Tenney, R. R.
1980-01-01
Control theory provides a well established framework for dealing with automatic decision problems and a set of techniques for automatic decision making which exploit special structure, but it does not deal well with complexity. The potential exists for combining control theoretic and knowledge based concepts into a unified approach. The elements of control theory are diagrammed, including modern control and large scale systems.
ERIC Educational Resources Information Center
Yeboah, Amy Oppong
2013-01-01
From great African nations like the Ancient Kemites, Akan and Gikuyu, the world witnessed the development of the most powerful social structures, governance systems, ground breaking innovations in science and technology, and systems of thought that still exist today. Hence, in looking at the low performance levels of Black students today, the…
Variable Structure PID Control to Prevent Integrator Windup
NASA Technical Reports Server (NTRS)
Hall, C. E.; Hodel, A. S.; Hung, J. Y.
1999-01-01
PID controllers are frequently used to control systems requiring zero steady-state error while maintaining requirements for settling time and robustness (gain/phase margins). PID controllers suffer significant loss of performance due to short-term integrator wind-up when used in systems with actuator saturation. We examine several existing and proposed methods for the prevention of integrator wind-up in both continuous and discrete time implementations.
Anomalous structural transition of confined hard squares.
Gurin, Péter; Varga, Szabolcs; Odriozola, Gerardo
2016-11-01
Structural transitions are examined in quasi-one-dimensional systems of freely rotating hard squares, which are confined between two parallel walls. We find two competing phases: one is a fluid where the squares have two sides parallel to the walls, while the second one is a solidlike structure with a zigzag arrangement of the squares. Using transfer matrix method we show that the configuration space consists of subspaces of fluidlike and solidlike phases, which are connected with low probability microstates of mixed structures. The existence of these connecting states makes the thermodynamic quantities continuous and precludes the possibility of a true phase transition. However, thermodynamic functions indicate strong tendency for the phase transition and our replica exchange Monte Carlo simulation study detects several important markers of the first order phase transition. The distinction of a phase transition from a structural change is practically impossible with simulations and experiments in such systems like the confined hard squares.
Strengthening of bridges by post-tensioning using monostrands in substituted cable ducts
NASA Astrophysics Data System (ADS)
Klusáček, Ladislav; Svoboda, Adam
2017-09-01
Post-tensioning is suitable, reliable and durable method of strengthening existing engineering structures, especially bridges. The high efficiency of post-tensioning can be seen in many applications throughout the world. In this paper the method is extended by a structural system of substituted cable ducts, which allows for significantly widening application of prestressing so it’s convenient mostly for application on beam bridges or slab bridges (built in years 1920 - 1960). The method of substituted cable ducts is based on theoretical knowledge and technical procedures, which were made possible through the development in prestressing systems, particularly the development of prestressing tendons (monostrands) and encased anchorages, as well as progress in drilling technology. This technique is highly recommended due to minimization of interventions into the constructions, unseen method of cable arrangement and hence the absence of impact on appearance, which is appreciated not only in case of valuable historical structures but also in general. It is possible to summarise that posttensioning by monostrands in substituted cable ducts is a highly effective method of strengthening existing bridges in order to increase their load capacities in terms of current traffic load and to extend their service life.
Vector data structure conversion at the EROS Data Center
van Roessel, Jan W.; Doescher, S.W.
1986-01-01
With the increasing prevalence of GIS systems and the processing of spatial data, conversion of data from one system to another has become a more serious problem. This report describes the approach taken to arrive at a solution at the EROS Data Center. The report consists of a main section and a number of appendices. The methodology is described in the main section, while the appendices have system specific descriptions. The overall approach is based on a central conversion hub consisting of a relational database manager and associated tools, with a standard data structure for the transfer of spatial data. This approach is the best compromise between the two goals of reducing the overall interfacing effort and producing efficient system interfaces, while the tools can be used to arrive at a progression of interface sophistication ranging from toolbench to smooth flow. The appendices provide detailed information on a number of spatial data handling systems and data structures and existing interfaces as well as interfaces developed with the described methodology.
76 FR 1861 - Privacy Act of 1974: Republication of Notice of Systems of Records
Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-11
...In accordance with 5 U.S.C. 552a(e)(4), the Tennessee Valley Authority (TVA) is republishing in full a notice of the existence and character of each TVA system of records. TVA is deleting one system of records because the program has ended. The retention period for the records has expired and the records have been destroyed in accordance with their records retention schedule. TVA is proposing to add a new system of records. The records were previously included within other TVA systems of records. They are now being published as their own system of records to better reflect their organizational placement. TVA is also correcting minor typographical and stylistic errors in previously existing notices and has updated those notices to reflect current organizational structure. Also, updates are being made to show any changes to system locations; managers and addresses; categories of individuals and records; procedures and practices for storing, retrieving, accessing, retaining, and disposing of records.
NASA Astrophysics Data System (ADS)
Zhou, Renjie; So, Peter T. C.; Yaqoob, Zahid; Jin, Di; Hosseini, Poorya; Kuang, Cuifang; Singh, Vijay Raj; Kim, Yang-Hyo; Dasari, Ramachandra R.
2017-02-01
Most of the quantitative phase microscopy systems are unable to provide depth-resolved information for measuring complex biological structures. Optical diffraction tomography provides a non-trivial solution to it by 3D reconstructing the object with multiple measurements through different ways of realization. Previously, our lab developed a reflection-mode dynamic speckle-field phase microscopy (DSPM) technique, which can be used to perform depth resolved measurements in a single shot. Thus, this system is suitable for measuring dynamics in a layer of interest in the sample. DSPM can be also used for tomographic imaging, which promises to solve the long-existing "missing cone" problem in 3D imaging. However, the 3D imaging theory for this type of system has not been developed in the literature. Recently, we have developed an inverse scattering model to rigorously describe the imaging physics in DSPM. Our model is based on the diffraction tomography theory and the speckle statistics. Using our model, we first precisely calculated the defocus response and the depth resolution in our system. Then, we further calculated the 3D coherence transfer function to link the 3D object structural information with the axially scanned imaging data. From this transfer function, we found that in the reflection mode excellent sectioning effect exists in the low lateral spatial frequency region, thus allowing us to solve the "missing cone" problem. Currently, we are working on using this coherence transfer function to reconstruct layered structures and complex cells.
Mejía, Sol M; Espinal, Juan F; Mills, Matthew J L; Mondragón, Fanor
2016-08-01
Bioethanol is one of the world's most extensively produced biofuels. However, it is difficult to purify due to the formation of the ethanol-water azeotrope. Knowledge of the azeotrope structure at the molecular level can help to improve existing purification methods. In order to achieve a better understanding of this azeotrope structure, the characterization of (ethanol)5-water heterohexamers was carried out by analyzing the results of electronic structure calculations performed at the B3LYP/6-31+G(d) level. Hexamerization energies were found to range between -36.8 and -25.8 kcal/mol. Topological analysis of the electron density confirmed the existence of primary (OH…O) hydrogen bonds (HBs), secondary (CH…O) HBs, and H…H interactions in these clusters. Comparison with three different solvated alcohol systems featuring the same types of atom-atom interactions permitted the following order of stability to be determined: (methanol)5-water > (methanol)6 > (ethanol)5-water > (ethanol)6. These findings, together with accompanying geometric and spectroscopic analyses, show that similar cooperative effects exist among the primary HBs for structures with the same arrangement of primary HBs, regardless of the nature of the molecules involved. This result provides an indication that the molecular ratio can be considered to determine the unusual behavior of the ethanol-water system. The investigation also highlights the presence of several types of weak interaction in addition to primary HBs. Graphical Abstract Water-ethanol clusters exhibit a variety of interaction types between their atoms, such as primary OH...O (blue), secondary CH...O (green) and H...H (yellow) interactions as revealed by Quantum Chemical Topology.
Physical approach to complex systems
NASA Astrophysics Data System (ADS)
Kwapień, Jarosław; Drożdż, Stanisław
2012-06-01
Typically, complex systems are natural or social systems which consist of a large number of nonlinearly interacting elements. These systems are open, they interchange information or mass with environment and constantly modify their internal structure and patterns of activity in the process of self-organization. As a result, they are flexible and easily adapt to variable external conditions. However, the most striking property of such systems is the existence of emergent phenomena which cannot be simply derived or predicted solely from the knowledge of the systems’ structure and the interactions among their individual elements. This property points to the holistic approaches which require giving parallel descriptions of the same system on different levels of its organization. There is strong evidence-consolidated also in the present review-that different, even apparently disparate complex systems can have astonishingly similar characteristics both in their structure and in their behaviour. One can thus expect the existence of some common, universal laws that govern their properties. Physics methodology proves helpful in addressing many of the related issues. In this review, we advocate some of the computational methods which in our opinion are especially fruitful in extracting information on selected-but at the same time most representative-complex systems like human brain, financial markets and natural language, from the time series representing the observables associated with these systems. The properties we focus on comprise the collective effects and their coexistence with noise, long-range interactions, the interplay between determinism and flexibility in evolution, scale invariance, criticality, multifractality and hierarchical structure. The methods described either originate from “hard” physics-like the random matrix theory-and then were transmitted to other fields of science via the field of complex systems research, or they originated elsewhere but turned out to be very useful also in physics - like, for example, fractal geometry. Further methods discussed borrow from the formalism of complex networks, from the theory of critical phenomena and from nonextensive statistical mechanics. Each of these methods is helpful in analyses of specific aspects of complexity and all of them are mutually complementary.
Proposal of Secure VoIP System Using Attribute Certificate
NASA Astrophysics Data System (ADS)
Kim, Jin-Mook; Jeong, Young-Ae; Hong, Seong-Sik
VoIP is a service that changes the analogue audio signal into a digital signal and then transfers the audio information to the users after configuring it as a packet; and it has an advantage of lower price than the existing voice call service and better extensibility. However, VoIP service has a system structure that, compared to the existing PSTN (Public Switched Telephone Network), has poor call quality and is vulnerable in the security aspect. To make up these problems, TLS service was introduced to enhance the security. In practical system, however, since QoS problem occurs, it is necessary to develop the VoIP security system that can satisfy QoS at the same time in the security aspect. In this paper, a user authentication VoIP system that can provide a service according to the security and the user through providing a differential service according to the approach of the users by adding AA server at the step of configuring the existing VoIP session is suggested. It was found that the proposed system of this study provides a quicker QoS than the TLS-added system at a similar level of security. Also, it is able to provide a variety of additional services by the different users.
NASA Astrophysics Data System (ADS)
Dong, Huan He; Guo, Bao Yong; Yin, Bao Shu
2016-06-01
In the paper, based on the modified Riemann-Liouville fractional derivative and Tu scheme, the fractional super NLS-MKdV hierarchy is derived, especially the self-consistent sources term is considered. Meanwhile, the generalized fractional supertrace identity is proposed, which is a beneficial supplement to the existing literature on integrable system. As an application, the super Hamiltonian structure of fractional super NLS-MKdV hierarchy is obtained.
Extreme winds and tornadoes: design and evaluation of buildings and structures
DOE Office of Scientific and Technical Information (OSTI.GOV)
McDonald, J.R.
1985-01-01
The general provisions of ANSI A58.1-1982 are explained in detail. As mentioned above, these procedures may be used to determine design wind loads on structures from extreme winds, hurricane and tornado winds. Treatment of atmospheric pressure change loads are discussed, including recommendations for venting a building, if necessary, and the effects of rate of pressure change on HVAC systems. Finally, techniques for evaluating existing facilities are described.
Machinery of protein folding and unfolding.
Zhang, Xiaodong; Beuron, Fabienne; Freemont, Paul S
2002-04-01
During the past two years, a large amount of biochemical, biophysical and low- to high-resolution structural data have provided mechanistic insights into the machinery of protein folding and unfolding. It has emerged that dual functionality in terms of folding and unfolding might exist for some systems. The majority of folding/unfolding machines adopt oligomeric ring structures in a cooperative fashion and utilise the conformational changes induced by ATP binding/hydrolysis for their specific functions.
Black hole shadows and invariant phase space structures
NASA Astrophysics Data System (ADS)
Grover, J.; Wittig, A.
2017-07-01
Utilizing concepts from dynamical systems theory, we demonstrate how the existence of light rings, or fixed points, in a spacetime will give rise to families of periodic orbits and invariant manifolds in phase space. It is shown that these structures can define the shape of the black hole shadow as well as a number of salient features of the spacetime lensing. We illustrate this through the analysis of lensing by a hairy black hole.
2008-05-02
information is estimated to average 1 hour per response, including g the time for reviewing instructions, searching existing data sources, gathering...their central engines cannot be resolved with ordinary telescopes. Gravitational telescopes, however, provide the necessary resolution to study the...structure of the continuum emission regions at optical and X-ray wavelengths and make time delay estimates in the systems in which sufficient data were
A nonlocal spatial model for Lyme disease
NASA Astrophysics Data System (ADS)
Yu, Xiao; Zhao, Xiao-Qiang
2016-07-01
This paper is devoted to the study of a nonlocal and time-delayed reaction-diffusion model for Lyme disease with a spatially heterogeneous structure. In the case of a bounded domain, we first prove the existence of the positive steady state and a threshold type result for the disease-free system, and then establish the global dynamics for the model system in terms of the basic reproduction number. In the case of an unbound domain, we obtain the existence of the disease spreading speed and its coincidence with the minimal wave speed. At last, we use numerical simulations to verify our analytic results and investigate the influence of model parameters and spatial heterogeneity on the disease infection risk.
“That model is sooooo last millennium!” Residential long term care as a system, not a place
Ziemba, Rosemary; Perry, Tam E.; Takahashi, Beverly; Algase, Donna
2010-01-01
The current quandary with the design of existing long term care (LTC) settings results from focus on structures (“institutions”) instead of on a system of supports and services that transcends physical and traditional boundaries across settings, including nursing homes, assisted living residences and the home. Supported by analysis of the commonalities, socio-historical and political contexts, core values and fallacies of social and medical models in existing and emerging LTC options, a holistic model is proposed based on new core values which facilitate community and family integration, and which asserts dignity and personhood as universal attributes in an array of settings. PMID:20640176
A Review of Artificial Lateral Line in Sensor Fabrication and Bionic Applications for Robot Fish.
Liu, Guijie; Wang, Anyi; Wang, Xinbao; Liu, Peng
2016-01-01
Lateral line is a system of sense organs that can aid fishes to maneuver in a dark environment. Artificial lateral line (ALL) imitates the structure of lateral line in fishes and provides invaluable means for underwater-sensing technology and robot fish control. This paper reviews ALL, including sensor fabrication and applications to robot fish. The biophysics of lateral line are first introduced to enhance the understanding of lateral line structure and function. The design and fabrication of an ALL sensor on the basis of various sensing principles are then presented. ALL systems are collections of sensors that include carrier and control circuit. Their structure and hydrodynamic detection are reviewed. Finally, further research trends and existing problems of ALL are discussed.
French Modular Impoundment: Final Cost and Performance Evaluation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Drown, Peter; French, Bill
This report comprises the Final Cost and Performance Report for the Department of Energy Award # EE0007244, the French Modular Impoundment (aka the “French Dam”.) The French Dam is a system of applying precast modular construction to water control structures. The “French Dam” is a term used to cover the construction means/methods used to construct or rehabilitate dams, diversion structures, powerhouses, and other hydraulic structures which impound water and are covered under FDE’s existing IP (Patents # US8414223B2; US9103084B2.)
Technology update: Tethered aerostat structural design and material developments
NASA Technical Reports Server (NTRS)
Witherow, R. G.
1975-01-01
Requirements exist for an extremely stable, high performance, all-weather tethered aerostat system. This requirement has been satisfied by a 250,000 cubic foot captive buoyant vehicle as demonstrated by over a year of successful field operations. This achievement required significant advancements in several technology areas including composite materials design, aerostatics and aerodynamics, structural design, electro-mechanical design, vehicle fabrication and mooring operations. This paper specifically addresses the materials and structural design aspects of pressurized buoyant vehicles as related to the general class of Lighter Than Air vehicles.
Structure identification methods for atomistic simulations of crystalline materials
Stukowski, Alexander
2012-05-28
Here, we discuss existing and new computational analysis techniques to classify local atomic arrangements in large-scale atomistic computer simulations of crystalline solids. This article includes a performance comparison of typical analysis algorithms such as common neighbor analysis (CNA), centrosymmetry analysis, bond angle analysis, bond order analysis and Voronoi analysis. In addition we propose a simple extension to the CNA method that makes it suitable for multi-phase systems. Finally, we introduce a new structure identification algorithm, the neighbor distance analysis, which is designed to identify atomic structure units in grain boundaries.
Underground pipeline laying using the pipe-in-pipe system
NASA Astrophysics Data System (ADS)
Antropova, N.; Krets, V.; Pavlov, M.
2016-09-01
The problems of resource saving and environmental safety during the installation and operation of the underwater crossings are always relevant. The paper describes the existing methods of trenchless pipeline technology, the structure of multi-channel pipelines, the types of supporting and guiding systems. The rational design is suggested for the pipe-in-pipe system. The finite element model is presented for the most dangerous sections of the inner pipes, the optimum distance is detected between the roller supports.
Equilibration and order in quantum Floquet matter
NASA Astrophysics Data System (ADS)
Moessner, R.; Sondhi, S. L.
2017-04-01
Equilibrium thermodynamics is characterized by two fundamental ideas: thermalization--that systems approach a late time thermal state; and phase structure--that thermal states exhibit singular changes as various parameters characterizing the system are changed. We summarize recent progress that has established generalizations of these ideas to periodically driven, or Floquet, closed quantum systems. This has resulted in the discovery of entirely new phases which exist only out of equilibrium, such as the π-spin glass/Floquet time crystal.
NASA Astrophysics Data System (ADS)
Wakil, K.; Hussnain, MQ; Tahir, A.; Naeem, M. A.
2016-06-01
Unmanaged placement, size, location, structure and contents of outdoor advertisement boards have resulted in severe urban visual pollution and deterioration of the socio-physical living environment in urban centres of Pakistan. As per the regulatory instruments, the approval decision for a new advertisement installation is supposed to be based on the locational density of existing boards and their proximity or remoteness to certain land- uses. In cities, where regulatory tools for the control of advertisement boards exist, responsible authorities are handicapped in effective implementation due to the absence of geospatial analysis capacity. This study presents the development of a spatial decision support system (SDSS) for regularization of advertisement boards in terms of their location and placement. The knowledge module of the proposed SDSS is based on provisions and restrictions prescribed in regulatory documents. While the user interface allows visualization and scenario evaluation to understand if the new board will affect existing linear density on a particular road and if it violates any buffer restrictions around a particular land use. Technically the structure of the proposed SDSS is a web-based solution which includes open geospatial tools such as OpenGeo Suite, GeoExt, PostgreSQL, and PHP. It uses three key data sets including road network, locations of existing billboards and building parcels with land use information to perform the analysis. Locational suitability has been calculated using pairwise comparison through analytical hierarchy process (AHP) and weighted linear combination (WLC). Our results indicate that open geospatial tools can be helpful in developing an SDSS which can assist solving space related iterative decision challenges on outdoor advertisements. Employing such a system will result in effective implementation of regulations resulting in visual harmony and aesthetic improvement in urban communities.
NASA Astrophysics Data System (ADS)
Jurčišinová, E.; Jurčišin, M.
2018-04-01
Anomalies of the specific heat capacity are investigated in the framework of the exactly solvable antiferromagnetic spin- 1 / 2 Ising model in the external magnetic field on the geometrically frustrated tetrahedron recursive lattice. It is shown that the Schottky-type anomaly in the behavior of the specific heat capacity is related to the existence of unique highly macroscopically degenerated single-point ground states which are formed on the borders between neighboring plateau-like ground states. It is also shown that the very existence of these single-point ground states with large residual entropies predicts the appearance of another anomaly in the behavior of the specific heat capacity for low temperatures, namely, the field-induced double-peak structure, which exists, and should be observed experimentally, along with the Schottky-type anomaly in various frustrated magnetic system.
Application of new electro-optic technology to Space Station Freedom data management system
NASA Technical Reports Server (NTRS)
Husbands, C. R.; Girard, M. M.
1993-01-01
A low risk design methodology to permit the local bus structures to support increased data carrying capacities and to speed messages and data flow between nodes or stations on the Space Station Freedom Data Management System in anticipation of growing requirements was evaluated and recommended. The recommended design employs a collateral fiber optic technique that follows a NATO avionic standard that is developed, tested, and available. Application of this process will permit a potential 25 fold increase in data transfer performance on the local wire bus network with a fiber optic network, maintaining the functionality of the low-speed bus and supporting all of the redundant transmission and fault detection capabilities designed into the existing system. The application of wavelength division multiplexing (WDM) technology to both the local data bus and global data bus segments of the Data Management System to support anticipated additional highspeed data transmission requirements was also examined. Techniques were examined to provide a dual wavelength implementation of the fiber optic collateral networks. This dual wavelength implementation would permit each local bus to support two simultaneous high-speed transfers on the same fiber optic bus structure and operate within the limits of the existing protocol standard. A second WDM study examined the use of spectral sliced technology to provide a fourfold increase in the Fiber Distributed Data Interface (FDDI) global bus networks without requiring modifications to the existing installed cable plant. Computer simulations presented indicated that this data rate improvement can be achieved with commercially available optical components.
Up gradation of LHCD system for rf power level up to 2MW for SST1
NASA Astrophysics Data System (ADS)
Sharma, P. K.; Ambulkar, K. K.; Parmar, P. R.; Virani, C. G.; Thakur, A. L.; Kulkarni, S. V.; Lhcd Group
2010-02-01
To operate superconducting steadystate tokamak (SST1) for 1000 seconds, lower hybrid current drive (LHCD) system has been designed at a frequency of 3.7 GHz., which would couple 1.0 MW CW of microwave power to the shaped plasma. The system consists of various rf passive components and transmission line, employing which the rf power from the source is transported to the antenna. During calibration of transmission line, it was observed that the losses in the transmission line is substantial and eventually would lead to less coupled power to the plasma. Further it is anticipated that more LH power would be required for advanced operation of SST1 machine. Thus it is decided to upgrade the existing LHCD system to 2 MW CW power level. The proposed up gradation would demand several infra structural changes and needs to be addressed. Due to lack of space, we have proposed a scheme in which additional two klystrons, along with existing two klystrons would be accommodated in the existing space. The low rf power requirements have also been increased to cater the new needs. Accordingly additional cooling requirements have been proposed to accommodate the two new klystrons. The DAC and auxiliary power supplies have been also designed. The new up graded LHCD system would address several key technological issues. Firstly it would establish the operation of four klystrons at rated power in parallel employing single RHVPS (80kV, 70A). Secondly it would establish the operation of two high power klystrons operation at rated power when their collectors are cooled in series. In this paper we would present the various requirements for up-gradation of LHCD system to 2MW. The main requirements like high power rf source, along with modified support structure, low power rf systems to drive the high power rf source, auxiliary power supplies required for high power rf source, DAC system improvement, cooling improvements, etc. would be discussed.
NASA Astrophysics Data System (ADS)
Guardo, Roberto; De Siena, Luca
2017-04-01
The timely estimation of short- and long-term volcanic hazard relies on the existence of detailed 3D geophysical images of volcanic structures. High-resolution seismic models of the absorbing uppermost conduit systems and highly-heterogeneous shallowest volcanic layers, while particularly challenging to obtain, provide important data to locate feasible eruptive centers and forecast flank collapses and lava ascending paths. Here, we model the volcanic structures of Mt. Etna (Sicily, Italy) and its outskirts using the Horizontal to Vertical Spectral Ratio method, generally applied to industrial and engineering settings. The integration of this technique with Web-based Geographic Information System improves precision during the acquisition phase. It also integrates geological and geophysical visualization of 3D surface and subsurface structures in a queryable environment representing their exact three-dimensional geographic position, enhancing interpretation. The results show high-resolution 3D images of the shallowest volcanic and feeding systems, which complement (1) deeper seismic tomography imaging and (2) the results of recent remote sensing imaging. The main novelty with respect to previous model is the presence of a vertical structure that divides the pre-existing volcanic complexes of Ellittico and Cuvigghiuni. This could be interpreted as a transitional phase between the two systems. A comparison with recent remote sensing and geological results, however, shows clear connections between the anomaly and dynamic active during the last 15 years. We infer that seismic noise measurements from miniaturized instruments, when combined with remote sensing techniques, represent an important resource when monitoring volcanic media and eruptions, reducing the risk of loss of human lives and instrumentation.
Nursing Classification Systems
Henry, Suzanne Bakken; Mead, Charles N.
1997-01-01
Abstract Our premise is that from the perspective of maximum flexibility of data usage by computer-based record (CPR) systems, existing nursing classification systems are necessary, but not sufficient, for representing important aspects of “what nurses do.” In particular, we have focused our attention on those classification systems that represent nurses' clinical activities through the abstraction of activities into categories of nursing interventions. In this theoretical paper, we argue that taxonomic, combinatorial vocabularies capable of coding atomic-level nursing activities are required to effectively capture in a reproducible and reversible manner the clinical decisions and actions of nurses, and that, without such vocabularies and associated grammars, potentially important clinical process data is lost during the encoding process. Existing nursing intervention classification systems do not fulfill these criteria. As background to our argument, we first present an overview of the content, methods, and evaluation criteria used in previous studies whose focus has been to evaluate the effectiveness of existing coding and classification systems. Next, using the Ingenerf typology of taxonomic vocabularies, we categorize the formal type and structure of three existing nursing intervention classification systems—Nursing Interventions Classification, Omaha System, and Home Health Care Classification. Third, we use records from home care patients to show examples of lossy data transformation, the loss of potentially significant atomic data, resulting from encoding using each of the three systems. Last, we provide an example of the application of a formal representation methodology (conceptual graphs) which we believe could be used as a model to build the required combinatorial, taxonomic vocabulary for representing nursing interventions. PMID:9147341
NASA Astrophysics Data System (ADS)
Riesmeier, Joerg; Eichelberg, Marco; Kleber, Klaus; Groenemeyer, Dietrich H.; Oosterwijk, Herman J.; Jensch, Peter F.
2002-05-01
With the release of 'DICOM Structured Reporting' (SR) as an official extension of the standard about two years ago, DICOM has entered a new domain that is only indirectly related to medical imaging. Basically, DICOM SR is a general model allowing to encode medical reports in a structured manner in DICOM's tag-based format. Therefore, the existing DICOM infrastructure can be used to archive and communicate structured reports, with only relatively small changes to existing systems. As a consequence of the introduction of medical reports in a digital form, the relevance of security measures increases significantly. We have developed a prototype implementation of DICOM structured reporting together with the new security extensions for secure transport connections and digital signatures. The application allows to create, read and modify any SR document, to digitally sign an SR document in whole or part and to transmit such documents over a network. While the secure transport connection protects data from modifications or unauthorized access only during transmission, digital signatures provide a lifetime integrity check and, therefore, maintain the legal document status of structured reports. The application has been successfully demonstrated at RSNA 2000 and ECR 2001, and is freely available on the Internet.
A global analysis approach for investigating structural resilience in urban drainage systems.
Mugume, Seith N; Gomez, Diego E; Fu, Guangtao; Farmani, Raziyeh; Butler, David
2015-09-15
Building resilience in urban drainage systems requires consideration of a wide range of threats that contribute to urban flooding. Existing hydraulic reliability based approaches have focused on quantifying functional failure caused by extreme rainfall or increase in dry weather flows that lead to hydraulic overloading of the system. Such approaches however, do not fully explore the full system failure scenario space due to exclusion of crucial threats such as equipment malfunction, pipe collapse and blockage that can also lead to urban flooding. In this research, a new analytical approach based on global resilience analysis is investigated and applied to systematically evaluate the performance of an urban drainage system when subjected to a wide range of structural failure scenarios resulting from random cumulative link failure. Link failure envelopes, which represent the resulting loss of system functionality (impacts) are determined by computing the upper and lower limits of the simulation results for total flood volume (failure magnitude) and average flood duration (failure duration) at each link failure level. A new resilience index that combines the failure magnitude and duration into a single metric is applied to quantify system residual functionality at each considered link failure level. With this approach, resilience has been tested and characterised for an existing urban drainage system in Kampala city, Uganda. In addition, the effectiveness of potential adaptation strategies in enhancing its resilience to cumulative link failure has been tested. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
Strengthening health systems by health sector reforms
Senkubuge, Flavia; Modisenyane, Moeketsi; Bishaw, Tewabech
2014-01-01
Background The rising burden of disease and weak health systems are being compounded by the persistent economic downturn, re-emerging diseases, and violent conflicts. There is a growing recognition that the global health agenda needs to shift from an emphasis on disease-specific approaches to strengthening of health systems, including dealing with social, environmental, and economic determinants through multisectoral responses. Methods A review and analysis of data on strengthening health sector reform and health systems was conducted. Attention was paid to the goal of health and interactions between health sector reforms and the functions of health systems. Further, we explored how these interactions contribute toward delivery of health services, equity, financial protection, and improved health. Findings Health sector reforms cannot be developed from a single global or regional policy formula. Any reform will depend on the country's history, values and culture, and the population's expectations. Some of the emerging ingredients that need to be explored are infusion of a health systems agenda; development of a comprehensive policy package for health sector reforms; improving alignment of planning and coordination; use of reliable data; engaging ‘street level’ policy implementers; strengthening governance and leadership; and allowing a holistic and developmental approach to reforms. Conclusions The process of reform needs a fundamental rather than merely an incremental and evolutionary change. Without radical structural and systemic changes, existing governance structures and management systems will continue to fail to address the existing health problems. PMID:24560261
7 CFR 1794.21 - Categorically excluded proposals without an ER.
Code of Federal Regulations, 2010 CFR
2010-01-01
... an emergency situation to return to service damaged facilities of an applicant's system. (b) Electric... electric generating or fuel processing facilities and related support structures where there is negligible... boundaries of an existing electric generating facility site. A description of the facilities to be...
USDA-ARS?s Scientific Manuscript database
Zinc was recognized as an essential trace metal for humans during the studies of Iranian adolescent dwarfs in the early 1960s. Zinc metal existing as Zn2+ is a strong electron acceptor in biological systems without risks of oxidant damage to cells. Zn2+ functions in the structure of proteins and is ...
Command and Control for Distributed Lethality
2017-06-01
based systems engineering (MBSE) approach to C2 within the distributed lethality environment requires development of methodologies to provide...lethality environment requires development of methodologies to provide definition and structure for existing operational concepts while providing...2 D. SCOPE AND METHODOLOGY ............................................................2 E. STAKEHOLDER ANALYSIS
A Structural and Content-Based Analysis for Web Filtering.
ERIC Educational Resources Information Center
Lee, P. Y.; Hui, S. C.; Fong, A. C. M.
2003-01-01
Presents an analysis of the distinguishing features of pornographic Web pages so that effective filtering techniques can be developed. Surveys the existing techniques for Web content filtering and describes the implementation of a Web content filtering system that uses an artificial neural network. (Author/LRW)
The Basic Paradigm of a Future Socio-Cultural System.
ERIC Educational Resources Information Center
Hine, Virginia H.
1978-01-01
The paradigm of a future global society may already exist in a nonbureaucratic organization structure called a Segmented Polycephalous Network (SPN). A SPN consists of autonomous segments with horizontal linkages, multiple leaders, and a common ideology. Grass roots movements and multinational corporations are examples. (SJL)
Nonlinear Ultrasonic Diagnosis and Prognosis of ASR Damage in Dry Cask Storage
DOE Office of Scientific and Technical Information (OSTI.GOV)
Qu, Jianmin; Bazant, Zdenek; Jacobs, Laurence
Alkali-silica reaction (ASR) is a deleterious chemical process that may occur in cement-based materials such as mortars and concretes, where the hydroxyl ions in the highly alkaline pore solution attack the siloxane groups in the siliceous minerals in the aggregates. The reaction produces a cross-linked alkali-silica gel. The ASR gel swells in the presence of water. Expansion of the gel results in cracking when the swelling-induced stress exceeds the fracture toughness of the concrete. As the ASR continues, cracks may grow and eventually coalesce, which results in reduced service life and a decrease safety of concrete structures. Since concrete ismore » widely used as a critical structural component in dry cask storage of used nuclear fuels, ASR damage poses a significant threat to the sustainability of long term dry cask storage systems. Therefore, techniques for effectively detecting, managing and mitigating ASR damage are needed. Currently, there are no nondestructive methods to accurately detect ASR damage in existing concrete structures. The only current way of accurately assessing ASR damage is to drill a core from an existing structure, and conduct microscopy on this drilled cylindrical core. Clearly, such a practice is not applicable to dry cask storage systems. To meet these needs, this research is aimed at developing (1) a suite of nonlinear ultrasonic quantitative nondestructive evaluation (QNDE) techniques to characterize ASR damage, and (2) a physics-based model for ASR damage evolution using the QNDE data. Outcomes of this research will provide a nondestructive diagnostic tool to evaluate the extent of the ASR damage, and a prognostic tool to estimate the future reliability and safety of the concrete structures in dry cask storage systems« less
Incentives in financing mental health care in Austria.
Zechmeister, Ingrid; Oesterle, August; Denk, Peter; Katschnig, Heinz
2002-09-01
In Austria, financing health care -and even more so mental health care- is characterized by a mix of federal and provincial responsibilities, lack of uniformity in service provision and service providers, and diverse funding arrangements. The division between financing structures for health care and social care makes the situation even more complex. This state of affairs results in various, partly counterproductive and sometimes paradoxical financial incentives and disincentives for the providers, recipients and financiers of mental health services. In several provinces of Austria, recent reform plans in mental health care have focused strongly on establishing community-based and patient-oriented mental health care. One of the main challenges in implementing this new policy is the re-allocation of resources. The authors hypothesize that the existing structure of mental health care financing, with its incentives and disincentives, constitutes an obstacle to patient-oriented community-based mental health care. Analyzing the characteristics of the overall mental health care financing system in one Austrian province, Lower Austria, will provide a better understanding of actor-relationships and inherent incentives and highlight implications for the process of deinstitutionalization. The authors used an analytical framework based on the principal-agent theory, empirical evidence, and information on financial, organizational and legal structures to identify the characteristics of actor-relationships and the position of single actors within the system. The article shows how incentives are linked to existing constellations of actors involved in mental health care financing and identifies significant power relations. As a consequence, incentives and disincentives within the financing system result in hospital- centered and supply-oriented mental health care in Lower Austria. The current system of financing mental health care provides an obstacle to the provision of patient-oriented and community-based mental care. This is due to existing constellations and power relations among the actors where, most importantly, patients are the weakest party in the patient-payer-provider triangle. Balancing power relations will be a significant prerequisite for alternative financing systems. IMPLICATIONS FOR HEALTH POLICIES AND FURTHER RESEARCH: If a community and needs-based mental health care system is to be established in Austria, the financing structures have to be changed accordingly. Applying a principal-agent framework is useful for identifying key aspects in mental health care financing in relation to the provision of services. Further research is needed to help develop alternative financing mechanisms that support community-based and patient-oriented mental health care systems.
Nonlinear Dynamics of Complex Coevolutionary Systems in Historical Times
NASA Astrophysics Data System (ADS)
Perdigão, Rui A. P.
2016-04-01
A new theoretical paradigm for statistical-dynamical modeling of complex coevolutionary systems is introduced, with the aim to provide historical geoscientists with a practical tool to analyse historical data and its underlying phenomenology. Historical data is assumed to represent the history of dynamical processes of physical and socio-economic nature. If processes and their governing laws are well understood, they are often treated with traditional dynamical equations: deterministic approach. If the governing laws are unknown or impracticable, the process is often treated as if being random (even if it is not): statistical approach. Although single eventful details - such as the exact spatiotemporal structure of a particular hydro-meteorological incident - may often be elusive to a detailed analysis, the overall dynamics exhibit group properties summarized by a simple set of categories or dynamical regimes at multiple scales - from local short-lived convection patterns to large-scale hydro-climatic regimes. The overwhelming microscale complexity is thus conveniently wrapped into a manageable group entity, such as a statistical distribution. In a stationary setting whereby the distribution is assumed to be invariant, alternating regimes are approachable as dynamical intermittence. For instance, in the context of bimodal climatic oscillations such as NAO and ENSO, each mode corresponds to a dynamical regime or phase. However, given external forcings or longer-term internal variability and multiscale coevolution, the structural properties of the system may change. These changes in the dynamical structure bring about a new distribution and associated regimes. The modes of yesteryear may no longer exist as such in the new structural order of the system. In this context, aside from regime intermittence, the system exhibits structural regime change. New oscillations may emerge whilst others fade into the annals of history, e.g. particular climate fluctuations during the Little Ice Age. Traditional theories of stochastic processes and dynamical systems are grounded on the existence of so-called dynamical invariants; properties that remain unchanged as the dynamics unfold, assuming structural invariance and ergodicity of the underlying system. However, such theories are no longer optimal when trying to understand and model long-term historical records of coevolutionary systems. A new paradigm is thus needed. Therefore, we introduce a new class of dynamical systems that reinvent themselves as the dynamics unfold. Rather than only changing variables and parameters under a rigid framework, the governing laws are malleable themselves. The novel formulation captures and explains the coevolutionary dynamics of multiscale hydroclimatic systems, bringing along a physically sound understanding of their regimes, transitions and extremes over a long-term history.
An Experimental Study on Strengthening of Reinforced Concrete Flexural Members using Steel Wire Mesh
NASA Astrophysics Data System (ADS)
Al Saadi, Hamza Salim Mohammed; Mohandas, Hoby P.; Namasivayam, Aravind
2017-01-01
One of the major challenges and contemporary research in the field of structural engineering is strengthening of existing structural elements using readily available materials in the market. Several investigations were conducted on strengthening of various structural components using traditional and advanced materials. Many researchers tried to enhance the reinforced concrete (RC) beams strength using steel plate, Glass and Carbon Fibre Reinforced Polymers (GFRP & CFRP). For the reason that high weight to the strength ratio and compatibility in strength between FRP composites and steel bars, steel plates and GFRP and CFRP composites are not used for strengthening works practically. Hence, in this present work the suitability of using wire mesh for the purpose of strengthening the RC flexural members is studied by conducting experimental works. New technique of strengthening system using wire mesh with a view to improve sectional properties and subsequently flexural strength of RC beams is adopted in this work. The results for experimental and theoretical analysis were compared and found that good correlation exists between them. The experimental results indicate that RC beams strengthened with steel wire mesh are easy technique for strengthening of existing flexural members.
Opto-mechanical design of small infrared cloud measuring device
NASA Astrophysics Data System (ADS)
Zhang, Jiao; Yu, Xun; Tao, Yu; Jiang, Xu
2018-01-01
In order to make small infrared cloud measuring device can be well in a wide temperature range and day-night environment, a design idea using catadioptric infrared panoramic imaging optical system and simple mechanical structure for realizing observation clode under all-weather conditions was proposed. Firstly, the optical system of cloud measuring device was designed. An easy-to-use numerical method was proposed to acquire the profile of a catadioptric mirror, which brought the property of equidistance projection and played the most important role in a catadioptric panoramic lens. Secondly, the mechanical structure was studied in detail. Overcoming the limitations of traditional primary mirror support structure, integrative design was used for refractor and mirror support structure. Lastly, temperature adaptability and modes of the mirror support structure were analyzed. Results show that the observation range of the cloud measuring device is wide and the structure is simple, the fundamental frequency of the structure is greater than 100 Hz, the surface precision of the system reflector reaches PV of λ/10 and RMS of λ/40under the load of temperature range - 40 60°C, it can meet the needs of existing meteorological observation.
Basins of distinct asymptotic states in the cyclically competing mobile five species game
NASA Astrophysics Data System (ADS)
Kim, Beomseok; Park, Junpyo
2017-10-01
We study the dynamics of cyclic competing mobile five species on spatially extended systems originated from asymmetric initial populations and investigate the basins for the three possible asymptotic states, coexistence of all species, existences of only two independent species, and the extinction. Through extensive numerical simulations, we find a prosperous dependence on initial conditions for species biodiversity. In particular, for fixed given equal densities of two relevant species, we find that only five basins for the existence of two independent species exist and they are spirally entangled for high mobility. A basin of coexistence is outbreaking when the mobility parameter is decreased through a critical value and surrounded by the other five basins. For fixed given equal densities of two independent species, however, we find that basin structures are not spirally entangled. Further, final states of two independent species are totally different. For all possible considerations, the extinction state is not witnessed which is verified by the survival probability. To provide the validity of basin structures from lattice simulations, we analyze the system in mean-field manners. Consequently, results on macroscopic levels are matched to direct lattice simulations for high mobility regimes. These findings provide a good insight into the fundamental issue of the biodiversity among many species than previous cases.
Correlations in the degeneracy of structurally controllable topologies for networks
NASA Astrophysics Data System (ADS)
Campbell, Colin; Aucott, Steven; Ruths, Justin; Ruths, Derek; Shea, Katriona; Albert, Réka
2017-04-01
Many dynamic systems display complex emergent phenomena. By directly controlling a subset of system components (nodes) via external intervention it is possible to indirectly control every other component in the system. When the system is linear or can be approximated sufficiently well by a linear model, methods exist to identify the number and connectivity of a minimum set of external inputs (constituting a so-called minimal control topology, or MCT). In general, many MCTs exist for a given network; here we characterize a broad ensemble of empirical networks in terms of the fraction of nodes and edges that are always, sometimes, or never a part of an MCT. We study the relationships between the measures, and apply the methodology to the T-LGL leukemia signaling network as a case study. We show that the properties introduced in this report can be used to predict key components of biological networks, with potentially broad applications to network medicine.
NASA Technical Reports Server (NTRS)
Ciciora, J. A.; Leonard, S. D.; Johnson, N.; Amell, J.
1984-01-01
In order to derive general design guidelines for automated systems a study was conducted on the utilization and acceptance of existing automated systems as currently employed in several commercial fields. Four principal study area were investigated by means of structured interviews, and in some cases questionnaires. The study areas were aviation, a both scheduled airline and general commercial aviation; process control and factory applications; office automation; and automation in the power industry. The results of over eighty structured interviews were analyzed and responses categoried as various human factors issues for use by both designers and users of automated equipment. These guidelines address such items as general physical features of automated equipment; personnel orientation, acceptance, and training; and both personnel and system reliability.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Borhanian, J.; Shahmansouri, M.
2013-01-15
A theoretical investigation is carried out to study the existence and characteristics of propagation of dust-acoustic (DA) waves in an electron-depleted dusty plasma with two-temperature ions, which are modeled by kappa distribution functions. A three-dimensional cylindrical Kadomtsev-Petviashvili equation governing evolution of small but finite amplitude DA waves is derived by means of a reductive perturbation method. The influence of physical parameters on solitary wave structure is examined. Furthermore, the energy integral equation is used to study the existence domains of the localized structures. It is found that the present model can be employed to describe the existence of positive asmore » well as negative polarity DA solitary waves by selecting special values for parameters of the system, e.g., superthermal index of cold and/or hot ions, cold to hot ion density ratio, and hot to cold ion temperature ratio. This model may be useful to understand the excitation of nonlinear DA waves in astrophysical objects.« less
NASA Astrophysics Data System (ADS)
Dunlap, Lucas
2016-11-01
I argue that Deutsch's model for the behavior of systems traveling around closed timelike curves (CTCs) relies implicitly on a substantive metaphysical assumption. Deutsch is employing a version of quantum theory with a significantly supplemented ontology of parallel existent worlds, which differ in kind from the many worlds of the Everett interpretation. Standard Everett does not support the existence of multiple identical copies of the world, which the D-CTC model requires. This has been obscured because he often refers to the branching structure of Everett as a "multiverse", and describes quantum interference by reference to parallel interacting definite worlds. But he admits that this is only an approximation to Everett. The D-CTC model, however, relies crucially on the existence of a multiverse of parallel interacting worlds. Since his model is supplemented by structures that go significantly beyond quantum theory, and play an ineliminable role in its predictions and explanations, it does not represent a quantum solution to the paradoxes of time travel.
NASA Astrophysics Data System (ADS)
Hermens, Ulrike; Pothen, Mario; Winands, Kai; Arntz, Kristian; Klocke, Fritz
2018-02-01
Laser-induced periodic surface structures (LIPSS) found in particular applications in the fields of surface functionalization have been investigated since many years. The direction of these ripple structures with a periodicity in the nanoscale can be manipulated by changing the laser polarization. For industrial use, it is useful to manipulate the direction of these structures automatically and to obtain smooth changes of their orientation without any visible inhomogeneity. However, currently no system solution exists that is able to control the polarization direction completely automated in one software solution so far. In this paper, a system solution is presented that includes a liquid crystal polarizer to control the polarization direction. It is synchronized with a scanner, a dynamic beam expander and a five axis-system. It provides fast switching times and small step sizes. First results of fabricated structures are also presented. In a systematic study, the conjunction of LIPSS with different orientation in two parallel line scans has been investigated.
ER2OWL: Generating OWL Ontology from ER Diagram
NASA Astrophysics Data System (ADS)
Fahad, Muhammad
Ontology is the fundamental part of Semantic Web. The goal of W3C is to bring the web into (its full potential) a semantic web with reusing previous systems and artifacts. Most legacy systems have been documented in structural analysis and structured design (SASD), especially in simple or Extended ER Diagram (ERD). Such systems need up-gradation to become the part of semantic web. In this paper, we present ERD to OWL-DL ontology transformation rules at concrete level. These rules facilitate an easy and understandable transformation from ERD to OWL. The set of rules for transformation is tested on a structured analysis and design example. The framework provides OWL ontology for semantic web fundamental. This framework helps software engineers in upgrading the structured analysis and design artifact ERD, to components of semantic web. Moreover our transformation tool, ER2OWL, reduces the cost and time for building OWL ontologies with the reuse of existing entity relationship models.
A robust adaptive observer for a class of singular nonlinear uncertain systems
NASA Astrophysics Data System (ADS)
Arefinia, Elaheh; Talebi, Heidar Ali; Doustmohammadi, Ali
2017-05-01
This paper proposes a robust adaptive observer for a class of singular nonlinear non-autonomous uncertain systems with unstructured unknown system and derivative matrices, and unknown bounded nonlinearities. Unlike many existing observers, no strong assumption such as Lipschitz condition is imposed on the recommended system. An augmented system is constructed, and the unknown bounds are calculated online using adaptive bounding technique. Considering the continuous nonlinear gain removes the chattering which may appear in practical applications such as analysis of electrical circuits and estimation of interaction force in beating heart robotic-assisted surgery. Moreover, a simple yet precise structure is attained which is easy to implement in many systems with significant uncertainties. The existence conditions of the standard form observer are obtained in terms of linear matrix inequality and the constrained generalised Sylvester's equations, and global stability is ensured. Finally, simulation results are obtained to evaluate the performance of the proposed estimator and demonstrate the effectiveness of the developed scheme.
A Survey on Anomaly Based Host Intrusion Detection System
NASA Astrophysics Data System (ADS)
Jose, Shijoe; Malathi, D.; Reddy, Bharath; Jayaseeli, Dorathi
2018-04-01
An intrusion detection system (IDS) is hardware, software or a combination of two, for monitoring network or system activities to detect malicious signs. In computer security, designing a robust intrusion detection system is one of the most fundamental and important problems. The primary function of system is detecting intrusion and gives alerts when user tries to intrusion on timely manner. In these techniques when IDS find out intrusion it will send alert massage to the system administrator. Anomaly detection is an important problem that has been researched within diverse research areas and application domains. This survey tries to provide a structured and comprehensive overview of the research on anomaly detection. From the existing anomaly detection techniques, each technique has relative strengths and weaknesses. The current state of the experiment practice in the field of anomaly-based intrusion detection is reviewed and survey recent studies in this. This survey provides a study of existing anomaly detection techniques, and how the techniques used in one area can be applied in another application domain.
Structural and practical identifiability analysis of S-system.
Zhan, Choujun; Li, Benjamin Yee Shing; Yeung, Lam Fat
2015-12-01
In the field of systems biology, biological reaction networks are usually modelled by ordinary differential equations. A sub-class, the S-systems representation, is a widely used form of modelling. Existing S-systems identification techniques assume that the system itself is always structurally identifiable. However, due to practical limitations, biological reaction networks are often only partially measured. In addition, the captured data only covers a limited trajectory, therefore data can only be considered as a local snapshot of the system responses with respect to the complete set of state trajectories over the entire state space. Hence the estimated model can only reflect partial system dynamics and may not be unique. To improve the identification quality, the structural and practical identifiablility of S-system are studied. The S-system is shown to be identifiable under a set of assumptions. Then, an application on yeast fermentation pathway was conducted. Two case studies were chosen; where the first case is based on a larger state trajectories and the second case is based on a smaller one. By expanding the dataset which span a relatively larger state space, the uncertainty of the estimated system can be reduced. The results indicated that initial concentration is related to the practical identifiablity.
NASA Astrophysics Data System (ADS)
Farías, Cristian; Galván, Boris; Miller, Stephen A.
2017-09-01
Earthquake triggering of hydrothermal and volcanic systems is ubiquitous, but the underlying processes driving these systems are not well-understood. We numerically investigate the influence of seismic wave interaction with volcanic systems simulated as a trapped, high-pressure fluid reservoir connected to a fluid-filled fault system in a 2-D poroelastic medium. Different orientations and earthquake magnitudes are studied to quantify dynamic and static stress, and pore pressure changes induced by a seismic event. Results show that although the response of the system is mainly dominated by characteristics of the radiated seismic waves, local structures can also play an important role on the system dynamics. The fluid reservoir affects the seismic wave front, distorts the static overpressure pattern induced by the earthquake, and concentrates the kinetic energy of the incoming wave on its boundaries. The static volumetric stress pattern inside the fault system is also affected by the local structures. Our results show that local faults play an important role in earthquake-volcanic systems dynamics by concentrating kinetic energy inside and acting as wave-guides that have a breakwater-like behavior. This generates sudden changes in pore pressure, volumetric expansion, and stress gradients. Local structures also influence the regional Coulomb yield function. Our results show that local structures affect the dynamics of volcanic and hydrothermal systems, and should be taken into account when investigating triggering of these systems from nearby or distant earthquakes.
NASA Astrophysics Data System (ADS)
Coussement, C.; Gente, P.; Rolet, J.; Tiercelin, J.-J.; Wafula, M.; Buku, S.
1994-10-01
The two branches of the East African Rift system include numerous hydrothermal fields, which are closely related to the present fault motion and to volcanic and seismic activity. In this study structural data from Pemba and Cape Banza hydrothermal fields (western branch, North Tanganyika, Zaire) are discussed in terms of neotectonic phenomena. Different types of records, such as fieldwork (onshore and underwater) and LANDSAT and SPOT imagery, are used to explain structural controls on active and fossil hydrothermal systems and their significance. The Pemba site is located at the intersection of 000-020°-trending normal faults belonging to the Uvira Border Fault System and a 120-130°-trending transtensional fault zone and is an area of high seismicity, with events of relatively large magnitude ( Ms < 6.5). The Cape Banza site occurs at the northern end of the Ubawari Peninsula horst. It is bounded by two fault systems trending 015° and is characterized seismically by events of small magnitude ( Ms < 4). The hydrothermal area itself is tectonically controlled by structures striking 170-180° and 080°. The analysis of both hydrothermal areas demonstrates the rejuvenation of older Proterozoic structures during Recent rift faulting and the location of the hydrothermal activity at the junctions of submeridian and transverse faults. The fault motion is compatible with a regional direction of extension of 090-110°. The Cape Banza and Pemba hydrothermal fields may testify to magma chambers existing below the junctions of the faults. They appear to form at structural nodes and may represent a future volcanic province. Together with the four surface volcanic provinces existing along the western branch, they possibly indicate an incipient rift segmentation related to 'valley-valley' or 'transverse fault-valley' junctions, contrasting with the spacing of the volcanoes measured in the eastern branch. These spacings appear to express the different elastic thicknesses between the eastern and western branches of the East African Rift system, perhaps related to a difference in stage of evolution of the two branches.
NASA Astrophysics Data System (ADS)
Izham, Mohamad Yusoff; Muhamad Uznir, Ujang; Alias, Abdul Rahman; Ayob, Katimon; Wan Ruslan, Ismail
2011-04-01
Existing 2D data structures are often insufficient for analysing the dynamism of saturation excess overland flow (SEOF) within a basin. Moreover, all stream networks and soil surface structures in GIS must be preserved within appropriate projection plane fitting techniques known as georeferencing. Inclusion of 3D volumetric structure of the current soft geo-objects simulation model would offer a substantial effort towards representing 3D soft geo-objects of SEOF dynamically within a basin by visualising saturated flow and overland flow volume. This research attempts to visualise the influence of a georeference system towards the dynamism of overland flow coverage and total overland flow volume generated from the SEOF process using VSG data structure. The data structure is driven by Green-Ampt methods and the Topographic Wetness Index (TWI). VSGs are analysed by focusing on spatial object preservation techniques of the conformal-based Malaysian Rectified Skew Orthomorphic (MRSO) and the equidistant-based Cassini-Soldner projection plane under the existing geodetic Malaysian Revised Triangulation 1948 (MRT48) and the newly implemented Geocentric Datum for Malaysia (GDM2000) datum. The simulated result visualises deformation of SEOF coverage under different georeference systems via its projection planes, which delineate dissimilar computation of SEOF areas and overland flow volumes. The integration of Georeference, 3D GIS and the saturation excess mechanism provides unifying evidence towards successful landslide and flood disaster management through envisioning the streamflow generating process (mainly SEOF) in a 3D environment.
Statistical Properties of Lorenz-like Flows, Recent Developments and Perspectives
NASA Astrophysics Data System (ADS)
Araujo, Vitor; Galatolo, Stefano; Pacifico, Maria José
We comment on the mathematical results about the statistical behavior of Lorenz equations and its attractor, and more generally on the class of singular hyperbolic systems. The mathematical theory of such kind of systems turned out to be surprisingly difficult. It is remarkable that a rigorous proof of the existence of the Lorenz attractor was presented only around the year 2000 with a computer-assisted proof together with an extension of the hyperbolic theory developed to encompass attractors robustly containing equilibria. We present some of the main results on the statistical behavior of such systems. We show that for attractors of three-dimensional flows, robust chaotic behavior is equivalent to the existence of certain hyperbolic structures, known as singular-hyperbolicity. These structures, in turn, are associated with the existence of physical measures: in low dimensions, robust chaotic behavior for flows ensures the existence of a physical measure. We then give more details on recent results on the dynamics of singular-hyperbolic (Lorenz-like) attractors: (1) there exists an invariant foliation whose leaves are forward contracted by the flow (and further properties which are useful to understand the statistical properties of the dynamics); (2) there exists a positive Lyapunov exponent at every orbit; (3) there is a unique physical measure whose support is the whole attractor and which is the equilibrium state with respect to the center-unstable Jacobian; (4) this measure is exact dimensional; (5) the induced measure on a suitable family of cross-sections has exponential decay of correlations for Lipschitz observables with respect to a suitable Poincaré return time map; (6) the hitting time associated to Lorenz-like attractors satisfy a logarithm law; (7) the geometric Lorenz flow satisfies the Almost Sure Invariance Principle (ASIP) and the Central Limit Theorem (CLT); (8) the rate of decay of large deviations for the volume measure on the ergodic basin of a geometric Lorenz attractor is exponential; (9) a class of geometric Lorenz flows exhibits robust exponential decay of correlations; (10) all geometric Lorenz flows are rapidly mixing and their time-1 map satisfies both ASIP and CLT.
Natural Materials, Systems & Extremophiles
2012-03-06
system. Linked: FY11 AFRL/RX pgm • Structural Coloration – new area, several PIs moving in and out; MURI (Harvard) • Biopolymers – Mainly silk but...looking at other biopolymers . The silk work is well integrated with AFRL; many exchanges of personnel & material. Some PIs moving out with...it pertains to marking items. • Silk – DARPA has contributed to my existing program. ARO has a single grantee. ONR funds a single investigator. NSF
Statistical Control Paradigm for Aerospace Structures Under Impulsive Disturbances
2006-08-03
attitude control system with an innovative and robust statistical controller design shows significant promise for use in attitude hold mode operation...indicate that the existing attitude control system with an innovative and robust statistical controller design shows significant promise for use in...and three thrusters are for use in controlling the attitude of the satellite. Then the angular momentum of the satellite with three thrusters and a
2017-10-03
and Microbiome Research Seminar Series . Baylor College of Medicine. 10/26/16. 12. "Rewiring the DNA binding domains ofbacterial two-component system...Structural and Quantitative Biology Seminar Series . 11/16/15. 16. "Engineering bacterial two component signal transduction systems to function as sensors...hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and
ERIC Educational Resources Information Center
Nachrichten fur Dokumentation, 1982
1982-01-01
In order to further develop West German information services for education, it is suggested that the ERIC structural model--a coordinating central office and a network of clearinghouses--be developed as a continuation of the existing "Dokumentationsring Padagogik" (DOPAED) documentation service. (16 references) (EJS)
An assessment of patient sign-outs conducted by University at Buffalo internal medicine residents.
Wheat, Deirdre; Co, Christopher; Manochakian, Rami; Rich, Ellen
2012-01-01
Internal medicine residents were surveyed regarding patient sign-outs at shift change. Data were used to design and implement interventions aimed at improving sign-out quality. This quasi-experimental project incorporated the Plan, Do, Study, Act methodology. Residents completed an anonymous electronic survey regarding experiences during sign-outs. Survey questions assessed structure, process, and outcome of sign-outs. Analysis of qualitative and quantitative data was performed; interventions were implemented based on survey findings. A total of 120 surveys (89% response) and 115 surveys (83% response) were completed by residents of 4 postgraduate years in response to the first (2008) and second (2009) survey requests, respectively. Approximately 79% of the respondents to the second survey indicated that postintervention sign-out systems were superior to preintervention systems. Results indicated improvement in specific areas of structure, process, and outcome. Survey-based modifications to existing sign-out systems effected measurable quality improvement in structure, process, and outcome.
About the specialized myocardial conducting tissue.
de Micheli Serra, Alfredo; Iturralde Torres, Pedro; Aranda Fraustro, Alberto
2013-01-01
The chronological succession of discoveries on the location and structure of the atrio-ventricular conducting system are described. The starting point of this system is located in the sinus atrial node, identified by the English scientists A. Keith and M. W. Flack in 1907. The atrioventricular conducting system was pointed out by the Swiss physician Wilhelm His Jr. in 1893. The atrioventricular node (AV) was first identified by the Japanese pathologist Sumao Tawara and his German professor Ludwig Aschoff in 1906. Likewise the structure and routes of the three internodal bundles are described. These bundles include: Bachmann's bundle (1916) connecting the right with the left atrium and the AV node; the middle Wenckebach's bundle (1910) and the posterior or Thörel's bundle (1910), extending from the region of the sinus atrial node towards the posterior margin of the AV node. Lastly, the ventricular left and right conduction systems are detailed. These include the main trunk and their peripheral subdivisions with respective networks. Regarding the controversial existence of the left middle subdivision, it can exist in animal and human hearts. Nevertheless, an intermediate left septal network of specialized fibers seems to act as a functional equivalent of this subdivision. Copyright © 2012 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.
A numerical study of mixing in supersonic combustors with hypermixing injectors
NASA Technical Reports Server (NTRS)
Lee, J.
1993-01-01
A numerical study was conducted to evaluate the performance of wall mounted fuel-injectors designed for potential Supersonic Combustion Ramjet (SCRAM-jet) engine applications. The focus of this investigation was to numerically simulate existing combustor designs for the purpose of validating the numerical technique and the physical models developed. Three different injector designs of varying complexity were studied to fully understand the computational implications involved in accurate predictions. A dual transverse injection system and two streamwise injector designs were studied. The streamwise injectors were designed with swept ramps to enhance fuel-air mixing and combustion characteristics at supersonic speeds without the large flow blockage and drag contribution of the transverse injection system. For this study, the Mass-Average Navier-Stokes equations and the chemical species continuity equations were solved. The computations were performed using a finite-volume implicit numerical technique and multiple block structured grid system. The interfaces of the multiple block structured grid systems were numerically resolved using the flux-conservative technique. Detailed comparisons between the computations and existing experimental data are presented. These comparisons show that numerical predictions are in agreement with the experimental data. These comparisons also show that a number of turbulence model improvements are needed for accurate combustor flowfield predictions.
A numerical study of mixing in supersonic combustors with hypermixing injectors
NASA Technical Reports Server (NTRS)
Lee, J.
1992-01-01
A numerical study was conducted to evaluate the performance of wall mounted fuel-injectors designed for potential Supersonic Combustion Ramjet (SCRAM-jet) engine applications. The focus of this investigation was to numerically simulate existing combustor designs for the purpose of validating the numerical technique and the physical models developed. Three different injector designs of varying complexity were studied to fully understand the computational implications involved in accurate predictions. A dual transverse injection system and two streamwise injector designs were studied. The streamwise injectors were designed with swept ramps to enhance fuel-air mixing and combustion characteristics at supersonic speeds without the large flow blockage and drag contribution of the transverse injection system. For this study, the Mass-Averaged Navier-Stokes equations and the chemical species continuity equations were solved. The computations were performed using a finite-volume implicit numerical technique and multiple block structured grid system. The interfaces of the multiple block structured grid systems were numerically resolved using the flux-conservative technique. Detailed comparisons between the computations and existing experimental data are presented. These comparisons show that numerical predictions are in agreement with the experimental data. These comparisons also show that a number of turbulence model improvements are needed for accurate combustor flowfield predictions.
Shell-corona microgels from double interpenetrating networks.
Rudyak, Vladimir Yu; Gavrilov, Alexey A; Kozhunova, Elena Yu; Chertovich, Alexander V
2018-04-18
Polymer microgels with a dense outer shell offer outstanding features as universal carriers for different guest molecules. In this paper, microgels formed by an interpenetrating network comprised of collapsed and swollen subnetworks are investigated using dissipative particle dynamics (DPD) computer simulations, and it is found that such systems can form classical core-corona structures, shell-corona structures, and core-shell-corona structures, depending on the subchain length and molecular mass of the system. The core-corona structures consisting of a dense core and soft corona are formed at small microgel sizes when the subnetworks are able to effectively separate in space. The most interesting shell-corona structures consist of a soft cavity in a dense shell surrounded with a loose corona, and are found at intermediate gel sizes; the area of their existence depends on the subchain length and the corresponding mesh size. At larger molecular masses the collapsing network forms additional cores inside the soft cavity, leading to the core-shell-corona structure.
The Dark Matter Crisis: Falsification of the Current Standard Model of Cosmology
NASA Astrophysics Data System (ADS)
Kroupa, P.
2012-06-01
The current standard model of cosmology (SMoC) requires The Dual Dwarf Galaxy Theorem to be true according to which two types of dwarf galaxies must exist: primordial dark-matter (DM) dominated (type A) dwarf galaxies, and tidal-dwarf and ram-pressure-dwarf (type B) galaxies void of DM. Type A dwarfs surround the host approximately spherically, while type B dwarfs are typically correlated in phase-space. Type B dwarfs must exist in any cosmological theory in which galaxies interact. Only one type of dwarf galaxy is observed to exist on the baryonic Tully-Fisher plot and in the radius-mass plane. The Milky Way satellite system forms a vast phase-space-correlated structure that includes globular clusters and stellar and gaseous streams. Other galaxies also have phase-space correlated satellite systems. Therefore, The Dual Dwarf Galaxy Theorem is falsified by observation and dynamically relevant cold or warm DM cannot exist. It is shown that the SMoC is incompatible with a large set of other extragalactic observations. Other theoretical solutions to cosmological observations exist. In particular, alone the empirical mass-discrepancy-acceleration correlation constitutes convincing evidence that galactic-scale dynamics must be Milgromian. Major problems with inflationary big bang cosmologies remain unresolved.
Spin Polarized Transport in Multilayer Structures with Complex Magnetic Configurations
NASA Astrophysics Data System (ADS)
Sahakyan, Avag; Poghosyan, Anahit; Movsesyan, Ruzan; Kocharian, Armen
The spin transport and spin polarization in a new class of multilayer structures are investigated for non-collinear and noncoplanar magnetic configurations containing repetitive magnetic layers. The magnetic configuration of the structure dictates the existence of certain degrees of freedom that determines magnetic transport and polarization properties. We consider magnetic structures in magnetic multilayers with canted spin configurations separated by non-magnetic quantum well so that the exchange interaction between the neighbor barriers can be ignored. Configurations of magnetizations in barriers include some structures consisting of two ''ferromagnetic'' or ''antiferromagnetic'' domains twisted relative to each other by a certain angle (angle noncollinearity). The similar system, formed from two noncollinear domains separated by canted ''magnetic defect'' is also considered. The above mentioned properties of these systems depend strongly on the type of magnetic configuration and variation of certain degrees of freedom. Simple theoretical approach with the transfer matrix method is carried out to understand and predict the magnetic properties of the multilayer systems. The work at California University Los Angeles was supported by the National Science Foundation-Partnerships for Research and Education in Materials under Grant DMR-1523588.
Koskinen, Heli I
2010-01-01
The Faculty of Veterinary Medicine at the University of Helsinki recognized the lack of systems to measure the quality of education. At the department level, this meant lack of systems to measure the quality of students' outcomes. The aim of this article was to compare the quality of outcomes of a final examination in veterinary radiology by calculating the correlations between traditional (quantitative scores traditionally given by veterinary teachers) and nontraditional (qualitative Structure of the Observed Learning Outcome, or SOLO, method) grading results. Evaluation of the quality of the questions is also included. The results indicate that SOLO offers criteria for quality evaluation, especially for questions. A correlation of 0.60 (p<0.01) existed between qualitative and quantitative estimations, and a correlation of 0.79 (p<0.01) existed between evaluators, both using traditional scores. Two suggestions for a better system to evaluate quality in the future: First, development of problem-solving skills during the learning process should also be assessed. Second, both the scoring of factual correctness of answers (knowledge) and the grammatical structure of an answer and the quality of presentation should be included in the quality evaluation process.
Systemic Constraints on Students' Appropriation of Reform Oriented Curriculum
ERIC Educational Resources Information Center
Ares, Nancy; Evans, Dawn M.; Harnischfeger, Alice M.
2018-01-01
We investigate 10th-grade Latinx and African American high school students' engagement in a reform-oriented curriculum designed to foster their critical social analysis of urban schooling. Students' designs of "ideal schools" based on their studies of their neighborhoods largely reproduced existing inequitable structures and practices of…
Online Schooling: A Cautionary Tale
ERIC Educational Resources Information Center
Saultz, Andrew; Fusarelli, Lance D.
2017-01-01
In this controversy piece, we portray online learning as growing too fast for existing regulatory structures to oversee and generally as having failed to live up to its potential. Operators, particularly for-profit operators, have generally not produced successful schools. We urge reforms of cyber schooling funding mechanisms, data systems, and…
47 CFR 90.241 - Radio call box operations.
Code of Federal Regulations, 2010 CFR
2010-10-01
... Safety Pool for operation of radio call boxes to be used by the public to request fire, police, ambulance... Public Safety Pool for highway call box systems subject to the following requirements: (1) Call box...) above the ground, the natural formation, or the existing man-made structure (other than an antenna...
47 CFR 90.241 - Radio call box operations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... Safety Pool for operation of radio call boxes to be used by the public to request fire, police, ambulance... Public Safety Pool for highway call box systems subject to the following requirements: (1) Call box...) above the ground, the natural formation, or the existing man-made structure (other than an antenna...
Feasibility study of modifications to BQM-34E drone for NASA research applications
NASA Technical Reports Server (NTRS)
James, H. A.
1972-01-01
The feasibility of modifying an existing supersonic drone into a free-flight research vehicle is examined. Appropriate structural and control system modifications, reliability and operational considerations, and ROM costs indicate that the BQM-34E drone is indeed suitable as a NASA research vehicle.
The Public School Monopoly: A Critical Analysis of Education and the State in American Society.
ERIC Educational Resources Information Center
Everhart, Robert B., Ed.
The following 14 essays consider relationships among schooling, education, and the state; alternatives to existing systems; and educating minorities and the disadvantaged: (1) "Growing Up Blighted: Reflections on the 'Secret Power' in the American Experience" (C. Burgess); (2) "The Evolving Political Structure of American…
Athene in Academe: Women Mentoring Women in the Academy.
ERIC Educational Resources Information Center
Stalker, Joyce
1994-01-01
Traditionally conceived, mentoring has a male orientation that ignores women's experience as "same" and "other" in academia and the problems of men mentoring women and of women mentors socializing mentees into acceptance of the patriarchal system. An alternative view values women's unique position and critiques existing power structures. (SK)
ERIC Educational Resources Information Center
Byeon, Jae-Kyung
2012-01-01
Despite a structured physical education system and related policies, dance education in Korea largely exists as a course in name only, without achieving its unique goals. It lacks standards within the physical education curriculum, which indicates that dance education is not conducted properly. Thus, the content and level of dance education vary…
CREDENTIALISM AND THE EDUCATION SYSTEM.
ERIC Educational Resources Information Center
MILLER, S.M.
EXISTING SOCIAL AND OCCUPATIONAL STRUCTURES SHOULD BE REMADE SO THAT CREDENTIALISM DOES NOT ARBITARILY BAR NEGROES AND THE POOR FROM ECONOMIC WELL-BEING AND SOCIAL MOBILITY. GRADUATION FROM A SCHOOL SIMPLY IMPLIES THAT ONE HAS FIT INTO THE PROPER EDUCATIONAL STRAITS AND DOES NOT NECESSARILY SIGNAL QUALITY PERFORMANCE. CREDENTIALISM AND ITS…
Report of the President's Committee On Student Involvement in the University.
ERIC Educational Resources Information Center
Benovich, Joseph B.; And Others
Originally established to consider expanded faculty and student involvement in the governance of Cleveland State University, the Committee decided to recommend changes within the existing governmental structure rather than encourage the establishment of a new system. Background material was studied, meetings were held and 2 questionnaires were…
Categorizing Drugs and Drug-Taking: A More Meaningful Approach.
ERIC Educational Resources Information Center
Gold, Robert S.; Duncan, David F.
This document reviews various definitions of the nature and classification of drugs. Difficulties with existing categorizations which use such bases as clinical utility, molecular structure, effects on the central nervous system, legality, and hazard potential are disucssed. A more meaningful categorization based on the availability and sources of…
Carbon markets proliferating despite difficulties, report notes
NASA Astrophysics Data System (ADS)
Showstack, Randy
2013-06-01
Although some existing carbon markets are facing structural issues and economic difficulties in Europe have put a damper on the European Union emissions trading system, new carbon pricing initiatives are developing rapidly, and these initiatives could help slow down greenhouse gas emissions, according to a 29 May report from the World Bank.
District Leadership Supporting PLC Implementation in a Rapid Growth District
ERIC Educational Resources Information Center
Tinsley, Laurie
2016-01-01
A growing body of work has emerged regarding the responsibilities required of district leaders in establishing plans that initiate and create conditions for sustainability of continuous improvement achieved through a systemic reform structure such as professional learning communities. However, limited research exists in respect to sustaining…
Automatic system for computer program documentation
NASA Technical Reports Server (NTRS)
Simmons, D. B.; Elliott, R. W.; Arseven, S.; Colunga, D.
1972-01-01
Work done on a project to design an automatic system for computer program documentation aids was made to determine what existing programs could be used effectively to document computer programs. Results of the study are included in the form of an extensive bibliography and working papers on appropriate operating systems, text editors, program editors, data structures, standards, decision tables, flowchart systems, and proprietary documentation aids. The preliminary design for an automated documentation system is also included. An actual program has been documented in detail to demonstrate the types of output that can be produced by the proposed system.
A design procedure for fan inflow control structures
NASA Technical Reports Server (NTRS)
Gedge, M. R.
1980-01-01
Significant differences exist in the noise generated by engine in flight and engines operating on the test stand. It was observed that these differences can be reduced by use of an inflow control structure (ICS) in the static test configuration. The results of the second phase of a three phase program are described and the results of a test program conducted to assess and modify various theoretical models, leading to the development of an ICS design system is summarized.
The Antarctic cold desert and the search for traces of life on Mars.
Friedmann, E I
1986-01-01
The cryptoendolithic microorganisms that live inside rocks in the frigid Ross Desert of Antarctica can serve as a terrestrial model for what may have happened to life forms on Mars when the planet became dry and cold. Trace fossils of microbial rock colonization exist in Antarctica, and similar structures could have formed on Mars. In some respects, such trace fossils could be an easier target for life-detection systems than fossils of cellular structures.
The Antarctic cold desert and the search for traces of life on Mars
NASA Technical Reports Server (NTRS)
Friedmann, E. I.
1986-01-01
The cryptoendolithic microoganisms that live inside rocks in the frigid Ross Desert of Antarctica can serve as a terrestrial model for what may have happened to life forms on Mars when the planet became dry and cold. Trace fossils of microbial rock colonization exist in Antarctica, and similar structures could have formed on Mars. In some respects, such trace fossils could be an easier target for life-detection systems than fossils of cellular structures.
1990-06-01
the form of structured objects was first pioneered by Marvin Minsky . In his seminal article " A Framework for Representing Knowl- edge" he introduced... Minsky felt that the existing methods of knowledge representation were too finely grained and he proposed that knowledge is more than just a...not work" in realistic, complex domains. ( Minsky , 1981, pp. 95-128) According to Minsky "A frame is a data-structure for representing a stereo- typed
Sustainability of health information systems in developing countries: the case of Fiji.
Soar, Jeffrey; Gow, Jeff; Caniogo, Vili
This paper examines the future sustainability of the Fijian Ministry of Health's (MoH) information and communication technology (ITC) system for patient management (PATIS). PATIS was developed with AusAID funding and, as the owner of the system, AusAID has no commercial competence or interest in further development of the system. Thus, the question that arises is: should Fiji adopt a commercially available patient administration system or retain the existing PATIS? In-depth consultations with senior executives and line managers of units that were major users of PATIS were undertaken. Semi-structured interviews and focus group discussion approaches were utilised. The consensus or majority views of the users were that the existing PATIS performed more than adequately. The future sustainability of the system is threatened by the lack of investment in resources (e.g. hardware maintenance and human resources) required to keep the system operating at its optimum. It was found that PATIS provides Fiji with a satisfactory patient administration system. The identified problems with the system are not related to the application per se but rather to an under-investment in resources for its utilisation.
NASA Astrophysics Data System (ADS)
Swenson, Donald A.
A new company, Ion Linac Systems, Inc., has been formed to promote the development, manufacture, and marketing of intense, RFI-based, Ion Linac Systems. The Rf Focused Interdigital (RFI) linac structure was invented by the author while at Linac Systems, LLC. The first step, for the new company, will be to correct a flaw in an existing RFI-based linac system and to demonstrate "good transmission" through the system. The existing system, aimed at the BNCT medical application, is designed to produce a beam of 2.5 MeV protons with an average beam current of 20 mA. In conjunction with a lithium target, it will produce an intense beam of epithermal neutrons. This system is very efficient, requiring only 180 kW of rf power to produce a 50 kW proton beam. In addition to the BNCT medical application, the RFI-based systems should represent a powerful neutron generator for homeland security, defence applications, cargo container inspection, and contraband detection. The timescale to the demonstration of "good transmission" is early fall of this year. Our website is www.ionlinacs.com.
Optical time-of-flight and absorbance imaging of biologic media.
Benaron, D A; Stevenson, D K
1993-03-05
Imaging the interior of living bodies with light may assist in the diagnosis and treatment of a number of clinical problems, which include the early detection of tumors and hypoxic cerebral injury. An existing picosecond time-of-flight and absorbance (TOFA) optical system has been used to image a model biologic system and a rat. Model measurements confirmed TOFA principles in systems with a high degree of photon scattering; rat images, which were constructed from the variable time delays experienced by a fixed fraction of early-arriving transmitted photons, revealed identifiable internal structure. A combination of light-based quantitative measurement and TOFA localization may have applications in continuous, noninvasive monitoring for structural imaging and spatial chemometric analysis in humans.
Optical Time-of-Flight and Absorbance Imaging of Biologic Media
NASA Astrophysics Data System (ADS)
Benaron, David A.; Stevenson, David K.
1993-03-01
Imaging the interior of living bodies with light may assist in the diagnosis and treatment of a number of clinical problems, which include the early detection of tumors and hypoxic cerebral injury. An existing picosecond time-of-flight and absorbance (TOFA) optical system has been used to image a model biologic system and a rat. Model measurements confirmed TOFA principles in systems with a high degree of photon scattering; rat images, which were constructed from the variable time delays experienced by a fixed fraction of early-arriving transmitted photons, revealed identifiable internal structure. A combination of light-based quantitative measurement and TOFA localization may have applications in continuous, noninvasive monitoring for structural imaging and spatial chemometric analysis in humans.
NASA Astrophysics Data System (ADS)
Lv, ZhuoKai; Yang, Tiejun; Zhu, Chunhua
2018-03-01
Through utilizing the technology of compressive sensing (CS), the channel estimation methods can achieve the purpose of reducing pilots and improving spectrum efficiency. The channel estimation and pilot design scheme are explored during the correspondence under the help of block-structured CS in massive MIMO systems. The block coherence property of the aggregate system matrix can be minimized so that the pilot design scheme based on stochastic search is proposed. Moreover, the block sparsity adaptive matching pursuit (BSAMP) algorithm under the common sparsity model is proposed so that the channel estimation can be caught precisely. Simulation results are to be proved the proposed design algorithm with superimposed pilots design and the BSAMP algorithm can provide better channel estimation than existing methods.
Structure and Binding of Ionic Clusters in Th and Zr Chloride Melts
NASA Astrophysics Data System (ADS)
Akdeniz, Z.; Tosi, M. P.
2001-11-01
We discuss microscopic ionic models for the structure and the binding of small clusters which may exist as structural units in molten ThCl4 and ZrCl4 and in their mixtures with alkali halides according to Raman scattering studies of Photiadis and Papatheodorou. The models are adjusted to the two isolated tetrahedral molecules. Appreciably higher ionicity is found for ThCl4 than for ZrCl4, and this fact underlies the strikingly different behaviour of the two systems in the dense liquid state -in particular, a molecular-type structure for molten ZrCl4 against a structure including charged oligomers in molten ThCl4.
Advanced Deployable Structural Systems for Small Satellites
NASA Technical Reports Server (NTRS)
Belvin, W. Keith; Straubel, Marco; Wilkie, W. Keats; Zander, Martin E.; Fernandez, Juan M.; Hillebrandt, Martin F.
2016-01-01
One of the key challenges for small satellites is packaging and reliable deployment of structural booms and arrays used for power, communication, and scientific instruments. The lack of reliable and efficient boom and membrane deployment concepts for small satellites is addressed in this work through a collaborative project between NASA and DLR. The paper provides a state of the art overview on existing spacecraft deployable appendages, the special requirements for small satellites, and initial concepts for deployable booms and arrays needed for various small satellite applications. The goal is to enhance deployable boom predictability and ground testability, develop designs that are tolerant of manufacturing imperfections, and incorporate simple and reliable deployment systems.
An improved design method for EPC middleware
NASA Astrophysics Data System (ADS)
Lou, Guohuan; Xu, Ran; Yang, Chunming
2014-04-01
For currently existed problems and difficulties during the small and medium enterprises use EPC (Electronic Product Code) ALE (Application Level Events) specification to achieved middleware, based on the analysis of principle of EPC Middleware, an improved design method for EPC middleware is presented. This method combines the powerful function of MySQL database, uses database to connect reader-writer with upper application system, instead of development of ALE application program interface to achieve a middleware with general function. This structure is simple and easy to implement and maintain. Under this structure, different types of reader-writers added can be configured conveniently and the expandability of the system is improved.
The neurobiology of psychopathy.
Glenn, Andrea L; Raine, Adrian
2008-09-01
Numerous studies have tackled the complex challenge of understanding the neural substrates of psychopathy, revealing that brain abnormalities exist on several levels and in several structures. As we discover more about complex neural networks, it becomes increasingly difficult to clarify how these systems interact with each other to produce the distinct pattern of behavioral and personality characteristics observed in psychopathy. The authors review the recent research on the neurobiology of psychopathy, beginning with molecular neuroscience work and progressing to the level of brain structures and their connectivity. Potential factors that may affect the development of brain impairments, as well as how some systems may be targeted for potential treatment, are discussed.
A System Approach to Advanced Practice Clinician Standardization and High Reliability.
Okuno-Jones, Susan; Siehoff, Alice; Law, Jennifer; Juarez, Patricia
Advanced practice clinicians (APCs) are an integral part of the health care team. Opportunities exist within Advocate Health Care to standardize and optimize APC practice across the system. To enhance the role and talents of APCs, an approach to role definition and optimization of practice and a structured approach to orientation and evaluation are shared. Although in the early stages of development, definition and standardization of accountabilities in a framework to support system changes are transforming the practice of APCs.
Model compilation for real-time planning and diagnosis with feedback
NASA Technical Reports Server (NTRS)
Barrett, Anthony
2005-01-01
This paper describes MEXEC, an implemented micro executive that compiles a device model that can have feedback into a structure for subsequent evaluation. This system computes both the most likely current device mode from n sets of sensor measurements and the n-1 step reconfiguration plan that is most likely to result in reaching a target mode - if such a plan exists. A user tunes the system by increasing n to improve system capability at the cost of real-time performance.
Design and implementation of a remote UAV-based mobile health monitoring system
NASA Astrophysics Data System (ADS)
Li, Songwei; Wan, Yan; Fu, Shengli; Liu, Mushuang; Wu, H. Felix
2017-04-01
Unmanned aerial vehicles (UAVs) play increasing roles in structure health monitoring. With growing mobility in modern Internet-of-Things (IoT) applications, the health monitoring of mobile structures becomes an emerging application. In this paper, we develop a UAV-carried vision-based monitoring system that allows a UAV to continuously track and monitor a mobile infrastructure and transmit back the monitoring information in real- time from a remote location. The monitoring system uses a simple UAV-mounted camera and requires only a single feature located on the mobile infrastructure for target detection and tracking. The computation-effective vision-based tracking solution based on a single feature is an improvement over existing vision-based lead-follower tracking systems that either have poor tracking performance due to the use of a single feature, or have improved tracking performance at a cost of the usage of multiple features. In addition, a UAV-carried aerial networking infrastructure using directional antennas is used to enable robust real-time transmission of monitoring video streams over a long distance. Automatic heading control is used to self-align headings of directional antennas to enable robust communication in mobility. Compared to existing omni-communication systems, the directional communication solution significantly increases the operation range of remote monitoring systems. In this paper, we develop the integrated modeling framework of camera and mobile platforms, design the tracking algorithm, develop a testbed of UAVs and mobile platforms, and evaluate system performance through both simulation studies and field tests.
Dependency visualization for complex system understanding
DOE Office of Scientific and Technical Information (OSTI.GOV)
Smart, J. Allison Cory
1994-09-01
With the volume of software in production use dramatically increasing, the importance of software maintenance has become strikingly apparent. Techniques now sought and developed for reverse engineering and design extraction and recovery. At present, numerous commercial products and research tools exist which are capable of visualizing a variety of programming languages and software constructs. The list of new tools and services continues to grow rapidly. Although the scope of the existing commercial and academic product set is quite broad, these tools still share a common underlying problem. The ability of each tool to visually organize object representations is increasingly impairedmore » as the number of components and component dependencies within systems increases. Regardless of how objects are defined, complex ``spaghetti`` networks result in nearly all large system cases. While this problem is immediately apparent in modem systems analysis involving large software implementations, it is not new. As will be discussed in Chapter 2, related problems involving the theory of graphs were identified long ago. This important theoretical foundation provides a useful vehicle for representing and analyzing complex system structures. While the utility of directed graph based concepts in software tool design has been demonstrated in literature, these tools still lack the capabilities necessary for large system comprehension. This foundation must therefore be expanded with new organizational and visualization constructs necessary to meet this challenge. This dissertation addresses this need by constructing a conceptual model and a set of methods for interactively exploring, organizing, and understanding the structure of complex software systems.« less
Cyclotron resonance of dirac fermions in InAs/GaSb/InAs quantum wells
DOE Office of Scientific and Technical Information (OSTI.GOV)
Krishtopenko, S. S.; Ikonnikov, A. V., E-mail: antikon@ipmras.ru; Maremyanin, K. V.
2017-01-15
The band structure of three-layer symmetric InAs/GaSb/InAs quantum wells confined between AlSb barriers is analyzed theoretically. It is shown that, depending on the thicknesses of the InAs and GaSb layers, a normal band structure, a gapless state with a Dirac cone at the center of the Brillouin zone, or inverted band structure (two-dimensional topological insulator) can be realized in this system. Measurements of the cyclotron resonance in structures with gapless band spectra carried out for different electron concentrations confirm the existence of massless Dirac fermions in InAs/GaSb/InAs quantum wells.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Martin, Mark A.
2002-04-15
Vegetation Management along the Rocky Reach – Maple Valley No. 1 Transmission Line ROW from structure 110/1 to the Maple Valley Substation. The transmission line is a 500 kV line. BPA proposes to clear targeted vegetation along access roads and around tower structures that may impede the operation and maintenance of the subject transmission line. BPA plans to conduct vegetation management along existing access road and around structure landings for the purpose of maintaining access to structures site. All work will be in accordance with the National Electrical Safety Code and BPA standards.
Dynamical and statistical behavior of discrete combustion waves: a theoretical and numerical study.
Bharath, Naine Tarun; Rashkovskiy, Sergey A; Tewari, Surya P; Gundawar, Manoj Kumar
2013-04-01
We present a detailed theoretical and numerical study of combustion waves in a discrete one-dimensional disordered system. The distances between neighboring reaction cells were modeled with a gamma distribution. The results show that the random structure of the microheterogeneous system plays a crucial role in the dynamical and statistical behavior of the system. This is a consequence of the nonlinear interaction of the random structure of the system with the thermal wave. An analysis of the experimental data on the combustion of a gasless system (Ti + xSi) and a wide range of thermite systems was performed in view of the developed model. We have shown that the burning rate of the powder system sensitively depends on its internal structure. The present model allows for reproducing theoretically the experimental data for a wide range of pyrotechnic mixtures. We show that Arrhenius' macrokinetics at combustion of disperse systems can take place even in the absence of Arrhenius' microkinetics; it can have a purely thermal nature and be related to their heterogeneity and to the existence of threshold temperature. It is also observed that the combustion of disperse systems always occurs in the microheterogeneous mode according to the relay-race mechanism.
Dynamical and statistical behavior of discrete combustion waves: A theoretical and numerical study
NASA Astrophysics Data System (ADS)
Bharath, Naine Tarun; Rashkovskiy, Sergey A.; Tewari, Surya P.; Gundawar, Manoj Kumar
2013-04-01
We present a detailed theoretical and numerical study of combustion waves in a discrete one-dimensional disordered system. The distances between neighboring reaction cells were modeled with a gamma distribution. The results show that the random structure of the microheterogeneous system plays a crucial role in the dynamical and statistical behavior of the system. This is a consequence of the nonlinear interaction of the random structure of the system with the thermal wave. An analysis of the experimental data on the combustion of a gasless system (Ti + xSi) and a wide range of thermite systems was performed in view of the developed model. We have shown that the burning rate of the powder system sensitively depends on its internal structure. The present model allows for reproducing theoretically the experimental data for a wide range of pyrotechnic mixtures. We show that Arrhenius’ macrokinetics at combustion of disperse systems can take place even in the absence of Arrhenius’ microkinetics; it can have a purely thermal nature and be related to their heterogeneity and to the existence of threshold temperature. It is also observed that the combustion of disperse systems always occurs in the microheterogeneous mode according to the relay-race mechanism.
Estimation of the behavior factor of existing RC-MRF buildings
NASA Astrophysics Data System (ADS)
Vona, Marco; Mastroberti, Monica
2018-01-01
In recent years, several research groups have studied a new generation of analysis methods for seismic response assessment of existing buildings. Nevertheless, many important developments are still needed in order to define more reliable and effective assessment procedures. Moreover, regarding existing buildings, it should be highlighted that due to the low knowledge level, the linear elastic analysis is the only analysis method allowed. The same codes (such as NTC2008, EC8) consider the linear dynamic analysis with behavior factor as the reference method for the evaluation of seismic demand. This type of analysis is based on a linear-elastic structural model subject to a design spectrum, obtained by reducing the elastic spectrum through a behavior factor. The behavior factor (reduction factor or q factor in some codes) is used to reduce the elastic spectrum ordinate or the forces obtained from a linear analysis in order to take into account the non-linear structural capacities. The behavior factors should be defined based on several parameters that influence the seismic nonlinear capacity, such as mechanical materials characteristics, structural system, irregularity and design procedures. In practical applications, there is still an evident lack of detailed rules and accurate behavior factor values adequate for existing buildings. In this work, some investigations of the seismic capacity of the main existing RC-MRF building types have been carried out. In order to make a correct evaluation of the seismic force demand, actual behavior factor values coherent with force based seismic safety assessment procedure have been proposed and compared with the values reported in the Italian seismic code, NTC08.
Study of structural reliability of existing concrete structures
NASA Astrophysics Data System (ADS)
Druķis, P.; Gaile, L.; Valtere, K.; Pakrastiņš, L.; Goremikins, V.
2017-10-01
Structural reliability of buildings has become an important issue after the collapse of a shopping center in Riga 21.11.2013, caused the death of 54 people. The reliability of a building is the practice of designing, constructing, operating, maintaining and removing buildings in ways that ensure maintained health, ward suffered injuries or death due to use of the building. Evaluation and improvement of existing buildings is becoming more and more important. For a large part of existing buildings, the design life has been reached or will be reached in the near future. The structures of these buildings need to be reassessed in order to find out whether the safety requirements are met. The safety requirements provided by the Eurocodes are a starting point for the assessment of safety. However, it would be uneconomical to require all existing buildings and structures to comply fully with these new codes and corresponding safety levels, therefore the assessment of existing buildings differs with each design situation. This case study describes the simple and practical procedure of determination of minimal reliability index β of existing concrete structures designed by different codes than Eurocodes and allows to reassess the actual reliability level of different structural elements of existing buildings under design load.
On the interplay between mathematics and biology. Hallmarks toward a new systems biology
NASA Astrophysics Data System (ADS)
Bellomo, Nicola; Elaiw, Ahmed; Althiabi, Abdullah M.; Alghamdi, Mohammed Ali
2015-03-01
This paper proposes a critical analysis of the existing literature on mathematical tools developed toward systems biology approaches and, out of this overview, develops a new approach whose main features can be briefly summarized as follows: derivation of mathematical structures suitable to capture the complexity of biological, hence living, systems, modeling, by appropriate mathematical tools, Darwinian type dynamics, namely mutations followed by selection and evolution. Moreover, multiscale methods to move from genes to cells, and from cells to tissue are analyzed in view of a new systems biology approach.
NASA Technical Reports Server (NTRS)
1974-01-01
An analysis of the requirements for the Earth Observatory Satellite (EOS) system specifications is presented. The analysis consists of requirements obtained from existing documentation and those derived from functional analysis. The requirements follow the hierarchy of program, mission, system, and subsystem. The code for designating specific requirements is explained. Among the subjects considered are the following: (1) the traffic model, (2) space shuttle related performance, (3) booster related performance, (4) the data collection system, (5) spacecraft structural tests, and (6) the ground support requirements.
Development of a wireless displacement measurement system using acceleration responses.
Park, Jong-Woong; Sim, Sung-Han; Jung, Hyung-Jo; Spencer, Billie F
2013-07-01
Displacement measurements are useful information for various engineering applications such as structural health monitoring (SHM), earthquake engineering and system identification. Most existing displacement measurement methods are costly, labor-intensive, and have difficulties particularly when applying to full-scale civil structures because the methods require stationary reference points. Indirect estimation methods converting acceleration to displacement can be a good alternative as acceleration transducers are generally cost-effective, easy to install, and have low noise. However, the application of acceleration-based methods to full-scale civil structures such as long span bridges is challenging due to the need to install cables to connect the sensors to a base station. This article proposes a low-cost wireless displacement measurement system using acceleration. Developed with smart sensors that are low-cost, wireless, and capable of on-board computation, the wireless displacement measurement system has significant potential to impact many applications that need displacement information at multiple locations of a structure. The system implements an FIR-filter type displacement estimation algorithm that can remove low frequency drifts typically caused by numerical integration of discrete acceleration signals. To verify the accuracy and feasibility of the proposed system, laboratory tests are carried out using a shaking table and on a three storey shear building model, experimentally confirming the effectiveness of the proposed system.
Development of a Wireless Displacement Measurement System Using Acceleration Responses
Park, Jong-Woong; Sim, Sung-Han; Jung, Hyung-Jo; Spencer, Billie F.
2013-01-01
Displacement measurements are useful information for various engineering applications such as structural health monitoring (SHM), earthquake engineering and system identification. Most existing displacement measurement methods are costly, labor-intensive, and have difficulties particularly when applying to full-scale civil structures because the methods require stationary reference points. Indirect estimation methods converting acceleration to displacement can be a good alternative as acceleration transducers are generally cost-effective, easy to install, and have low noise. However, the application of acceleration-based methods to full-scale civil structures such as long span bridges is challenging due to the need to install cables to connect the sensors to a base station. This article proposes a low-cost wireless displacement measurement system using acceleration. Developed with smart sensors that are low-cost, wireless, and capable of on-board computation, the wireless displacement measurement system has significant potential to impact many applications that need displacement information at multiple locations of a structure. The system implements an FIR-filter type displacement estimation algorithm that can remove low frequency drifts typically caused by numerical integration of discrete acceleration signals. To verify the accuracy and feasibility of the proposed system, laboratory tests are carried out using a shaking table and on a three storey shear building model, experimentally confirming the effectiveness of the proposed system. PMID:23881123
Strantza, Maria; Aggelis, Dimitrios G; de Baere, Dieter; Guillaume, Patrick; van Hemelrijck, Danny
2015-10-21
During the last decades, structural health monitoring (SHM) systems are used in order to detect damage in structures. We have developed a novel structural health monitoring approach, the so-called "effective structural health monitoring" (eSHM) system. The current SHM system is incorporated into a metallic structure by means of additive manufacturing (AM) and has the possibility to advance life safety and reduce direct operative costs. It operates based on a network of capillaries that are integrated into an AM structure. The internal pressure of the capillaries is continuously monitored by a pressure sensor. When a crack nucleates and reaches the capillary, the internal pressure changes signifying the existence of the flaw. The main objective of this paper is to evaluate the crack detection capacity of the eSHM system and crack location accuracy by means of various non-destructive testing (NDT) techniques. During this study, detailed acoustic emission (AE) analysis was applied in AM materials for the first time in order to investigate if phenomena like the Kaiser effect and waveform parameters used in conventional metals can offer valuable insight into the damage accumulation of the AM structure as well. Liquid penetrant inspection, eddy current and radiography were also used in order to confirm the fatigue damage and indicate the damage location on un-notched four-point bending AM metallic specimens with an integrated eSHM system. It is shown that the eSHM system in combination with NDT can provide correct information on the damage condition of additive manufactured metals.
Strantza, Maria; Aggelis, Dimitrios G.; de Baere, Dieter; Guillaume, Patrick; van Hemelrijck, Danny
2015-01-01
During the last decades, structural health monitoring (SHM) systems are used in order to detect damage in structures. We have developed a novel structural health monitoring approach, the so-called “effective structural health monitoring” (eSHM) system. The current SHM system is incorporated into a metallic structure by means of additive manufacturing (AM) and has the possibility to advance life safety and reduce direct operative costs. It operates based on a network of capillaries that are integrated into an AM structure. The internal pressure of the capillaries is continuously monitored by a pressure sensor. When a crack nucleates and reaches the capillary, the internal pressure changes signifying the existence of the flaw. The main objective of this paper is to evaluate the crack detection capacity of the eSHM system and crack location accuracy by means of various non-destructive testing (NDT) techniques. During this study, detailed acoustic emission (AE) analysis was applied in AM materials for the first time in order to investigate if phenomena like the Kaiser effect and waveform parameters used in conventional metals can offer valuable insight into the damage accumulation of the AM structure as well. Liquid penetrant inspection, eddy current and radiography were also used in order to confirm the fatigue damage and indicate the damage location on un-notched four-point bending AM metallic specimens with an integrated eSHM system. It is shown that the eSHM system in combination with NDT can provide correct information on the damage condition of additive manufactured metals. PMID:26506349
Multiscale structure in eco-evolutionary dynamics
NASA Astrophysics Data System (ADS)
Stacey, Blake C.
In a complex system, the individual components are neither so tightly coupled or correlated that they can all be treated as a single unit, nor so uncorrelated that they can be approximated as independent entities. Instead, patterns of interdependency lead to structure at multiple scales of organization. Evolution excels at producing such complex structures. In turn, the existence of these complex interrelationships within a biological system affects the evolutionary dynamics of that system. I present a mathematical formalism for multiscale structure, grounded in information theory, which makes these intuitions quantitative, and I show how dynamics defined in terms of population genetics or evolutionary game theory can lead to multiscale organization. For complex systems, "more is different," and I address this from several perspectives. Spatial host--consumer models demonstrate the importance of the structures which can arise due to dynamical pattern formation. Evolutionary game theory reveals the novel effects which can result from multiplayer games, nonlinear payoffs and ecological stochasticity. Replicator dynamics in an environment with mesoscale structure relates to generalized conditionalization rules in probability theory. The idea of natural selection "acting at multiple levels" has been mathematized in a variety of ways, not all of which are equivalent. We will face down the confusion, using the experience developed over the course of this thesis to clarify the situation.
Geophysical setting of the Wabash Valley fault system
Hildenbrand, T.G.; Ravat, D.
1997-01-01
Interpretation of existing regional magnetic and gravity data and new local high-resolution aeromagnetic data provides new insights on the tectonic history and structural development of the Wabash Valley Fault System in Illinois and Indiana. Enhancement of short-wavelength magnetic anomalies reveal numerous NW- to NNE-trending ultramafic dikes and six intrusive complexes (including those at Hicks Dome and Omaha Dome). Inversion models indicate that the interpreted dikes are narrow (???3 m), lie at shallow depths (500 km long and generally >50 km wide) and with deep basins (locally >3 km thick), the ancestral Wabash Valley faults express, in comparison, minor tectonic structures and probably do not represent a failed rift arm. There is a lack of any obvious relation between the Wabash Valley Fault System and the epicenters of historic and prehistoric earthquakes. Five prehistoric earthquakes lie conspicuously near structures associated with the Commerce geophysical lineament, a NE-trending magnetic and gravity lineament lying oblique to the Wabash Valley Fault System and possibly extending over 600 km from NE Arkansas to central Indiana.
Greiner, Leonard
1984-01-01
A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.
Greiner, Leonard
1981-01-01
A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.
Greiner, Leonard
1984-01-01
A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate intallation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.
Greiner, Leonard
1984-01-01
A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to faciliate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.
Emergency in-flight egress opening for general aviation aircraft. [pilot bailout
NASA Technical Reports Server (NTRS)
Bement, L. J.
1980-01-01
An emergency in-flight egress system was installed in a light general aviation airplane. The airplane had no provision for egress on the left side. To avoid a major structural redesign for a mechanical door, an add on 11.2 kg (24.6 lb) pyrotechnic-actuated system was developed to create an opening in the existing structure. The skin of the airplane was explosively severed around the side window, across a central stringer, and down to the floor, creating an opening of approximately 76 by 76 cm. The severed panel was jettisoned at an initial velocity of approximately 13.7 m/sec. System development included a total of 68 explosive severance tests on aluminum material using small samples, small and full scale flat panel aircraft structural mockups, and an actual aircraft fuselage. These tests proved explosive sizing/severance margins, explosive initiation, explosive product containment, and system dynamics. This technology is applicable to any aircraft of similar construction.
Blading System and Method For Controlling Structural Vibrations
NASA Technical Reports Server (NTRS)
Nguyen, Nhan (Inventor)
2000-01-01
A new blading system for controlling the structural vibrations in axial-flow compressors, turbines, or fans, as in aircraft engines and like turbomachines including a stator disc and a rotor disc is presented. The rotor disc defines several radial hubs that retain the rotor blading systems. Each blading system includes a blade formed of an airfoil, and a root attachment which is dimensioned to fit within, and to engage a corresponding hub. Viscoelastic dampers are selectively applied to the outer surfaces of the root attachment on which compressive or shear forces are likely to develop, intermediate the root attachment and the hub, for compression therebetween upon rotation of the rotor disc, in order to dampen structural vibrations. One advantage presented by the viscoelastic dampers lies in its simplicity, efficiency, cost effectiveness, and its ability to be retrofitted into existing turbomachines with minor surface treatment of the root attachments. Furthermore, since the dampers are not exposed to the inflowing airstream, they do not affect the aerodynamic performance of the turbomachine. Another feature of the damping system is that it provides a significant source of damping to minimize destructive structural vibrations, thereby increasing the durability of the turbomachine, and reducing acoustic noise accompanying high amplitude vibrations.
Travelling wave effects in large space structures
NASA Technical Reports Server (NTRS)
Vonflotow, A.
1983-01-01
Several aspects of travelling waves in Large Space Structures(LSS) are discussed. The dynamic similarity among LSS's, electric power systems, microwave circuits and communications network is noted. The existence of time lag between actuation and response is illuminated with the aid of simple examples, and their prediction is demonstrated. To prevent echoes, communications lines have matched terminations; this idea is applied to the design of dampers of one dimensional structures. Periodic structures act as mechanical band pass filters. Implications of this behavior are examined on a simple example. It is noted that the implication is twofold; continuum models of periodic lattice structures may err considerably; on the other hand, it is possible to design favorable transmission (and resonance) characteristics into the structure.
Thermodynamic Control of Two-Dimensional Molecular Ionic Nanostructures on Metal Surfaces
Jeon, Seokmin; Doak, Peter W.; Sumpter, Bobby G.; ...
2016-07-26
Bulk molecular ionic solids exhibit fascinating electronic properties, including electron correlations, phase transitions and superconducting ground states. In contrast, few of these phenomena have so far been observed in low-dimensional molecular structures, including thin films, nanoparticles and molecular blends, not in the least because most of such structures have so far been composed of nearly closed-shell molecules. It is therefore desirable to develop low-dimensional molecular structures of ionic molecules toward fundamental studies and potential applications. Here we present detailed analysis of monolayer-thick structures of the canonical TTF-TCNQ (tetrathiafulvalene 7,7,8,8-tetracyanoquinodimethane) system grown on low-index gold and silver surfaces. The most distinctivemore » property of the epitaxial growth is the wide abundance of stable TTF/TCNQ ratios, in sharp contrast to the predominance of 1:1 ratio in the bulk. We propose the existence of the surface phase-diagram that controls the structures of TTF-TCNQ on the surfaces, and demonstrate phase-transitions that occur upon progressively increasing the density of TCNQ while keeping the surface coverage of TTF fixed. Based on direct observations, we propose the binding motif behind the stable phases and infer the dominant interactions that enable the existence of the rich spectrum of surface structures. Finally, we also show that the surface phase diagram will control the epitaxy beyond monolayer coverage. Multiplicity of stable surface structures, the corollary rich phase diagram and the corresponding phase-transitions present an interesting opportunity for low-dimensional molecular systems, particularly if some of the electronic properties of the bulk can be preserved or modified in the surface phases.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Balser, S.; Sankar, S.; Miller, R.
In order to more fully integrate renewable resources, such as wind and solar, into the transmission system, additional capacity must be realized in the short term using the installed transmission capacity that exists today. The U.S. Department of Energy (DOE) and the National Renewable Energy Laboratory Transmission and Grid Integration Group supported this study to assemble the history of regulations and status of transmission technology to expand existing grid capacity. This report compiles data on various transmission technology methods and upgrades for increased capacity utilization of the existing transmission system and transmission corridors. The report discusses the technical merit ofmore » each method and explains how the method could be applied within the current regulatory structure to increase existing transmission conductor and/or corridor capacity. The history and current state of alternatives to new construction is presented for regulators, legislators, and other policy makers wrestling with issues surrounding integration of variable generation. Current regulations are assessed for opportunities to change them to promote grid expansion. To support consideration of these alternatives for expanding grid capacity, the report lists relevant rules, standards, and policy changes.« less
Phase and structural behavior of SmAlO{sub 3}–RAlO{sub 3} (R = Eu, Gd) systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ohon, N.; Vasylechko, L., E-mail: crystal-lov@polynet.lviv.ua; Prots, Yu.
2014-02-01
Highlights: • Continuous solid solutions exist in the SmAlO{sub 3}–RAlO{sub 3} (R = Eu, Gd) systems. • Lattice parameter crossover was found in solid solutions Sm{sub 1−x}R{sub x}AlO{sub 3} (R = Eu, Gd). • Thermally induced lattice crossovers occur in Sm{sub 0.9}R{sub 0.1}AlO{sub 3} at elevated temperatures. • First-order structural phase transition Pbnm↔R3{sup ¯}c was found in Sm{sub 1−x}R{sub x}AlO{sub 3} (R = Eu, Gd). • Phase diagram of the systems SmAlO{sub 3}–EuAlO{sub 3} and SmAlO{sub 3}–GdAlO{sub 3} has been constructed. - Abstract: Phase and structural behavior in the SmAlO{sub 3}–RAlO{sub 3} (R = Eu, Gd) systems has been studiedmore » in a whole concentration range by means of laboratory X-ray diffraction, in situ synchrotron powder diffraction and differential thermal analysis techniques. Continuous solid solutions with orthorhombic perovskite structure have been found in both systems. Peculiarity of the solid solutions of Sm{sub 1−x}Eu{sub x}AlO{sub 3} and Sm{sub 1−x}Gd{sub x}AlO{sub 3} is the existence of two lattice parameter crossovers in each system occurred at x{sub Eu} = 0.07 and 0.62 and at x{sub Gd} = 0.04 and 0.33, respectively. The temperature induced lattice crossovers in the Sm{sub 0.9}Eu{sub 0.1}AlO{sub 3} and Sm{sub 0.9}Gd{sub 0.1}AlO{sub 3} samples have been found at 387 and 922 K and at 501 and 894 K. First-order reversible structural phase transformations Pbnm↔R3{sup ¯}c have been detected in both systems at the elevated temperatures. The temperatures of these transitions increase linearly with the decreasing of the samarium content. Phase diagrams of the pseudo-binary systems SmAlO{sub 3}–EuAlO{sub 3} and SmAlO{sub 3}–GdAlO{sub 3} have been constructed.« less
Tiered Approach to Resilience Assessment.
Linkov, Igor; Fox-Lent, Cate; Read, Laura; Allen, Craig R; Arnott, James C; Bellini, Emanuele; Coaffee, Jon; Florin, Marie-Valentine; Hatfield, Kirk; Hyde, Iain; Hynes, William; Jovanovic, Aleksandar; Kasperson, Roger; Katzenberger, John; Keys, Patrick W; Lambert, James H; Moss, Richard; Murdoch, Peter S; Palma-Oliveira, Jose; Pulwarty, Roger S; Sands, Dale; Thomas, Edward A; Tye, Mari R; Woods, David
2018-04-25
Regulatory agencies have long adopted a three-tier framework for risk assessment. We build on this structure to propose a tiered approach for resilience assessment that can be integrated into the existing regulatory processes. Comprehensive approaches to assessing resilience at appropriate and operational scales, reconciling analytical complexity as needed with stakeholder needs and resources available, and ultimately creating actionable recommendations to enhance resilience are still lacking. Our proposed framework consists of tiers by which analysts can select resilience assessment and decision support tools to inform associated management actions relative to the scope and urgency of the risk and the capacity of resource managers to improve system resilience. The resilience management framework proposed is not intended to supplant either risk management or the many existing efforts of resilience quantification method development, but instead provide a guide to selecting tools that are appropriate for the given analytic need. The goal of this tiered approach is to intentionally parallel the tiered approach used in regulatory contexts so that resilience assessment might be more easily and quickly integrated into existing structures and with existing policies. Published 2018. This article is a U.S. government work and is in the public domain in the USA.
de Lamare, Rodrigo C; Sampaio-Neto, Raimundo
2008-11-01
A space-time adaptive decision feedback (DF) receiver using recurrent neural networks (RNNs) is proposed for joint equalization and interference suppression in direct-sequence code-division multiple-access (DS-CDMA) systems equipped with antenna arrays. The proposed receiver structure employs dynamically driven RNNs in the feedforward section for equalization and multiaccess interference (MAI) suppression and a finite impulse response (FIR) linear filter in the feedback section for performing interference cancellation. A data selective gradient algorithm, based upon the set-membership (SM) design framework, is proposed for the estimation of the coefficients of RNN structures and is applied to the estimation of the parameters of the proposed neural receiver structure. Simulation results show that the proposed techniques achieve significant performance gains over existing schemes.
A Review of Artificial Lateral Line in Sensor Fabrication and Bionic Applications for Robot Fish
Wang, Anyi; Wang, Xinbao; Liu, Peng
2016-01-01
Lateral line is a system of sense organs that can aid fishes to maneuver in a dark environment. Artificial lateral line (ALL) imitates the structure of lateral line in fishes and provides invaluable means for underwater-sensing technology and robot fish control. This paper reviews ALL, including sensor fabrication and applications to robot fish. The biophysics of lateral line are first introduced to enhance the understanding of lateral line structure and function. The design and fabrication of an ALL sensor on the basis of various sensing principles are then presented. ALL systems are collections of sensors that include carrier and control circuit. Their structure and hydrodynamic detection are reviewed. Finally, further research trends and existing problems of ALL are discussed. PMID:28115825
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1995-06-01
This report gives a preliminary cost benefit factor analysis for Automatic Highway Systems (AHS) implementation on a representative section of existing highway. The text describes the approach used to develop cost associated with the roadway portion of AHS and gives cost estimates for 5 basic implementation options: install `transparent equipment in roadway` that will give performance gains to those vehicles equipped to `see` it (e.g. magnetic nails); move towards separated roadway for AHS rumble strips or paint, then fully separated with either continuous barriers with dedicated entry/exit ramps or separate facility such an elevated structure; expand AHS capabilities further somore » AHS traffic can now use existing roadways with other traffic and formerly dedicated facilities can be converted to higher speed through traffic. However, the actual implementation will necessarily be a function of local roadway geometry, system demand, and a complex combination of other factors. Very few existing roadways can accommodate these specific conversions directly. Therefore, we have generated roadway retrofit options that can be used depending on local geometry to support this general evolution philosophy.« less
Assimilation of Spatially Sparse In Situ Soil Moisture Networks into a Continuous Model Domain
NASA Astrophysics Data System (ADS)
Gruber, A.; Crow, W. T.; Dorigo, W. A.
2018-02-01
Growth in the availability of near-real-time soil moisture observations from ground-based networks has spurred interest in the assimilation of these observations into land surface models via a two-dimensional data assimilation system. However, the design of such systems is currently hampered by our ignorance concerning the spatial structure of error afflicting ground and model-based soil moisture estimates. Here we apply newly developed triple collocation techniques to provide the spatial error information required to fully parameterize a two-dimensional (2-D) data assimilation system designed to assimilate spatially sparse observations acquired from existing ground-based soil moisture networks into a spatially continuous Antecedent Precipitation Index (API) model for operational agricultural drought monitoring. Over the contiguous United States (CONUS), the posterior uncertainty of surface soil moisture estimates associated with this 2-D system is compared to that obtained from the 1-D assimilation of remote sensing retrievals to assess the value of ground-based observations to constrain a surface soil moisture analysis. Results demonstrate that a fourfold increase in existing CONUS ground station density is needed for ground network observations to provide a level of skill comparable to that provided by existing satellite-based surface soil moisture retrievals.
NASA Astrophysics Data System (ADS)
Coşkun, Nart; Çakır, Özcan; Erduran, Murat; Arif Kutlu, Yusuf
2014-05-01
The Nevşehir Kale region located in the middle of Cappadocia with approximately cone shape is investigated for existence of an underground city using the geophysical methods of electrical resistivity and seismic surface wave tomography together. Underground cities are generally known to exist in Cappadocia. The current study has obtained important clues that there may be another one under the Nevşehir Kale region. Two-dimensional resistivity and seismic profiles approximately 4-km long surrounding the Nevşehir Kale are measured to determine the distribution of electrical resistivities and seismic velocities under the profiles. Several high resistivity anomalies with a depth range 8-20 m are discovered to associate with a systematic void structure beneath the region. Because of the high resolution resistivity measurement system currently employed we were able to isolate the void structure from the embedding structure. Low seismic velocity zones associated with the high resistivity depths are also discovered. Using three-dimensional visualization techniques we show the extension of the void structure under the measured profiles.
Improving RNA nearest neighbor parameters for helices by going beyond the two-state model.
Spasic, Aleksandar; Berger, Kyle D; Chen, Jonathan L; Seetin, Matthew G; Turner, Douglas H; Mathews, David H
2018-06-01
RNA folding free energy change nearest neighbor parameters are widely used to predict folding stabilities of secondary structures. They were determined by linear regression to datasets of optical melting experiments on small model systems. Traditionally, the optical melting experiments are analyzed assuming a two-state model, i.e. a structure is either complete or denatured. Experimental evidence, however, shows that structures exist in an ensemble of conformations. Partition functions calculated with existing nearest neighbor parameters predict that secondary structures can be partially denatured, which also directly conflicts with the two-state model. Here, a new approach for determining RNA nearest neighbor parameters is presented. Available optical melting data for 34 Watson-Crick helices were fit directly to a partition function model that allows an ensemble of conformations. Fitting parameters were the enthalpy and entropy changes for helix initiation, terminal AU pairs, stacks of Watson-Crick pairs and disordered internal loops. The resulting set of nearest neighbor parameters shows a 38.5% improvement in the sum of residuals in fitting the experimental melting curves compared to the current literature set.
Recent Updates to the CFD General Notation System (CGNS)
NASA Technical Reports Server (NTRS)
Rumsey, Christopher L.; Wedan, Bruce; Hauser, Thomas; Poinot, Marc
2012-01-01
The CFD General Notation System (CGNS) - a general, portable, and extensible standard for the storage and retrieval of computational fluid dynamics (CFD) analysis data has been in existence for more than a decade (Version 1.0 was released in May 1998). Both structured and unstructured CFD data are covered by the standard, and CGNS can be easily extended to cover any sort of data imaginable, while retaining backward compatibility with existing CGNS data files and software. Although originally designed for CFD, it is readily extendable to any field of computational analysis. In early 2011, CGNS Version 3.1 was released, which added significant capabilities. This paper describes these recent enhancements and highlights the continued usefulness of the CGNS methodology.
[On the approaches enhancing the structural effectiveness of regional public health system].
Uahakova, E I
2009-01-01
The particular technique of assessment of total extent of population consumption of medical care is discussed. The approach is based on the calculation of the sum of monetary equivalent units of rendering of medical care to population. The additional analysis of its structure according to the forms of medical care is specified. The approaches to the comparison between the existing structure of financing and factual cost criteria of unit of medical care provision on a particular territory are discussed. The example is given of calculation of possible economic benefit in the process of bring the ratio of medical care forms to conformity with the structure of its consumption recommended in the federal program of state guarantees of medical care in Russia. The recommendations are proposed how to reallocate the volumes of financing according the forms of medical care which will become the foundation of more balanced development of regional health care system.
International organizations to enable world-wide mobile satellite services
NASA Technical Reports Server (NTRS)
Anglin, Richard L., Jr.
1993-01-01
Numbers of systems exist or have been proposed to provide world-wide mobile satellite services (MSS). Developers of these systems have formulated institutional structures they consider most appropriate for profitable delivery of these services. MSS systems provide niche services and complement traditional telecommunications networks; they are not integrated into world-wide networks. To be successful, MSS system operators must be able to provide an integrated suite of services to support the increasing globalization, interconnectivity, and mobility of business. The critical issue to enabling 'universal roaming' is securing authority to provide MSS in all of the nations of the world. Such authority must be secured in the context of evolving trends in international telecommunications, and must specifically address issues of standardization, regulation and organization. Today, only one existing organization has such world-wide authority. The question is how proponents of new MSS systems and services can gain similar authority. Securing the appropriate authorizations requires that these new organizations reflect the objectives of the nations in which services are to be delivered.
NASA Technical Reports Server (NTRS)
Vukobratovich, Daniel; Richard, Ralph M.; Valente, Tina M.; Cho, Myung K.
1990-01-01
Scaling laws for light-weight optical systems are examined. A cubic relationship between mirror diameter and weight has been suggested and used by many designers of optical systems as the best description for all light-weight mirrors. A survey of existing light-weight systems in the open literature was made to clarify this issue. Fifty existing optical systems were surveyed with all varieties of light-weight mirrors including glass and beryllium structured mirrors, contoured mirrors, and very thin solid mirrors. These mirrors were then categorized and weight to diameter ratio was plotted to find a best curve for each case. A best fitting curve program tests nineteen different equations and ranks a goodness-to-fit for each of these equations. The resulting relationship found for each light-weight mirror category helps to quantify light-weight optical systems and methods of fabrication and provides comparisons between mirror types.
Access to medicines from a health system perspective
Bigdeli, Maryam; Jacobs, Bart; Tomson, Goran; Laing, Richard; Ghaffar, Abdul; Dujardin, Bruno; Van Damme, Wim
2013-01-01
Most health system strengthening interventions ignore interconnections between systems components. In particular, complex relationships between medicines and health financing, human resources, health information and service delivery are not given sufficient consideration. As a consequence, populations' access to medicines (ATM) is addressed mainly through fragmented, often vertical approaches usually focusing on supply, unrelated to the wider issue of access to health services and interventions. The objective of this article is to embed ATM in a health system perspective. For this purpose, we perform a structured literature review: we examine existing ATM frameworks, review determinants of ATM and define at which level of the health system they are likely to occur; we analyse to which extent existing ATM frameworks take into account access constraints at different levels of the health system. Our findings suggest that ATM barriers are complex and interconnected as they occur at multiple levels of the health system. Existing ATM frameworks only partially address the full range of ATM barriers. We propose three essential paradigm shifts that take into account complex and dynamic relationships between medicines and other components of the health system. A holistic view of demand-side constraints in tandem with consideration of multiple and dynamic relationships between medicines and other health system resources should be applied; it should be recognized that determinants of ATM are rooted in national, regional and international contexts. These are schematized in a new framework proposing a health system perspective on ATM. PMID:23174879
Facilitating the openEHR approach - organizational structures for defining high-quality archetypes.
Kohl, Christian Dominik; Garde, Sebastian; Knaup, Petra
2008-01-01
Using openEHR archetypes to establish an electronic patient record promises rapid development and system interoperability by using or adopting existing archetypes. However, internationally accepted, high quality archetypes which enable a comprehensive semantic interoperability require adequate development and maintenance processes. Therefore, structures have to be created involving different health professions. In the following we present a model which facilitates and governs distributed but cooperative development and adoption of archetypes by different professionals including peer reviews. Our model consists of a hierarchical structure of professional committees and descriptions of the archetype development process considering these different committees.
A data analysis expert system for large established distributed databases
NASA Technical Reports Server (NTRS)
Gnacek, Anne-Marie; An, Y. Kim; Ryan, J. Patrick
1987-01-01
A design for a natural language database interface system, called the Deductively Augmented NASA Management Decision support System (DANMDS), is presented. The DANMDS system components have been chosen on the basis of the following considerations: maximal employment of the existing NASA IBM-PC computers and supporting software; local structuring and storing of external data via the entity-relationship model; a natural easy-to-use error-free database query language; user ability to alter query language vocabulary and data analysis heuristic; and significant artificial intelligence data analysis heuristic techniques that allow the system to become progressively and automatically more useful.
Endogenous network of firms and systemic risk
NASA Astrophysics Data System (ADS)
Ma, Qianting; He, Jianmin; Li, Shouwei
2018-02-01
We construct an endogenous network characterized by commercial credit relationships connecting the upstream and downstream firms. Simulation results indicate that the endogenous network model displays a scale-free property which exists in real-world firm systems. In terms of the network structure, with the expansion of the scale of network nodes, the systemic risk increases significantly, while the heterogeneities of network nodes have no effect on systemic risk. As for firm micro-behaviors, including the selection range of trading partners, actual output, labor requirement, price of intermediate products and employee salaries, increase of all these parameters will lead to higher systemic risk.
Solar/hydrogen systems assessment. Volume 1: Solar/hydrogen systems for the 1985 - 2000 time frame
NASA Technical Reports Server (NTRS)
Foster, R. W.; Tison, R. R.; Escher, W. J. D.; Hanson, J. A.
1980-01-01
Opportunities for commercialization of systems capable of producing hydrogen from solar energy were studied. The hydrogen product costs that might be achieved by the four selected candidate systems was compared with the pricing structure and practices of the commodity gas market. Subsequently, product cost and market price match was noted to exist in the small user sector of the hydrogen marketplace. Barriers to and historical time lags in, commercialization of new technologies are reviewed. Recommendations for development and demonstration programs designed to accelerate the commercialization of the candidate systems are presented.
An overview of expert systems. [artificial intelligence
NASA Technical Reports Server (NTRS)
Gevarter, W. B.
1982-01-01
An expert system is defined and its basic structure is discussed. The knowledge base, the inference engine, and uses of expert systems are discussed. Architecture is considered, including choice of solution direction, reasoning in the presence of uncertainty, searching small and large search spaces, handling large search spaces by transforming them and by developing alternative or additional spaces, and dealing with time. Existing expert systems are reviewed. Tools for building such systems, construction, and knowledge acquisition and learning are discussed. Centers of research and funding sources are listed. The state-of-the-art, current problems, required research, and future trends are summarized.
Solar/hydrogen systems assessment. Volume 1: Solar/hydrogen systems for the 1985 - 2000 time frame
NASA Astrophysics Data System (ADS)
Foster, R. W.; Tison, R. R.; Escher, W. J. D.; Hanson, J. A.
1980-06-01
Opportunities for commercialization of systems capable of producing hydrogen from solar energy were studied. The hydrogen product costs that might be achieved by the four selected candidate systems was compared with the pricing structure and practices of the commodity gas market. Subsequently, product cost and market price match was noted to exist in the small user sector of the hydrogen marketplace. Barriers to and historical time lags in, commercialization of new technologies are reviewed. Recommendations for development and demonstration programs designed to accelerate the commercialization of the candidate systems are presented.
Chen, C L Philip; Liu, Zhulin
2018-01-01
Broad Learning System (BLS) that aims to offer an alternative way of learning in deep structure is proposed in this paper. Deep structure and learning suffer from a time-consuming training process because of a large number of connecting parameters in filters and layers. Moreover, it encounters a complete retraining process if the structure is not sufficient to model the system. The BLS is established in the form of a flat network, where the original inputs are transferred and placed as "mapped features" in feature nodes and the structure is expanded in wide sense in the "enhancement nodes." The incremental learning algorithms are developed for fast remodeling in broad expansion without a retraining process if the network deems to be expanded. Two incremental learning algorithms are given for both the increment of the feature nodes (or filters in deep structure) and the increment of the enhancement nodes. The designed model and algorithms are very versatile for selecting a model rapidly. In addition, another incremental learning is developed for a system that has been modeled encounters a new incoming input. Specifically, the system can be remodeled in an incremental way without the entire retraining from the beginning. Satisfactory result for model reduction using singular value decomposition is conducted to simplify the final structure. Compared with existing deep neural networks, experimental results on the Modified National Institute of Standards and Technology database and NYU NORB object recognition dataset benchmark data demonstrate the effectiveness of the proposed BLS.
Automated Structural Optimization System (ASTROS). Volume 2. User’s Manual
1988-04-07
preparation and on the use of advanced features that permit the user to modify the standard execution of ASTROS. f^Q^S*. ) I I J...software in considera- ble detail to direct the procedure to perform these alternative functions. The mechanisms by which these more advanced features are...grossly modify the existing capabilities of the system. These more advanced topics are treated in the Programmer’s and Application Manuals which
Nondestructive methods of integrating energy harvesting systems with structures
NASA Astrophysics Data System (ADS)
Inamdar, Sumedh; Zimowski, Krystian; Crawford, Richard; Wood, Kristin; Jensen, Dan
2012-04-01
Designing an attachment structure that is both novel and meets the system requirements can be a difficult task especially for inexperienced designers. This paper presents a design methodology for concept generation of a "parent/child" attachment system. The "child" is broadly defined as any device, part, or subsystem that will attach to any existing system, part, or device called the "parent." An inductive research process was used to study a variety of products, patents, and biological examples that exemplified the parent/child system. Common traits among these products were found and categorized as attachment principles in three different domains: mechanical, material, and field. The attachment principles within the mechanical domain and accompanying examples are the focus of this paper. As an example of the method, a case study of generating concepts for a bridge mounted wind energy harvester using the mechanical attachment principles derived from the methodology and TRIZ principles derived from Altshuller's matrix of contradictions is presented.
[Research progress and trend on grassland agroecology].
Ren, Jizhou; Li, Xianglin; Hou, Fujiang
2002-08-01
The connotation, progress, research frontiers and developmental trend of grassland agroecology are discussed in this paper. The interface theory, structure and function, coupling and discordance, and health assessment of grassland agroecosystems were recognized as the four research frontiers of the discipline. There exist three primary interfaces in a grassland agroecosystem, i.e., vegetation-site, grassland-animal and production-management. Research into a series of the ecological processes that occurred at these interfaces is the key to revealing the features of the system behavior. There are four sections in a grassland agroecosystem, i.e., pre-plant, plant, animal and post-biotic sections. System coupling and discordance are the two important concepts to describe interactions among the production sections. System coupling among the sections can lead to system improvement by exerting the potential of system capacity. Health of an ecosystem is a reflection of its structure and function, and health assessment is a measurement of its orderliness and service value.
Despont-Gros, Christelle; Bœuf, Christophe; Geissbuhler, Antoine; Lovis, Christian
2005-01-01
Evaluation of the technical feasibility of tight integration of the digital pen and paper technology in an existing computerized patient record.Technology: The digital pen is a normal pen able to record all actions of the user and to analyze a micro pattern printed on the paper. The digital paper is a normal paper printed with an almost invisible micro pattern of small dots encoding information such as position and identifiers. We report our experience in the implementation and the use of this technology in an existing large clinical information system for acquiring clinical information. It is possible to print uniquely identified forms using the digital paper technology. These forms can be pre-filled with clinical readable information about the patient. When care providers complete these forms using the digital pen, it is possible to acquire the data in a structured computerized patient record. The technology is easy to integrate in a component-based architecture based on Web Services. The digital pen and paper is a cost-effective technology that can be integrated in an existing clinical information system and allows fast and easy bedside clinical information acquisition without the need for an expensive infrastructure based on traditional portable devices or wireless devices.
Bridge Displacement Monitoring Method Based on Laser Projection-Sensing Technology
Zhao, Xuefeng; Liu, Hao; Yu, Yan; Xu, Xiaodong; Hu, Weitong; Li, Mingchu; Ou, Jingping
2015-01-01
Bridge displacement is the most basic evaluation index of the health status of a bridge structure. The existing measurement methods for bridge displacement basically fail to realize long-term and real-time dynamic monitoring of bridge structures, because of the low degree of automation and the insufficient precision, causing bottlenecks and restriction. To solve this problem, we proposed a bridge displacement monitoring system based on laser projection-sensing technology. First, the laser spot recognition method was studied. Second, the software for the displacement monitoring system was developed. Finally, a series of experiments using this system were conducted, and the results show that such a system has high measurement accuracy and speed. We aim to develop a low-cost, high-accuracy and long-term monitoring method for bridge displacement based on these preliminary efforts. PMID:25871716
A data management system for engineering and scientific computing
NASA Technical Reports Server (NTRS)
Elliot, L.; Kunii, H. S.; Browne, J. C.
1978-01-01
Data elements and relationship definition capabilities for this data management system are explicitly tailored to the needs of engineering and scientific computing. System design was based upon studies of data management problems currently being handled through explicit programming. The system-defined data element types include real scalar numbers, vectors, arrays and special classes of arrays such as sparse arrays and triangular arrays. The data model is hierarchical (tree structured). Multiple views of data are provided at two levels. Subschemas provide multiple structural views of the total data base and multiple mappings for individual record types are supported through the use of a REDEFINES capability. The data definition language and the data manipulation language are designed as extensions to FORTRAN. Examples of the coding of real problems taken from existing practice in the data definition language and the data manipulation language are given.
Gallucci, Luca; Menna, Costantino; Angrisani, Leopoldo; Asprone, Domenico; Moriello, Rosario Schiano Lo; Bonavolontà, Francesco; Fabbrocino, Francesco
2017-11-07
Maintenance strategies based on structural health monitoring can provide effective support in the optimization of scheduled repair of existing structures, thus enabling their lifetime to be extended. With specific regard to reinforced concrete (RC) structures, the state of the art seems to still be lacking an efficient and cost-effective technique capable of monitoring material properties continuously over the lifetime of a structure. Current solutions can typically only measure the required mechanical variables in an indirect, but economic, manner, or directly, but expensively. Moreover, most of the proposed solutions can only be implemented by means of manual activation, making the monitoring very inefficient and then poorly supported. This paper proposes a structural health monitoring system based on a wireless sensor network (WSN) that enables the automatic monitoring of a complete structure. The network includes wireless distributed sensors embedded in the structure itself, and follows the monitoring-based maintenance (MBM) approach, with its ABCDE paradigm, namely: accuracy, benefit, compactness, durability, and easiness of operations. The system is structured in a node level and has a network architecture that enables all the node data to converge in a central unit. Human control is completely unnecessary until the periodic evaluation of the collected data. Several tests are conducted in order to characterize the system from a metrological point of view and assess its performance and effectiveness in real RC conditions.
Ribbon phase in a phase-separated lyotropic lamellar-sponge mixture under shear flow
NASA Astrophysics Data System (ADS)
Cristobal, G.; Rouch, J.; Panizza, P.; Narayanan, T.
2001-07-01
We report the effect of shear flow on a phase-separated system composed of lyotropic lamellar (Lα) and sponge (L3) phases in a mixture of brine, surfactant, and cosurfactant. Optical microscopy, small-angle light, and x-ray scattering measurements are consistent with the existence of a steady state made of multilamellar ribbonlike structures aligned in the flow direction. At high shear rates, these ribbonlike structures become unstable and break up into monodisperse droplets resulting in a shear-thickening transition.
Behavior-based multi-robot collaboration for autonomous construction tasks
NASA Technical Reports Server (NTRS)
Stroupe, Ashley; Huntsberger, Terry; Okon, Avi; Aghazarian, Hrand; Robinson, Matthew
2005-01-01
The Robot Construction Crew (RCC) is a heterogeneous multi-robot system for autonomous construction of a structure through assembly of Long components. The two robot team demonstrates component placement into an existing structure in a realistic environment. The task requires component acquisition, cooperative transport, and cooperative precision manipulation. A behavior-based architecture provides adaptability. The RCC approach minimizes computation, power, communication, and sensing for applicability to space-related construction efforts, but the techniques are applicable to terrestrial construction tasks.
Literature Review of Shear Performance of Light-weight Steel Framing Wall Panels
NASA Astrophysics Data System (ADS)
Zhang, Zhuangnan; Liu, Shen; Liu, Hong
2018-03-01
In this paper, a comprehensive review of light-weight steel framing wall panels was carried out. The structure and force characteristics of light-weight steel framing wall panels were introduced. The testing and theoretical research results on the shear behaviour of light-weight steel framing wall panels were summarized in the domestic and foreign. And combined with the existing standards in China, the author's views and ideas are put forward to the problems in the research field of this kind of structural system.
SPAR improved structure/fluid dynamic analysis capability
NASA Technical Reports Server (NTRS)
Oden, J. T.; Pearson, M. L.
1983-01-01
The capability of analyzing a coupled dynamic system of flowing fluid and elastic structure was added to the SPAR computer code. A method, developed and adopted for use in SPAR utilizes the existing assumed stress hybrid plan element in SPAR. An operational mode was incorporated in SPAR which provides the capability for analyzing the flaw of a two dimensional, incompressible, viscous fluid within rigid boundaries. Equations were developed to provide for the eventual analysis of the interaction of such fluids with an elastic solid.
Preliminary scramjet design for hypersonic airbreathing missile application
NASA Technical Reports Server (NTRS)
Carlson, C. H.
1983-01-01
A conceptual design study of a scramjet engine was conducted for a hypersonic surface to air missile (HYSAM). The definition of the engine was based upon the requirements of accelerating the HYSAM from Mach 4 at 20,000 feet to Mach 6 at 100,000 feet and the cruise conditions at Mach 6. The resulting external and internal environmental conditions were used by various engineering disciplines performing design, stress and heat transfer analysis. A detailed structural analysis was conducted along with an indepth thermal analysis. Structurally all the components within the system exhibit positive margins of safety. A feasible concept was defined which uses state-of-the-art materials and existing TMC technology. The engine basically consists of a three dimensional carbon/carbon combustor/nozzle secured to an FS-85 columbium inlet. The carbon/carbon liner is sheathed with carbon felt insulation to thermally protect the FS-85 structure and skin. The thermal analysis of the engine indicates that a thermally viable configuration exists.
Damping characterization in large structures
NASA Technical Reports Server (NTRS)
Eke, Fidelis O.; Eke, Estelle M.
1991-01-01
This research project has as its main goal the development of methods for selecting the damping characteristics of components of a large structure or multibody system, in such a way as to produce some desired system damping characteristics. The main need for such an analytical device is in the simulation of the dynamics of multibody systems consisting, at least partially, of flexible components. The reason for this need is that all existing simulation codes for multibody systems require component-by-component characterization of complex systems, whereas requirements (including damping) often appear at the overall system level. The main goal was met in large part by the development of a method that will in fact synthesize component damping matrices from a given system damping matrix. The restrictions to the method are that the desired system damping matrix must be diagonal (which is almost always the case) and that interbody connections must be by simple hinges. In addition to the technical outcome, this project contributed positively to the educational and research infrastructure of Tuskegee University - a Historically Black Institution.
Barratt, Martin D
2004-11-01
Relationships between the structure and properties of chemicals can be programmed into knowledge-based systems such as DEREK for Windows (DEREK is an acronym for "Deductive Estimation of Risk from Existing Knowledge"). The DEREK for Windows computer system contains a subset of over 60 rules describing chemical substructures (toxophores) responsible for skin sensitisation. As part of the European Phototox Project, the rule base was supplemented by a number of rules for the prospective identification of photoallergens, either by extension of the scope of existing rules or by the generation of new rules where a sound mechanistic rationale for the biological activity could be established. The scope of the rules for photoallergenicity was then further refined by assessment against a list of chemicals identified as photosensitisers by the Centro de Farmacovigilancia de la Comunidad Valenciana, Valencia, Spain. This paper contains an analysis of the mechanistic bases of activity for eight important groups of photoallergens and phototoxins, together with rules for the prospective identification of the photobiological activity of new or untested chemicals belonging to those classes. The mechanism of action of one additional chemical, nitrofurantoin, is well established; however, it was deemed inappropriate to write a rule on the basis of a single chemical structure.
NASA Astrophysics Data System (ADS)
Gaviña, J. R.; Uy, F. A.; Carreon, J. D.
2017-06-01
There are over 8000 bridges in the Philippines today according to the Department of Public Works and Highways (DPWH). Currently, visual inspection is the most common practice in monitoring the structural integrity of bridges. However, visual inspections have proven to be insufficient in determining the actual health or condition of a bridge. Structural Health Monitoring (SHM) aims to give, in real-time, a diagnosis of the actual condition of the bridge. In this study, SmartBridge Sensor Nodes were installed on an existing concrete bridge with American Association of State Highway and Transportation Officials (AASHTO) Type IV Girders to gather vibration of the elements of the bridge. Also, standards on the effective installation of SmartBridge Sensor Nodes, such as location and orientation was determined. Acceleration readings from the sensor were then uploaded to a server, wherein they are monitored against certain thresholds, from which, the health of the bridge will be derived. Final output will be a portal or webpage wherein the information, health, and acceleration readings of the bridge will be available for viewing. With levels of access set for different types of users, the main users will have access to download data and reports. Data transmission and webpage access are available online, making the SHM system wireless.
Phan, Stephanie; Salentinig, Stefan; Hawley, Adrian; Boyd, Ben J
2015-10-01
Lipid-based formulations are gaining interest for use as drug delivery systems for poorly water-soluble drug compounds. During digestion, the lipolysis products self-assemble with endogenous surfactants in the gastrointestinal tract to form colloidal structures, enabling enhanced drug solubilisation. Although earlier studies in the literature focus on assembled equilibrium systems, little is known about structure formation under dynamic lipolysis conditions. The purpose of this study was to investigate the likely colloidal structure formation in the small intestine after the ingestion of lipids, under equilibrium and dynamic conditions. The structural aspects were studied using small angle X-ray scattering and dynamic light scattering, and were found to depend on lipid composition, lipid chain length, prandial state and emulsification. Incorporation of phospholipids and lipolysis products into bile salt micelles resulted in swelling of the structure. At insufficient bile salt concentrations, a co-existing lamellar phase was observed, due to a reduction in the solubilisation capacity for lipolysis products. Emulsification accelerated the rate of lipolysis and structure formation. Copyright © 2015 Elsevier B.V. All rights reserved.
Wade, J
1999-01-01
Sexual dimorphisms in the central nervous system exist in numerous vertebrate species, and in many cases these structural differences between males and females parallel differences in the display of reproductive behaviors. Often both the behavioral and anatomical differences are controlled by exposure to gonadal steroid hormones, either during ontogeny or in adulthood. This article reviews some of the evidence supporting the hypothesis that in mammals, testosterone or its metabolites regulate the structure and function of neural and muscle systems involved in the control of masculine sexual behaviors. It then describes data suggesting that the mechanisms regulating sexually dimorphic courtship systems in zebra finches and green anole lizards are not completely parallel to the mammalian systems. Finally, some directions for future study are suggested, with the hope that they will stimulate thought about the nature of comparisons made across vertebrate models when investigators are attempting to determine both which morphological sex differences are important to the control of the reproductive behaviors, and which mechanisms regulating both structure and function are widely employed or are unique.
System Theoretic Models for High Density VLSI Structures
1989-01-01
vector is also called a stable We first present a simple example to help visualize how vector of the AMN. The set of all stable vectors is denoted these...New York: Springer- Verlag. 1978. 1980 [34] B. De Finetti. "Funtzione catatteristica di un fenomeno aleato- , [16] W A Little. "The existence of
Dimensions and Domains of Organisational Effectiveness in Australian Higher Education.
ERIC Educational Resources Information Center
Lysons, Art
1990-01-01
Research in Australian higher education testing one theory of dimensions of organizational effectiveness is reviewed, and two theories are analyzed to develop a more comprehensive set of dimensions. The existing taxonomy is further defined, and the implications relating to recent structural adjustments in the higher education system are discussed.…
Back in the USSR: Path Dependence Effects in Student Representation in Russia
ERIC Educational Resources Information Center
Chirikov, Igor; Gruzdev, Ivan
2014-01-01
This paper analyses the current state of student representation in Russia as deeply rooted in the institutional structure of the Soviet higher education system. The study traces the origins of existing institutional arrangements for student representation at the level of university governance and analyses how representation practices have been…
String mediated phase transitions
NASA Technical Reports Server (NTRS)
Copeland, ED; Haws, D.; Rivers, R.; Holbraad, S.
1988-01-01
It is demonstrated from first principles how the existence of string-like structures can cause a system to undergo a phase transition. In particular, the role of topologically stable cosmic string in the restoration of spontaneously broken symmetries is emphasized. How the thermodynamic properties of strings alter when stiffness and nearest neighbor string-string interactions are included is discussed.
2014-02-26
left its existing structure in place, approving instead a shared - services directorate to consolidate common MHS functions (e.g., shared information...has seven main goals: (1) consolidate functions ( shared services ) common to DoD, (2) deliver more-integrated health care in areas with more than one
Legacies in material flux: Structural changes before long-term studies
D.J. Bain; M.B. Green; J. Campbell; J. Chamblee; S. Chaoka; J. Fraterrigo; S. Kaushal; S. Martin; T. Jordan; T. Parolari; B. Sobczak; D. Weller; W. M. Wollheim; E. Boose; J. Duncan; G. Gettel; B. Hall; P. Kumar; J. Thompson; J. Vose; E. Elliott; D. Leigh
2012-01-01
Legacy effects of past land use and disturbance are increasingly recognized, yet consistent definitions of and criteria for defining them do not exist. To address this gap in biological- and ecosystem-assessment frameworks, we propose a general metric for evaluating potential legacy effects, which are computed by normalizing altered system function persistence with...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-09
... Limitations Section (ALS) of the Instructions for Continued Airworthiness to incorporate life limits for... existing AD to continue to require revising the Airworthiness Limitations Section (ALS) of the Instructions... fatigue cracking in certain structures. The original NPRM also proposed to require revising the ALS of the...
An Exploratory Study of Software Cost Estimating at the Electronic Systems Division.
1976-07-01
action’. to improve the software cost Sestimating proces., While thin research was limited to the M.nD onvironment, the same types of problema may exist...Methods in Social Science. Now York: Random House, 1969. 57. Smith, Ronald L. Structured Programming Series (Vol. XI) - Estimating Software Project
ERIC Educational Resources Information Center
California Community Colleges, Sacramento. Office of the Chancellor.
A study was conducted by the Chancellor's Office of the California Community Colleges (CCC) to examine the consequences of existing fee policies and the likely impact of possible changes in the fee structures. The study simulated the consequences of three different fee proposals for the CCC system: an annual fee increase of $50 ($30 for those…
Spontaneous scale-free structure in adaptive networks with synchronously dynamical linking
NASA Astrophysics Data System (ADS)
Yuan, Wu-Jie; Zhou, Jian-Fang; Li, Qun; Chen, De-Bao; Wang, Zhen
2013-08-01
Inspired by the anti-Hebbian learning rule in neural systems, we study how the feedback from dynamical synchronization shapes network structure by adding new links. Through extensive numerical simulations, we find that an adaptive network spontaneously forms scale-free structure, as confirmed in many real systems. Moreover, the adaptive process produces two nontrivial power-law behaviors of deviation strength from mean activity of the network and negative degree correlation, which exists widely in technological and biological networks. Importantly, these scalings are robust to variation of the adaptive network parameters, which may have meaningful implications in the scale-free formation and manipulation of dynamical networks. Our study thus suggests an alternative adaptive mechanism for the formation of scale-free structure with negative degree correlation, which means that nodes of high degree tend to connect, on average, with others of low degree and vice versa. The relevance of the results to structure formation and dynamical property in neural networks is briefly discussed as well.
NASA Astrophysics Data System (ADS)
Nagy, Julia; Eilert, Tobias; Michaelis, Jens
2018-03-01
Modern hybrid structural analysis methods have opened new possibilities to analyze and resolve flexible protein complexes where conventional crystallographic methods have reached their limits. Here, the Fast-Nano-Positioning System (Fast-NPS), a Bayesian parameter estimation-based analysis method and software, is an interesting method since it allows for the localization of unknown fluorescent dye molecules attached to macromolecular complexes based on single-molecule Förster resonance energy transfer (smFRET) measurements. However, the precision, accuracy, and reliability of structural models derived from results based on such complex calculation schemes are oftentimes difficult to evaluate. Therefore, we present two proof-of-principle benchmark studies where we use smFRET data to localize supposedly unknown positions on a DNA as well as on a protein-nucleic acid complex. Since we use complexes where structural information is available, we can compare Fast-NPS localization to the existing structural data. In particular, we compare different dye models and discuss how both accuracy and precision can be optimized.
NASA Astrophysics Data System (ADS)
Huaqin, Wang; Shiyuan, Zhang; Tongzheng, Jin; Shiying, Han; Dirong, Qiu; Hao, Wang; Ningsheng, Zhou
In this paper the differences in diffraction intensities from some crystal planes in the X-ray diffraction patterns of high Tc Y-Ba-Cu-O system superconductors prepared by different processing conditions and the difference among various structure cells in references are interpreted using computer fitting. The results suggest that there exists two structure cells in the single phase YBa2Cu3O7-x samples. Both structure cells have the same crystal symmetry and almost the same lattice parameters, a=3.821Å, b=3.892Å and c=11.676Å, but the different distortion degree of Cu2-O plane. According to EPR spectra measured on the same samples, it is considered that the improvement of superconductivity for the samples prepared by two-step annealing in flowing oxygen may be related to concentration of the structure cell with more serious distortion on the Cu2-O plane.
NASA Astrophysics Data System (ADS)
Nadimpalli, Venkata K.; Nagy, Peter B.
2018-04-01
Ultrasonic Additive Manufacturing (UAM) is a solid-state layer by layer manufacturing process that utilizes vibration induced plastic deformation to form a metallurgical bond between a thin layer and an existing base structure. Due to the vibration based bonding mechanism, the quality of components at each layer depends on the geometry of the structure. In-situ monitoring during and between UAM manufacturing steps offers the potential for closed-loop control to optimize process parameters and to repair existing defects. One interface that is most prone to delamination is the base/build interface and often UAM component height and quality are limited by failure at the base/build interface. Low manufacturing temperatures and favorable orientation of typical interface defects in UAM make ultrasonic NDE an attractive candidate for online monitoring. Two approaches for in-situ NDE are discussed and the design of the monitoring system optimized so that the quality of UAM components is not affected by the addition of the NDE setup. Preliminary results from in-situ ultrasonic NDE indicate the potential to be utilized for online qualification, closed-loop control and offline certification of UAM components.
NASA Astrophysics Data System (ADS)
Ye, Qing; Mei, Lianfu; Shi, Hesheng; Shu, Yu; Camanni, Giovanni; Wu, Jing
2018-04-01
The basement structure of the Cenozoic Enping Sag, within the Pearl River Mouth Basin on the northern margin of South China Sea, is revealed by borehole-constrained high-quality 3D seismic reflection data. Such data suggest that the Enping Sag is bounded in the north by a low-angle normal fault. We interpret this low-angle normal fault to have developed as the result of the reactivation of a pre-existing thrust fault part of a pre-Cenozoic thrust system. This is demonstrated by the selective reactivation of the pre-existing thrust and by diffuse contractional deformation recognized from the accurate analysis of basement reflections. Another significant result of this study is the finding of some residual rift basins within the basement of the Enping Sag. Both the thrust system and the residual basins are interpreted to have developed after the emplacement of continental margin arc-related granitoids (J3-K1) that define the basement within the study area. Furthermore, seismic sections show that the pre-existing residual rift basins are offset by the main thrust fault and they are both truncated by the Tg unconformity. These structural relationships, interpreted in the frame of previous studies, help us to reconstruct a six-event structural evolution model for the Enping Sag from the late Mesozoic to the early Cenozoic. In particular, we interpret the residual rift basins to have formed as the result of back-arc extension due to the slab roll-back of the Paleo-Pacific Plate subduction in the early K2. The thrust system has recorded a compressional event in the late K2 that followed the back-arc extension in the SCS area. The mechanism of this compressional event is still to be clarified, and might be related to continuous subduction of the Paleo-Pacific Plate or to the continent-continent collision between a micro-continental block and the South China margin.
Coordination control of flexible manufacturing systems
NASA Astrophysics Data System (ADS)
Menon, Satheesh R.
One of the first attempts was made to develop a model driven system for coordination control of Flexible Manufacturing Systems (FMS). The structure and activities of the FMS are modeled using a colored Petri Net based system. This approach has the advantage of being able to model the concurrency inherent in the system. It provides a method for encoding the system state, state transitions and the feasible transitions at any given state. Further structural analysis (for detecting conflicting actions, deadlocks which might occur during operation, etc.) can be performed. The problem is also addressed of implementing and testing the behavior of existing dynamic scheduling approaches in simulations of realistic situations. A simulation architecture was proposed and performance evaluation was carried out for establishing the correctness of the model, stability of the system from a structural (deadlocks) and temporal (boundedness of backlogs) points of view, and for collection of statistics for performance measures such as machine and robot utilizations, average wait times and idle times of resources. A real-time implementation architecture for the coordination controller was also developed and implemented in a software simulated environment. Given the current technology of FMS control, the model-driven colored Petri net-based approach promises to develop a very flexible control environment.
Mirzoev, Tolib; Kane, Sumit
2018-01-01
Information from patient complaints - a widely accepted measure of patient satisfaction with services - can inform improvements in service quality, and contribute towards overall health systems performance. While analyses of data from patient complaints received much emphasis, there is limited published literature on key interventions to improve complaint management systems. The objectives are two-fold: first, to synthesise existing evidence and provide practical options to inform future policy and practice and, second, to identify key outstanding gaps in the existing literature to inform agenda for future research. We report results of review of the existing literature. Peer-reviewed published literature was searched in OVID Medline, OVID Global Health and PubMed. In addition, relevant citations from the reviewed articles were followed up, and we also report grey literature from the UK and the Netherlands. Effective interventions can improve collection of complaints (e.g. establishing easy-to-use channels and raising patients' awareness of these), analysis of complaint data (e.g. creating structures and spaces for analysis and learning from complaints data), and subsequent action (e.g. timely feedback to complainants and integrating learning from complaints into service quality improvement). No one single measure can be sufficient, and any intervention to improve patient complaint management system must include different components, which need to be feasible, effective, scalable, and sustainable within local context. Effective interventions to strengthen patient complaints systems need to be: comprehensive, integrated within existing systems, context-specific and cognizant of the information asymmetry and the unequal power relations between the key actors. Four gaps in the published literature represent an agenda for future research: limited understanding of contexts of effective interventions, absence of system-wide approaches, lack of evidence from low- and middle-income countries and absence of focused empirical assessments of behaviour of staff who manage patient complaints.