WorldWideScience

Sample records for model systems investigations

  1. Investigation of Interference Models for RFID Systems

    Directory of Open Access Journals (Sweden)

    Linchao Zhang

    2016-02-01

    Full Text Available The reader-to-reader collision in an RFID system is a challenging problem for communications technology. In order to model the interference between RFID readers, different interference models have been proposed, mainly based on two approaches: single and additive interference. The former only considers the interference from one reader within a certain range, whereas the latter takes into account the sum of all of the simultaneous interferences in order to emulate a more realistic behavior. Although the difference between the two approaches has been theoretically analyzed in previous research, their effects on the estimated performance of the reader-to-reader anti-collision protocols have not yet been investigated. In this paper, the influence of the interference model on the anti-collision protocols is studied by simulating a representative state-of-the-art protocol. The results presented in this paper highlight that the use of additive models, although more computationally intensive, is mandatory to improve the performance of anti-collision protocols.

  2. Investigation of $\\eta'N$ system using linear sigma model

    CERN Document Server

    Sakai, Shuntaro

    2016-01-01

    In this paper, we investigate the $\\eta'N$ system using the three-flavor linear sigma model including the effect of the flavor SU(3) symmetry breaking. The $\\eta'N$ bound state is found also in the case including the flavor symmetry braking and the coupling with the $\\eta N$ and $\\pi N$ channels. The $\\eta'N$ interaction becomes more attractive with the inclusion of the flavor symmetry breaking which causes the mixing between the singlet and octet scalar mesons. The existence of such a bound state would have some impact on the $\\eta'$-nucleus system, which is of interest from the theoretical and experimental viewpoint.

  3. Model system for investigating laser-induced subcellular microeffects

    Science.gov (United States)

    Huettmann, Gereon; Serbin, Jesper; Radt, Benno; Lange, Bjoern I.; Birngruber, Reginald

    2001-07-01

    Background: Laser induced protein denaturation is of fundamental interest for understanding the mechanisms of laser tissue interaction. Conjugates of nanoabsorbers coupled to proteins are presented as a model system for investigating ultrafast protein denaturation. Irradiation of the conjugates using repetitive picosecond laser pulses, which are only absorbed by the nanoabsorbers, could result in effects with a spatial confinement of less than 100 nm. Materials and Methods: Experiments were done with bovine intestinal alkaline phosphates (aP) coupled to 15 nm colloidal gold. This complex was irradiated at 527 nm wavelength and 35 ps pulse width with a varying number of pulses ranging form one up to 104. The radiant exposure per pulse was varied form 2 mJ/cm2 to 50 mJ/cm2. Denaturation was detected as a loss of protein function with the help of the fluorescence substrate 4MUP. Results and discussion: Irradiation did result in a steady decrease of the aP activity with increasing radiant exposures and increasing number of pulses. A maximal inactivation of 80% was reached with 104 pulses and 50 mJ/cm2 per pulse. The temperature in the particles and the surrounding water was calculated using Mie's formulas for the absorption of the nanometer gold particles and ana analytical solution of the equations for heat diffusion. With 50 mJ/cm2, the particles are heated above the melting point of gold. Since the temperature calculations strongly depend on changes in the state of matter of the particles and water, a very sophisticated thermal model is necessary to calculate exact temperatures. It is difficult to identify one of the possible mechanisms, thermal denaturation, photochemical denaturation or formation of micro bubbles from the dependance of the inactivation on pulse energy and number of applied pulses. Therefore, experiments are needed to further elucidate the damage mechanisms. In conclusion, denaturing proteins irreversibly via nanoabsorbers using picosecond laser

  4. Experimental Investigation and Modeling of Integrated Tri-generation Systems

    Science.gov (United States)

    Cetinkaya, Eda

    Energy demand in the world is increasing with population growth and higher living standards. Today, the need for energy requires a focus on renewable sources without abandoning fossil fuels. Efficient use of energy is one of the most important tasks in modern energy systems to achieve. In addition to the energy need, growing environmental concerns are linked with energy is emerged. Multi-purpose energy generation allows a higher efficiency by generating more outputs with the same input in the same system. Tri-generation systems are expected to provide at least three commodities, such as heating, cooling, desalination, storable fuel production and some other useful outputs, in addition to power generation. In this study, an experimental investigation of gasification is presented and two integrated tri-generation systems are proposed. The first integrated tri-generation system (System 1) utilizes solar energy as input and the outputs are power, fresh water and hot water. It consists of four sub-systems, namely solar power tower system, desalination system, Rankine cycle and organic Rankine cycle (ORC). The second integrated tri-generation system (System 2) utilizes coal and biomass as input and the outputs are power, fuel and hot water. It consists of five sub-systems: gasification plant, Brayton cycle, Rankine cycle, Fischer-Tropsch synthesis plant and an organic Rankine cycle (ORC). Experimental investigation includes coal and biomass gasification, where the experimental results of synthesis gas compositions are utilized in the analysis of the second systems. To maximize efficiency, heat losses from the system should be minimized through a recovery system to make the heat a useful commodity for other systems, such as ORCs which can utilize the low-grade heat. In this respect, ORCs are first analyzed for three different configurations in terms of energy and exergy efficiencies altering working fluids to increase the power output. Among two types of coal and one type

  5. Investigation of network-based information system model

    Energy Technology Data Exchange (ETDEWEB)

    Konrad, A.M.; Perez, M.; Rivera, J.; Rodriguez, Y.; Durst, M.J.; Merrill, D.W.; Holmes, H.H.

    1996-09-01

    The objective of the DOE-LBNL summer student research program in computer and information sciences focused on investigating database- based http-based information architectures, and implementation of a prototype using DOE`s Comprehensive Epidemiologic Data Resource (CEDR) metadata or Epidemiology Guide content. We were successful in identifying the components of such an information system, and appropriate configuration given the requirements, and in implementing a prototype. This work comprised investigation of various information systems architectures or variants, evaluation and selection of various tools, products, and packages, preparation of databases, database content, output formats, and graphical (World Wide Web- compatible) interfaces. We successfully prepared and demonstrated network access to content from both the CEDR structured documentation and from the DOD Epidemiology Guides (site archive records).

  6. Modeling of enterprise information systems implementation: a preliminary investigation

    Science.gov (United States)

    Yusuf, Yahaya Y.; Abthorpe, M. S.; Gunasekaran, Angappa; Al-Dabass, D.; Onuh, Spencer

    2001-10-01

    The business enterprise has never been in greater need of Agility and the current trend will continue unabated well into the future. It is now recognized that information system is both the foundation and a necessary condition for increased responsiveness. A successful implementation of Enterprise Resource Planning (ERP) can help a company to move towards delivering on its competitive objectives as it enables suppliers to reach out to customers beyond the borders of traditional market defined by geography. The cost of implementation, even when it is successful, could be significant. Bearing in mind the potential strategic benefits, it is important that the implementation project is managed effectively. To this end a project cost model against which to benchmark ongoing project expenditure versus activities completed has been proposed in this paper.

  7. An Investigation For Control Aspect Towards Modeled Dexterous Hand System

    Directory of Open Access Journals (Sweden)

    Rahul Roy ,

    2014-07-01

    Full Text Available The research domain of prosthetic technology has always remained a dialectic zone of creativity, yoking together technology and biomedical necessity. Any part of the human body replication procedure commences the prosthetic control science. Dexterity, adroitness in using the hands or body, is the prime or essential aspect in modeling dexterous hand. Simulation procedure implies to build up stability of the reference transfer function of Dexterous Hand. The present work deals with the discussion of stability criteria and simulation in discrete domain of Dexterous Hand.

  8. A framework and model system to investigate linear system behavior in Escherichia coli

    Science.gov (United States)

    2011-01-01

    Background The ability to compose biological systems from smaller elements that act independently of the other upon assembly may help make the forward engineering of biological systems practical. Engineering biology in this manner is made difficult by the inherent nonlinear response of organisms to genetic devices. Devices are inevitably coupled to one another in the cell because they share the same transcriptional machinery for expression. Thus, new properties can emerge when devices that had been characterized in isolation are expressed concurrently. We show in this report that, similar to physical systems, the Escherichia coli (E. coli) transcriptional system can exhibit linear behavior under "small" perturbation conditions. This, in turn, allows devices to be treated as independent modules. Results We developed a framework and model system consisting of three devices to investigate linear system behavior in E. coli. Our framework employed the transfer curve concept to determine the amount of nonlinearity elicited by the E. coli transcriptional system in response to the devices. To this effect, the model system was quantitatively characterized using real-time quantitative PCR to produce device transfer curves (DTCs). Two of the devices encoded the bacterial neomycin phosphotransferase II (nptII) and chloramphenicol acetyl transferase (cat), while the third encoded the jellyfish-originating green fluorescent protein (gfp). The gfp device was the most nonlinear in our system, with nptII and cat devices eliciting linear responses. Superposition experiments verified these findings, with independence among the three devices having been lost when gfp was present at copy numbers above the lowest one used. Conclusions We show that linear system behavior is possible in E. coli. Elucidation of the mechanism underlying the nonlinearity observed in gfp may lead to design rules that ensure linear system behavior, enabling the accurate prediction of the quantitative behavior

  9. Investigating modularity in the analysis of process algebra models of biochemical systems

    CERN Document Server

    Ciocchetta, Federica; Hillston, Jane; 10.4204/EPTCS.19.4

    2010-01-01

    Compositionality is a key feature of process algebras which is often cited as one of their advantages as a modelling technique. It is certainly true that in biochemical systems, as in many other systems, model construction is made easier in a formalism which allows the problem to be tackled compositionally. In this paper we consider the extent to which the compositional structure which is inherent in process algebra models of biochemical systems can be exploited during model solution. In essence this means using the compositional structure to guide decomposed solution and analysis. Unfortunately the dynamic behaviour of biochemical systems exhibits strong interdependencies between the components of the model making decomposed solution a difficult task. Nevertheless we believe that if such decomposition based on process algebras could be established it would demonstrate substantial benefits for systems biology modelling. In this paper we present our preliminary investigations based on a case study of the phero...

  10. Numerical modelling and experimental investigation of drug release from layered silicone matrix systems.

    Science.gov (United States)

    Snorradóttir, Bergthóra S; Jónsdóttir, Fjóla; Sigurdsson, Sven Th; Thorsteinsson, Freygardur; Másson, Már

    2013-07-16

    Medical devices and polymeric matrix systems that release drugs or other bioactive compounds are of interest for a variety of applications. The release of the drug can be dependent on a number of factors such as the solubility, diffusivity, dissolution rate and distribution of the solid drug in the matrix. Achieving the goal of an optimal release profile can be challenging when relying solely on traditional experimental work. Accurate modelling complementing experimentation is therefore desirable. Numerical modelling is increasingly becoming an integral part of research and development due to the significant advances in computer simulation technology. This work focuses on numerical modelling and investigation of multi-layered silicone matrix systems. A numerical model that can be used to model multi-layered systems was constructed and validated by comparison with experimental data. The model could account for the limited dissolution rate and effect of the drug distribution on the release profiles. Parametric study showed how different factors affect the characteristics of drug release. Multi-layered medical silicone matrices were prepared in special moulds, where the quantity of drug in each layer could be varied, and release was investigated with Franz-diffusion cell setup. Data for long-term release was fitted to the model and the full depletion of the system predicted. The numerical model constructed for this study, whose input parameters are the diffusion, effective dissolution rate and dimensional solubility coefficients, does not require any type of steady-state approximation. These results indicate that numerical model can be used as a design tool for development of controlled release systems such as drug-loaded medical devices.

  11. An Investigation of Factors Affecting Elementary School Students’ BMI Values Based on the System Dynamics Modeling

    Directory of Open Access Journals (Sweden)

    Tian-Syung Lan

    2014-01-01

    Full Text Available This study used system dynamics method to investigate the factors affecting elementary school students’ BMI values. The construction of the dynamic model is divided into the qualitative causal loop and the quantitative system dynamics modeling. According to the system dynamics modeling, this study consisted of research on the four dimensions: student’s personal life style, diet-relevant parenting behaviors, advocacy and implementation of school nutrition education, and students’ peer interaction. The results of this study showed that students with more adequate health concepts usually have better eating behaviors and consequently have less chance of becoming obese. In addition, this study also verified that educational attainment and socioeconomic status of parents have a positive correlation with students’ amounts of physical activity, and nutrition education has a prominent influence on changing students’ high-calorie diets.

  12. Investigation of a Ball Screw Feed Drive System Based on Dynamic Modeling for Motion Control

    Directory of Open Access Journals (Sweden)

    Yi-Cheng Huang

    2017-06-01

    Full Text Available This paper examines the frequency response relationship between the ball screw nut preload, ball screw torsional stiffness variations and table mass effect for a single-axis feed drive system. Identification for the frequency response of an industrial ball screw drive system is very important for the precision motion when the vibration modes of the system are critical for controller design. In this study, there is translation and rotation modes of a ball screw feed drive system when positioning table is actuated by a servo motor. A lumped dynamic model to study the ball nut preload variation and torsional stiffness of the ball screw drive system is derived first. The mathematical modeling and numerical simulation provide the information of peak frequency response as the different levels of ball nut preload, ball screw torsional stiffness and table mass. The trend of increasing preload will indicate the abrupt peak change in frequency response spectrum analysis in some mode shapes. This study provides an approach to investigate the dynamic frequency response of a ball screw drive system, which provides significant information for better control performance when precise motion control is concerned.

  13. Modelling small groundwater systems - the role of targeted field investigations and observational data in reducing model uncertainty

    Science.gov (United States)

    Abesser, Corinna; Hughes, Andrew; Boon, David

    2017-04-01

    Coastal dunes are delicate systems that are under threat from a variety of human and natural influences. Groundwater modelling can provide a better understanding of how these systems operate and can be a useful tool towards the effective management of a coastal dune system, e.g. through predicting impacts from climatic change, sea level rise and land use management. Because of their small size, typically 10 - 100 km2, models representing small dune aquifer systems are more sensitive to uncertainties in input data, model geometry and model parameterisation as well as to the availability of observational data. This study describes the development of a groundwater flow model for a small (8 km2) spit dune system, Braunton Burrows, on the Southwest coast of England, UK. The system has been extensively studied and its hydrology is thought to be well understood. However, model development revealed a high degree of uncertainty relating to model structure (definition of model boundary conditions) and parameterisation (e.g., transmissivity distributions within the model domain). An iterative approach was employed, integrating (1) sensitivity analyses, (2) targeted field investigations and (3) Monte Carlo simulations within a cycle of repeated interrogation of the model outputs, observed data and conceptual understanding. Assessment of "soft information" and targeted field investigations were an important part of this iterative modelling process. For example, a passive seismic survey (TROMINO®) provided valuable new data for the characterisation of concealed bedrock topography and thickness of superficial deposits. The data confirmed a generally inclined underlying wave cut rock shelf platform (as suggested by literature sources), revealed a buried valley, and led to a more detailed delineation of transmissivity zones within the model domain. Constructing models with increasingly more complex spatial distributions of transmissivity, resulted in considerable improvements in

  14. Investigation of the Nonlinear Model of the Cellular Population System Development

    Directory of Open Access Journals (Sweden)

    M. S. Vinogradova

    2014-01-01

    Full Text Available An isolated population system is considered which consists of two types of human stem cells: normal cells and cells with chromosomal anomalies (abnormal. In the paper the nonlinear dynamic model which describes dynamics of cell populations developing in vitro is elaborated. The model allows to investigate the processes of the formation of the abnormal cells population from the abnormal cells population of normal cells as well as joint development of these populations. The model takes into account the limited resources.An important feature of the developed model is the use of biological characteristics of processes in the cell population system, such as the proportion of cells, divided over a specified time, the proportion of cells whish are not divided, and which are "lost" and which are passed in the population of abnormal cells from the normal population. This approach allows a more detailed analysis of the impact of various "primary" parameters on the evolution of the population system.Under cultivation of cell populations in vitro a struggle for resources primarily affects the processes of the cell reproduction. This is reflected in the existence of the dividing cells frequency dependence of the total population of normal and abnormal cells. For the account of such dependencies different non-linear functions are typically used. However, the use of such non-linear relationships leads to the difficulties in finding confidence intervals for the estimates of the model parameters at subsequent stages of research. At the same time, the problem of the system parameters estimating and finding of the corresponding confidence intervals for estimates can be solved easy in case when the nonlinear system is linear with respect to the unknown parameters. In the paper it is achieved due to the piecewise linear approximation of nonlinear dependencies.An important feature of the model is a different view of the right part of the differential equations system

  15. Investigation of the Effects of a Nursing Information System by Using the Technology Acceptance Model.

    Science.gov (United States)

    Hsu, Hung-Hsiou; Wu, Ya-Hui

    2016-11-09

    The purposes of this study are to investigate the effectiveness of implementing a nursing information system and to discuss several issues affecting its successful deployment from the perspectives of nurses, the major users of the system. The methodology was based on the theory of the technology acceptance model. This study adopted a cross-sectional study method to survey and collect data. In total, 167 questionnaires were distributed to subjects. Approximately 94.6%, or 158 valid questionnaires, were collected. The data were analyzed using SPSS and PLS software.The data analysis indicated that the factors that most significantly influenced the willingness of nurses to use the nursing information system were their degrees of satisfaction with the system and their perceptions of its usefulness. A nursing information system that can provide functions that are useful and convenient and that facilitate the avoidance of tedious repetitive writing and improve the quality of provided care can encourage nurse satisfaction with the system and thus stimulate their interest in using it for their work. The ease of use of the system can also affect the willingness of nurses to use it.

  16. Pumped storage system model and experimental investigations on S-induced issues during transients

    Science.gov (United States)

    Zeng, Wei; Yang, Jiandong; Hu, Jinhong

    2017-06-01

    Because of the important role of pumped storage stations in the peak regulation and frequency control of a power grid, pump turbines must rapidly switch between different operating modes, such as fast startup and load rejection. However, pump turbines go through the unstable S region in these transition processes, threatening the security and stability of the pumped storage station. This issue has mainly been investigated through numerical simulations, while field experiments generally involve high risks and are difficult to perform. Therefore, in this work, the model test method was employed to study S-induced security and stability issues for a pumped storage station in transition processes. First, a pumped storage system model was set up, including the piping system, model units, electrical control systems and measurement system. In this model, two pump turbines with different S-shaped characteristics were installed to determine the influence of S-shaped characteristics on transition processes. The model platform can be applied to simulate any hydraulic transition process that occurs in real power stations, such as load rejection, startup, and grid connection. On the experimental platform, the S-shaped characteristic curves were measured to be the basis of other experiments. Runaway experiments were performed to verify the impact of the S-shaped characteristics on the pump turbine runaway stability. Full load rejection tests were performed to validate the effect of the S-shaped characteristics on the water-hammer pressure. The condition of one pump turbine rejecting its load after another defined as one-after-another (OAA) load rejection was performed to validate the possibility of S-induced extreme draft tube pressure. Load rejection experiments with different guide vane closing schemes were performed to determine a suitable scheme to adapt the S-shaped characteristics. Through these experiments, the threats existing in the station were verified, the

  17. Investigating Patterns for the Process-Oriented Modelling and Simulation of Space in Complex Systems

    OpenAIRE

    Sampson, Adam T.; Welch, Peter H.; Warren, Douglas N.; Andrews, Paul S.; Bjørndalen, John Markus; Stepney, Susan; Timmis, Jon

    2008-01-01

    Complex systems modelling and simulation is becoming increasingly important to numerous disciplines. The CoSMoS project aims to produce a unified infrastructure for modelling and simulating all sorts of complex systems, making use of design patterns and the process-oriented programming model. We provide a description of CoSMoS and present a case study into the modelling of space in complex systems. We describe how two models - absolute geometric space and relational network space - can be cap...

  18. CFD modelling and experimental investigation of an ejector refrigeration system using methanol as the working fluid

    Energy Technology Data Exchange (ETDEWEB)

    Riffat, S.B.; Omer, S.A. [Nottingham Univ., School of the Built Environment, Nottingham (United Kingdom)

    2001-07-01

    This paper presents results of computational fluid dynamic (CFD) analysis and experimental investigation of an ejector refrigeration system using methanol as the working fluid. The CFD modelling was used to investigate the effect of the relative position of the primary nozzle exit within the mixing chamber on the performance of the ejector. The results of the CFD were used to obtain the optimum geometry of the ejector, which was then used to design, construct and test a small-scale experimental ejector refrigeration system. Methanol was used as the working fluid, as it has the advantage of being an 'environmentally friendly' refrigerant that does not contribute to global warming and ozone layer depletion. In addition, use of methanol allows the ejector refrigeration system to produce cooling at temperatures below the freezing point of the water, which of course would not be possible with a water ejector refrigeration system. CFD results showed that positioning the nozzle exit at least 0.21 length of the mixing chamber throat's diameter upstream of the entrance of the mixing chamber gave better performance than pushing it into the mixing chamber. Experimental values of coefficient of performance (COP) between 0.2 and 0.4 were obtained at operating conditions achievable using low-grade heat such as solar energy and waste heat. (Author)

  19. Investigating the role of biofilms in trihalomethane formation in water distribution systems with a multicomponent model.

    Science.gov (United States)

    Abokifa, Ahmed A; Yang, Y Jeffrey; Lo, Cynthia S; Biswas, Pratim

    2016-11-01

    Biofilms are ubiquitous in the pipes of drinking water distribution systems (DWDSs), and recent experimental studies revealed that the chlorination of the microbial carbon associated with the biofilm contributes to the total disinfection by-products (DBPs) formation with distinct mechanisms from those formed from precursors derived from natural organic matter (NOM). A multiple species reactive-transport model was developed to explain the role of biofilms in DBPs formation by accounting for the simultaneous transport and interactions of disinfectants, organic compounds, and biomass. Using parameter values from experimental studies in the literature, the model equations were solved to predict chlorine decay and microbial regrowth dynamics in an actual DWDS, and trihalomethanes (THMs) formation in a pilot-scale distribution system simulator. The model's capability of reproducing the measured concentrations of free chlorine, suspended biomass, and THMs under different hydrodynamic and temperature conditions was demonstrated. The contribution of bacteria-derived precursors to the total THMs production was found to have a significant dependence on the system's hydraulics, seasonal variables, and the quality of the treated drinking water. Under system conditions that promoted fast bacterial re-growth, the transformation of non-microbial into microbial carbon DBP precursors by the biofilms showed a noticeable effect on the kinetics of THMs formation, especially when a high initial chlorine dose was applied. These conditions included elevated water temperature and high concentrations of nutrients in the influent water. The fraction of THMs formed from microbial sources was found to reach a peak of 12% of the total produced THMs under the investigated scenarios. The results demonstrated the importance of integrating bacterial regrowth dynamics in predictive DBPs formation models. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Investigation and modelling of thermal conditions in low flow SDHW systems

    Energy Technology Data Exchange (ETDEWEB)

    Shah, L.J.

    1999-07-01

    The purpose of this study was to characterise the thermal conditions in low flow SDHW systems. As the heat storage has proved to be the most important system component, there has been an emphasis on this component in the study. A literature survey revealed that the mantle tank heat storage type is one of the most promising storage designs and therefore only the mantle tank is investigated in this study. To optimise the design of mantle tanks and low flow SDHW systems, it was found necessary to understand how the thermal stratification is built up in the heat storage. In addition, it was necessary to model the flow and heat transfer in the tanks. Due to the complexity of the problems, CFD-models were used to take mantle tanks into calculation. Two CFD programs were used to model the mantle tank: CFX and Fluent. As the CFD-models formed the basis for the theoretical work, they were validated with experiments. In this study, both thermal measurements and experimentally visualised flow patterns were compared with CFD-predictions. The experimental flow visualisation was carried out with Particle image Velocimetry (PIV). With a transparent glass mantle tank, the structures in the mantle were visualised and compared with the CFD-predicted flow structures in the mantle. The results showed that the mantle flow was highly dominated by buoyancy and the CFD-models were able to model this flow. With a steel mantle tank, different dynamic thermal experiments were carried out in a heat storage test facility. These results were used to evaluate the CFD-predicted temperatures. Inner tank and mantle outlet temperatures were compared to the similar CFD-predictions and a good degree of similarity was found between measured and calculated temperatures. With the verified CFX models a parameter analysis was carried out. Based on this analysis, two Nusselt-Rayleigh heat transfer correlations were developed - one for the convective heat transfer in the mantle and one for the convective

  1. Rational design of a bimodular model system for the investigation of heterocyclization in nonribosomal peptide biosynthesis.

    Science.gov (United States)

    Duerfahrt, Thomas; Eppelmann, Katrin; Müller, Rolf; Marahiel, Mohamed A

    2004-02-01

    Cyclization (Cy) domains in NRPS catalyze the heterocyclization of cysteine and serine/threonine to thiazoline and oxazoline rings. A model system consisting of the first two modules of bacitracin synthetase A fused to the thioesterase (Te) domain of tyrocidine synthetase was constructed (BacA1-2-Te) and shown to be active in production of the heterocyclic IleCys(thiazoline). Based on this model system, the feasibility of Cy domain module fusions was investigated by replacing the BacA2 Cy-A-PCP-module with modules of MbtB and MtaD from the biosynthesis systems of mycobactin and myxothiazol, revealing the formation of novel heterocyclic dipeptides. To dissect the reaction sequence of the Cy domain in peptide bond formation and heterocyclization, several residues of the BacA1-2-Te Cy domain were analyzed by mutagenesis. Two mutants exhibited formation of the noncyclic dipeptide, providing clear evidence for the independence of condensation and cyclization.

  2. The development and testing of a 2D laboratory seismic modelling system for heterogeneous structure investigations

    Science.gov (United States)

    Mo, Yike; Greenhalgh, Stewart A.; Robertsson, Johan O. A.; Karaman, Hakki

    2015-05-01

    Lateral velocity variations and low velocity near-surface layers can produce strong scattered and guided waves which interfere with reflections and lead to severe imaging problems in seismic exploration. In order to investigate these specific problems by laboratory seismic modelling, a simple 2D ultrasonic model facility has been recently assembled within the Wave Propagation Lab at ETH Zurich. The simulated geological structures are constructed from 2 mm thick metal and plastic sheets, cut and bonded together. The experiments entail the use of a piezoelectric source driven by a pulse amplifier at ultrasonic frequencies to generate Lamb waves in the plate, which are detected by piezoelectric receivers and recorded digitally on a National Instruments recording system, under LabVIEW software control. The 2D models employed were constructed in-house in full recognition of the similitude relations. The first heterogeneous model features a flat uniform low velocity near-surface layer and deeper dipping and flat interfaces separating different materials. The second model is comparable but also incorporates two rectangular shaped inserts, one of low velocity, the other of high velocity. The third model is identical to the second other than it has an irregular low velocity surface layer of variable thickness. Reflection as well as transmission experiments (crosshole & vertical seismic profiling) were performed on each model. The two dominant Lamb waves recorded are the fundamental symmetric mode (non-dispersive) and the fundamental antisymmetric (flexural) dispersive mode, the latter normally being absent when the source transducer is located on a model edge but dominant when it is on the flat planar surface of the plate. Experimental group and phase velocity dispersion curves were determined and plotted for both modes in a uniform aluminium plate. For the reflection seismic data, various processing techniques were applied, as far as pre-stack Kirchhoff migration. The

  3. Personal Investigations Processing System

    Data.gov (United States)

    US Agency for International Development — PIPS is a system that maintains the Security/Suitability Investigations Index (SII) for OPM. It contains over 11 million background investigation records of Federal...

  4. Novel perfused compression bioreactor system as an in vitro model to investigate fracture healing

    Directory of Open Access Journals (Sweden)

    Waldemar eHoffmann

    2015-02-01

    Full Text Available Secondary bone fracture healing is a physiological process that leads to functional tissue regeneration via endochondral bone formation. In vivo studies have demonstrated that early mobilization and the application of mechanical loads enhances the process of fracture healing. However, the influence of specific mechanical stimuli and particular effects during specific phases of fracture healing remain to be elucidated. In this work, we have developed and provided proof-of-concept of an in vitro human organotypic model of physiological loading of a cartilage callus, based on a novel perfused compression bioreactor system (PCB. We then used the fracture callus model to investigate the regulatory role of dynamic mechanical loading. Our findings provide a proof-of-principle that dynamic mechanical loading applied by the PCB can enhance the maturation process of mesenchymal stromal cells towards late hypertrophic chondrocytes and the mineralization of the deposited extracellular matrix. The PCB provides a promising tool to study fracture healing and for the in vitro assessment of alternative fracture treatments based on engineered tissue grafts or pharmaceutical compounds, allowing for the reduction of animal experiments.

  5. Investigation of proper modeling of very dense granular flows in the recirculation system of CFBs

    Institute of Scientific and Technical Information of China (English)

    Aristeidis Nikolopoulos; Nikos Nikolopoulos; Nikos Varveris; Sotirios Karellas; Panagiotis Grammelis; Emmanuel Kakaras

    2012-01-01

    The aim of this paper is the development of new models and/or the improvement of existing numerical models,used for simulating granular flow in CFB (circulating fluidized bed) recirculation systems.Most recent models follow the TFM (two-fluid model) methodology,but they cannot effectively simulate the inter-particle friction forces in the recirculation system,because the respective stress tensor does not incorporate compressibility of flow due to change of effective particle density.As a consequence,the induced normal and shear stresses are not modeled appropriately during the flow of the granular phase in the CFB recirculation system.The failure of conventional models,such as that of von Mises/Coulomb,is mainly caused by false approximation of the yield criterion which is not applicable to the CFB recirculation system.The present work adopts an alternative yield function,used for the first time in TFM Eulerian modeling.The proposed model is based on the Pitman-Schaeffer-Gray-Stiles yield criterion.Both the temporal deformation of the solid granular phase and the repose angle that the granular phase forms are more accurately simulated by this model.The numerical results of the proposed model agree well with experimental data,implying that frictional forces are efficiently simulated by the new model.

  6. Experimental investigation and thermodynamic modeling of the Zr-Y system

    Directory of Open Access Journals (Sweden)

    Bu M.J.

    2010-01-01

    Full Text Available Based on the critical review of all the available experimental data in the literature, 8 key alloys were prepared by arc melting to investigate the phase equilibria in the Zr-Y system, These alloys, which were annealed at 5 different temperatures (800°C, 1000°C, 1100°C, 1120°C, 1160°C, were analyzed by means of X-ray diffraction, differential scanning calorimetry, optical microscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy. The results showed that a peritectoid reaction (βZr + (αY = (αZr occurs at 886°C ± 5°C, and an eutectic reaction L = (βZr + (αY occurs at 1313°C ± 5°C. Taking into account the experimental data obtained both from this work and the literature, the Zr-Y system was thermodynamically modeled. The previously reported temperature for the peritectic reaction of (βY + L = (αY at about 1490 °C is supported by our thermodynamic calculation. Comparison between the calculated and measured phase diagrams shows that the thermodynamic calculation can well account for the experimental data.

  7. A hydroponic rice seedling culture model system for investigating proteome of salt stress in rice leaf.

    Science.gov (United States)

    Kim, Dea-Wook; Rakwal, Randeep; Agrawal, Ganesh Kumar; Jung, Young-Ho; Shibato, Junko; Jwa, Nam-Soo; Iwahashi, Yumiko; Iwahashi, Hitoshi; Kim, Du Hyun; Shim, Ie-Sung; Usui, Kenji

    2005-12-01

    By using an in vivo hydroponic rice seedling culture system, we investigated the physiological and biochemical responses of a model rice japonica cultivar Nipponbare to salt stress using proteomics and classical biochemical methods. Yoshida's nutrient solution (YS) was used to grow rice seedlings. YS-grown 18-day-old seedlings manifested highly stable and reproducible symptoms, prominently the wilting and browning of the 3rd leaf, reduced photosynthetic activity, inhibition in overall seedling growth, and failure to develop new (5th) leaf, when subjected to salt stress by transferring them to YS containing 130 mM NaCl for 4 days. As leaf response to salt stress is least investigated in rice by proteomics, we used the 3rd leaf as source material. A comparison of 2-DE protein profiles between the untreated control and salt-stressed 3rd leaves revealed 55 differentially expressed CBB-stained spots, where 47 spots were increased over the control. Of these changed spots, the identity of 33 protein spots (27 increased and 5 decreased) was determined by nESI-LC-MS/MS. Most of these identified proteins belonged to major metabolic processes like photosynthetic carbon dioxide assimilation and photorespiration, suggesting a good correlation between salt stress-responsive proteins and leaf morphology. Moreover, 2-DE immunoblot and enzymatic activity analyses of 3rd leaves revealed remarkable changes in the key marker enzymes associated with oxidative damage to salt stress: ascorbate peroxidase and lipid peroxidation were induced, and catalase was suppressed. These results demonstrate that hydroponic culture system is best suited for proteomics of salt stress in rice seedling.

  8. Novel systems for in vivo monitoring and microenvironmental investigations of diabetic neuropathy in a murine model.

    Science.gov (United States)

    Amit, Sharon; Yaron, Avraham

    2012-11-01

    Peripheral neuropathy is a devastating complication of diabetes conferring vast morbidity and mortality. Despite prolonged efforts to elucidate the mechanisms underlying diabetic related neuropathic phenomena and develop effective therapies, current treatment is for the most part glycemic control and symptomatic care. This is partially due to the intricate pathophysiology of diabetic neuropathy and the scarcity of valid experimental models. The aim of the study was to establish novel systems enabling monitoring and dissection of significant processes in the development of diabetic neuropathy. In a non-invasive in vivo model, two-photon microscopy is applied to evaluate mechanoreceptors (Meissner corpuscles) within an intact footpad of transgenic mice expressing a fluorescent neuronal tracer. By applying this advanced technology, which couples potent tissue penetration with superb resolution, we documented qualitative and quantitative diabetes-specific alterations in these sensory structures. Detection of such changes previously required laborious invasive histopathological techniques. In parallel, we present an ex vivo system that mimics the native microenvironment of the nerve ending via a unique co-culture of primary sensory neurons and thin skin slices. In conjunction with innovative high-throughput digital axonal measurements and computerized quantification tools, this method enables an unbiased exploration of neuronal autonomous and non-autonomous malfunctions. Using this setup we demonstrate that while the diabetic nerve retains a near-normal growth and regeneration capacities, the diabetic skin exhibits a decreased ability to support axonal outgrowth. Thus, an early target organ failure rather than intrinsic neuronal failure may initiate the neuropathy. Overall, the illustrated experimental platforms may greatly facilitate the holistic investigation of diabetic neuropathy.

  9. Investigating spatial differentiation of model parameters in a carbon cycle data assimilation system

    Science.gov (United States)

    Ziehn, T.; Knorr, W.; Scholze, M.

    2011-06-01

    Better estimates of the net exchange of CO2 between the atmosphere and the terrestrial biosphere are urgently needed to improve predictions of future CO2 levels in the atmosphere. The carbon cycle data assimilation system (CCDAS) offers the capability of inversion, while it is at the same time based on a process model that can be used independent of observational data. CCDAS allows the assimilation of atmospheric CO2 concentrations into the terrestrial biosphere model BETHY, constraining its process parameters via an adjoint approach. Here, we investigate the effect of spatial differentiation of a universal carbon balance parameter of BETHY on posterior net CO2 fluxes and their uncertainties. The parameter, β, determines the characteristics of the slowly decomposing soil carbon pool and represents processes that are difficult to model explicitly. Two cases are studied with an assimilation period of 1979 to 2003. In the base case, there is a separate β for each plant functional type (PFT). In the regionalization case, β is differentiated not only by PFT, but also according to each of 11 large continental regions as used by the TransCom project. We find that the choice of spatial differentiation has a profound impact not only on the posterior (optimized) fluxes and their uncertainties, but even more so on the spatial covariance of the uncertainties. Differences are most pronounced in tropical regions, where observations are sparse. While regionalization leads to an improved fit to the observations by about 20% compared to the base case, we notice large spatial variations in the posterior net CO2 flux on a grid cell level. The results illustrate the need for universal process formulations in global-scale atmospheric CO2 inversion studies, at least as long as the observational network is too sparse to resolve spatial fluctuations at the regional scale.

  10. Investigations of the Climate System Response to Climate Engineering in a Hierarchy of Models

    Science.gov (United States)

    McCusker, Kelly E.

    Global warming due to anthropogenic emissions of greenhouse gases is causing negative impacts on diverse ecological and human systems around the globe, and these impacts are projected to worsen as climate continues to warm. In the absence of meaningful greenhouse gas emissions reductions, new strategies have been proposed to engineer the climate, with the aim of preventing further warming and avoiding associated climate impacts. We investigate one such strategy here, falling under the umbrella of `solar radiation management', in which sulfate aerosols are injected into the stratosphere. We use a global climate model with a coupled mixed-layer depth ocean and with a fully-coupled ocean general circulation model to simulate the stabilization of climate by balancing increasing carbon dioxide with increasing stratospheric sulfate concentrations. We evaluate whether or not severe climate impacts, such as melting Arctic sea ice, tropical crop failure, or destabilization of the West Antarctic ice sheet, could be avoided. We find that while tropical climate emergencies might be avoided by use of stratospheric aerosol injections, avoiding polar emergencies cannot be guaranteed due to large residual climate changes in those regions, which are in part due to residual atmospheric circulation anomalies. We also find that the inclusion of a fully-coupled ocean is important for determining the regional climate response because of its dynamical feedbacks. The efficacy of stratospheric sulfate aerosol injections, and solar radiation management more generally, depends on its ability to be maintained indefinitely, without interruption from a variety of possible sources, such as technological failure, a breakdown in global cooperation, lack of funding, or negative unintended consequences. We next consider the scenario in which stratospheric sulfate injections are abruptly terminated after a multi- decadal period of implementation while greenhouse gas emissions have continued unabated

  11. Methodological and musicological investigation of the System & Contrast model for musical form description

    OpenAIRE

    Deruty, Emmanuel; Bimbot, Frédéric; Van Wymeersch, Brigitte

    2013-01-01

    The semiotic description of music structure aims at representing the high-level organization of music pieces in a concise, generic and reproducible way as a low-rate stream of arbitrary symbols from a limited alphabet, which results into a sequence of " semiotic units ". In this context, the purpose of the System & Contrast model is to address the internal organization of the semiotic units. In this report, the System & Contrast model is approached from different angles in relation to varied ...

  12. Zebrafish: an exciting model for investigating the spatio-temporal pattern of enteric nervous system development.

    LENUS (Irish Health Repository)

    Doodnath, Reshma

    2012-02-01

    AIM: Recently, the zebrafish (Danio rerio) has been shown to be an excellent model for human paediatric research. Advantages over other models include its small size, externally visually accessible development and ease of experimental manipulation. The enteric nervous system (ENS) consists of neurons and enteric glia. Glial cells permit cell bodies and processes of neurons to be arranged and maintained in a proper spatial arrangement, and are essential in the maintenance of basic physiological functions of neurons. Glial fibrillary acidic protein (GFAP) is expressed in astrocytes, but also expressed outside of the central nervous system. The aim of this study was to investigate the spatio-temporal pattern of GFAP expression in developing zebrafish ENS from 24 h post-fertilization (hpf), using transgenic fish that express green fluorescent protein (GFP). METHODS: Zebrafish embryos were collected from transgenic GFP Tg(GFAP:GFP)(mi2001) adult zebrafish from 24 to 120 hpf, fixed and processed for whole mount immunohistochemistry. Antibodies to Phox2b were used to identify enteric neurons. Specimens were mounted on slides and imaging was performed using a fluorescent laser confocal microscope. RESULTS: GFAP:GFP labelling outside the spinal cord was identified in embryos from 48 hpf. The patterning was intracellular and consisted of elongated profiles that appeared to migrate away from the spinal cord into the periphery. At 72 and 96 hpf, GFAP:GFP was expressed dorsally and ventrally to the intestinal tract. At 120 hpf, GFAP:GFP was expressed throughout the intestinal wall, and clusters of enteric neurons were identified using Phox2b immunofluorescence along the pathway of GFAP:GFP positive processes, indicative of a migratory pathway of ENS precursors from the spinal cord into the intestine. CONCLUSION: The pattern of migration of GFAP:GFP expressing cells outside the spinal cord suggests an organized, early developing migratory pathway to the ENS. This shows for the

  13. Investigations of a rabbit (Oryctolagus cuniculus model of systemic lupus erythematosus (SLE, BAFF and its receptors.

    Directory of Open Access Journals (Sweden)

    Jiahui Yang

    Full Text Available B-cell activation factor belonging to the tumor necrosis factor family (BAFF is a major contributor to survival of B lymphocytes during development and maturation. A relationship between circulating BAFF levels and disease activity has been reported in patients with the autoimmune disease Systemic Lupus Erythematosus (SLE. Clinical trials targeting BAFF or its receptors are currently in progress. In order to further characterize a rabbit (Oryctolagus cuniculus model of SLE, we investigated the expression of BAFF and its receptors in non-inbred, pedigreed rabbits derived from breeding and selection based on autoantibody responses. We immunized rabbits related to previous groups that developed autoantibodies and inflammatory responses after immunizations with peptides synthesized on multiple antigen-branched polylysine backbones. Blood and sera collected before immunization and after boosts were used for health monitoring, analyses of serum autoantibody responses by ELISA and immunofluorescence. Peripheral blood mononuclear cells (PBMC were studied by flow cytometry and were the source of mRNA for quantitative PCR analyses. We hypothesized that BAFF mRNA expression and serum BAFF levels measured indirectly through BAFF receptor binding might increase in autoantibody-producing rabbits. Immunized rabbits developed elevated levels of leucocyte populations, anti-nuclear, anti-dsDNA and other autoantibodies. BR3 mRNA levels in total PBMC decreased and BAFF levels remained low and unchanged in most immunized rabbits. By flow cytometry, percentages of BAFF positive cells decreased. Percentages of transmembrane activator and CAML interactor (TACI decreased in most rabbits from all the immunized groups. The rabbit is an important model for human autoimmune and infectious diseases, and a high quality draft rabbit genome assembly was recently completed. Human disease models developed in non-inbred pedigreed animals are better able to reflect the complexities

  14. Investigation and Modelling of Thermal Conditions in Low Flow SDHW Systems

    DEFF Research Database (Denmark)

    Shah, Louise Jivan

    1999-01-01

    The purpose of this study was to characterise the thermal conditions in low flow SDHW systems. As the heat storage has proved to be the most important system component, there has been an emphasis on this component in the study. A literature survey revealed that the mantle tank heat storage type...... and compared with the CFD-predicted flow structures in the mantle. The results showed that the mantle flow was highly dominated by buoyancy and the CFD-models were able to model this flow. With a steel mantle tank, different dynamic thermal experiments were carried out in a heat storage test facility...

  15. An Investigation of Employees' Use of E-Learning Systems: Applying the Technology Acceptance Model

    Science.gov (United States)

    Lee, Yi-Hsuan; Hsieh, Yi-Chuan; Chen, Yen-Hsun

    2013-01-01

    The purpose of this study is to apply the technology acceptance model to examine the employees' attitudes and acceptance of electronic learning (e-learning) systems in organisations. This study examines four factors (organisational support, computer self-efficacy, prior experience and task equivocality) that are believed to influence employees'…

  16. Investigation of Control Model in a New Series Hybrid Hydraulic/Electric System for Heavy Vehicles Based on Energy Efficiency

    Directory of Open Access Journals (Sweden)

    Soroosh Mahmoodi

    2016-01-01

    Full Text Available An interesting model which was able to recuperate and reuse braking energy was investigated. It was named series hybrid hydraulic/electric system (SHHES. The innovated model was presented for heavy hybrid vehicles to overcome the existing drawbacks of single energy storage sources. The novelty of this paper was investigation of a new series hybrid vehicle with triple sources, combustion engine, electric motor, and hydraulic sources. It was simulated with MATLAB-Simulink and different operational mode of control system was investigated. The aim was to improve the efficiency of the energy-loading components in the power train system and the transmission system independently. The ability to store and reuse the kinetic energy was added to the system to prevent energy wasting while the vehicle was braking. Control models were also investigated to realize suitable control algorithms to offer the best efficiency in system components for different vehicle conditions. The torque control strategy based on fuzzy logic controller was proposed to achieve better vehicle performance while the fuel consumption was minimized. The results implied efficient storage and usage in the transmission system. A small vehicle model experimentally verified the simulation results.

  17. Computational Investigation of a Boundary-Layer Ingestion Propulsion System for the Common Research Model

    Science.gov (United States)

    Blumenthal, Brennan

    2016-01-01

    This thesis will examine potential propulsive and aerodynamic benefits of integrating a boundary-layer ingestion (BLI) propulsion system with a typical commercial aircraft using the Common Research Model geometry and the NASA Tetrahedral Unstructured Software System (TetrUSS). The Numerical Propulsion System Simulation (NPSS) environment will be used to generate engine conditions for CFD analysis. Improvements to the BLI geometry will be made using the Constrained Direct Iterative Surface Curvature (CDISC) design method. Previous studies have shown reductions of up to 25% in terms of propulsive power required for cruise for other axisymmetric geometries using the BLI concept. An analysis of engine power requirements, drag, and lift coefficients using the baseline and BLI geometries coupled with the NPSS model are shown. Potential benefits of the BLI system relating to cruise propulsive power are quantified using a power balance method and a comparison to the baseline case is made. Iterations of the BLI geometric design are shown and any improvements between subsequent BLI designs presented. Simulations are conducted for a cruise flight condition of Mach 0.85 at an altitude of 38,500 feet and an angle of attack of 2deg for all geometries. A comparison between available wind tunnel data, previous computational results, and the original CRM model is presented for model verification purposes along with full results for BLI power savings. Results indicate a 14.3% reduction in engine power requirements at cruise for the BLI configuration over the baseline geometry. Minor shaping of the aft portion of the fuselage using CDISC has been shown to increase the benefit from boundary-layer ingestion further, resulting in a 15.6% reduction in power requirements for cruise as well as a drag reduction of eighteen counts over the baseline geometry.

  18. Computational Investigation of a Boundary-Layer Ingesting Propulsion System for the Common Research Model

    Science.gov (United States)

    Blumenthal, Brennan T.; Elmiligui, Alaa; Geiselhart, Karl A.; Campbell, Richard L.; Maughmer, Mark D.; Schmitz, Sven

    2016-01-01

    The present paper examines potential propulsive and aerodynamic benefits of integrating a Boundary-Layer Ingestion (BLI) propulsion system into a typical commercial aircraft using the Common Research Model (CRM) geometry and the NASA Tetrahedral Unstructured Software System (TetrUSS). The Numerical Propulsion System Simulation (NPSS) environment is used to generate engine conditions for CFD analysis. Improvements to the BLI geometry are made using the Constrained Direct Iterative Surface Curvature (CDISC) design method. Previous studies have shown reductions of up to 25% in terms of propulsive power required for cruise for other axisymmetric geometries using the BLI concept. An analysis of engine power requirements, drag, and lift coefficients using the baseline and BLI geometries coupled with the NPSS model are shown. Potential benefits of the BLI system relating to cruise propulsive power are quantified using a power balance method, and a comparison to the baseline case is made. Iterations of the BLI geometric design are shown and any improvements between subsequent BLI designs presented. Simulations are conducted for a cruise flight condition of Mach 0.85 at an altitude of 38,500 feet and an angle of attack of 2 deg for all geometries. A comparison between available wind tunnel data, previous computational results, and the original CRM model is presented for model verification purposes along with full results for BLI power savings. Results indicate a 14.4% reduction in engine power requirements at cruise for the BLI configuration over the baseline geometry. Minor shaping of the aft portion of the fuselage using CDISC has been shown to increase the benefit from Boundary-Layer Ingestion further, resulting in a 15.6% reduction in power requirements for cruise as well as a drag reduction of eighteen counts over the baseline geometry.

  19. Investigations of solar combi systems

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    2005-01-01

    investigations are carried out for different solar combi system types by means of the simulation program Trnsys (Klein et al., 1996) and the multiport store model (Drück, 2000) with input to the models determined by the experiments. The work is carried out within the Solar Heating and Cooling Programme...

  20. A systems-based mathematical modelling framework for investigating the effect of drugs on solid tumours

    Directory of Open Access Journals (Sweden)

    Liu Cong

    2011-12-01

    Full Text Available Abstract Background Elucidating the effects of drugs on solid tumours is a highly challenging multi-level problem, since this involves many complexities associated with transport and cellular response, which in turn is characterized by highly non-linear chemical signal transduction. Appropriate systems frameworks are needed to seriously address the sources of these complexities, especially from the cellular side. Results We develop a skeletal modelling framework incorporating interstitial drug transport, intracellular signal processing and cell population descriptions. The descriptions aim to appropriately capture the nature of information flow. The model is deliberately formulated to start with simple intracellular descriptions so that additional features can be incorporated in a modular fashion. Two kinds of intracellular signalling modules which describe the drug effect were considered, one a monostable switch and the other a bistable switch. Analysis of our model revealed how different drug stimuli can lead to cell killing in the tumour. Interestingly both modules considered exhibited similar trends. The effects of important parameters were also studied. Conclusions We have created a predictive systems platform integrating drug transport and cellular response which can be systematically augmented to include additional layers of cellular complexity. Our results indicate that intracellular signalling models which are qualitatively different can give rise to similar behaviour to simple (and typical stimuli, and that validating intracellular descriptions must be performed with care by considering a variety of drug stimuli.

  1. The LARsen Ice Shelf System, Antarctica, LARISSA a Model for Antarctic Integrated System Science (AISS) Investigations using Marine Platforms

    Science.gov (United States)

    Domack, E. W.; Huber, B. A.; Vernet, M.; Leventer, A.; Scambos, T. A.; Mosley-Thompson, E. S.; Smith, C. R.; de Batist, M. A.; Yoon, H.; Larissa

    2010-12-01

    The LARISSA program is the first interdisciplinary project funded in the AISS program of the NSF Office of Polar Programs and was officially launched in the closing days of the IPY. This program brings together investigators, students, and media to address the rapid and fundamental changes taking place in the region of the Larsen Ice Shelf and surrounding areas. Scientific foci include: glaciologic and oceanographic interactions, the response of pelagic and benthic ecosystems to ice shelf decay, sedimentary record of ice shelf break disintegration, the geologic evolution of ice shelf systems over the last 100,000 years, paleoclimate/environmental records from marine sediment and ice cores, and the crustal response to ice mass loss at decade to millennial time scales. The first major field season took place this past austral summer aboard the NB Palmer (cruise NBP10-01) which deployed with a multi-layered logistical infrastructure that included: two Bell 220 aircraft, a multifunctional deep water ROV, video guided sediment corer, jumbo piston core, and an array of oceanographic and biological sensors and instruments. In tandem with this ship based operation Twin Otter aircraft supported an ice core team upon the crest of the Bruce Plateau with logistic support provided by the BAS at Rothera Station. Although unusually heavy sea ice prevented much of the original work from being completed in the Larsen Embayment the interdisciplinary approach proved useful. Further the logistical model of ship based aircraft to support interdisciplinary work proved viable, again despite an unusually severe summer meterologic pattern across the northern Antarctic Peninsula. As the program moves forward other vessels will come into play and the model can be applied to interdisciplinary objectives in other regions of Antarctica which are remote and lack land based infrastructure to support coastal field programs in glaciology, geology, or meteorology. This work could then be completed

  2. [Amphibians as a model system for the investigation of respiratory control development].

    Science.gov (United States)

    Belzile, Olivier; Simard, Edith; Gulemetova, Roumiana; Bairam, Aida; Kinkead, Richard

    2004-10-01

    Recent medical advances have made it possible for babies to survive premature birth at increasingly earlier developmental stages. This population requires costly and sophisticated medical care to address the problems associated with immaturity of the respiratory system. In addition to pulmonary complications, respiratory instability and apnea reflecting immaturity of the respiratory control system are major causes of hospitalization and morbidity in this highly vulnerable population. These medical concerns, combined with the curiosity of physiologists, have contributed to the expansion of research in respiratory neurobiology. While most researchers working in this field commonly use rodents as an animal model, recent research using in vitro brainstem preparation from bullfrogs (Rana catesbeiana) have revealed the technical advantages of this animal model, and shown that the basic principles underlying respiratory control and its ontogeny are very similar between these two groups of vertebrates. The present review highlights the recent advances in the area of research with a focus on intermittent (episodic) breathing and the role of serotonergic and GABAergic modulation of respiratory activity during development.

  3. Modeling and simulation of induction motor drive system to investigate and mitigate of PWM inverter' s adverse effects

    Institute of Scientific and Technical Information of China (English)

    ESMAELI Abdolreza; SUN Li

    2007-01-01

    Modeling and simulation of induction motor drive system to investigate and mitigate the adverse effects of PWM inverter based on analysis, modeling and simulation are presented. The estimation of conducted disturbances and other adverse effects of PWM inverter by simulation offer a considerable gain from the economic point of view. For an accurate model of the motor drive system including mains, rectifier, inverter, motor and its long cables, the high frequency parasitic current paths are taken into account. The novel model and its parasitic values for three-phase induction motor system are presented. Finally a new solution for suppressing EMI, common mode voltage, leakage current, bearing current and shaft voltages is proposed and the results show the excellent performances of proposed solution including active and passive filters.

  4. Modeling Acequia Irrigation Systems Using System Dynamics: Model Development, Evaluation, and Sensitivity Analyses to Investigate Effects of Socio-Economic and Biophysical Feedbacks

    Directory of Open Access Journals (Sweden)

    Benjamin L. Turner

    2016-10-01

    Full Text Available Agriculture-based irrigation communities of northern New Mexico have survived for centuries despite the arid environment in which they reside. These irrigation communities are threatened by regional population growth, urbanization, a changing demographic profile, economic development, climate change, and other factors. Within this context, we investigated the extent to which community resource management practices centering on shared resources (e.g., water for agricultural in the floodplains and grazing resources in the uplands and mutualism (i.e., shared responsibility of local residents to maintaining traditional irrigation policies and upholding cultural and spiritual observances embedded within the community structure influence acequia function. We used a system dynamics modeling approach as an interdisciplinary platform to integrate these systems, specifically the relationship between community structure and resource management. In this paper we describe the background and context of acequia communities in northern New Mexico and the challenges they face. We formulate a Dynamic Hypothesis capturing the endogenous feedbacks driving acequia community vitality. Development of the model centered on major stock-and-flow components, including linkages for hydrology, ecology, community, and economics. Calibration metrics were used for model evaluation, including statistical correlation of observed and predicted values and Theil inequality statistics. Results indicated that the model reproduced trends exhibited by the observed system. Sensitivity analyses of socio-cultural processes identified absentee decisions, cumulative income effect on time in agriculture, and land use preference due to time allocation, community demographic effect, effect of employment on participation, and farm size effect as key determinants of system behavior and response. Sensitivity analyses of biophysical parameters revealed that several key parameters (e.g., acres per

  5. An investigation of a professional development model in science education: A systems approach

    Science.gov (United States)

    Bell, Glenda Love

    The Mathematics and Science Cooperative (MSEC), a four year longevity model of professional development education for in-service teachers, is closely aligned with the spirit and tenets of science for all. This partnership of a university, a school district, and a higher education coordinating board, seeks to promote and improve science and mathematics achievement for underserved and underrepresented populations. This study sought to explore how this model affects elementary in-service teachers' feelings of self-efficacy toward science and science teaching. Interactive Qualitative Research (IQR), a systems approach of natural inquiry, was used for this study. Theory is grounded in the data collected and analyzed through group processes. A core group of teachers, key teachers representing grades one through six and lead teachers the campus contact representatives, received professional development education from university professors in semi-monthly after school workshops and in a three week summer science institute held on-site. In this study, (N = 18) key and lead teachers participated in a focus group, a picture board exercise (a projective type exercise), interviews, and classroom observations. Within the system of the MSEC professional development model, cause and effect relationships among eleven phenomena were identified which had the greatest impact on the teachers' feelings of self-efficacy and science teaching practices. Changed teaching practices were indicated by inquiry-based science lessons with students as active learners. Five principles of self-efficacy: (1) efficacy; (2) goals setting; (3) values; (4) expectancy; and, (5) control beliefs were used to evaluate efficacy beliefs. Findings from the data collection and analysis identified two phenomena, the university instructional leadership role and teacher time commitments and time constraints, both internally and externally imposed, which seemed to have the greatest impact on elementary teachers

  6. Investigations of solar combi systems

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    2005-01-01

    ). However, it is still too early to draw conclusions on the design of solar combi systems. Among others, the following questions needs to be answered: Is an external domestic hot water preparation more desirable than an internal domestic hot water preparation? Is a stratification manifold always more...... desirable than a fixed inlet position? This paper presents experimental investigations of an advanced solar combi system with thermal stratification manifold inlets both in the solar collector loop and in the space heating system and with an external domestic hot water preparation. Theoretical...... investigations are carried out for different solar combi system types by means of the simulation program Trnsys (Klein et al., 1996) and the multiport store model (Drück, 2000) with input to the models determined by the experiments. The work is carried out within the Solar Heating and Cooling Programme...

  7. The Ti-Mn system revisited: experimental investigation and thermodynamic modelling.

    Science.gov (United States)

    Khan, A U; Brož, P; Premović, M; Pavlů, J; Vřeštál, J; Yan, X; Maccio, D; Saccone, A; Giester, G; Rogl, P

    2016-08-17

    As the Ti-Mn phase diagram is part of numerous ternary and higher order systems of technological importance, the present paper defines phase relations which have been experimentally established throughout this work from 800 °C to the melting range based on Differential Thermal Analyses (DTA), X-ray powder diffraction, metallography and Electron Probe Micro Analysis (EPMA) techniques on ∼50 alloys, which were prepared by arc melting or high frequency melting under high purity argon starting from freshly cleaned metal ingots. Novel compounds were identified and reaction isotherms were redefined accordingly. In the Ti-rich region a novel compound TiMn was detected, sandwiched between the known phases: TiMn1-x (∼45 at% Mn) and TiMn1+x (∼55 at% Mn). In the Mn-rich region the hitherto unknown crystal structure of TiMn∼3 was solved from X-ray single crystal diffraction data and found to be of a unique structure type Ti6(Ti1-xMnx)6Mn25 (x = 0.462; space group Pbam (#55); a = 0.79081(3) nm, b = 2.58557(9) nm, c = 0.47931(2) nm), which consists of two consecutive layers of the hexagonal MgZn2-type Laves phase (TiMn2) and a combined layer of alternate structure blocks of MgZn2 type and Zr4Al3 type. Whereas TiMn can be considered as a line compound (solubility range phase: Ti8(TixMn1-x)6Mn39, 80 to 84 at% Ti). Supported by ab initio calculations of the ground state energy for the Laves phase, the new experimental results enabled thermodynamic modelling of the entire Ti-Mn phase diagram providing a complete and novel set of thermodynamic data thus providing a sound basis for future thermodynamic predictions of higher order Ti-Mn-X-Y systems.

  8. Controls on the Archean climate system investigated with a global climate model.

    Science.gov (United States)

    Wolf, E T; Toon, O B

    2014-03-01

    The most obvious means of resolving the faint young Sun paradox is to invoke large quantities of greenhouse gases, namely, CO2 and CH4. However, numerous changes to the Archean climate system have been suggested that may have yielded additional warming, thus easing the required greenhouse gas burden. Here, we use a three-dimensional climate model to examine some of the factors that controlled Archean climate. We examine changes to Earth's rotation rate, surface albedo, cloud properties, and total atmospheric pressure following proposals from the recent literature. While the effects of increased planetary rotation rate on surface temperature are insignificant, plausible changes to the surface albedo, cloud droplet number concentrations, and atmospheric nitrogen inventory may each impart global mean warming of 3-7 K. While none of these changes present a singular solution to the faint young Sun paradox, a combination can have a large impact on climate. Global mean surface temperatures at or above 288 K could easily have been maintained throughout the entirety of the Archean if plausible changes to clouds, surface albedo, and nitrogen content occurred.

  9. Investigating heavy-metal hyperaccumulation using Thlaspi caerulescens as a model system.

    Science.gov (United States)

    Milner, Matthew J; Kochian, Leon V

    2008-07-01

    Metal-hyperaccumulating plant species are plants that are endemic to metalliferous soils and are able to tolerate and accumulate metals in their above-ground tissues to very high concentrations. One such hyperaccumulator, Thlaspi caerulescens, has been widely studied for its remarkable properties to tolerate toxic levels of zinc (Zn), cadmium (Cd) and sometimes nickel (Ni) in the soil, and accumulate these metals to very high levels in the shoot. The increased awareness regarding metal-hyperaccumulating plants by the plant biology community has helped spur interest in the possible use of plants to remove heavy metals from contaminated soils, a process known as phytoremediation. Hence, there has been a focus on understanding the mechanisms that metal-hyperaccumulator plant species such as Thlaspi caerulescens employ to absorb, detoxify and store metals in order to use this information to develop plants better suited for the phytoremediation of metal-contaminated soils. In this review, an overview of the findings from recent research aimed at better understanding the physiological mechanisms of Thlaspi caerulescens heavy-metal hyperaccumulation as well as the underlying molecular and genetic determinants for this trait will be discussed. Progress has been made in understanding some of the fundamental Zn and Cd transport physiology in T. caerulescens. Furthermore, some interesting metal-related genes have been identified and characterized in this plant species, and regulation of the expression of some of these genes may be important for hyperaccumulation. Thlaspi caerulescens is a fascinating and useful model system not only for studying metal hyperaccumulation, but also for better understanding micronutrient homeostasis and nutrition. Considerable future research is still needed to elucidate the molecular, genetic and physiological bases for the extreme metal tolerance and hyperaccumulation exhibited by plant species such as T. caerulescens.

  10. Investigation and Development of Data-Driven D-Region Model for HF Systems Impacts

    Science.gov (United States)

    Eccles, J. V.; Rice, D.; Sojka, J. J.; Hunsucker, R. D.

    2002-01-01

    Space Environment Corporation (SEC) and RP Consultants (RPC) are to develop and validate a weather-capable D region model for making High Frequency (HF) absorption predictions in support of the HF communications and radar communities. The weather-capable model will assimilate solar and earth space observations from NASA satellites. The model will account for solar-induced impacts on HF absorption, including X-rays, Solar Proton Events (SPE's), and auroral precipitation. The work plan includes: I . Optimize D-region model to quickly obtain ion and electron densities for proper HF absorption calculations. 2. Develop indices-driven modules for D-region ionization sources for low, mid, & high latitudes including X-rays, cosmic rays, auroral precipitation, & solar protons. (Note: solar spectrum & auroral modules already exist). 3. Setup low-cost monitors of existing HF beacons and add one single-frequency beacon. 4. Use PENEX HF-link database with HF monitor data to validate D-region/HF absorption model using climatological ionization drivers. 5. Develop algorithms to assimilate NASA satellite data of solar, interplanetary, and auroral observations into ionization source modules. 6. Use PENEX HF-link & HF-beacon data for skill score comparison of assimilation versus climatological D-region/HF absorption model. Only some satellites are available for the PENEX time period, thus, HF-beacon data is necessary. 7. Use HF beacon monitors to develop HF-link data assimilation algorithms for regional improvement to the D-region/HF absorption model.

  11. Investigating transportation system in container terminals and developing a yard crane scheduling model

    Directory of Open Access Journals (Sweden)

    Hassan Javanshir

    2012-01-01

    Full Text Available The world trade has tremendous growth in marine transportation. This paper studies yard crane scheduling problem between different blocks in container terminal. Its purpose is to minimize total travel time of cranes between blocks and total delayed workload in blocks at different periods. In this way the problem is formulated as a mixed integer programming (MIP model. The block pairs between which yard cranes will be transferred, during the various periods, is determined by this model. Afterwards the model is coded in LINGO software, which benefits from branch and bound algorithm to solve. Computational results determine the yard cranes movement sequence among blocks to achieve minimum total travel time for cranes and minimum total delayed workload in blocks at different planning periods. Also the results show capability and adequacy of the developed model.

  12. Investigation of the interaction between modified ISCOMs and stratum corneum lipid model systems

    DEFF Research Database (Denmark)

    Madsen, Henriette Baun; Arboe-Andersen, Helle M.; Rozlosnik, Noemi;

    2010-01-01

    Transfer (FRET), Atomic Force Microscopy (AFM), Electrochemical Impedance Spectroscopy (EIS) and cryo-Transmission Electron Microscopy (cryo-TEM) it was shown that application of nanoparticles to the SCL bilayers results in lipid disturbance. Investigation of this interaction by means of Isothermal...

  13. Investigation Into The Model Of The Vehicle System For Speed Support

    Directory of Open Access Journals (Sweden)

    Jurij Grigorovič

    2013-12-01

    Full Text Available The paper presents a rectilinear motion of a car modelled applyingsoftware package “Matlab/Simulink“ where two vehicles aremoving simultaneously one after the other. The parameters ofeach vehicle have been identified separately assessing a driver,road and environment.

  14. Fundamental Investigation of the Microstructural Parameters to Improve Dynamic Response in Al-Cu Model System

    Science.gov (United States)

    2014-05-01

    the- art high-strain-rate testing techniques such as Kolsky (split Hopkinson) pressure bar in combination with well calibrated, high-speed, high...HKL Nordlys detector and Aztec EBSD acquisition system. Analysis of the EBSD data was completed with the Oxford HKL Channel 5 software suite. EBSD

  15. Experimental investigation of weir instability in main vessel cooling system of 1/4 FBR model

    Energy Technology Data Exchange (ETDEWEB)

    Thirumalai, M., E-mail: mtl@igcar.gov.i [Fast Reactor Technology Group, Department of Atomic Energy, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu (India); Anandaraj, M.; Kumar, P. Anup [Fast Reactor Technology Group, Department of Atomic Energy, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu (India); Prakash, V., E-mail: prakash@igcar.gov.i [Fast Reactor Technology Group, Department of Atomic Energy, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu (India); Anandbabu, C.; Kalyanasundaram, P.; Vaidyanathan, G. [Fast Reactor Technology Group, Department of Atomic Energy, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu (India)

    2010-01-15

    The 500 MWe Prototype Fast Breeder Reactor (PFBR) is under construction at Kalpakkam, India. The main vessel of this pool type reactor acts as the primary containment in the reactor assembly. In order to keep the main vessel temperature below creep range and to reduce high temperature embrittlement and also to ensure its healthiness for 40 years of reactor life, a small fraction of core flow (0.5 m{sup 3}/s) is sent through an annular space formed between the main vessel and a cylindrical baffle (primary thermal baffle) to cool the vessel. The sodium after cooling the main vessel overflows the primary baffle (weir shell) and falls into another concentric pool of sodium separated from the cold pool by the secondary thermal baffle and then returned to cold pool. The weir shell, where the overflow of liquid sodium takes place, is a thin shell prone to flow induced vibrations due to instability caused by sloshing and fluid-structure interaction. A similar vibration phenomenon was first observed during the commissioning of Super-Phenix reactor. In order to understand the phenomenon and provide necessary experimental back up to validate the analytical models, weir instability experiments were conducted in a 1:4 scale stainless steel (SS) model installed in a water loop. The experiments were conducted with flow rate and fall height as the varying parameters. The experimental results showed that the instability of the weir shell was caused due to fluid structure interaction. This paper discusses the details of the model, the modeling laws, similitude criteria adopted, analytical prediction, the experimental results and conclusion.

  16. Investigation of heat induced reactions between lipid oxidation products and amino acids in lipid rich model systems and hazelnuts.

    Science.gov (United States)

    Karademir, Yeşim; Göncüoğlu, Neslihan; Gökmen, Vural

    2013-07-01

    This study aimed to investigate the contribution of lipid oxidation to non-enzymatic browning reactions in lipid rich model and actual food systems. Hazelnut oil and model reaction mixtures consisting of different amino acids were heated under certain conditions to determine possible lipid oxidation and non-enzymatic browning reaction products. In model systems, the Schiff base of 2,4-decadienal, its decarboxylated form, and reaction products formed after hydrolytic cleavage of the Schiff base or decarboxylated form were identified by high resolution mass spectrometry. No furosine was detected in hazelnuts after roasting at 160 °C while the concentration of free amino acids significantly decreased. 2,4-Decadienal reacted effectively with all amino acids studied through a Maillard type carbonyl-amine condensation pathway. (2E,4E)-Deca-2,4-dien-1-amine was identified as a typical reaction product in model systems and roasted hazelnuts. In lipid-rich foods like hazelnuts, lipid-derived carbonyls might be responsible for potential modifications of free and protein bound amino acids during heating.

  17. Thermal imaging of microfluidic systems as a model for investigating energy efficiency

    Science.gov (United States)

    Mauk, Michael G.; Chiou, Richard Y.; Varapula, Dharma T.; Kamarajugadda, Pranav R.; Liu, Changchun; Tseng, Tzu-Liang (.

    2015-05-01

    We explore the use of a commercial thermal imaging infrared camera (7-12 micron, uncooled microbolometer array, 320 x 240 resolution) to characterize microfluidic devices with the aims of: 1) evaluating the usefulness of thermal imaging to assess various flow configurations with respect to heat transfer, and 2) developing educational laboratory projects combining rapid prototyping, thermal imaging, microfluidics, and heat transfer. We investigated concurrent and countercurrent heat exchangers, mixing streams of different temperature (cold and hot water), mixing streams yielding a heat of mixing (ethanol and water), mixing streams yielding a heat of reaction (acid-base neutralization), and freezing and heating flowing streams in channels with a Peltier module. Energy efficiency can be assessed to determine the feasibility and effectiveness of microfluidic designs. Substantial improvements in mixing and heat transfer using a magnetic stirrer are demonstrated with thermal imaging.

  18. Cachaça distillation investigated on the basis of model systems

    Directory of Open Access Journals (Sweden)

    H. F. A. Scanavini

    2012-06-01

    Full Text Available This work reports experimental tests using commercial spirits that were diluted and had their initial composition modified in order to better measure the distillation behavior of selected minor compounds of importance for the quality of alcoholic beverages. Such compounds were added to the commercial cachaça and the corresponding model wine, obtained after the spirits' dilution, was distilled. In this way a more precise distillation profile could be determined for those minor compounds. The alembic heating was performed by electrical resistance and the corresponding heat transfer coefficient was determined by analyzing the thermal behavior of the still during the distillations. A simulation algorithm was developed, including the mass and enthalpy balances as well as the heat transfer flux to the boiling wine. Good agreement between experimental and simulated results was obtained for the distillate rate, alcoholic graduation, temperature and most minor component profiles.

  19. Advantages of using the CRISPR/Cas9 system of genome editing to investigate male reproductive mechanisms using mouse models

    Directory of Open Access Journals (Sweden)

    Samantha A. M. Young

    2015-01-01

    Full Text Available Gene disruption technology has long been beneficial for the study of male reproductive biology. However, because of the time and cost involved, this technology was not a viable method except in specialist laboratories. The advent of the CRISPR/Cas9 system of gene disruption has ushered in a new era of genetic investigation. Now, it is possible to generate gene-disrupted mouse models in very little time and at very little cost. This Highlight article discusses the application of this technology to study the genetics of male fertility and looks at some of the future uses of this system that could be used to reveal the essential and nonessential genetic components of male reproductive mechanisms.

  20. Investigating IT Faculty Resistance to Learning Management System Adoption Using Latent Variables in an Acceptance Technology Model.

    Science.gov (United States)

    Bousbahi, Fatiha; Alrazgan, Muna Saleh

    2015-01-01

    To enhance instruction in higher education, many universities in the Middle East have chosen to introduce learning management systems (LMS) to their institutions. However, this new educational technology is not being used at its full potential and faces resistance from faculty members. To investigate this phenomenon, we conducted an empirical research study to uncover factors influencing faculty members' acceptance of LMS. Thus, in the Fall semester of 2014, Information Technology faculty members were surveyed to better understand their perceptions of the incorporation of LMS into their courses. The results showed that personal factors such as motivation, load anxiety, and organizational support play important roles in the perception of the usefulness of LMS among IT faculty members. These findings suggest adding these constructs in order to extend the Technology acceptance model (TAM) for LMS acceptance, which can help stakeholders of the university to implement the use of this system. This may assist in planning and evaluating the use of e-learning.

  1. Investigating Surface Bias Errors in the Weather Research and Forecasting (WRF) Model using a Geographic Information System (GIS)

    Science.gov (United States)

    2015-02-01

    horizontal grid spacing inner domain centered near San Diego, California. The San Diego area contains a mixture of urban , suburban, agricultural, and...Global Forecast System (GFS) model (Environmental Modeling Center 2003). The WRE–N is envisioned to be a rapid-update cycling application of WRF–ARW...surface– hydrology model with the Penn State-NCAR MM5 modeling system. Part I: Model implementation and sensitivity. Monthly Weather Review. 2001a

  2. A Mock Circulatory System Incorporating a Compliant 3D-Printed Anatomical Model to Investigate Pulmonary Hemodynamics.

    Science.gov (United States)

    Knoops, Paul G M; Biglino, Giovanni; Hughes, Alun D; Parker, Kim H; Xu, Linzhang; Schievano, Silvia; Torii, Ryo

    2017-07-01

    A realistic mock circulatory system (MCS) could be a valuable in vitro testbed to study human circulatory hemodynamics. The objective of this study was to design a MCS replicating the pulmonary arterial circulation, incorporating an anatomically representative arterial model suitable for testing clinically relevant scenarios. A second objective of the study was to ensure the system's compatibility with magnetic resonance imaging (MRI) for additional measurements. A latex pulmonary arterial model with two generations of bifurcations was manufactured starting from a 3D-printed mold reconstructed from patient data. The model was incorporated into a MCS for in vitro hydrodynamic measurements. The setup was tested under physiological pulsatile flow conditions and results were evaluated using wave intensity analysis (WIA) to investigate waves traveling in the arterial system. Increased pulmonary vascular resistance (IPVR) was simulated as an example of one pathological scenario. Flow split between right and left pulmonary artery was found to be realistic (54 and 46%, respectively). No substantial difference in pressure waveform was observed throughout the various generations of bifurcations. Based on WIA, three main waves were identified in the main pulmonary artery (MPA), that is, forward compression wave, backward compression wave, and forward expansion wave. For IPVR, a rise in mean pressure was recorded in the MPA, within the clinical range of pulmonary arterial hypertension. The feasibility of using the MCS in the MRI scanner was demonstrated with the MCS running 2 h consecutively while acquiring preliminary MRI data. This study shows the development and verification of a pulmonary MCS, including an anatomically correct, compliant latex phantom. The setup can be useful to explore a wide range of hemodynamic questions, including the development of patient- and pathology-specific models, considering the ease and low cost of producing rapid prototyping molds, and the

  3. Investigations on the effect of antioxidant type and concentration and model system matrix on acrylamide formation in model Maillard reaction systems.

    Science.gov (United States)

    Constantinou, Costas; Koutsidis, Georgios

    2016-04-15

    The formation of acrylamide in model Maillard reaction systems containing phenolic compounds was examined, with regards to phenolic type, concentration, and model system matrix. In dry glyoxal/asparagine waxy maize starch (WMS) systems, 9 out of 10 examined phenolics demonstrated an inhibiting effect, with the most significant reductions (55-60%) observed for caffeoylquinic acids. In WMS glucose/asparagine systems, examination of three different concentrations (0.1, 0.5 and 1 μmol/g WMS) suggested a 'minimum effective concentration' for epicatechin and caffeic acid, whilst addition of caffeoylquinic acids resulted in dose-dependent acrylamide reduction (25-75%). The discordant results of further studies utilising different matrices (dry and wet-to-dry) indicated that, apart from the nature and chemical reactivity, the matrix and the physical state of the reactants might be important for acrylamide formation.

  4. Software Engineering Support of the Third Round of Scientific Grand Challenge Investigations: Earth System Modeling Software Framework Survey

    Science.gov (United States)

    Talbot, Bryan; Zhou, Shu-Jia; Higgins, Glenn; Zukor, Dorothy (Technical Monitor)

    2002-01-01

    One of the most significant challenges in large-scale climate modeling, as well as in high-performance computing in other scientific fields, is that of effectively integrating many software models from multiple contributors. A software framework facilitates the integration task, both in the development and runtime stages of the simulation. Effective software frameworks reduce the programming burden for the investigators, freeing them to focus more on the science and less on the parallel communication implementation. while maintaining high performance across numerous supercomputer and workstation architectures. This document surveys numerous software frameworks for potential use in Earth science modeling. Several frameworks are evaluated in depth, including Parallel Object-Oriented Methods and Applications (POOMA), Cactus (from (he relativistic physics community), Overture, Goddard Earth Modeling System (GEMS), the National Center for Atmospheric Research Flux Coupler, and UCLA/UCB Distributed Data Broker (DDB). Frameworks evaluated in less detail include ROOT, Parallel Application Workspace (PAWS), and Advanced Large-Scale Integrated Computational Environment (ALICE). A host of other frameworks and related tools are referenced in this context. The frameworks are evaluated individually and also compared with each other.

  5. Electrokinetic investigations on the system polystyrene/aqueous electrolyte solution : verification of model theories on dilute and concentrated dispersions

    NARCIS (Netherlands)

    Put, van der A.G.

    1980-01-01

    This thesis presents a systematic experimental and theoretical study on electrokinetic and electroconducting properties of disperse systems. The increasing interest in transport processes through charged porous systems has recently brought about a corresponding growth of models and theories since re

  6. Disruption of Saccharomyces cerevisiae by Plantaricin 149 and investigation of its mechanism of action with biomembrane model systems.

    Science.gov (United States)

    Lopes, José Luiz S; Nobre, Thatyane M; Siano, Alvaro; Humpola, Verónica; Bossolan, Nelma R S; Zaniquelli, Maria E D; Tonarelli, Georgina; Beltramini, Leila M

    2009-10-01

    The action of a synthetic antimicrobial peptide analog of Plantaricin 149 (Pln149a) against Saccharomyces cerevisiae and its interaction with biomembrane model systems were investigated. Pln149a was shown to inhibit S. cerevisiae growth by more than 80% in YPD medium, causing morphological changes in the yeast wall and remaining active and resistant to the yeast proteases even after 24 h of incubation. Different membrane model systems and carbohydrates were employed to better describe the Pln149a interaction with cellular components using circular dichroism and fluorescence spectroscopies, adsorption kinetics and surface elasticity in Langmuir monolayers. These assays showed that Pln149a does not interact with either mono/polysaccharides or zwitterionic LUVs, but is strongly adsorbed to and incorporated into negatively charged surfaces, causing a conformational change in its secondary structure from random-coil to helix upon adsorption. From the concurrent analysis of Pln149a adsorption kinetics and dilatational surface elasticity data, we determined that 2.5 muM is the critical concentration at which Pln149a will disrupt a negative DPPG monolayer. Furthermore, Pln149a exhibited a carpet-like mechanism of action, in which the peptide initially binds to the membrane, covering its surface and acquiring a helical structure that remains associated to the negatively charged phospholipids. After this electrostatic interaction, another peptide region causes a strain in the membrane, promoting its disruption.

  7. Modelling the impact of causal and non-causal factors on disruption duration for Toronto's subway system: An exploratory investigation using hazard modelling.

    Science.gov (United States)

    Louie, Jacob; Shalaby, Amer; Habib, Khandker Nurul

    2017-01-01

    Most investigations of incident-related delay duration in the transportation context are restricted to highway traffic, with little attention given to delays due to transit service disruptions. Studies of transit-based delay duration are also considerably less comprehensive than their highway counterparts with respect to examining the effects of non-causal variables on the delay duration. However, delays due to incidents in public transit service can have serious consequences on the overall urban transportation system due to the pivotal and vital role of public transit. The ability to predict the durations of various types of transit system incidents is indispensable for better management and mitigation of service disruptions. This paper presents a detailed investigation on incident delay durations in Toronto's subway system over the year 2013, focusing on the effects of the incidents' location and time, the train-type involved, and the non-adherence to proper recovery procedures. Accelerated Failure Time (AFT) hazard models are estimated to investigate the relationship between these factors and the resulting delay duration. The empirical investigation reveals that incident types that impact both safety and operations simultaneously generally have longer expected delays than incident types that impact either safety or operations alone. Incidents at interchange stations are cleared faster than incidents at non-interchange stations. Incidents during peak periods have nearly the same delay durations as off-peak incidents. The estimated models are believed to be useful tools in predicting the relative magnitude of incident delay duration for better management of subway operations.

  8. Investigating IT Faculty Resistance to Learning Management System Adoption Using Latent Variables in an Acceptance Technology Model

    Directory of Open Access Journals (Sweden)

    Fatiha Bousbahi

    2015-01-01

    Full Text Available To enhance instruction in higher education, many universities in the Middle East have chosen to introduce learning management systems (LMS to their institutions. However, this new educational technology is not being used at its full potential and faces resistance from faculty members. To investigate this phenomenon, we conducted an empirical research study to uncover factors influencing faculty members’ acceptance of LMS. Thus, in the Fall semester of 2014, Information Technology faculty members were surveyed to better understand their perceptions of the incorporation of LMS into their courses. The results showed that personal factors such as motivation, load anxiety, and organizational support play important roles in the perception of the usefulness of LMS among IT faculty members. These findings suggest adding these constructs in order to extend the Technology acceptance model (TAM for LMS acceptance, which can help stakeholders of the university to implement the use of this system. This may assist in planning and evaluating the use of e-learning.

  9. Quantitative investigations of aggregate systems.

    Science.gov (United States)

    Rai, D K; Beaucage, G; Jonah, E O; Britton, D T; Sukumaran, S; Chopra, S; Gonfa, G Goro; Härting, M

    2012-07-28

    Nanomaterials with disordered, ramified structure are increasingly being used for applications where low cost and enhanced performance are desired. A particular example is the use in printed electronics of inorganic conducting and semiconducting nanoparticles. The electrical, as well as other physical properties depend on the arrangement and connectivity of the particles in such aggregate systems. Quantification of aggregate structure and development of structure/property relationships is difficult and progress in the application of these materials in electronics has mainly been empirical. In this paper, a scaling model is used to parameterize the structure of printed electronic layers. This model has chiefly been applied to polymers but surprisingly it shows applicability to these nanolayers. Disordered structures of silicon nanoparticles forming aggregates are investigated using small angle x-ray scattering coupled with the scaling model. It is expected that predictions using these structural parameters can be made for electrical properties. The approach may have wide use in understanding and designing nano-aggregates for electronic devices.

  10. Investigating patient safety culture across a health system: multilevel modelling of differences associated with service types and staff demographics

    National Research Council Canada - National Science Library

    Gallego, Blanca; Westbrook, Mary T; Dunn, Adam G; Braithwaite, Jeffrey

    2012-01-01

    To use multilevel modelling to compare the patient safety cultures of types of services across a health system and to determine whether differences found can be accounted for by staffs' professions...

  11. Investigation of Noise in Electronic Ultrasonic Systems

    Directory of Open Access Journals (Sweden)

    Paulius Adomavičius

    2011-03-01

    Full Text Available Noise models in ultrasonic control system have been investigated. Ultrasonic system channel consist of exciting generator, ultrasonic transducer, amplitude limiter, amplifier, low band filter and A/D converter. The ultrasonic transducers have been described as Von Hippel model, Van Dyke model or improved Van Dyke model. Advantages and disadvantages of these models are discussed in this paper. Noise models of amplitude limiter and linear operational amplifier are presented. The summary results of calculated noise spectral density of ultrasonic system channel have been presented.Article in Lithuanian

  12. Impact of artificial recharge and drought in Tafilalet Oasis system: First investigation by GIS and groundwater modeling

    Science.gov (United States)

    Bouaamlat, I.; Larabi, A.; Faouzi, M.

    2013-12-01

    The geographical location of Tafilalet oasis system (TOS) in the south of the valley of Ziz (Morocco) offers him a particular advantage on the plane of water potential. The surface water which comes from humid regions of the High Atlas and intercepted by a dam then converged through the watercourse of Ziz towards the plain of the TOS, have created the conditions for the formation of a water table relatively rich with regard to the local climatic conditions (arid climate with recurrent drought). Because of this situation, the region has one of the largest palms of North Africa. Thus there is an agricultural activity that is practiced in a 21 irrigation areas whose size rarely exceeds 2,000 hectare. Given the role of the water table in the economic development of the region, a hydrogeological study was conducted to understand the impact of artificial recharge and recurrent droughts on the development of the groundwater reserves of TOS. In this study, a three-dimensional model of groundwater flow was developed for the Tafilalet oasis system aquifer, to assist the decision makers as a "management tool" in order to assess alternative schemes for development and exploitation of groundwater resources based on the variation of artificial recharge and drought, using for the first time the Modflow code. This study takes into account the most possible real hydrogeological conditions and using the geographical information system (GIS) for the organisation and treatment of data and applying a multidisciplinary approach combining geostatistical and hydrogeological modeling. The results from this numerical investigation of the TOS aquifer shows that the commissioning of the dam to control the flows of extreme flood and good management of water releases, has avoided the losses of irrigation water and consequently the non-overexploitation of the groundwater. So that with one or two water releases per year from the dam of flow rate more than 14 million m3/year it is possible to

  13. 3D stratigraphic modeling of the Congo turbidite system since 210 ka: an investigation of factors controlling sedimentation

    Science.gov (United States)

    Laurent, Dimitri; Picot, Marie; Marsset, Tania; Droz, Laurence; Rabineau, Marina; Granjeon, Didier; Molliex, Stéphane

    2017-04-01

    The geometry and internal functioning of turbidite systems are relatively well-constrained today. However, the respective role of autogenic (topographic compensation, dynamics of turbidity currents…) and allogenic factors (tectonics, sea-level, climate) governing their architectural evolution is still under debate. The geometry of the Quaternary Congo Fan is characterized by successive sedimentary prograding/retrograding cycles bounded by upfan avulsions, reflecting a periodic control of sedimentation (Picot et al., 2016). Multi-proxy studies revealed a strong interplay between autogenic control and climate forcing as evidenced by changes in fluvial sediment supplies consistent with arid and humid periods in the Congo River Basin. In the light of these results, the aim of this study is to investigate the relative impact of internal and external forcing factors controlling, both in time and space, the formation and evolution of depocenters of the Congo Deep-Sea Fan since 210 ka. This work represents the first attempt to model in 3D the stratigraphic architecture of the Congo turbidite system using DionisosFlow (IFP-EN), a diffusion process-based software. It allows the simulation of sediment transport and the 3D geometry reproduction of sedimentary units based on physical processes such as sea level changes, tectonics, sediment supply and transport. According to the modeling results, the role of topographic compensation in the deep-sea fan geometry is secondary compared to climate changes in the drainage basin. It appears that a periodic variation of sediment discharge and water flow is necessary to simulate the timing and volume of prograding/retrograding sedimentary cycles and more particularly the upfan avulsion events. The best-fit simulations show that the overriding factor for such changes corresponds to the expansion of the vegetation cover in the catchment basin associated to the Milankovitch cycle of precession which controlled the West African Monsoon

  14. Sf9 cells: a versatile model system to investigate the pharmacological properties of G protein-coupled receptors.

    Science.gov (United States)

    Schneider, Erich H; Seifert, Roland

    2010-12-01

    The Sf9 cell/baculovirus expression system is widely used for high-level protein expression, often with the purpose of purification. However, proteins may also be functionally expressed in the defined Sf9 cell environment. According to the literature, the pharmacology of G-protein-coupled receptors (GPCRs) functionally reconstituted in Sf9 cells is similar to the receptor properties in mammalian cells. Sf9 cells express both recombinant GPCRs and G-proteins at much higher levels than mammalian cells. Sf9 cells can be grown in suspension culture, providing an inexpensive way of obtaining large protein amounts. Co-infection with various baculoviruses allows free combination of GPCRs with different G-proteins. The absence of constitutively active receptors in Sf9 cells provides an excellent signal-to background ratio in functional assays, allowing the detection of agonist-independent receptor activity and of small ligand-induced signals including partial agonistic and inverse agonistic effects. Insect cell Gα(i)-like proteins mostly do not couple productively to mammalian GPCRs. Thus, unlike in mammalian cells, Sf9 cells do not require pertussis toxin treatment to obtain a Gα(i)-free environment. Co-expression of GPCRs with Gα(i1), Gα(i2), Gα(i3) or Gα(o) in Sf9 cells allows the generation of a selectivity profile for these Gα(i/o)-isoforms. Additionally, GPCR-G-protein combinations can be compared with defined 1:1 stoichiometry by expressing GPCR-Gα fusion proteins. Sf9 cells can also be employed for ligand screening in medicinal chemistry programs, using radioligand binding assays or functional assays, like the steady-state GTPase- or [(35)S]GTPγS binding assay. This review shows that Sf9 cells are a versatile model system to investigate the pharmacological properties of GPCRs.

  15. Investigation of the stability of hemiclonal population systems of water frogs hybridogeneous complex by the means of simulation modeling

    Directory of Open Access Journals (Sweden)

    M. O. Kravchenko

    2011-01-01

    Full Text Available The concept of stability used in ecology and mathematics is analyzed. Stability is interpreted as the ability of the system to remain in a restricted zone of a phase space that corresponds to a certain type of systems. This approach is applied to describe changes in the structure of hemiclonal population systems of hybridogenous complex of water frogs (Pelophylax esculentus complex. Simulation model of these population systems built on a recursive difference equations in MS Excel is used. The dynamics of transitions in the part of phase space of the hemiclonal populationsystems of water frogs is described. Typology of stabile states of biosystems is analyzed.

  16. The Role of Model and Initial Condition Error in Numerical Weather Forecasting Investigated with an Observing System Simulation Experiment

    Science.gov (United States)

    Prive, Nikki C.; Errico, Ronald M.

    2013-01-01

    A series of experiments that explore the roles of model and initial condition error in numerical weather prediction are performed using an observing system simulation experiment (OSSE) framework developed at the National Aeronautics and Space Administration Global Modeling and Assimilation Office (NASA/GMAO). The use of an OSSE allows the analysis and forecast errors to be explicitly calculated, and different hypothetical observing networks can be tested with ease. In these experiments, both a full global OSSE framework and an 'identical twin' OSSE setup are utilized to compare the behavior of the data assimilation system and evolution of forecast skill with and without model error. The initial condition error is manipulated by varying the distribution and quality of the observing network and the magnitude of observation errors. The results show that model error has a strong impact on both the quality of the analysis field and the evolution of forecast skill, including both systematic and unsystematic model error components. With a realistic observing network, the analysis state retains a significant quantity of error due to systematic model error. If errors of the analysis state are minimized, model error acts to rapidly degrade forecast skill during the first 24-48 hours of forward integration. In the presence of model error, the impact of observation errors on forecast skill is small, but in the absence of model error, observation errors cause a substantial degradation of the skill of medium range forecasts.

  17. Investigating the links of internal and external reliability with the system conditionality in Gauss-Markov models with uncorrelated observations

    Science.gov (United States)

    Prószyński, Witold

    2013-12-01

    The relationship between internal response-based reliability and conditionality is investigated for Gauss-Markov (GM) models with uncorrelated observations. The models with design matrices of full rank and of incomplete rank are taken into consideration. The formulas based on the Singular Value Decomposition (SVD) of the design matrix are derived which clearly indicate that the investigated concepts are independent of each other. The methods are presented of constructing for a given design matrix the matrices equivalent with respect to internal response-based reliability as well as the matrices equivalent with respect to conditionality. To analyze conditionality of GM models, in general being inconsistent systems, a substitute for condition number commonly used in numerical linear algebra is developed, called a pseudo-condition^number. Also on the basis of the SVD a formula for external reliability is proposed, being the 2-norm of a vector of parameter distortions induced by minimal detectable error in a particular observation. For systems with equal nonzero singular values of the design matrix, the formula can be expressed in terms of the index of internal response-based reliability and the pseudo-condition^number. With these measures appearing in explicit form, the formula shows, although only for the above specific systems, the character of the impact of internal response-based reliability and conditionality of the model upon its external reliability. Proofs for complementary properties concerning the pseudo-condition^number and the 2-norm of parameter distortions in systems with minimal constraints are given in the Appendices. Numerical examples are provided to illustrate the theory. Badany jest związek między niezawodnością wewnętrzną bazującą na odpowiedziach modelu a uwarunkowaniem układu dla modeli Gaussa-Markova z obserwacjami nieskorelowanymi. Rozpatrywane są przy tym modele z macierzami projektu pełnego i niepełnego rzędu. Wzory wyprowadzone

  18. Computer Profiling Based Model for Investigation

    Directory of Open Access Journals (Sweden)

    Neeraj Choudhary

    2011-10-01

    Full Text Available Computer profiling is used for computer forensic analysis, and proposes and elaborates on a novel model for use in computer profiling, the computer profiling object model. The computer profiling object model is an information model which models a computer as objects with various attributes and inter-relationships. These together provide the information necessary for a human investigator or an automated reasoning engine to make judgments as to the probable usage and evidentiary value of a computer system. The computer profiling object model can be implemented so as to support automated analysis to provide an investigator with the informationneeded to decide whether manual analysis is required.

  19. Advanced Wastewater Treatment Engineering—Investigating Membrane Fouling in both Rotational and Static Membrane Bioreactor Systems Using Empirical Modelling

    Directory of Open Access Journals (Sweden)

    Parneet Paul

    2016-01-01

    Full Text Available Advanced wastewater treatment using membranes are popular environmental system processes since they allow reuse and recycling. However, fouling is a key limiting factor and so proprietary systems such as Avanti’s RPU-185 Flexidisks membrane bioreactor (MBR use novel rotating membranes to assist in ameliorating it. In earlier research, this rotating process was studied by creating a simulation model based on first principles and traditional fouling mechanisms. In order to directly compare the potential benefits of this rotational system, this follow-up study was carried out using Avanti’s newly developed static (non-rotating Flexidisks MBR system. The results from operating the static pilot unit were simulated and modelled using the rotational fouling model developed earlier however with rotational switching functions turned off and rotational parameters set to a static mode. The study concluded that a rotating MBR system could increase flux throughput when compared against a similar static system. It is thought that although the slowly rotating spindle induces a weak crossflow shear, it is still able to even out cake build up across the membrane surface, thus reducing the likelihood of localised critical flux being exceeded at the micro level and lessening the potential of rapid trans-membrane pressure increases at the macro level.

  20. Advanced Wastewater Treatment Engineering-Investigating Membrane Fouling in both Rotational and Static Membrane Bioreactor Systems Using Empirical Modelling.

    Science.gov (United States)

    Paul, Parneet; Jones, Franck Anderson

    2016-01-05

    Advanced wastewater treatment using membranes are popular environmental system processes since they allow reuse and recycling. However, fouling is a key limiting factor and so proprietary systems such as Avanti's RPU-185 Flexidisks membrane bioreactor (MBR) use novel rotating membranes to assist in ameliorating it. In earlier research, this rotating process was studied by creating a simulation model based on first principles and traditional fouling mechanisms. In order to directly compare the potential benefits of this rotational system, this follow-up study was carried out using Avanti's newly developed static (non-rotating) Flexidisks MBR system. The results from operating the static pilot unit were simulated and modelled using the rotational fouling model developed earlier however with rotational switching functions turned off and rotational parameters set to a static mode. The study concluded that a rotating MBR system could increase flux throughput when compared against a similar static system. It is thought that although the slowly rotating spindle induces a weak crossflow shear, it is still able to even out cake build up across the membrane surface, thus reducing the likelihood of localised critical flux being exceeded at the micro level and lessening the potential of rapid trans-membrane pressure increases at the macro level.

  1. An Investigation of Employees' Use of E-Learning Systems: Applying the Technology Acceptance Model

    Science.gov (United States)

    Lee, Yi-Hsuan; Hsieh, Yi-Chuan; Chen, Yen-Hsun

    2013-01-01

    The purpose of this study is to apply the technology acceptance model to examine the employees' attitudes and acceptance of electronic learning (e-learning) systems in organisations. This study examines four factors (organisational support, computer self-efficacy, prior experience and task equivocality) that are believed to influence…

  2. Investigating IT Faculty Resistance to Learning Management System Adoption Using Latent Variables in an Acceptance Technology Model

    OpenAIRE

    Fatiha Bousbahi; Muna Saleh Alrazgan

    2015-01-01

    To enhance instruction in higher education, many universities in the Middle East have chosen to introduce learning management systems (LMS) to their institutions. However, this new educational technology is not being used at its full potential and faces resistance from faculty members. To investigate this phenomenon, we conducted an empirical research study to uncover factors influencing faculty members’ acceptance of LMS. Thus, in the Fall semester of 2014, Information Technology faculty mem...

  3. Investigation of present teaching performance assessment system problems and preposition of an appropriate model by technology: Sciences classrooms

    Directory of Open Access Journals (Sweden)

    Mostafa Ghaderi

    2014-12-01

    Full Text Available The common assessment method is manager assess teachers during teaching process, recruiting students’ opinions or roll call which is classified in traditional assessment methods. In this study, besides detection of present system problems, recruiting of video data as a new method is investigated to obtain a teacher performance assessment in classroom which is scientific and attributable. Finally, video data as a new way to evaluate teacher’s performance was identified as a suitable method. We argue that using of video data as a new method for evaluating the performance of teachers in the classroom in order to achieve the objectives of the performance assessment system and the current system problems was helpful.

  4. An aggregate model of grid-connected, large-scale, offshore wind farm for power stability investigations-importance of windmill mechanical system

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Knudsen, H.

    2002-01-01

    An aggregate model of a large-scale offshore wind farm, comprising 72 wind turbines of 2 MW rating each, is set up. Representation of the shaft systems of the wind turbines shall be taken into account when a simplified aggregate model of the wind farm is used in voltage stability investigations. ...... and the entire network. All these phenomena are different compared to previous experiences with modelling of conventional power plants with synchronous generators and stiff shaft systems.......An aggregate model of a large-scale offshore wind farm, comprising 72 wind turbines of 2 MW rating each, is set up. Representation of the shaft systems of the wind turbines shall be taken into account when a simplified aggregate model of the wind farm is used in voltage stability investigations....... Because the shaft system gives a soft coupling between the rotating wind turbine and the induction generator, the large-scale wind farm cannot always be reduced to one-machine equivalent and use of multi-machine equivalents will be necessary for reaching accuracy of the investigation results...

  5. Modeling and investigation of refrigeration system performance with two-phase fluid injection in a scroll compressor

    Science.gov (United States)

    Gu, Rui

    Vapor compression cycles are widely used in heating, refrigerating and air-conditioning. A slight performance improvement in the components of a vapor compression cycle, such as the compressor, can play a significant role in saving energy use. However, the complexity and cost of these improvements can block their application in the market. Modifying the conventional cycle configuration can offer a less complex and less costly alternative approach. Economizing is a common modification for improving the performance of the refrigeration cycle, resulting in decreasing the work required to compress the gas per unit mass. Traditionally, economizing requires multi-stage compressors, the cost of which has restrained the scope for practical implementation. Compressors with injection ports, which can be used to inject economized refrigerant during the compression process, introduce new possibilities for economization with less cost. This work focuses on computationally investigating a refrigeration system performance with two-phase fluid injection, developing a better understanding of the impact of injected refrigerant quality on refrigeration system performance as well as evaluating the potential COP improvement that injection provides based on refrigeration system performance provided by Copeland.

  6. Hydrogeological investigation of an oasis-system aquifer in arid southeastern Morocco by development of a groundwater flow model

    Science.gov (United States)

    Bouaamlat, Ilias; Larabi, Abdelkader; Faouzi, Mohamed

    2016-09-01

    Groundwater of the Tafilalet oasis system (TOS) is an important water resource in the lower Ziz and Rheris valleys of arid southeastern Morocco. The unconfined aquifer is exploited for domestic consumption and irrigation. A groundwater flow model was developed to assess the impact of climatic variations and development, including the construction of hydraulic structures, on the hydrodynamic behavior of the aquifer. Numerical simulations were performed by implementing a spatial database within a geographic information system and using the Arc Hydro Groundwater tool with the code MODFLOW-2000. The results of steady-state and transient simulations between 1960 and 2011 show that the water table is at equilibrium between recharge, which is mainly by surface-water infiltration, and discharge by evapotranspiration. After the commissioning of the Hassan Addakhil dam in 1971, hydraulic heads became more sensitive to annual variations than to seasonal variations. Heads are also influenced by recurrent droughts and the highest water-level changes are recorded in irrigated areas. The model provides a way of managing groundwater resources in the TOS. It can be used as a tool to predict the impact of different management plans for the protection of groundwater against overexploitation and deterioration of water quality.

  7. In vitro model systems to investigate bile salt export pump (BSEP) activity and drug interactions: A review.

    Science.gov (United States)

    Cheng, Yaofeng; Woolf, Thomas F; Gan, Jinping; He, Kan

    2016-08-05

    The bile salt export pump protein (BSEP), expressed on the canalicular membranes of hepatocytes, is primarily responsible for the biliary excretion of bile salts. The inhibition of BSEP transport activity can lead to an increase in intracellular bile salt levels and liver injury. This review discusses the various in vitro assays currently available for assessing the effect of drugs or other chemical entities to modulate BSEP transport activity. BSEP transporter assays use one of the following platforms: Xenopus laevis oocytes; canalicular membrane vesicles (CMV); BSEP-expressed membrane vesicles; cell lines expressing BSEP; sandwich cultured hepatocytes (SCH); and hepatocytes in suspension. Two of these, BSEP-expressed insect membrane vesicles and sandwich cultured hepatocytes, are the most commonly used assays. BSEP membrane vesicles prepared from transfected insect cells are useful for assessing BSEP inhibition or substrate specificity and exploring mechanisms of BSEP-associated genetic diseases. This model can be applied in a high-throughput format for discovery-drug screening. However, experimental results from use of membrane vesicles may lack physiological relevance and the model does not allow for investigation of in situ metabolism in modulation of BSEP activity. Hepatocyte-based assays that use the SCH format provide results that are generally more physiologically relevant than membrane assays. The SCH model is useful in detailed studies of the biliary excretion of drugs and BSEP inhibition, but due to the complexity of SCH preparation, this model is used primarily for determining biliary clearance and BSEP inhibition in a limited number of compounds. The newly developed hepatocyte in suspension assay avoids many of the complexities of the SCH method. The use of pooled cryopreserved hepatocytes in suspension minimizes genetic variance and individual differences in BSEP activity and also provides the opportunity for higher throughput screening and cross

  8. Investigation of Higher Brain Functions in Music Composition Using Models of the Cortex Based on Physical System Analogies.

    Science.gov (United States)

    Leng, Xiaodan

    The trion model was developed using the Mountcastle organizational principle for the column as the basic neuronal network in the cortex and the physical system analogy of Fisher's ANNNI spin model. An essential feature is that it is highly structured in time and in spatial connections. Simulations of a network of trions have shown that large numbers of quasi-stable, periodic spatial-temporal firing patterns can be excited. Characteristics of these patterns include the quality of being readily enhanced by only a small change in connection strengths, and that the patterns evolve in certain natural sequences from one to another. With only somewhat different parameters than used for studying memory and pattern recognition, much more flowing and intriguing patterns emerged from the simulations. The results were striking when these probabilistic evolutions were mapped onto pitches and instruments to produce music: For example different simple mappings of the same evolution give music having the "flavor" of a minuet, a waltz, folk music, or styles of specific periods. A theme can be learned so that evolutions have this theme and its variations reoccurring more often. That the trion model is a viable model for the coding of musical structure in human composition and perception is suggested. It is further proposed that model is relevant for examining creativity in the higher cognitive functions of mathematics and chess, which are similar to music. An even higher level of cortical organization was modeled by coupling together several trion networks. Further, one of the crucial features of higher brain function, especially in music composition or appreciation, is the role of emotion and mood as controlled by the many neuromodulators or neuropeptides. The MILA model whose underlying basis is zero-level representation of Kac-Moody algebra is used to modulate periodically the firing threshold of each network. Our preliminary results show that the introduction of "neuromodulation

  9. Investigation for improving Global Positioning System (GPS) orbits using a discrete sequential estimator and stochastic models of selected physical processes

    Science.gov (United States)

    Goad, Clyde C.; Chadwell, C. David

    1993-01-01

    GEODYNII is a conventional batch least-squares differential corrector computer program with deterministic models of the physical environment. Conventional algorithms were used to process differenced phase and pseudorange data to determine eight-day Global Positioning system (GPS) orbits with several meter accuracy. However, random physical processes drive the errors whose magnitudes prevent improving the GPS orbit accuracy. To improve the orbit accuracy, these random processes should be modeled stochastically. The conventional batch least-squares algorithm cannot accommodate stochastic models, only a stochastic estimation algorithm is suitable, such as a sequential filter/smoother. Also, GEODYNII cannot currently model the correlation among data values. Differenced pseudorange, and especially differenced phase, are precise data types that can be used to improve the GPS orbit precision. To overcome these limitations and improve the accuracy of GPS orbits computed using GEODYNII, we proposed to develop a sequential stochastic filter/smoother processor by using GEODYNII as a type of trajectory preprocessor. Our proposed processor is now completed. It contains a correlated double difference range processing capability, first order Gauss Markov models for the solar radiation pressure scale coefficient and y-bias acceleration, and a random walk model for the tropospheric refraction correction. The development approach was to interface the standard GEODYNII output files (measurement partials and variationals) with software modules containing the stochastic estimator, the stochastic models, and a double differenced phase range processing routine. Thus, no modifications to the original GEODYNII software were required. A schematic of the development is shown. The observational data are edited in the preprocessor and the data are passed to GEODYNII as one of its standard data types. A reference orbit is determined using GEODYNII as a batch least-squares processor and the

  10. Modeling tools for an Integrated River-Delta-Sea system investigation: the Pan-European Research Infrastructure DANUBIUS-RI philosophy

    Science.gov (United States)

    Umgiesser, Georg; Bellafiore, Debora; De Pascalis, Francesca; Icke, Joost; Stanica, Adrian

    2017-04-01

    The DANUBIUS Research Infrastructure (DANUBIUS-RI) is a new initiative to address the challenges and opportunities of research on large river- sea (RS) systems. DANUBIUS-RI is a distributed pan-European RI that will provide a platform for interdisciplinary research. It will deal with RS investigation through facilities and expertise from a large number of European institutions becoming a 'one-stop shop' for knowledge exchange in managing RS systems, ranging from freshwater to marine research. Globally, RS systems are complex and dynamic, with huge environmental, social and economic value. They are poorly understood but under increasing pressure through pollution, hydraulic engineering, water supply, energy, flood control and erosion. RS systems in Europe are among the most impacted globally, after centuries of industrialisation, urbanisation and agricultural intensification. Improved understanding is essential to avoid irreversible degradation and for restoration. DANUBIUS-RI will provide, among a number of other facilities concerning observations, analyses, impacts' evaluation, a modeling node that will provide integrated up-to-date tools, at locations of high scientific importance and opportunity, covering the RS systems - from source (upper parts of rivers - mountain lakes) to the transition with coastal seas. Modeling will be one of the major services provided by DANUBIUS-RI, relying on the inputs from the whole RI. RS systems are challenging from a modelling point of view, because of the complex morphology and the wide temporal and spatial range of processes occurring. Scale interaction plays a central role, considering the different hydro-eco-morphological processes on the large (basin) and small (local, coast, rivers, lagoons) scale. Currently, different model applications are made for the different geographical domains, and also for subsets of the processes. For instance there are separate models for rainfall runoff in the catchment, a sewer model for the

  11. The Investigation of TLC Model Checker Properties

    Directory of Open Access Journals (Sweden)

    Vadym Viktorovych Shkarupylo

    2016-06-01

    Full Text Available This paper presents the investigation and comparison of TLC model checking method (TLA Checker properties. There are two different approaches to method usage which are considered. The first one consists of a transition system states attendance by breadth-first search (BFS, and the second one by depth-first search (DFS. The Kripke structure has been chosen as a transition system model. A case study has been conducted, where composite web service usage scenario has been considered. Obtained experimental results are aimed at increasing the effectiveness of TLA+ specifications automated verification.

  12. Applying Machine Trust Models to Forensic Investigations

    Science.gov (United States)

    Wojcik, Marika; Venter, Hein; Eloff, Jan; Olivier, Martin

    Digital forensics involves the identification, preservation, analysis and presentation of electronic evidence for use in legal proceedings. In the presence of contradictory evidence, forensic investigators need a means to determine which evidence can be trusted. This is particularly true in a trust model environment where computerised agents may make trust-based decisions that influence interactions within the system. This paper focuses on the analysis of evidence in trust-based environments and the determination of the degree to which evidence can be trusted. The trust model proposed in this work may be implemented in a tool for conducting trust-based forensic investigations. The model takes into account the trust environment and parameters that influence interactions in a computer network being investigated. Also, it allows for crimes to be reenacted to create more substantial evidentiary proof.

  13. Investigating fire emissions and smoke transport during the Summer of 2013 using an operational smoke modeling system and chemical transport model

    Science.gov (United States)

    ONeill, S. M.; Chung, S. H.; Wiedinmyer, C.; Larkin, N. K.; Martinez, M. E.; Solomon, R. C.; Rorig, M.

    2014-12-01

    Emissions from fires in the Western US are substantial and can impact air quality and regional climate. Many methods exist that estimate the particulate and gaseous emissions from fires, including those run operationally for use with chemical forecast models. The US Forest Service Smartfire2/BlueSky modeling framework uses satellite data and reported information about fire perimeters to estimate emissions of pollutants to the atmosphere. The emission estimates are used as inputs to dispersion models, such as HYSPLIT, and chemical transport models, such as CMAQ and WRF-Chem, to assess the chemical and physical impacts of fires on the atmosphere. Here we investigate the use of Smartfire2/BlueSky and WRF-Chem to simulate emissions from the 2013 fire summer fire season, with special focus on the Rim Fire in northern California. The 2013 Rim Fire ignited on August 17 and eventually burned more than 250,000 total acres before being contained on October 24. Large smoke plumes and pyro-convection events were observed. In this study, the Smartfire2/BlueSky operational emission estimates are compared to other estimation methods, such as the Fire INventory from NCAR (FINN) and other global databases to quantify variations in emission estimation methods for this wildfire event. The impact of the emissions on downwind chemical composition is investigated with the coupled meteorology-chemistry WRF-Chem model. The inclusion of aerosol-cloud and aerosol-radiation interactions in the model framework enables the evaluation of the downwind impacts of the fire plume. The emissions and modeled chemistry can also be evaluated with data collected from the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) aircraft field campaign, which intersected the fire plume.

  14. Mathematical modeling of microbially induced crown corrosion in wastewater collection systems and laboratory investigation and modeling of sulfuric acid corrosion of concrete

    Science.gov (United States)

    Jahani, Fereidoun

    In the model for microbially induced crown corrosion, the diffusion of sulfide inside the concrete pores, its biological conversion to sulfuric acid, and the corrosion of calcium carbonate aggregates are represented. The corrosion front is modeled as a moving boundary. The location of the interface between the corrosion layer and the concrete is determined as part of the solution to the model equations. This model consisted of a system of one dimensional reaction-diffusion equations coupled to an equation describing the movement of the corrosion front. The equations were solved numerically using finite element Galerkin approximation. The concentration profiles of sulfide in the air and the liquid phases, the pH as a function of concrete depth, and the position of the corrosion front. A new equation for the corrosion rate was also derived. A more specific model for the degradation of a concrete specimen exposed to a sulfuric acid solution was also studied. In this model, diffusion of hydrogen ions and their reaction with alkaline components of concrete were expressed using Fick's Law of diffusion. The model equations described the moving boundary, the dissolution rate of alkaline components in the concrete, volume increase of sulfuric acid solution over the concrete specimen, and the boundary conditions on the surface of the concrete. An apparatus was designed and experiments were performed to measure pH changes on the surface of concrete. The data were used to calculate the dissolution rate of the concrete and, with the model, to determine the diffusion rate of sulfuric acid in the corrosion layer and corrosion layer thickness. Electrochemical Impedance Spectroscopy (EIS) was used to study the corrosion rate of iron pins embedded in the concrete sample. The open circuit potential (OCP) determined the onset of corrosion on the surface of the pins. Visual observation of the corrosion layer thickness was in good agreement with the simulation results.

  15. Lipid digestion of protein stabilized emulsions investigated in a dynamic in vitro gastro-intestinal model system

    NARCIS (Netherlands)

    Helbig, A.; Silletti, E.; Aken, G.A. van; Oosterveld, A.; Minekus, M.; Hamer, R.J.; Gruppen, H.

    2013-01-01

    This study investigated the effect of gastric passage of protein stabilized emulsions, i.e., whey protein isolate (WPI) and lysozyme, under dynamic in vitro conditions on both the gastric and intestinal lipolysis. Emulsions were prepared at neutral pH to enable an opposite surface charge. Experiment

  16. Lipid Digestion of Protein Stabilized Emulsions Investigated in a Dynamic In Vitro Gastro-Intestinal Model System

    NARCIS (Netherlands)

    Helbig, A.; Silletti, E.; Aken, van G.A.; Oosterveld, A.; Minekus, M.; Hamer, R.J.; Gruppen, H.

    2013-01-01

    This study investigated the effect of gastric passage of protein stabilized emulsions, i.e., whey protein isolate (WPI) and lysozyme, under dynamic in vitro conditions on both the gastric and intestinal lipolysis. Emulsions were prepared at neutral pH to enable an opposite surface charge. Experiment

  17. Model Systems

    Directory of Open Access Journals (Sweden)

    Francisco Rodríguez-Trelles

    1998-12-01

    Full Text Available Current efforts to study the biological effects of global change have focused on ecological responses, particularly shifts in species ranges. Mostly ignored are microevolutionary changes. Genetic changes may be at least as important as ecological ones in determining species' responses. In addition, such changes may be a sensitive indicator of global changes that will provide different information than that provided by range shifts. We discuss potential candidate systems to use in such monitoring programs. Studies of Drosophila subobscura suggest that its chromosomal inversion polymorphisms are responding to global warming. Drosophila inversion polymorphisms can be useful indicators of the effects of climate change on populations and ecosystems. Other species also hold the potential to become important indicators of global change. Such studies might significantly influence ecosystem conservation policies and research priorities.

  18. THE MODEL OF LAW ENFORCEMENT FOR JUVENILE DELINQUENT IN THE PROCESS OF INVESTIGATION BASED ON LAW NUMBER 11 YEAR 2012 CONCERNING JUVENILE JUSTICE SYSTEM

    Directory of Open Access Journals (Sweden)

    Hamidah Abdurrachman

    2016-01-01

    Full Text Available This study analyses the application of law enforcement model on juvenille offender before the law. Especially, in investigations according to Act number 11, 2012 about Juvenille Penal Court system in Central Java. Since the act has been formally implemented, the penal court elements have been given two years time to prepare strategies in handling juvenille offender through Diversion with Restorative Justice approach. However, the implementation of Diversion needs several infrastructures such as Juvenille Investigators, Diversion Standard of Operation (SOP, and a proper place for investigating children and mediation process, including children cells. This is an empirical study with primary and secondary sources, including analysis of Acts, literature review, and expert review. The data analysis will be done qualitatively.

  19. Modeling and investigation of heavy oxide and alkali-halide scintillators for potential use in neutron and gamma detection systems

    OpenAIRE

    Cadiente, Jeremy S.

    2015-01-01

    Approved for public release; distribution is unlimited Heavy inorganic oxide and alkali-halide crystals, which previous experimental research has indicated to have fast neutron detection efficiencies well over 40%, were investigated for potential use as highly efficient gamma-neutron radiation detectors. The Monte Carlo N-Particle radiation transport code (MCNP) was used to characterize the radiation interactions in a candidate set of crystals, including Bismuth Germanate (BGO), Lead Tungs...

  20. Establishment of fruit bat cells (Rousettus aegyptiacus as a model system for the investigation of filoviral infection.

    Directory of Open Access Journals (Sweden)

    Verena Krähling

    Full Text Available BACKGROUND: The fruit bat species Rousettus aegyptiacus was identified as a potential reservoir for the highly pathogenic filovirus Marburg virus. To establish a basis for a molecular understanding of the biology of filoviruses in the reservoir host, we have adapted a set of molecular tools for investigation of filovirus replication in a recently developed cell line, R06E, derived from the species Rousettus aegyptiacus. METHODOLOGY/PRINCIPAL FINDINGS: Upon infection with Ebola or Marburg viruses, R06E cells produced viral titers comparable to VeroE6 cells, as shown by TCID(50 analysis. Electron microscopic analysis of infected cells revealed morphological signs of filovirus infection as described for human- and monkey-derived cell lines. Using R06E cells, we detected an unusually high amount of intracellular viral proteins, which correlated with the accumulation of high numbers of filoviral nucleocapsids in the cytoplasm. We established protocols to produce Marburg infectious virus-like particles from R06E cells, which were then used to infect naïve target cells to investigate primary transcription. This was not possible with other cell lines previously tested. Moreover, we established protocols to reliably rescue recombinant Marburg viruses from R06E cells. CONCLUSION/SIGNIFICANCE: These data indicated that R06E cells are highly suitable to investigate the biology of filoviruses in cells derived from their presumed reservoir.

  1. Using the forest, people, fire agent-based social network model to investigate interactions in social-ecological systems

    Science.gov (United States)

    Paige Fischer; Adam Korejwa; Jennifer Koch; Thomas Spies; Christine Olsen; Eric White; Derric Jacobs

    2013-01-01

    Wildfire links social and ecological systems in dry-forest landscapes of the United States. The management of these landscapes, however, is bifurcated by two institutional cultures that have different sets of beliefs about wildfire, motivations for managing wildfire risk, and approaches to administering policy. Fire protection, preparedness, and response agencies often...

  2. Spontaneous transformation of murine oviductal epithelial cells: A model system to investigate the onset of fallopian-derived tumors

    Directory of Open Access Journals (Sweden)

    MIchael P. Endsley

    2015-07-01

    Full Text Available High-grade serous carcinoma (HGSC is the most lethal ovarian cancer histotype. The fallopian tube secretory epithelial cells (FTSECs are a proposed progenitor cell type. Genetically altered FTSECs form tumors in mice; however, a spontaneous HGSC model has not been described. Apart from a subpopulation of genetically predisposed women, most women develop ovarian cancer spontaneously, which is associated with aging and lifetime ovulations. A murine oviductal cell line (MOELOW was developed and continuously passaged in culture to mimic cellular aging (MOEHIGH. The MOEHIGH cellular model exhibited a loss of acetylated tubulin consistent with an outgrowth of secretory epithelial cells in culture. MOEHIGH cells proliferated significantly faster than MOELOW, and the MOEHIGH cells produced more 2D foci and 3D soft agar colonies as compared to MOELOW. MOEHIGH were xenografted into athymic female nude mice both in the subcutaneous and the intraperiteonal compartments. Only the subcutaneous grafts formed tumors that were negative for cytokeratin, but positive for oviductal markers such as oviductal glycoprotein 1 and Pax8. These tumors were considered to be poorly differentiated carcinoma. The differential molecular profiles between MOEHIGH and MOELOW were determined using RNA-Seq and confirmed by protein expression to uncover pathways important in transformation, like the p53 pathway, the FOXM1 pathway, WNT signaling, and splicing. MOEHIGH had enhanced protein expression of c-myc, Cyclin E, p53 and FOXM1 with reduced expression of p21. MOEHIGH were also less sensitive to cisplatin and DMBA, which induce lesions typically repaired by base-excision repair. A model of spontaneous tumorogenesis was generated starting with normal oviductal cells. Their transition to cancer involved alterations in pathways associated with high-grade serous cancer in humans.

  3. Theoretical investigation of two model systems for molecular photoswitch functionality. I. 2-(4-nitropyrimidin-2-yl)ethenol

    Science.gov (United States)

    Woywod, Clemens; Csehi, András; Halász, Gábor J.; Ruud, Kenneth; Vibók, Ágnes

    2014-03-01

    The ground and five lowest-lying electronically excited singlet states of 2-(4-nitropyrimidin-2-yl)ethenol (NPE) have been studied theoretically using the complete active space self-consistent-field (CASSCF), Møller-Plesset second-order perturbation theory (MP2) and second-order multi-configurational perturbation theory (CASPT2) methods. The molecule can be regarded as being composed of a frame and a crane component and is characterised by the existence of two planar minima of similar energy on the ground-state potential energy (PE) surface. This work explores the possibility of an excited-state intramolecular hydrogen transfer (ESIHT) process in NPE. A hypothetical reaction coordinate has been constructed for NPE. State-averaged CASSCF and CASPT2 calculations of the six lowest-lying singlet states have been performed for the isomerisation. Adiabatic and simplified quasi-diabatic PE and transition dipole moment functions have been constructed. The computations indicate that there exist substantial barriers for the rotation process on the adiabatic PE surfaces of all the five excited states investigated. The six quasi-diabatic electronic states considered here decompose into two classes based on whether the electronic wave functions depend weakly or strongly on the nuclear displacement, subject to the effect of the torsion on relevant molecular orbitals.

  4. Investigation of acetaminophen toxicity in HepG2/C3a microscale cultures using a system biology model of glutathione depletion.

    Science.gov (United States)

    Leclerc, Eric; Hamon, Jeremy; Claude, Isabelle; Jellali, Rachid; Naudot, Marie; Bois, Frederic

    2015-06-01

    We have integrated in vitro and in silico information to investigate acetaminophen (APAP) and its metabolite N-acetyl-p-benzoquinone imine (NAPQI) toxicity in liver biochip. In previous works, we observed higher cytotoxicity of HepG2/C3a cultivated in biochips when exposed to 1 mM of APAP for 72 h as compared to Petri cultures. We complete our investigation with the present in silico approach to extend the mechanistic interpretation of the intracellular kinetics of the toxicity process. For that purpose, we propose a mathematical model based on the coupling of a drug pharmacokinetic model (PK) with a systemic biology model (SB) describing the reactive oxygen species (ROS) production by NAPQI and the subsequent glutathione (GSH) depletion. The SB model was parameterized using (i) transcriptomic data, (ii) qualitative results of time lapses ROS fluorescent curves for both control and 1-mM APAP-treated experiments, and (iii) additional GSH literature data. The PK model was parameterized (i) using the in vitro kinetic data (at 160 μM, 1 mM, 10 mM), (ii) using the parameters resulting from a physiologically based pharmacokinetic (PBPK) literature model for APAP, and (iii) by literature data describing NAPQI formation. The PK-SB model predicted a ROS increase and GSH depletion due to the NAPQI formation. The transition from a detoxification phase and NAPQI and ROS accumulation was predicted for a NAPQI concentration ranging between 0.025 and 0.25 μM in the cytosol. In parallel, we performed a dose response analysis in biochips that shows a reduction of the final hepatic cell number appeared in agreement with the time and doses associated with the switch of the NAPQI detoxification/accumulation. As a result, we were able to correlate in vitro extracellular APAP exposures with an intracellular in silico ROS accumulation using an integration of a coupled mathematical and experimental liver on chip approach.

  5. Tourism recommendation system: empirical investigation

    OpenAIRE

    Petrevska, Biljana; Saso KOCESKI

    2012-01-01

    The paper makes an attempt to justify the necessity of implementing recommendation system which will assist tourists in identification of their ideal holiday. The proposed recommendation system based on collaborative filtering notes positive impulses in the case of Macedonia. A software module is developed being capable to generate a personalized list of favorable and tailor-made items. The research outcomes indicate that the designed national tourism web portal can provide satisfactory perfo...

  6. TOURISM RECOMMENDATION SYSTEM: EMPIRICAL INVESTIGATION

    Directory of Open Access Journals (Sweden)

    Biljana PETREVSKA

    2012-12-01

    Full Text Available The paper makes an attempt to justify the necessity of implementing recommendation system which will assist tourists in identification of their ideal holiday. The proposed recommendation system based on collaborative filtering notes positive impulses in the case of Macedonia. A software module is developed being capable to generate a personalized list of favorable and tailor-made items. The research outcomes indicate that the designed national tourism web portal can provide satisfactory performance and may be of high importance to all key-tourism actors in the process of identifying measures necessary for creating competitive tourism product.

  7. Numerical and experimental investigation of aeroviscoelastic systems

    Science.gov (United States)

    Martins, Polliana C. O.; Guimarães, Thiago A. M.; Pereira, Daniel de A.; Marques, Flávio D.; Rade, Domingos A.

    2017-02-01

    Viscoelastic materials have been widely used for the purpose of passive vibration mitigation in various types of mechanical systems, including, industrial machinery, civil structures and vehicles. In this paper, the use of those materials in aeroelastic systems is investigated, with emphasis placed on the influence of the viscoelastic behavior on the flutter speeds of two-degree-of-freedom typical section models, in which viscoelastic elements are introduced in addition to elastic elements associated to heave and pitch motions. The equations of motion of the aeroelastic system are modified to account for the dependence of the viscoelastic behavior on frequency and temperature, by using the concepts of complex modulus and shift factor. The aerodynamic forces and moments in subsonic regime are modeled according to Theodorsen's method. Numerical simulations are conducted to evaluate the influence of the addition of viscoelastic elements on the flutter speed and elucidate the separated influences of stiffness and damping additions. An experimental wind tunnel setup consisting of a rigid wing supported by flexible elements in pitch and plunge motions has been modified to enable the introduction of viscoelastic elements in parallel to those flexible elements. For various configurations of viscoelastic additions, the flutter instability is characterized from vibration measurements performed for increasing flow speeds in the vicinity of the stability boundary. The experimental results are used to validate the numerical model derived for the aeroviscoelastic system and confirm both qualitatively and quantitatively the predictions of the simulations, especially the possibility of increasing the flutter speed by the inclusion of viscoelastic materials.

  8. An Investigation of the Effects of Wave State and Sea Spray on an Idealized Typhoon Using an Air-Sea Coupled Modeling System

    Institute of Scientific and Technical Information of China (English)

    LIU Bin; GUAN Changlong; Li'an XIE; ZHAO Dongliang

    2012-01-01

    In this study,the impact of atmosphere-wave coupling on typhoon intensity was investigated using numerical simulations of an idealized typhoon in a coupled atmosphere-wave-ocean modeling system.The coupling between atmosphere and sea surface waves considered the effects of wave state and sea sprays on air-sea momentum flux,the atmospheric low-level dissipative heating,and the wave-state-affected seaspray heat flux. Several experiments were conducted to examine the impacts of wave state,sea sprays,and dissipative heating on an idealized typhoon system. Results show that considering the wave state and sea-spray-affected sea-surface roughness reduces typhoon intensity,while including dissipative heating intensifies the typhoon system.Taking into account sea spray heat flux also strengthens the typhoon system with increasing maximum wind speed and significant wave height.The overall impact of atmosphere- wave coupling makes a positive contribution to the intensification of the idealized typhoon system.The minimum central pressure simulated by the coupled atmosphere wave experiment was 16.4 hPa deeper than that of the control run,and the maximum wind speed and significant wave height increased by 31% and 4%,respectively.Meanwhile,within the area beneath the typhoon center,the average total upward air-sea heat flux increased by 22%,and the averaged latent heat flux increased more significantly by 31% compared to the uncoupled run.

  9. Smartphone Forensic Investigation Process Model

    OpenAIRE

    Archit Goel; Anurag Tyagi; Ankit Agarwal

    2012-01-01

    Law practitioners are in an uninterrupted battle with criminals in the application of computer/digital technologies, and these days the advancement in the use of Smartphones and social media has exponentially increased this risk. Thus it requires the development of a sound methodology to investigate Smartphones in a well defined and secured way. Computer fraud and digital crimes are growing rapidly and only very few cases result in confidence. Nowadays Smartphones accounts for the major porti...

  10. Serish inulin and wheat biopolymers interactions in model systems as a basis for understanding the impact of inulin on bread properties: a FTIR investigation.

    Science.gov (United States)

    Pourfarzad, Amir; Habibi Najafi, Mohammad B; Haddad Khodaparast, Mohammad H; Khayyat, Mohammad Hassanzadeh

    2015-12-01

    In this study the interactions between Serish root inulin and the main biopolymer types of wheat flour namely gluten, starch and phospholipid, were investigated in different model systems using Fourier transform infrared (FTIR) spectroscopy to unravel the underlying physical mechanism by which inulin impacts dough and bread properties. Interactions of inulin with starch and phospholipid were not considerable compared to gluten, but it was also clear that the modes of these interactions varied with the type and the amount of additives used in model formulation. This study revealed that when inulin is added to gluten, water redistribution promotes partial dehydration of gluten and collapse of β-spirals into intermolecular β-sheet structures; this trans-conformations might be due to physical reasons are believed to further impact the poor quality of bread containing added inulin. Upon performing Gaussian-Lorenzian curve fitting, it was observed that by adding of inulin to model systems, the relative contribution of characteristic peaks of β-turn and intramolecular β-sheet was progressively decreased whereas intermolecular β-sheet and α-helix contents were increased.

  11. Engineered high aspect ratio vertical nanotubes as a model system for the investigation of catalytic methanol synthesis over Cu/ZnO.

    Science.gov (United States)

    Güder, Firat; Frei, Elias; Kücükbayrak, Umut M; Menzel, Andreas; Thomann, Ralf; Luptak, Roman; Hollaender, Bernd; Krossing, Ingo; Zacharias, Margit

    2014-02-12

    Catalytically synthesized methanol from H2 and CO2 using porous Cu/ZnO aggregates is a promising, carbon neutral, and renewable alternative to replace fossil fuel based transport fuels. However, the absence of surface-engineered model systems to understand and improve the industrial Cu/ZnO catalyst poses a big technological gap in efforts to increase industrial methanol conversion efficiency. In this work, we report a novel process for the fabrication of patterned, vertically aligned high aspect ratio 1D nanostructures on Si that can be used as an engineered model catalyst. The proposed strategy employs near-field phase shift lithography (NF-PSL), deep reactive ion etching (DRIE), and atomic layer deposition (ALD) to pattern, etch, and coat Si wafers to produce high aspect ratio 1D nanostructures. Using this method, we produced a model system consisting of high aspect ratio Cu-decorated ZnO nanotubes (NTs) to investigate the morphological effects of ZnO catalyst support in comparison to the planar Cu/ZnO catalyst in terms of the catalytic reactions. The engineered catalysts performed 70 times better in activating CO2 than the industrial catalyst. In light of the obtained results, several important points are highlighted, and recommendations are made to achieve higher catalytic performance.

  12. A Regular Production-Remanufacturing Inventory Model for a Two-Echelon System with Price-dependent Return Rate and Environmental Effects Investigation

    Science.gov (United States)

    Dwicahyani, A. R.; Jauhari, W. A.; Jonrinaldi

    2017-06-01

    Product take-back recovery has currently became a promising effort for companies in order to create a sustainable supply chain. In addition, some restrictions including government regulations, social-ethical responsibilities, and up to economic factors have contributed to the reasons for the importance of product take-back recovery. This study aims to develop an inventory model in a system of reverse logistic management consisting of a manufacturer and a collector. Recycle dealer collects used products from the market and ships it to manufacturer. Manufacturer then recovers the used products and sell it eventually to the market. Some recovered products that can not be recovered as good as new one will be sold to the secondary market. In this study, we investigate the effects of environmental factors including GHG emissions and energy usage from transportation, regular production, and remanufacturing operations conducted by manufacturer and solve the model to get the maximum annual joint total profit for both parties. The model also considers price-dependent return rate and determine it as a decision variable as well as number of shipments from collector to manufacturer and optimal cycle period. An iterative procedure is proposed to determine the optimal solutions. We present a numerical example to illustrate the application of the model and perform a sensitivity analysis to study the effects of the changes in environmental related costs on the model’s decision.

  13. SYSTEM FOR THE ACADEMIC INVESTIGATION

    Directory of Open Access Journals (Sweden)

    Laura Leticia Laurent Martinez

    2006-11-01

    Full Text Available Generally, documental research depends on written bibliographical note cards that help find important text for a given research.However, the manual search for frequently used data such as author, publisher, topic, gets complicated as records increase resulting in a time consuming process that hinders the desired brainstorming.The software here presented solves two main issues: it allows a smoother and quicker data entry, and the flexibility to search by multiple criteria matching information for a specific author, publisher, topic, subtopic and date.The software also eases text transcription and builds the documental references that will be cited on research papers.The software is based on the object oriented (OO programming philosophy using Microsoft Access as a widely used relational database system.

  14. Continuous system modeling

    Science.gov (United States)

    Cellier, Francois E.

    1991-01-01

    A comprehensive and systematic introduction is presented for the concepts associated with 'modeling', involving the transition from a physical system down to an abstract description of that system in the form of a set of differential and/or difference equations, and basing its treatment of modeling on the mathematics of dynamical systems. Attention is given to the principles of passive electrical circuit modeling, planar mechanical systems modeling, hierarchical modular modeling of continuous systems, and bond-graph modeling. Also discussed are modeling in equilibrium thermodynamics, population dynamics, and system dynamics, inductive reasoning, artificial neural networks, and automated model synthesis.

  15. Laboratory-based experiments to investigate the impact of glyphosate-containing herbicide on pollution attenuation and biodegradation in a model pervious paving system.

    Science.gov (United States)

    Mbanaso, F U; Coupe, S J; Charlesworth, S M; Nnadi, E O

    2013-01-01

    An experimental investigation was carried out to determine the effect of glyphosate-containing herbicides (GCHs) on the hydrocarbon retention and biodegradation processes known to occur in pervious pavement systems (PPSs). The PPS test rigs were based on the four-layered design detailed in CIRIA C582. This enabled the pollutant retention capacity of the PPS and biodegradation of retained pollutants by microorganisms to be investigated. The use of test rigs also enabled the impact of GCH on PPS eukaryotic organisms to be studied, by the monitoring of protist bioindicators. Results showed that GCH disrupted hydrocarbon retention by the geotextiles relative to rigs with mineral oil only added, as 9.3% and 24.5% of added hydrocarbon were found in herbicide only rigs and herbicide plus oil rigs respectively. In previous studies, PPS contaminated by mineral oil had been shown to retain 98.7% of added oils and over several weeks, biodegrade this oil in situ. Where GCH was added to experimental models, much higher concentrations of heavy metals, including Pb, Cu, and Zn, were released from the PPS in effluent, particularly where GCH and mineral oil were added together. The source of the majority of the metal contamination was thought to be the used engine oil. The herbicide generally increased the total activity of microbial communities in rig systems and had a stimulating effect on bacterial and fungal population numbers. Although the protists, which are part of the microbial community directly or indirectly responsible for biodegradation, were initially strongly affected by the herbicide, they showed resilience by quickly recovering and increasing their population compared with rigs without added herbicide, including the rigs with mineral oil added to them. However, the presence of herbicide was associated with a decrease in the species richness of recorded protist taxa and a predominance of robust, cosmopolitan or ubiquitous protist genera.

  16. Flexible manufacturing system (FMS): The investigative phase

    Energy Technology Data Exchange (ETDEWEB)

    Setter, D.L.

    1992-02-01

    An investigation has been conducted into the feasibility of using flexible manufacturing system (FMS) technology to machine and inspect a family of stainless steel and aluminum parts for electrical components. The investigation was conducted by a user-oriented team of KCD personnel with the help of an outside consultant. The investigation showed that FMS was appropriate and justifiable for the KCD application. A project was initiated to purchase and implement an FMS system. 1 ref.

  17. Investigating the Role of Biogeochemical Processes in the Northern High Latitudes on Global Climate Feedbacks Using an Efficient Scalable Earth System Model

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Atul K. [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2016-09-14

    The overall objectives of this DOE funded project is to combine scientific and computational challenges in climate modeling by expanding our understanding of the biogeophysical-biogeochemical processes and their interactions in the northern high latitudes (NHLs) using an earth system modeling (ESM) approach, and by adopting an adaptive parallel runtime system in an ESM to achieve efficient and scalable climate simulations through improved load balancing algorithms.

  18. Experimental investigation and modelling of the interaction between an AVR and ballast load frequency controller in a stand-alone micro-hydroelectric system

    Energy Technology Data Exchange (ETDEWEB)

    Jarman, R.; Bryce, P. [University of Technology, Sydney, Broadway, NSW 2007 (Australia)

    2007-07-15

    Extensive field experience in micro-hydroelectric systems in remote rural communities demonstrates that the use of a typical automatic voltage regulator (AVR), as supplied with a brushless self-exciting synchronous alternator, can be the cause of unsatisfactory system performance. This paper presents results from experiments undertaken on a full-scale micro-hydroelectric test rig as well as system modelling with PSCAD. The source of the instability is considered to stem from the similar time constants of the ballast load frequency controller and the AVR as two competing feedback control systems. System modelling is used to verify steady state operating points, and confirms that the under-frequency roll-off characteristic of the AVR also contributes to unsatisfactory performance. (author)

  19. Investigating the Performance of One- and Two-dimensional Flood Models in a Channelized River Network: A Case Study of the Obion River System

    Science.gov (United States)

    Kalyanapu, A. J.; Dullo, T. T.; Thornton, J. C.; Auld, L. A.

    2015-12-01

    Obion River, is located in the northwestern Tennessee region, and discharges into the Mississippi River. In the past, the river system was largely channelized for agricultural purposes that resulted in increased erosion, loss of wildlife habitat and downstream flood risks. These impacts are now being slowly reversed mainly due to wetland restoration. The river system is characterized by a large network of "loops" around the main channels that hold water either from excess flows or due to flow diversions. Without data on each individual channel, levee, canal, or pond it is not known where the water flows from or to. In some segments along the river, the natural channel has been altered and rerouted by the farmers for their irrigation purposes. Satellite imagery can aid in identifying these features, but its spatial coverage is temporally sparse. All the alterations that have been done to the watershed make it difficult to develop hydraulic models, which could predict flooding and droughts. This is especially true when building one-dimensional (1D) hydraulic models compared to two-dimensional (2D) models, as the former cannot adequately simulate lateral flows in the floodplain and in complex terrains. The objective of this study therefore is to study the performance of 1D and 2D flood models in this complex river system, evaluate the limitations of 1D models and highlight the advantages of 2D models. The study presents the application of HEC-RAS and HEC-2D models developed by the Hydrologic Engineering Center (HEC), a division of the US Army Corps of Engineers. The broader impacts of this study is the development of best practices for developing flood models in channelized river systems and in agricultural watersheds.

  20. Studies of Catalytic Model Systems

    DEFF Research Database (Denmark)

    Holse, Christian

    The overall topic of this thesis is within the field of catalysis, were model systems of different complexity have been studied utilizing a multipurpose Ultra High Vacuum chamber (UHV). The thesis falls in two different parts. First a simple model system in the form of a ruthenium single crystal...... is investigated. Second the development of a complex Cu/ZnO nanoparticle model system is described and gas-induced dynamical changes in the model system is investigated. The ruthenium crystal serves as an extremely simple model for studying CO dissociation which is the rate limiting step of the methanation...... process. The Ru(0 1 54) surface is studied by means of Scanning Tunneling Microscopy (STM), Temperature Programmed Desoprtion (TPD), and Oxygen Titration (OT) experiments. Real space evidence of periodic features on every second monatomic step is observed via STM when the a clean ruthenium surface...

  1. Measuring the success of business-intelligence systems in South Africa: An empirical investigation applying the DeLone and McLean Model

    Directory of Open Access Journals (Sweden)

    Taurayi Mudzana

    2015-02-01

    Full Text Available Background: Business intelligence systems (BIS hold promise for improving organisational decision-making in South Africa. Yet, the use of BIS has been associated with a number of challenges. Objectives: The aim of the study was to identify post implementation factors that contribute to the success of BIS in South African organisations.Method: This study draws on the DeLone and McLean Model of Information Systems success and recent literature on business-intelligence (BI to develop and test a BIS success model. A quantitative study was conducted in the form of a survey of 102 BI users to validate the BIS success model. Results: Five interrelated factors of BIS success were confirmed. The study found that the quality of information has a strong influence on system use and user satisfaction. It was found that system quality is positively associated with user satisfaction. The results also indicated that service quality is negatively related to user satisfaction. The study also found that user satisfaction is positively associated with nett benefits of a BI system.Conclusion: The study provides insights for both managers and practitioners on the factors to focus on when implementing BIS thereby minimising the adoption risks associated with BI failures.

  2. Aerodynamic and Mechanical System Modelling

    DEFF Research Database (Denmark)

    Jørgensen, Martin Felix

    This thesis deals with mechanical multibody-systems applied to the drivetrain of a 500 kW wind turbine. Particular focus has been on gearbox modelling of wind turbines. The main part of the present project involved programming multibody systems to investigate the connection between forces, moments...

  3. Modelling Railway Interlocking Systems

    DEFF Research Database (Denmark)

    Lindegaard, Morten Peter; Viuf, P.; Haxthausen, Anne Elisabeth

    2000-01-01

    In this report we present a model of interlocking systems, and describe how the model may be validated by simulation. Station topologies are modelled by graphs in which the nodes denote track segments, and the edges denote connectivity for train traÆc. Points and signals are modelled by annotatio...

  4. An Observing System Simulation Experiment (OSSE) Investigating the OMI Aerosol Products Using Simulated Aerosol and Atmospheric Fields from the NASA GEOS-5 Model

    Science.gov (United States)

    Colarco, P. R.; Gasso, S.; Jethva, H. T.; Buchard, V.; Ahn, C.; Torres, O.; daSilva, A.

    2016-12-01

    Output from the NASA Goddard Earth Observing System, version 5 (GEOS-5) Earth system model is used to simulate the top-of-atmosphere 354 and 388 nm radiances observed by the Ozone Monitoring Instrument (OMI) onboard the Aura spacecraft. The principle purpose of developing this simulator tool is to compute from the modeled fields the so-called OMI Aerosol Index (AI), which is a more fundamental retrieval product than higher level products such as the aerosol optical depth (AOD) or absorbing aerosol optical depth (AAOD). This lays the groundwork for eventually developing a capability to assimilate either the OMI AI or its radiances, which would provide further constraint on aerosol loading and absorption properties for global models. We extend the use of the simulator capability to understand the nature of the OMI aerosol retrieval algorithms themselves in an Observing System Simulation Experiment (OSSE). The simulated radiances are used to calculate the AI from the modeled fields. These radiances are also provided to the OMI aerosol algorithms, which return their own retrievals of the AI, AOD, and AAOD. Our assessment reveals that the OMI-retrieved AI can be mostly harmonized with the model-derived AI given the same radiances provided a common surface pressure field is assumed. This is important because the operational OMI algorithms presently assume a fixed pressure field, while the contribution of molecular scattering to the actual OMI signal in fact responds to the actual atmospheric pressure profile, which is accounted for in our OSSE by using GEOS-5 produced atmospheric reanalyses. Other differences between the model and OMI AI are discussed, and we present a preliminary assessment of the OMI AOD and AAOD products with respect to the known inputs from the GEOS-5 simulation.

  5. Metrological models and calibration pads in the system of radioecological investigations over large territories by the method of gamma-ray spectrometry

    Science.gov (United States)

    Khaykovich, I. M.; Serykh, A. S.; Luchin, I. A.; Fominykh, V. I.

    1995-10-01

    A comparative evaluation has been earned out on models for the metrological assurance of instrumental methods which are designed to assess the composition of natural formations when studying radiation situations over large territories, and which are based on spectrometric measurements of γ-radiation from natural beds. Recommendations are given concerning the choice of metrological models in relation to the solution of the main radioecological task. i.e. investigation of the distributions of radionuclides of artificial (technogenic) origin and natural radioactive elements. Here we describe the principles for the selection of calibration pads which correspond to the chosen models; also the procedures for their certification and application for calibration measuring instruments—portable, car-borne and airborne γ-ray spectrometers (multi-channel geophysical γ-radiometers).

  6. Investigations of medium sized solar combi systems

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    2006-01-01

    A large variety of solar combi systems are on the market, but it is still too early to draw conclusions on optimum design of solar combi systems. Among others, the following questions need to be answered: Is an external domestic hot water preparation more desirable than an internal? What...... is the advantage by using inlet stratifiers? To answer the questions, theoretical investigations are carried out for differently designed solar combi systems. The work is carried out within the Solar Heating and Cooling Programme of the International Energy Agency (IEA SHC), Task 32 Advanced storage concepts...... for solar houses and low energy buildings....

  7. Time-resolved EPR investigation of potential model systems for acrylate polymer main chain radicals based on esters of Kemp's tri-acid.

    Science.gov (United States)

    Lebedeva, Natalia V; Gorelik, Elena V; Magnus-Aryitey, Damaris; Hill, Terence E; Forbes, Malcolm D E

    2009-05-14

    Methyl esters of Kemp's tri-acid and cyclohexanetricarboxylic acid are structurally similar to acrylate polymers, having the same functionalities and stereoregularities as poly(methylmethacrylate) and poly(methylacrylate), respectively. The photochemistry and free radicals from these model systems have been studied using time-resolved electron paramagnetic resonance spectroscopy with laser flash photolysis at 248 nm. Chemically induced electron spin polarization from the triplet mechanism (net emission) is observed. Well-resolved spectra are obtained at all temperatures for the model system radicals, which are determined to be in the slow motion condition, that is, there is no interconversion of chair conformations. The temperature dependence of the spectra is minimal; some hyperfine lines shift as the temperature increases, but without much broadening. Density functional theory calculations are presented and discussed in support of the experimental data.

  8. Investigation of Controls on Ice Dynamics in Northeast Greenland from Ice-Thickness Change Record Using Ice Sheet System Model (ISSM)

    Science.gov (United States)

    Csatho, B. M.; Larour, E. Y.; Schenk, A. F.; Schlegel, N.; Duncan, K.

    2015-12-01

    We present a new, complete ice thickness change reconstruction of the NE sector of the Greenland Ice Sheet for 1978-2014, partitioned into changes due to surface processes and ice dynamics. Elevation changes are computed from all available stereoscopic DEMs, and laser altimetry data (ICESat, ATM, LVIS). Surface Mass Balance and firn-compaction estimates are from RACMO2.3. Originating nearly at the divide of the Greenland Ice Sheet (GrIS), the dynamically active North East Ice Stream (NEGIS) is capable of rapidly transmitting ice-marginal forcing far inland. Thus, NEGIS provides a possible mechanism for a rapid drawdown of ice from the ice sheet interior as marginal warming, thinning and retreat continues. Our altimetry record shows accelerating dynamic thinning of Zachariæ Isstrom, initially limited to the deepest part of the fjord near the calving front (1978-2000) and then extending at least 75 km inland. At the same time, changes over the Nioghalvfjerdsfjorden (N79) Glacier are negligible. We also detect localized large dynamic changes at higher elevations on the ice sheet. These thickness changes, often occurring at the onset of fast flow, could indicate rapid variations of basal lubrication due to rerouting of subglacial drainage. We investigate the possible causes of the observed spatiotemporal pattern of ice sheet elevation changes using the Ice Sheet System Model (ISSM). This work build on our previous studies examining the sensitivity of ice flow within the Northeast Greenland Ice Stream (NEGIS) to key fields, including ice viscosity, basal drag. We assimilate the new altimetry record into ISSM to improve the reconstruction of basal friction and ice viscosity. Finally, airborne geophysical (gravity, magnetic) and ice-penetrating radar data is examined to identify the potential geologic controls on the ice thickness change pattern. Our study provides the first comprehensive reconstruction of ice thickness changes for the entire NEGIS drainage basin during

  9. Investigating complex networks with inverse models

    CERN Document Server

    Wens, Vincent

    2014-01-01

    Recent advances in neuroscience have motivated the study of network organization in spatially distributed dynamical systems from indirect measurements. However, the associated connectivity estimation, when combined with inverse modeling, is strongly affected by spatial leakage. We formulate this problem in a general framework and develop a new approach to model spatial leakage and limit its effects. It is analytically compared to existing regression-based methods used in electrophysiology, which are shown to yield biased estimates of amplitude and phase couplings.

  10. Development, investigation and modelling of a micro reformer as part of a system for off-grid power supply with PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Rochlitz, Lisbeth

    2008-11-18

    In this thesis a micro reformer fuel cell system ({mu}RFCS) for 300 Wel off-grid power supply, fuelled with bioethanol, was simulated, designed, developed and investigated in a test-rig. First a literature study was carried through to point out the specific characteristics of micro reforming, the most important being heat transfer, and present the systems currently under research and already on the market. As a next step, the processes of the RFCS were simulated with the commercial simulation tool CHEMCAD. This comprised thermodynamic equilibrium simulations for the separate reactions of steam reforming, water gas shift and selective methanation. It also included a simulation of the complete {mu}RFCS with thermodynamic equilibrium for all reactors and assumed values for heat loss and fuel cell efficiency. The resulting net electrical efficiency was 24%. As a third step, a reaction pathway scheme with parallel and serial reactions for the steam reforming reaction of ethanol was simulated, developed, evaluated and proven plausible by matching the simulation to experimental results obtained in the {mu}RFCS test rig. The equilibrium simulations were used to evaluate the catalyst screening carried through for reformer, water gas shift and selective methanation catalysts. The catalysts for the {mu}RFCS were chosen and the optimum operating conditions determined by the screening tests. Having accomplished the simulation and design of the system, the largest proportion of this work was spent on the construction, set-up, testing and evaluation of the complete {mu}RFCS. The focus for the evaluations lay on the reformer side of the system. The technical feasibility was demonstrated for an ethanol/water mix of 3 ml/min at S/C 3. The first tests without optimized heat and water management between the reformer system and the fuel cell system resulted in power output of around 115 W{sub el}, at a total electrical efficiency of 31%. (orig.)

  11. Framework to investigate emergence in system engineering

    CSIR Research Space (South Africa)

    Oosthuizen, R

    2011-09-01

    Full Text Available for Scientific and Industrial Research, South Africa roosthuizen@csir.co.za 2StoneToStars Limited, New Zealand henkroodt@xtra.co.nz 3 Graduate School of Technology Management University of Pretoria, South Africa leon.Pretorius@up.ac.za ABSTRACT... such as the undermining of safe usage of a system and unforeseen catastrophes, such as the Uberlingen air disaster and 2003 North American blackout. Had emergence been investigated within these systems, catastrophe could have been averted. Fromm [7] lists...

  12. Plastic pipe systems failure investigation and diagnosis

    CERN Document Server

    Farshad, Mehdi

    2011-01-01

    Industrial and domestic piping is increasingly made from various plastics and composites, and these materials withstand heavy use over long periods. They are, however, affected by environmental and other factors over time and can degrade, causing major problems within piping systems. Farshad's book deals with why plastic pipes and systems fail, and with how to investigate and diagnose such failures. Pipes may buckle, fracture, change in dimensions and colour, blister and delaminate, corrode through stress, be abraded and obstructed: all these cause problems and lead to loss of efficient operat

  13. Investigation of ifosfamide and chloroacetaldehyde renal toxicity through integration of in vitro liver-kidney microfluidic data and pharmacokinetic-system biology models.

    Science.gov (United States)

    Leclerc, Eric; Hamon, Jeremy; Bois, Frederic Yves

    2016-02-01

    We have integrated in vitro and in silico data to describe the toxicity of chloroacetaldehyde (CAA) on renal cells via its production from the metabolism of ifosfamide (IFO) by hepatic cells. A pharmacokinetic (PK) model described the production of CAA by the hepatocytes and its transport to the renal cells. A system biology model was coupled to the PK model to describe the production of reactive oxygen species (ROS) induced by CAA in the renal cells. In response to the ROS production, the metabolism of glutathione (GSH) and its depletion were modeled by the action of an NFE2L2 gene-dependent pathway. The model parameters were estimated in a Bayesian context via Markov Chain Monte Carlo (MCMC) simulations based on microfluidic experiments and literature in vitro data. Hepatic IFO and CAA in vitro intrinsic clearances were estimated to be 1.85 x 10(-9) μL s(-1) cell(-1) and 0.185 x 10(-9) μL s(-1) cell(-1) ,respectively (corresponding to an in vivo intrinsic IFO clearance estimate of 1.23 l h(-1) , to be compared to IFO published values ranging from 3 to 10 l h(-1) ). After model calibration, simulations made at therapeutic doses of IFO showed CAA renal intracellular concentrations ranging from 11 to 131 μM. Intracellular CAA concentrations above 70 μM induced intense ROS production and GSH depletion. Those responses were time and dose dependent, showing transient and non-linear kinetics. Those results are in agreement with literature data reporting that intracellular CAA toxic concentrations range from 35 to 320 μM, after therapeutic ifosfamide dosing. The results were also consistent with in vitro CAA renal cytotoxicity data.

  14. Numerical Investigation of Floor Heating Systems in Low Energy Houses

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Kragh, Jesper; Jensen, Claus Franceos

    2002-01-01

    . The model calculates heating demand, room temperatures, and thermal comfort parameters for a person in the room. The model is based on a numerical Finite Control Volume (FCV) method for the heat transfer in walls, ceiling, windows and floor. The model uses both convective and radiative heat transfer...... – a heavy system integrated into the concrete floor and a light system which is placed in heat transfer plates – have been investigated, using different supply temperatures to the floor heating system, and different control strategies. The aim of the study is to compare the two types of floor heating......In this paper an investigation of floor heating systems is performed with respect to heating demand and room temperature. Presently (2001) no commercially available building simulation programs that can be used to evaluate heating demand and thermal comfort in buildings with building integrated...

  15. Selected System Models

    Science.gov (United States)

    Schmidt-Eisenlohr, F.; Puñal, O.; Klagges, K.; Kirsche, M.

    Apart from the general issue of modeling the channel, the PHY and the MAC of wireless networks, there are specific modeling assumptions that are considered for different systems. In this chapter we consider three specific wireless standards and highlight modeling options for them. These are IEEE 802.11 (as example for wireless local area networks), IEEE 802.16 (as example for wireless metropolitan networks) and IEEE 802.15 (as example for body area networks). Each section on these three systems discusses also at the end a set of model implementations that are available today.

  16. COMMON PHASES OF COMPUTER FORENSICS INVESTIGATION MODELS

    Directory of Open Access Journals (Sweden)

    Yunus Yusoff

    2011-06-01

    Full Text Available The increasing criminal activities using digital information as the means or targets warrant for a structured manner in dealing with them. Since 1984 when a formalized process been introduced, a great number of new and improved computer forensic investigation processes have been developed. In this paper, we reviewed a few selected investigation processes that have been produced throughout the yearsand then identified the commonly shared processes. Hopefully, with the identification of the commonly shard process, it would make it easier for the new users to understand the processes and also to serve as the basic underlying concept for the development of a new set of processes. Based on the commonly shared processes, we proposed a generic computer forensics investigation model, known as GCFIM.

  17. Investigation and modelling of fuel utilisation in the zone near the burner of technical combustion systems. Final report; Untersuchung und Modellierung der Brennstoffumsetzung im Brennernahbereich technischer Verbrennungssysteme. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, H.; Wirtz, S.

    1999-06-01

    Optimisation and development of technical combustion systems in order to generate energy efficiently and reduce pollution is an ever-increasing challenge. Mathematical and numerical simulations play a very important role in this context. This project was dedicated to the implementation and improvement of mathematical models and subsequent verification of the modelling concepts. Verification used data measured by the university department for combined cyle turbines. The focal point of interest was the reaction zone near the burner. Further points of interest: development and improvement of models for two-phase effects, fuel consumption and turbulence interaction as well as further development of the methods of numerical simulation. Simulating the combustion chamber of the combined cycle turbines was prioritised.(orig.) [German] Die Optimierung und Weiterentwicklung technischer Verbrennungssysteme mit dem Ziel einer moeglichst effizienten und schadstoffarmen Energiebereitstellung stellt eine staendig wachsende Herausforderung dar. Bei der technologischen Umsetzung dieses Ziels kommt der mathematisch-numerischen Simulation eine immer groessere Bedeutung zu. In diesem Projekt sollte die Implementierung und Verbesserung von mathematischen Modellierungsansaetzen sowie die anschliessende Verifikation der Modellierungskonzepte anhand der Messdaten des Lehrstuhls fuer Dampf- und Gasturbinen (LDuG) durchgefuehrt werden. Der Schwerpunkt lag in der brennernahen Reaktionszone. Konkrete Arbeitsschwerpunkte waren die Weiterentwicklung und Verbesserung der Modellansaetze fuer Zweiphaseneffekte, Brennstoffumsatz und Turbulenzinteraktion sowie die Weiterentwicklung der Methodik der numerischen Simulation. Dabei stand die Simulation der Brennkammer des LDuG im Vordergrund. (orig.)

  18. Modeling cellular systems

    CERN Document Server

    Matthäus, Franziska; Pahle, Jürgen

    2017-01-01

    This contributed volume comprises research articles and reviews on topics connected to the mathematical modeling of cellular systems. These contributions cover signaling pathways, stochastic effects, cell motility and mechanics, pattern formation processes, as well as multi-scale approaches. All authors attended the workshop on "Modeling Cellular Systems" which took place in Heidelberg in October 2014. The target audience primarily comprises researchers and experts in the field, but the book may also be beneficial for graduate students.

  19. Multiscale Cloud System Modeling

    Science.gov (United States)

    Tao, Wei-Kuo; Moncrieff, Mitchell W.

    2009-01-01

    The central theme of this paper is to describe how cloud system resolving models (CRMs) of grid spacing approximately 1 km have been applied to various important problems in atmospheric science across a wide range of spatial and temporal scales and how these applications relate to other modeling approaches. A long-standing problem concerns the representation of organized precipitating convective cloud systems in weather and climate models. Since CRMs resolve the mesoscale to large scales of motion (i.e., 10 km to global) they explicitly address the cloud system problem. By explicitly representing organized convection, CRMs bypass restrictive assumptions associated with convective parameterization such as the scale gap between cumulus and large-scale motion. Dynamical models provide insight into the physical mechanisms involved with scale interaction and convective organization. Multiscale CRMs simulate convective cloud systems in computational domains up to global and have been applied in place of contemporary convective parameterizations in global models. Multiscale CRMs pose a new challenge for model validation, which is met in an integrated approach involving CRMs, operational prediction systems, observational measurements, and dynamical models in a new international project: the Year of Tropical Convection, which has an emphasis on organized tropical convection and its global effects.

  20. Numerical Modeling of Microelectrochemical Systems

    DEFF Research Database (Denmark)

    Adesokan, Bolaji James

    for the reactants in the bulk electrolyte that are traveling waves. The first paper presents the mathematical model which describes an electrochemical system and simulates an electroanalytical technique called cyclic voltammetry. The model is governed by a system of advection–diffusion equations with a nonlinear...... reaction term at the boundary. We investigate the effect of flow rates, scan rates, and concentration on the cyclic voltammetry. We establish that high flow rates lead to the reduced hysteresis in the cyclic voltammetry curves and increasing scan rates lead to more pronounced current peaks. The final part...... of the paper shows that the response current in a cyclic voltammetry increases proportionally to the electrolyte concentration. In the second paper we present an experiment of an electrochemical system in a microfluidc system and compare the result to the numerical solutions. We investigate how the position...

  1. Book Review: System Forensics, Investigation, and Response

    Directory of Open Access Journals (Sweden)

    Nate Keith

    2012-06-01

    Full Text Available Vacca, J. R. and Rudolph, K. (2011. System Forensics, Investigation, and Response. Sudbury, MA: Jones and Bartlett Learning. 339 + xv pages, ISBN: 978-0-7637-9134-6, US$89.95.Reviewed by Nate Keith, MBA, (natejkeith@gmail.comI recently expressed an interest to a respected colleague in finding a way to “give back” to the forensic community. He suggested writing a review for a text he recently received and provide feedback to the community. It is my intent to present an objective analysis of System Forensics, Investigation, and Response.Written by John R. Vacca and K Rudolph, this book is part of the Jones and Bartlett Learning Information Systems Security & Assurance Series.  Both Vacca and Rudolph have considerable experience in the information technology field as is demonstrated by the back cover notes: “John R. Vacca is an information technology consultant and internationally known best-selling author based in Pomeroy, Ohio.  Since 1982, he has written 62 books and more than 600 articles in the areas of advanced storage, computer security, and aerospace technology.(see PDF for full review

  2. Dynamic Systems Modeling

    Directory of Open Access Journals (Sweden)

    Sorin Dan ŞANDOR

    2003-01-01

    Full Text Available System Dynamics was introduced by Jay W. Forrester in the 1960s. Since then the methodology was adopted in many areas of natural or social sciences. This article tries to present briefly how this methodology works, both as Systems Thinking and as Modelling with Vensim computer software.

  3. Modeling Sustainable Food Systems

    Science.gov (United States)

    Allen, Thomas; Prosperi, Paolo

    2016-05-01

    The processes underlying environmental, economic, and social unsustainability derive in part from the food system. Building sustainable food systems has become a predominating endeavor aiming to redirect our food systems and policies towards better-adjusted goals and improved societal welfare. Food systems are complex social-ecological systems involving multiple interactions between human and natural components. Policy needs to encourage public perception of humanity and nature as interdependent and interacting. The systemic nature of these interdependencies and interactions calls for systems approaches and integrated assessment tools. Identifying and modeling the intrinsic properties of the food system that will ensure its essential outcomes are maintained or enhanced over time and across generations, will help organizations and governmental institutions to track progress towards sustainability, and set policies that encourage positive transformations. This paper proposes a conceptual model that articulates crucial vulnerability and resilience factors to global environmental and socio-economic changes, postulating specific food and nutrition security issues as priority outcomes of food systems. By acknowledging the systemic nature of sustainability, this approach allows consideration of causal factor dynamics. In a stepwise approach, a logical application is schematized for three Mediterranean countries, namely Spain, France, and Italy.

  4. Predicting Geotechnical Investigation Using the Knowledge Based System

    Directory of Open Access Journals (Sweden)

    Bojan Žlender

    2016-01-01

    Full Text Available The purpose of this paper is to evaluate the optimal number of investigation points and each field test and laboratory test for a proper description of a building site. These optimal numbers are defined based on their minimum and maximum number and with the equivalent investigation ratio. The total increments of minimum and maximum number of investigation points for different building site conditions were determined. To facilitate the decision-making process for a number of investigation points, an Adaptive Network Fuzzy Inference System (ANFIS was proposed. The obtained fuzzy inference system considers the influence of several entry parameters and computes the equivalent investigation ratio. The developed model (ANFIS-SI can be applied to characterize any building site. The ANFIS-SI model takes into account project factors which are evaluated with a rating from 1 to 10. The model ANFIS-SI, with integrated recommendations can be used as a systematic decision support tool for engineers to evaluate the number of investigation points, field tests, and laboratory tests for a proper description of a building site. The determination of the optimal number of investigative points and the optimal number of each field test and laboratory test is presented on reference case.

  5. System and method for investigating arterial remodeling.

    Science.gov (United States)

    Rachev, Alexander; Dominguez, Zachary; Vito, Raymond

    2009-10-01

    Organ culture systems are used to study remodeling of arteries and to fabricate tissue engineered vascular grafts. Investigations to date focused on changes in geometry and mechanical response of arteries or constructs associated with controlled sustained alterations in the global load parameters such as the arterial pressure, flow, or axial stretch. A new experimental paradigm is proposed, which is based on the simultaneous independent control of local mechanical parameters such as mean strain or stress in the arterial wall and flow-induced shear at the intima. An organ culture system and methodology were developed, which controls pressure, flow, and axial length of a specimen in order to maintain the local mechanical parameters at prescribed values. The operation of the system is illustrated by maintenance of elevated axial medial stress in porcine carotid artery, while keeping the mean circumferential stress and flow-induced shear stress at baseline values. Previously unknown aspects of remodeling that might be revealed by the novel approach are discussed.

  6. Modeling Complex Systems

    CERN Document Server

    Boccara, Nino

    2010-01-01

    Modeling Complex Systems, 2nd Edition, explores the process of modeling complex systems, providing examples from such diverse fields as ecology, epidemiology, sociology, seismology, and economics. It illustrates how models of complex systems are built and provides indispensable mathematical tools for studying their dynamics. This vital introductory text is useful for advanced undergraduate students in various scientific disciplines, and serves as an important reference book for graduate students and young researchers. This enhanced second edition includes: . -recent research results and bibliographic references -extra footnotes which provide biographical information on cited scientists who have made significant contributions to the field -new and improved worked-out examples to aid a student’s comprehension of the content -exercises to challenge the reader and complement the material Nino Boccara is also the author of Essentials of Mathematica: With Applications to Mathematics and Physics (Springer, 2007).

  7. Distributed generation systems model

    Energy Technology Data Exchange (ETDEWEB)

    Barklund, C.R.

    1994-12-31

    A slide presentation is given on a distributed generation systems model developed at the Idaho National Engineering Laboratory, and its application to a situation within the Idaho Power Company`s service territory. The objectives of the work were to develop a screening model for distributed generation alternatives, to develop a better understanding of distributed generation as a utility resource, and to further INEL`s understanding of utility concerns in implementing technological change.

  8. Modeling the earth system

    Energy Technology Data Exchange (ETDEWEB)

    Ojima, D. [ed.

    1992-12-31

    The 1990 Global Change Institute (GCI) on Earth System Modeling is the third of a series organized by the Office for Interdisciplinary Earth Studies to look in depth at particular issues critical to developing a better understanding of the earth system. The 1990 GCI on Earth System Modeling was organized around three themes: defining critical gaps in the knowledge of the earth system, developing simplified working models, and validating comprehensive system models. This book is divided into three sections that reflect these themes. Each section begins with a set of background papers offering a brief tutorial on the subject, followed by working group reports developed during the institute. These reports summarize the joint ideas and recommendations of the participants and bring to bear the interdisciplinary perspective that imbued the institute. Since the conclusion of the 1990 Global Change Institute, research programs, nationally and internationally, have moved forward to implement a number of the recommendations made at the institute, and many of the participants have maintained collegial interactions to develop research projects addressing the needs identified during the two weeks in Snowmass.

  9. Investigation of the industrial clusters in Islamic Republic of Iran (Case Study of Yazd city usinglocal production systems method &Industry Perception Model

    Directory of Open Access Journals (Sweden)

    Seyed Valiollah MirHosseini

    2011-10-01

    Full Text Available All countries hope to achieve increasingly developments which grow fast. Nowadays many developed countries are using strategy of industrial clusters development because they influence the competitiveness of industrial clusters in the country as well as beyond national borders and show new ways of thinking about the place of dealing and earning. Industrial clusters influence competition through increasing of productivity based on settlement of companies and providing quick guidelines for development and innovation and encouraging of new business. Industrial cluster is one of new combined methods of various theories such as theory of economic geography, regional economics, national innovation system, transmitting knowledge theories, social capital theories and social networks .Recently this method in Iran attracted many attentions based on industries compatible with mentioned method which attempts to provide a better and competitive market place for the country, region and the world. In this study literature of industrial clusters is initially reviewed and then data analysis methods, used model and eventually results of this paper will be dealt with.

  10. A View of Earth System Model Development

    Institute of Scientific and Technical Information of China (English)

    ZHOU Tianjun; YU Yongqiang; WANG Bin

    2009-01-01

    This paper gives a definition of earth system model and shows three development phases of it, including physical climate system model, earth climate system model, and earth system model, based on an inves-tigation of climate system models in the world. It provides an expatiation on the strategic significance of future development of earth system model, an introduction of some representative scientific research plans on development of earth system model home and abroad, and a review of its status and trends based on the models of the fourth assessment report (AR4) of the Intergovernmental Panel on Climate Change (IPCC).Some suggestions on future development of earth system model in China are given, which are expected to be helpful to advance the development.

  11. Investigation and modelling of flow phenomena at ball poppet valves of mobile hydraulic systems; Untersuchung und Modellbildung zu Stroemungsphaenomenen an Kugelsitzventilen der Mobilhydraulik

    Energy Technology Data Exchange (ETDEWEB)

    Karl, Andreas

    2008-07-01

    The author attempts the modelling of flow-physical phenomena at an electrohydraulic ball poppet valve. The focus is on reducing the complexity of nonlinear flow models. The flow, and especially the pressure curve which is relevant for the valve function, is modelled on the basis of the Navier-Stokes equations. Complexity reduction is achieved by a quasi-one-dimensional approach and a separation approach of physical influencing factors (ISPE approach) and is applied exemplarily on flow in the valve seat. By introducing a friction and momentum coefficient, the relevant mathematical terms can be weighted selectively and physically founded, e.g. for adaption to reference results. A stream tube model is used for modelling the region ahead of the valve seat. Both modelling regions are modular and can be coupled as desired. Owing to the insufficient accessibility for measuring of the pressure field of interest and for avoiding interferences, the two approaches are validated by means of CFD simulations. (orig.)

  12. A Comprehensive Investigation Into Modeling Supernovae Spectra

    Science.gov (United States)

    Hillier, Desmond

    Supernovae are a rich source of information. By studying their light curves and spectra we gain insights into stellar evolution, the nature of the progenitor star, surface abundances at the time of the explosion, whether previous mass-loss episodes have occurred, the physics of the explosion including the amount and type of elements synthesized, and whether the explosion has produced significant mixing between shells of different chemical composition. To maximize the information that can be gleaned from observations of supernovae it is essential that we have the necessary spectroscopic tools. To this end, we are developing a code, CMFGEN, capable of modeling supernova light curves and spectra. The code is currently being used, to study core-collapse supernovae as well as those arising from the nuclear detonation of a White Dwarf star. We wish to extend CMFGEN's capabilities by developing a procedure to handle non-monotonic velocity flows so that we can treat shock breakout and the interaction of supernova ejecta with circumstellar material. We will also investigate magnetar-powered SNe, and explore the connection between Type Ib and Type Ic supernovae and those supernovae associated with long-duration gamma-ray bursters. Through detailed studies of individual supernova, and through the construction of model grids, we are able to infer deficiencies in our modeling, in our atomic data, and in the progenitor models, and hence make refinements so that we can improve our understanding of all SNe classes. Previous (IUE), current (HST, Chandra, GALEX), and future NASA missions (James Webb Telescope) do/will provide a wealth of data on supernovae. The proposed research is related to strategic subgoal 3D: "Discover the origin, structure, evolution, and destiny of the universe, and search for Earth-like planets." Supernovae are inherently coupled to the evolution of the universe and life: They can trigger star formation and they provide the raw materials (e.g., oxygen

  13. Mechanical Systems, Classical Models

    CERN Document Server

    Teodorescu, Petre P

    2009-01-01

    This third volume completes the Work Mechanical Systems, Classical Models. The first two volumes dealt with particle dynamics and with discrete and continuous mechanical systems. The present volume studies analytical mechanics. Topics like Lagrangian and Hamiltonian mechanics, the Hamilton-Jacobi method, and a study of systems with separate variables are thoroughly discussed. Also included are variational principles and canonical transformations, integral invariants and exterior differential calculus, and particular attention is given to non-holonomic mechanical systems. The author explains in detail all important aspects of the science of mechanics, regarded as a natural science, and shows how they are useful in understanding important natural phenomena and solving problems of interest in applied and engineering sciences. Professor Teodorescu has spent more than fifty years as a Professor of Mechanics at the University of Bucharest and this book relies on the extensive literature on the subject as well as th...

  14. Numerical Investigation of Floor Heating Systems in Low Energy Houses

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Kragh, Jesper; Jensen, Claus Franceos

    2002-01-01

    to the room air and between the room surfaces. The simulation model has been used to calculate heating demand and room temperature in a typical well insulated Danish single-family house with a heating demand of approximately 6000 kWh per year, for a 130 m² house. Two different types of floor heating systems......In this paper an investigation of floor heating systems is performed with respect to heating demand and room temperature. Presently (2001) no commercially available building simulation programs that can be used to evaluate heating demand and thermal comfort in buildings with building integrated...... heating and cooling systems exist. In Denmark over 80 % of all new single-family houses are using the building integrated floor heating systems. Therefore methods to evaluate building integrated heating must be developed. To examine this a simulation model of a room with floor heating has been created...

  15. NEP systems model

    Science.gov (United States)

    George, Jeffrey A.

    A new nuclear electric propulsion (NEP) systems analysis code is discussed. The new code is modular and consists of a driver code and various subsystem models. The code models five different subsystems: (1) reactor/shield; (2) power conversion; (3) heat rejection; (4) power management and distribution (PMAD); and (5) thrusters. The code optimizes for the following design criteria: minimum mass; minimum radiator area; and low mass/low area. The code also optimizes the following parameters: separation distance; temperature ratio; pressure ratio; and transmission frequency. The discussion is presented in vugraph form.

  16. Computational models of complex systems

    CERN Document Server

    Dabbaghian, Vahid

    2014-01-01

    Computational and mathematical models provide us with the opportunities to investigate the complexities of real world problems. They allow us to apply our best analytical methods to define problems in a clearly mathematical manner and exhaustively test our solutions before committing expensive resources. This is made possible by assuming parameter(s) in a bounded environment, allowing for controllable experimentation, not always possible in live scenarios. For example, simulation of computational models allows the testing of theories in a manner that is both fundamentally deductive and experimental in nature. The main ingredients for such research ideas come from multiple disciplines and the importance of interdisciplinary research is well recognized by the scientific community. This book provides a window to the novel endeavours of the research communities to present their works by highlighting the value of computational modelling as a research tool when investigating complex systems. We hope that the reader...

  17. National Energy Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, C.W. (Energy Information Administration, Washington, DC (United States))

    1993-01-01

    The Energy Information Administration is developing a new National Energy Modeling System to provide annual forecasts of energy supply, demand, and prices on a regional basis in the United States and, to a limited extent, in the rest of the world. The design for the system was based on a requirements analysis, a comparison of requirements with existing modeling capabilities, and a series of widely circulated issue papers defining the choices and tradeoffs for 13 key design decisions. An initial prototpye of the new NEMS was implemented in late 1992, with a more complete, operational version in 1993. NEMS is expected to provide EIA and other users with a greatly enhanced ability to illustrate quickly and effectively the effects of a wide range of energy policy proposals.

  18. INVESTIGATION OF RATTLING THRESHOLD IN GEAR SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Dong Haijun; Shen Yunwen; Liu Mengjun; Wang Sanmin

    2005-01-01

    A lumped mass gear-rattling model with backlash is established by considering the time varying mesh stiffness, composite transmission error and the torque fluctuation. Based on the principle that no separation will occur if the response amplitude is not larger than the static response,the threshold is obtained by theoretical derivation. The validity of the theoretical derivation is verified by the numerical method. The results show that the time-varying mesh stiffness has little effect on the threshold. When the exciting frequency is less than the system natural frequency, the theoretical agrees well with the numerical one. The higher the exciting frequency or the smaller the average input torque is, the easier the separation will occur. When the exciting frequency is larger than the natural frequency by a certain value, the theoretical threshold does not agree with the numerical results. The numerical results show that the motion state will change from the meshing state to the separating state directly. The phenomenon that the gear pair sometimes separates and sometimes meshes occurs only when the exciting frequency is smaller.

  19. Investigation of rotor control system loads

    Institute of Scientific and Technical Information of China (English)

    Sun Tao; Tan Jianfeng; Wang Haowen

    2013-01-01

    This paper concentrates on the aeroelasticity analysis of rotor blade and rotor control systems. A new multi-body dynamics model is established to predict both rotor pitch link loads and swashplate servo loads. Two helicopter rotors of UH-60A and SA349/2, both operating in two critical flight conditions, high-speed flight and high-thrust flight, are studied. The analysis shows good agreements with the flight test data and the calculation results using CAMRAD II. The mechanisms of rotor control loads are then analyzed in details based on the present predictions and the flight test data. In high-speed conditions, the pitch link loads are dominated by the integral of blade pitching moments, which are generated by cyclic pitch control. In high-thrust conditions, the positive pitching loads in the advancing side are caused by high collective pitch angle, and dynamic stall in the retreating side excites high-frequency responses. The swashplate servo loads are predominated by the rotor pitch link loads, and the inertia of the swashplate has significant effects on high-frequency harmonics of the servo loads.

  20. Modeling Novo Nordisk Production Systems

    DEFF Research Database (Denmark)

    Miller, Thomas Dedenroth

    1997-01-01

    This report describes attributes of models and systems, and how models can be used for description of production systems. There are special attention on the 'Theory of Domains'.......This report describes attributes of models and systems, and how models can be used for description of production systems. There are special attention on the 'Theory of Domains'....

  1. Investigation of FE model size definition for surface coating application

    Science.gov (United States)

    Chen, Yanhong; Zhuang, Weimin; Wang, Shiwen; Lin, Jianguo; Balint, Daniel; Shan, Debin

    2012-09-01

    An efficient prediction mechanical performance of coating structures has been a constant concern since the dawn of surface engineering. However, predictive models presented by initial research are normally based on traditional solid mechanics, and thus cannot predict coating performance accurately. Also, the high computational costs that originate from the exclusive structure of surface coating systems (a big difference in the order of coating and substrate) are not well addressed by these models. To fill the needs for accurate prediction and low computational costs, a multi-axial continuum damage mechanics (CDM)-based constitutive model is introduced for the investigation of the load bearing capacity and fracture properties of coatings. Material parameters within the proposed constitutive model are determined for a typical coating (TiN) and substrate (Cu) system. An efficient numerical subroutine is developed to implement the determined constitutive model into the commercial FE solver, ABAQUS, through the user-defined subroutine, VUMAT. By changing the geometrical sizes of FE models, a series of computations are carried out to investigate (1) loading features, (2) stress distributions, and (3) failure features of the coating system. The results show that there is a critical displacement corresponding to each FE model size, and only if the applied normal loading displacement is smaller than the critical displacement, a reasonable prediction can be achieved. Finally, a 3D map of the critical displacement is generated to provide guidance for users to determine an FE model with suitable geometrical size for surface coating simulations. This paper presents an effective modelling approach for the prediction of mechanical performance of surface coatings.

  2. Investigations and practices on green manufacturing in machining systems

    Institute of Scientific and Technical Information of China (English)

    LIU Fei; YIN Jia-xu; CAO Hua-jun; HE Yan

    2005-01-01

    A machining system is a typical manufacturing system. A green manufacturing function framework of machining systems is structured to describe the traits of input, output and control elements in the system. Based on the function framework, the green manufacturing problem framework of machining systems is presented. The green manufacturing problems in machining systems are classified into three classes and related series of subclass problems. The three classes of problems in the green manufacturing problem framework are the problems of the minimization of resource consumption, the minimization of environmental discharge, and the synthesized minimization of both of them. A series of investigations and practices on green manufacturing in machining system, performed by the authors for quite a long period, are introduced in brief, such as the optimizing system for raw material cutting,the matching system for energy-saving in machining, the design of highly efficient dry hobbing machine tools, the multi-objective decision-making model for green manufacturing in machining systems, and the decision-making supporting system for green manufacturing in machining processes.

  3. Resin polymer and corrosion casting of the porcine pelvi-calyceal system: a useful model for investigating new imaging and endoscopic techniques of the upper urinary tract.

    Science.gov (United States)

    John, Babbin; Ghani, Khurshid R; Patel, Uday; Anson, Ken

    2008-02-01

    We describe the use of polyester resin casting of the pelvi-calyceal (PC) system as a method of evaluating the accuracy of new three-dimensional imaging technology such as ultrasound and computerised tomography. Thirty-eight kidneys from large white pigs were used for the study. We describe the process of preparation of the kidney and polyester resin for injection into the PC systems. The setting process of the resin is an exothermic reaction with an associated change in consistency. The PC systems of the kidneys were injected with resin in a controlled manner and casts obtained by maceration of the kidneys. Some of these kidneys had been distended previously with 11% glycerol and three-dimensional ultrasound reconstructions of their PC systems were compared to resin casts to assess accuracy of the reconstructions. Thirty-eight casts were created out of which 13 were poor. The quality of the casts improved with practice and pelvi-calyceal morphology could be faithfully recreated. Controlled perfusion and watching for signs such as a "turgid feel" of the kidney help avoid pelvi-calyceal disruption. Anatomically accurate casts of the kidney PC system can be created using polyester resin with the technique described. These casts can be a useful research and training tool with urological and radiological applications.

  4. Investigating Output Accuracy for a Discrete Event Simulation Model and an Agent Based Simulation Model

    CERN Document Server

    Majid, Mazlina Abdul; Siebers, Peer-Olaf

    2010-01-01

    In this paper, we investigate output accuracy for a Discrete Event Simulation (DES) model and Agent Based Simulation (ABS) model. The purpose of this investigation is to find out which of these simulation techniques is the best one for modelling human reactive behaviour in the retail sector. In order to study the output accuracy in both models, we have carried out a validation experiment in which we compared the results from our simulation models to the performance of a real system. Our experiment was carried out using a large UK department store as a case study. We had to determine an efficient implementation of management policy in the store's fitting room using DES and ABS. Overall, we have found that both simulation models were a good representation of the real system when modelling human reactive behaviour.

  5. The control of climate and base-level change on the stratigraphic architecture of fluvio-deltaic systems, investigated by quantitative analogue modelling

    NARCIS (Netherlands)

    Berg van Saparoea, Aart-Peter van den

    2005-01-01

    River systems play an important role in the filling of sedimentary basins and record the history of external forcing processes, such as climate, tectonics and sea-level change, acting on them. They are potential reservoirs for oil, gas and water, and can host coal and placer mineral deposits. Becaus

  6. System of systems modeling and analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, James E.; Anderson, Dennis James; Longsine, Dennis E. (Intera, Inc., Austin, TX); Shirah, Donald N.

    2005-01-01

    This report documents the results of an LDRD program entitled 'System of Systems Modeling and Analysis' that was conducted during FY 2003 and FY 2004. Systems that themselves consist of multiple systems (referred to here as System of Systems or SoS) introduce a level of complexity to systems performance analysis and optimization that is not readily addressable by existing capabilities. The objective of the 'System of Systems Modeling and Analysis' project was to develop an integrated modeling and simulation environment that addresses the complex SoS modeling and analysis needs. The approach to meeting this objective involved two key efforts. First, a static analysis approach, called state modeling, has been developed that is useful for analyzing the average performance of systems over defined use conditions. The state modeling capability supports analysis and optimization of multiple systems and multiple performance measures or measures of effectiveness. The second effort involves time simulation which represents every system in the simulation using an encapsulated state model (State Model Object or SMO). The time simulation can analyze any number of systems including cross-platform dependencies and a detailed treatment of the logistics required to support the systems in a defined mission.

  7. Summary of multi-core hardware and programming model investigations

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Suzanne Marie; Pedretti, Kevin Thomas Tauke; Levenhagen, Michael J.

    2008-05-01

    This report summarizes our investigations into multi-core processors and programming models for parallel scientific applications. The motivation for this study was to better understand the landscape of multi-core hardware, future trends, and the implications on system software for capability supercomputers. The results of this study are being used as input into the design of a new open-source light-weight kernel operating system being targeted at future capability supercomputers made up of multi-core processors. A goal of this effort is to create an agile system that is able to adapt to and efficiently support whatever multi-core hardware and programming models gain acceptance by the community.

  8. Parameter estimation and investigation of a bolted joint model

    Science.gov (United States)

    Shiryayev, O. V.; Page, S. M.; Pettit, C. L.; Slater, J. C.

    2007-11-01

    Mechanical joints are a primary source of variability in the dynamics of built-up structures. Physical phenomena in the joint are quite complex and therefore too impractical to model at the micro-scale. This motivates the development of lumped parameter joint models with discrete interfaces so that they can be easily implemented in finite element codes. Among the most important considerations in choosing a model for dynamically excited systems is its ability to model energy dissipation. This translates into the need for accurate and reliable methods to measure model parameters and estimate their inherent variability from experiments. The adjusted Iwan model was identified as a promising candidate for representing joint dynamics. Recent research focused on this model has exclusively employed impulse excitation in conjunction with neural networks to identify the model parameters. This paper presents an investigation of an alternative parameter estimation approach for the adjusted Iwan model, which employs data from oscillatory forcing. This approach is shown to produce parameter estimates with precision similar to the impulse excitation method for a range of model parameters.

  9. Investigation of Self-Oscillation using Particle Balance Model

    Science.gov (United States)

    Bae, Inshik; Na, Byungkeun; Chang, Hongyoung

    2015-09-01

    Self-oscillation, which is obtained by using a DC-only power supply with specific anode voltage conditions, is investigated in a cylindrical system with thermal electrons using tungsten filaments. From analysis of the obtained oscillation profiles, the experimental data is consistent with the model derived from the particle balance model. The self-oscillation period characteristics with respect to the pressure and gas species are also analyzed. As the physics and particle motion of self-oscillation near the electron avalanche is analyzed in different perspective, this study may advance the understanding of this phenomenon. This research was supported by the Ministry of Knowledge Economy (MKE) of Korea (Grant No. 10041681).

  10. Investigating the productivity model for clinical nurses.

    Science.gov (United States)

    Dehghan Nayeri, Nahid; Hooshmand Bahabadi, Abbas; Kazemnejad, Anoshirvan

    2014-01-01

    One of the main objectives of quantitative researches is assessment of models developed by qualitative studies. Models validation through their testing implies that the designed model is representative of the existed facts. Hence, this study was conducted to assess the clinical nurses' productivity model presented for Iranian nurses' productivity. The sample of the study consisted of 360 nurses of Tehran University of Medical Sciences. The research tool was a questionnaire for measuring the components of clinical nurses' productivity. After completing all steps of instrument psychometric and getting answers from the participants, the factors introduced in the questionnaire were named and then Lisrel Path Analysis tests were performed to analyze the components of the model. The results of the model test revealed there is an internal relationship among different components of the model. Regression Analysis showed that each increasing unit in components of the model was to be added to central variable of productivity model -human resource. Model components altogether explained 20 % of clinical nurses' productivity variance. This study found that the important component of productivity is human resources that are reciprocally related to other components of the model. Therefore, it can be stated that the managers can promote the productivity by using efficient strategies to correct human resource patterns.

  11. Investigation of novel thermoelectric refrigeration systems

    OpenAIRE

    Ma, Xiaoli

    2004-01-01

    Concern over global warming and depletion of the ozone layer has stimulated research to develop cooling methods that do not employ environmentally damaging working fluids such as CFCs and HCFCs. Two methods that have been considered are absorption and thermoelectric `Peltier' cooling systems. Absorption systems, using H20/LiBr have the advantage of being able to use low-grade waste heat. However, the large volume, high capital cost and low performance of these systems have inhibited their wid...

  12. A Predictive Model for Investigating Seagrass Paleoecology, Biogeography and Diversity

    Science.gov (United States)

    Sewall, J. O.; Clementz, M. T.

    2008-12-01

    Seagrasses are highly productive components of coastal ecosystems that play significant roles in the flow of nutrients and the modulation of physical conditions within the world's oceans. However, in spite of the significant role seagrasses play today, the fossil record contains little evidence of the distribution and abundance of seagrass species in the past and many questions about their biology, ecology, and evolutionary history remain. We have developed, and present here, a parameter driven numerical model of global seagrass biogeography and diversity appropriate for paleontological and paleoecological investigations. The global distribution of seagrasses in our model is dependent on four input parameters, water temperature, water salinity, water depth, and photosynthetically available radiation at depth. With these limited inputs, our model captures both the location and biodiversity of modern seagrass distributions well. The simplicity of our model and its robust representation of modern conditions give it tremendous flexibility for applications throughout the ~70 Ma long history of seagrasses. Paleo ocean temperatures, salinity, water depths, and incident radiation are available from paleoclimatic/proxy datasets and/or numerical simulations of past environmental/climatic conditions, thus permitting investigations into time specific seagrass biogeography and diversity throughout its evolutionary history. In addition, the simplicity of our model allows for theoretical investigations of seagrass paleoecology and response to environmental changes. Both applications will contribute significantly to furthering our understanding of seagrasses, seagrass dominated ecosystems, and the roles they have played in the earth system over the past 70 Ma.

  13. 337Info - Unfair Import Investigations Information System

    Data.gov (United States)

    US International Trade Commission — The 337Info database contains data relating to Section 337 investigations instituted, or otherwise initiated, by the U.S. International Trade Commission on or after...

  14. Investigation of the photochemical changes of chlorogenic acids induced by ultraviolet light in model systems and in agricultural practice with Stevia rebaudiana cultivation as an example.

    Science.gov (United States)

    Karaköse, Hande; Jaiswal, Rakesh; Deshpande, Sagar; Kuhnert, Nikolai

    2015-04-08

    Mono- and diacyl chlorogenic acids undergo photochemical trans-cis isomerization under ultraviolet (UV) irradiation. The photochemical equilibrium composition was established for eight selected derivatives. In contrast to all other dicaffeoylquinic acid derivatives, cynarin (1,3-dicaffeoylquinic acid) undergoes a [2 + 2] photochemical cycloaddition reaction, constituting a first example of Schmidt's law in a natural product family. The relevance of photochemical isomerization in agricultural practice was investigated using 120 samples of Stevia rebaudiana leave samples grown under defined cultivation conditions. Ratios of cis to trans chlorogenic acids were determined in leaf samples and correlated with climatic and harvesting conditions. The data indicate a clear correlation between the formation of cis-caffeoyl derivatives and sunshine hours prior to harvesting and illustrate the relevance of UV exposure to plant material affecting its phytochemical composition.

  15. Investigation of capacitively coupled ultrasonic transducer system for nondestructive evaluation.

    Science.gov (United States)

    Zhong, Cheng Huan; Wilcox, Paul D; Croxford, Anthony J

    2013-12-01

    Capacitive coupling offers a simple solution to wirelessly probe ultrasonic transducers. This paper investigates the theory, feasibility, and optimization of such a capacitively coupled transducer system (CCTS) in the context of nondestructive evaluation (NDE) applications. The noncontact interface relies on an electric field formed between four metal plates-two plates are physically connected to the electrodes of a transducer, the other two are in a separate probing unit connected to the transmit/receive channel of the instrumentation. The complete system is modeled as an electric network with the measured impedance of a bonded piezoelectric ceramic disc representing a transducer attached to an arbitrary solid substrate. A transmission line model is developed which is a function of the physical parameters of the capacitively coupled system, such as the permittivity of the material between the plates, the size of the metal plates, and their relative positions. This model provides immediate prediction of electric input impedance, pulse-echo response, and the effect of plate misalignment. The model has been validated experimentally and has enabled optimization of the various parameters. It is shown that placing a tuning inductor and series resistor on the transmitting side of the circuit can significantly improve the system performance in terms of the signal-to-crosstalk ratio. Practically, bulk-wave CCTSs have been built and demonstrated for underwater and through-composite testing. It has been found that electrical conduction in the media between the plates limits their applications.

  16. Investigations of medium sized solar combi systems

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    2006-01-01

    A large variety of solar combi systems are on the market, but it is still too early to draw conclusions on optimum design of solar combi systems. Among others, the following questions need to be answered: Is an external domestic hot water preparation more desirable than an internal? What is the a...

  17. System dynamics modelling of situation awareness

    CSIR Research Space (South Africa)

    Oosthuizen, R

    2015-11-01

    Full Text Available . The feedback loops and delays in the Command and Control system also contribute to the complex dynamic behavior. This paper will build on existing situation awareness models to develop a System Dynamics model to support a qualitative investigation through...

  18. Investigating the performance of a minienvironment system

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Tengfang

    2005-05-20

    A minienvironment is a localized environment created by an enclosure to isolate a product or process from the surrounding environment. Minienvironments have been gaining popularity to provide effective containment for critical contamination control. The use of minienvironments can provide several orders of magnitude improvement in particle cleanliness levels, while energy intensity may be shifted from the conventional cleanroom systems to the minienvironments that enclose the specific process. The purpose of this paper is to study the energy performance of a minienvironment air system in a ballroom setting, to quantify power density of such a system, and to identify areas for energy savings from high-performance minienvironments.

  19. Simulation Modeling Method and Experimental Investigation on the Uniflow Scavenging System of an Opposed-Piston Folded-Cranktrain Diesel Engine

    Directory of Open Access Journals (Sweden)

    Fukang Ma

    2017-05-01

    Full Text Available The scavenging process for opposed-piston folded-cranktrain (OPFC diesel engines can be described by the time evolution of the in-cylinder and exhaust chamber residual gas rates. The relation curve of in-cylinder and exhaust chamber residual gas rate is called scavenging profile, which is calculated through the changes of in-cylinder and exhaust chamber gas compositions determined by computational fluid dynamics (CFD simulation. The scavenging profile is used to calculate the scavenging process by mono-dimensional (1D simulation. The tracer gas method (TGM is employed to validate the accuracy of the scavenging profile. At the same time, the gas exchange performance under different intake and exhaust state parameters was examined based on the TGM. The results show that the scavenging process from 1D simulation and experiment match well, which means the scavenging model obtained by CFD simulation performs well and validation of its effectiveness by TGM is possible. The difference between intake and exhaust pressure has a significant positive effect on the gas exchange performance and trapped gas mass, but the pressure difference has little effect on the scavenging efficiency and the trapped air mass if the delivery ratio exceeds 1.4.

  20. Investigating surety methodologies for cognitive systems.

    Energy Technology Data Exchange (ETDEWEB)

    Caudell, Thomas P. (University of New Mexico, Albuquerque, NM); Peercy, David Eugene; Mills, Kristy (University of New Mexico, Albuquerque, NM); Caldera, Eva (University of New Mexico, Albuquerque, NM)

    2006-11-01

    Advances in cognitive science provide a foundation for new tools that promise to advance human capabilities with significant positive impacts. As with any new technology breakthrough, associated technical and non-technical risks are involved. Sandia has mitigated both technical and non-technical risks by applying advanced surety methodologies in such areas as nuclear weapons, nuclear reactor safety, nuclear materials transport, and energy systems. In order to apply surety to the development of cognitive systems, we must understand the concepts and principles that characterize the certainty of a system's operation as well as the risk areas of cognitive sciences. This SAND report documents a preliminary spectrum of risks involved with cognitive sciences, and identifies some surety methodologies that can be applied to potentially mitigate such risks. Some potential areas for further study are recommended. In particular, a recommendation is made to develop a cognitive systems epistemology framework for more detailed study of these risk areas and applications of surety methods and techniques.

  1. Adaptable data management for systems biology investigations

    Directory of Open Access Journals (Sweden)

    Burdick David

    2009-03-01

    Full Text Available Abstract Background Within research each experiment is different, the focus changes and the data is generated from a continually evolving barrage of technologies. There is a continual introduction of new techniques whose usage ranges from in-house protocols through to high-throughput instrumentation. To support these requirements data management systems are needed that can be rapidly built and readily adapted for new usage. Results The adaptable data management system discussed is designed to support the seamless mining and analysis of biological experiment data that is commonly used in systems biology (e.g. ChIP-chip, gene expression, proteomics, imaging, flow cytometry. We use different content graphs to represent different views upon the data. These views are designed for different roles: equipment specific views are used to gather instrumentation information; data processing oriented views are provided to enable the rapid development of analysis applications; and research project specific views are used to organize information for individual research experiments. This management system allows for both the rapid introduction of new types of information and the evolution of the knowledge it represents. Conclusion Data management is an important aspect of any research enterprise. It is the foundation on which most applications are built, and must be easily extended to serve new functionality for new scientific areas. We have found that adopting a three-tier architecture for data management, built around distributed standardized content repositories, allows us to rapidly develop new applications to support a diverse user community.

  2. Investigating Tactile Stimulation in Symbiotic Systems

    DEFF Research Database (Denmark)

    Orso, Valeria; Mazza, Renato; Gamberini, Luciano

    2017-01-01

    The core characteristics of tactile stimuli, i.e., recognition reliability and tolerance to ambient interference, make them an ideal candidate to be integrated into a symbiotic system. The selection of the appropriate stimulation is indeed important in order not to hinder the interaction from the...

  3. Investigation and Modelling of Diesel Hydrotreating Reactions

    DEFF Research Database (Denmark)

    Boesen, Rasmus Risum

    This project consists of a series of studies, that are related to hydrotreating of diesel. Hy- drotreating is an important refinery process, in which the oil stream is upgraded to meet the required environmental specifications and physical properties. Although hydrotreating is a ma- ture technology...... on a commercial CoMo catalyst, and a simple kinetic model is presented. Hydrogenation of fused aromatic rings are known to be fast, and it is possible, that the reaction rates are limited by either internal or external mass transfer. An experiment conducted at industrial temperatures and pressure, using...... kinetic models. Hydrogenation reactions are quite fast, and in order to avoid mass transfer limitations, and only measure intrinsic rates, experiments are often conducted, at conditions that are milder than in industrial units. A reactor model for a Robinson-Mahoney reactor that takes mass transfer...

  4. Investigation on wind energy-compressed air power system

    Institute of Scientific and Technical Information of China (English)

    贾光政; 王宣银; 吴根茂

    2004-01-01

    Wind energy is a pollution free and renewable resource widely distributed over China. Aimed at protecting the environment and enlarging application of wind energy, a new approach to application of wind energy by using compressed air power to some extent instead of electricity put forward. This includes: explaining the working principles and characteristics of the wind energy-compressed air power system; discussing the compatibility of wind energy and compressor capacity; presenting the theoretical model and computational simulation of the system. The obtained compressor capacity vs wind power relationship in certain wind velocity range can be helpful in the designing of the wind power-compressed air system. Results of investigations on the application of high-pressure compressed air for pressure reduction led to conclusion that pressure reduction with expander is better than the throttle regulator in energy saving.

  5. Investigating models for associating fluids using spectroscopy

    DEFF Research Database (Denmark)

    von Solms, Nicolas; Michelsen, Michael Locht; Passos, Claudia Pereira;

    2005-01-01

    Two equations of state (PC-SAFT and CPA) are used to predict the monomer fraction of pure associating fluids. The models each require five pure-component parameters usually obtained by fitting to experimental liquid density and vapor pressure data. Here we also incorporate monomer fractions...

  6. Statistical analysis of accurate prediction of local atmospheric optical attenuation with a new model according to weather together with beam wandering compensation system: a season-wise experimental investigation

    Science.gov (United States)

    Arockia Bazil Raj, A.; Padmavathi, S.

    2016-07-01

    Atmospheric parameters strongly affect the performance of Free Space Optical Communication (FSOC) system when the optical wave is propagating through the inhomogeneous turbulent medium. Developing a model to get an accurate prediction of optical attenuation according to meteorological parameters becomes significant to understand the behaviour of FSOC channel during different seasons. A dedicated free space optical link experimental set-up is developed for the range of 0.5 km at an altitude of 15.25 m. The diurnal profile of received power and corresponding meteorological parameters are continuously measured using the developed optoelectronic assembly and weather station, respectively, and stored in a data logging computer. Measured meteorological parameters (as input factors) and optical attenuation (as response factor) of size [177147 × 4] are used for linear regression analysis and to design the mathematical model that is more suitable to predict the atmospheric optical attenuation at our test field. A model that exhibits the R2 value of 98.76% and average percentage deviation of 1.59% is considered for practical implementation. The prediction accuracy of the proposed model is investigated along with the comparative results obtained from some of the existing models in terms of Root Mean Square Error (RMSE) during different local seasons in one-year period. The average RMSE value of 0.043-dB/km is obtained in the longer range dynamic of meteorological parameters variations.

  7. ECO-BIOLOGICAL SYSTEM MODELING

    Directory of Open Access Journals (Sweden)

    T. I. Burak

    2015-01-01

    Full Text Available The methodology for computer modeling of complex eco-biological models is presented in this paper. It is based on system approach of J. Forrester. Developed methodology is universal for complex ecological and biological systems. Modeling algorithm considers specialties of eco-biological systems and shows adequate and accurate results in practice. 

  8. System Level Modelling and Performance Estimation of Embedded Systems

    DEFF Research Database (Denmark)

    Tranberg-Hansen, Anders Sejer

    is simulation based and allows performance estimation to be carried out throughout all design phases ranging from early functional to cycle accurate and bit true descriptions of the system, modelling both hardware and software components in a unied way. Design space exploration and performance estimation...... an efficient system level design methodology, a modelling framework for performance estimation and design space exploration at the system level is required. This thesis presents a novel component based modelling framework for system level modelling and performance estimation of embedded systems. The framework...... is performed by having the framework produce detailed quantitative information about the system model under investigation. The project is part of the national Danish research project, Danish Network of Embedded Systems (DaNES), which is funded by the Danish National Advanced Technology Foundation. The project...

  9. Investigation of stressful life events in patients with systemic sclerosis

    Institute of Scientific and Technical Information of China (English)

    Yue CHEN; Ji-zhong HUANG; Yu QIANG; Jin WANG; Mao-mao HAN

    2008-01-01

    Objective: To assess the occurrence of stressful life events in the year before the initiation of systemic sclerosis. Methods: A consecutive series of 40 patients with systemic sclerosis (mean age (56.3~ 11.9) years, mean disease duration (4.3±3.1) years; 32 females and 8 males), including 28 with diffuse cutaneous scleroderma and 12 with limited cutaneous scleroderma, were evaluated. A control group of 40 healthy subjects free of systemic sclerosis also was included. Socioeconomic status was inves-tigated and Paykel's interview for recent life events (a semi-structured research interview covering 64 life events) was conducted. Results: Patients with systemic sclerosis showed higher percentages of lower education (72.5%) and working class (82.5%), and reported more stressful life events (P<0.05), such as exits (P<0.05), undesirable events (P<0.01), and uncontrolled events (P<0.001), when compared with the control. More events that had an objective negative impact (P<0.001) were also reported in systemic sclerosis patients than in the control. These results are in accordance with a muitifactorial model of pathogenesis in systemic sclerosis. Conclusion: We reported a strong relationship between stressful life events and the initiation of systemic sclerosis. Our findings are consistent with current understanding of the extensive links of behavioral responses to stress with neurophysiological and biochemical processes.

  10. Investigating interventions in Alzheimer's disease with computer simulation models.

    Directory of Open Access Journals (Sweden)

    Carole J Proctor

    Full Text Available Progress in the development of therapeutic interventions to treat or slow the progression of Alzheimer's disease has been hampered by lack of efficacy and unforeseen side effects in human clinical trials. This setback highlights the need for new approaches for pre-clinical testing of possible interventions. Systems modelling is becoming increasingly recognised as a valuable tool for investigating molecular and cellular mechanisms involved in ageing and age-related diseases. However, there is still a lack of awareness of modelling approaches in many areas of biomedical research. We previously developed a stochastic computer model to examine some of the key pathways involved in the aggregation of amyloid-beta (Aβ and the micro-tubular binding protein tau. Here we show how we extended this model to include the main processes involved in passive and active immunisation against Aβ and then demonstrate the effects of this intervention on soluble Aβ, plaques, phosphorylated tau and tangles. The model predicts that immunisation leads to clearance of plaques but only results in small reductions in levels of soluble Aβ, phosphorylated tau and tangles. The behaviour of this model is supported by neuropathological observations in Alzheimer patients immunised against Aβ. Since, soluble Aβ, phosphorylated tau and tangles more closely correlate with cognitive decline than plaques, our model suggests that immunotherapy against Aβ may not be effective unless it is performed very early in the disease process or combined with other therapies.

  11. INTEGRATED HYDROGEN STORAGE SYSTEM MODEL

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, B

    2007-11-16

    makes it difficult to remove the heat of reaction, especially in the relatively short target refueling times, see Attachment 3. This document describes a detailed numerical model for general metal hydride beds that couples reaction kinetics with heat and mass transfer, for both hydriding and dehydriding of the bed. The detailed model is part of a comprehensive methodology for the design, evaluation and modification of hydrogen storage systems. In Hardy [2007], scoping models for reaction kinetics, bed geometry and heat removal parameters are discussed. The scoping models are used to perform a quick assessment of storage systems and identify those which have the potential to meet DOE performance targets. The operational characteristics of successful candidate systems are then evaluated with the more detailed models discussed in this document. The detailed analysis for hydrogen storage systems is modeled in either 2 or 3-dimensions, via the general purpose finite element solver COMSOL Multiphysics{reg_sign}. The two-dimensional model serves to provide rapid evaluation of bed configurations and physical processes, while the three-dimensional model, which requires a much longer run time, is used to investigate detailed effects that do not readily lend themselves to two-dimensional representations. The model is general and can be adapted to any geometry or storage media. In this document, the model is applied to a modified cylindrical shell and tube geometry with radial fins perpendicular to the axis, see Figures 4.1-1 and 4.1-2. Sodium alanate, NaAlH{sub 4}, is used as the hydrogen storage medium. The model can be run on any DOS, LINUX or Unix based system.

  12. A Simulation Based Investigation of High Latency Space Systems Operations

    Science.gov (United States)

    Li, Zu Qun; Moore, Michael; Bielski, Paul; Crues, Edwin Z.

    2017-01-01

    This study was the first in a series of planned tests to use physics-based subsystem simulations to investigate the interactions between a spacecraft's crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation models the life support system of a deep space habitat. It contains models of an environmental control and life support system, an electrical power system, an active thermal control systems, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the subsystems; 2) a mission control center interface with data transport delays up to 15 minute each way; and 3) a real-time simulation test conductor interface used to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission. The NEEMO crew and ground support team performed a number of relevant deep space mission scenarios that included both nominal activities and activities with system malfunctions. While this initial test sequence was focused on test infrastructure and procedures development, the data collected in the study already indicate that long communication delays have notable impacts on the operation of deep space systems. For future human missions beyond cis-lunar, NASA will need to design systems and support tools to meet these challenges. These will be used to train the crew to handle critical malfunctions on their own, to predict malfunctions and assist with vehicle operations. Subsequent more detailed and involved studies will be conducted to continue advancing NASA's understanding of space systems operations across long communications delays.

  13. Notation systems for transcription: an empirical investigation.

    Science.gov (United States)

    Romero, Catherine; O'Connell, Daniel C; Kowal, Sabine

    2002-11-01

    A 21-syllable question posed by Bernard Shaw in a CNN television interview with Margaret Thatcher was presented to 90 participants, either as an audio recording or as a typed transcript or as both. Participants were asked to speak it, as closely as possible, as Shaw had (or, in conditions without the audio recording, as he might have). The typed version was either an ordinary transcript or a transcript in one of three transcription systems used currently in research on spoken discourse, all of which incorporate notations for prosody. Hence, there were nine conditions in all, with five women and five men in each. Contrary to the experimental hypothesis, approximations to Shaw's original temporal measures of performance were not degraded but were instead improved significantly by the addition of a prosodically notated transcript to the audio recording and significantly more in the absence of the audio recording. Presentation of the ordinary transcript alone produced the worst approximation to Shaw's temporal measures. The usefulness, accuracy, and readability of transcripts prepared according to detailed notation systems are discussed.

  14. The Gaia Investigation of the Solar System

    Science.gov (United States)

    Delbo, Marco; Tanga, Paolo; Mignard, Francois; Cellino, Alberto; Hestroffer, Daniel

    2015-08-01

    The space mission Gaia of the European Space Agency (ESA) has begun its scientific whole-sky survey of all astrophysical sources with Vspectroscopy of the observed sources, including solar system small bodies. Preliminary results show a good quality of the data, in general, in line with the expected pre-flight specifications. These data will consist a mine of information for a remote-sensing exploration of the small worlds of our Solar System. Indeed, ~250,000 asteroids will be observed by Gaia throughout its 5-years-long mission. After an update about the status of the mission and the on-going data analysis, including some preliminary results, we are going to present the plans for the data releases, the first foreseen at the end of 2016, and the general data treatment.We will show how Gaia spectroscopy will allow up to map the composition of about 100,000 asteroids throughout the Main Belt, with high signal to noise ratio. Given its advantage position outside the Earth's atmosphere, the blue part of the spectrum (roughly below 0.5 micron) will be observed for an unprecedented number of asteroids.Additionally, precise photometry and astrometry will also be important to reveal the physical nature of these small bodies. In particular, it is estimated that three-dimensional shapes, rotation, period and pole orientation will be derived for 10,000 asteroids. The masses of about 150 of the largest asteroids, will be determined from measurements of the orbital gravitational perturbations that these bodies will exert on small asteroids during mutual close approaches.Moreover, the combination of Gaia data (delivering masses and shapes) with infrared radiometric observations, e.g. from the NASA WISE mission (informing us about the size of the bodies), will allow precise asteroid bulk densities to be determined. The bulk density and the internal structure are among the most important characteristics of asteroids, that are currently some of the least constrained.

  15. Mathematical System Theory and System Modeling

    OpenAIRE

    1980-01-01

    Choosing models related effectively to the questions to be addressed is a central issue in the craft of systems analysis. Since the mathematical description the analyst chooses constrains the types of issues he candeal with, it is important for these models to be selected so as to yield limitations that are acceptable in view of the questions the systems analysis seeks to answer. In this paper, the author gives an overview of the central issues affecting the question of model choice. To ...

  16. Investigation of vegetation with multifrequency and multipolarization SAR systems

    Science.gov (United States)

    Winter, Rudolf; Roth, Achim; Bayer, Thomas

    1990-05-01

    Investigations of vegetation is conducted by synergism of different types of digital image data and models. As a standard application, satellite images are digitally coregistered with existant topographical data and stored in the Geographic Information Systems (GIS). The usefulness of multiparametric SAR (Synthetic Aperture Radar) data for vegetation mapping is discussed. The multifrequency aspects requires precise geocoding. Different application fields with recent results are discussed: forest investigations with SIR (Spaceborne Imaging Radar)-B data in the southern Rhine valley ; extraction of landuse categories in landscape units using two geocoded Seasat-SAR scenes in the area of Bonn; relief effects on image gray values in geocoded Seasat-SAR images; the concept of a remote sensing data base for ecological applications.

  17. Investigation of inductively coupled ultrasonic transducer system for NDE.

    Science.gov (United States)

    Zhong, Cheng Huan; Croxford, Anthony J; Wilcox, Paul D

    2013-06-01

    Inductive coupling offers a simple solution to wirelessly probe ultrasonic transducers. This paper investigates the theory and feasibility of such an inductively coupled transducer system in the context of nondestructive evaluation (NDE) applications. The noncontact interface is based on electromagnetic coupling between three coils; one of the coils is physically connected to the transducer, the other two are in a separate probing unit, where they are connected to the transmit and receive channels of the instrumentation. The complete system is modeled as a three-port network with the measured impedance of a bonded piezoelectric ceramic disc representing a sensor attached to an arbitrary solid substrate. The developed transmission line model is a function of the physical parameters of the electromagnetic system, such as the number of turns and diameter of each coil, and their separation. This model provides immediate predictions of electrical input impedance and pulse-echo response. The model has been validated experimentally and a sensitivity analysis of the input parameters performed. This has enabled optimization of the various parameters. Inductively coupled transducer systems have been built for both bulk and guided wave examples. By using chirped excitation and baseline subtraction, inspection distance of up to 700 mm is achieved in single-shot, guided-wave pulse-echo mode measurements with a 5 mm separation between the probing coils and transducer coil on an aluminum plate structure. In the bulk wave example, a delamination in an 8.9-mm-thick carbon fiber composite specimen is successfully identified from the changes in the arrival time of a reflected pulse.

  18. An Investigation of Item Fit Statistics for Mixed IRT Models

    Science.gov (United States)

    Chon, Kyong Hee

    2009-01-01

    The purpose of this study was to investigate procedures for assessing model fit of IRT models for mixed format data. In this study, various IRT model combinations were fitted to data containing both dichotomous and polytomous item responses, and the suitability of the chosen model mixtures was evaluated based on a number of model fit procedures.…

  19. Model Reduction of Hybrid Systems

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza

    systems are derived in this thesis. The results are used for output feedback control of switched nonlinear systems. Model reduction of piecewise affine systems is also studied in this thesis. The proposed method is based on the reduction of linear subsystems inside the polytopes. The methods which......High-Technological solutions of today are characterized by complex dynamical models. A lot of these models have inherent hybrid/switching structure. Hybrid/switched systems are powerful models for distributed embedded systems design where discrete controls are applied to continuous processes...... of hybrid systems, designing controllers and implementations is very high so that the use of these models is limited in applications where the size of the state space is large. To cope with complexity, model reduction is a powerful technique. This thesis presents methods for model reduction and stability...

  20. Modeling adsorption: Investigating adsorbate and adsorbent properties

    Science.gov (United States)

    Webster, Charles Edwin

    1999-12-01

    Surface catalyzed reactions play a major role in current chemical production technology. Currently, 90% of all chemicals are produced by heterogeneously catalyzed reactions. Most of these catalyzed reactions involve adsorption, concentrating the substrate(s) (the adsorbate) on the surface of the solid (the adsorbent). Pore volumes, accessible surface areas, and the thermodynamics of adsorption are essential in the understanding of solid surface characteristics fundamental to catalyst and adsorbent screening and selection. Molecular properties such as molecular volumes and projected molecular areas are needed in order to convert moles adsorbed to surface volumes and areas. Generally, these molecular properties have been estimated from bulk properties, but many assumptions are required. As a result, different literature values are employed for these essential molecular properties. Calculated molar volumes and excluded molecular areas are determined and tabulated for a variety of molecules. Molecular dimensions of molecules are important in the understanding of molecular exclusion as well as size and shape selectivity, diffusion, and adsorbent selection. Molecular dimensions can also be used in the determination of the effective catalytic pore size of a catalyst. Adsorption isotherms, on zeolites, (crystalline mineral oxides) and amorphous solids, can be analyzed with the Multiple Equilibrium Analysis (MEA) description of adsorption. The MEA produces equilibrium constants (Ki), capacities (ni), and thermodynamic parameters (enthalpies, ΔHi, and entropies, ΔSi) of adsorption for each process. Pore volumes and accessible surface areas are calculated from the process capacities. Adsorption isotherms can also be predicted for existing and new adsorbate-adsorbent systems with the MEA. The results show that MEA has the potential of becoming a standard characterization method for microporous solids that will lead to an increased understanding of their behavior in gas

  1. Modelling on fuzzy control systems

    Institute of Scientific and Technical Information of China (English)

    LI; Hongxing(李洪兴); WANG; Jiayin(王加银); MIAO; Zhihong(苗志宏)

    2002-01-01

    A kind of modelling method for fuzzy control systems is first proposed here, which is calledmodelling method based on fuzzy inference (MMFI). It should be regarded as the third modelling method thatis different from two well-known modelling methods, that is, the first modelling method, mechanism modellingmethod (MMM), and the second modelling method, system identification modelling method (SlMM). Thismethod can, based on the interpolation mechanism on fuzzy logic system, transfer a group of fuzzy inferencerules describing a practice system into a kind of nonlinear differential equation with variable coefficients, calledHX equations, so that the mathematical model of the system can be obtained. This means that we solve thedifficult problem of how to get a model represented as differential equations on a complicated or fuzzy controlsystem.

  2. Energy System Modeling with REopt

    Energy Technology Data Exchange (ETDEWEB)

    Simpkins, Travis; Anderson, Kate; Cutler, Dylan; Olis, Dan; Elgqvist, Emma; DiOrio, Nick; Walker, Andy

    2016-07-15

    This poster details how REopt - NREL's software modeling platform for energy systems integration and optimization - can help to model energy systems. Some benefits of modeling with REopt include optimizing behind the meter storage for cost and resiliency, optimizing lab testing, optimizing dispatch of utility scale storage, and quantifying renewable energy impact on outage survivability.

  3. Amor: Investigating The Triple Asteroid System 2001 SN263

    Science.gov (United States)

    Jones, T.; Bellerose, Julie; Lee, P.; Prettyman, T.; Lawrence, D.; Smith, P.; Gaffey, M.; Nolan, M.; Goldsten, J.; Thomas, P.; Veverka, J.; Farquhar, R.; Heldmann, J.; Reddy, V.; Williams, B.; Chartres, J.; DeRosee, R.; Dunham, D.

    2010-10-01

    The Amor mission will rendezvous and land at the triple Near-Earth Asteroid system (153591) 2001 SN263 and execute detailed, in-situ science investigations. The spacecraft reaches 2001 SN263 by using a two-year ΔVEGA (ΔV-Earth Gravity Assist) trajectory with a relatively low launch C3 of 33.5 km2/s2. Rendezvous will enable reconnaissance activities including global and regional imaging, shape modeling, system dynamics, and compositional mapping. After landing, Amor will conduct in-situ imaging (panoramic to microscopic scale) and compositional measurements to include elemental abundance. The main objectives are to 1) establish in-situ the long-hypothesized link between C-type asteroids and the primitive carbonaceous chondrite (CC) meteorites, 2) investigate the nature, origin and evolution of C-type asteroids, and 3) investigate the origin and evolution of a multiple asteroid system. The mission also addresses the distribution of volatiles and organic materials, impact hazards, and resources for future exploration. Amor is managed by NASA Ames Research Center in partnership with Orbital Sciences, KinetX, MDA, and Draper with heritage instruments provided by Ball Aerospace, JHU/APL, and Firestar Engineering. The science team brings experience from NEAR, Hayabusa, Deep Impact, Dawn, LCROSS, Kepler, and Mars missions. In this paper, we describe the science, mission design, and main operational challenges of performing in-situ science at this triple asteroid system. Challenges include landing on the asteroid components, thermal environment, short day-night cycles, and the operation of deployed instruments in a low gravity (10^-5 g) environment.

  4. Reusing knowledge in embedded system modelling

    NARCIS (Netherlands)

    Marincic, J.; Mader, Angelika H.; Wieringa, Roelf J.; Lucas, Yan

    2013-01-01

    Model-based design is a promising technique to improve the quality of software and the efficiency of the software development process. We are investigating how to efficiently model embedded software and its environment to verify the requirements for the system controlled by the software. The softwar

  5. Modeling soft interface dominated systems

    NARCIS (Netherlands)

    Lamorgese, A.; Mauri, R.; Sagis, L.M.C.

    2017-01-01

    The two main continuum frameworks used for modeling the dynamics of soft multiphase systems are the Gibbs dividing surface model, and the diffuse interface model. In the former the interface is modeled as a two dimensional surface, and excess properties such as a surface density, or surface energy

  6. Validation of systems biology models

    NARCIS (Netherlands)

    Hasdemir, D.

    2015-01-01

    The paradigm shift from qualitative to quantitative analysis of biological systems brought a substantial number of modeling approaches to the stage of molecular biology research. These include but certainly are not limited to nonlinear kinetic models, static network models and models obtained by the

  7. Investigation of a Gamma model for mixture STR samples

    DEFF Research Database (Denmark)

    Christensen, Susanne; Bøttcher, Susanne Gammelgaard; Lauritzen, Steffen L.

    The behaviour of PCR Amplification Kit, when used for mixture STR samples, is investigated. A model based on the Gamma distribution is fitted to the amplifier output for constructed mixtures, and the assumptions of the model is evaluated via residual analysis.......The behaviour of PCR Amplification Kit, when used for mixture STR samples, is investigated. A model based on the Gamma distribution is fitted to the amplifier output for constructed mixtures, and the assumptions of the model is evaluated via residual analysis....

  8. Modeling of deterministic chaotic systems

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Y. [Department of Physics and Astronomy and Department of Mathematics, The University of Kansas, Lawrence, Kansas 66045 (United States); Grebogi, C. [Institute for Plasma Research, University of Maryland, College Park, Maryland 20742 (United States); Grebogi, C.; Kurths, J. [Department of Physics and Astrophysics, Universitaet Potsdam, Postfach 601553, D-14415 Potsdam (Germany)

    1999-03-01

    The success of deterministic modeling of a physical system relies on whether the solution of the model would approximate the dynamics of the actual system. When the system is chaotic, situations can arise where periodic orbits embedded in the chaotic set have distinct number of unstable directions and, as a consequence, no model of the system produces reasonably long trajectories that are realized by nature. We argue and present physical examples indicating that, in such a case, though the model is deterministic and low dimensional, statistical quantities can still be reliably computed. {copyright} {ital 1999} {ital The American Physical Society}

  9. Human performance modeling for system of systems analytics.

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Kevin R.; Lawton, Craig R.; Basilico, Justin Derrick; Longsine, Dennis E. (INTERA, Inc., Austin, TX); Forsythe, James Chris; Gauthier, John Henry; Le, Hai D.

    2008-10-01

    A Laboratory-Directed Research and Development project was initiated in 2005 to investigate Human Performance Modeling in a System of Systems analytic environment. SAND2006-6569 and SAND2006-7911 document interim results from this effort; this report documents the final results. The problem is difficult because of the number of humans involved in a System of Systems environment and the generally poorly defined nature of the tasks that each human must perform. A two-pronged strategy was followed: one prong was to develop human models using a probability-based method similar to that first developed for relatively well-understood probability based performance modeling; another prong was to investigate more state-of-art human cognition models. The probability-based modeling resulted in a comprehensive addition of human-modeling capability to the existing SoSAT computer program. The cognitive modeling resulted in an increased understanding of what is necessary to incorporate cognition-based models to a System of Systems analytic environment.

  10. Modelling of wastewater systems

    DEFF Research Database (Denmark)

    Bechmann, Henrik

    In this thesis, models of pollution fluxes in the inlet to 2 Danish wastewater treatment plants (WWTPs) as well as of suspended solids (SS) concentrations in the aeration tanks of an alternating WWTP and in the effluent from the aeration tanks are developed. The latter model is furthermore used...

  11. Modelling Epistemic Systems

    CERN Document Server

    Martins, Andre C R

    2012-01-01

    In this Chapter, I will explore the use of modeling in order to understand how Science works. I will discuss the modeling of scientific communities, providing a general, non-comprehensive overview of existing models, with a focus on the use of the tools of Agent-Based Modeling and Opinion Dynamics. A special attention will be paid to models inspired by a Bayesian formalism of Opinion Dynamics. The objective of this exploration is to better understand the effect that different conditions might have on the reliability of the opinions of a scientific community. We will see that, by using artificial worlds as exploring grounds, we can prevent some epistemological problems with the definition of truth and obtain insights on the conditions that might cause the quest for more reliable knowledge to fail.

  12. From Numeric Models to Granular System Modeling

    Directory of Open Access Journals (Sweden)

    Witold Pedrycz

    2015-03-01

    To make this study self-contained, we briefly recall the key concepts of granular computing and demonstrate how this conceptual framework and its algorithmic fundamentals give rise to granular models. We discuss several representative formal setups used in describing and processing information granules including fuzzy sets, rough sets, and interval calculus. Key architectures of models dwell upon relationships among information granules. We demonstrate how information granularity and its optimization can be regarded as an important design asset to be exploited in system modeling and giving rise to granular models. With this regard, an important category of rule-based models along with their granular enrichments is studied in detail.

  13. A Simulation Base Investigation of High Latency Space Systems Operations

    Science.gov (United States)

    Li, Zu Qun; Crues, Edwin Z.; Bielski, Paul; Moore, Michael

    2017-01-01

    NASA's human space program has developed considerable experience with near Earth space operations. Although NASA has experience with deep space robotic missions, NASA has little substantive experience with human deep space operations. Even in the Apollo program, the missions lasted only a few weeks and the communication latencies were on the order of seconds. Human missions beyond the relatively close confines of the Earth-Moon system will involve missions with durations measured in months and communications latencies measured in minutes. To minimize crew risk and to maximize mission success, NASA needs to develop a better understanding of the implications of these types of mission durations and communication latencies on vehicle design, mission design and flight controller interaction with the crew. To begin to address these needs, NASA performed a study using a physics-based subsystem simulation to investigate the interactions between spacecraft crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation, built with a subsystem modeling tool developed at NASA's Johnson Space Center, models the life support system of a Mars transit vehicle. The simulation contains models of the cabin atmosphere and pressure control system, electrical power system, drinking and waste water systems, internal and external thermal control systems, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the vehicle subsystems; 2) a mission control center interface with data transport delays up to 15 minutes each way; 3) a real-time simulation test conductor interface that can be use to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission between July 18th and Aug 3rd of year 2016. The NEEMO

  14. Pluralistic Modeling of Complex Systems

    CERN Document Server

    Helbing, Dirk

    2010-01-01

    The modeling of complex systems such as ecological or socio-economic systems can be very challenging. Although various modeling approaches exist, they are generally not compatible and mutually consistent, and empirical data often do not allow one to decide what model is the right one, the best one, or most appropriate one. Moreover, as the recent financial and economic crisis shows, relying on a single, idealized model can be very costly. This contribution tries to shed new light on problems that arise when complex systems are modeled. While the arguments can be transferred to many different systems, the related scientific challenges are illustrated for social, economic, and traffic systems. The contribution discusses issues that are sometimes overlooked and tries to overcome some frequent misunderstandings and controversies of the past. At the same time, it is highlighted how some long-standing scientific puzzles may be solved by considering non-linear models of heterogeneous agents with spatio-temporal inte...

  15. Quantum chemistry investigation of fluorinated polymer systems of industrial interest.

    Science.gov (United States)

    Mavroudakis, Evangelos; Cuccato, Danilo; Dossi, Marco; Comino, Giovanni; Moscatelli, Davide

    2014-01-09

    In this work, the free-radical polymerization (FRP) of widely used fluorinated monomers was investigated. Computational studies were conducted to assess the FRP kinetics of each binary copolymerization between vinylidene fluoride (VDF), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE). More specifically, all calculations were performed using density functional theory (DFT), and the B3LYP level of theory was used to optimize structures and determine absolute minimum energy geometries, whereas the electronic energies were estimated using B3LYP/6-31G(d,p) as well as a higher level of theory, MPWB1K/6-31G(d,p). Transition state theory was employed to determine kinetic parameters according to the terminal model of copolymerization. The homopolymerization of VDF and all of its corresponding copolymerizations were investigated by taking into account every possible propagation reaction (head to head, head to tail, tail to tail, head to monomer, tail to monomer, etc.) to estimate the Arrhenius parameters for each system. This study provides the estimation of a large set of rate coefficients, which gives detailed pictures of the specific copolymerization systems examined and is highly valuable to generate a comprehensive overview of the polymerization kinetics of relevant fluorinated monomers.

  16. Simulated, Emulated, and Physical Investigative Analysis (SEPIA) of networked systems.

    Energy Technology Data Exchange (ETDEWEB)

    Burton, David P.; Van Leeuwen, Brian P.; McDonald, Michael James; Onunkwo, Uzoma A.; Tarman, Thomas David; Urias, Vincent E.

    2009-09-01

    This report describes recent progress made in developing and utilizing hybrid Simulated, Emulated, and Physical Investigative Analysis (SEPIA) environments. Many organizations require advanced tools to analyze their information system's security, reliability, and resilience against cyber attack. Today's security analysis utilize real systems such as computers, network routers and other network equipment, computer emulations (e.g., virtual machines) and simulation models separately to analyze interplay between threats and safeguards. In contrast, this work developed new methods to combine these three approaches to provide integrated hybrid SEPIA environments. Our SEPIA environments enable an analyst to rapidly configure hybrid environments to pass network traffic and perform, from the outside, like real networks. This provides higher fidelity representations of key network nodes while still leveraging the scalability and cost advantages of simulation tools. The result is to rapidly produce large yet relatively low-cost multi-fidelity SEPIA networks of computers and routers that let analysts quickly investigate threats and test protection approaches.

  17. Investigations of Intelligent Solar Heating Systems for Single Family House

    DEFF Research Database (Denmark)

    Andersen, Elsa; Chen, Ziqian; Fan, Jianhua

    2014-01-01

    systems.The system will be equipped with an intelligent control system where the control of the electrical heating element(s)/heat pump is based on forecasts of the variable electricity price, the heating demand and the solar energy production.By means of numerical models of the systems made in Trnsys...

  18. Integrated Modeling Systems

    Science.gov (United States)

    1989-01-01

    American Economic Review , 71:1 (March 1981). 181 J.M. Jones and F. Zufryden. "Adding Explanatory Variables to a Consumer Purchase Behavior Model: An...McCall. "An Operational Measure of Liquidity," The American Economic Review , 761 (March 1986). WMSI Working Paper 329. 212 Nelson, R., R. Sarin, and R

  19. Robust Disaster Recovery System Model

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Highly security-critical system should possess features of continuous service. We present a new Robust Disaster Recovery System Model (RDRSM). Through strengthening the ability of safe communications, RDRSM guarantees the secure and reliable command on disaster recovery. Its self-supervision capability can monitor the integrality and security of disaster recovery system itself. By 2D and 3D real-time visible platform provided by GIS, GPS and RS, the model makes the using, management and maintenance of disaster recovery system easier. RDRSM possesses predominant features of security, robustness and controllability. And it can be applied to highly security-critical environments such as E-government and bank. Conducted by RDRSM, an important E-government disaster recovery system has been constructed successfully. The feasibility of this model is verified by practice. We especially emphasize the significance of some components of the model, such as risk assessment, disaster recovery planning, system supervision and robust communication support.

  20. Simulation Model of Brushless Excitation System

    Directory of Open Access Journals (Sweden)

    Ahmed N.A.  Alla

    2007-01-01

    Full Text Available Excitation system is key element in the dynamic performance of electric power systems, accurate excitation models are of great importance in simulating and investigating the power system transient phenomena. Parameter identification of the Brushless excitation system was presented. First a block diagram for the EXS parameter was proposed based on the documents and maps in the power station. To identify the parameters of this model, a test procedure to obtain step response, was presented. Using the Genetic Algorithm with the Matlab-software it was possible to identify all the necessary parameters of the model. Using the same measured input signals the response from the standard model showed nearly the same behavior as the excitation system.

  1. An Exploratory Investigation on the Invasiveness of Environmental Modeling Frameworks

    Science.gov (United States)

    This paper provides initial results of an exploratory investigation on the invasiveness of environmental modeling frameworks. Invasiveness is defined as the coupling between application (i.e., model) and framework code used to implement the model. By comparing the implementation of an environmenta...

  2. Mechanical Systems, Classical Models

    CERN Document Server

    Teodorescu, Petre P

    2007-01-01

    All phenomena in nature are characterized by motion; this is an essential property of matter, having infinitely many aspects. Motion can be mechanical, physical, chemical or biological, leading to various sciences of nature, mechanics being one of them. Mechanics deals with the objective laws of mechanical motion of bodies, the simplest form of motion. In the study of a science of nature mathematics plays an important role. Mechanics is the first science of nature which was expressed in terms of mathematics by considering various mathematical models, associated to phenomena of the surrounding nature. Thus, its development was influenced by the use of a strong mathematical tool; on the other hand, we must observe that mechanics also influenced the introduction and the development of many mathematical notions. In this respect, the guideline of the present book is precisely the mathematical model of mechanics. A special accent is put on the solving methodology as well as on the mathematical tools used; vectors, ...

  3. Investigating the Propagation of Meteorological Model Uncertainty for Tracer Modeling

    Science.gov (United States)

    Lopez-Coto, I.; Ghosh, S.; Karion, A.; Martin, C.; Mueller, K. L.; Prasad, K.; Whetstone, J. R.

    2016-12-01

    The North-East Corridor project aims to use a top-down inversion method to quantify sources of Greenhouse Gas (GHG) emissions in the urban areas of Washington DC and Baltimore at approximately 1km2 resolutions. The aim of this project is to help establish reliable measurement methods for quantifying and validating GHG emissions independently of the inventory methods typically used to guide mitigation efforts. Since inversion methods depend strongly on atmospheric transport modeling, analyzing the uncertainties on the meteorological fields and their propagation through the sensitivities of observations to surface fluxes (footprints) is a fundamental step. To this end, six configurations of the Weather Research and Forecasting Model (WRF-ARW) version 3.8 were used to generate an ensemble of meteorological simulations. Specifically, we used 4 planetary boundary layer parameterizations (YSU, MYNN2, BOULAC, QNSE), 2 sources of initial and boundary conditions (NARR and HRRR) and 1 configuration including the building energy parameterization (BEP) urban canopy model. The simulations were compared with more than 150 meteorological surface stations, a wind profiler and radiosondes for a month (February) in 2016 to account for the uncertainties and the ensemble spread for wind speed, direction and mixing height. In addition, we used the Stochastic Time-Inverted Lagrangian Transport model (STILT) to derive the sensitivity of 12 hypothetical observations to surface emissions (footprints) with each WRF configuration. The footprints and integrated sensitivities were compared and the resulting uncertainties estimated.

  4. Relocatable Coastal Modeling System

    Science.gov (United States)

    2016-06-07

    These relationships are stored on a variable-resolution grid (illustrated in figure 1b below) with sampling of 1 degree in deep water (and in data...version is referred to as MODAS2.1, which is now operational at NAVO. The NOMADS interface is being replaced by a system-independent, web -based version...inside the user’s web browser plus Perl CGI scripts which ran on a webserver. This permitted the user to run MODAS (and POM and other modules as they are

  5. Hydronic distribution system computer model

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, J.W.; Strasser, J.J.

    1994-10-01

    A computer model of a hot-water boiler and its associated hydronic thermal distribution loop has been developed at Brookhaven National Laboratory (BNL). It is intended to be incorporated as a submodel in a comprehensive model of residential-scale thermal distribution systems developed at Lawrence Berkeley. This will give the combined model the capability of modeling forced-air and hydronic distribution systems in the same house using the same supporting software. This report describes the development of the BNL hydronics model, initial results and internal consistency checks, and its intended relationship to the LBL model. A method of interacting with the LBL model that does not require physical integration of the two codes is described. This will provide capability now, with reduced up-front cost, as long as the number of runs required is not large.

  6. Data management system performance modeling

    Science.gov (United States)

    Kiser, Larry M.

    1993-01-01

    This paper discusses analytical techniques that have been used to gain a better understanding of the Space Station Freedom's (SSF's) Data Management System (DMS). The DMS is a complex, distributed, real-time computer system that has been redesigned numerous times. The implications of these redesigns have not been fully analyzed. This paper discusses the advantages and disadvantages for static analytical techniques such as Rate Monotonic Analysis (RMA) and also provides a rationale for dynamic modeling. Factors such as system architecture, processor utilization, bus architecture, queuing, etc. are well suited for analysis with a dynamic model. The significance of performance measures for a real-time system are discussed.

  7. Investigation of the Physics of Flocculation in Algal Systems

    Science.gov (United States)

    Pierce, Flint; Lechman, Jeremy; Hewson, John

    2012-02-01

    Algae biofuel production has gained a great deal of interest in recent years due to the high photosynthetic efficiency of various algae strains and the ability of stressed algae populations to produce large quantities of lipids within their cells. Separation of the algae from the background aqueous medium engenders large energetic costs for standard separation techniques including filtration, centrifugation, and dissolved air flotation since algae cells are small (microns to 10s of microns), have densities similar to the surrounding fluid, and normally occur at low volume fractions (1E-4 -> 1E-3). Flocculation is one possible route to reducing the cost of collecting the algae biomass, since large algae flocs can easily be removed from the aqueous environment through either differential settling or standard filtration. To this end, We model flocculating systems of algae cells using discrete particle dynamics techniques which incorporate a recently developed adhesive granular potential to govern the cell interactions. This potential is shown to reproduce morphological characteristics, kinetics, and size distributions that agree well with known results for flocculation in the diffusive regime (DLCA). We further investigate flocculation under steady shear and compare our results to both experiment and predictions from various orthokinetic models.

  8. Investigation in Query System Framework for High Energy Physics

    CERN Document Server

    Jatuphattharachat, Thanat

    2017-01-01

    We summarize an investigation in query system framework for HEP (High Energy Physics). Our work was an investigation on distributed server part of Femtocode, which is a query language that provides the ability for physicists to make plots and other aggregations in real-time. To make the system more robust and capable of processing large amount of data quickly, it is necessary to deploy the system on a redundant and distributed computing cluster. This project aims to investigate third party coordination and resource management frameworks which fit into the design of real-time distributed query system. Zookeeper, Mesos and Marathon are the main frameworks for this investigation. The results indicate that Zookeeper is good for job coordinator and job tracking as it provides robust, fast, simple and transparent read and write process for all connecting client across distributed Zookeeper server. Furthermore, it also supports high availability access and consistency guarantee within specific time bound.

  9. The development of a theoretical model to investigate factors ...

    African Journals Online (AJOL)

    The development of a theoretical model to investigate factors associated with ... major household appliance market: An integrative conceptual approach. ... disadvantaged consumers gain spending power and access to electricity supply.

  10. Investigation of the stability of melt flow in gating systems

    DEFF Research Database (Denmark)

    Tiedje, Niels Skat; Larsen, Per

    2011-01-01

    of the gating system causes pressure waves to form that eventually lead to defective castings. It is clear that sharp corners and dead ends in gating systems should be avoided, and that more stream lined, organic designs based on fluid dynamic principles will are necessary to design gating systems......Melt flow in four different gating systems designed for production of brake discs was analysed experimentally and by numerical modelling. In the experiments moulds were fitted with glass fronts and melt flow was recorded on video. The video recordings were compared with modelling of melt flow...... in the gating systems. Particular emphasis was on analysing local pressure and formation of pressure waves in the gating system. It was possible to compare melt flow patterns in experiments directly to modelled flow patterns. Generally there was good agreement between flow patterns and filling times. However...

  11. [Investigation of transitions from order to chaos in dynamical systems

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    This report briefly discusses the following topics on chaotic systems; numerical investigations of fast dynamo problem for stationary space-periodic flows with chaotic streamlines; analytical and numerical investigations of magnetic field generation by conducting flows with finite resistivity; and emittance growth in charged particle beams.

  12. Low Frequency Radio-wave System for subsurface investigation

    Science.gov (United States)

    Soldovieri, Francesco; Gennarelli, Gianluca; Kudelya, Anatoliy; Denisov, Alexander

    2015-04-01

    Low frequency radio-wave methods (RWM) allow subsurface investigations in terms of lithological structure characterization, detection of filtration flows of ground water, anthropogenic and natural cavities. In this contribution, we present a RWM that exploits two coils working at frequencies of few MHz as transmitting and receiving antennas. The basic principle of this inductive method is as follows. The primary alternating electromagnetic field radiated by the transmitting coil induces eddy currents in the subsurface mainly due to the conductivity anomalies. These eddy currents generate a secondary (scattered) magnetic field which overlaps to the incident magnetic field and is detected by the receiving coil. Despite the simple operation of the system, the complexity of the electromagnetic scattering phenomenon at hand must be properly modeled to achieve adequate performance. Therefore, an advanced data processing technique, belonging to the class of the inverse scattering approaches, has been developed by the authors in a full 3D geometry. The proposed method allows to deal with data collected on a scanning surface under a dipole inductive profiling (DIP) modality, where the transmitting/receiving coils are moved simultaneously with fixed offset (multi-bistatic configuration). The hardware, called Dipole Inductive Radio-wave System (DIRS), is composed by an electronic unit and transmitting and receiving loop antennas radiating at frequencies of few MHz (2-4 MHz), which are installed on theodolite supports. The compactness of DIRS and its robustness to external electromagnetic interference offers the possibility to perform geophysical research up to the depth of some tens of meters and under several types of ground and water surfaces, vegetation, and weather conditions. The light weight and small size of system (the single antenna with support weights about 5 kg and has a diameter of 0.5m) allows two operators to perform geophysical research without disturbing the

  13. National Energy Outlook Modelling System

    Energy Technology Data Exchange (ETDEWEB)

    Volkers, C.M. [ECN Policy Studies, Petten (Netherlands)

    2013-12-15

    For over 20 years, the Energy research Centre of the Netherlands (ECN) has been developing the National Energy Outlook Modelling System (NEOMS) for Energy projections and policy evaluations. NEOMS enables 12 energy models of ECN to exchange data and produce consistent and detailed results.

  14. ABSTRACT MODELS FOR SYSTEM VIRTUALIZATION

    Directory of Open Access Journals (Sweden)

    M. G. Koveshnikov

    2015-05-01

    Full Text Available The paper is dedicated to issues of system objects securing (system files and user system or application configuration files against unauthorized access including denial of service attacks. We have suggested the method and developed abstract system virtualization models, which are used toresearch attack scenarios for different virtualization modes. Estimation for system tools virtualization technology effectiveness is given. Suggested technology is based on redirection of access requests to system objects shared among access subjects. Whole and partial system virtualization modes have been modeled. The difference between them is the following: in the whole virtualization mode all copies of access system objects are created whereon subjects’ requests are redirected including corresponding application objects;in the partial virtualization mode corresponding copies are created only for part of a system, for example, only system objects for applications. Alternative solutions effectiveness is valued relating to different attack scenarios. We consider proprietary and approved technical solution which implements system virtualization method for Microsoft Windows OS family. Administrative simplicity and capabilities of correspondingly designed system objects security tools are illustrated on this example. Practical significance of the suggested security method has been confirmed.

  15. A descriptive ecosystem model - a strategy for model development during site investigations

    Energy Technology Data Exchange (ETDEWEB)

    Loefgren, Anders [Stockholm Univ. (Sweden). Dept. of Botany; Lindborg, Tobias [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2003-09-01

    This report describes a strategy for the development of a site descriptive model for the surface ecosystem on the potential deep repository sites. The surface ecosystem embraces many disciplines, and these have to be identified, described and integrated in order to construct a descriptive ecosystem model that describes and quantifies biotic and abiotic patterns and processes of importance for the ecosystem on the site. The descriptive model includes both present day conditions and historical information. The descriptive ecosystem model will be used to supply input data for the safety assessment and to serve as the baseline model for devising a monitoring program to detect short-term disturbances caused first by the site investigations and later by the construction of the deep repository. Furthermore, it will serve as a reference for future comparisons to determine more long-term effects or changes caused by the deep repository. The report adopts a non-site-specific approach focusing on the following aims: 1. To present and define the properties that will constitute the descriptive ecosystem model. 2. To present a methodology for determining those properties. 3. To describe and develop the framework for the descriptive ecosystem model by integrating the different properties. 4. To present vital data from other site descriptive models such as those for geology or hydrogeology that interacts with and affects the descriptive ecosystem model. The properties are described under four different sections: general physical properties of the landscape, the terrestrial system, the limnic system and the marine system. These headings are further subdivided into entities that integrate properties in relation to processes.

  16. Experimental Modeling of Dynamic Systems

    DEFF Research Database (Denmark)

    Knudsen, Morten Haack

    2006-01-01

    An engineering course, Simulation and Experimental Modeling, has been developed that is based on a method for direct estimation of physical parameters in dynamic systems. Compared with classical system identification, the method appears to be easier to understand, apply, and combine with physical...

  17. Investigation of the Bruce B delayed neutron detection system

    Energy Technology Data Exchange (ETDEWEB)

    Carriere, O. [Univ. of Ottawa, Ottawa, Ontario (Canada)

    2003-08-01

    The present goal of this investigation is to improve the sensitivity of the Delayed Neutron Detector System. The sensitivity of the system is not as good as requested. A software upgrade if possible will be more favorable than a hardware upgrade because of the possible cost implied. (author)

  18. Investigating the LGBTQ Responsive Model for Supervision of Group Work

    Science.gov (United States)

    Luke, Melissa; Goodrich, Kristopher M.

    2013-01-01

    This article reports an investigation of the LGBTQ Responsive Model for Supervision of Group Work, a trans-theoretical supervisory framework to address the needs of lesbian, gay, bisexual, transgender, and questioning (LGBTQ) persons (Goodrich & Luke, 2011). Findings partially supported applicability of the LGBTQ Responsive Model for Supervision…

  19. Investigating the LGBTQ Responsive Model for Supervision of Group Work

    Science.gov (United States)

    Luke, Melissa; Goodrich, Kristopher M.

    2013-01-01

    This article reports an investigation of the LGBTQ Responsive Model for Supervision of Group Work, a trans-theoretical supervisory framework to address the needs of lesbian, gay, bisexual, transgender, and questioning (LGBTQ) persons (Goodrich & Luke, 2011). Findings partially supported applicability of the LGBTQ Responsive Model for Supervision…

  20. Investigation of air cleaning system response to accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Andrae, R.W.; Bolstad, J.W.; Foster, R.D.; Gregory, W.S.; Horak, H.L.; Idar, E.S.; Martin, R.A.; Ricketts, C.I.; Smith, P.R.; Tang, P.K.

    1980-01-01

    Air cleaning system response to the stress of accident conditions are being investigated. A program overview and hghlight recent results of our investigation are presented. The program includes both analytical and experimental investigations. Computer codes for predicting effects of tornados, explosions, fires, and material transport are described. The test facilities used to obtain supportive experimental data to define structural integrity and confinement effectiveness of ventilation system components are described. Examples of experimental results for code verification, blower response to tornado transients, and filter response to tornado and explosion transients are reported.

  1. An extensible analysable system model

    DEFF Research Database (Denmark)

    Probst, Christian W.; Hansen, Rene Rydhof

    2008-01-01

    , this does not hold for real physical systems. Approaches such as threat modelling try to target the formalisation of the real-world domain, but still are far from the rigid techniques available in security research. Many currently available approaches to assurance of critical infrastructure security...... allows for easy development of analyses for the abstracted systems. We briefly present one application of our approach, namely the analysis of systems for potential insider threats....

  2. CTBT integrated verification system evaluation model supplement

    Energy Technology Data Exchange (ETDEWEB)

    EDENBURN,MICHAEL W.; BUNTING,MARCUS; PAYNE JR.,ARTHUR C.; TROST,LAWRENCE C.

    2000-03-02

    Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia's Monitoring Systems and Technology Center and has been funded by the U.S. Department of Energy's Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, ''top-level,'' modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM's unique features is that it integrates results from the various CTBT sensor technologies (seismic, in sound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection), location accuracy, and identification capability of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system's performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. The original IVSEM report, CTBT Integrated Verification System Evaluation Model, SAND97-25 18, described version 1.2 of IVSEM. This report describes the changes made to IVSEM version 1.2 and the addition of identification capability estimates that have been incorporated into IVSEM version 2.0.

  3. CTBT integrated verification system evaluation model supplement

    Energy Technology Data Exchange (ETDEWEB)

    EDENBURN,MICHAEL W.; BUNTING,MARCUS; PAYNE JR.,ARTHUR C.; TROST,LAWRENCE C.

    2000-03-02

    Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia's Monitoring Systems and Technology Center and has been funded by the U.S. Department of Energy's Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, ''top-level,'' modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM's unique features is that it integrates results from the various CTBT sensor technologies (seismic, in sound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection), location accuracy, and identification capability of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system's performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. The original IVSEM report, CTBT Integrated Verification System Evaluation Model, SAND97-25 18, described version 1.2 of IVSEM. This report describes the changes made to IVSEM version 1.2 and the addition of identification capability estimates that have been incorporated into IVSEM version 2.0.

  4. Expert Systems as a Mindtool To Facilitate Mental Model Learning.

    Science.gov (United States)

    Mason-Mason, Susan Dale; Tessmer, Martin A.

    2000-01-01

    This exploratory study investigated whether the process of constructing an expert system model promotes the formation of expert-like mental models. Discusses expert systems as mindtools, expert systems as learning tools, the assessment of mental models, results of pretests and posttests, and future research. (Contains 56 references.) (Author/LRW)

  5. Modeling Multi-Level Systems

    CERN Document Server

    Iordache, Octavian

    2011-01-01

    This book is devoted to modeling of multi-level complex systems, a challenging domain for engineers, researchers and entrepreneurs, confronted with the transition from learning and adaptability to evolvability and autonomy for technologies, devices and problem solving methods. Chapter 1 introduces the multi-scale and multi-level systems and highlights their presence in different domains of science and technology. Methodologies as, random systems, non-Archimedean analysis, category theory and specific techniques as model categorification and integrative closure, are presented in chapter 2. Chapters 3 and 4 describe polystochastic models, PSM, and their developments. Categorical formulation of integrative closure offers the general PSM framework which serves as a flexible guideline for a large variety of multi-level modeling problems. Focusing on chemical engineering, pharmaceutical and environmental case studies, the chapters 5 to 8 analyze mixing, turbulent dispersion and entropy production for multi-scale sy...

  6. Modelling and control of a suspension system for vehicle applications

    OpenAIRE

    Dowds, Padraig; O'Dwyer, Aidan

    2005-01-01

    This paper discusses the modelling of passive and active suspension systems in a car, and the subsequent design of appropriate feedback controllers for the active suspension system. The models will be investigated using a quarter car model and a full car model approach.

  7. Integrating Building Information Modeling and Augmented Reality to Improve Investigation of Historical Buildings

    Directory of Open Access Journals (Sweden)

    Francesco Chionna

    2015-12-01

    Full Text Available This paper describes an experimental system to support investigation of historical buildings using Building Information Modeling (BIM and Augmented Reality (AR. The system requires the use of an off-line software to build the BIM representation and defines a method to integrate diagnostic data into BIM. The system offers access to such information during site investigation using AR glasses supported by marker and marker-less technologies. The main innovation is the possibility to contextualize through AR not only existing BIM properties but also results from non-invasive tools. User evaluations show how the use of the system may enhance the perception of engineers during the investigation process.

  8. An Investigation of Model Catalyzed Hydrocarbon Formation Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Tysoe, W. T.

    2001-05-02

    Work was focused on two areas aimed at understanding the chemistry of realistic catalytic systems: (1) The synthesis and characterization of model supported olefin metathesis catalysts. (2) Understanding the role of the carbonaceous layer present on Pd(111) single crystal model catalysts during reaction.

  9. Distribution system modeling and analysis

    CERN Document Server

    Kersting, William H

    2002-01-01

    For decades, distribution engineers did not have the sophisticated tools developed for analyzing transmission systems-often they had only their instincts. Things have changed, and we now have computer programs that allow engineers to simulate, analyze, and optimize distribution systems. Powerful as these programs are, however, without a real understanding of the operating characteristics of a distribution system, engineers using the programs can easily make serious errors in their designs and operating procedures.Distribution System Modeling and Analysis helps prevent those errors. It gives re

  10. Investigation on energy efficient sensor node placement in railway systems

    Directory of Open Access Journals (Sweden)

    Ayona Philipose

    2016-06-01

    Full Text Available Recently wireless sensor network (WSN has been widely used for monitoring railway tracks and rail tunnels. The key requirement in the design of such WSN is to minimize the energy consumption so as to maximize the network lifetime. This paper includes the performance of an improved medium access control (MAC protocol, namely, time adaptive-bit map assisted (TA-BMA protocol, for the purpose of communication between the sensors placed in a railway wagon. The train is considered to be moving at a constant speed, and the sensor nodes are stationary with respect to the motion of train. The effect of mobility on the proposed MAC protocol is determined using genetic algorithm (GA, and the observed increase in energy consumption on considering mobility is 18.51%. Performance analysis of the system model is carried out using QualNet (ver. 7.1, and the energy consumption in transmit mode, receive mode, percentage of time in sleep mode, end-to-end delay and throughput are investigated.

  11. Compact turnkey focussing neutron guide system for inelastic scattering investigations

    Energy Technology Data Exchange (ETDEWEB)

    Brandl, G., E-mail: g.brandl@fz-juelich.de [Heinz Maier-Leibnitz Zentrum (MLZ) and Physik Department E21, Technische Universität München, 85748 Garching, Germany and Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum - MLZ, Forschungszentrum Jülich GmbH, 85748 Garching (Germany); Georgii, R. [Heinz Maier-Leibnitz Zentrum (MLZ) and Physik Department E21, Technische Universität München, 85748 Garching (Germany); Dunsiger, S. R. [Physik Department E21, Technische Universität München, 85748 Garching, Germany and Center for Emergent Materials, Ohio State University, Columbus, Ohio 43210-1117 (United States); Tsurkan, V. [Experimental Physics V, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, 86159 Augsburg, Germany and Institute of Applied Physics, Academy of Sciences of Moldova, MD 2028 Chisinau, Republic of Moldova (Germany); Loidl, A. [Experimental Physics V, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, 86159 Augsburg (Germany); Adams, T.; Pfleiderer, C.; Böni, P. [Physik Department E21, Technische Universität München, 85748 Garching (Germany)

    2015-12-21

    We demonstrate the performance of a compact neutron guide module which boosts the intensity in inelastic neutron scattering experiments by approximately a factor of 40. The module consists of two housings containing truly curved elliptic focussing guide elements, positioned before and after the sample. The advantage of the module lies in the ease with which it may be reproducibly mounted on a spectrometer within a few hours, on the same timescale as conventional sample environments. It is particularly well suited for samples with a volume of a few mm{sup 3}, thus enabling the investigation of materials which to date would have been considered prohibitively small or samples exposed to extreme environments, where there are space constraints. We benchmark the excellent performance of the module by measurements of the structural and magnetic excitations in single crystals of model systems. In particular, we report the phonon dispersion in the simple element lead. We also determine the magnon dispersion in the spinel ZnCr{sub 2}Se{sub 4} (V = 12.5 mm{sup 3}), where strong magnetic diffuse scattering at low temperatures evolves into distinct helical order.

  12. Compact turnkey focussing neutron guide system for inelastic scattering investigations

    Science.gov (United States)

    Brandl, G.; Georgii, R.; Dunsiger, S. R.; Tsurkan, V.; Loidl, A.; Adams, T.; Pfleiderer, C.; Böni, P.

    2015-12-01

    We demonstrate the performance of a compact neutron guide module which boosts the intensity in inelastic neutron scattering experiments by approximately a factor of 40. The module consists of two housings containing truly curved elliptic focussing guide elements, positioned before and after the sample. The advantage of the module lies in the ease with which it may be reproducibly mounted on a spectrometer within a few hours, on the same timescale as conventional sample environments. It is particularly well suited for samples with a volume of a few mm3, thus enabling the investigation of materials which to date would have been considered prohibitively small or samples exposed to extreme environments, where there are space constraints. We benchmark the excellent performance of the module by measurements of the structural and magnetic excitations in single crystals of model systems. In particular, we report the phonon dispersion in the simple element lead. We also determine the magnon dispersion in the spinel ZnCr2Se4 (V = 12.5 mm3), where strong magnetic diffuse scattering at low temperatures evolves into distinct helical order.

  13. Stirling Engine Dynamic System Modeling

    Science.gov (United States)

    Nakis, Christopher G.

    2004-01-01

    The Thermo-Mechanical systems branch at the Glenn Research Center focuses a large amount time on Stirling engines. These engines will be used on missions where solar power is inefficient, especially in deep space. I work with Tim Regan and Ed Lewandowski who are currently developing and validating a mathematical model for the Stirling engines. This model incorporates all aspects of the system including, mechanical, electrical and thermodynamic components. Modeling is done through Simplorer, a program capable of running simulations of the model. Once created and then proven to be accurate, a model is used for developing new ideas for engine design. My largest specific project involves varying key parameters in the model and quantifying the results. This can all be done relatively trouble-free with the help of Simplorer. Once the model is complete, Simplorer will do all the necessary calculations. The more complicated part of this project is determining which parameters to vary. Finding key parameters depends on the potential for a value to be independently altered in the design. For example, a change in one dimension may lead to a proportional change to the rest of the model, and no real progress is made. Also, the ability for a changed value to have a substantial impact on the outputs of the system is important. Results will be condensed into graphs and tables with the purpose of better communication and understanding of the data. With the changing of these parameters, a more optimal design can be created without having to purchase or build any models. Also, hours and hours of results can be simulated in minutes. In the long run, using mathematical models can save time and money. Along with this project, I have many other smaller assignments throughout the summer. My main goal is to assist in the processes of model development, validation and testing.

  14. Calibration and investigation of infrared camera systems applying blackbody radiation

    Science.gov (United States)

    Hartmann, Juergen; Fischer, Joachim

    2001-03-01

    An experimental facility is presented, which allows calibration and detailed investigation of infrared camera systems. Various blackbodies operating in the temperature range from -60 degree(s)C up to 3000 degree(s)C serve as standard radiation sources, enabling calibration of camera systems in a wide temperature and spectral range with highest accuracy. Quantitative results and precise long-term investigations, especially in detecting climatic trends, require accurate traceability to the International Temperature Scale of 1990 (ITS-90). For the used blackbodies the traceability to ITS- 90 is either realized by standard platinum resistance thermometers (in the temperature range below 962 degree(s)C) or by absolute and relative radiometry (in the temperature range above 962 degree(s)C). This traceability is fundamental for implementation of quality assurance systems and realization of different standardizations, for example according ISO 9000. For investigation of the angular and the temperature resolution our set-up enables minimum resolvable (MRTD) and minimum detectable temperature difference (MDTD) measurements in the various temperature ranges. A collimator system may be used to image the MRTD and MDTD targets to infinity. As internal calibration of infrared camera systems critically depends on the temperature of the surrounding, the calibration and investigation of the cameras is performed in a climate box, which allows a detailed controlling of the environmental parameters like humidity and temperature. Experimental results obtained for different camera systems are presented and discussed.

  15. Statistics-based investigation on typhoon transition modeling

    DEFF Research Database (Denmark)

    Zhang, Shuoyun; Nishijima, Kazuyoshi

    and the seasonality are taken into account by developing the models for different spatial grids and seasons separately. An appropriate size of spatial grids is investigated. The statistical characteristics of the random residual terms in the models are also examined. Finally, Monte Carlo simulations are performed......The present study revisits the statistical modeling of typhoon transition. The objective of the study is to provide insights on plausible statistical typhoon transition models based on extensive statistical analysis. First, the correlation structures of the typhoon transition are estimated in terms...

  16. Trends in modeling Biomedical Complex Systems

    Directory of Open Access Journals (Sweden)

    Remondini Daniel

    2009-10-01

    Full Text Available Abstract In this paper we provide an introduction to the techniques for multi-scale complex biological systems, from the single bio-molecule to the cell, combining theoretical modeling, experiments, informatics tools and technologies suitable for biological and biomedical research, which are becoming increasingly multidisciplinary, multidimensional and information-driven. The most important concepts on mathematical modeling methodologies and statistical inference, bioinformatics and standards tools to investigate complex biomedical systems are discussed and the prominent literature useful to both the practitioner and the theoretician are presented.

  17. CTBT Integrated Verification System Evaluation Model

    Energy Technology Data Exchange (ETDEWEB)

    Edenburn, M.W.; Bunting, M.L.; Payne, A.C. Jr.

    1997-10-01

    Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia`s Monitoring Systems and Technology Center and has been funded by the US Department of Energy`s Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, top-level, modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM`s unique features is that it integrates results from the various CTBT sensor technologies (seismic, infrasound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection) and location accuracy of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system`s performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. This report describes version 1.2 of IVSEM.

  18. Kinetic Modeling of Biological Systems

    Energy Technology Data Exchange (ETDEWEB)

    Resat, Haluk; Petzold, Linda; Pettigrew, Michel F.

    2009-04-21

    The dynamics of how its constituent components interact define the spatio-temporal response of a natural system to stimuli. Modeling the kinetics of the processes that represent a biophysical system has long been pursued with the aim of improving our understanding of the studied system. Due to the unique properties of biological systems, in addition to the usual difficulties faced in modeling the dynamics of physical or chemical systems, biological simulations encounter difficulties that result from intrinsic multiscale and stochastic nature of the biological processes. This chapter discusses the implications for simulation of models involving interacting species with very low copy numbers, which often occur in biological systems and give rise to significant relative fluctuations. The conditions necessitating the use of stochastic kinetic simulation methods and the mathematical foundations of the stochastic simulation algorithms are presented. How the well-organized structural hierarchies often seen in biological systems can lead to multiscale problems, and possible ways to address the encountered computational difficulties are discussed. We present the details of the existing kinetic simulation methods, and discuss their strengths and shortcomings. A list of the publicly available kinetic simulation tools and our reflections for future prospects are also provided.

  19. Investigation of $^{23}$N in a three-body model

    CERN Document Server

    Zhang, Liuyang; Lyu, Mengjiao; Ji, Chen

    2015-01-01

    The neutron-drip-line nucleus $^{23}$N is investigated in a three-body model consisting of a $^{21}$N core and two valence neutrons. By solving the Faddeev equations with the realistic neutron-neutron potentials and the neutron-core potentials, we calculate the ground state properties of $^{23}$N and also find that there is a new excited state with two-neutron separation energy at about 0.18 MeV. The properties, such as the two-neutron separation energies, are obtained with a good agreement with experiments. By calculating the root-mean-square matter radii, the average distances between the valence neutrons, and the average distances between the core and the center-of-mass of the neutron pair, we show that the excited state of $^{23}$N has a clear halo structure. The correlation density distributions of the three-body system are also calculated to analyze its geometric configuration. At last, we find that the excited state of $^{23}$N has a very small binding energy, a large radius and distribution, and a tri...

  20. Dynamic modeling, property investigation, and adaptive controller design of serial robotic manipulators modeled with structural compliance

    Science.gov (United States)

    Tesar, Delbert; Tosunoglu, Sabri; Lin, Shyng-Her

    1990-01-01

    Research results on general serial robotic manipulators modeled with structural compliances are presented. Two compliant manipulator modeling approaches, distributed and lumped parameter models, are used in this study. System dynamic equations for both compliant models are derived by using the first and second order influence coefficients. Also, the properties of compliant manipulator system dynamics are investigated. One of the properties, which is defined as inaccessibility of vibratory modes, is shown to display a distinct character associated with compliant manipulators. This property indicates the impact of robot geometry on the control of structural oscillations. Example studies are provided to illustrate the physical interpretation of inaccessibility of vibratory modes. Two types of controllers are designed for compliant manipulators modeled by either lumped or distributed parameter techniques. In order to maintain the generality of the results, neither linearization is introduced. Example simulations are given to demonstrate the controller performance. The second type controller is also built for general serial robot arms and is adaptive in nature which can estimate uncertain payload parameters on-line and simultaneously maintain trajectory tracking properties. The relation between manipulator motion tracking capability and convergence of parameter estimation properties is discussed through example case studies. The effect of control input update delays on adaptive controller performance is also studied.

  1. Experimental Investigation and Thermodynamic Modeling of the B2O3-FeO-Fe2O3-Nd2O3 System for Recycling of NdFeB Magnet Scrap

    Science.gov (United States)

    Jakobsson, Lars Klemet; Tranell, Gabriella; Jung, In-Ho

    2016-07-01

    NdFeB magnet scrap is an alternative source of neodymium that could have a significantly lower impact on the environment than current mining and extraction processes. Neodymium can be readily oxidized in the presence of oxygen, which makes it easy to recover neodymium in oxide form. Thermochemical data and phase diagrams for neodymium oxide containing systems is, however, very limited. Thermodynamic modeling of the B2O3-FeO-Fe2O3-Nd2O3 system was hence performed to obtain accurate phase diagrams and thermochemical properties of the system. Key phase diagram experiments were also carried out for the FeO-Nd2O3 system in saturation with iron to improve the accuracy of the present modeling. The modified quasichemical model was used to describe the Gibbs energy of the liquid oxide phase. The Gibbs energy functions of the liquid phase and the solids were optimized to reproduce all available and reliable phase diagram data, and thermochemical properties of the system. Finally the optimized database was applied to calculate conditions for selective oxidation of neodymium from NdFeB magnet waste.

  2. Experimental Investigation and Thermodynamic Modeling of the B2O3-FeO-Fe2O3-Nd2O3 System for Recycling of NdFeB Magnet Scrap

    Science.gov (United States)

    Jakobsson, Lars Klemet; Tranell, Gabriella; Jung, In-Ho

    2017-02-01

    NdFeB magnet scrap is an alternative source of neodymium that could have a significantly lower impact on the environment than current mining and extraction processes. Neodymium can be readily oxidized in the presence of oxygen, which makes it easy to recover neodymium in oxide form. Thermochemical data and phase diagrams for neodymium oxide containing systems is, however, very limited. Thermodynamic modeling of the B2O3-FeO-Fe2O3-Nd2O3 system was hence performed to obtain accurate phase diagrams and thermochemical properties of the system. Key phase diagram experiments were also carried out for the FeO-Nd2O3 system in saturation with iron to improve the accuracy of the present modeling. The modified quasichemical model was used to describe the Gibbs energy of the liquid oxide phase. The Gibbs energy functions of the liquid phase and the solids were optimized to reproduce all available and reliable phase diagram data, and thermochemical properties of the system. Finally the optimized database was applied to calculate conditions for selective oxidation of neodymium from NdFeB magnet waste.

  3. Executive Information Systems' Multidimensional Models

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available Executive Information Systems are design to improve the quality of strategic level of management in organization through a new type of technology and several techniques for extracting, transforming, processing, integrating and presenting data in such a way that the organizational knowledge filters can easily associate with this data and turn it into information for the organization. These technologies are known as Business Intelligence Tools. But in order to build analytic reports for Executive Information Systems (EIS in an organization we need to design a multidimensional model based on the business model from the organization. This paper presents some multidimensional models that can be used in EIS development and propose a new model that is suitable for strategic business requests.

  4. Software and Hardware System for the Investigation of the Thin Film Optical Properties

    Directory of Open Access Journals (Sweden)

    O.V. Fedchenko

    2012-06-01

    Full Text Available Using Torhlabs optical elements and graphic software development system LabVIEW 2010 the software and hardware automation system for the investigation of the optical properties of multilayer film systems was built. The joint genetic algorithm was suggested to process experimental data of Null-ellipsometry and X-ray reflectometry. It was shown that the proposed technique lets one simulate phase transitions, diffusion processes and interface blurring in multilayer film systems very accurate for different computational theoretic models.

  5. Investigation of Management Models in Elite Athlete Injuries

    OpenAIRE

    Chen, Shen-Kai; Cheng, Yun-Min; Huang, Peng-Ju; Chou, Pei-Hsi; Lin, Yen-chung; Hong, Yu-Jue

    2005-01-01

    This cross-sectional study investigated management models among elite athletes participating in sports including baseball, basketball, soccer, volleyball, tennis, softball, football, handball, track and field, swimming, judo, tae-kwon-do, gymnastics, archery, and weight lifting at the Tsoying National Sport Training Center. Data were collected by questionnaire. Of the 393 athletes investigated, 56% were male and 44% were female, with an average age of 20.9 years and average length of athletic...

  6. Investigation on performance of a solar thermophotovoltaic system

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In the light of the thermo-electric conversion principle, a model for predicting the performance of a solar thermophotovoltaic system is presented. The temperature distributions of the emitter for different concentrator ratios are numerically computed and the influence of the concentrator ratio on the system performance is analyzed. Numerical results show that the emitter temperature and the system efficiency increase with increase of the concentrator ratio. The effects of some other factors such as the spectral filter, cell temperature, and the reflectivity of the top and bottom surfaces of the emitter on the conversion performance of the STPV system are discussed.

  7. Numerical Investigation of a Moisture Evaporation Model in Building Materials

    CERN Document Server

    Amirkhanov, I V; Pavlish, M; Puzynina, T P; Puzynin, I V; Sarhadov, I

    2005-01-01

    The properties of a model of moisture evaporation in a porous building material of a rectangular form proposed in [1] are investigated. Algorithms of solving a nonlinear diffusion equation with initial and boundary conditions simulating the dynamic distribution of moisture concentration, calculation of coefficients of a polynomial describing transport of moisture with usage of experimental measurement of moisture concentration in a sample are developed and investigated. Research on the properties of the model is carried out depending on the degree of the polynomial, a set of its coefficients, and the quantity of the used experimental data.

  8. Geological Site Descriptive Model. A strategy for the model development during site investigations

    Energy Technology Data Exchange (ETDEWEB)

    Munier, Raymond; Stenberg, Leif [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Stanfors, Roy [Roy Stanfors Consulting, Lund (Sweden); Milnes, Allan Geoffrey [GEA Consulting, Uppsala (Sweden); Hermanson, Jan [Golder Associates, Stockholm (Sweden); Triumf, Carl-Axel [Geovista, Luleaa (Sweden)

    2003-04-01

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is at present conducting site investigations as a preliminary to building an underground nuclear waste disposal facility in Sweden. This report presents a methodology for constructing, visualising and presenting 3-dimensional geological models, based on data from the site investigations. The methodology integrates with the overall work-flow of the site investigations, from the collection of raw data to the complete site description, as proposed in several earlier technical reports. Further, it is specifically designed for interaction with SICADA - SKB's Site Characterisation Database - and RVS - SKB's Rock Visualisation System. This report is one in a series of strategy documents intended to demonstrate how modelling is to be performed within each discipline. However, it also has a wider purpose, since the geological site descriptive model provides the basic geometrical framework for all the other disciplines. Hence, the wider aim is to present a practical and clear methodology for the analysis and interpretation of input data for use in the construction of the geology-based 3D geometrical model. In addition to the various aspects of modelling described above, the methodology presented here should therefore also provide: guidelines and directives on how systematic interpretation and integration of geo-scientific data from the different investigation methods should be carried out; guidelines on how different geometries should be created in the geological models; guidelines on how the assignment of parameters to the different geological units in RVS should be accomplished; guidelines on the handling of uncertainty at different points in the interpretation process. In addition, it should clarify the relation between the geological model and other models used in the processes of site characterisation, repository layout and safety analysis. In particular, integration and transparency should be

  9. Investigating Student Understanding of Quantum Mechanics Spontaneous Models of Conductivity

    CERN Document Server

    Wittmann, M C; Redish, E F; Wittmann, Michael C.; Steinberg, Richard N.; Redish, Edward F.

    2002-01-01

    Students are taught several models of conductivity, both at the introductory and the advanced level. From early macroscopic models of current flow in circuits, through the discussion of microscopic particle descriptions of electrons flowing in an atomic lattice, to the development of microscopic non-localized band diagram descriptions in advanced physics courses, they need to be able to distinguish between commonly used, though sometimes contradictory, physical models. In investigations of student reasoning about models of conduction, we find that students often are unable to account for the existence of free electrons in a conductor and create models that lead to incorrect predictions and responses contradictory to expert descriptions of the physics. We have used these findings as a guide to creating curriculum materials that we show can be effective helping students to apply the different conduction models more effectively.

  10. Investigating benefits realisation process for enterprise resource planning systems

    OpenAIRE

    Badewi, Amgad

    2016-01-01

    This research aims to investigate the benefit realisation process for ERP systems so as to develop a benefit realization road map whereby organisations can realize the maximum potential of their ERP systems. This research covers two areas: mechanism of implementation and the destination to change (i.e. road map). It has been found that project management and benefits management approaches are necessary for recouping benefits from investing in Information Technologies (IT) pr...

  11. Quark Model and multiquark system

    CERN Document Server

    da Silva, Cristiane Oldoni

    2010-01-01

    The discovery of many particles, especially in the 50's, when the firsts accelerators appeared, caused the searching for a model that would describe in a simple form the whole of known particles. The Quark Model, based in the mathematical structures of group theory, provided in the beginning of the 60's a simplified description of hadronic matter already known, proposing that three particles, called quarks, would originate all the observed hadrons. This model was able to preview the existence of particles that were later detected, confirming its consistency. Extensions of the Quark Model were made in the beginning of the 70's, focusing in describing observed particles that were excited states of the fundamental particles and others that presented new quantum numbers (flavors). Recently, exotic states as tetraquarks and pentaquarks types, also called multiquarks systems, previewed by the model, were observed, what renewed the interest in the way as quarks are confined inside the hadrons. In this article we pre...

  12. Investigation of hydrate formation and transportability in multiphase flow systems

    Science.gov (United States)

    Grasso, Giovanny A.

    The oil and gas industry is moving towards offshore developments in more challenging environments, where evaluating hydrate plugging risks to avoid operational/safety hazards becomes more difficult (Sloan, 2005). Even though mechanistic models for hydrate plug formation have been developed, components for a full comprehensive model are still missing. Prior to this work, research efforts were focused on flowing hydrate particles with relatively little research on hydrate accumulation, leaving hydrate deposition in multiphase flow an unexplored subject. The focus of this thesis was to better understand hydrate deposition as a form of accumu- lation in pipelines. To incorporate the multiphase flow effect, hydrate formation experiments were carried out at varying water cut (WC) from 15 to 100 vol.%, liquid loading (LL) from 50 to 85 vol.%, mixture velocity (vmix) from 0.75 to 3 m/s, for three fluids systems (100 % WC, water in Conroe crude oil emulsions and King Ranch condensate + water) on the ExxonMobil flowloop (4 in. nominal size and 314 ft. long) at Friendswood, TX. For the 100 % WC flowloop tests, hydrate particle distribution transitions beyond a critical hydrate volume concentration, observed values were between 8.2 to 29.4 vol.%, causing a sudden increase in pressure drop (DP). A revised correlation of the transition as a function of Reynolds number and liquid loading was developed. For Conroe emulsions, DP starts increasing at higher hydrate concentrations than King Ranch condensate, many times at 10 vol.%. Experiments with King Ranch show higher relative DP (10 to 25) than Conroe (2 to 10) performed at the same vmix and LL. Cohesive force measurements between cyclopentane hydrate particles were reduced from a value of 3.32 mN/m to 1.26 mN/m when 6 wt.% Conroe was used and to 0.41 mN/m when 5 wt.% Caratinga crude oil was used; similar values were obtained when extracted asphaltenes were used. King Ranch condensate (11 wt.%) did not significantly change the

  13. Infectious disease modeling a hybrid system approach

    CERN Document Server

    Liu, Xinzhi

    2017-01-01

    This volume presents infectious diseases modeled mathematically, taking seasonality and changes in population behavior into account, using a switched and hybrid systems framework. The scope of coverage includes background on mathematical epidemiology, including classical formulations and results; a motivation for seasonal effects and changes in population behavior, an investigation into term-time forced epidemic models with switching parameters, and a detailed account of several different control strategies. The main goal is to study these models theoretically and to establish conditions under which eradication or persistence of the disease is guaranteed. In doing so, the long-term behavior of the models is determined through mathematical techniques from switched systems theory. Numerical simulations are also given to augment and illustrate the theoretical results and to help study the efficacy of the control schemes.

  14. GENERIC model for multiphase systems

    NARCIS (Netherlands)

    Sagis, L.M.C.

    2010-01-01

    GENERIC is a nonequilibrium thermodynamic formalism in which the dynamic behavior of a system is described by a single compact equation involving two types of brackets: a Poisson bracket and a dissipative bracket. This formalism has proved to be a very powerful instrument to model the dynamic behavi

  15. Investigation of 160 Gbit/s optical communication systems

    DEFF Research Database (Denmark)

    Xu, Zhenbo

    2006-01-01

    Gbit/s single channel experiment, two dispersion maps are investigated in transmission spans, namely symmetrical and post dispersion compensation maps taking advantage of the benefit from Raman amplification. The post compensation map offers best power tolerance. WDM systems based on distributed Raman...

  16. Experimental investigation of system effects in stressed-skin elements

    DEFF Research Database (Denmark)

    Dela Stang, B.; Isaksson, T.; Hansson, M.

    What kind of behaviour can be expected from stressed-skin elements at failure? To answer this question was a primary objective of the experimental investigation presented in this report. Systems of 3 roof units, each made of 5 parallel beams, have been tested for load-carrying capacity...

  17. Investigation of the Bruce B delayed neutron detection system

    Energy Technology Data Exchange (ETDEWEB)

    Carriere, O. [Bruce Power, Plant Design Engineering, Chemistry Design, Tiverton, Ontario (Canada); Univ. of Ottawa, Chemical Engineering, Ottawa, Ontario (Canada)

    2003-07-01

    My work at Bruce Power was to investigate the sensitivity of the Bruce B Delayed Neutron Detection System. Specifically the requirement was to determine whether (software) manipulation of data alone would improve sensitivity or whether hardware changes would also be required. This paper will describe the analyses of current and historical data and the results thereof. (author)

  18. Combining experimental observation and modelling in investigating feedback and emotions in repeated selection tasks

    NARCIS (Netherlands)

    Fischer, A.R.H.; Blommaert, F.J.J.; Midden, C.J.H.

    2005-01-01

    People seem to learn tasks even without formal training. This can be modelled as the outcome of a feedback system that accumulates experience. In this paper we investigate such a feedback system, following an iterative research approach. A feedback loop is specified that is detailed using contempora

  19. Combining experimental observation and modelling in investigating feedback and emotions in repeated selection tasks

    NARCIS (Netherlands)

    Fischer, A.R.H.; Blommaert, F.J.J.; Midden, C.J.H.

    2005-01-01

    People seem to learn tasks even without formal training. This can be modelled as the outcome of a feedback system that accumulates experience. In this paper we investigate such a feedback system, following an iterative research approach. A feedback loop is specified that is detailed using

  20. Three-dimensional cell culture models for investigating human viruses.

    Science.gov (United States)

    He, Bing; Chen, Guomin; Zeng, Yi

    2016-10-01

    Three-dimensional (3D) culture models are physiologically relevant, as they provide reproducible results, experimental flexibility and can be adapted for high-throughput experiments. Moreover, these models bridge the gap between traditional two-dimensional (2D) monolayer cultures and animal models. 3D culture systems have significantly advanced basic cell science and tissue engineering, especially in the fields of cell biology and physiology, stem cell research, regenerative medicine, cancer research, drug discovery, and gene and protein expression studies. In addition, 3D models can provide unique insight into bacteriology, virology, parasitology and host-pathogen interactions. This review summarizes and analyzes recent progress in human virological research with 3D cell culture models. We discuss viral growth, replication, proliferation, infection, virus-host interactions and antiviral drugs in 3D culture models.

  1. Software Engineering Support of the Third Round of Scientific Grand Challenge Investigations: An Earth Modeling System Software Framework Strawman Design that Integrates Cactus and UCLA/UCB Distributed Data Broker

    Science.gov (United States)

    Talbot, Bryan; Zhou, Shu-Jia; Higgins, Glenn

    2002-01-01

    One of the most significant challenges in large-scale climate modeling, as well as in high-performance computing in other scientific fields, is that of effectively integrating many software models from multiple contributors. A software framework facilitates the integration task. both in the development and runtime stages of the simulation. Effective software frameworks reduce the programming burden for the investigators, freeing them to focus more on the science and less on the parallel communication implementation, while maintaining high performance across numerous supercomputer and workstation architectures. This document proposes a strawman framework design for the climate community based on the integration of Cactus, from the relativistic physics community, and UCLA/UCB Distributed Data Broker (DDB) from the climate community. This design is the result of an extensive survey of climate models and frameworks in the climate community as well as frameworks from many other scientific communities. The design addresses fundamental development and runtime needs using Cactus, a framework with interfaces for FORTRAN and C-based languages, and high-performance model communication needs using DDB. This document also specifically explores object-oriented design issues in the context of climate modeling as well as climate modeling issues in terms of object-oriented design.

  2. Modeling Cytoskeletal Active Matter Systems

    Science.gov (United States)

    Blackwell, Robert

    Active networks of filamentous proteins and crosslinking motor proteins play a critical role in many important cellular processes. One of the most important microtubule-motor protein assemblies is the mitotic spindle, a self-organized active liquid-crystalline structure that forms during cell division and that ultimately separates chromosomes into two daughter cells. Although the spindle has been intensively studied for decades, the physical principles that govern its self-organization and function remain mysterious. To evolve a better understanding of spindle formation, structure, and dynamics, I investigate course-grained models of active liquid-crystalline networks composed of microtubules, modeled as hard spherocylinders, in diffusive equilibrium with a reservoir of active crosslinks, modeled as hookean springs that can adsorb to microtubules and and translocate at finite velocity along the microtubule axis. This model is investigated using a combination of brownian dynamics and kinetic monte carlo simulation. I have further refined this model to simulate spindle formation and kinetochore capture in the fission yeast S. pombe. I then make predictions for experimentally realizable perturbations in motor protein presence and function in S. pombe.

  3. Animal models to investigate the pathogenesis of rheumatic heart disease

    Directory of Open Access Journals (Sweden)

    Catherine M Rush

    2014-11-01

    Full Text Available Rheumatic fever (RF and rheumatic heart disease (RHD are sequelae of group A streptococcal (GAS infection. Although an autoimmune process has long been considered to be responsible for the initiation of RF/RHD, it is only in the last few decades that the mechanisms involved in the pathogenesis of the inflammatory condition have been unravelled partly due to experimentation on animal models.RF/RHD is a uniquely human condition and modelling this disease in animals is challenging. Antibody and T cell responses to recombinant GAS M protein (rM and the subsequent interactions with cardiac tissue have been predominantly investigated using a rat autoimmune valvulitis model. In Lewis rats immunized with rM, the development of hallmark histological features akin to RF/RHD, both in the myocardial and in valvular tissue have been reported, with the generation of heart tissue cross reactive antibodies and T cells. However, studies of cardiac function are more challenging in such a model. Recently a Lewis rat model of Sydenham’s chorea (SC and related neuropsychiatric disorders has also been described. Rodent models are very useful for assessing disease mechanisms due to the availability of reagents to precisely determine sequential events following infection with GAS or post-challenge with specific proteins and or carbohydrate preparations from GAS. However, studies of cardiac function are more problematic in such models. In this review an historical overview of animal models previously used and those that are currently available will be discussed in terms of their usefulness in modelling different aspects of the disease process. Ultimately, cardiologists, microbiologists, immunologists and physiologists may have to resort to diverse models to investigate different aspects of RF/RHD.

  4. Cotangent Models for Integrable Systems

    Science.gov (United States)

    Kiesenhofer, Anna; Miranda, Eva

    2017-03-01

    We associate cotangent models to a neighbourhood of a Liouville torus in symplectic and Poisson manifolds focusing on b-Poisson/ b-symplectic manifolds. The semilocal equivalence with such models uses the corresponding action-angle theorems in these settings: the theorem of Liouville-Mineur-Arnold for symplectic manifolds and an action-angle theorem for regular Liouville tori in Poisson manifolds (Laurent- Gengoux et al., IntMath Res Notices IMRN 8: 1839-1869, 2011). Our models comprise regular Liouville tori of Poisson manifolds but also consider the Liouville tori on the singular locus of a b-Poisson manifold. For this latter class of Poisson structures we define a twisted cotangent model. The equivalence with this twisted cotangent model is given by an action-angle theorem recently proved by the authors and Scott (Math. Pures Appl. (9) 105(1):66-85, 2016). This viewpoint of cotangent models provides a new machinery to construct examples of integrable systems, which are especially valuable in the b-symplectic case where not many sources of examples are known. At the end of the paper we introduce non-degenerate singularities as lifted cotangent models on b-symplectic manifolds and discuss some generalizations of these models to general Poisson manifolds.

  5. Integrated Distribution Management System for Alabama Principal Investigator

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, Joe

    2013-03-31

    Southern Company Services, under contract with the Department of Energy, along with Alabama Power, Alstom Grid (formerly AREVA T&D) and others moved the work product developed in the first phase of the Integrated Distribution Management System (IDMS) from “Proof of Concept” to true deployment through the activity described in this Final Report. This Project – Integrated Distribution Management Systems in Alabama – advanced earlier developed proof of concept activities into actual implementation and furthermore completed additional requirements to fully realize the benefits of an IDMS. These tasks include development and implementation of a Distribution System based Model that enables data access and enterprise application integration.

  6. Development of an advanced support system for site investigations

    Science.gov (United States)

    Mizuno, T.; Hama, K.; Iwatsuki, T.; Semba, T.

    2009-12-01

    JAEA has the responsibility for R&D to enhance reliability of High Level Waste (HLW) disposal technology and to develop safety assessment methodology with associated databases; these should support both the implementer (NUMO) and the relevant regulatory organizations. With this responsibility, JAEA has initiated development of advanced technology in the field of Knowledge Engineering. Known as the Information Synthesis and Interpretation System (ISIS), it incorporates knowledge currently being obtained in the Underground Research Laboratory (URL) projects in Expert System (ES) modules for the Japanese HLW disposal program. This knowledge includes fundamental understanding of relevant geological environments, technical know-how for the application of complex investigation techniques, experience gained in earlier site work, etc. However, much knowledge is not undocumented because the knowledge is treated as tacit knowledge and, without focused action soon, may be permanently lost. Therefore, a new approach is necessary to transfer the knowledge obtained in these URL projects to support the site characterization and subsequent safety assessment of potential repository sites by NUMO and the formulation of guidelines by regulatory organizations. In this paper, we introduce the ES for selecting tracers for borehole drilling. ES is the system built by applying electronic information technology to support the planning, conducting investigations and assessing of investigation results. Tracers are generally used for borehole drilling to monitor and quantitatively assess the degree of contamination of groundwater by drilling fluid. JAEA uses fluorescent dye as tracer in drilling fluid. When a fluorescent dye is used for drilling, suitable type and concentration must be selected. The technical points to be considered are; 1) linearity of fluorescent spectrum intensity with variations in concentration, 2) pH dependence of fluorescent spectrum intensity, 3) stability of

  7. Investigation of numerical model of Lenze 530 Dc drive in Matlab

    OpenAIRE

    Golodnyi, І.; Lawrinenko, Yu.; Toropov, A.

    2014-01-01

    This paper describes DC drive with thyristor voltage regulator Lenze 530 series. To investigate the transients of the drive system developed numerical model in MatLab is developed. Dual circuit structural diagram of “TCV-DC motor” system with negative feedback for the current and angular speed or current and armature voltage in model is realized. By introduction of current feedback, torque and current limit are achieved and with using of armature voltage or tacho automatic speed stabili...

  8. Liquid–liquid equilibria in the quinary aqueous two-phase system of poly(ethylene glycol) 6000 + sodium sulfate + water in the presence of glucose and ethanol: Experimental investigation and thermodynamic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hekayati, Javad; Roosta, Aliakbar, E-mail: aa.roosta@sutech.ac.ir; Javanmardi, Jafar

    2016-02-10

    Highlights: • Quinary LLE phase equilibria involving PEG 6000 + Na{sub 2}SO{sub 4} + H{sub 2}O + glucose + ethanol. • Favorable partition coefficients of ethanol and glucose. • Satisfactory correlation of the LLE experimental data with the original NRTL model. • Root mean squared deviations (RMSDs) of less than 0.6%. - Abstract: Extractive fermentation processes involving aqueous two-phase systems (ATPSs) are considered as viable means of overcoming the problems associated with product inhibition. Practical development of these processes requires accurate knowledge of the liquid–liquid equilibrium (LLE) of the ATPS forming components alongside the substrate and product of the fermentation process. In this work, the quinary aqueous two-phase LLE of poly(ethylene glycol) 6000 + sodium sulfate + water in the presence of glucose and ethanol have been experimentally determined at 298.15 K using spectrophotometric methods. The resulting LLE data were then satisfactorily correlated by the non-random two-liquid (NRTL) activity coefficient model based on mass fractions. In doing so, the binary energy interaction parameters of the NRTL activity coefficient model were obtained and reported. Calculated RMS deviations below 0.6% demonstrate that the original NRTL activity coefficient model can accurately correlate the LLE data of the quinary aqueous biphasic system of interest.

  9. Probabilistic models for feedback systems.

    Energy Technology Data Exchange (ETDEWEB)

    Grace, Matthew D.; Boggs, Paul T.

    2011-02-01

    In previous work, we developed a Bayesian-based methodology to analyze the reliability of hierarchical systems. The output of the procedure is a statistical distribution of the reliability, thus allowing many questions to be answered. The principal advantage of the approach is that along with an estimate of the reliability, we also can provide statements of confidence in the results. The model is quite general in that it allows general representations of all of the distributions involved, it incorporates prior knowledge into the models, it allows errors in the 'engineered' nodes of a system to be determined by the data, and leads to the ability to determine optimal testing strategies. In this report, we provide the preliminary steps necessary to extend this approach to systems with feedback. Feedback is an essential component of 'complexity' and provides interesting challenges in modeling the time-dependent action of a feedback loop. We provide a mechanism for doing this and analyze a simple case. We then consider some extensions to more interesting examples with local control affecting the entire system. Finally, a discussion of the status of the research is also included.

  10. Modeling Advance Life Support Systems

    Science.gov (United States)

    Pitts, Marvin; Sager, John; Loader, Coleen; Drysdale, Alan

    1996-01-01

    Activities this summer consisted of two projects that involved computer simulation of bioregenerative life support systems for space habitats. Students in the Space Life Science Training Program (SLSTP) used the simulation, space station, to learn about relationships between humans, fish, plants, and microorganisms in a closed environment. One student complete a six week project to modify the simulation by converting the microbes from anaerobic to aerobic, and then balancing the simulation's life support system. A detailed computer simulation of a closed lunar station using bioregenerative life support was attempted, but there was not enough known about system restraints and constants in plant growth, bioreactor design for space habitats and food preparation to develop an integrated model with any confidence. Instead of a completed detailed model with broad assumptions concerning the unknown system parameters, a framework for an integrated model was outlined and work begun on plant and bioreactor simulations. The NASA sponsors and the summer Fell were satisfied with the progress made during the 10 weeks, and we have planned future cooperative work.

  11. Minisuperspace models of discrete systems

    CERN Document Server

    Baytaş, Bekir

    2016-01-01

    A discrete quantum spin system is presented in which several modern methods of canonical quantum gravity can be tested with promising results. In particular, features of interacting dynamics are analyzed with an emphasis on homogeneous configurations and the dynamical building-up and stability of long-range correlations. Different types of homogeneous minisuperspace models are introduced for the system, including one based on condensate states, and shown to capture different aspects of the discrete system. They are evaluated with effective methods and by means of continuum limits, showing good agreement with operator calculations whenever the latter are available. As a possibly quite general result, it is concluded that an analysis of the building-up of long-range correlations in discrete systems requires non-perturbative solutions of the dynamical equations. Some questions related to stability can be analyzed perturbatively, but suggest that matter couplings may be relevant for this question in the context o...

  12. An investigation into why macroscopic systems behave classically

    OpenAIRE

    Hallwood, David W.; Burnett, Keith; Dunningham, Jacob

    2006-01-01

    We study why it is quite so hard to make a superposition of superfluid flows in a Bose-Einstein condensate. To do this we initially investigate the quantum states of $N$ atoms trapped in a 1D ring with a barrier at one position and a phase applied around it. We show how macroscopic superpositions can in principle be produced and investigate factors which affect the superposition. We then use the Bose-Hubbard model to study an array of Bose-Einstein condensates trapped in optical potentials an...

  13. NUMERICAL INVESTIGATION OF FLOW PATTERNS IN DIFFERENT PUMP INTAKE SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    ZHAN Jie-min; WANG Ben-cheng; YU Ling-hui; LI Yok-sheung; TANG Ling

    2012-01-01

    A 3-D numerical model for pump intake is established based on the Navier-Stokes equations with the RNG k-εturbulence model and the VOF method to simulate the free surface.The applicability of the proposed model is validated by a test case of non-symmetric pump-intake bay.The predicted locations,structures and shapes of all vortices are in good agreement with those observed in experiments,though with some differences in vorticity strengths.The flow pattern and the efficiency of five types of pump intake systems are studied.The discharge and the velocity uniformity of the intake system are used as indices to evaluate its performance.

  14. Investigation of Theoretical Models for the Elastic Stiffness of Nanoparticle-Modified Polymer Composites

    Directory of Open Access Journals (Sweden)

    T. Thorvaldsen

    2015-01-01

    Full Text Available Mathematical models are investigated and suggested for the calculation of the elastic stiffness of polymer nanocomposites. Particular emphasis is placed on the effect on the elastic stiffness from agglomerates and the particle interphase properties. The multiphase Mori-Tanaka model and an interphase model are considered as two relevant models. These models only include and require the designation of a few system independent parameters with a clear physical meaning. Extensions of the models are also presented. The model calculations are compared to results from other models, as well as experimental data for different nanocomposites. For nanocomposites with spherical particles and with fiber-like particles, the suggested models are found to be the most flexible ones and are applicable to estimate the stiffness increase of nanocomposites for both low and high particle volume fractions. The suggested theoretical models can hence be considered as a general multiscale “model toolbox” for analysis of various nanocomposites.

  15. Experimental Investigation of Exhaust Thermoelectric System and Application for Vehicle

    Science.gov (United States)

    Liu, X.; Deng, Y. D.; Wang, W. S.; Su, C. Q.

    2015-06-01

    In this case study, an energy harvesting system using a thermoelectric power generator (TEG) has been constructed. Experimental investigation of the hot and cold sides of the thermoelectric modules (TMs) in this system has been undertaken to assess the feasibility for automotive applications. Two test benches have been developed to analyze the TM performance and the TEG system characteristics, especially the temperature difference, open-circuit voltage, and maximum power output of the TM and TEG system. As the performance of a TM is most influenced by the applied pressure and the temperature difference, a thermostatic heater, thermostatic water tank, and clamping devices are used in our experimental apparatus, increasing the output power of the TEG system. Based on the test bench, a new system called the "four-TEGs" system was designed and assembled into a prototype vehicle called "Warrior," and the characteristics of the system such as the maximum power output have been studied in road tests. The results show great potential for application of this technology in future vehicles.

  16. Investigating the Common Origins of Stars Using Dynamical Modeling

    Science.gov (United States)

    Gutierrez, Elizabeth; Ramirez, Ivan

    2017-01-01

    Dynamical modeling of stars’ orbits past in time is a robust method in finding stars of common birth origins. Here we present a dynamical study using the Python package galpy to investigate: 1) solar twins and the possibility of them having common birth origins with our Sun or each other and 2) the planet-hosting star iota Horologii proposed to have formed in the Hyades cluster. Solar twins are stars with spectra nearly identical to the Sun. Using a large sample of solar twins, we applied a standard Galactic model to investigate whether these stars have common origins with the Sun or each other at their respective ages, finding only very weak associations. In our investigation of the planet-hosting star iota Horologii, we challenge previous claims in favor of iota Horologii being an evaporated Hyades star. In our dynamical model, we compare the location of iota Horologii back in time to the average location of a representative sample of true Hyades stars, finding this star to have never converged with the cluster. Our results reveal the fundamental importance of dynamical modeling in the identification of stellar siblings.

  17. Investigation of pressure gradient aware wall modeling in LES

    Science.gov (United States)

    Thiry, Olivier; Winckelmans, Gregoire; Duponcheel, Matthieu

    2015-11-01

    This work focuses on the investigation of various wall modeling strategies for the simulation of high Reynolds number wall-bounded turbulent flows with acceleration and/or deceleration. Our code is based on fourth order finite differences, is momentum conserving, and is energy conserving up to fourth order. We here use a ``channel flow'' set-up, with no slip and wall modeling at the bottom, with slip at the top, and with blowing and/or suction at the top in order to generate the desired acceleration-deceleration profile. Two strategies are investigated and compared. Pressure gradient corrected algebraic models are first considered, and we investigate various local averaging techniques so as to avoid imposing mean profile laws pointwise. RANS sub-layer models are then also considered, where the turbulent viscosity is corrected to account for pressure gradient effects and for resolved LES fluctuations effects. A wall-resolved LES was also performed to provide a reference solution. Research fellow (Ph.D. student) at the F.R.S. - FNRS (Belgium).

  18. Business process analysis of a foodborne outbreak investigation mobile system

    Science.gov (United States)

    Nowicki, T.; Waszkowski, R.; Saniuk, A.

    2016-08-01

    Epidemiological investigation during an outbreak of food-borne disease requires taking a number of activities carried out in the field. This results in a restriction of access to current data about the epidemic and reducing the possibility of transferring information from the field to headquarters. This problem can be solved by using an appropriate system of mobile devices. The purpose of this paper is to present the IT solution based on the central repository for epidemiological investigations and mobile devices designed for use in the field. Based on such a solution business processes can be properly rebuild in a way to achieve better results in the activities of health inspectors.

  19. Modeling-Enabled Systems Nutritional Immunology

    Directory of Open Access Journals (Sweden)

    Meghna eVerma

    2016-02-01

    Full Text Available This review highlights the fundamental role of nutrition in the maintenance of health, the immune response and disease prevention. Emerging global mechanistic insights in the field of nutritional immunology cannot be gained through reductionist methods alone or by analyzing a single nutrient at a time. We propose to investigate nutritional immunology as a massively interacting system of interconnected multistage and multiscale networks that encompass hidden mechanisms by which nutrition, microbiome, metabolism, genetic predisposition and the immune system interact to delineate health and disease. The review sets an unconventional path to applying complex science methodologies to nutritional immunology research, discovery and development through ‘use cases’ centered around the impact of nutrition on the gut microbiome and immune responses. Our systems nutritional immunology analyses, that include modeling and informatics methodologies in combination with pre-clinical and clinical studies, have the potential to discover emerging systems-wide properties at the interface of the immune system, nutrition, microbiome, and metabolism.

  20. NP-Logic Systems and Model-Equivalence Reductions

    CERN Document Server

    Shen, Yuping; 10.4204/EPTCS.24.17

    2010-01-01

    In this paper we investigate the existence of model-equivalence reduction between NP-logic systems which are logic systems with model existence problem in NP. It is shown that among all NP-systems with model checking problem in NP, the existentially quantified propositional logic (\\exists PF) is maximal with respect to poly-time model-equivalent reduction. However, \\exists PF seems not a maximal NP-system in general because there exits a NP-system with model checking problem D^P-complete.

  1. The Control System Modeling Language

    CERN Document Server

    Zagar, K; Sekoranja, M; Tkacik, G; Vodovnik, A; Zagar, Klemen; Plesko, Mark; Sekoranja, Matej; Tkacik, Gasper; Vodovnik, Anze

    2001-01-01

    The well-known Unified Modeling Language (UML) describes software entities, such as interfaces, classes, operations and attributes, as well as relationships among them, e.g. inheritance, containment and dependency. The power of UML lies in Computer Aided Software Engineering (CASE) tools such as Rational Rose, which are also capable of generating software structures from visual object definitions and relations. UML also allows add-ons that define specific structures and patterns in order to steer and automate the design process. We have developed an add-on called Control System Modeling Language (CSML). It introduces entities and relationships that we know from control systems, such as "property" representing a single controllable point/channel, or an "event" specifying that a device is capable of notifying its clients through events. Entities can also possess CSML-specific characteristics, such as physical units and valid ranges for input parameters. CSML is independent of any specific language or technology...

  2. Contextual Modelling of Collaboration System

    Directory of Open Access Journals (Sweden)

    Wafaa DACHRY

    2012-03-01

    Full Text Available Faced with new environmental constraints, firms decide to collaborate in collective entities and adopt new patterns of behavior. So, this firms’ collaboration becomes an unavoidable approach. Indeed, our aim interest in our study is to propose a collaborative information system for supply chain. Our proposed platform ensures cooperation and information sharing between partners in real time. In fact, several questions have to be asked: What is the information nature may be shared between partners? What processes are implemented between actors? What functional services are supported by the platform? In order to answer these questions, we present, in this article, our methodological approach of modelling, called CMCS (Contextual Modelling of Collaborative System

  3. Stochastic Models of Polymer Systems

    Science.gov (United States)

    2016-01-01

    field limit of a dynamical model for polymer systems, Science China Mathematics , (11 2012): 0. doi: TOTAL: 1 Number of Non Peer-Reviewed Conference...4.0 (4.0 max scale): Number of graduating undergraduates funded by a DoD funded Center of Excellence grant for Education , Research and Engineering...undergraduates funded by your agreement who graduated during this period and will receive scholarships or fellowships for further studies in science

  4. Investigation of a Pulsed 1550 nm Fiber Laser System

    Science.gov (United States)

    2015-12-15

    pulses would be to pulse the pump diodes . Currently , the pump diodes in this system are run continuous wave. In the future, the plan is to investigate...information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 2...for illuminator applications. Considerations which impact the wavelength to be used are the transmissivity of the atmosphere and the responsivity of

  5. Investigating the Impact of Global Positioning System Evidence

    OpenAIRE

    Berman, Kiyoshi J; Glisson, William Bradley; Glisson, L. Milton

    2015-01-01

    The continued amalgamation of Global Positioning Systems (GPS) into everyday activities stimulates the idea that these devices will increasingly contribute evidential importance in digital forensics cases. This study investigates the extent to which GPS devices are being used in criminal and civil court cases in the United Kingdom through the inspection of Lexis Nexis, Westlaw, and the British and Irish Legal Information Institute (BAILII) legal databases. The research identified 83 cases whi...

  6. Tidal interactions - crude body model in dynamical investigations

    CERN Document Server

    Gabryszewski, Ryszard

    2011-01-01

    The paper presents results of investigations of small bodies dynamics in a vicinity of giant planets. We used the most simple body model: gravitationally bounded, rotating contact binary affected by the tidal force acting from a planet. Spin variations of such binaries were extensively studied during planetary close encounters. Two main types of dynamical behaviour were observed: (i) huge but interim fluctuations of the angular velocity and (ii) permanent changes of a rotation during a close approach. The first type is observed mainly for fast rotators, while the second one was encountered in a population of slowly spinning objects with periods longer than 12 hours. Conclusions on usability of such crude physical body models in dynamical investigations and a comparison to previous results were attached. The results allow us to formulate a thesis explaining the phenomenon of creation of the extremely slow rotators and an observational excess of such type of objects.

  7. Model reduction of parametrized systems

    CERN Document Server

    Ohlberger, Mario; Patera, Anthony; Rozza, Gianluigi; Urban, Karsten

    2017-01-01

    The special volume offers a global guide to new concepts and approaches concerning the following topics: reduced basis methods, proper orthogonal decomposition, proper generalized decomposition, approximation theory related to model reduction, learning theory and compressed sensing, stochastic and high-dimensional problems, system-theoretic methods, nonlinear model reduction, reduction of coupled problems/multiphysics, optimization and optimal control, state estimation and control, reduced order models and domain decomposition methods, Krylov-subspace and interpolatory methods, and applications to real industrial and complex problems. The book represents the state of the art in the development of reduced order methods. It contains contributions from internationally respected experts, guaranteeing a wide range of expertise and topics. Further, it reflects an important effor t, carried out over the last 12 years, to build a growing research community in this field. Though not a textbook, some of the chapters ca...

  8. Experimental investigation into the degradation of model superconducting windings

    Energy Technology Data Exchange (ETDEWEB)

    Trusov, N.B.; Broitman, I.M.; Pleshchunov, N.N.; Samoilov, S.F.

    1984-01-01

    Results are reported for an investigation into degradation of critical current in model compound-treated windings fabricated from type KETV-2NT superconducting conductors with nonsteady stabilization. It is shown that the way in which the critical current depends on the heat-removal conditions and the rate of entry of current is determined by a mechanism of steady-state heat release occationed by plastic strain of the winding materials under the action of ponderomotive forces.

  9. Investigating ecological speciation in non-model organisms

    DEFF Research Database (Denmark)

    Foote, Andrew David

    2012-01-01

    Background: Studies of ecological speciation tend to focus on a few model biological systems. In contrast, few studies on non-model organisms have been able to infer ecological speciation as the underlying mechanism of evolutionary divergence. Questions: What are the pitfalls in studying ecological...... speciation in non-model organisms that lead to this bias? What alternative approaches might redress the balance? Organism: Genetically differentiated types of the killer whale (Orcinus orca) exhibiting differences in prey preference, habitat use, morphology, and behaviour. Methods: Review of the literature...... variation underlie reproductive isolation between sympatric killer whale types. Perhaps ecological speciation has occurred, but it is hard to prove. We will probably face this outcome whenever we wish to address non-model organisms – species in which it is not easy to apply experimental approaches...

  10. Experimental and analytical investigation of finger-follower cam systems

    Science.gov (United States)

    Hsu, Wensyang

    A predictive dynamic model to compute the motions of components in cam systems, along with the experimental work to verify the model are described. The major components in finger-follower cam systems include the cam, the follower, the hydraulic lash adjuster, and the valve spring, equipped sometimes with a helical valve spring cup damper. In order to fully describe the dynamics of such a system, a lumped/distributed parameter model for the finger-follower cam system with a moving follower pivot is proposed. The valve spring is modeled as a distributed parameter element, and the adjuster is modeled as a stiff spring with viscous damping. The coulomb friction combined with viscous damping between sliding surfaces are also considered. The model predicts toss between the adjuster and the follower at 2535 rpm, and experiment indicates toss starting at 2520 rpm. It is found by simulation that designing hydraulic lash adjuster to be as rigid as possible is essential to successful high speed operation of finger-follower valve trains because a 50 percent decrease in the compliance of the adjuster could increase the maximum camshaft operating speed 150 rpm. Total elimination of the hydraulic lash adjuster is not always feasible because hydraulic lash adjusters can eliminate the clearance between components and do not need to be mechanically, manually adjusted. In order to provide a more stable and precise description on the dynamic response of the adjuster, a two-mode dynamic model for the adjuster is proposed by considering the oil compressibility in the oil chamber, as well as the oil leakage through the annular gap. Furthermore, the effect due to the oil flow from the central orifice to the oil chamber is also studied analytically and experimentally. The inertia effects of the helical valve spring can be suppressed by a cup damper. Damping between the damper and spring wire is found to depend only weakly on relative sliding velocity. The current formula in computing

  11. Investigation of feedback on neutron kinetics and thermal hydraulics from detailed online fuel behavior modeling during a boron dilution transient in a PWR with the two-way coupled code system DYN3D-TRANSURANUS

    Energy Technology Data Exchange (ETDEWEB)

    Holt, L., E-mail: lars.holt@tuev-sued.de [TÜV SÜD Energietechnik GmbH Baden-Württemberg, Gottlieb-Daimler-Str. 7, 70794 Filderstadt (Germany); Technical University München, Department of Nuclear Engineering, Boltzmannstr. 15, D-85748 Garching bei München (Germany); Rohde, U.; Kliem, S.; Baier, S. [Helmholtz-Zentrum Dresden—Rossendorf, Reactor Safety Division, PO Box 510119, D-01314 Dresden (Germany); Seidl, M. [E.ON Kernkraft GmbH, Tresckowstr. 5, D-30457 Hannover (Germany); Van Uffelen, P. [European Commission, Joint Research Centre, Institute for Transuranium Elements, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Macián-Juan, R. [Technical University München, Department of Nuclear Engineering, Boltzmannstr. 15, D-85748 Garching bei München (Germany)

    2016-02-15

    Highlights: • General coupling interface was developed for the fuel performance code TRANSURANUS. • With this new tool simplified fuel behavior models in codes can be replaced. • The reactor dynamics code DYN3D was coupled to TRANSURANUS at assembly level. • The feedback from detailed online fuel behavior modeling is analyzed for reactivity initiated accident (RIA). • The thermal hydraulics can be affected strongly even in fresh fuel assemblies. - Abstract: Recently the reactor dynamics code DYN3D (including an internal fuel behavior model) was coupled to the fuel performance code TRANSURANUS at assembly level. The coupled code system applies the new general TRANSURANUS coupling interface, hence it can be used for one-way or two-way coupling. In the coupling, DYN3D provides process time, time-dependent rod power and thermal hydraulics conditions to TRANSURANUS, which in case of the two-way coupling approach replaces completely the internal DYN3D fuel behavior model and transfers parameters like radial fuel temperature distribution and cladding temperature back to DYN3D. For the first time results of the coupled code system are presented for a post-critical-heat-flux heat transfer. The corresponding heat transfer regime is mostly film boiling, where the cladding temperature can rise several hundreds of degrees. The simulated boron dilution transient assumed an injection of a 36 m{sup 3} slug of under-borated coolant into a German pressurized water reactor (PWR) core initiated from a sub-critical reactor state (extreme reactivity initiated accident (RIA) conditions). The feedback from detailed fuel behavior modeling was found negligible on the neutron kinetics and thermal hydraulics during the first power rise. In a later phase of the transient, the node injected energy can differ 25 J/g, even still around 20 J/g for nodes without film boiling. Furthermore, the thermal hydraulics can be affected strongly even in fresh fuel assemblies, where film boiling

  12. Modelling and Experimental Investigation of an Active Damper

    Directory of Open Access Journals (Sweden)

    Rafael Luís Teixeira

    2006-01-01

    Full Text Available This paper presents a validation methodology of the dynamic behavior of an active viscous damper. The damper has two flexible metallic bellows connected to a rigid reservoir filled with fluid. When one of the bellows is connected to a vibrating structure a periodic flow passes through a variable internal orifice and the damping effect is produced. The size of the orifice is adjusted by a controlled linear piezoelectric actuator that positions the conical core into a conical cavity. The device finite element structural model consists of the valve body and its conical core that are assumed rigid and the flexible bellows are represented by two pistons with elastic suspensions. The flow developed inside the damper is modeled considering the fluid-structure interation, using the Lagrangean-Eulerian formulation. To validate the proposed model a prototype was constructed and experimental tests and numerical simulations are accomplished in the time domain, applying harmonic excitations. The results are compared using curves that relate the damping coefficient with the orifice size and with the input velocity applied at the bellows face. However, for the proper control design and system operation, the direct use of the finite element model becomes unviable due to its high computational time. Then, a reduced second order discrete dynamic model for the damper was developed. The model parameters are identified by analysis in the frequency domain, using impulsive excitation force, for constant and variable orifice sizes. At low excitation frequencies, the damper prototype behaves like a single degree of freedom system which damping factor changes with the orifice size A fuzzy controller was designed and it generates the orifice reference size associated to the desired damping factor. The active system presented better performance when compared to the passive one.

  13. Investigation of GPS/IMU Positioning System for Mining Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Ken L. Stratton

    2006-09-13

    The objective of this project is to investigate the applicability of a combined Global Positioning System and Inertial Measurement Unit (GPS/IMU) for information based displays on earthmoving machines and for automated earthmoving machines in the future. This technology has the potential of allowing an information-based product like Caterpillar's Computer Aided Earthmoving System (CAES) to operate in areas with satellite shading. Satellite shading is an issue in open pit mining because machines are routinely required to operate close to high walls, which reduces significantly the amount of the visible sky to the GPS antenna mounted on the machine. An inertial measurement unit is a product, which provides data for the calculation of position based on sensing accelerations and rotation rates of the machine's rigid body. When this information is coupled with GPS it results in a positioning system that can maintain positioning capability during time periods of shading.

  14. Comparative Geometrical Investigations of Hand-Held Scanning Systems

    Science.gov (United States)

    Kersten, T. P.; Przybilla, H.-J.; Lindstaedt, M.; Tschirschwitz, F.; Misgaiski-Hass, M.

    2016-06-01

    An increasing number of hand-held scanning systems by different manufacturers are becoming available on the market. However, their geometrical performance is little-known to many users. Therefore the Laboratory for Photogrammetry & Laser Scanning of the HafenCity University Hamburg has carried out geometrical accuracy tests with the following systems in co-operation with the Bochum University of Applied Sciences (Laboratory for Photogrammetry) as well as the Humboldt University in Berlin (Institute for Computer Science): DOTProduct DPI-7, Artec Spider, Mantis Vision F5 SR, Kinect v1 + v2, Structure Sensor and Google's Project Tango. In the framework of these comparative investigations geometrically stable reference bodies were used. The appropriate reference data were acquired by measurement with two structured light projection systems (AICON smartSCAN and GOM ATOS I 2M). The comprehensive test results of the different test scenarios are presented and critically discussed in this contribution.

  15. Identification and Modelling of Linear Dynamic Systems

    Directory of Open Access Journals (Sweden)

    Stanislav Kocur

    2006-01-01

    Full Text Available System identification and modelling are very important parts of system control theory. System control is only as good as good is created model of system. So this article deals with identification and modelling problems. There are simple classification and evolution of identification methods, and then the modelling problem is described. Rest of paper is devoted to two most known and used models of linear dynamic systems.

  16. Experimental investigation and constitutive model for lime mudstone.

    Science.gov (United States)

    Wang, Junbao; Liu, Xinrong; Zhao, Baoyun; Song, Zhanping; Lai, Jinxing

    2016-01-01

    In order to investigate the mechanical properties of lime mudstone, conventional triaxial compression tests under different confining pressures (0, 5, 15 and 20 MPa) are performed on lime mudstone samples. The test results show that, from the overall perspective of variation law, the axial peak stress, axial peak strain and elastic modulus of lime mudstone tend to gradually increase with increasing confining pressure. In the range of tested confining pressure, the variations in axial peak stress and elastic modulus with confining pressure can be described with linear functions; while the variation in axial peak strain with confining pressure can be reflected with a power function. To describe the axial stress-strain behavior in failure process of lime mudstone, a new constitutive model is proposed, with the model characteristics analyzed and the parameter determination method put forward. Compared with Wang' model, only one parameter n is added to the new model. The comparison of predicted curves from the model and test data indicates that the new model can preferably simulate the strain softening property of lime mudstone and the axial stress-strain response in rock failure process.

  17. Investigations of dynamical models of B-->ψ/J K*+

    Science.gov (United States)

    Ward, B. F. L.

    1992-03-01

    We investigate representative dynamical models of B-->ψ/J K*+ with an eye toward the suggestion of Kayser, Kuroda, Peccei, and Sanda and Lipkin that such modes may be used to reduce the required luminosity to observe CP violation in B-factory-type devices on the one hand and toward recent impending data from ARGUS which may be used to discriminate among such models, and to corroborate any conclusions from our analysis about such a reduction on the other hand. We find that all three of our relativistically invariant models give CP-even final-state dominance of this decay, in agreement with the initial reports from ARGUS. Further, the method of Lepage and Brodsky is consistent with the ARGUS observation of helicity 0 for the dominant CP-even final states.

  18. Investigation of energy management strategies for photovoltaic systems - A predictive control algorithm

    Science.gov (United States)

    Cull, R. C.; Eltimsahy, A. H.

    1983-01-01

    The present investigation is concerned with the formulation of energy management strategies for stand-alone photovoltaic (PV) systems, taking into account a basic control algorithm for a possible predictive, (and adaptive) controller. The control system controls the flow of energy in the system according to the amount of energy available, and predicts the appropriate control set-points based on the energy (insolation) available by using an appropriate system model. Aspects of adaptation to the conditions of the system are also considered. Attention is given to a statistical analysis technique, the analysis inputs, the analysis procedure, and details regarding the basic control algorithm.

  19. Investigation of energy management strategies for photovoltaic systems - A predictive control algorithm

    Science.gov (United States)

    Cull, R. C.; Eltimsahy, A. H.

    1983-01-01

    The present investigation is concerned with the formulation of energy management strategies for stand-alone photovoltaic (PV) systems, taking into account a basic control algorithm for a possible predictive, (and adaptive) controller. The control system controls the flow of energy in the system according to the amount of energy available, and predicts the appropriate control set-points based on the energy (insolation) available by using an appropriate system model. Aspects of adaptation to the conditions of the system are also considered. Attention is given to a statistical analysis technique, the analysis inputs, the analysis procedure, and details regarding the basic control algorithm.

  20. Incipient Transient Detection in Reactor Systems: Experimental and Theoretical Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Lefteri H. Tsoukalas; S.T. Revankar; X Wang; R. Sattuluri

    2005-09-27

    The main goal of this research was to develop a method for detecting reactor system transients at the earliest possible time through a comprehensive experimental, testing and benchmarking program. This approach holds strong promise for developing new diagnostic technologies that are non-intrusive, generic and highly portable across different systems. It will help in the design of new generation nuclear power reactors, which utilize passive safety systems with a reliable and non-intrusive multiphase flow diagnostic system to monitor the function of the passive safety systems. The main objective of this research was to develop an improved fuzzy logic based detection method based on a comprehensive experimental testing program to detect reactor transients at the earliest possible time, practically at their birth moment. A fuzzy logic and neural network based transient identification methodology and implemented in a computer code called PROTREN was considered in this research and was compared with SPRT (Sequentially Probability Ratio Testing) decision and Bayesian inference. The project involved experiment, theoretical modeling and a thermal-hydraulic code assessment. It involved graduate and undergraduate students participation providing them with exposure and training in advanced reactor concepts and safety systems. In this final report, main tasks performed during the project period are summarized and the selected results are presented. Detailed descriptions for the tasks and the results are presented in previous yearly reports (Revankar et al 2003 and Revankar et al 2004).

  1. A numerical investigation of a thermodielectric power generation system

    Science.gov (United States)

    Sklar, Akiva A.

    The performance of a novel micro-thermodielectric power generation system was investigated in order to determine if thermodielectric power generation can be practically employed and if its performance can compete with current portable power generation technologies. Thermodielectric power generation is a direct energy conversion technology that converts heat directly into high voltage direct current. It requires dielectric (i.e., capacitive) materials whose charge storing capabilities are a function of temperature. This property can be exploited by heating these materials after they are charged; as their temperature increases, their charge storage capability decreases, forcing them to eject a portion of their surface charge. This ejected charge can then be supplied to an appropriate electronic storage device. There are several advantages associated with thermodielectric energy conversion; first, it requires heat addition at relatively low conventional power generation temperatures, i.e., less than 600 °K, and second, devices that utilize it have the potential for excellent power density and device reliability. The predominant disadvantage of using this power generation technique is that the device must operate in an unsteady manner; this can lead to substantial heat transfer losses that limit the device's thermal efficiency. The studied power generation system was designed so that the power generating components of the system (i.e., the thermodielectric materials) are integrated within a micro-scale heat exchange apparatus designed specifically to provide the thermodielectric materials with the unsteady heating and cooling necessary for efficient power generation. This apparatus is designed to utilize a liquid as a working fluid in order to maximize its heat transfer capabilities, minimize the size of the heat exchanger, and maximize the power density of the power generation system. The thermodielectric materials are operated through a power generation cycle that

  2. ISSM: Ice Sheet System Model

    Science.gov (United States)

    Larour, Eric; Schiermeier, John E.; Seroussi, Helene; Morlinghem, Mathieu

    2013-01-01

    In order to have the capability to use satellite data from its own missions to inform future sea-level rise projections, JPL needed a full-fledged ice-sheet/iceshelf flow model, capable of modeling the mass balance of Antarctica and Greenland into the near future. ISSM was developed with such a goal in mind, as a massively parallelized, multi-purpose finite-element framework dedicated to ice-sheet modeling. ISSM features unstructured meshes (Tria in 2D, and Penta in 3D) along with corresponding finite elements for both types of meshes. Each finite element can carry out diagnostic, prognostic, transient, thermal 3D, surface, and bed slope simulations. Anisotropic meshing enables adaptation of meshes to a certain metric, and the 2D Shelfy-Stream, 3D Blatter/Pattyn, and 3D Full-Stokes formulations capture the bulk of the ice-flow physics. These elements can be coupled together, based on the Arlequin method, so that on a large scale model such as Antarctica, each type of finite element is used in the most efficient manner. For each finite element referenced above, ISSM implements an adjoint. This adjoint can be used to carry out model inversions of unknown model parameters, typically ice rheology and basal drag at the ice/bedrock interface, using a metric such as the observed InSAR surface velocity. This data assimilation capability is crucial to allow spinning up of ice flow models using available satellite data. ISSM relies on the PETSc library for its vectors, matrices, and solvers. This allows ISSM to run efficiently on any parallel platform, whether shared or distrib- ISSM: Ice Sheet System Model NASA's Jet Propulsion Laboratory, Pasadena, California uted. It can run on the largest clusters, and is fully scalable. This allows ISSM to tackle models the size of continents. ISSM is embedded into MATLAB and Python, both open scientific platforms. This improves its outreach within the science community. It is entirely written in C/C++, which gives it flexibility in its

  3. Integrated Modeling for Flood Hazard Mapping Using Watershed Modeling System

    National Research Council Canada - National Science Library

    Seyedeh S. Sadrolashrafi; Thamer A. Mohamed; Ahmad R.B. Mahmud; Majid K. Kholghi; Amir Samadi

    2008-01-01

    ...) with the Watershed Modeling System (WMS) for flood modeling is developed. It also interconnects the terrain models and the GIS software, with commercial standard hydrological and hydraulic models, including HEC-1, HEC-RAS, etc...

  4. A data-stream classification system for investigating terrorist threats

    Science.gov (United States)

    Schulz, Alexia; Dettman, Joshua; Gottschalk, Jeffrey; Kotson, Michael; Vuksani, Era; Yu, Tamara

    2016-05-01

    The role of cyber forensics in criminal investigations has greatly increased in recent years due to the wealth of data that is collected and available to investigators. Physical forensics has also experienced a data volume and fidelity revolution due to advances in methods for DNA and trace evidence analysis. Key to extracting insight is the ability to correlate across multi-modal data, which depends critically on identifying a touch-point connecting the separate data streams. Separate data sources may be connected because they refer to the same individual, entity or event. In this paper we present a data source classification system tailored to facilitate the investigation of potential terrorist activity. This taxonomy is structured to illuminate the defining characteristics of a particular terrorist effort and designed to guide reporting to decision makers that is complete, concise, and evidence-based. The classification system has been validated and empirically utilized in the forensic analysis of a simulated terrorist activity. Next-generation analysts can use this schema to label and correlate across existing data streams, assess which critical information may be missing from the data, and identify options for collecting additional data streams to fill information gaps.

  5. Improving models for urban soundscape systems

    Directory of Open Access Journals (Sweden)

    Lawrence Harvey

    2013-12-01

    Full Text Available Large-scale urban soundscape systems offer novel environments for electroacoustic composers, sound artists and sound designers to extend their practice beyond concert halls, art galleries and screen-based digital media. One such system with 156 loudspeakers was installed in 1991 on the Southgate Arts and Leisure Precinct in central Melbourne. Over the next 15 years another three large multichannel soundscape systems were installed on other sites close to the first. A fifth system was established for a single work of art in 2006. Despite this private and public investment in sound art estimated at over one million Australian dollars, several systems are no longer in operation while some remaining systems require technical and curatorial development to ensure their continued cultural presence. To investigate why some systems had failed, interviews were conducted with key players in the development and operation of the five systems. A report from the interviews was produced and is the basis of this paper framing critical issues for improving models of urban soundscape practice. Following a brief overview of related studies in urban sound practices, and descriptions of the system and original study, key themes that emerged from the interviews are examined.

  6. Investigation of novel spent fuel verification system for safeguard application

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Haneol; Yim, Man-Sung [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    Radioactive waste, especially spent fuel, is generated from the operation of nuclear power plants. The final stage of radioactive waste management is disposal which isolates radioactive waste from the accessible environment and allows it to decay. The safety, security, and safeguard of a spent fuel repository have to be evaluated before its operation. Many researchers have evaluated the safety of a repository. These researchers calculated dose to public after the repository is closed depending on their scenario. Because most spent fuel repositories are non-retrievable, research on security or safeguards of spent fuel repositories have to be performed. Design based security or safeguard have to be developed for future repository designs. This study summarizes the requirements of future spent fuel repositories especially safeguards, and suggests a novel system which meets the safeguard requirements. Applying safeguards to a spent fuel repository is becoming increasingly important. The future requirements for a spent fuel repository are suggested by several expert groups, such as ASTOR in IAEA. The requirements emphasizes surveillance and verification. The surveillance and verification of spent fuel is currently accomplished by using the Cerenkov radiation detector while spent fuel is being stored in a fuel pool. This research investigated an advanced spent fuel verification system using a system which converts spent fuel radiation into electricity. The system generates electricity while it is conveyed from a transportation cask to a disposal cask. The electricity conversion system was verified in a lab scale experiment using an 8.51GBq Cs-137 gamma source.

  7. Wind tunnel investigation of a high lift system with pneumatic flow control

    Science.gov (United States)

    Victor, Pricop Mihai; Mircea, Boscoianu; Daniel-Eugeniu, Crunteanu

    2016-06-01

    Next generation passenger aircrafts require more efficient high lift systems under size and mass constraints, to achieve more fuel efficiency. This can be obtained in various ways: to improve/maintain aerodynamic performance while simplifying the mechanical design of the high lift system going to a single slotted flap, to maintain complexity and improve the aerodynamics even more, etc. Laminar wings have less efficient leading edge high lift systems if any, requiring more performance from the trailing edge flap. Pulsed blowing active flow control (AFC) in the gap of single element flap is investigated for a relatively large model. A wind tunnel model, test campaign and results and conclusion are presented.

  8. Numerical investigation for erratic behavior of Kriging surrogate model

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyun Gil; Yi, Seul Gi [KAIST, Daejeon (Korea, Republic of); Choi, Seong Im [Virginia Polytechnic Institute and State University, Blacksburg (United States)

    2014-09-15

    Kriging model is one of popular spatial/temporal interpolation models in engineering field since it could reduce the time resources for the expensive analysis. But generation of the Kriging model is hardly a sinecure because internal semi-variogram structure of the Kriging often reveals numerically unstable or erratic behaviors. In present study, the issues in the maximum likelihood estimation which are the vital-parts of the construction of the Kriging model, is investigated. These issues are divided into two aspects; Issue I is for the erratic response of likelihood function itself, and Issue II is for numerically unstable behaviors in the correlation matrix. For both issues, studies for specific circumstances which might raise the issue, and the reason of that are conducted. Some practical ways further are suggested to cope with them. Furthermore, the issue is studied for practical problem; aerodynamic performance coefficients of two-dimensional airfoil predicted by CFD analysis. Result shows that such erratic behavior of Kriging surrogate model can be effectively resolved by proposed solution. In conclusion, it is expected this paper could be helpful to prevent such an erratic and unstable behavior.

  9. Experimental Investigation on Performance of Pulse Detonation Rocket Engine Model

    Institute of Scientific and Technical Information of China (English)

    LI Qiang; FAN Wei; YAN Chuan-jun; HU Cheng-qi; YE Bin

    2007-01-01

    The PDRE test model used in these experiments utilized kerosene as the fuel, oxygen as oxidizer, and nitrogen as purge gas. The solenoid valves were employed to control intermittent supplies of kerosene, oxygen and purge gas. PDRE test model was 50 mm in inner diameter by 1.2 m long. The DDT (defiagration to detonation transition) enhancement device Shchelkin spiral was used in the test model.The effects of detonation frequency on its time-averaged thrust and specific impulse were experimentally investigated. The obtained results showes that the time-averaged thrust of PDRE test model was approximately proportional to the detonation frequency. For the detonation frequency 20 Hz, the time-averaged thrust was around 107 N, and the specific impulse was around 125 s. The nozzle experiments were conducted using PDRE test model with three traditional nozzles. The experimental results obtained demonstrated that all of those nozzles could augment the thrust and specific impulse. Among those three nozzles, the convergent nozzle had the largest increased augmentation, which was approximately 18%, under the specific condition of the experiment.

  10. Approaching the other: Investigation of a descriptive belief revision model

    Directory of Open Access Journals (Sweden)

    Spyridon Stelios

    2016-12-01

    Full Text Available When an individual—a hearer—is confronted with an opinion expressed by another individual—a speaker—differing from her only in terms of a degree of belief, how will she react? In trying to answer that question this paper reintroduces and investigates a descriptive belief revision model designed to measure approaches. Parameters of the model are the hearer’s credibility account of the speaker, the initial difference between the hearer’s and speaker’s degrees of belief, and the hearer’s resistance to change. Within an interdisciplinary framework, two empirical studies were conducted. A comparison was carried out between empirically recorded revisions and revisions according to the model. Results showed that the theoretical model is highly confirmed. An interesting finding is the measurement of an “unexplainable behaviour” that is not classified either as repulsion or as approach. At a second level of analysis, the model is compared to the Bayesian framework of inference. Structural differences and evidence for optimal descriptive adequacy of the former were highlighted.

  11. Network models in anatomical systems.

    Science.gov (United States)

    Esteve-Altava, Borja; Marugán-Lobón, Jesús; Botella, Héctor; Rasskin-Gutman, Diego

    2011-01-01

    Network theory has been extensively used to model the underlying structure of biological processes. From genetics to ecology, network thinking is changing our understanding of complex systems, specifically how their internal structure determines their overall behavior. Concepts such as hubs, scale-free or small-world networks, common in the complexity literature, are now used more and more in sociology, neurosciences, as well as other anthropological fields. Even though the use of network models is nowadays so widely applied, few attempts have been carried out to enrich our understanding in the classical morphological sciences such as in comparative anatomy or physical anthropology. The purpose of this article is to introduce the usage of network tools in morphology; specifically by building anatomical networks, dealing with the most common analyses and problems, and interpreting their outcome.

  12. Investigation on the Hydrodynamic Performance of An Ultra Deep Turret-Moored FLNG System

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wen-hua; YANG Jian-min; HU Zhi-qiang; XIAO Long-fei; PENG Tao

    2012-01-01

    Hydrodynamic performance of an ultra deep turret-moored Floating Liquefied Natural Gas (FLNG) system is investigated.Hydrodynamic modeling of a turret-moored FLNG system,in consideration of the coupling effects of the vessel and its mooring lines,has been addressed in details.Based on the boundary element method,a 3-D panel model of the FLNG vessel and the related free water surface model are established,and the first-order and second-order mean-drift wave loads and other hydrodynamic coefficients are calculated.A systematic model test program consisting of the white noise wave test,offset test and irregular wave test combined with current and wind,etc.is performed to verify the numerical model.Owing to the depth limit of the water basin,the model test is carried out for the hydrodynamics of the FLNG coupled with only the truncated mooring system.The numerical simulation model features well the hydrodynamic performance of the FLNG system obtained from the model tests.The hydrodynamic characteristics presented in both the numerical simulations and the physical model tests would serve as the guidance for the ongoing project of FLNG system.

  13. Thermodynamic modeling of complex systems

    DEFF Research Database (Denmark)

    Liang, Xiaodong

    Offshore reservoirs represent one of the major growth areas of the oil and gas industry, and environmental safety is one of the biggest challenges for the offshore exploration and production. The oil accidents in the Gulf of Mexico in 1979 and 2010 were two of the biggest disasters in history...... after an oil spill. Engineering thermodynamics could be applied in the state-of-the-art sonar products through advanced artificial technology, if the speed of sound, solubility and density of oil-seawater systems could be satisfactorily modelled. The addition of methanol or glycols into unprocessed well...

  14. Modeling Of Proton Exchange Membrane Fuel Cell Systems

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh

    The objective of this doctoral thesis was to develop reliable steady-state and transient component models suitable to asses-, develop- and optimize proton exchange membrane (PEM) fuel cell systems. Several components in PEM fuel cell systems were characterized and modeled. The developed component...... cell systems. Consequences of indirectly fueling PEM stacks with hydrocarbons using reforming technology were investigated using a PEM stack model including CO poisoning kinetics and a transient Simulink steam reforming system model. Aspects regarding the optimization of PEM fuel cell systems...

  15. Investigation of solar energy utilization in a novel desiccant based air conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Hurdodan, Ertac; Buyukalaca, Orhan [Department of Energy Systems Engineering, Faculty of Engineering, Osmaniye Korkut Ata University (Turkey)], email: ehurdogan@osmaniye.edu.tr, email: obuyukalaca@osmaniye.edu.tr; Yilmaz, Tuncay; Uckan, Irfan [Department of Mechanical Engineering, Faculty of Engineering and Architecture, Cukurova University (Turkey)], email: tunyil@cu.edu.tr, email: iuckan@cu.edu.tr; Hepbasli, Arif [Department of Mechanical Engineering, College of Engineering, King Saud University (Saudi Arabia)], email: ahepbasli.c@ksu.edu.sa

    2011-07-01

    Desiccant-based air-conditioning systems are an alternative to traditional air conditioning units. They have superior humidity control and are usually used in health care facilities to reduce the airborne transmission of disease. In the present study, an innovative, desiccant-based air-conditioning system was designed and tested in Cukurova University, Adana, Turkey. A model for investigating the use of solar energy in the system was developed. Experimental temperatures throughout the cooling season of 2008 and solar radiation data, measured by the State Meteorological Affairs (DMI) over the period 1986-2006, were utilized in the model. A comparison was made between the results obtained from the model and those from the experiments and it was concluded that solar energy could be utilized in the system. Solar energy also increased the coefficient of performance (COP) of the system by between 50% and 120% and was shown to be a cost-effective way of regenerating the desiccant.

  16. Models for Gaze Tracking Systems

    Directory of Open Access Journals (Sweden)

    Villanueva Arantxa

    2007-01-01

    Full Text Available One of the most confusing aspects that one meets when introducing oneself into gaze tracking technology is the wide variety, in terms of hardware equipment, of available systems that provide solutions to the same matter, that is, determining the point the subject is looking at. The calibration process permits generally adjusting nonintrusive trackers based on quite different hardware and image features to the subject. The negative aspect of this simple procedure is that it permits the system to work properly but at the expense of a lack of control over the intrinsic behavior of the tracker. The objective of the presented article is to overcome this obstacle to explore more deeply the elements of a video-oculographic system, that is, eye, camera, lighting, and so forth, from a purely mathematical and geometrical point of view. The main contribution is to find out the minimum number of hardware elements and image features that are needed to determine the point the subject is looking at. A model has been constructed based on pupil contour and multiple lighting, and successfully tested with real subjects. On the other hand, theoretical aspects of video-oculographic systems have been thoroughly reviewed in order to build a theoretical basis for further studies.

  17. Models for Gaze Tracking Systems

    Directory of Open Access Journals (Sweden)

    Arantxa Villanueva

    2007-10-01

    Full Text Available One of the most confusing aspects that one meets when introducing oneself into gaze tracking technology is the wide variety, in terms of hardware equipment, of available systems that provide solutions to the same matter, that is, determining the point the subject is looking at. The calibration process permits generally adjusting nonintrusive trackers based on quite different hardware and image features to the subject. The negative aspect of this simple procedure is that it permits the system to work properly but at the expense of a lack of control over the intrinsic behavior of the tracker. The objective of the presented article is to overcome this obstacle to explore more deeply the elements of a video-oculographic system, that is, eye, camera, lighting, and so forth, from a purely mathematical and geometrical point of view. The main contribution is to find out the minimum number of hardware elements and image features that are needed to determine the point the subject is looking at. A model has been constructed based on pupil contour and multiple lighting, and successfully tested with real subjects. On the other hand, theoretical aspects of video-oculographic systems have been thoroughly reviewed in order to build a theoretical basis for further studies.

  18. An analytical and experimental investigation of natural circulation transients in a model pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Massoud, M

    1987-01-01

    Natural Circulation phenomena in a simulated PWR was investigated experimentally and analytically. The experimental investigation included determination of system characteristics as well as system response to the imposed transient under symmetric and asymmetric operations. System characteristics were used to obtain correlation for heat transfer coefficient in heat exchangers, system flow resistance, and system buoyancy heat. Asymmetric transients were imposed to study flow oscillation and possible instability. The analytical investigation encompassed development of mathematical model for single-phase, steady-state and transient natural circulation as well as modification of existing model for two-phase flow analysis of phenomena such as small break LOCA, high pressure coolant injection and pump coast down. The developed mathematical model for single-phase analysis was computer coded to simulate the imposed transients. The computer program, entitled ''Symmetric and Asymmetric Analysis of Single-Phase Flow (SAS),'' were employed to simulate the imposed transients. It closely emulated the system behavior throughout the transient and subsequent steady-state. Modifications for two-phase flow analysis included addition of models for once-through steam generator and electric heater rods. Both programs are faster than real time. Off-line, they can be used for prediction and training applications while on-line they serve for simulation and signal validation. The programs can also be used to determine the sensitivity of natural circulation behavior to variation of inputs such as secondary distribution and power transients.

  19. Fuel Crime Conceptualization through Specialization of Ontology for Investigation Management System

    Science.gov (United States)

    Cybulka, Jolanta

    We undertook the task of building the conceptual model of a particular economic offense, called "a fuel crime". This model is thought of as a part of a larger conceptualization, which comprises consensual semantics underlying the knowledge base of a system, aimed at supporting the teamwork of investigators of economic crimes. Because such a knowledge-based system represents a perspective on economic crimes, it should be carefully modeled. This can be done with the help of an expressive enough ontology. To achieve our goal we use the constructive descriptions and situations (c.DnS) design pattern, which enables us to construct an extensible, layered ontology in a top-down manner: c.DnS top layer is specialized by the reference ontology for investigation management system, that in turn, is specialized by the ontology of the fuel crime.

  20. Area Logistics System Based on System Dynamics Model

    Institute of Scientific and Technical Information of China (English)

    GUI Shouping; ZHU Qiang; LU Lifang

    2005-01-01

    At present, there are few effective ways to analyze area logistics systems. This paper uses system dynamics to analyze the area logistics system and establishes a system dynamics model for the area logistics system based on the characteristics of the area logistics system and system dynamics. Numerical simulations with the system dynamic model were used to analyze a logistic system. Analysis of the Guangzhou economy shows that the model can reflect the actual state of the system objectively and can be used to make policy and harmonize environment.

  1. Flood Water Crossing: Laboratory Model Investigations for Water Velocity Reductions

    Directory of Open Access Journals (Sweden)

    Kasnon N.

    2014-01-01

    Full Text Available The occurrence of floods may give a negative impact towards road traffic in terms of difficulties in mobilizing traffic as well as causing damage to the vehicles, which later cause them to be stuck in the traffic and trigger traffic problems. The high velocity of water flows occur when there is no existence of objects capable of diffusing the water velocity on the road surface. The shape, orientation and size of the object to be placed beside the road as a diffuser are important for the effective flow attenuation of water. In order to investigate the water flow, a laboratory experiment was set up and models were constructed to study the flow velocity reduction. The velocity of water before and after passing through the diffuser objects was investigated. This paper focuses on laboratory experiments to determine the flow velocity of the water using sensors before and after passing through two best diffuser objects chosen from a previous flow pattern experiment.

  2. Thermal hydraulic investigations and optimization on the EVC system of a PWR by CFD simulation

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Mengmeng [Department of Nuclear Science and Technology, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, 710049 Xi’an (China); Zhang, Dalin, E-mail: dlzhang@mail.xjtu.edu.cn [Department of Nuclear Science and Technology, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, 710049 Xi’an (China); Tang, Mao [China Nuclear Power Design Engineering Co., Ltd., 518124 Shenzhen (China); Wang, Chenglong; Zheng, Meiyin; Qiu, Suizheng [Department of Nuclear Science and Technology, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, 710049 Xi’an (China)

    2015-08-15

    Highlights: • This study constructs a full CFD model for the EVC system of a PWR. • The complex fluid and solid coupling is treated in the computation. • Primary characteristics of the velocity, pressure and temperature distributions in the EVC system are investigated. • The optimization of the EVC system with different inlet boundaries are performed. - Abstract: In order to optimize the design of Reactor Pit Ventilation (EVC) system in a Pressurized Water Reactor (PWR), it is necessary to study the characteristics of the velocity, pressure and temperature fields in the EVC system. A full computational fluid dynamics (CFD) model for the EVC system is constructed by a commercial CFD code, where the complex fluid and solid coupling is treated. The Shear Stress Transport (SST) model is adopted to perform the turbulence calculation. This paper numerically investigates the characteristics of the velocity, pressure and temperature distributions in the EVC system. In particular, the effects of inlet air parameters on the thermal hydraulic characteristics and the reactor pit structure are also discussed for the EVC system optimization. Simulations are carried out with different mesh sizes and boundary conditions for sensitivity analysis. The computational results are important references to optimize the design and verify the rationality of the EVC system.

  3. A system dynamic investigation on Iranian electricity industry

    Directory of Open Access Journals (Sweden)

    Alireza Asadi

    2012-10-01

    Full Text Available Management of energy plays an important role on having sustainable growth on the economy of developing countries. Electricity is part of the main infrastructure of any country, it can help develop many industries, and any shortage in electricity can jeopardize many heavy industries. In Iran, for many years electricity used to be subsided by the government hoping that economy grows faster but this caused a major problem for this industry since the electricity industry could not handle its expenses and faced with somewhat irreversible crises. In this paper, we present a system dynamic investigation to study the existing crises in this sector. The preliminary result of the implementation of system dynamic is that the sector needs to increase its productivity, significantly and lowers the cost of product.

  4. Nonlinear system modeling based on experimental data

    Energy Technology Data Exchange (ETDEWEB)

    PAEZ,THOMAS L.; HUNTER,NORMAN F.

    2000-02-02

    The canonical variate analysis technique is used in this investigation, along with a data transformation algorithm, to identify a system in a transform space. The transformation algorithm involves the preprocessing of measured excitation/response data with a zero-memory-nonlinear transform, specifically, the Rosenblatt transform. This transform approximately maps the measured excitation and response data from its own space into the space of uncorrelated, standard normal random variates. Following this transform, it is appropriate to model the excitation/response relation as linear since Gaussian inputs excite Gaussian responses in linear structures. The linear model is identified in the transform space using the canonical variate analysis approach, and system responses in the original space are predicted using inverse Rosenblatt transformation. An example is presented.

  5. Investigations of the sensitivity of a coronal mass ejection model (ENLIL) to solar input parameters

    DEFF Research Database (Denmark)

    Falkenberg, Thea Vilstrup; Vršnak, B.; Taktakishvili, A.;

    2010-01-01

    investigate the parameter space of the ENLILv2.5b model using the CME event of 25 July 2004. ENLIL is a time‐dependent 3‐D MHD model that can simulate the propagation of cone‐shaped interplanetary coronal mass ejections (ICMEs) through the solar system. Excepting the cone parameters (radius, position...... (CMEs), but in order to predict the caused effects, we need to be able to model their propagation from their origin in the solar corona to the point of interest, e.g., Earth. Many such models exist, but to understand the models in detail we must understand the primary input parameters. Here we......, and initial velocity), all remaining parameters are varied, resulting in more than 20 runs investigated here. The output parameters considered are velocity, density, magnetic field strength, and temperature. We find that the largest effects on the model output are the input parameters of upper limit...

  6. Investigation of Murine Models for Sleep, Wakefulness and Target Discovery

    Science.gov (United States)

    2007-10-01

    subjective day, 7pm-7am w R NR 0 50 100 150 200 250 state c o u n t s F2 Females F2 Males Different from humans, mice exhibit polyphasic sleep with many...early trends, e.g., in the 1p.m. (6 hrs of subjective night) group, became non-significant with additional mice tested • The polyphasic sleep ...REPORT Final report - Investigation of Murine Models for Sleep , Wakefulness and Target Discovery 14. ABSTRACT 16. SECURITY CLASSIFICATION OF

  7. P300 and personality: an investigation with the Cloninger's model.

    Science.gov (United States)

    Hansenne, M

    1999-06-01

    The relationships between P300 and personality have been explored mainly in reference to the model of personality described by Eysenck because of its biological bases. Recently, Cloninger and his colleagues have proposed a model of personality based on four temperaments and three characters. The Temperament and Character Inventory (TCI) is a 226-item self-questionnaire developed to assess these seven dimensions of personality. In the present study, the relationships between these dimensions of personality and P300 have been investigated in 43 normal subjects. The results show that P300 amplitude is positively correlated with the novelty seeking dimension and negatively correlated with the harm avoidance dimension. In contrast, the other dimensions of the TCI were not related to P300 amplitude. Moreover, P300 latency and reaction time were not associated with the TCI dimensions of personality. This study confirms that personality is related to P300.

  8. Enterprise Modelling supported by Manufacturing Systems Theory

    OpenAIRE

    MYKLEBUST, Odd

    2002-01-01

    There exist today a large number of enterprise models or enterprise modelling approaches. In a study of standards and project developed models there are two approaches: CIMOSA “The Open Systems Architecture for CIM” and GERAM, “Generalised Enterprise Reference Architecture”, which show a system orientation that can be further followed as interesting research topics for a system theory oriented approach for enterprise models. In the selection of system theories, manufacturing system theory...

  9. Going Underground: A Field Investigation and Lab Activity on Karst Topography and Water Systems

    Science.gov (United States)

    O'Dell, Gary; Gonzalez-Espada, Wilson

    2011-01-01

    Students learn science best with activities that mirror the way scientists work. This article describes how geologists investigate groundwater flow systems in areas of karst topography--geologic formations shaped by dissolving bedrock--and provides a way for students to replicate this research. Students also use electric current to model water…

  10. Focus Groups for Solar System Investigations with the JWST

    Science.gov (United States)

    Hines, Dean C.; Milam, Stefanie N.; Stansberry, John; Hammel, Heidi B.; Sonneborn, George; Lunine, Jonathan; Rivkin, Andrew; Woodward, Charles; Norwood, Jim; Villanueva, Geronimo; Thomas, Cristina; Santos-Sanz, Pablo; Tiscareno, Matthew; Kestay, Laszlo; Nixon, Conor; Parker, Alex

    2014-11-01

    The unprecedented sensitivity and angular resolution of the James Webb Space Telescope (JWST) will make it NASA’s premier space-based facility for infrared astronomy. This 6.5-meter telescope, which is optimized for observations in the near and mid infrared, will be equipped with four state-of-the-art instruments that include imaging, spectroscopy, and coronagraphy. These instruments, along with the telescope’s moving target capabilities, will enable the infrared study of solar system objects with unprecedented detail. A new white paper (Norwood et al., 2014) provides a general overview of JWST observatory and instrument capabilities for Solar System science, and updates and expands upon an earlier study by Lunine et al. (2010). In order to fully realize the potential of JWST for Solar System observations, we have recently organized 10 focus groups to explore various science use cases in more detail on topics including: Asteroids, Comets, Giant Planets, Mars, Near Earth Objects, Occultations, Rings, Satellites, Titan, and Trans-Neptunian Objects. The findings from these groups will help guide the project as it develops and implements planning tools, observing templates, the data pipeline and archives so that they enable a broad range of Solar System Science investigations. The purpose of this presentation is to raise awareness of the JWST Solar System planning, and to invite participation of DPS members with our Focus Groups and other pre-launch activities.References:Lunine, J., Hammel, H., Schaller, E., Sonneborn, G., Orton, G., Rieke, G., and Rieke, M. 2010, JWST Planetary Observations within the Solar System, http://www.stsci.edu/jwst/doc-archive/white-papers.Norwood, J., Hammel, H., Milam, S.,Stansberry, J., Lunine, J., Chanover, N., Hines, D., Sonneborn, G., Tiscareno, M., Brown, M. and Ferruit, P., 2014, ArXiv e-prints, 1403.6845.

  11. Site investigations: Strategy for rock mechanics site descriptive model

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Johan [JA Streamflow AB, Aelvsjoe (Sweden); Christiansson, Rolf [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Hudson, John [Rock Engineering Consultants, Welwyn Garden City (United Kingdom)

    2002-05-01

    As a part of the planning work for the Site Investigations, SKB has developed a Rock Mechanics Site Descriptive Modelling Strategy. Similar strategies are being developed for other disciplines. The objective of the strategy is that it should guide the practical implementation of evaluating site specific data during the Site Investigations. It is also understood that further development may be needed. This methodology enables the crystalline rock mass to be characterised in terms of the quality at different sites, for considering rock engineering constructability, and for providing the input to numerical models and performance assessment calculations. The model describes the initial stresses and the distribution of deformation and strength properties of the intact rock, of fractures and fracture zones, and of the rock mass. The rock mass mechanical properties are estimated by empirical relations and by numerical simulations. The methodology is based on estimation of mechanical properties using both empirical and heroretical/numerical approaches; and estimation of in situ rock stress using judgement and numerical modelling, including the influence of fracture zones. These approaches are initially used separately, and then combined to produce the required characterisation estimates. The methodology was evaluated with a Test Case at the Aespoe Hard Rock Laboratory in Sweden. The quality control aspects are an important feature of the methodology: these include Protocols to ensure the structure and coherence of the procedures used, regular meetings to enhance communication, feedback from internal and external reviewing, plus the recording of an audit trail of the development steps and decisions made. The strategy will be reviewed and, if required, updated as appropriate.

  12. [Skin slice used as a model for investigating acupuncture effects].

    Science.gov (United States)

    Wang, Li-Na; Schwarz, Wolfgang; Gu, Quan-Bao; Ding, Guang-Hong

    2009-10-01

    To establish an acupoint-connective tissue model for studying the mechanism of acupuncture by using in vitro patch clamp technique in the rat skin slices. The local connective tissue under the corium of "Housanli" (ST 36) area from SD rat was acutely and bluntly separated and fixed in a chamber filled with artificial incubation solution. Mast cells in the prepared connective tissue slice were labeled by toluidine blue (TB) or neutral red (NR). The whole-cell current of mast cells responding to pressure stimulation applied through a patch pipette was recorded in rat slices derived from acupoint ST 36 area by using in vitro patch-clamp technique. 1) After staining with TB and NR, the labeled mast cells were found to distribute in the extracellular matrix of the connective tissue samples, and their degranulation phenomenon could be seen clearly. 2) The whole-cell current of mast cells in response to mechanical stress stimulation was successfully recorded in the connective tissue slices of the rat acupoint ST 36 area. The cellular membrane currents increased evidently when pressure gradients of -30, -60 or -90 cmH2O were applied to the recorded mast cells. The connective tissue slice from the rat ST 36 area may be used as a model for investigating the peripheral mechanism of acupuncture by combining the microtechniques and electrophysiological techniques. The results obtained in this model prove for the first time by electrophysiology that the mast cells in the connective tissue are probably involved in the transduction process of the mechanical signal from acupuncture stimulation. This new model provides a base for investigating the characters of the cells, collagen fibers, proteoglycans, etc. and their interactions in the acupoint connective tissue in the future.

  13. Modeling learning technology systems as business systems

    NARCIS (Netherlands)

    Avgeriou, Paris; Retalis, Symeon; Papaspyrou, Nikolaos

    2003-01-01

    The design of Learning Technology Systems, and the Software Systems that support them, is largely conducted on an intuitive, ad hoc basis, thus resulting in inefficient systems that defectively support the learning process. There is now justifiable, increasing effort in formalizing the engineering o

  14. Modeling learning technology systems as business systems

    NARCIS (Netherlands)

    Avgeriou, Paris; Retalis, Symeon; Papaspyrou, Nikolaos

    2003-01-01

    The design of Learning Technology Systems, and the Software Systems that support them, is largely conducted on an intuitive, ad hoc basis, thus resulting in inefficient systems that defectively support the learning process. There is now justifiable, increasing effort in formalizing the engineering

  15. Global bifurcation investigation of an optimal velocity traffic model with driver reaction time

    Science.gov (United States)

    Orosz, Gábor; Wilson, R. Eddie; Krauskopf, Bernd

    2004-08-01

    We investigate an optimal velocity model which includes the reflex time of drivers. After an analytical study of the stability and local bifurcations of the steady-state solution, we apply numerical continuation techniques to investigate the global behavior of the system. Specifically, we find branches of oscillating solutions connecting Hopf bifurcation points, which may be super- or subcritical, depending on parameters. This analysis reveals several regions of multistability.

  16. Extensive investigation of the generalized dark matter model

    Science.gov (United States)

    Kopp, Michael; Skordis, Constantinos; Thomas, Dan B.

    2016-08-01

    The cold dark matter (CDM) model, wherein the dark matter is treated as a pressureless perfect fluid, provides a good fit to galactic and cosmological data. With the advent of precision cosmology, it should be asked whether this simplest model needs to be extended, and whether doing so could improve our understanding of the properties of dark matter. One established parametrization for generalizing the CDM fluid is the generalized dark matter (GDM) model, in which dark matter is an imperfect fluid with pressure and shear viscosity that fulfill certain postulated closure equations. We investigate these closure equations and the three new parametric functions they contain: the background equation of state w , the speed of sound cs2 and the viscosity cvis2. Taking these functions to be constant parameters, we analyze an exact solution of the perturbed Einstein equations in a flat GDM-dominated universe and discuss the main effects of the three parameters on the cosmic microwave background (CMB). Our analysis suggests that the CMB alone is not able to distinguish between the GDM sound speed and viscosity parameters, but that other observables, such as the matter power spectrum, are required to break this degeneracy. In order to elucidate further the meaning of the GDM closure equations, we also consider other descriptions of imperfect fluids that have a nonperturbative definition and relate these to the GDM model. In particular, we consider scalar fields, an effective field theory (EFT) of fluids, an EFT of large-scale structure, nonequilibrium thermodynamics and tightly coupled fluids. These descriptions could be used to extend the GDM model into the nonlinear regime of structure formation, which is necessary if the wealth of data available on those scales is to be employed in constraining the model. We also derive the initial conditions for adiabatic and isocurvature perturbations in the presence of GDM and standard cosmological fluids and provide the result in a

  17. Modelling Soil Water Characteristic Curves for the Investigation of Hydrophobicity

    Science.gov (United States)

    Hallin, Ingrid; Matthews, Peter; Laudone, Maurizio; Van Keulen, Geertje; Doerr, Stefan; Francis, Lewis; Dudley, Ed; Gazze, Andrea; Quinn, Gerry; Whalley, Richard; Ashton, Rhys

    2016-04-01

    Soil hydrophobicity presents a major challenge for the future, as it reduces both plant-available water and irrigation efficiency, and can increase flooding hazards and erosion. A collaborative research project has been set up in the UK to study hydrophobicity over a wide range of length scales. At core scale, we are investigating the wetting behaviour of water repellent soils in order to model percolation through hydrophobic pore spaces. To that end, water retention measurements were carried out on both wettable and forcibly-wetted water-repellent soils collected from three locations in England and Wales. The data were then fitted with both the commonly used Van Genuchten model and an alternative model from PoreXpert, a software program that analyses and models porous materials. The Van Genuchten model fits a curve to the data using parameters related to air entry suction, irreducible water content and pore size distribution. By contrast, PoreXpert uses a Boltzmann-annealed simplex to find a best-fit curve based on parameters directly related to the void structure of the soil: the size of the voids, the shape of the void size distribution, and how the voids are connected to each other. Both Van Genuchten and PoreXpert fit the experimental data well, but where Van Genuchten forces an S-shaped curve that can mask small variations, PoreXpert gives a closer fit of no pre-defined shape that captures subtle differences between data points. This allows us to calculate differences in the effective pore and throat size distributions, and provides a mechanistic framework from which to model additional hydrologic behaviour in water repellent soil. Simulations of capillary induced wetting based on these mechanistic postulates are then compared to wicking experiments at the core scale, which can then be upscaled and applied to other soils.

  18. Investigating factors determining the use of the clinical care module by nurses through the UTAUT model

    CSIR Research Space (South Africa)

    Zhou, M

    2016-04-01

    Full Text Available Nurses can be empowered in the decision making process if provided with objective diagnostic data. This research applied the Unified Theory of Acceptance and Use of Technology model to investigate the usage of electronic health systems and analyse...

  19. Investigating factors determining the use of the clinical care module by nurses through the UTAUT model

    CSIR Research Space (South Africa)

    Zhou, M

    2016-08-22

    Full Text Available Nurses can be empowered in the decision making process if provided with objective diagnostic data. This research applied the Unified Theory of Acceptance and Use of Technology model to investigate the usage of electronic health systems and analyse...

  20. Nonlinear System Identification and Behavioral Modeling

    CERN Document Server

    Huq, Kazi Mohammed Saidul; Kabir, A F M Sultanul

    2010-01-01

    The problem of determining a mathematical model for an unknown system by observing its input-output data pair is generally referred to as system identification. A behavioral model reproduces the required behavior of the original analyzed system, such as there is a one-to-one correspondence between the behavior of the original system and the simulated system. This paper presents nonlinear system identification and behavioral modeling using a work assignment.

  1. Investigating the cores of fossil systems with Chandra

    CERN Document Server

    Bharadwaj, V; Sanders, J S; Schellenberger, G

    2016-01-01

    We investigate the cores of fossil galaxy groups and clusters (`fossil systems') using archival Chandra data for a sample of 17 fossil systems. We determined the cool-core fraction for fossils via three observable diagnostics, the central cooling time, cuspiness, and concentration parameter. We quantified the dynamical state of the fossils by the X-ray peak/brightest cluster galaxy (BCG), and the X-ray peak/emission weighted centre separations. We studied the X-ray emission coincident with the BCG to detect the presence of potential thermal coronae. A deprojection analysis was performed for z < 0.05 fossils to obtain cooling time and entropy profiles, and to resolve subtle temperature structures. We investigated the Lx-T relation for fossils from the 400d catalogue to see if the scaling relation deviates from that of other groups. Most fossils are identified as cool-core objects via at least two cool-core diagnostics. All fossils have their dominant elliptical galaxy within 50 kpc of the X-ray peak, and mo...

  2. Investigation of Management Models in Elite Athlete Injuries

    Directory of Open Access Journals (Sweden)

    Shen-Kai Chen

    2005-05-01

    Full Text Available This cross-sectional study investigated management models among elite athletes participating in sports including baseball, basketball, soccer, volleyball, tennis, softball, football, handball, track and field, swimming, judo, tae-kwon-do, gymnastics, archery, and weight lifting at the Tsoying National Sport Training Center. Data were collected by questionnaire. Of the 393 athletes investigated, 56% were male and 44% were female, with an average age of 20.9 years and average length of athletic experience of 9.8 years. At the time of the survey, 74.8% had sporting injuries and were being treated with Chinese and/or Western medicine. Among injured athletes, 14.5% chose Western treatment, 8.1% chose Chinese medicine, and 75.4% received combined treatment. There were various reasons for choosing the management model. Most athletes had ordinary self-recognition of sports injury prevention. Their qualified ability for sports injury prevention was 70%. This ability was significantly correlated with age, education, and sports experience. Within Taiwan's current medical and social environment, elite athletes prefer a combination of Eastern and Western treatments for sports injuries. Each of the medical approaches are widely accepted by elite athletes and their coaches. Doctors trained in Western medicine should learn these alternative treatment methods and apply them effectively in athletes, so that a better medical network can be established.

  3. Yarn Strength Modelling Using Fuzzy Expert System

    Directory of Open Access Journals (Sweden)

    Abhijit Majumdar, Ph.D.

    2008-12-01

    Full Text Available Yarn strength modelling and prediction has remained as the cynosure of research for the textile engineers although the investigation in this domain was first reported around one century ago. Several mathematical, statistical and empirical models have been developed in the past only to yield limited success in terms of prediction accuracy and general applicability. In recent years, soft computing tools like artificial neural networks and neural-fuzzy models have been developed, which have shown remarkable prediction accuracy. However, artificial neural network and neural-fuzzy models are trained using enormous amount of noise free input-output data, which are difficult to collect from the spinning industries. In contrast, fuzzy logic based models could be developed by using the experience of the spinner only and it gives good understanding about the roles played by various inputs on the outputs. This paper deals with the modelling of ring spun cotton yarn strength using a simple fuzzy expert system. The prediction accuracy of the model was found to be very encouraging.

  4. Investigating FP Tau’s protoplanetary disk structure through modeling

    Science.gov (United States)

    Brinjikji, Marah; Espaillat, Catherine

    2017-01-01

    This project presents a study aiming to understand the structure of the protoplanetary disk around FP Tau, a very young, very low mass star in the Taurus star-forming region. We have gathered existing optical, Spitzer, Herschel and submillimeter observations to construct the spectral energy distribution (SED) of FP Tau. We have used the D’Alessio et al (2006) physically self-consistent irradiated accretion disk model including dust settling to model the disk of FP Tau. Using this method, the best fit for the SED of FP Tau is a model that includes a gap located 10-20 AU away from the star. This gap is filled with optically thin dust that separates the optically thick dust in the outer disk from the optically thick dust in the inner disk. These characteristics indicate that FP Tau’s protostellar system is best classified as a pre-transitional disk. Near-infrared interferometry in the K-Band from Willson et al 2016 indicates that FP Tau has a small gap located 10-20 AU from the star, which is consistent with the model we produced, lending further support to the pre-transitional disk interpretation. The most likely explanation for the existence of a gap in the disk is a forming planet.

  5. An investigation of modelling and design for software service applications

    Science.gov (United States)

    2017-01-01

    Software services offer the opportunity to use a component-based approach for the design of applications. However, this needs a deeper understanding of how to develop service-based applications in a systematic manner, and of the set of properties that need to be included in the ‘design model’. We have used a realistic application to explore systematically how service-based designs can be created and described. We first identified the key properties of an SOA (service oriented architecture) and then undertook a single-case case study to explore its use in the development of a design for a large-scale application in energy engineering, modelling this with existing notations wherever possible. We evaluated the resulting design model using two walkthroughs with both domain and application experts. We were able to successfully develop a design model around the ten properties identified, and to describe it by adapting existing design notations. A component-based approach to designing such systems does appear to be feasible. However, it needs the assistance of a more integrated set of notations for describing the resulting design model. PMID:28489905

  6. DNA for crime investigation: European co-operation model.

    Science.gov (United States)

    Fiodorova, Anna

    2014-01-01

    The article presents DNA related data exchange mechanism established within the framework of the European Union for the transnational crime investigation. First of all, it provides with the comprehensive overview of legal and practical state of play, pointing out that approved legal basis seeks to ensure legality and reliability in this area by establishing information exchange purposes and competent authorities involved, setting up technical requirements for the DNA analysis and DNA data bases, laying down provisions on accreditation of forensic service providers, foreseeing at least minimum common data protection requirements. Secondly, it reveals that despite being the most exhaustive international regulation on DNA related data exchange among law enforcement and judicial authorities it misses effective data protection mechanism, does not harmonize neither backgrounds for DNA collection in criminal process in general nor storage requirements and that results the variation in categories of subjects related to the crime investigation and included in data bases of different Member States. These gaps make the use of data collected and stored in another Member State vulnerable from the perspective of different rules on evidences' legality within the criminal process. The article also reveals the model's weakness in terms of assessment of its efficiency as statistics gathered for the time being show only number of coincidences (hits) of searched DNA profiles, but not the impact on crime investigation and its results.

  7. An extensive investigation of the Generalised Dark Matter model

    CERN Document Server

    Kopp, Michael; Thomas, Dan B

    2016-01-01

    The Cold Dark Matter (CDM) model, wherein the dark matter is treated as a pressureless perfect fluid, provides a good fit to galactic and cosmological data. With the advent of precision cosmology, it should be asked whether this simplest model needs to be extended, and whether doing so could improve our understanding of the properties of dark matter. One established parameterisation for generalising the CDM fluid is the Generalised Dark Matter (GDM) model, in which dark matter is an imperfect fluid with pressure and shear viscosity that fulfill certain closure equations. We investigate these closure equations and the three new parametric functions they contain: the background equation of state w, the speed of sound c_s^2 and the viscosity c_{vis}^2. Taking these functions to be constant parameters, we analyse an exact solution of the perturbed Einstein equations in a GDM-dominated universe and discuss the main effects of the three parameters on the Cosmic Microwave Background (CMB). Our analysis suggests that...

  8. Mars 2020 Model Based Systems Engineering Pilot

    Science.gov (United States)

    Dukes, Alexandra Marie

    2017-01-01

    The pilot study is led by the Integration Engineering group in NASA's Launch Services Program (LSP). The Integration Engineering (IE) group is responsible for managing the interfaces between the spacecraft and launch vehicle. This pilot investigates the utility of Model-Based Systems Engineering (MBSE) with respect to managing and verifying interface requirements. The main objectives of the pilot are to model several key aspects of the Mars 2020 integrated operations and interface requirements based on the design and verification artifacts from Mars Science Laboratory (MSL) and to demonstrate how MBSE could be used by LSP to gain further insight on the interface between the spacecraft and launch vehicle as well as to enhance how LSP manages the launch service. The method used to accomplish this pilot started through familiarization of SysML, MagicDraw, and the Mars 2020 and MSL systems through books, tutorials, and NASA documentation. MSL was chosen as the focus of the model since its processes and verifications translate easily to the Mars 2020 mission. The study was further focused by modeling specialized systems and processes within MSL in order to demonstrate the utility of MBSE for the rest of the mission. The systems chosen were the In-Flight Disconnect (IFD) system and the Mass Properties process. The IFD was chosen as a system of focus since it is an interface between the spacecraft and launch vehicle which can demonstrate the usefulness of MBSE from a system perspective. The Mass Properties process was chosen as a process of focus since the verifications for mass properties occur throughout the lifecycle and can demonstrate the usefulness of MBSE from a multi-discipline perspective. Several iterations of both perspectives have been modeled and evaluated. While the pilot study will continue for another 2 weeks, pros and cons of using MBSE for LSP IE have been identified. A pro of using MBSE includes an integrated view of the disciplines, requirements, and

  9. Experimental investigation of static ice refrigeration air conditioning system driven by distributed photovoltaic energy system

    Science.gov (United States)

    Xu, Y. F.; Li, M.; Luo, X.; Wang, Y. F.; Yu, Q. F.; Hassanien, R. H. E.

    2016-08-01

    The static ice refrigeration air conditioning system (SIRACS) driven by distributed photovoltaic energy system (DPES) was proposed and the test experiment have been investigated in this paper. Results revealed that system energy utilization efficiency is low because energy losses were high in ice making process of ice slide maker. So the immersed evaporator and co-integrated exchanger were suggested in system structure optimization analysis and the system COP was improved nearly 40%. At the same time, we have researched that ice thickness and ice super-cooled temperature changed along with time and the relationship between system COP and ice thickness was obtained.

  10. Towards investigation of evolution of dynamical systems with independence of time accuracy: more classes of systems

    Energy Technology Data Exchange (ETDEWEB)

    Gurzadyan, V.G. [SIA, Sapienza University of Rome (Italy); Alikhanian National Laboratory and Yerevan State University, Center for Cosmology and Astrophysics, Yerevan (Armenia); Kocharyan, A.A. [Alikhanian National Laboratory and Yerevan State University, Center for Cosmology and Astrophysics, Yerevan (Armenia); Monash University, School of Mathematical Sciences, Clayton (Australia)

    2015-07-15

    The recently developed method (Paper 1) enabling one to investigate the evolution of dynamical systems with an accuracy not dependent on time is developed further. The classes of dynamical systems which can be studied by that method are much extended, now including systems that are: (1) non-Hamiltonian, conservative; (2) Hamiltonian with time-dependent perturbation; (3) non-conservative (with dissipation). These systems cover various types of N-body gravitating systems of astrophysical and cosmological interest, such as the orbital evolution of planets, minor planets, artificial satellites due to tidal, non-tidal perturbations and thermal thrust, evolving close binary stellar systems, and the dynamics of accretion disks. (orig.)

  11. System identification application using Hammerstein model

    Indian Academy of Sciences (India)

    SABAN OZER; HASAN ZORLU; SELCUK METE

    2016-06-01

    Generally, memoryless polynomial nonlinear model for nonlinear part and finite impulse response (FIR) model or infinite impulse response model for linear part are preferred in Hammerstein models in literature. In this paper, system identification applications of Hammerstein model that is cascade of nonlinear second order volterra and linear FIR model are studied. Recursive least square algorithm is used to identify the proposed Hammerstein model parameters. Furthermore, the results are compared to identify the success of proposed Hammerstein model and different types of models

  12. Investigation on rainfall extremes events trough a geoadditive model

    Science.gov (United States)

    Bocci, C.; Caporali, E.; Petrucci, A.; Rossi, G.

    2012-04-01

    Rainfall can be considered a very important variable, and rainfall extreme events analysis of great concern for the enormous impacts that they may have on everyday life particularly when related to intense rainfalls and floods, and hydraulic risk management. On the catchment area of Arno River in Tuscany, Central Italy, a geoadditive mixed model of rainfall extremes is developed. Most of the territory of Arno River has suffered in the past of many severe hydro-geological events, with high levels of risk due to the vulnerability of a unique artistic and cultural heritage. The area has a complex topography that greatly influences the precipitation regime. The dataset is composed by the time series of the annual maxima of daily rainfall recorded in about 400 rain gauges, spatially distributed over the catchment area of about 8.800 km2. The record period covers mainly the second half of 20th century. The rainfall observations are assumed to follow generalized extreme value distributions whose locations are spatially dependent and where the dependence is captured using a geoadditive model. In particular, since rainfall has a natural spatial domain and a significant spatial variability, a spatial hierarchical model for extremes is used. The spatial hierarchical models, in fact, take into account data from all locations, borrowing strength from neighbouring locations when they estimate parameters and are of great interest when small set of data is available, as in the case of rainfall extreme values. Together with rain gauges location variables further physiographic variables are investigated as explanation variables. The implemented geoadditive mixed model of spatially referenced time series of rainfall extreme values, is able to capture the spatial dynamics of the rainfall extreme phenomenon. Since the model shows evidence of a spatial trend in the rainfall extreme dynamic, the temporal dynamic and the time influence can be also taken into account. The implemented

  13. Determination of the limit of detection by X-ray photoelectron spectroscopy for As, Zn and Pb oxides in SiO2 matrix as model systems for environmental investigations

    Science.gov (United States)

    Atzei, Davide; Elsener, Bernhard; Fantauzzi, Marzia; Brundu, Fabio; Rossi, Antonella

    2016-07-01

    In this work the detection limits of arsenic, zinc and lead in silica matrix by X-ray photoelectron spectroscopy (XPS) analysis were evaluated. These elements were selected since they are particularly relevant in environmental investigations. Pure oxides and several binary mixtures with silica at different concentrations of As (III), Zn (II) and Pb (II) oxides obtained by ball milling were analysed by XPS. Inductive-coupled plasma optical emission spectroscopy (ICP-OES) was also exploited for determining their bulk concentration. The linear response of XPS intensity vs weighed (at%) was confirmed. Three different models were here applied to estimate the limit of detection (LOD) of arsenic, zinc and lead and the results were in good agreement. Under the experimental conditions here adopted, the calculated LODs (at%) of arsenic, zinc, and lead as pure oxides and in silica matrix were found to range between 0.1 and 0.3, between 0.04 and 0.1 and between 0.03 and 0.04 respectively.

  14. Modeling of economic systems with Petri nets

    Directory of Open Access Journals (Sweden)

    Pavel Valeryevich Skorodumov

    2014-09-01

    Full Text Available Modeling is one of the most important tools to study complex systems. Components of both continuous and discrete nature are present in the behavior of contemporary economic systems. The article uses formalism of nested hybrid Petri nets as a tool to study complex economic systems. The author describes basic approaches of simulation modelling, concepts of classical Petri nets, modified means of nested hybrid Petri nets, benefits of their use for systems modeling. The article presents the concept of a universal system of simulation modeling. On the basis of considered approaches the article proposes to develop a universal system of simulation modeling on the basis of the modified machine Petri nets

  15. Modeling Power Systems as Complex Adaptive Systems

    Energy Technology Data Exchange (ETDEWEB)

    Chassin, David P.; Malard, Joel M.; Posse, Christian; Gangopadhyaya, Asim; Lu, Ning; Katipamula, Srinivas; Mallow, J V.

    2004-12-30

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We review and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions.

  16. Neuman systems model in holland: an update.

    Science.gov (United States)

    Merks, André; Verberk, Frans; de Kuiper, Marlou; Lowry, Lois W

    2012-10-01

    The authors of this column, leading members of the International Neuman Systems Model Association, provide an update on the use of Neuman systems model in Holland and document the various changes in The Netherlands that have influenced the use of the model in that country. The model's link to systems theory and stress theory are discussed, as well as a shift to greater emphasis on patient self-management. The model is also linked to healthcare quality improvement and interprofessional collaboration in Holland.

  17. Experimental and modelling investigation of surface EMG spike analysis.

    Science.gov (United States)

    Gabriel, David A; Christie, Anita; Inglis, J Greig; Kamen, Gary

    2011-05-01

    A pattern classification method based on five measures extracted from the surface electromyographic (sEMG) signal is used to provide a unique characterization of the interference pattern for different motor unit behaviours. This study investigated the sensitivity of the five sEMG measures during the force gradation process. Tissue and electrode filtering effects were further evaluated using a sEMG model. Subjects (N=8) performed isometric elbow flexion contractions from 0 to 100% MVC. The sEMG signals from the biceps brachii were recorded simultaneously with force. The basic building block of the sEMG model was the detection of single fibre action potentials (SFAPs) through a homogeneous, equivalent isotropic, infinite volume conduction medium. The SFAPs were summed to generate single motor unit action potentials. The physiologic properties from a well-known muscle model and motor unit recruitment and firing rate schemes were combined to generate synthetic sEMG signals. The following pattern classification measures were calculated: mean spike amplitude, mean spike frequency, mean spike slope, mean spike duration, and the mean number of peaks per spike. Root-mean-square amplitude and mean power frequency were also calculated. Taken together, the experimental data and modelling analysis showed that below 50% MVC, the pattern classification measures were more sensitive to changes in force than traditional time and frequency measures. However, there are additional limitations associated with electrode distance from the source that must be explored further. Future experimental work should ensure that the inter-electrode distance is no greater than 1cm to mitigate the effects of tissue filtering.

  18. Performance based investigations of structural systems under fire

    DEFF Research Database (Denmark)

    Gentili, Filippo; Crosti, Chiara; Giuliani, Luisa

    2010-01-01

    Prescriptive measures and procedures developed over the past here are mostly aimed at preventing structural failures of single elements for the time required for the evacuation. The response to fire and fire effects of the structural system as a whole remains often unknown and the survival...... of the construction after this time cannot always be granted. This is even more true in case of unaccounted events like human errors or rare but severe occurrence like a fire after explosion, which cannot be contemplated in the usual design. Even if a structure could be hardly designed to resist fully integer all...... these kinds of events, the mitigation of possible collapse induced by fire should be achieved. In this respect, a performance-based investigation of the structure aimed at highlight fire effects and fire-induced collapse mechanisms becomes of interest. In the paper collapse mechanisms of some simple...

  19. PROGRAM OF INVESTIGATION ON THE TAMMEF SYSTEM APPLICATION METHODS

    Directory of Open Access Journals (Sweden)

    F. Bacci

    2009-12-01

    Full Text Available The TAMMEF System consists of the clinical application of electromagnetic fields piloted at a low frequency by music signals, with simultaneous audition of the same. The working hypothesis expects that the ascertained pain-relieving and therapeutical effects do not depend only on the treatment but also the patient’s disposition. Accordingly, each subject is to be examined by a psychologist, who should also advise whether it may be proper to explain to him/her the music-fields correlation. Conversely, the choice of the pilot music piece, obtained from publications, is to be appraised by a musicologist. Taking into account such conditions and necessities, the criteria for laying out the said program of investigation aimed at verifying the given hypothesis are hereby reported.

  20. An investigation of the dynamic electromechanical coupling effects in machine drive systems driven by asynchronous motors

    Science.gov (United States)

    Szolc, Tomasz; Konowrocki, Robert; Michajłow, Maciej; Pręgowska, Agnieszka

    2014-12-01

    In the paper dynamic electromechanical interaction between the rotating machine drive system and the electric driving motor is considered. The investigations are performed by means of the circuit model of the asynchronous motor as well as using an advanced structural hybrid model of the drive system. Using the analytical solutions applied for the electrical and the mechanical systems the electromagnetic stiffness and coefficient of damping, both generated by the electric motor rotationally interacting with the mechanical system of the given dynamic properties, were determined. By means of experimentally validated computational responses obtained for torsional harmonic excitation induced by the driven machine working tool, a modification of dynamic properties of the mechanical system by the electromagnetic flux between the stator and the rotor has been studied.

  1. New model systems for experimental evolution.

    Science.gov (United States)

    Collins, Sinéad

    2013-07-01

    Microbial experimental evolution uses a few well-characterized model systems to answer fundamental questions about how evolution works. This special section highlights novel model systems for experimental evolution, with a focus on marine model systems that can be used to understand evolutionary responses to global change in the oceans.

  2. Performance modeling of automated manufacturing systems

    Science.gov (United States)

    Viswanadham, N.; Narahari, Y.

    A unified and systematic treatment is presented of modeling methodologies and analysis techniques for performance evaluation of automated manufacturing systems. The book is the first treatment of the mathematical modeling of manufacturing systems. Automated manufacturing systems are surveyed and three principal analytical modeling paradigms are discussed: Markov chains, queues and queueing networks, and Petri nets.

  3. Modeling human operator involvement in robotic systems

    NARCIS (Netherlands)

    Wewerinke, P.H.

    1991-01-01

    A modeling approach is presented to describe complex manned robotic systems. The robotic system is modeled as a (highly) nonlinear, possibly time-varying dynamic system including any time delays in terms of optimal estimation, control and decision theory. The role of the human operator(s) is modeled

  4. Investigation on Experimental Simulation System for Mechanism Motion Reliability Based on the Multibody Simulation Model%基于多体仿真模型的运动机构可靠性仿真试验系统研究

    Institute of Scientific and Technical Information of China (English)

    王慧; 宋笔锋; 喻天翔

    2011-01-01

    Based on the Monte Carlo simulation, a hybrid experimental simulation system for mechanism motion reliability is developed by using the LMS Virtual. Lab and the Visual Basic . NET. In the hybrid simulative experiment system,the LMS Virtual. Lab is used to perform the kinematic and dynamic analysis; the Visual Basic .NET is used to develop the user interface and huild the uncertainty models used for reliability analysis, as well as cxtract the useful result data from the output file of LMS Virtual. Lab. Finally, two examples, i. e. the mechanism motion reliability analysis of a crank-slider mechanism in which geometry errors and joint clearance errors are considered , and the multi-failure mode reliability analysis and sensitivity analvsis of a lock mechanism in which the effect of dynamic characteristics on the reliability are considered, are adopted to illustrate feasibility and efficiency of the hybrid simulation system.%以蒙特卡罗法为理论核心,利用多体运动学和动力学分析软件--LMS Virtual.Lab作为运动机构可靠性分析平台,通过Visual Basic.NET程序设计语言建立用户界面并实现对LMS Virtual.Lab的调用,以进行运动机构的可靠性仿真试验,采用得到的随机变量数据库和结果数据库对运动机构进行典型失效模式的可靠性分析,从而形成了一套可以实现运动机构的可靠性仿真与分析功能的可靠性仿真试验系统.以对心曲柄滑块机构为例,进行了几何尺寸误差和运动副间隙误差影响下的机构运动精度可靠性分析;以某锁机构为例,研究多失效模式下动力学特性对于机构定位可靠性的影响并进行了灵敏性分析.通过这两个实例验证该可靠性仿真试验系统进行机构可靠性仿真试验和可靠性分析的可行性和有效性.

  5. Visual computing model for immune system and medical system.

    Science.gov (United States)

    Gong, Tao; Cao, Xinxue; Xiong, Qin

    2015-01-01

    Natural immune system is an intelligent self-organizing and adaptive system, which has a variety of immune cells with different types of immune mechanisms. The mutual cooperation between the immune cells shows the intelligence of this immune system, and modeling this immune system has an important significance in medical science and engineering. In order to build a comprehensible model of this immune system for better understanding with the visualization method than the traditional mathematic model, a visual computing model of this immune system was proposed and also used to design a medical system with the immune system, in this paper. Some visual simulations of the immune system were made to test the visual effect. The experimental results of the simulations show that the visual modeling approach can provide a more effective way for analyzing this immune system than only the traditional mathematic equations.

  6. A maturity model for SCPMS project-an empirical investigation in large sized Moroccan companies

    Directory of Open Access Journals (Sweden)

    Chafik Okar

    2011-03-01

    Full Text Available In the recent years many studies on maturity model have been carried out. Some refer specifically to maturity models for supply chain and performance measurement system. Starting from an analysis of the existing literature, the aim of this paper is to develop a maturity model for the supply chain performance measurement system (SCPMS project based on the concept of critical success factors (CSFs. This model will be validated by two approaches. The first is a pilot test of the model in a Moroccan supply chain to demonstrate his capacity of assessing the maturity of SCPMS project and whether it can develop an improvement roadmap. The second is an empirical investigation in large sized Moroccan companies by using a survey to depict whether it can evaluate the maturity of SCPMS project in different industries.

  7. An investigation of difficulties experienced by students developing unified modelling language (UML) class and sequence diagrams

    Science.gov (United States)

    Sien, Ven Yu

    2011-12-01

    Object-oriented analysis and design (OOAD) is not an easy subject to learn. There are many challenges confronting students when studying OOAD. Students have particular difficulty abstracting real-world problems within the context of OOAD. They are unable to effectively build object-oriented (OO) models from the problem domain because they essentially do not know "what" to model. This article investigates the difficulties and misconceptions undergraduate students have with analysing systems using unified modelling language analysis class and sequence diagrams. These models were chosen because they represent important static and dynamic aspects of the software system under development. The results of this study will help students produce effective OO models, and facilitate software engineering lecturers design learning materials and approaches for introductory OOAD courses.

  8. Investigation of Synergy Between Electrochemical Capacitors, Flywheels, and Batteries in Hybrid Energy Storage for PV Systems

    Energy Technology Data Exchange (ETDEWEB)

    Miller, John; Sibley, Lewis, B.; Wohlgemuth, John

    1999-06-01

    This report describes the results of a study that investigated the synergy between electrochemical capacitors (ECs) and flywheels, in combination with each other and with batteries, as energy storage subsystems in photovoltaic (PV) systems. EC and flywheel technologies are described and the potential advantages and disadvantages of each in PV energy storage subsystems are discussed. Seven applications for PV energy storage subsystems are described along with the potential market for each of these applications. A spreadsheet model, which used the net present value method, was used to analyze and compare the costs over time of various system configurations based on flywheel models. It appears that a synergistic relationship exists between ECS and flywheels. Further investigation is recommended to quantify the performance and economic tradeoffs of this synergy and its effect on overall system costs.

  9. Cracking in autoclaved aerated concrete: Experimental investigation and XFEM modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ferretti, D., E-mail: daniele.ferretti@unipr.it [Department of Civil, Environmental, Land Management Engineering and Architecture, University of Parma, P.co Area delle Scienze 181/A, 43124 Parma (Italy); Michelini, E. [Department of Civil, Environmental, Land Management Engineering and Architecture, University of Parma, P.co Area delle Scienze 181/A, 43124 Parma (Italy); Rosati, G. [Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza L. Da Vinci 32, 20133 Milano (Italy)

    2015-01-15

    The paper aims to investigate and model cracking development in beams and deep-beams made of autoclaved aerated concrete (AAC). Fracture mechanics of AAC has been first studied by performing three-point bending tests on beams, similar to those commonly used for ordinary concrete elements. In some of these tests, crack growth has been also monitored by using ESPI laser technique. In this way, it has been possible to calibrate the main parameters of a proper cohesive law by means of extended finite element inverse analysis. Subsequently, cracking tests have been also performed on deep-beams, whose behavior is more representative of full scale walls. To validate the proposed cohesive law, deep-beam experimental behavior has been finally simulated through XFEM.

  10. Experimental and numerical investigation of a simplified exhaust model

    Directory of Open Access Journals (Sweden)

    Balázs Vehovszky

    2016-10-01

    Full Text Available A simplified experimental equipment was built to investigate heat radiation and free convection around hot exhaust pipe. Temperatures were measured on the surface of the pipe as like as on heat insulating and -reflecting aluminum shield. Special care was taken to the temperature measuring method: result proved that inappropriate fixing of measuring thermocouples lead to an error of up to 30 % in the temperature-increase values. A detailed 1D numerical model was set up and parametrized so as to the calculation results can be fitted to measured temperature values. In this way thermal properties of the surfaces – as emissivities, absorption coefficients and convective heat transfer coefficients – were determined for temperature sweeps and stationary state cases. The used methods are to be further improved for real automotive parts and higher temperatures.

  11. Externalizing Behaviour for Analysing System Models

    NARCIS (Netherlands)

    Ivanova, Marieta Georgieva; Probst, Christian W.; Hansen, René Rydhof; Kammüller, Florian

    Systems models have recently been introduced to model organisationsandevaluate their vulnerability to threats and especially insiderthreats. Especially for the latter these models are very suitable, since insiders can be assumed to have more knowledge about the attacked organisation than outside

  12. CONTROL SYSTEM IDENTIFICATION THROUGH MODEL MODULATION METHODS

    Science.gov (United States)

    identification has been achieved by using model modulation techniques to drive dynamic models into correspondence with operating control systems. The system ... identification then proceeded from examination of the model and the adaptive loop. The model modulation techniques applied to adaptive control

  13. Investigation of bubble behaviours in wet central heating systems

    Directory of Open Access Journals (Sweden)

    Shefik Ali

    2014-03-01

    Full Text Available A series of experimental measurements has been conducted in order to investigate the bubble behaviours through the horizontal pipe line of the domestic wet central heating systems. Obtained results exposed the effect of 90 degree bend, buoyancy forces on bubbly two phase flow patterns and effect of velocity on void fractions and bubble diameters. Distance chosen for the first sight glass (HSG0 was sufficient enough to note the effect of 90 degree bend on void fraction patterns. Due to the effect of 90 degree bend, position of the peak void fractions across the pipe section lowers, with an increase in bulk fluid velocity. Bubbles tend to flow for longer distance at the bottom of the pipe section. Buoyancy force effect is demonstrated with figures for highest bulk fluid velocity at three different positions. Analysis of four different flow rates at two different saturation ratios show reduction for average bubble diameters and void fractions when bulk fluid velocity increases. An attempt to predict bubble dissolution rates across the horizontal pipeline of the system is made, however results show some uncertainties.

  14. Investigation of bubble behaviours in wet central heating systems

    Science.gov (United States)

    Shefik, Ali; Ge, Yunting

    2014-03-01

    A series of experimental measurements has been conducted in order to investigate the bubble behaviours through the horizontal pipe line of the domestic wet central heating systems. Obtained results exposed the effect of 90 degree bend, buoyancy forces on bubbly two phase flow patterns and effect of velocity on void fractions and bubble diameters. Distance chosen for the first sight glass (HSG0) was sufficient enough to note the effect of 90 degree bend on void fraction patterns. Due to the effect of 90 degree bend, position of the peak void fractions across the pipe section lowers, with an increase in bulk fluid velocity. Bubbles tend to flow for longer distance at the bottom of the pipe section. Buoyancy force effect is demonstrated with figures for highest bulk fluid velocity at three different positions. Analysis of four different flow rates at two different saturation ratios show reduction for average bubble diameters and void fractions when bulk fluid velocity increases. An attempt to predict bubble dissolution rates across the horizontal pipeline of the system is made, however results show some uncertainties.

  15. Investigating follow-up outcome change using hierarchical linear modeling.

    Science.gov (United States)

    Ogrodniczuk, J S; Piper, W E; Joyce, A S

    2001-03-01

    Individual change in outcome during a one-year follow-up period for 98 patients who received either interpretive or supportive psychotherapy was examined using hierarchical linear modeling (HLM). This followed a previous study that had investigated average (treatment condition) change during follow-up using traditional methods of data analysis (repeated measures ANOVA, chi-square tests). We also investigated whether two patient personality characteristics-quality of object relations (QOR) and psychological mindedness (PM)-predicted individual change. HLM procedures yielded findings that were not detected using traditional methods of data analysis. New findings indicated that the rate of individual change in outcome during follow-up varied significantly among the patients. QOR was directly related to favorable individual change for supportive therapy patients, but not for patients who received interpretive therapy. The findings have implications for determining which patients will show long-term benefit following short-term supportive therapy and how to enhance it. The study also found significant associations between QOR and final outcome level.

  16. Two sustainable energy system analysis models

    DEFF Research Database (Denmark)

    Lund, Henrik; Goran Krajacic, Neven Duic; da Graca Carvalho, Maria

    2005-01-01

    This paper presents a comparative study of two energy system analysis models both designed with the purpose of analysing electricity systems with a substantial share of fluctuating renewable energy.......This paper presents a comparative study of two energy system analysis models both designed with the purpose of analysing electricity systems with a substantial share of fluctuating renewable energy....

  17. Experimental Investigation and Theoretical Modeling of Nanosilica Activity in Concrete

    Directory of Open Access Journals (Sweden)

    Han-Seung Lee

    2014-01-01

    Full Text Available This paper presents experimental investigations and theoretical modeling of the hydration reaction of nanosilica blended concrete with different water-to-binder ratios and different nanosilica replacement ratios. The developments of chemically bound water contents, calcium hydroxide contents, and compressive strength of Portland cement control specimens and nanosilica blended specimens were measured at different ages: 1 day, 3 days, 7 days, 14 days, and 28 days. Due to the pozzolanic reaction of nanosilica, the contents of calcium hydroxide in nanosilica blended pastes are considerably lower than those in the control specimens. Compared with the control specimens, the extent of compressive strength enhancement in the nanosilica blended specimens is much higher at early ages. Additionally, a blended cement hydration model that considers both the hydration reaction of cement and the pozzolanic reaction of nanosilica is proposed. The properties of nanosilica blended concrete during hardening were evaluated using the degree of hydration of cement and the reaction degree of nanosilica. The calculated chemically bound water contents, calcium hydroxide contents, and compressive strength were generally consistent with the experimental results.

  18. Alternative DFN model based on initial site investigations at Simpevarp

    Energy Technology Data Exchange (ETDEWEB)

    Darcel, C. [Itasca Consultants, Ecully (France); Davy, S.A.P.; Bour, O.; Dreuzy, J.R. de [Geosciences, Rennes (France)

    2004-12-01

    In this report, we provide a first-order analysis of the fracture network at the Simpevarp site. The first order model is the fracture distribution function, noted, fdf, which provides the number of fractures having a given orientation and length, and belonging to a given volume of observation. The first-order distribution model does not describe higher-order correlation between fracture parameters, such as a possible dependency of fracture length distribution with orientations. We also check that most of the information is contained in this 1st-order distribution model, and that dividing the fracture networks into different sets do not bring a better statistical description. The fracture distribution function contains 3 main distributions: the probability distribution of fracture orientations, the dependency on the size of the sampling domain that may exhibit non-trivial scaling in case of fractal correlations, and the fracture-length density distribution, which appears to be well fitted by a power law. The main scaling parameters are the fractal dimension and the power-law exponent of the fracture length distribution. The former was found to be about equal to the embedding dimension, meaning that fractal correlations are weak and can be neglected in the DFN model. The latter depends on geology, that is either lithology or grain size, with values that ranges from 3.2 for granite-like outcrops to 4 for diorite or monzodiorite outcrops, as well as for the large-scale lineament maps. When analyzing the consistency of the different datasets (boreholes, outcrops, lineament maps), we found that two different DFNs can be described: the first one is derived from the fdf of the outcrop with fine-grained size lithology, and is valid across all scales investigated in this study, from the highly-fractured cores to large-scale maps; the second one is derived from the fdf of the outcrops with coarse-grained size lithology, and is found consistent with cores that present the

  19. Experimental Investigation and Modeling of Copper Smelting Slags

    Science.gov (United States)

    Starodub, Konstantin; Kuminova, Yaroslava; Dinsdale, Alan; Cheverikin, Vladimir; Filichkina, Vera; Saynazarov, Abdukahhar; Khvan, Alexandra; Kondratiev, Alex

    2016-10-01

    Effective extraction of copper from sulfide ores requires careful operation of a copper smelter, which in turn depends very much on chemistry of the feed and resulted slag and matte. For example, chemical composition of copper smelting slags has to be in a certain range to ensure that their properties are within specific limits. Disobeying these rules may lead to complications in smelting operation, poor quality of the copper products, and premature shutdown of the copper smelter. In the present paper the microstructure and phase composition of slags from the Almalyk copper flash smelter were investigated experimentally and then modeled thermodynamically to evaluate potential ways of improvement and optimization of the copper smelting process and its products. The slag samples were taken at different stages of the copper smelting process: on slag tapping, after slag transportation to a deposition site, and at the site. Experimental investigation included the XRD, XRF, and SEM techniques, which were also confirmed by the traditional wet chemistry analysis. Thermodynamic modeling was carried out using thermochemical software package MTDATA, which enables thermodynamic and physical properties of the matte, slag, and gas phases to be calculated in a wide range of temperatures, pressures, and chemical compositions. In addition, slag viscosities and corresponding matte settling rates were estimated using the modified Urbain and Utigard-Warczok models, and the Hadamard-Rybczynski equation, respectively. It was found that the copper content in the slags may vary significantly depending on the location of slag sampling. Cu was found to be present as sulfide particles, almost no Cu was found to be dissolved in the slag. Analysis of microstructure and phase composition showed that major phase found in the samples is fayalite, while other phases are complex spinels (based on magnetite), different sulfides, and a glass-like phase. Thermodynamic calculations demonstrated the

  20. Investigations with spectroscopy, zeta potential and molecular modeling of the non-cooperative behaviour between cyclophosphamide hydrochloride and aspirin upon interaction with human serum albumin: binary and ternary systems from multi-drug therapy.

    Science.gov (United States)

    Omidvar, Zahra; Parivar, Kazem; Sanee, Hamideh; Amiri-Tehranizadeh, Zeinab; Baratian, Ali; Saberi, Mohammad Reza; Asoodeh, Ahmad; Chamani, Jamshidkhan

    2011-08-01

    The interaction between cyclophosphamide hydrochloride (CYC) and aspirin (ASA) with human serum albumin (HSA) was studied by various kind of spectroscopic, ζ potential and molecular modeling under physiological conditions. The fluorescence data showed that the binding of drugs to proteins caused strong static fluorescence quenching. The analysis of the fluorescence quenching of HSA in the binary and ternary systems displayed that ASA was affected by the complex formed between CYC and HSA. Moreover, CYC was influenced by the HSA-ASA complex. The inherent binding information, including the quenching mechanism, binding constants, number of binding sites, effective quenching constant, fraction of the initial fluorescence and thermodynamic parameters were measured by the fluorescence quenching technique at various temperatures. In addition, according to the synchronous fluorescence spectra of HSA, the results showed that the fluorescence quenching of HSA originated from the Trp and Tyr residues, and indicated a conformational change of HSA with the addition of the drugs. Far-UV CD spectra of HSA were recorded before and after the addition of ASA and CYC as binary and ternary systems. An increase in intensity of the positive CD peak of HSA was observed in the presence of the drugs. The results were interpreted by excited interactions between the aromatic residues of the HSA binding sites and the drugs bound to them. The distance r between donor and acceptor was obtained by the Forster energy according to fluorescence resonance energy transfer (FRET) and found to be 2.35 nm and 1.78 nm for CYC and ASA, respectively. This confirmed the existence of static quenching for proteins in the presence of CYC and ASA. Furthermore, docking studies pointed at a reduction of the affinity of each of the drug compounds to the protein in the presence of the other in meaningful amounts. Pre-binding of any of the said compounds forced the second to bind in a non-optimized location and

  1. Graphical Model Debugger Framework for Embedded Systems

    DEFF Research Database (Denmark)

    Zeng, Kebin; Guo, Yu; Angelov, Christo K.

    2010-01-01

    Model Driven Software Development has offered a faster way to design and implement embedded real-time software by moving the design to a model level, and by transforming models to code. However, the testing of embedded systems has remained at the code level. This paper presents a Graphical Model...... Debugger Framework, providing an auxiliary avenue of analysis of system models at runtime by executing generated code and updating models synchronously, which allows embedded developers to focus on the model level. With the model debugger, embedded developers can graphically test their design model...

  2. Particle Tracking Model (PTM) with Coastal Modeling System (CMS)

    Science.gov (United States)

    2014-10-31

    System ( CMS ) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER...www.erdc.usace.army.mil/Missions/WaterResources/CIRP.aspx Coastal Inlets Research Program Particle Tracking Model (PTM) with Coastal Modeling System ( CMS ) The...System ( CMS ), which provides coupled wave and current forcing for PTM simulations. CMS -PTM is implemented in the Surface-water Modeling System, a

  3. A new CFD modeling method for flow blockage accident investigations

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Wenyuan, E-mail: fanwy@mail.ustc.edu.cn; Peng, Changhong, E-mail: pengch@ustc.edu.cn; Chen, Yangli, E-mail: chenyl@mail.ustc.edu.cn; Guo, Yun, E-mail: guoyun79@ustc.edu.cn

    2016-07-15

    Highlights: • Porous-jump treatment is applied to CFD simulation on flow blockages. • Porous-jump treatment predicts consistent results with direct CFD treatment. • Relap5 predicts abnormal flow rate profiles in MTR SFA blockage scenario. • Relap5 fails to simulate annular heat flux in blockage case of annular assembly. • Porous-jump treatment provides reasonable and generalized CFD results. - Abstract: Inlet flow blockages in both flat and annular plate-type fuel assemblies are simulated by (Computational Fluid Dynamics) CFD and system analysis methods, with blockage ratio ranging from 60 to 90%. For all the blockage scenarios, mass flow rate of the blocked channel drops dramatically as blockage ratio increases, while mass flow rates of non-blocked channels are almost steady. As a result of over-simplifications, the system code fails to capture details of mass flow rate profiles of non-blocked channels and power redistribution of fuel plates. In order to acquire generalized CFD results, a new blockage modeling method is developed by using the porous-jump condition. For comparisons, direct CFD simulations are conducted toward postulated blockages. For the porous-jump treatment, conservative flow and heat transfer conditions are predicted for the blocked channel, while consistent predictions are obtained for non-blocked channels. Besides, flow fields in the blocked channel, asymmetric power redistributions of fuel plates, and complex heat transfer phenomena in annular fuel assembly are obtained and discussed. The present study indicates that the porous-jump condition is a reasonable blockage modeling method, which predicts generalized CFD results for flow blockages.

  4. Experimental Investigation and Modelling of a Wet Flue Gas Desulphurisation Pilot Plant

    DEFF Research Database (Denmark)

    Kiil, Søren; Michelsen, Michael Locht; Dam-Johansen, Kim

    1998-01-01

    A detailed model for a wet flue gas desulphurisation (FGD) pilot plant, based on the packed tower concept, has been developed. All important rate determining steps, absorption of SO2, oxidation of HSO3-, dissolution of limestone, and crystallisation of gypsum were included. Population balance...... limestone in the gypsum. Simulations were found to match experimental data for the two limestone types investigated. A parameter study of the model was conducted with the purpose of validating assumptions and extracting information on wet FGD systems. The modelling tools developed may be applicable to other...... wet FGD plants....

  5. In Search for Universal Models. Dimerization of Nitrosobenzenes and Investigation of Some Basic Chemical Concepts

    Directory of Open Access Journals (Sweden)

    Biljan, I.

    2012-09-01

    Full Text Available One of the most exploited approaches in scientific methodology is studying concepts by using a case study. In chemistry, a case study appears in finding a specific molecular and/or reaction system by which the investigated problem can be observed directly "on substance". Thus, the stu- died problem becomes a concrete system, rather than an abstract concept. Most case-study models are designed specifically to deepen one or another chemical problem. However, there exist (although rarely models, which afford their universality, i.e. could serve for modeling of qui- te different, and even epistemologically independent concepts. Systematic investigations of the chemistry of C-nitroso compounds performed in our Laboratory in last few years, have resulted in the discovery that such molecular system may be used as a model for studying a series of basic chemical concepts; selectivity, self-assembly, solid-state reaction mechanisms, photochromism and molecular logics. Since it is known that C-nitroso compounds under specific conditions dime- rize by forming new N=N bond (Scheme 1, the reaction can be used for studying selectivity in the formation of dimers between different nitroso monomers (Fig. 1 and Fig. 2. The system is very convenient for investigation of the structure-selectivity relations.6 It has already been established, especially in the work of Brian Gowenlock, that nitroso compounds in crystal form appear as di- mers. These discoveries inspired us to investigate the kinetics and mechanism of dimerization of nitroso monomers in solid state, because the freshly sublimed nitrosoaromatic compounds appear as crystals of monomers. Consequently, this molecular system is a perfect case-study model for concepts of solid-state reactions, self-organizations in the crystalline forms (Fig. 3, as well as for the8,13 Extending our research of self-organization of nitroso compounds to two-dimensional systems (Fig. 4, we have also de- monstrated the ability of

  6. Investigations in Satellite MIMO Channel Modeling: Accent on Polarization

    Directory of Open Access Journals (Sweden)

    Péter Horváth

    2007-05-01

    Full Text Available Due to the much different environment in satellite and terrestrial links, possibilities in and design of MIMO systems are rather different as well. After pointing out these differences and problems arising from them, two MIMO designs are shown rather well adapted to satellite link characteristics. Cooperative diversity seems to be applicable; its concept is briefly presented without a detailed discussion, leaving solving particular satellite problems to later work. On the other hand, a detailed discussion of polarization time-coded diversity (PTC is given. A physical-statistical model for dual-polarized satellite links is presented together with measuring results validating the model. The concept of 3D polarization is presented as well as briefly describing compact 3D-polarized antennas known from the literature and applicable in satellite links. A synthetic satellite-to-indoor link is constructed and its electromagnetic behavior is simulated via the FDTD (finite-difference time-domain method. Previous result of the authors states that in 3D-PTC situations, MIMO capacity can be about two times higher than SIMO (single-input multiple-output capacity while a diversity gain of nearly 2×3 is further verified via extensive FDTD computer simulation.

  7. Analysis hierarchical model for discrete event systems

    Science.gov (United States)

    Ciortea, E. M.

    2015-11-01

    The This paper presents the hierarchical model based on discrete event network for robotic systems. Based on the hierarchical approach, Petri network is analysed as a network of the highest conceptual level and the lowest level of local control. For modelling and control of complex robotic systems using extended Petri nets. Such a system is structured, controlled and analysed in this paper by using Visual Object Net ++ package that is relatively simple and easy to use, and the results are shown as representations easy to interpret. The hierarchical structure of the robotic system is implemented on computers analysed using specialized programs. Implementation of hierarchical model discrete event systems, as a real-time operating system on a computer network connected via a serial bus is possible, where each computer is dedicated to local and Petri model of a subsystem global robotic system. Since Petri models are simplified to apply general computers, analysis, modelling, complex manufacturing systems control can be achieved using Petri nets. Discrete event systems is a pragmatic tool for modelling industrial systems. For system modelling using Petri nets because we have our system where discrete event. To highlight the auxiliary time Petri model using transport stream divided into hierarchical levels and sections are analysed successively. Proposed robotic system simulation using timed Petri, offers the opportunity to view the robotic time. Application of goods or robotic and transmission times obtained by measuring spot is obtained graphics showing the average time for transport activity, using the parameters sets of finished products. individually.

  8. Investigation of advanced materials based on low-dimensional systems

    Energy Technology Data Exchange (ETDEWEB)

    Babenkov, Sergey

    2016-11-15

    In the framework of this thesis, a new end-station dedicated for dynamic-XPS measurements is created. The end-station is based on a new hemispherical electron spectrometer Argus which is equipped with a high speed detection system. In combination with the high brilliance XUV beamline P04 at PETRA III it provides users a unique tool for fast (down to 0.1 s/spectrum) and detailed investigations compared to existing XPS devices at other synchrotrons. This end-station is integrated into beamline P04 and available for users. During this research work it was widely used for fabrication of samples (Ar{sup +} sputtering, sample heating, film growth etc) and investigation of their properties by means of dynamic-XPS. Using several methods, the atomic and electronic structure of graphene grown on technically relevant substrates of cubic-SiC(001)/Si(001) (''on-axis'' and ''vicinal'') was investigated. We have shown a way to control the number of graphene layers by real-time photoemission measurements during preparation procedure. Using this approach, we have synthesized several samples with different numbers of graphene layers. Consequent atomically resolved STM studies prove the synthesis of a uniform, millimeter-scale graphene overlayer. At the same time, the graphene overlayer possesses rippled morphology and consists of large amount of domain boundaries. Directions of domain boundaries coincide with the directions of carbon atomic chains which were fabricated prior to graphene synthesis on the SiC(001)-c(2 x 2) surface reconstruction. Further, using vicinal-SiC, we synthesized Bernal-stacked trilayer graphene with self-aligned periodic nanodomain boundaries. We proposed a simple method to achieve a current On-Off ratio of 104 by opening a transport gap in Bernal-stacked trilayer graphene. Our low-temperature transport measurements clearly demonstrate that the self-aligned periodic NBs can induce a charge transport gap greater than 1

  9. Clinical investigations for SUS, the Brazilian public health system

    Directory of Open Access Journals (Sweden)

    Ana Patrícia de Paula

    Full Text Available CONTEXT AND OBJECTIVE: Scientific and technological development is crucial for advancing the Brazilian health system and for promoting quality of life. The way in which the Brazilian Ministry of Health has supported clinical research to provide autonomy, self-sufficiency, competitiveness and innovation for the healthcare industrial production complex, in accordance with the National Policy on Science, Technology and Innovation in Healthcare, was analyzed. DESIGN AND SETTING: Descriptive investigation, based on secondary data, conducted at the Department of Science and Technology, Ministry of Health. METHODS: The Ministry of Health's research management database, PesquisaSaúde, was analyzed from 2002 to 2009, using the key word "clinical research" in the fields "primary sub-agenda" or "secondary sub-agenda". The 368 projects retrieved were sorted into six categories: basic biomedical research, preclinical studies, expanded clinical research, clinical trials, infrastructure support and health technology assessment. From a structured review on "clinical research funding", results from selected countries are presented and discussed. RESULTS: The amount invested was R$ 140 million. The largest number of projects supported "basic biomedical research", while the highest amounts invested were in "clinical trials" and "infrastructure support". The southeastern region had the greatest proportion of projects and financial resources. In some respects, Brazil is ahead of other BRICS countries (Russia, India, China and South Africa, especially with regard to establishing a National Clinical Research Network. CONCLUSION: The Ministry of Health ensured investments to encourage clinical research in Brazil and contributed towards promoting cohesion between investigators, health policies and the healthcare industrial production complex.

  10. Extensions in model-based system analysis

    OpenAIRE

    Graham, Matthew R.

    2007-01-01

    Model-based system analysis techniques provide a means for determining desired system performance prior to actual implementation. In addition to specifying desired performance, model-based analysis techniques require mathematical descriptions that characterize relevant behavior of the system. The developments of this dissertation give ex. tended formulations for control- relevant model estimation as well as model-based analysis conditions for performance requirements specified as frequency do...

  11. Osmosis in a minimal model system

    Science.gov (United States)

    Lion, Thomas W.; Allen, Rosalind J.

    2012-12-01

    Osmosis is one of the most important physical phenomena in living and soft matter systems. While the thermodynamics of osmosis is well understood, the underlying microscopic dynamical mechanisms remain the subject of discussion. Unravelling these mechanisms is a prerequisite for understanding osmosis in non-equilibrium systems. Here, we investigate the microscopic basis of osmosis, in a system at equilibrium, using molecular dynamics simulations of a minimal model in which repulsive solute and solvent particles differ only in their interactions with an external potential. For this system, we can derive a simple virial-like relation for the osmotic pressure. Our simulations support an intuitive picture in which the solvent concentration gradient, at osmotic equilibrium, arises from the balance between an outward force, caused by the increased total density in the solution, and an inward diffusive flux caused by the decreased solvent density in the solution. While more complex effects may occur in other osmotic systems, our results suggest that they are not required for a minimal picture of the dynamic mechanisms underlying osmosis.

  12. Inductive modelling of an entrepreneurial system

    OpenAIRE

    Yearworth, M

    2010-01-01

    We describe the development of a novel approach to generating theory about the behaviour of an entrepreneurial or start-up system. The new technology business creation system in and around the cities of Bath and Bristol in the UK was analysed using an inductive modelling approach that hybridises grounded theory with system dynamics, a technique we have called grounded systems modelling. Three models that represent the stages of development of an idea through to successful exploitation have be...

  13. Control model for reconfigurable assembly systems

    Institute of Scientific and Technical Information of China (English)

    Yu Jianfeng; Yin Yuehong; Chen Zhaoneng

    2005-01-01

    This paper proposes knowledge based object-oriented timed colored Petri net, a modeling method for reconfigurable assembly systems. Combining knowledge and object-oriented method into timed colored Petri net, a comprehensive and powerful representation model for control of RAS is obtained. With object-oriented method the whole system can be decomposed into concrete objects explicitly, and their relationships are constructed according to the system assembly requirements. Finally, a simple assembly system modeled by the KTCOPN is presented.

  14. Modelling Immune System: Principles, Models,Analysis and Perspectives

    Institute of Scientific and Technical Information of China (English)

    Xiang-hua Li; Zheng-xuan Wang; Tian-yang Lu; Xiang-jiu Che

    2009-01-01

    The biological immune system is a complex adaptive system. There are lots of benefits for building the model of the immune system. For biological researchers, they can test some hypotheses about the infection process or simulate the responses of some drugs. For computer researchers, they can build distributed, robust and fault tolerant networks inspired by the functions of the immune system. This paper provides a comprehensive survey of the literatures on modelling the immune system. From the methodology perspective, the paper compares and analyzes the existing approaches and models, and also demonstrates the focusing research effort on the future immune models in the next few years.

  15. Comparison of Photovoltaic Models in the System Advisor Model: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Blair, N. J.; Dobos, A. P.; Gilman, P.

    2013-08-01

    The System Advisor Model (SAM) is free software developed by the National Renewable Energy Laboratory (NREL) for predicting the performance of renewable energy systems and analyzing the financial feasibility of residential, commercial, and utility-scale grid-connected projects. SAM offers several options for predicting the performance of photovoltaic (PV) systems. The model requires that the analyst choose from three PV system models, and depending on that choice, possibly choose from three module and two inverter component models. To obtain meaningful results from SAM, the analyst must be aware of the differences between the model options and their applicability to different modeling scenarios. This paper presents an overview the different PV model options and presents a comparison of results for a 200-kW system using different model options.

  16. Graphical Model Debugger Framework for Embedded Systems

    DEFF Research Database (Denmark)

    Zeng, Kebin

    2010-01-01

    Debugger Framework, providing an auxiliary avenue of analysis of system models at runtime by executing generated code and updating models synchronously, which allows embedded developers to focus on the model level. With the model debugger, embedded developers can graphically test their design model......Model Driven Software Development has offered a faster way to design and implement embedded real-time software by moving the design to a model level, and by transforming models to code. However, the testing of embedded systems has remained at the code level. This paper presents a Graphical Model...... and check the running status of the system, which offers a debugging capability on a higher level of abstraction. The framework intends to contribute a tool to the Eclipse society, especially suitable for model-driven development of embedded systems....

  17. Investigation on the Sensitivity Distribution in Electrical Capacitance Tomography System

    Directory of Open Access Journals (Sweden)

    Pan Jiang

    2013-07-01

    Full Text Available The gas-solid-liquid three-phase flow is a very complicated flow pattern in pipeline transportation. By using electrical capacitance tomography (ETC it can acquire the permittivity distribution of the multi-phase. The sensitivity distribution in ETC may affect the analysis of the permittivity distribution of the multi-phase. However, very limited work has been done in this issue. In order to investigate the sensitivity distribution in ETC, this paper employs the finite element method (FEM to establish the principle and components of ECT. The FEM model of the sensitivity distribution as a function of the inter-electrode capacitance was discussed. Simulation tests were carried out to calculate the charge on the electrode pairs to access the potential distribution of the ETC. The analysis results show that the dielectric have great influence on the capacitance value and small distance between the electrode pair and the sensitivity field will produce high sensitivity value. Hence, the findings of this work can provide reference for the design of ECT in practice.

  18. Consumers' influence on the thermal performance of small SDHW systems - theroetical investigation

    DEFF Research Database (Denmark)

    Knudsen, Søren

    2002-01-01

    Usually when SDHW systems are tested and modeled the daily hot-water consumption and consumption pattern are canstant during all days of the test period and simulation period. This is not realistic in 'real life'. Numerical simulations with detailed simulation models have been carried out to inve...... volume for different hot-water consumptions. Furthermore it is investigated how the thermal performance of the systems are influenced by mixing in the solar tank during draw-offs....... to investigate the influence on the thermal performance of different hot-water consumption and consumotion pattern. Two different small SDHW systems are taken into the calculation, a low-flow system where the heat storage consists of a mantle tank and a high flow system with an internal heat exchanger spiral......-water consumption and consumption pattern vary from day to day and furthermore weekends and holidays are taken into account in this profile. Different volumes of the tanks in the two systems are taken into the calculation in order to determine how the thermal performance of the systems is influenced by the tank...

  19. Time-Dependent Traveling Wave Tube Model for Intersymbol Interference Investigations

    Science.gov (United States)

    Kory, Carol L.; Andro, Monty; Downey, Alan (Technical Monitor)

    2001-01-01

    For the first time, a computational model has been used to provide a direct description of the effects of the traveling wave tube (TWT) on modulated digital signals. The TWT model comprehensively takes into account the effects of frequency dependent AM/AM and AM/PM conversion, gain and phase ripple; drive-induced oscillations; harmonic generation; intermodulation products; and backward waves. Thus, signal integrity can be investigated in the presence of these sources of potential distortion as a function of the physical geometry of the high power amplifier and the operational digital signal. This method promises superior predictive fidelity compared to methods using TWT models based on swept-amplitude and/or swept-frequency data. The fully three-dimensional (3D), time-dependent, TWT interaction model using the electromagnetic code MAFIA is presented. This model is used to investigate assumptions made in TWT black-box models used in communication system level simulations. In addition, digital signal performance, including intersymbol interference (ISI), is compared using direct data input into the MAFIA model and using the system level analysis tool, SPW.

  20. Executable Design Models for a Pervasive Healthcare Middleware System

    DEFF Research Database (Denmark)

    Jørgensen, Jens Bæk; Christensen, Søren

    2002-01-01

     UML is applied in the design of a pervasive healthcare middleware system for the hospitals in Aarhus County, Denmark. It works well for the modelling of static aspects of the system, but with respect to describing the behaviour, UML is not sufficient. This paper explains why and, as a remedy......, suggests to supplement the UML models with behaviour descriptions in the modelling language Coloured Petri Nets, CPN. CPN models are executable and fine-grained, and a combined use of UML and CPN thus supports design-time investigation of the detailed behaviour of system components. In this way...

  1. Dynamic modelling as an element of the availibility and process oriented behaviour investigation of complex power plants; Dynamische Modellbildung als Element von verfuegbarkeits- und prozessorientierten Untersuchungen komplexer kraftwerkstechnischer Systeme

    Energy Technology Data Exchange (ETDEWEB)

    Klatt, M.

    2007-12-20

    A software-tool was developed, which, with its specially built component library, allows the modelling of availability and dynamic behaviour of large scale power plant units. The requested graphic representation near to the process flow schema required a search for new ways of data and information flow modelling. The large quantity of components of a power plant unit with its most important components thereby requires a block oriented modelling approach based on lumped and distributed lumped parameters. (orig.)

  2. Modeling and Identification of Multirate Systems

    Institute of Scientific and Technical Information of China (English)

    Feng DING; Tongwen CHEN

    2005-01-01

    Multirate systems are abundant in industry; for example, many soft-sensor design problems are related to modeling, parameter identification, or state estimation involving multirate systems. The study of multirate systems goes back to the early 1950's, and has become an active research area in systems and control. This paper briefly surveys the history of development in the area of multirate systems, and introduces some basic concepts and latest results on multirate systems, including a polynomial transformation technique and the lifting technique as tools for handling multirate systems, lifted state space models, parameter identification of dual-rate systems, how to determine fast single-rate models from dual-rate models and directly from dual-rate data, and a hierarchical identification method for general multirate systems. Finally, some further research topics for multirate systems are given.

  3. Classical investigation of long-range coherence in biological systems

    Science.gov (United States)

    Preto, Jordane

    2016-12-01

    Almost five decades ago, H. Fröhlich [H. Fröhlich, "Long-range coherence and energy storage in biological systems," Int. J. Quantum Chem. 2(5), 641-649 (1968)] reported, on a theoretical basis, that the excitation of quantum modes of vibration in contact with a thermal reservoir may lead to steady states, where under high enough rate of energy supply, only specific low-frequency modes of vibration are strongly excited. This nonlinear phenomenon was predicted to occur in biomolecular systems, which are known to exhibit complex vibrational spectral properties, especially in the terahertz frequency domain. However, since the effects of terahertz or lower-frequency modes are mainly classical at physiological temperatures, there are serious doubts that Fröhlich's quantum description can be applied to predict such a coherent behavior in a biological environment, as suggested by the author. In addition, a quantum formalism makes the phenomenon hard to investigate using realistic molecular dynamics simulations (MD) as they are usually based on the classical principles. In the current paper, we provide a general classical Hamiltonian description of a nonlinear open system composed of many degrees of freedom (biomolecular structure) excited by an external energy source. It is shown that a coherent behaviour similar to Fröhlich's effect is to be expected in the classical case for a given range of parameter values. Thus, the supplied energy is not completely thermalized but stored in a highly ordered fashion. The connection between our Hamiltonian description, carried out in the space of normal modes, and a more standard treatment in the physical space is emphasized in order to facilitate the prediction of the effect from MD simulations. It is shown how such a coherent phenomenon may induce long-range resonance effects that could be of critical importance at the biomolecular level. The present work is motivated by recent experimental evidences of long-lived excited low

  4. On Problems of Multicomponent System Maintenance Modelling

    Institute of Scientific and Technical Information of China (English)

    Tomasz Nowakowski; Sylwia Werbinka

    2009-01-01

    We present an overview of some recent developments in the area of mathematical modeling of maintenance decisions for multi-unit systems. The emphasis is on three main groups of multicomponent maintenance optimization models: the block replacement models, group maintenance models, and opportunistic maintenance models. Moreover, an example of a two-unit system maintenance process is provided in order to compare various maintenance policies.

  5. Microscale methods to investigate and manipulate multispecies biological systems

    Science.gov (United States)

    Fong, Erika Jo

    This thesis details the development of a continuous perfusion platform capable of more closely mimicking in vivo cell-virus dynamics, while surpassing the experimental control and flexibility of standard cell culture. First, a microfluidic flow through acoustic device is optimized to enable efficient and controllable separation of cells and viruses. Repeatable isolation of cell and virus species is demonstrated with both a well-characterized virus, Dengue Virus (DENV), and the novel Golden Gate Virus. Next, a platform is built around this device to enable controllable, automated, continuous cell culture. Beads are used to assess system performance and optimize operation. Subsequently, the platform is used to culture both murine hybridoma (4G2) and human monocyte (THP-1) cell lines for over one month, and demonstrate the ability to manipulate population dynamics. Finally, we use the platform to establish a multispecies culture with THP-1 cells and Sindbis Virus (SINV). This work integrates distinct engineering feats to create a platform capable of enhancing existing cell virus studies and opening the door to a variety of high-impact investigations. (Abstract shortened by ProQuest.).

  6. Traffic Modeling in WCDMA System Level Simulations

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Traffic modeling is a crucial element in WCDMA system level simulations. A clear understanding of the nature of traffic in the WCDMA system and subsequent selection of an appropriate random traffic model are critical to the success of the modeling enterprise. The resultant performances will evidently be of a function that our design has been well adapted to the traffic, channel and user mobility models, and these models are also accurate. In this article, our attention will be focused on modeling voice and WWW data traffic with the SBBP model and Victor model respectively.

  7. USING STRUCTURAL EQUATION MODELING TO INVESTIGATE RELATIONSHIPS AMONG ECOLOGICAL VARIABLES

    Science.gov (United States)

    This paper gives an introductory account of Structural Equation Modeling (SEM) and demonstrates its application using LISRELmodel utilizing environmental data. Using nine EMAP data variables, we analyzed their correlation matrix with an SEM model. The model characterized...

  8. Towards Modelling of Hybrid Systems

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    2006-01-01

    The article is an attempt to use methods of category theory and topology for analysis of hybrid systems. We use the notion of a directed topological space; it is a topological space together with a set of privileged paths. Dynamical systems are examples of directed topological spaces. A hybrid...... system consists of a number of dynamical systems that are glued together according to information encoded in the discrete part of the system. We develop a definition of a hybrid system as a functor from the category generated by a transition system to the category of directed topological spaces. Its...... directed homotopy colimit (geometric realization) is a single directed topological space. The behavior of hybrid systems can be then understood in terms of the behavior of dynamical systems through the directed homotopy colimit....

  9. Investigating mathematical models of immuno-interactions with early-stage cancer under an agent-based modelling perspective

    Science.gov (United States)

    2013-01-01

    Many advances in research regarding immuno-interactions with cancer were developed with the help of ordinary differential equation (ODE) models. These models, however, are not effectively capable of representing problems involving individual localisation, memory and emerging properties, which are common characteristics of cells and molecules of the immune system. Agent-based modelling and simulation is an alternative paradigm to ODE models that overcomes these limitations. In this paper we investigate the potential contribution of agent-based modelling and simulation when compared to ODE modelling and simulation. We seek answers to the following questions: Is it possible to obtain an equivalent agent-based model from the ODE formulation? Do the outcomes differ? Are there any benefits of using one method compared to the other? To answer these questions, we have considered three case studies using established mathematical models of immune interactions with early-stage cancer. These case studies were re-conceptualised under an agent-based perspective and the simulation results were then compared with those from the ODE models. Our results show that it is possible to obtain equivalent agent-based models (i.e. implementing the same mechanisms); the simulation output of both types of models however might differ depending on the attributes of the system to be modelled. In some cases, additional insight from using agent-based modelling was obtained. Overall, we can confirm that agent-based modelling is a useful addition to the tool set of immunologists, as it has extra features that allow for simulations with characteristics that are closer to the biological phenomena. PMID:23734575

  10. Service systems concepts, modeling, and programming

    CERN Document Server

    Cardoso, Jorge; Poels, Geert

    2014-01-01

    This SpringerBrief explores the internal workings of service systems. The authors propose a lightweight semantic model for an effective representation to capture the essence of service systems. Key topics include modeling frameworks, service descriptions and linked data, creating service instances, tool support, and applications in enterprises.Previous books on service system modeling and various streams of scientific developments used an external perspective to describe how systems can be integrated. This brief introduces the concept of white-box service system modeling as an approach to mo

  11. Hydrological modelling in forested systems

    Science.gov (United States)

    This chapter provides a brief overview of forest hydrology modelling approaches for answering important global research and management questions. Many hundreds of hydrological models have been applied globally across multiple decades to represent and predict forest hydrological p...

  12. Investigations and advanced concepts on gyrotron interaction modeling and simulations

    Science.gov (United States)

    Avramidis, K. A.

    2015-12-01

    In gyrotron theory, the interaction between the electron beam and the high frequency electromagnetic field is commonly modeled using the slow variables approach. The slow variables are quantities that vary slowly in time in comparison to the electron cyclotron frequency. They represent the electron momentum and the high frequency field of the resonant TE modes in the gyrotron cavity. For their definition, some reference frequencies need to be introduced. These include the so-called averaging frequency, used to define the slow variable corresponding to the electron momentum, and the carrier frequencies, used to define the slow variables corresponding to the field envelopes of the modes. From the mathematical point of view, the choice of the reference frequencies is, to some extent, arbitrary. However, from the numerical point of view, there are arguments that point toward specific choices, in the sense that these choices are advantageous in terms of simulation speed and accuracy. In this paper, the typical monochromatic gyrotron operation is considered, and the numerical integration of the interaction equations is performed by the trajectory approach, since it is the fastest, and therefore it is the one that is most commonly used. The influence of the choice of the reference frequencies on the interaction simulations is studied using theoretical arguments, as well as numerical simulations. From these investigations, appropriate choices for the values of the reference frequencies are identified. In addition, novel, advanced concepts for the definitions of these frequencies are addressed, and their benefits are demonstrated numerically.

  13. Modeling and Analysis of NGC System using Ptolemy II

    Directory of Open Access Journals (Sweden)

    Archana Sreekumar

    2015-09-01

    Full Text Available Model based system design has been used in real time embedded systems for validating and testing during the development lifecycle. Computation models - synchronous dataflow model (SDF and Discrete Event (DE have been used and finite state machine has been integrated with SDF and Discrete Event (DE modeling domains for simulating the functionalities in the system. Here a case study of resource augmented Navigation, Guidance and Control unit of onboard computers in satellite launch vehicle has been selected as a frame work and fault tolerant algorithm has been modeled and simulated with Ptolemy II. Feasibility of the scheduling of the fault tolerant algorithm has been analyzed and dependencies existing between different components and processes in the system have been investigated. The future work consists of modeling original functionality of NGC units inside each state of FSM and can be validated for the correct performance. Non-deterministic communication and clock drifts can be accounted into the model.

  14. Modeling, Control and Coordination of Helicopter Systems

    CERN Document Server

    Ren, Beibei; Chen, Chang; Fua, Cheng-Heng; Lee, Tong Heng

    2012-01-01

    Modeling, Control and Coordination of Helicopter Systems provides a comprehensive treatment of helicopter systems, ranging from related nonlinear flight dynamic modeling and stability analysis to advanced control design for single helicopter systems, and also covers issues related to the coordination and formation control of multiple helicopter systems to achieve high performance tasks. Ensuring stability in helicopter flight is a challenging problem for nonlinear control design and development. This book is a valuable reference on modeling, control and coordination of helicopter systems,providing readers with practical solutions for the problems that still plague helicopter system design and implementation. Readers will gain a complete picture of helicopters at the systems level, as well as a better understanding of the technical intricacies involved. This book also: Presents a complete picture of modeling, control and coordination for helicopter systems Provides a modeling platform for a general class of ro...

  15. Electronic Education System Model-2

    Science.gov (United States)

    Güllü, Fatih; Kuusik, Rein; Laanpere, Mart

    2015-01-01

    In this study we presented new EES Model-2 extended from EES model for more productive implementation in e-learning process design and modelling in higher education. The most updates were related to uppermost instructional layer. We updated learning processes object of the layer for adaptation of educational process for young and old people,…

  16. Network and adaptive system of systems modeling and analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, Craig R.; Campbell, James E. Dr. (.; .); Anderson, Dennis James; Eddy, John P.

    2007-05-01

    This report documents the results of an LDRD program entitled ''Network and Adaptive System of Systems Modeling and Analysis'' that was conducted during FY 2005 and FY 2006. The purpose of this study was to determine and implement ways to incorporate network communications modeling into existing System of Systems (SoS) modeling capabilities. Current SoS modeling, particularly for the Future Combat Systems (FCS) program, is conducted under the assumption that communication between the various systems is always possible and occurs instantaneously. A more realistic representation of these communications allows for better, more accurate simulation results. The current approach to meeting this objective has been to use existing capabilities to model network hardware reliability and adding capabilities to use that information to model the impact on the sustainment supply chain and operational availability.

  17. Experimental Investigation and Pore-Scale Modeling of Non-Newtonian Fluid Flow in Porous Media

    Science.gov (United States)

    Hauswirth, S.; Dye, A. L.; Miller, C. T.; Tapscott, C.; Schultz, P. B.

    2015-12-01

    Systems involving the flow of non-Newtonian fluids in porous media arise in a number of settings, including hydraulic fracturing, enhanced oil recovery, contaminant remediation, and biological systems. Development of accurate macroscale models of such systems requires an understanding of the relationship between the fluid and medium properties at the microscale and averaged macroscale properties. This study investigates the flow of aqueous solutions of guar gum, a major component of hydraulic fracturing fluids that exhibits Cross model rheological behavior. The rheological properties of solutions containing varying concentrations of guar gum were characterized using a rotational rheometer and the data were fit to a model relating viscosity to shear rate and concentration. Flow experiments were conducted in a porous medium-packed column to measure the pressure response during the flow of guar gum solutions at a wide range of flow rates and determine apparent macroscale viscosities and shear rates. To investigate the relationship between the fluid rheology, microscale physics, and the observed macroscale properties, a lattice Boltzmann pore scale simulator incorporating non-Newtonian behavior was developed. The model was validated, then used to simulate systems representative of the column experiments, allowing direct correlation of detailed microscale physics to the macroscale observations.

  18. On Verification Modelling of Embedded Systems

    NARCIS (Netherlands)

    Brinksma, Ed; Mader, Angelika

    2004-01-01

    Computer-aided verification of embedded systems hinges on the availability of good verification models of the systems at hand. Such models must be much simpler than full design models or specifications to be of practical value, because of the unavoidable combinatorial complexities in the verificatio

  19. Applying Modeling Tools to Ground System Procedures

    Science.gov (United States)

    Di Pasquale, Peter

    2012-01-01

    As part of a long-term effort to revitalize the Ground Systems (GS) Engineering Section practices, Systems Modeling Language (SysML) and Business Process Model and Notation (BPMN) have been used to model existing GS products and the procedures GS engineers use to produce them.

  20. Investigation of TMA systems with different freeform surfaces

    Science.gov (United States)

    Zhong, Y.; Gross, H.; Broemel, A.; Kirschstein, S.; Petruck, P.; Tuennermann, A.

    2015-09-01

    Three mirror anastigmats (TMA) are telescopic optical systems with only plane symmetry, that allow for good image quality without any central obscuration. The complexities of manufacturing and alignment can be reduced by fabricating the first mirror and the third mirror in one piece and defining a common axis of all the mirrors. It is attractive to use off-axis used aspheres and to come to an acceptable performance with the smallest number of freeform surfaces. In this paper, different types of freeform surfaces are considered to evaluate their potential. In the performed case study, the correction of spherical aberration and coma is best corrected in the pupil with the second mirror and to select the Zernike representation with remaining x-symmetry is one of the best ways to do this. The use of the Chebyshev polynomials also gives good results. Furthermore it is found, that the first mirror and the third mirror are quite beneficial to be modelled as off-axis aspheres of the Q-type. The result shows that a combination of two Q-aspheres with a Zernike surface at the second mirror is one of the most favorable combinations.

  1. Investigation of Effectiveness of Order Review and Release Models in Make to Order Supply Chain

    Directory of Open Access Journals (Sweden)

    Kundu Kaustav

    2016-01-01

    Full Text Available Nowadays customisation becomes more common due to vast requirement from the customers for which industries are trying to use make-to-order (MTO strategy. Due to high variation in the process, workload control models are extensively used for jobshop companies which usually adapt MTO strategy. Some authors tried to implement workload control models, order review and release systems, in non-repetitive manufacturing companies, where there is a dominant flow in production. Those models are better in shop floor but their performances are never been investigated in high variation situations like MTO supply chain. This paper starts with the introduction of particular issues in MTO companies and a general overview of order review and release systems widely used in the industries. Two order review and release systems, the Limited and Balanced models, particularly suitable for flow shop system are applied to MTO supply chain, where the processing times are difficult to estimate due to high variation. Simulation results show that the Balanced model performs much better than the Limited model if the processing times can be estimated preciously.

  2. A Mathematical Model of the Human Respiratory Control System

    Science.gov (United States)

    Milhorn, Howard T.; Benton, Richard; Ross, Richard; Guyton, Arthur C.

    1965-01-01

    The respiratory system exhibits the properties of a control system of the regulator type. Equations describing this biological control system have been derived. Transient and steady-state solutions for various CO2 and O2 step input disturbances were obtained utilizing a digital computer and are compared with experimental results. The effectiveness of the respiratory system as a regulator is investigated. Further extensions of the model are suggested. PMID:14284328

  3. Research on models of biological systems that can be integrated into mechatronic systems

    Science.gov (United States)

    Pop, P. P.; Pop-Vadean, A.; Barz, C.; Latinovic, T.; Chiver, O.

    2016-02-01

    The models of biological systems that we find on Earth can be the subject of research to develop a few mechatronic systems. Such models are offered by bees, ants, crows, cranes, etc. Article aims to investigate these models and their manifestations. Imitating this behavior and studied him offer ideas for develop models that can be integrated into mechatronic systems. They can be integrated into mechatronic system as algorithms for finding local optimum, to search, to detect an optimal way travel on a network, to find best decision, etc.

  4. EXPOSURE ANALYSIS MODELING SYSTEM (EXAMS): USER MANUAL AND SYSTEM DOCUMENTATION

    Science.gov (United States)

    The Exposure Analysis Modeling System, first published in 1982 (EPA-600/3-82-023), provides interactive computer software for formulating aquatic ecosystem models and rapidly evaluating the fate, transport, and exposure concentrations of synthetic organic chemicals - pesticides, ...

  5. Preliminary investigation of dose for a dedicated mammotomography system

    Science.gov (United States)

    McKinley, Randolph L.; Tornai, Martin P.

    2006-03-01

    We use a previously reported, optimized quasi-monochromatic beam technique together with unique complex acquisition trajectories made possible with a novel, dedicated cone-beam transmission computed mammotomography (CmT) system to investigate effects of low dose imaging of pendant, uncompressed breasts. Investigators have used a guideline of dose for CmT type applications as that used for dual-view mammography (4-6 mGy for average breast size). This dose is somewhat arbitrary, and it may be possible to reduce this significantly without sacrificing image quality using our quasi-monochromatic x-ray beam, 3D complex acquisition orbits, and iterative reconstruction techniques. A low-scatter acrylic resolution phantom in various media, a breast phantom with sponge and oil-filled lesions, and a cadaver breast are used to evaluate the effect of lowered dose on resolution and image artifacts. Complex saddle acquisition trajectories (necessary to overcome cone-beam distortion) are carried out for total exposures of 96, 300, and 600 mAs over 240 projections. These exposures relate approximately to 1/10 th, 1/3 rd, and 2/3 rd of the standard dual view mammography dose for an average sized 50% adipose/glandular breast. Iterative reconstruction uses an OSTR algorithm with 0.125 mm 3 voxels. Image artifacts increased as dose was reduced but did not appear to greatly degrade image quality except at the lowest contrast tested (1% absolute contrast). As expected, noise increased as dose was reduced. However, this did not appear to affect resolution for rods in air (high contrast), nor rods in oil (20% absolute contrast). Resolution was reduced for rods in water (1% absolute contrast) due to increased prevalence of image artifacts as well as increased noise. Breast phantom imaging of soft lesions in a highly glandular breast (6% absolute contrast) clearly yielded the 60uL and all larger volume lesions. Preliminary biological breast tissue results illustrate excellent subjective

  6. FINESSE: Field Investigations to Enable Solar System Science and Exploration

    Science.gov (United States)

    Heldmann, Jennifer; Lim, Darlene; Colaprete, Anthony

    2015-01-01

    The FINESSE (Field Investigations to Enable Solar System Science and Exploration) team is focused on a science and exploration field-based research program aimed at generating strategic knowledge in preparation for the human and robotic exploration of the Moon, near-Earth asteroids (NEAs) and Phobos and Deimos. We follow the philosophy that "science enables exploration and exploration enables science." 1) FINESSE Science: Understand the effects of volcanism and impacts as dominant planetary processes on the Moon, NEAs, and Phobos & Deimos. 2) FINESSE Exploration: Understand which exploration concepts of operations (ConOps) and capabilities enable and enhance scientific return. To accomplish these objectives, we are conducting an integrated research program focused on scientifically-driven field exploration at Craters of the Moon National Monument and Preserve in Idaho and at the West Clearwater Lake Impact Structure in northern Canada. Field deployments aimed at reconnaissance geology and data acquisition were conducted in 2014 at Craters of the Moon National Monument and Preserve. Targets for data acquisition included selected sites at Kings Bowl eruptive fissure, lava field and blowout crater, Inferno Chasm vent and outflow channel, North Crater lava flow and Highway lava flow. Field investigation included (1) differential GPS (dGPS) measurements of lava flows, channels (and ejecta block at Kings Bowl); (2) LiDAR imaging of lava flow margins, surfaces and other selected features; (3) digital photographic documentation; (4) sampling for geochemical and petrographic analysis; (5) UAV aerial imagery of Kings Bowl and Inferno Chasm features; and (6) geologic assessment of targets and potential new targets. Over the course of the 5-week field FINESSE campaign to the West Clearwater Impact Structure (WCIS) in 2014, the team focused on several WCIS research topics, including impactites, central uplift formation, the impact-generated hydrothermal system, multichronometer

  7. Pǎun's systems as models of economic systems

    Institute of Scientific and Technical Information of China (English)

    Waldemar Korczynski

    2007-01-01

    In the paper a concept for modeling the economic systems by the formalism of Pǎun's systems is proposed. The main idea is to represent economic systems as homomorphic images of Petri nets corresponding to the (super) cells of Pǎun's systems.

  8. Coupling geophysical investigation with hydrothermal modeling to constrain the enthalpy classification of a potential geothermal resource.

    Science.gov (United States)

    White, Jeremy T.; Karakhanian, Arkadi; Connor, Chuck; Connor, Laura; Hughes, Joseph D.; Malservisi, Rocco; Wetmore, Paul

    2015-01-01

    An appreciable challenge in volcanology and geothermal resource development is to understand the relationships between volcanic systems and low-enthalpy geothermal resources. The enthalpy of an undeveloped geothermal resource in the Karckar region of Armenia is investigated by coupling geophysical and hydrothermal modeling. The results of 3-dimensional inversion of gravity data provide key inputs into a hydrothermal circulation model of the system and associated hot springs, which is used to evaluate possible geothermal system configurations. Hydraulic and thermal properties are specified using maximum a priori estimates. Limited constraints provided by temperature data collected from an existing down-gradient borehole indicate that the geothermal system can most likely be classified as low-enthalpy and liquid dominated. We find the heat source for the system is likely cooling quartz monzonite intrusions in the shallow subsurface and that meteoric recharge in the pull-apart basin circulates to depth, rises along basin-bounding faults and discharges at the hot springs. While other combinations of subsurface properties and geothermal system configurations may fit the temperature distribution equally well, we demonstrate that the low-enthalpy system is reasonably explained based largely on interpretation of surface geophysical data and relatively simple models.

  9. Intersymbol Interference Investigations Using a 3D Time-Dependent Traveling Wave Tube Model

    Science.gov (United States)

    Kory, Carol L.; Andro, Monty

    2002-01-01

    For the first time, a time-dependent, physics-based computational model has been used to provide a direct description of the effects of the traveling wave tube amplifier (TWTA) on modulated digital signals. The TWT model comprehensively takes into account the effects of frequency dependent AM/AM and AM/PM conversion; gain and phase ripple; drive-induced oscillations; harmonic generation; intermodulation products; and backward waves. Thus, signal integrity can be investigated in the presence of these sources of potential distortion as a function of the physical geometry and operating characteristics of the high power amplifier and the operational digital signal. This method promises superior predictive fidelity compared to methods using TWT models based on swept- amplitude and/or swept-frequency data. First, the TWT model using the three dimensional (3D) electromagnetic code MAFIA is presented. Then, this comprehensive model is used to investigate approximations made in conventional TWT black-box models used in communication system level simulations. To quantitatively demonstrate the effects these approximations have on digital signal performance predictions, including intersymbol interference (ISI), the MAFIA results are compared to the system level analysis tool, Signal Processing Workstation (SPW), using high order modulation schemes including 16 and 64-QAM.

  10. Intersymbol Interference Investigations Using a 3D Time-Dependent Traveling Wave Tube Model

    Science.gov (United States)

    Kory, Carol L.; Andro, Monty

    2002-01-01

    For the first time, a time-dependent, physics-based computational model has been used to provide a direct description of the effects of the traveling wave tube amplifier (TWTA) on modulated digital signals. The TWT model comprehensively takes into account the effects of frequency dependent AM/AM and AM/PM conversion; gain and phase ripple; drive-induced oscillations; harmonic generation; intermodulation products; and backward waves. Thus, signal integrity can be investigated in the presence of these sources of potential distortion as a function of the physical geometry and operating characteristics of the high power amplifier and the operational digital signal. This method promises superior predictive fidelity compared to methods using TWT models based on swept- amplitude and/or swept-frequency data. First, the TWT model using the three dimensional (3D) electromagnetic code MAFIA is presented. Then, this comprehensive model is used to investigate approximations made in conventional TWT black-box models used in communication system level simulations. To quantitatively demonstrate the effects these approximations have on digital signal performance predictions, including intersymbol interference (ISI), the MAFIA results are compared to the system level analysis tool, Signal Processing Workstation (SPW), using high order modulation schemes including 16 and 64-QAM.

  11. Modeling Control Situations in Power System Operations

    DEFF Research Database (Denmark)

    Saleem, Arshad; Lind, Morten; Singh, Sri Niwas

    2010-01-01

    Increased interconnection and loading of the power system along with deregulation has brought new challenges for electric power system operation, control and automation. Traditional power system models used in intelligent operation and control are highly dependent on the task purpose. Thus, a model...... for intelligent operation and control must represent system features, so that information from measurements can be related to possible system states and to control actions. These general modeling requirements are well understood, but it is, in general, difficult to translate them into a model because of the lack...... of explicit principles for model construction. This paper presents a work on using explicit means-ends model based reasoning about complex control situations which results in maintaining consistent perspectives and selecting appropriate control action for goal driven agents. An example of power system...

  12. Modeling Control Situations in Power System Operations

    DEFF Research Database (Denmark)

    Saleem, Arshad; Lind, Morten; Singh, Sri Niwas

    2010-01-01

    Increased interconnection and loading of the power system along with deregulation has brought new challenges for electric power system operation, control and automation. Traditional power system models used in intelligent operation and control are highly dependent on the task purpose. Thus, a model...... for intelligent operation and control must represent system features, so that information from measurements can be related to possible system states and to control actions. These general modeling requirements are well understood, but it is, in general, difficult to translate them into a model because of the lack...... of explicit principles for model construction. This paper presents a work on using explicit means-ends model based reasoning about complex control situations which results in maintaining consistent perspectives and selecting appropriate control action for goal driven agents. An example of power system...

  13. Modelling the behavior of systems : Basic concepts and algorithms

    NARCIS (Netherlands)

    Cotroneo, T; Willems, JC; Powell, MJD; Scholtes, S

    2000-01-01

    In this paper we introduce the behavioral approach as a mathematical language for describing dynamical systems, in particular systems modeled by high order constant coefficient linear differential equations. We investigate what data have to be added in order to express the influence of the environme

  14. Modelling the behavior of systems : Basic concepts and algorithms

    NARCIS (Netherlands)

    Cotroneo, T; Willems, JC; Powell, MJD; Scholtes, S

    2000-01-01

    In this paper we introduce the behavioral approach as a mathematical language for describing dynamical systems, in particular systems modeled by high order constant coefficient linear differential equations. We investigate what data have to be added in order to express the influence of the

  15. Towards a community Earth System Model

    Science.gov (United States)

    Blackmon, M.

    2003-04-01

    The Community Climate System Model, version 2 (CCSM2), was released in June 2002. CCSM2 has several new components and features, which I will discuss briefly. I will also show a few results from a multi-century equilibrium run with this model, emphasizing the improvements over the earlier simulation using the original CSM. A few flaws and inadequacies in CCSM2 have been identified. I will also discuss briefly work underway to improve the model and present results, if available. CCSM2, with improvements, will be the basis for the development of a Community Earth System Model (CESM). The highest priority for expansion of the model involves incorporation of biogeosciences into the coupled model system, with emphasis given to the carbon, nitrogen and iron cycles. The overall goal of the biogeosciences project within CESM is to understand the regulation of planetary energetics, planetary ecology, and planetary metabolism through exchanges of energy, momentum, and materials among atmosphere, land, and ocean, and the response of the climate system through these processes to changes in land cover and land use. In particular, this research addresses how biogeochemical coupling of carbon, nitrogen, and iron cycles affects climate and how human perturbations of these cycles alter climate. To accomplish these goals, the Community Land Model, the land component of CCSM2, is being developed to include river routing, carbon and nitrogen cycles, emissions of mineral aerosols and biogenic volatile organic compounds, dry deposition of various gases, and vegetation dynamics. The carbon and nitrogen cycles are being implemented using parameterizations developed as part of a state-of-the-art ecosystem biogeochemistry model. The primary goal of this research is to provide an accurate net flux of CO2 between the land and the atmosphere so that CESM can be used to study the dynamics of the coupled climate-carbon system. Emissions of biogenic volatile organic compounds are also based on a

  16. Modeling noisy resonant system response

    Science.gov (United States)

    Weber, Patrick Thomas; Walrath, David Edwin

    2017-02-01

    In this paper, a theory-based model replicating empirical acoustic resonant signals is presented and studied to understand sources of noise present in acoustic signals. Statistical properties of empirical signals are quantified and a noise amplitude parameter, which models frequency and amplitude-based noise, is created, defined, and presented. This theory-driven model isolates each phenomenon and allows for parameters to be independently studied. Using seven independent degrees of freedom, this model will accurately reproduce qualitative and quantitative properties measured from laboratory data. Results are presented and demonstrate success in replicating qualitative and quantitative properties of experimental data.

  17. Generic Model Host System Design

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Chungming; /SLAC; Wu, Juhao; /SLAC; Qiang, Ji; /LBL, Berkeley; Shen, Guobao; /Brookhaven

    2012-06-22

    There are many simulation codes for accelerator modelling; each one has some strength but not all. A platform which can host multiple modelling tools would be ideal for various purposes. The model platform along with infrastructure support can be used not only for online applications but also for offline purposes. Collaboration is formed for the effort of providing such a platform. In order to achieve such a platform, a set of common physics data structure has to be set. Application Programming Interface (API) for physics applications should also be defined within a model data provider. A preliminary platform design and prototype is discussed.

  18. Model based investigation of the potential lactate recovery using Electro-Enhanced Dialysis - Static analysis

    DEFF Research Database (Denmark)

    Prado Rubio, Oscar Andres; Jørgensen, Sten Bay; Jonsson, Gunnar Eigil

    2011-01-01

    The competitive ion transport through anion exchange membranes under current load conditions, referred to as the electro-enhanced dialysis process, is modeled and investigated through simulations. A dynamic model has been developed for simultaneous transport of multiple ions based on the Nernst......–Plank equation. This model accounts for the convective transport of the dissociated and undissociated species in the module channels, and the diffusion and migration across the boundary layers and membranes. The potential static flux enhancement is evaluated and compared to Donnan dialysis operation for lactate...... recovery, where lactate fluxes were increased up to 230%. The effect of the imposed current on the concentration profiles is analyzed. Furthermore, the current saturation condition is investigated for the proposed electro-enhanced dialysis system. Thus, the operating window for current density and inlet...

  19. Four MATLAB-Simulink models ofphotovoltaic system

    Directory of Open Access Journals (Sweden)

    Jawad Radhi Mahmood, Nasir Hussein Selman

    2016-01-01

    Full Text Available This paper presents four different MATLAB models to simulate the output I-V and P-V characteristics of photovoltaic (PV cells or systems. All of the models are implemented with Matlab-Simulink. Detailed modeling procedure for one-diode equivalent circuit model with all equations and numerical values is presented. The parameters required for the modeling have been taken from manufacturer's datasheet for 240W SOLIMPEKS solar panel. I-V and P-V characteristics of a typical 1.92 kW PV system have been simulated using the proposed models. The simulation took into account the sunlight insolation and temperature effect. Results of the models are validated with I-V and P-V curves provided by the manufacturer(s. The proposed models are very useful for those interested in working in the field of solar systems because they emulate and analyze the characteristics of all the solar systems easily.

  20. CTL Model Update for System Modifications

    CERN Document Server

    Ding, Yulin; Zhang, Yan; Zhang, Y; 10.1613/jair.2420

    2011-01-01

    Model checking is a promising technology, which has been applied for verification of many hardware and software systems. In this paper, we introduce the concept of model update towards the development of an automatic system modification tool that extends model checking functions. We define primitive update operations on the models of Computation Tree Logic (CTL) and formalize the principle of minimal change for CTL model update. These primitive update operations, together with the underlying minimal change principle, serve as the foundation for CTL model update. Essential semantic and computational characterizations are provided for our CTL model update approach. We then describe a formal algorithm that implements this approach. We also illustrate two case studies of CTL model updates for the well-known microwave oven example and the Andrew File System 1, from which we further propose a method to optimize the update results in complex system modifications.

  1. Numerical investigation into the existence of limit cycles in two-dimensional predator�prey systems

    Directory of Open Access Journals (Sweden)

    Quay van der Hoff

    2013-05-01

    Full Text Available There has been a surge of interest in developing and analysing models of interacting species in ecosystems, with specific interest in investigating the existence of limit cycles in systems describing the dynamics of these species. The original Lotka–Volterra model does not possess any limit cycles. In recent years this model has been modified to take disturbances into consideration and allow populations to return to their original numbers. By introducing logistic growth and a Holling Type II functional response to the traditional Lotka–Volterra-type models, it has been proven analytically that a unique, stable limit cycle exists. These proofs make use of Dulac functions, Liénard equations and invariant regions, relying on theory developed by Poincaré, Poincaré-Bendixson, Dulac and Liénard, and are generally perceived as difficult. Computer algebra systems are ideally suited to apply numerical methods to confirm or refute the analytical findings with respect to the existence of limit cycles in non-linear systems. In this paper a class of predator–prey models of a Gause type is used as the vehicle to illustrate the use of a simple, yet novel numerical algorithm. This algorithm confirms graphically the existence of at least one limit cycle that has analytically been proven to exist. Furthermore, adapted versions of the proposed algorithm may be applied to dynamic systems where it is difficult, if not impossible, to prove analytically the existence of limit cycles.

  2. An empirical investigation of two competing models of patient satisfaction.

    Science.gov (United States)

    Mishra, D P; Singh, J; Wood, V

    1991-01-01

    This paper empirically examines two competing models of patient satisfaction. Specifically, a five factor SERVQUAL model proposed by Parasuraman et al. (1988) and a tripartite model posited by Smith, Bloom, and Davis (1986) are examined. The two models are tested via factor analysis based on data collected from a field survey of hospital patients. The results of this study indicate that the five dimensional SERVQUAL model is not supported by data. On the other hand, there is general support for the tripartite model. Implications of our results for health care practitioners and researchers are discussed. Future directions for research are also outlined.

  3. Bedrock Hydrogeology - Groundwater flow modelling. Site investigation SFR

    Energy Technology Data Exchange (ETDEWEB)

    Oehman, Johan [Geosigma AB, Uppsala (Sweden); Follin, Sven [SF GeoLogic AB, Taeby (Sweden); Oden, Magnus [SKB, Stockholm (Sweden)

    2013-05-15

    The hydrogeological model developed for the SFR extension project (PSU) consists of 40 geologically modelled deformation zones (DZ) and 8 sub-horizontal structural-hydraulic features, called SBAstructures, not defined in the geological model. However, some of the SBA-structures coincide with what is defined as unresolved possible deformation zones (Unresolved PDZ) in the geological modelling. In addition, the hydrogeological model consists of a stochastic discrete fracture network (DFN) model intended for the less fractured rock mass volumes (fracture domains) between the zones and the SBA-structures, and a stochastic fracture model intended to handle remaining Unresolved PDZs in the geological modelling not modelled as SBA-structures in the hydrogeological modelling. The four structural components of the bedrock in the hydrogeological model, i.e. DZ, SBA, Unresolved PDZ and DFN, are assigned hydraulic properties in the hydrogeological model based on the transmissivities interpreted from single-hole hydraulic tests. The main objective of the present work is to present the characteristics of the hydrogeological model with regard to the needs of the forthcoming safety assessment SR-PSU. In concrete words, simulated data are compared with measured data, i.e. hydraulic heads in boreholes and tunnel inflow to the existing repository (SFR). The calculations suggest that the available data for flow model calibration cannot be used to motivate a substantial adjustment of the initial hydraulic parameterisation (assignment of hydraulic properties) of the hydrogeological model. It is suggested that uncertainties in the hydrogeological model are studied in the safety assessment SR-PSU by means of a large number of calculation cases. These should address hydraulic heterogeneity of deterministic structures (DZ and SBA) and realisations of stochastic fractures/fracture networks (Unresolved PDZ and DFN) within the entire SFR Regional model domain.

  4. Using the multi-living agent concept to investigate complex information systems

    Institute of Scientific and Technical Information of China (English)

    WANG Yue; TAO Ran; LI BingZhao

    2009-01-01

    In this paper, we propose the multi-living agent (MLA) concept based on the of analysis the characteristics of complex information systems, especially those systems that require multi-functional operations under strict restraint strong countermeasures (SRSC) environment. First, we investigate the representation of the livelihood of the system under the SRSC conditions, and obtain the basic dynamical presentation of the MLA from the profile of the system's function. Next, we propose the concept of the living self-organization based on the self-organization profile of the system, and derive a Two-Set model of the living self-organization mechanism. Further, based on the above results, we present a basic construction model of MLA-based information systems in the field of information security and countermeasures. A three-level negotiation-coordination mechanism is also derived. Finally, we present two practical examples to show how to use the MLA concept to analyze and study real complex information systems. In our opinion, the proposal of the MLA will bridge the gap between the research of the application and the basic application level of science. It provides the principle research methods and the supporting theories for the construction and analysis of complex information systems in the information security and countermeasures field.

  5. Investigation of longitudinal control system for a small hydrofoil boat

    Science.gov (United States)

    Phillips, W. H.; Shaughnessy, J. D.

    1976-01-01

    An analysis of a hydromechanical system for longitudinal control of a small hydrofoil boat is presented. The system incorporates height and acceleration sensors operating flaps on the foils through a mechanical linkage. Effects of some of the system parameters on the stability and response to waves are shown. The results indicate that the system is capable of providing adequate stability, but the response to stern waves at low frequencies is larger than desired.

  6. Investigating conceptual models for physical property couplings in solid solution models of cement

    Energy Technology Data Exchange (ETDEWEB)

    Benbow, Steven; Watson, Claire; Savage, David [Quintesssa Ltd., Henley-on-Thames (United Kingdom)

    2005-11-15

    The long-term behaviour of cementitious engineered barriers is an important process to consider when modelling the migration of radionuclides from a geological repository for nuclear waste. The modelling of cement is complicated by the fact that the cement is dominated by the behaviour of calcium silicate hydrate (CSH) gel which is a complex solid exhibiting incongruent dissolution behaviour. In this report, we have demonstrated the implementation of a solid-solution CSH gel model within a geochemical transport modelling framework using the Raiden computer code to investigate cement/concrete-groundwater interactions. The modelling conducted here shows that it is possible to couple various conceptual models for the evolution of physical properties of concrete with a solid solution model for cement degradation in a fully coupled geochemical transport model to describe the interaction of cement/concrete engineered barriers with groundwater. The results show that changes to the conceptual models and flow rates can give rise to very different evolutions. Most simulations were carried out at a reduced 'experimental' scale rather than full repository scale. The work has shown the possibility to investigate also the changing physical properties of degrading cement. To further develop the model more emphasis is needed on kinetics and the detailed development of a nearly clogged pore space. Modelling of the full repository scale could be another way forward to understand the behaviour of degrading concrete. A general conclusion is that the combined effects of chemical evolution and physical degradation should be analysed in performance assessments of cementitious repositories. Moreover, the project results will be used as one basis in coming reviews of SKB's safety assessments of repositories for spent fuel and low-and intermediate level waste.

  7. Computational Models for Nonlinear Aeroelastic Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Clear Science Corp. and Duke University propose to develop and demonstrate new and efficient computational methods of modeling nonlinear aeroelastic systems. The...

  8. Model Updating Nonlinear System Identification Toolbox Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ZONA Technology (ZONA) proposes to develop an enhanced model updating nonlinear system identification (MUNSID) methodology that utilizes flight data with...

  9. Modeling and analysis of biomass production systems

    Energy Technology Data Exchange (ETDEWEB)

    Mishoe, J.W.; Lorber, M.N.; Peart, R.M.; Fluck, R.C.; Jones, J.W.

    1984-01-01

    BIOMET is an interactive simulation model that is used to analyze specific biomass and methane production systems. The system model is composed of crop growth models, harvesting, transportation, conversion and economic submodels. By use of menus the users can configure the structure and set selected parameters of the system to analyze the effects of variables within the component models. For example, simulations of a water hyacinth system resulted in yields of 63, 48 and 37 mg/ha/year for different harvest schedules. For napier grass, unit methane costs were $3.04, $2.86 and $2.98 for various yields of biomass. 10 references.

  10. Error Propagation in a System Model

    Science.gov (United States)

    Schloegel, Kirk (Inventor); Bhatt, Devesh (Inventor); Oglesby, David V. (Inventor); Madl, Gabor (Inventor)

    2015-01-01

    Embodiments of the present subject matter can enable the analysis of signal value errors for system models. In an example, signal value errors can be propagated through the functional blocks of a system model to analyze possible effects as the signal value errors impact incident functional blocks. This propagation of the errors can be applicable to many models of computation including avionics models, synchronous data flow, and Kahn process networks.

  11. Systems biology approaches and pathway tools for investigating cardiovascular disease

    NARCIS (Netherlands)

    Wheelock, C.E.; Wheelock, A.M.; Kawashima, S.; Diez, D.; Kanehisa, M.; Erk, M. van; Kleemann, R.; Haeggström, J.Z.; Goto, S.

    2009-01-01

    Systems biology aims to understand the nonlinear interactions of multiple biomolecular components that characterize a living organism. One important aspect of systems biology approaches is to identify the biological pathways or networks that connect the differing elements of a system, and examine ho

  12. Hydrological modeling in forested systems

    Science.gov (United States)

    H.E. Golden; G.R. Evenson; S. Tian; Devendra Amatya; Ge Sun

    2015-01-01

    Characterizing and quantifying interactions among components of the forest hydrological cycle is complex and usually requires a combination of field monitoring and modelling approaches (Weiler and McDonnell, 2004; National Research Council, 2008). Models are important tools for testing hypotheses, understanding hydrological processes and synthesizing experimental data...

  13. Stochastic Modelling of Energy Systems

    DEFF Research Database (Denmark)

    Andersen, Klaus Kaae

    2001-01-01

    equations are expressed in terms of stochastic differential equations. From a theoretical viewpoint the techniques for experimental design, parameter estimation and model validation are considered. From the practical viewpoint emphasis is put on how this methods can be used to construct models adequate...

  14. Stochastic Modelling of Hydrologic Systems

    DEFF Research Database (Denmark)

    Jonsdottir, Harpa

    2007-01-01

    In this PhD project several stochastic modelling methods are studied and applied on various subjects in hydrology. The research was prepared at Informatics and Mathematical Modelling at the Technical University of Denmark. The thesis is divided into two parts. The first part contains an introduct......In this PhD project several stochastic modelling methods are studied and applied on various subjects in hydrology. The research was prepared at Informatics and Mathematical Modelling at the Technical University of Denmark. The thesis is divided into two parts. The first part contains...... an introduction and an overview of the papers published. Then an introduction to basic concepts in hydrology along with a description of hydrological data is given. Finally an introduction to stochastic modelling is given. The second part contains the research papers. In the research papers the stochastic methods...

  15. Hypervirial Models of Stellar Systems

    CERN Document Server

    Evans, N W

    2005-01-01

    A family of cusped potential-density pairs is introduced for modelling galaxies and dark haloes. The density profile is cusped like 1/r^(2-p) at small radii. The distribution function takes the simple form L^(p-2) E^([3p+1]/2) (where E is the binding energy and L is the angular momentum). The models all possess the remarkable property that the virial theorem holds locally, from which they earn their name as the hypervirial family. Famously, this property was first discovered by Eddington to hold for the Plummer model in 1916. In fact, the seductive properties of the Plummer model extend to the whole hypervirial family, including the members possessing the cosmologically important cusps with density behaving like 1/r or 1/r^1.5 or 1/r^1.33. The intrinsic and projected properties of the family of models are discussed in some detail.

  16. Semantic models for adaptive interactive systems

    CERN Document Server

    Hussein, Tim; Lukosch, Stephan; Ziegler, Jürgen; Calvary, Gaëlle

    2013-01-01

    Providing insights into methodologies for designing adaptive systems based on semantic data, and introducing semantic models that can be used for building interactive systems, this book showcases many of the applications made possible by the use of semantic models.Ontologies may enhance the functional coverage of an interactive system as well as its visualization and interaction capabilities in various ways. Semantic models can also contribute to bridging gaps; for example, between user models, context-aware interfaces, and model-driven UI generation. There is considerable potential for using

  17. MODELLING OF BACTERIAL SULPHATE REDUCTION IN ANAEROBIC PONDS : KINETIC INVESTIGATIONS

    OpenAIRE

    Harerimana, Casimir; Vasel, Jean-Luc; Jupsin, Hugues; Ouali, Amira

    2011-01-01

    The aim of the study was first to develop a simple and practical model of anaerobic digestion including sulphate-reduction in anaerobic ponds. The basic microbiology of our model consists of three steps, namely, acidogenesis, methanogenesis, and sulphate reduction. This model includes multiple reaction stoichiometry and substrate utilization kinetics. The second aim was to determine some kinetic parameters associated with this model. The values of these parameters for sulfidogenic bacteria ar...

  18. Investigating the appropriate level of complexity for stormwater micropollutants modelling

    DEFF Research Database (Denmark)

    Vezzaro, Luca; Mikkelsen, Peter Steen

    2011-01-01

    The increasing importance of stormwater micropollutants (MP) management boosted the use of mathematical models in this field. Several approaches with different level of spatial and temporal resolution have been applied in the last years. This study compared modelling approaches differing for thei......The increasing importance of stormwater micropollutants (MP) management boosted the use of mathematical models in this field. Several approaches with different level of spatial and temporal resolution have been applied in the last years. This study compared modelling approaches differing...

  19. Experimental investigation and modeling of diesel engine fuel spray

    OpenAIRE

    Kolodnytska, R. V.; Karimi, K; Crua, C.; Heikal, M. R.; Sazhina, E. M.

    2008-01-01

    A model for spray penetration in diesel engines is suggested. It is based on momentum conservation for a realistic mass flow rate transient profile. The modelling approach is based on tracking of centre-of-fuel-mass (COFM) of injected diesel fuel. The model was validated for Bosch and Delphi injectors using the data obtained at Sir Harry Ricardo automotive centre, University of Brighton, UK. The model is shown to produce a good agreement with the experimental data until ...

  20. Model reduction of linear conservative mechanical systems

    NARCIS (Netherlands)

    Schaft, van der A.J.; Oeloff, J.E.

    1990-01-01

    An approach for model reduction of linear conservative or weakly damped mechanical systems is proposed. It is based on the balancing of an associated gradient system. It uses the joint knowledge of the system matrix and the input and output matrices of the Hamiltonian system. The key idea is to asso

  1. The Terrestrial Investigation Model: A probabilistic risk assessment model for birds exposed to pesticides

    Science.gov (United States)

    One of the major recommendations of the National Academy of Science to the USEPA, NMFS and USFWS was to utilize probabilistic methods when assessing the risks of pesticides to federally listed endangered and threatened species. The Terrestrial Investigation Model (TIM, version 3....

  2. Modeling complex work systems - method meets reality

    OpenAIRE

    Veer, van der, C.G.; Hoeve, Machteld; Lenting, Bert F.

    1996-01-01

    Modeling an existing task situation is often a first phase in the (re)design of information systems. For complex systems design, this model should consider both the people and the organization involved, the work, and situational aspects. Groupware Task Analysis (GTA) as part of a method for the design of complex systems, has been applied in a situation of redesign of a Dutch public administration system. The most feasible method to collect information in this case was ethnography, the resulti...

  3. Modeling of power electronic systems with EMTP

    Science.gov (United States)

    Tam, Kwa-Sur; Dravid, Narayan V.

    1989-01-01

    In view of the potential impact of power electronics on power systems, there is need for a computer modeling/analysis tool to perform simulation studies on power systems with power electronic components as well as to educate engineering students about such systems. The modeling of the major power electronic components of the NASA Space Station Freedom Electric Power System is described along with ElectroMagnetic Transients Program (EMTP) and it is demonstrated that EMTP can serve as a very useful tool for teaching, design, analysis, and research in the area of power systems with power electronic components. EMTP modeling of power electronic circuits is described and simulation results are presented.

  4. Models of the venous system

    DEFF Research Database (Denmark)

    Mehlsen, J

    2000-01-01

    of the venous system require at least three elements: a resistor, a capacitor and an inductor, with the latter being of more importance in the venous than in the arterial system. Non-linearities must be considered in pressure/flow relations in the small venules, during venous collapse, or low flow conditions...

  5. Planetary subsurface investigation by 3D visualization model .

    Science.gov (United States)

    Seu, R.; Catallo, C.; Tragni, M.; Abbattista, C.; Cinquepalmi, L.

    Subsurface data analysis and visualization represents one of the main aspect in Planetary Observation (i.e. search for water or geological characterization). The data are collected by subsurface sounding radars as instruments on-board of deep space missions. These data are generally represented as 2D radargrams in the perspective of space track and z axes (perpendicular to the subsurface) but without direct correlation to other data acquisition or knowledge on the planet . In many case there are plenty of data from other sensors of the same mission, or other ones, with high continuity in time and in space and specially around the scientific sites of interest (i.e. candidate landing areas or particular scientific interesting sites). The 2D perspective is good to analyse single acquisitions and to perform detailed analysis on the returned echo but are quite useless to compare very large dataset as now are available on many planets and moons of solar system. The best way is to approach the analysis on 3D visualization model generated from the entire stack of data. First of all this approach allows to navigate the subsurface in all directions and analyses different sections and slices or moreover navigate the iso-surfaces respect to a value (or interval). The last one allows to isolate one or more iso-surfaces and remove, in the visualization mode, other data not interesting for the analysis; finally it helps to individuate the underground 3D bodies. Other aspect is the needs to link the on-ground data, as imaging, to the underground one by geographical and context field of view.

  6. Numerical investigation of smart base isolation system employing MR elastomer

    Energy Technology Data Exchange (ETDEWEB)

    Usman, M; Sung, S H; Jang, D D; Jung, H J [Department of Civil and Environmental Engineering, KAIST, 305-701, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Koo, J H [Department of Mechanical and Manufacturing Engineering, Miami University, Oxford, Ohio 45056 (United States)], E-mail: hjung@kaist.ac.kr

    2009-02-01

    This paper evaluates the dynamic performance of a newly proposed smart base isolation system employing Magneto-Rheological Elastomers (MREs). MREs belong to a class of smart materials whose elastic modulus or stiffness can be adjusted by varying the magnitude of the magnetic field. The base isolation systems are considered as one of the most effective devices for vibration reduction of civil engineering structures in the event of earthquakes. The proposed base isolation system strives to enhance the performance of the conventional base-isolation system by using controllable MREs. To validate the effectiveness of the MRE-based isolation system, an extensive simulation study has been performed using a five degree-of-freedom structure under several historical earthquake excitations. The results show that the proposed system outperformed the conventional system in reducing the responses of the structure in all the seismic excitations considered in the study.

  7. Numerical investigation of smart base isolation system employing MR elastomer

    Science.gov (United States)

    Usman, M.; Sung, S. H.; Jang, D. D.; Jung, H. J.; Koo, J. H.

    2009-02-01

    This paper evaluates the dynamic performance of a newly proposed smart base isolation system employing Magneto-Rheological Elastomers (MREs). MREs belong to a class of smart materials whose elastic modulus or stiffness can be adjusted by varying the magnitude of the magnetic field. The base isolation systems are considered as one of the most effective devices for vibration reduction of civil engineering structures in the event of earthquakes. The proposed base isolation system strives to enhance the performance of the conventional base-isolation system by using controllable MREs. To validate the effectiveness of the MRE-based isolation system, an extensive simulation study has been performed using a five degree-of-freedom structure under several historical earthquake excitations. The results show that the proposed system outperformed the conventional system in reducing the responses of the structure in all the seismic excitations considered in the study.

  8. Investigation of Brain Arterial Circle Malformations Using Electrical Modelling and Simulation

    Directory of Open Access Journals (Sweden)

    Klara Capova

    2006-01-01

    Full Text Available The paper deals with the cerebral arterial system investigation by means of electrical modelling and simulations. The main attention is paid to the brain arterial circle malformations (stenoses and aneurysms and their determination and evaluation by computer-aided methods as tools of a non-invasive diagnostics. The compensation possibilities of brain arterial circle in case of presence of concrete arterial malformations are modelled and simulated. The simulation results of brain arteries blood pressures and volume flow velocities time dependences are presented and discussed under various health conditions.

  9. Similarity solutions for systems arising from an Aedes aegypti model

    Science.gov (United States)

    Freire, Igor Leite; Torrisi, Mariano

    2014-04-01

    In a recent paper a new model for the Aedes aegypti mosquito dispersal dynamics was proposed and its Lie point symmetries were investigated. According to the carried group classification, the maximal symmetry Lie algebra of the nonlinear cases is reached whenever the advection term vanishes. In this work we analyze the family of systems obtained when the wind effects on the proposed model are neglected. Wide new classes of solutions to the systems under consideration are obtained.

  10. Learning Markov models for stationary system behaviors

    DEFF Research Database (Denmark)

    Chen, Yingke; Mao, Hua; Jaeger, Manfred

    2012-01-01

    Establishing an accurate model for formal verification of an existing hardware or software system is often a manual process that is both time consuming and resource demanding. In order to ease the model construction phase, methods have recently been proposed for automatically learning accurate...... system models from data in the form of observations of the target system. Common for these approaches is that they assume the data to consist of multiple independent observation sequences. However, for certain types of systems, in particular many running embedded systems, one would only have access...... the learned model. Experiments demonstrate that system properties (formulated as stationary probabilities of LTL formulas) can be reliably identified using the learned model....

  11. Integrating systems biology models and biomedical ontologies

    Directory of Open Access Journals (Sweden)

    de Bono Bernard

    2011-08-01

    Full Text Available Abstract Background Systems biology is an approach to biology that emphasizes the structure and dynamic behavior of biological systems and the interactions that occur within them. To succeed, systems biology crucially depends on the accessibility and integration of data across domains and levels of granularity. Biomedical ontologies were developed to facilitate such an integration of data and are often used to annotate biosimulation models in systems biology. Results We provide a framework to integrate representations of in silico systems biology with those of in vivo biology as described by biomedical ontologies and demonstrate this framework using the Systems Biology Markup Language. We developed the SBML Harvester software that automatically converts annotated SBML models into OWL and we apply our software to those biosimulation models that are contained in the BioModels Database. We utilize the resulting knowledge base for complex biological queries that can bridge levels of granularity, verify models based on the biological phenomenon they represent and provide a means to establish a basic qualitative layer on which to express the semantics of biosimulation models. Conclusions We establish an information flow between biomedical ontologies and biosimulation models and we demonstrate that the integration of annotated biosimulation models and biomedical ontologies enables the verification of models as well as expressive queries. Establishing a bi-directional information flow between systems biology and biomedical ontologies has the potential to enable large-scale analyses of biological systems that span levels of granularity from molecules to organisms.

  12. Integrating systems biology models and biomedical ontologies

    Science.gov (United States)

    2011-01-01

    Background Systems biology is an approach to biology that emphasizes the structure and dynamic behavior of biological systems and the interactions that occur within them. To succeed, systems biology crucially depends on the accessibility and integration of data across domains and levels of granularity. Biomedical ontologies were developed to facilitate such an integration of data and are often used to annotate biosimulation models in systems biology. Results We provide a framework to integrate representations of in silico systems biology with those of in vivo biology as described by biomedical ontologies and demonstrate this framework using the Systems Biology Markup Language. We developed the SBML Harvester software that automatically converts annotated SBML models into OWL and we apply our software to those biosimulation models that are contained in the BioModels Database. We utilize the resulting knowledge base for complex biological queries that can bridge levels of granularity, verify models based on the biological phenomenon they represent and provide a means to establish a basic qualitative layer on which to express the semantics of biosimulation models. Conclusions We establish an information flow between biomedical ontologies and biosimulation models and we demonstrate that the integration of annotated biosimulation models and biomedical ontologies enables the verification of models as well as expressive queries. Establishing a bi-directional information flow between systems biology and biomedical ontologies has the potential to enable large-scale analyses of biological systems that span levels of granularity from molecules to organisms. PMID:21835028

  13. Very Large System Dynamics Models - Lessons Learned

    Energy Technology Data Exchange (ETDEWEB)

    Jacob J. Jacobson; Leonard Malczynski

    2008-10-01

    This paper provides lessons learned from developing several large system dynamics (SD) models. System dynamics modeling practice emphasize the need to keep models small so that they are manageable and understandable. This practice is generally reasonable and prudent; however, there are times that large SD models are necessary. This paper outlines two large SD projects that were done at two Department of Energy National Laboratories, the Idaho National Laboratory and Sandia National Laboratories. This paper summarizes the models and then discusses some of the valuable lessons learned during these two modeling efforts.

  14. Precipitation-runoff modeling system; user's manual

    Science.gov (United States)

    Leavesley, G.H.; Lichty, R.W.; Troutman, B.M.; Saindon, L.G.

    1983-01-01

    The concepts, structure, theoretical development, and data requirements of the precipitation-runoff modeling system (PRMS) are described. The precipitation-runoff modeling system is a modular-design, deterministic, distributed-parameter modeling system developed to evaluate the impacts of various combinations of precipitation, climate, and land use on streamflow, sediment yields, and general basin hydrology. Basin response to normal and extreme rainfall and snowmelt can be simulated to evaluate changes in water balance relationships, flow regimes, flood peaks and volumes, soil-water relationships, sediment yields, and groundwater recharge. Parameter-optimization and sensitivity analysis capabilites are provided to fit selected model parameters and evaluate their individual and joint effects on model output. The modular design provides a flexible framework for continued model system enhancement and hydrologic modeling research and development. (Author 's abstract)

  15. Network model of security system

    Directory of Open Access Journals (Sweden)

    Adamczyk Piotr

    2016-01-01

    Full Text Available The article presents the concept of building a network security model and its application in the process of risk analysis. It indicates the possibility of a new definition of the role of the network models in the safety analysis. Special attention was paid to the development of the use of an algorithm describing the process of identifying the assets, vulnerability and threats in a given context. The aim of the article is to present how this algorithm reduced the complexity of the problem by eliminating from the base model these components that have no links with others component and as a result and it was possible to build a real network model corresponding to reality.

  16. Evaluation Model of System Survivability

    Institute of Scientific and Technical Information of China (English)

    LIU Yuling; PAN Shiying; TIAN Junfeng

    2006-01-01

    This paper puts forward a survivability evaluation model, SQEM(Survivability Quantitative Evaluation Model), based on lucubrating the main method existed. Then it defines the measurement factors and parses the survivability mathematically, introduces state change probability and the idea of setting the weights of survivability factors dynamically into the evaluating process of SQEM, which improved the accuracy of evaluation. An example is presented to illustrate the way SQEM works, which demonstrated the validity and feasibility of the method.

  17. Brief history of agricultural systems modeling.

    Science.gov (United States)

    Jones, James W; Antle, John M; Basso, Bruno; Boote, Kenneth J; Conant, Richard T; Foster, Ian; Godfray, H Charles J; Herrero, Mario; Howitt, Richard E; Janssen, Sander; Keating, Brian A; Munoz-Carpena, Rafael; Porter, Cheryl H; Rosenzweig, Cynthia; Wheeler, Tim R

    2017-07-01

    Agricultural systems science generates knowledge that allows researchers to consider complex problems or take informed agricultural decisions. The rich history of this science exemplifies the diversity of systems and scales over which they operate and have been studied. Modeling, an essential tool in agricultural systems science, has been accomplished by scientists from a wide range of disciplines, who have contributed concepts and tools over more than six decades. As agricultural scientists now consider the "next generation" models, data, and knowledge products needed to meet the increasingly complex systems problems faced by society, it is important to take stock of this history and its lessons to ensure that we avoid re-invention and strive to consider all dimensions of associated challenges. To this end, we summarize here the history of agricultural systems modeling and identify lessons learned that can help guide the design and development of next generation of agricultural system tools and methods. A number of past events combined with overall technological progress in other fields have strongly contributed to the evolution of agricultural system modeling, including development of process-based bio-physical models of crops and livestock, statistical models based on historical observations, and economic optimization and simulation models at household and regional to global scales. Characteristics of agricultural systems models have varied widely depending on the systems involved, their scales, and the wide range of purposes that motivated their development and use by researchers in different disciplines. Recent trends in broader collaboration across institutions, across disciplines, and between the public and private sectors suggest that the stage is set for the major advances in agricultural systems science that are needed for the next generation of models, databases, knowledge products and decision support systems. The lessons from history should be

  18. Information modeling system for blast furnace control

    Science.gov (United States)

    Spirin, N. A.; Gileva, L. Y.; Lavrov, V. V.

    2016-09-01

    Modern Iron & Steel Works as a rule are equipped with powerful distributed control systems (DCS) and databases. Implementation of DSC system solves the problem of storage, control, protection, entry, editing and retrieving of information as well as generation of required reporting data. The most advanced and promising approach is to use decision support information technologies based on a complex of mathematical models. The model decision support system for control of blast furnace smelting is designed and operated. The basis of the model system is a complex of mathematical models created using the principle of natural mathematical modeling. This principle provides for construction of mathematical models of two levels. The first level model is a basic state model which makes it possible to assess the vector of system parameters using field data and blast furnace operation results. It is also used to calculate the adjustment (adaptation) coefficients of the predictive block of the system. The second-level model is a predictive model designed to assess the design parameters of the blast furnace process when there are changes in melting conditions relative to its current state. Tasks for which software is developed are described. Characteristics of the main subsystems of the blast furnace process as an object of modeling and control - thermal state of the furnace, blast, gas dynamic and slag conditions of blast furnace smelting - are presented.

  19. Investigation of the photovoltaic cell/ thermoelectric element hybrid system performance

    Science.gov (United States)

    Cotfas, D. T.; Cotfas, P. A.; Machidon, O. M.; Ciobanu, D.

    2016-06-01

    The PV/TEG hybrid system, consisting of the photovoltaic cells and thermoelectric element, is presented in the paper. The dependence of the PV/TEG hybrid system parameters on the illumination levels and the temperature is analysed. The maxim power values of the photovoltaic cell, of the thermoelectric element and of the PV/TEG system are calculated and a comparison between them is presented and analysed. An economic analysis is also presented.

  20. Developing a Model of the Irish Energy-System

    DEFF Research Database (Denmark)

    Connolly, David; Lund, Henrik; Mathiesen, Brian Vad

    2009-01-01

    to be created. This paper focuses on the construction of this reference model, in terms of the data gathered, the assumptions made and the accuracy achieved. In future work, this model will be used to investigate alternative energy-systems for Ireland, with the aim to determine the most effective energy system......The transition from a fossil-fuel to a renewable energy system is a modern and complicated challenge for numerous countries. However, as Ireland is an island that is poorly interconnected to other energy systems, this challenge becomes even more complicated. Identifying how to make this transition...... is a vital step due to the scale of the change required for large-scale renewable penetrations. In this paper, a model of the Irish energy system is created to identify how Ireland can transform from a fossil-fuel to a renewable energy-system. The energy-systems-analysis tool, EnergyPLAN, was chosen...