WorldWideScience

Sample records for nonrotating modal analysis

  1. Modal Analysis in Periodic, Time-Varying Systems with emphasis to the Coupling between Flexible Rotating Beams and Non-Rotating Flexible Structures

    DEFF Research Database (Denmark)

    Saracho, C. M.; Santos, Ilmar

    2003-01-01

    The analysis of dynamical response of a system built by a non-rotating structure coupled to flexible rotating beams is the purpose of this work. The effect of rotational speed upon the beam natural frequencies is well-known, so that an increase in the angular speeds leads to an increase in beam...... natural frequencies, the so-called centrifugal stiffening. The equations of motion of such a global system present matrices with time-depending coefficients, which vary periodically with the angular rotor speed, and introduce parametric vibrations into the system response. The principles of modal analysis...... for time-invariant linear systems are expanded to investigate time-varying systems. Concepts as eigenvalues and eigenvectors, which in this special case are also time-varying, are used to analyse the dynamical response of global system. The time-varying frequencies and modes are also illustrated....

  2. Experimental modal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ibsen, Lars Bo; Liingaard, M.

    2006-12-15

    This technical report concerns the basic theory and principles for experimental modal analysis. The sections within the report are: Output-only modal analysis software, general digital analysis, basics of structural dynamics and modal analysis and system identification. (au)

  3. Operational Modal Analysis Tutorial

    DEFF Research Database (Denmark)

    Brincker, Rune; Andersen, Palle

    of modal parameters of practical interest - including the mode shape scaling factor - with a high degree of accuracy. It is also argued that the operational technology offers the user a number of advantages over traditional modal testing. The operational modal technology allows the user to perform a modal......In this paper the basic principles in operational modal testing and analysis are presented and discussed. A brief review of the techniques for operational modal testing and identification is presented, and it is argued, that there is now a wide range of techniques for effective identification...

  4. Noise elimination algorithm for modal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bao, X. X., E-mail: baoxingxian@upc.edu.cn [Department of Naval Architecture and Ocean Engineering, China University of Petroleum (East China), Qingdao 266580 (China); Li, C. L. [Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China); Xiong, C. B. [The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061 (China)

    2015-07-27

    Modal analysis is an ongoing interdisciplinary physical issue. Modal parameters estimation is applied to determine the dynamic characteristics of structures under vibration excitation. Modal analysis is more challenging for the measured vibration response signals are contaminated with noise. This study develops a mathematical algorithm of structured low rank approximation combined with the complex exponential method to estimate the modal parameters. Physical experiments using a steel cantilever beam with ten accelerometers mounted, excited by an impulse load, demonstrate that this method can significantly eliminate noise from measured signals and accurately identify the modal frequencies and damping ratios. This study provides a fundamental mechanism of noise elimination using structured low rank approximation in physical fields.

  5. Load Estimation from Natural input Modal Analysis

    DEFF Research Database (Denmark)

    Aenlle, Manuel López; Brincker, Rune; Canteli, Alfonso Fernández

    2005-01-01

    One application of Natural Input Modal Analysis consists in estimating the unknown load acting on structures such as wind loads, wave loads, traffic loads, etc. In this paper, a procedure to determine loading from a truncated modal model, as well as the results of an experimental testing programme...... estimation. In the experimental program a small structure subjected to vibration was used to estimate the loading from the measurements and the experimental modal space. The modal parameters were estimated by Natural Input Modal Analysis and the scaling factors of the mode shapes obtained by the mass change...

  6. History of Civil Engineering Modal Analysis

    DEFF Research Database (Denmark)

    Brincker, Rune

    2008-01-01

    techniques are available for civil engineering modal analysis. The testing of civil structures defers from the traditional modal testing in the sense, that very often it is difficult, or sometimes impossible, to artificially excite a large civil engineering structure. Also, many times, even though...

  7. Complex harmonic modal analysis of rotor systems

    International Nuclear Information System (INIS)

    Han, Dong Ju

    2015-01-01

    Complex harmonic analysis for rotor systems has been proposed from the strict complex modal analysis based upon Floquet theory. In this process the harmonic balance method is adopted, effectively associated with conventional eigenvalue analysis. Also, the harmonic coefficients equivalent to dFRFs in harmonic mode has been derived in practice. The modes are classified from identifying the modal characteristics, and the adaptation of harmonic balance method has been proven by comparing the results of the stability analyses from Floque theory and the eigen analysis. The modal features of each critical speed are depicted in quantitatively and qualitatively by showing that the strengths of each component of the harmonic coefficients are estimated from the order of magnitude analysis according to their harmonic patterns. This effectiveness has been verified by comparing with the numerical solutions

  8. Applied modal analysis of wind turbine blades

    DEFF Research Database (Denmark)

    Pedersen, H.B.; Kristensen, O.J.D.

    2003-01-01

    In this project modal analysis has been used to determine the natural frequencies, damping and the mode shapes for wind turbine blades. Different methods to measure the position and adjust the direction of the measuring points are discussed. Differentequipment for mounting the accelerometers...... is investigated by repeated measurement on the same wind turbine blade. Furthermore the flexibility of the test set-up is investigated, by use ofaccelerometers mounted on the flexible adapter plate during the measurement campaign. One experimental campaign investigated the results obtained from a loaded...... and unloaded wind turbine blade. During this campaign the modal analysis are performed on ablade mounted in a horizontal and a vertical position respectively. Finally the results obtained from modal analysis carried out on a wind turbine blade are compared with results obtained from the Stig Øyes blade_EV1...

  9. Operational Modal Analysis of the Cablestayed Footbridge

    Directory of Open Access Journals (Sweden)

    Kortiš Ján

    2017-12-01

    Full Text Available Modern architecture leads to design subtle bridge structures that are more sensitive to increased dynamic loading than the massive ones. This phenomenon can be especially observed on lightweight steel structures such as suspended footbridges. As a result, it is necessary to know precisely its dynamic characteristics, such as natural frequencies, natural shapes and damping of construction. This information can be used for further analysis such as damage detection, system identification, health monitoring, etc. or also for the design of new types of construction. For this purpose, classical modal analysis using trigger load or harmonic vibration exciter in combination with acceleration sensors is used in practice. However, there are many situations where it is not possible to stop the traffic or operation of the bridge. The article presents an experimental measurement of the dynamic parameters of the structure at the operating load using the operational modal analysis.

  10. Operational Modal Analysis of the Cablestayed Footbridge

    Science.gov (United States)

    Kortiš, Ján; Daniel, Ľuboš; Farbák, Matúš; Maliar, Lukáš; Škarupa, Milan

    2017-12-01

    Modern architecture leads to design subtle bridge structures that are more sensitive to increased dynamic loading than the massive ones. This phenomenon can be especially observed on lightweight steel structures such as suspended footbridges. As a result, it is necessary to know precisely its dynamic characteristics, such as natural frequencies, natural shapes and damping of construction. This information can be used for further analysis such as damage detection, system identification, health monitoring, etc. or also for the design of new types of construction. For this purpose, classical modal analysis using trigger load or harmonic vibration exciter in combination with acceleration sensors is used in practice. However, there are many situations where it is not possible to stop the traffic or operation of the bridge. The article presents an experimental measurement of the dynamic parameters of the structure at the operating load using the operational modal analysis.

  11. Non-modal analysis in plasmas

    International Nuclear Information System (INIS)

    Mahajan, S.M.; Rogava, A.D.; Berezhiani, V.

    1996-01-01

    The techniques of non-modal analysis are applied to investigate the time evolution of a variety of plasma flows with velocity shear. It is shown that large transient amplifications may result for appropriate initial perturbations. The role of this amplification in determining the nonlinear dynamics of these systems (when all the normal modes are stable) is discussed. Examples are taken from Laboratory, astrophysical and cosmic plasmas

  12. Applied modal analysis of wind turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Broen Pedersen, H.; Dahl Kristensen, O.J.

    2003-02-01

    In this project modal analysis has been used to determine the natural frequencies, damping and the mode shapes for wind turbine blades. Different methods to measure the position and adjust the direction of the measuring points are discussed. Different equipment for mounting the accelerometers are investigated and the most suitable are chosen. Different excitation techniques are tried during experimental campaigns. After a discussion the pendulum hammer were chosen, and a new improved hammer was manufactured. Some measurement errors are investigated. The ability to repeat the measured results is investigated by repeated measurement on the same wind turbine blade. Furthermore the flexibility of the test set-up is investigated, by use of accelerometers mounted on the flexible adapter plate during the measurement campaign. One experimental campaign investigated the results obtained from a loaded and unloaded wind turbine blade. During this campaign the modal analysis are performed on a blade mounted in a horizontal and a vertical position respectively. Finally the results obtained from modal analysis carried out on a wind turbine blade are compared with results obtained from the Stig Oeyes blade{sub E}V1 program. (au)

  13. Modality

    DEFF Research Database (Denmark)

    Klinge, Alex; Müller, Henrik Høeg

    Modality: Studies in Form and Function reflects the diversity of theoretical frameworks and the heterogeneity of linguistic phenomena under the general heading of modality. Researchers in the fields of logic, philosophy and linguistics have for many years been pondering the elusive nature...... of modality and grappled with ways of capturing it. The 11 studies included here cover the span from contributions that seek to clarify controversial theoretical constructs to studies which take an empirical approach to linguistic categories and cross-linguistic typological issues. The key concepts addressed...

  14. Modal analysis of wind turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, G.C.; Hansen, M.H.; Baumgart, A.; Carlen, I.

    2002-02-01

    The modal analysis technique has been used to identify essential dynamic properties of wind turbine blades like natural frequencies, damping characteristics and mode shapes. Different experimental procedures have been considered, and the most appropriate of these has been selected. Although the comparison is based on measurements on a LM 19 m blade, the recommendations given are believed to be valid for other wind turbine blades as well. The reliability of the selected experimental analysis has been quantified by estimating the unsystematic variations in the experimental findings. Satisfactory results have been obtained for natural frequencies, damping characteristics and for the dominating deflection direction of the investigated mode shapes. For the secondary deflection directions, the observed experimental uncertainty may be considerable - especially for the torsional deflection. The experimental analysis of the LM 19 m blade has been compared with results from a state-of-the-art FE-modeling of the same blade. For some of the higher modes substantial discrepancies between the natural frequencies originating from the FE-modeling and the modal analysis, respectively, are observed. In general the qualitative features of measured and computed modes shapes are in good agreement. However, for the secondary deflection directions, substantial deviations in the absolute values may occur (when normalizing with respect to the primary deflection direction). Finally, suggestions of potential future improvements of the experimental procedure are discussed. (au)

  15. Approximate modal analysis using Fourier decomposition

    International Nuclear Information System (INIS)

    Kozar, Ivica; Jericevic, Zeljko; Pecak, Tatjana

    2010-01-01

    The paper presents a novel numerical approach for approximate solution of eigenvalue problem and investigates its suitability for modal analysis of structures with special attention on plate structures. The approach is based on Fourier transformation of the matrix equation into frequency domain and subsequent removal of potentially less significant frequencies. The procedure results in a much reduced problem that is used in eigenvalue calculation. After calculation eigenvectors are expanded and transformed back into time domain. The principles are presented in Jericevic [1]. Fourier transform can be formulated in a way that some parts of the matrix that should not be approximated are not transformed but are fully preserved. In this paper we present formulation that preserves central or edge parts of the matrix and compare it with the formulation that performs transform on the whole matrix. Numerical experiments on transformed structural dynamic matrices describe quality of the approximations obtained in modal analysis of structures. On the basis of the numerical experiments, from the three approaches to matrix reduction one is recommended.

  16. Operational Modal Analysis of Rotating Machinery

    DEFF Research Database (Denmark)

    Gres, Szymon; Andersen, Palle; Damkilde, Lars

    2019-01-01

    and deploys an orthogonal projection of the latter onto the raw measurements to remove the harmonic part of the signal. The new technique is a part of an semi-automated framework for OMA of structures contaminated with harmonics, whose flow is presented in this paper. The merit of the framework is discussed......Harmonic excitation of structures caused by rotating equipment is a problem faced by many engineers in the field of Operational Modal Analysis (OMA). Several methods to discard the influence of harmonic inputs over systems natural responses has been proposed in the literature and implemented...... in various software solutions. This paper recalls some of the most used techniques and uses a new time domain method for removing harmonics from measurements. Deployed method does not rely on filtering, statistical detection nor on non-linear fitting. Instead, it predicts the harmonic part of the time series...

  17. The contribution to the modal analysis using an infrared camera

    Directory of Open Access Journals (Sweden)

    Dekys Vladimír

    2018-01-01

    Full Text Available The paper deals with modal analysis using an infrared camera. The test objects were excited by the modal exciter with narrowband noise and the response was registered as a frame sequence by the high speed infrared camera FLIR SC7500. The resonant frequencies and the modal shapes were determined from the infrared spectrum recordings. Lock-in technology has also been used. The experimental results were compared with calculated natural frequencies and modal shapes.

  18. Limitations of modal analysis of damped structures

    International Nuclear Information System (INIS)

    Krapf, K.G.; Woelfel, H.

    1983-01-01

    Quite recently discrete spring-damper elements are increasingly used for the low-tuned supports of nuclear power-plant buildings and equipment (reactor building, turbine-fundaments etc.) to reduce the vibration response due to the dynamic load cases earthquake and airplane crash. Because of this development, it is to be investigated whether the usual modal analysis method is applicable within the design process or should be changed respectively replaced in special cases. The paper contributes to this discussion by demonstrating and valuing the discrepancies in the different ways for the implementation of damping. Different methods for uncoupling (energy weighting, reduction to Rayleigh-damping) are compared with the solution of the coupled equations of motion. In particular vertical vibrations of a spring-damper-supported building on foundation (including ground springs) are examined using a two-degree-of-freedom-system. The results of coupled and (by force) uncoupled methods are interpreted concerning free vibration by comparison of the damping of natural vibrations, natural frequencies and natural mode shapes. The effect on the forced vibrations is shown by floor response spectra to an earthquake accelerogram. (orig./HP)

  19. Supervised Cross-Modal Factor Analysis for Multiple Modal Data Classification

    KAUST Repository

    Wang, Jingbin

    2015-10-09

    In this paper we study the problem of learning from multiple modal data for purpose of document classification. In this problem, each document is composed two different modals of data, i.e., An image and a text. Cross-modal factor analysis (CFA) has been proposed to project the two different modals of data to a shared data space, so that the classification of a image or a text can be performed directly in this space. A disadvantage of CFA is that it has ignored the supervision information. In this paper, we improve CFA by incorporating the supervision information to represent and classify both image and text modals of documents. We project both image and text data to a shared data space by factor analysis, and then train a class label predictor in the shared space to use the class label information. The factor analysis parameter and the predictor parameter are learned jointly by solving one single objective function. With this objective function, we minimize the distance between the projections of image and text of the same document, and the classification error of the projection measured by hinge loss function. The objective function is optimized by an alternate optimization strategy in an iterative algorithm. Experiments in two different multiple modal document data sets show the advantage of the proposed algorithm over other CFA methods.

  20. Dynamic analysis of pipings by Modal Synthesis

    International Nuclear Information System (INIS)

    Augusto, O.B.; Mattar Neto, M.

    1986-01-01

    A Modal Synthesis method, the component modes, and its implementation as a post-processor of finite element program is presented. Examples of calculations of stationary and transient vibrations for monitoring pipelines of nuclear power plants are analysed. (M.C.K.) [pt

  1. Quantitative multi-modal NDT data analysis

    International Nuclear Information System (INIS)

    Heideklang, René; Shokouhi, Parisa

    2014-01-01

    A single NDT technique is often not adequate to provide assessments about the integrity of test objects with the required coverage or accuracy. In such situations, it is often resorted to multi-modal testing, where complementary and overlapping information from different NDT techniques are combined for a more comprehensive evaluation. Multi-modal material and defect characterization is an interesting task which involves several diverse fields of research, including signal and image processing, statistics and data mining. The fusion of different modalities may improve quantitative nondestructive evaluation by effectively exploiting the augmented set of multi-sensor information about the material. It is the redundant information in particular, whose quantification is expected to lead to increased reliability and robustness of the inspection results. There are different systematic approaches to data fusion, each with its specific advantages and drawbacks. In our contribution, these will be discussed in the context of nondestructive materials testing. A practical study adopting a high-level scheme for the fusion of Eddy Current, GMR and Thermography measurements on a reference metallic specimen with built-in grooves will be presented. Results show that fusion is able to outperform the best single sensor regarding detection specificity, while retaining the same level of sensitivity

  2. Supervised Cross-Modal Factor Analysis for Multiple Modal Data Classification

    KAUST Repository

    Wang, Jingbin; Zhou, Yihua; Duan, Kanghong; Wang, Jim Jing-Yan; Bensmail, Halima

    2015-01-01

    . In this paper, we improve CFA by incorporating the supervision information to represent and classify both image and text modals of documents. We project both image and text data to a shared data space by factor analysis, and then train a class label predictor

  3. An operational modal analysis method in frequency and spatial domain

    Science.gov (United States)

    Wang, Tong; Zhang, Lingmi; Tamura, Yukio

    2005-12-01

    A frequency and spatial domain decomposition method (FSDD) for operational modal analysis (OMA) is presented in this paper, which is an extension of the complex mode indicator function (CMIF) method for experimental modal analysis (EMA). The theoretical background of the FSDD method is clarified. Singular value decomposition is adopted to separate the signal space from the noise space. Finally, an enhanced power spectrum density (PSD) is proposed to obtain more accurate modal parameters by curve fitting in the frequency domain. Moreover, a simulation case and an application case are used to validate this method.

  4. Dynamic behaviour studies of a vertical axis wind turbine blade using Operational Modal Analysis (OMA) and Experimental Modal Analysis (EMA)

    DEFF Research Database (Denmark)

    Najafi, Nadia; Schmidt Paulsen, Uwe; Belloni, F.

    2014-01-01

    Dynamic behavior of a modified blade fitted onto a small 1 kW vertical-axis wind turbine is studied by two different approaches: Classical modal analysis (EMA) is carried out to validate the results of Operational Modal Analysis (OMA). In traditional modal analysis (EMA) one axis accelerometers...... it is excited by random and wind forces. The cameras are programmed in LabView to take pictures at the same time with 180 fps and store them on a high speed hard disk. The output deflection will be investigated in frequency domain by peak picking method, and then AR (Autoregressive) model is applied to describe...

  5. Dynamic Modal Analysis of Vertical Machining Centre Components

    OpenAIRE

    Anayet U. Patwari; Waleed F. Faris; A. K. M. Nurul Amin; S. K. Loh

    2009-01-01

    The paper presents a systematic procedure and details of the use of experimental and analytical modal analysis technique for structural dynamic evaluation processes of a vertical machining centre. The main results deal with assessment of the mode shape of the different components of the vertical machining centre. The simplified experimental modal analysis of different components of milling machine was carried out. This model of the different machine tool's structure is made by design software...

  6. Modal interval analysis new tools for numerical information

    CERN Document Server

    Sainz, Miguel A; Calm, Remei; Herrero, Pau; Jorba, Lambert; Vehi, Josep

    2014-01-01

    This book presents an innovative new approach to interval analysis. Modal Interval Analysis (MIA) is an attempt to go beyond the limitations of classic intervals in terms of their structural, algebraic and logical features. The starting point of MIA is quite simple: It consists in defining a modal interval that attaches a quantifier to a classical interval and in introducing the basic relation of inclusion between modal intervals by means of the inclusion of the sets of predicates they accept. This modal approach introduces interval extensions of the real continuous functions, identifies equivalences between logical formulas and interval inclusions, and provides the semantic theorems that justify these equivalences, along with guidelines for arriving at these inclusions. Applications of these equivalences in different areas illustrate the obtained results. The book also presents a new interval object: marks, which aspire to be a new form of numerical treatment of errors in measurements and computations.

  7. Ambient Response Analysis Modal Analysis for Large Structures

    DEFF Research Database (Denmark)

    Brincker, Rune; Andersen, Palle

    1999-01-01

    In this paper an outline is given of the basic ideas in ambient respons analysis, i.e. when modal analyses is performed on systems based on output only. Some of the most known techniques are briefly introduced, and the basic problems discussed. The introduced techniques are the frequency domain...... based peak-picking methods, the polyreference LSCE method, the stochastic subspace method for estimation of state space systems and the prediction error method for estimation of Auto-Regressive Moving Average Vector models. The techniques are illustrated on an example of ambient response measurments...

  8. Analysis of modal frequency optimization of railway vehicle car body

    Directory of Open Access Journals (Sweden)

    Wenjing Sun

    2016-04-01

    Full Text Available High structural modal frequencies of car body are beneficial as they ensure better vibration control and enhance ride quality of railway vehicles. Modal sensitivity optimization and elastic suspension parameters used in the design of equipment beneath the chassis of the car body are proposed in order to improve the modal frequencies of car bodies under service conditions. Modal sensitivity optimization is based on sensitivity analysis theory which considers the thickness of the body frame at various positions as variables in order to achieve optimization. Equipment suspension design analyzes the influence of suspension parameters on the modal frequencies of the car body through the use of an equipment-car body coupled model. Results indicate that both methods can effectively improve the modal parameters of the car body. Modal sensitivity optimization increases vertical bending frequency from 9.70 to 10.60 Hz, while optimization of elastic suspension parameters increases the vertical bending frequency to 10.51 Hz. The suspension design can be used without alteration to the structure of the car body while ensuring better ride quality.

  9. Spatial Analysis of Case-Mix and Dialysis Modality Associations.

    Science.gov (United States)

    Phirtskhalaishvili, Tamar; Bayer, Florian; Edet, Stephane; Bongiovanni, Isabelle; Hogan, Julien; Couchoud, Cécile

    2016-01-01

    ♦ Health-care systems must attempt to provide appropriate, high-quality, and economically sustainable care that meets the needs and choices of patients with end-stage renal disease (ESRD). France offers 9 different modalities of dialysis, each characterized by dialysis technique, the extent of professional assistance, and the treatment site. The aim of this study was 1) to describe the various dialysis modalities in France and the patient characteristics associated with each of them, and 2) to analyze their regional patterns to identify possible unexpected associations between case-mixes and dialysis modalities. ♦ The clinical characteristics of the 37,421 adult patients treated by dialysis were described according to their treatment modality. Agglomerative hierarchical cluster analysis was used to aggregate the regions into clusters according to their use of these modalities and the characteristics of their patients. ♦ The gradient of patient characteristics was similar from home hemodialyis (HD) to in-center HD and from non-assisted automated peritoneal dialysis (APD) to assisted continuous ambulatory peritoneal dialysis (CAPD). Analyzing their spatial distribution, we found differences in the patient case-mix on dialysis across regions but also differences in the health-care provided for them. The classification of the regions into 6 different clusters allowed us to detect some unexpected associations between case-mixes and treatment modalities. ♦ The 9 modalities of treatment available make it theoretically possible to adapt treatment to patients' clinical characteristics and abilities. However, although we found an overall appropriate association of dialysis modalities to the case-mix, major inter-region heterogeneity and the low rate of peritoneal dialysis (PD) and home HD suggest that factors besides patients' clinical conditions impact the choice of dialysis modality. The French organization should now be evaluated in terms of patients' quality of

  10. Direct calculation of modal contributions to thermal conductivity via Green–Kubo modal analysis

    International Nuclear Information System (INIS)

    Lv, Wei; Henry, Asegun

    2016-01-01

    We derived a new method for direct calculation of the modal contributions to thermal conductivity, which is termed Green–Kubo modal analysis (GKMA). The GKMA method combines the lattice dynamics formalism with the Green–Kubo formula for thermal conductivity, such that the thermal conductivity becomes a direct summation of modal contributions, where one need not define the phonon velocity. As a result, the GKMA method can be applied to any material/group of atoms, where the atoms vibrate around stable equilibrium positions, which includes non-stoichiometric compounds, random alloys, amorphous materials and even rigid molecules. By using molecular dynamics simulations to obtain the time history of each mode’s contribution to the heat current, one naturally includes anharmonicity to full order and can obtain insight into the interactions between different modes through the cross-correlations. As an example, we applied the GMKA method to crystalline and amorphous silicon. The modal contributions at each frequency result from the analysis and thereby allow one to apply a quantum correction to the mode heat capacity to determine the temperature dependence of thermal conductivity. The predicted temperature dependent thermal conductivity for amorphous silicon shows the best agreement with experiments to date. The GKMA method provides new insight into the nature of phonon transport, as it casts the problem in terms of mode–mode correlation instead of scattering, and provides a general unified formalism that can be used to understand phonon–phonon interactions in essentially any class of materials or structures where the atoms vibrate around stable equilibrium sites. (paper)

  11. Dual ant colony operational modal analysis parameter estimation method

    Science.gov (United States)

    Sitarz, Piotr; Powałka, Bartosz

    2018-01-01

    Operational Modal Analysis (OMA) is a common technique used to examine the dynamic properties of a system. Contrary to experimental modal analysis, the input signal is generated in object ambient environment. Operational modal analysis mainly aims at determining the number of pole pairs and at estimating modal parameters. Many methods are used for parameter identification. Some methods operate in time while others in frequency domain. The former use correlation functions, the latter - spectral density functions. However, while some methods require the user to select poles from a stabilisation diagram, others try to automate the selection process. Dual ant colony operational modal analysis parameter estimation method (DAC-OMA) presents a new approach to the problem, avoiding issues involved in the stabilisation diagram. The presented algorithm is fully automated. It uses deterministic methods to define the interval of estimated parameters, thus reducing the problem to optimisation task which is conducted with dedicated software based on ant colony optimisation algorithm. The combination of deterministic methods restricting parameter intervals and artificial intelligence yields very good results, also for closely spaced modes and significantly varied mode shapes within one measurement point.

  12. Comparative Modal Analysis of Sieve Hardware Designs

    Science.gov (United States)

    Thompson, Nathaniel

    2012-01-01

    The CMTB Thwacker hardware operates as a testbed analogue for the Flight Thwacker and Sieve components of CHIMRA, a device on the Curiosity Rover. The sieve separates particles with a diameter smaller than 150 microns for delivery to onboard science instruments. The sieving behavior of the testbed hardware should be similar to the Flight hardware for the results to be meaningful. The elastodynamic behavior of both sieves was studied analytically using the Rayleigh Ritz method in conjunction with classical plate theory. Finite element models were used to determine the mode shapes of both designs, and comparisons between the natural frequencies and mode shapes were made. The analysis predicts that the performance of the CMTB Thwacker will closely resemble the performance of the Flight Thwacker within the expected steady state operating regime. Excitations of the testbed hardware that will mimic the flight hardware were recommended, as were those that will improve the efficiency of the sieving process.

  13. Modal Analysis and Model Correlation of the Mir Space Station

    Science.gov (United States)

    Kim, Hyoung M.; Kaouk, Mohamed

    2000-01-01

    This paper will discuss on-orbit dynamic tests, modal analysis, and model refinement studies performed as part of the Mir Structural Dynamics Experiment (MiSDE). Mir is the Russian permanently manned Space Station whose construction first started in 1986. The MiSDE was sponsored by the NASA International Space Station (ISS) Phase 1 Office and was part of the Shuttle-Mir Risk Mitigation Experiment (RME). One of the main objectives for MiSDE is to demonstrate the feasibility of performing on-orbit modal testing on large space structures to extract modal parameters that will be used to correlate mathematical models. The experiment was performed over a one-year span on the Mir-alone and Mir with a Shuttle docked. A total of 45 test sessions were performed including: Shuttle and Mir thruster firings, Shuttle-Mir and Progress-Mir dockings, crew exercise and pushoffs, and ambient noise during night-to-day and day-to-night orbital transitions. Test data were recorded with a variety of existing and new instrumentation systems that included: the MiSDE Mir Auxiliary Sensor Unit (MASU), the Space Acceleration Measurement System (SAMS), the Russian Mir Structural Dynamic Measurement System (SDMS), the Mir and Shuttle Inertial Measurement Units (IMUs), and the Shuttle payload bay video cameras. Modal analysis was performed on the collected test data to extract modal parameters, i.e. frequencies, damping factors, and mode shapes. A special time-domain modal identification procedure was used on free-decay structural responses. The results from this study show that modal testing and analysis of large space structures is feasible within operational constraints. Model refinements were performed on both the Mir alone and the Shuttle-Mir mated configurations. The design sensitivity approach was used for refinement, which adjusts structural properties in order to match analytical and test modal parameters. To verify the refinement results, the analytical responses calculated using

  14. Modal analysis and geochemistry of two sandstones of the Bhander ...

    Indian Academy of Sciences (India)

    and tectonic setting interpretations are based on modal analysis and whole rock geochemistry. The average ... that major part of the sediments were derived from the granitic source area. The sandstone ...... The geochemical gap shown by trace and rare ... of the Council of Scientific and Industrial Research,. New Delhi, in ...

  15. Model Checking Is Static Analysis of Modal Logic

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis

    2010-01-01

    Flow Logic is an approach to the static analysis of programs that has been developed for functional, imperative and object-oriented programming languages and for concurrent, distributed, mobile and cryptographic process calculi. In this paper we extend it; to deal with modal logics and prove...

  16. Stabilization diagrams using operational modal analysis and sliding filters

    DEFF Research Database (Denmark)

    Olsen, Peter; Juul, Martin Ørum Ørhem; Tarpø, Marius Glindtvad

    2017-01-01

    This paper presents a filtering technique for doing effective operational modal analysis. The result of the filtering method is construction of stabilization diagram that clearly separates physical poles from spurious noise poles needed for unbiased fitting. A band pass filter is moved slowly over...

  17. Modal analysis of beam with piezoelectric sensors a actuators

    Directory of Open Access Journals (Sweden)

    Zemčík R.

    2007-10-01

    Full Text Available One dimensional finite element is developed for the analysis of structures with applied piezoelectric sensors and actuators, i.e. smart structures, mechanical behavior of which can be controlled in real-time. The element is based on Euler-Bernoulli theory and it assumes bilinear distribution of electric field potential. Mathematical model was implemented in MATLAB environment. Sensitivity analysis is carried out for the case of modal analysis with and without piezo patches.

  18. Model validity and frequency band selection in operational modal analysis

    Science.gov (United States)

    Au, Siu-Kui

    2016-12-01

    Experimental modal analysis aims at identifying the modal properties (e.g., natural frequencies, damping ratios, mode shapes) of a structure using vibration measurements. Two basic questions are encountered when operating in the frequency domain: Is there a mode near a particular frequency? If so, how much spectral data near the frequency can be included for modal identification without incurring significant modeling error? For data with high signal-to-noise (s/n) ratios these questions can be addressed using empirical tools such as singular value spectrum. Otherwise they are generally open and can be challenging, e.g., for modes with low s/n ratios or close modes. In this work these questions are addressed using a Bayesian approach. The focus is on operational modal analysis, i.e., with 'output-only' ambient data, where identification uncertainty and modeling error can be significant and their control is most demanding. The approach leads to 'evidence ratios' quantifying the relative plausibility of competing sets of modeling assumptions. The latter involves modeling the 'what-if-not' situation, which is non-trivial but is resolved by systematic consideration of alternative models and using maximum entropy principle. Synthetic and field data are considered to investigate the behavior of evidence ratios and how they should be interpreted in practical applications.

  19. Modal analysis of a stiffened toroidal shell sector

    International Nuclear Information System (INIS)

    Cerreta, R.; Di Pietro, E.; Pizzuto, A.

    1987-01-01

    This paper presents the results of the modal analysis of a sector of the toroidal vacuum vessel of a new experimental machine for research in the field of controlled thermonuclear fusion (FTU - Frascati Tokamak Upgrade). The vacuum vessel, one of the most critical components of the experimental device, consist of 12 stainless steel toroidal sectors, and it is designed to withstand pulsed electromagnetic loads during operation. Results of the modal analysis of the stiffened toroidal shell sector are compared and discussed with regard to the experimental data. Theoretical eigenvalues and eigenvectors have been predicted by means of ABAQUS finite element code. Experimental analysis has been carried out on a full scale model and natural frequencies have been measured. Satisfactory agreement between experimental and theoretical eigenvalues has been found

  20. Experimental modal analysis of components of the LHC experiments

    CERN Document Server

    Guinchard, M; Catinaccio, A; Kershaw, K; Onnela, A

    2007-01-01

    Experimental modal analysis of components of the LHC experiments is performed with the purpose of determining their fundamental frequencies, their damping and the mode shapes of light and fragile detector components. This process permits to confirm or replace Finite Element analysis in the case of complex structures (with cables and substructure coupling). It helps solving structural mechanical problems to improve the operational stability and determine the acceleration specifications for transport operations. This paper describes the hardware and software equipment used to perform a modal analysis on particular structures such as a particle detector and the method of curve fitting to extract the results of the measurements. This paper exposes also the main results obtained for the LHC Experiments.

  1. Operational modal analysis modeling, Bayesian inference, uncertainty laws

    CERN Document Server

    Au, Siu-Kui

    2017-01-01

    This book presents operational modal analysis (OMA), employing a coherent and comprehensive Bayesian framework for modal identification and covering stochastic modeling, theoretical formulations, computational algorithms, and practical applications. Mathematical similarities and philosophical differences between Bayesian and classical statistical approaches to system identification are discussed, allowing their mathematical tools to be shared and their results correctly interpreted. Many chapters can be used as lecture notes for the general topic they cover beyond the OMA context. After an introductory chapter (1), Chapters 2–7 present the general theory of stochastic modeling and analysis of ambient vibrations. Readers are first introduced to the spectral analysis of deterministic time series (2) and structural dynamics (3), which do not require the use of probability concepts. The concepts and techniques in these chapters are subsequently extended to a probabilistic context in Chapter 4 (on stochastic pro...

  2. Scattering of particles by deformed non-rotating black holes

    International Nuclear Information System (INIS)

    Pei, Guancheng; Bambi, Cosimo

    2015-01-01

    We study the excitation of axial quasi-normal modes of deformed non-rotating black holes by test particles and we compare the associated gravitational wave signal with that expected in general relativity from a Schwarzschild black hole. Deviations from standard predictions are quantified by an effective deformation parameter, which takes into account deviations from both the Schwarzschild metric and the Einstein equations. We show that, at least in the case of non-rotating black holes, it is possible to test the metric around the compact object, in the sense that the measurement of the gravitational wave spectrum can constrain possible deviations from the Schwarzschild solution. (orig.)

  3. Quantifying and managing uncertainty in operational modal analysis

    Science.gov (United States)

    Au, Siu-Kui; Brownjohn, James M. W.; Mottershead, John E.

    2018-03-01

    Operational modal analysis aims at identifying the modal properties (natural frequency, damping, etc.) of a structure using only the (output) vibration response measured under ambient conditions. Highly economical and feasible, it is becoming a common practice in full-scale vibration testing. In the absence of (input) loading information, however, the modal properties have significantly higher uncertainty than their counterparts identified from free or forced vibration (known input) tests. Mastering the relationship between identification uncertainty and test configuration is of great interest to both scientists and engineers, e.g., for achievable precision limits and test planning/budgeting. Addressing this challenge beyond the current state-of-the-art that are mostly concerned with identification algorithms, this work obtains closed form analytical expressions for the identification uncertainty (variance) of modal parameters that fundamentally explains the effect of test configuration. Collectively referred as 'uncertainty laws', these expressions are asymptotically correct for well-separated modes, small damping and long data; and are applicable under non-asymptotic situations. They provide a scientific basis for planning and standardization of ambient vibration tests, where factors such as channel noise, sensor number and location can be quantitatively accounted for. The work is reported comprehensively with verification through synthetic and experimental data (laboratory and field), scientific implications and practical guidelines for planning ambient vibration tests.

  4. Condition Monitoring Of Operating Pipelines With Operational Modal Analysis Application

    OpenAIRE

    Mironov Aleksey; Doronkin Pavel; Priklonsky Aleksander; Kabashkin Igor

    2015-01-01

    In the petroleum, natural gas and petrochemical industries, great attention is being paid to safety, reliability and maintainability of equipment. There are a number of technologies to monitor, control, and maintain gas, oil, water, and sewer pipelines. The paper focuses on operational modal analysis (OMA) application for condition monitoring of operating pipelines. Special focus is on the topicality of OMA for definition of the dynamic features of the pipeline (frequencies and mode shapes) i...

  5. Automated Modal Parameter Estimation for Operational Modal Analysis of Large Systems

    DEFF Research Database (Denmark)

    Andersen, Palle; Brincker, Rune; Goursat, Maurice

    2007-01-01

    In this paper the problems of doing automatic modal parameter extraction and how to account for large number of data to process are considered. Two different approaches for obtaining the modal parameters automatically using OMA are presented: The Frequency Domain Decomposition (FDD) technique and...

  6. Modal shapes optimization and feasibility analysis of NFAL platform

    Directory of Open Access Journals (Sweden)

    Bin WEI

    2017-08-01

    Full Text Available In order to avoid friction and scratching between the conveyor and the precision components when conveying object, an compact non-contact acoustic levitation prototype is designed, and the feasibility is theoretically and experimentally verified. The symmetry model is established through kinetic analysis with ANSYS. The modal and the coupled field computation at the central point of the transfer platform are simulated. The simulation results show that pure flexural or mixed flexural wave shapes appear with different wave numbers on the platform. Sweep frequency test is conducted on the compact platform prototype. The levitation experimental results confirm the feasibility of the ultrasound transfer process, the levitation frequency range and the mode of vibration. The theoretical and experimental results show that the optimal design of the modal and the carrying capacity of the driving platform is necessary according to different conditions. The research results provide a reference for the design of the mode and bandwidth of the ultrasonic levitation platform.

  7. Generalized modal analysis for closed-loop piezoelectric devices

    International Nuclear Information System (INIS)

    Giraud-Audine, Christophe; Giraud, Frédéric; Amberg, Michel; Lemaire-Semail, Betty

    2015-01-01

    Stress in a piezoelectric material can be controlled by imposing an electrical field. Thanks to feedback, this electrical field can be a function of some strain-related measurement so as to confer on the piezoelectric device a closed-loop macroscopic behaviour. In this paper we address the modelling of such a system by extending the modal decomposition methods to account for the closed loop. To do so, the boundary conditions are modified to include the electrical feedback circuit, hence allowing a closed-loop modal analysis. A case study is used to illustrate the theory and to validate it. The main advantage of the method is that design issues such as the coupling factor of the device and closed-loop stability are simultaneously captured. (paper)

  8. Modal testing and analysis of NOVA laser structures

    International Nuclear Information System (INIS)

    Burdick, R.B.; Weaver, H.J.; Pastrnak, J.W.

    1984-09-01

    NOVA, currently the world's most powerful laser system, is an ongoing project at the Lawrence Livermore National Laboratory in California. The project seeks to develop a feasible method of achieving controlled fusion reaction, initiated by multiple laser beams targeted on a tiny fuel pellet. The NOVA system consists of several large steel framed structures, the largest of which is the Target Chamber Tower. In conjunction with design engineers, the tower was first modelled and analyzed by sophisticated finite element techniques. A modal test was then conducted on the tower structure to evaluate its vibrational characteristics and seismic integrity as well as for general comparison to the finite element results. This paper will discuss the procedure used in the experimental modal analysis and the results obtained from that test

  9. Drifting plasmons in open two-dimensional channels: modal analysis

    International Nuclear Information System (INIS)

    Sydoruk, O

    2013-01-01

    Understanding the properties of plasmons in two-dimensional channels is important for developing methods of terahertz generation. This paper presents a modal analysis of plasmonic reflection in open channels supporting dc currents. As it shows, the plasmons can be amplified upon reflection if a dc current flows away from a conducting boundary; de-amplification occurs for the opposite current direction. The problem is solved analytically, based on a perturbation calculation, and numerically, and agreement between the methods is demonstrated. The power radiated by a channel is found to be negligible, and plasmon reflection in open channels is shown to be similar to that in closed channels. Based on this similarity, the oscillator designs developed earlier for closed channels could be applicable also for open ones. The results develop the modal-decomposition technique further as an instrument for the design of terahertz plasmonic sources. (paper)

  10. Modal analysis application for dynamic characterization of simple structures

    International Nuclear Information System (INIS)

    Pastorini, A.J.; Belinco, C.G.

    1987-01-01

    The knowledge of the dynamic characteristics of a structure helps to foresee the vibrating behaviour under operating conditions. The modal analysis techniques offer a method to perform the dynamic characterization of a studied structure from the vibration modes of such structure. A hammer provided with a loaded cell to excite a wide frequency band and accelerometer and, on the basis of a measurement of the transfer function at different points, various simple structures were given with a dynamic structures analysis (of the type of Fourier's rapidly transformation) and the results were compared with those obtained by other methods. Different fields where these techniques are applied, are also enumerated. (Author)

  11. Automated SEM Modal Analysis Applied to the Diogenites

    Science.gov (United States)

    Bowman, L. E.; Spilde, M. N.; Papike, James J.

    1996-01-01

    Analysis of volume proportions of minerals, or modal analysis, is routinely accomplished by point counting on an optical microscope, but the process, particularly on brecciated samples such as the diogenite meteorites, is tedious and prone to error by misidentification of very small fragments, which may make up a significant volume of the sample. Precise volume percentage data can be gathered on a scanning electron microscope (SEM) utilizing digital imaging and an energy dispersive spectrometer (EDS). This form of automated phase analysis reduces error, and at the same time provides more information than could be gathered using simple point counting alone, such as particle morphology statistics and chemical analyses. We have previously studied major, minor, and trace-element chemistry of orthopyroxene from a suite of diogenites. This abstract describes the method applied to determine the modes on this same suite of meteorites and the results of that research. The modal abundances thus determined add additional information on the petrogenesis of the diogenites. In addition, low-abundance phases such as spinels were located for further analysis by this method.

  12. Progressive reduction of the thermal wall system by modal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari, A.; Meslem, A.; Bounif, A.; Kadi, L. [Universite des Sciences et de la Technologie, Oran (Algeria)

    1993-12-31

    A reduction method of thermal systems called ``progress`` using the modal Analysis is presented. It allows to do, at each time of simulation, a synthesis information in the system evolution. Consequently, the limited number of descriptive and significant parameters (proper modes), can produce some extremely useful indication about dynamic evolution. However this method can eliminate proper modes of which the energetic contribution will be neglected or amortized. Some examples were studied, showing the efficiency of this method by reducing the computing time, as well as, having high precision on predicted dynamic response over time of simulation. (Authors). 4 refs., 4 figs.

  13. Modal Analysis of MARS Solar Panel and Planar Vibrations

    Science.gov (United States)

    Simonyan, Andranik; Williams, R. Brett

    2007-01-01

    This slide presentation reviews the modal analysis of MARS solar panels and the planar vibrations. Included are views of the solar panels mock-up assembly, a view of the test seup,a view of the plot from the test, with the raw numbers of the frequencies in Hz values with the mode number, the spatial acceleration plots of Center sub panel at resonant frequencies, predictions from the Finite element models, an explanation of the two test that were done on the plate and the results from both tests,

  14. Investigation of Apple Vibration Characteristics Using Finite Element Modal Analysis

    Directory of Open Access Journals (Sweden)

    R Mirzaei

    2013-02-01

    Full Text Available The most important quality indicator of fruits is the flesh firmness which is well correlated to their young’s modulus. In this research variation of vibration characteristics (shape modes, natural frequency of apple due to change of material characteristics (density, young's models, Poisson ratio and apple volume was investigated using Finite Element simulation. An image processing technique was used to obtain an unsymmetrical and non-spherical geometric model of apple. The exact three-dimensional shape of the fruit was created by determining the coordinates of apple surface and forming uneven rotational curvatures. Modal analysis with no boundary constraints has been applied. The first 20 Eigen frequencies and the corresponding mode shape were determined. Six rigid body modes possess zero resonant frequency which is related to the degree of freedom of a rigid body in space indicated the validity of finite element model. The modal analysis results showed that resonant frequency increased by increasing young's modulus of the fruit, while it decreased by increasing apple density. First mode torsion has a mean resonant frequency of 584 Hz. Variations of natural frequency due to change in young's modulus, density, and Poisson ratio were 80%, 11% and 4%, respectively. Coefficient of variation of resonant frequency in response to changing young's modulus was 2-3 times of that of density which shows the greatest effect of young modulus changes on natural frequency of fruits. Consequently with determination of fruits' natural frequency, their young modulus and firmness can be estimated.

  15. Nonlinear modal analysis in NPP dynamics: a proposal

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2005-07-01

    We propose and briefly suggest how to apply the analytical tools of nonlinear modal analysis (NMA) to problems of nuclear reactor kinetics, NPP dynamics, and NPP instrumentation and control. The proposed method is closely related with recent approaches by modal analysis using the reactivity matrix with feedbacks to couple neutron kinetics with thermal hydraulics in the reactors core. A nonlinear system of ordinary differential equations for mode amplitudes is obtained, projecting the dynamic equations of a model of NPP onto the eigenfunctions of a suitable adjoint operator. A steady state solution of the equations is taken as a reference, and the behaviour of transient solutions in some neighbourhood of the steady state solution is studied by an extension of Liapunov's First Method that enables to cope directly with the non-linear terms in the dynamics. In NPP dynamics these differential equations for the mode amplitudes are of polynomial type of low degree A few dominant modes can usually be identified. These mode amplitudes evolve almost independently of the other modes, more slowly and tending to slave the other mode amplitudes. Using asymptotic methods, it is possible to calculate a closed form analytical approximation to the response to finite amplitude perturbations from the given steady spatial pattern (the origin of the space of mode amplitudes).When there is finite amplitude instability, the method allows us to calculate the threshold amplitude as a well defined function of system's parameters. This is a most significant accomplishment that the other methods cannot afford

  16. Condition Monitoring Of Operating Pipelines With Operational Modal Analysis Application

    Directory of Open Access Journals (Sweden)

    Mironov Aleksey

    2015-12-01

    Full Text Available In the petroleum, natural gas and petrochemical industries, great attention is being paid to safety, reliability and maintainability of equipment. There are a number of technologies to monitor, control, and maintain gas, oil, water, and sewer pipelines. The paper focuses on operational modal analysis (OMA application for condition monitoring of operating pipelines. Special focus is on the topicality of OMA for definition of the dynamic features of the pipeline (frequencies and mode shapes in operation. The research was conducted using two operating laboratory models imitated a part of the operating pipeline. The results of finite-element modeling, identification of pipe natural modes and its modification under the influence of virtual failure are discussed. The work considers the results of experimental research of dynamic behavior of the operating pipe models using one of OMA techniques and comparing dynamic properties with the modeled data. The study results demonstrate sensitivity of modal shape parameters to modification of operating pipeline technical state. Two strategies of pipeline repair – with continuously condition-based monitoring with proposed technology and without such monitoring, was discussed. Markov chain reliability models for each strategy were analyzed and reliability improvement factor for proposed technology of monitoring in compare with traditional one was evaluated. It is resumed about ability of operating pipeline condition monitoring by measuring dynamic deformations of the operating pipe and OMA techniques application for dynamic properties extraction.

  17. Modal analysis of pre and post impacted nano composite laminates

    Directory of Open Access Journals (Sweden)

    R. Velmurugan

    Full Text Available Modal analysis is carried out on pre and post impacted nano composite laminates. The laminates are prepared using 3, 5 and 8 layers of 610gsm glass woven roving mats(WRM with epoxy resin and montmorillonite(MMT clay content is varied from 1% to 5%. Impulse hammer technique is used to find natural frequency and damping factor of laminates. Medium velocity impact tests are conducted by using a gas gun. The vibration responses of natural frequency and damping factor are obtained and are studied for laminates with all edges clamped boundary conditions. Results show considerable improvement in natural frequency and damping factor due to nano clay addition. It is also seen that the nano clay controls the delamination due to impact loading.

  18. Reducing the uncertainty in robotic machining by modal analysis

    Science.gov (United States)

    Alberdi, Iñigo; Pelegay, Jose Angel; Arrazola, Pedro Jose; Ørskov, Klaus Bonde

    2017-10-01

    The use of industrial robots for machining could lead to high cost and energy savings for the manufacturing industry. Machining robots offer several advantages respect to CNC machines such as flexibility, wide working space, adaptability and relatively low cost. However, there are some drawbacks that are preventing a widespread adoption of robotic solutions namely lower stiffness, vibration/chatter problems and lower accuracy and repeatability. Normally due to these issues conservative cutting parameters are chosen, resulting in a low material removal rate (MRR). In this article, an example of a modal analysis of a robot is presented. For that purpose the Tap-testing technology is introduced, which aims at maximizing productivity, reducing the uncertainty in the selection of cutting parameters and offering a stable process free from chatter vibrations.

  19. Modal analysis of electromechanical oscillations in electrical power systems; Analisis modal de oscilaciones electromecanicas en sistemas electricos de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Calderon-Guizar, J.G [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: jgcg@iie.org.mx

    2008-10-15

    The presence of electromechanical oscillations in any electrical power system is a typical characteristic of this kind of systems. Provided the damping associated with these oscillations lies above of a minimum specified value, the occurrence of these oscillations is not considered as a threat to the system operation. This paper focuses the attention on the application of modal analysis for assessing the dynamical behavior of a power system subjected to small disturbances for different operating conditions and transmission system topologies, as well. The reported results indicate, that modal analysis enables a straight identification of the causes that contribute negatively to the damping of the electromechanical modes. [Spanish] La presencia de oscilaciones electromecanicas en cualquier Sistema Electrico de Potencia (SEP) es una caracteristica propia de estos sistemas. Mientras el amortiguamiento asociado con este tipo de oscilaciones se encuentre dentro de los limites considerados como aceptables para la operacion continua de este tipo de sistemas, el surgimiento de estas no se considera una amenaza para la operacion segura del SEP. El presente articulo, centra su atencion en la aplicacion del analisis modal para evaluar el comportamiento dinamico de un SEP ante la ocurrencia de disturbios de magnitud pequena para diferentes topologias y condiciones de operacion. Los resultados reportados indican, que la aplicacion del analisis modal permite la identificacion directa de las causas que contribuyen en forma negativa al amortiguamiento asociado con los modos electromecanicos, asi como la ubicacion mas adecuada de controles que contribuyan a mejorar el amortiguamiento de los mismos.

  20. Polynomial modal analysis of lamellar diffraction gratings in conical mounting.

    Science.gov (United States)

    Randriamihaja, Manjakavola Honore; Granet, Gérard; Edee, Kofi; Raniriharinosy, Karyl

    2016-09-01

    An efficient numerical modal method for modeling a lamellar grating in conical mounting is presented. Within each region of the grating, the electromagnetic field is expanded onto Legendre polynomials, which allows us to enforce in an exact manner the boundary conditions that determine the eigensolutions. Our code is successfully validated by comparison with results obtained with the analytical modal method.

  1. Static Structural and Modal Analysis of Gas Turbine Blade

    Science.gov (United States)

    Ranjan Kumar, Ravi; Pandey, K. M., Prof.

    2017-08-01

    Gas turbine is one of the most versatile items of turbo machinery nowadays. It is used in different modes such as power generation, oil and gas, process plants, aviation, domestic and related small industries. This paper is based on the problems concerning blade profile selection, material selection and turbine rotor blade vibration that seriously impact the induced stress-deformation and structural functioning of developmental gas turbine engine. In this paper for generating specific power by rotating blade at specific RPM, blade profile and material has been decided by static structural analysis. Gas turbine rotating blade RPM is decided by Modal Analysis so that the natural frequency of blade should not match with the excitation frequency. For the above blade profile has been modeled in SOLIDWORKS and analysis has been done in ANSYS WORKBENCH 14. Existing NACA6409 profile has been selected as base model and then it is modified by bending it through 72.5° and 145°. Hence these three different blade profiles have been analyzed for three different materials viz. Super Alloy X, Nimonic 80A and Inconel 625 at three different speed viz. 20000, 40000 and 60000RPM. It is found that NACA6409 with 72.5° bent gives best result for all material at all speed. Among all the material Inconel 625 gives best result. Hence Blade of Inconel 625 having 72.5° bent profile is the best combination for all RPM.

  2. Automated modal parameter estimation using correlation analysis and bootstrap sampling

    Science.gov (United States)

    Yaghoubi, Vahid; Vakilzadeh, Majid K.; Abrahamsson, Thomas J. S.

    2018-02-01

    The estimation of modal parameters from a set of noisy measured data is a highly judgmental task, with user expertise playing a significant role in distinguishing between estimated physical and noise modes of a test-piece. Various methods have been developed to automate this procedure. The common approach is to identify models with different orders and cluster similar modes together. However, most proposed methods based on this approach suffer from high-dimensional optimization problems in either the estimation or clustering step. To overcome this problem, this study presents an algorithm for autonomous modal parameter estimation in which the only required optimization is performed in a three-dimensional space. To this end, a subspace-based identification method is employed for the estimation and a non-iterative correlation-based method is used for the clustering. This clustering is at the heart of the paper. The keys to success are correlation metrics that are able to treat the problems of spatial eigenvector aliasing and nonunique eigenvectors of coalescent modes simultaneously. The algorithm commences by the identification of an excessively high-order model from frequency response function test data. The high number of modes of this model provides bases for two subspaces: one for likely physical modes of the tested system and one for its complement dubbed the subspace of noise modes. By employing the bootstrap resampling technique, several subsets are generated from the same basic dataset and for each of them a model is identified to form a set of models. Then, by correlation analysis with the two aforementioned subspaces, highly correlated modes of these models which appear repeatedly are clustered together and the noise modes are collected in a so-called Trashbox cluster. Stray noise modes attracted to the mode clusters are trimmed away in a second step by correlation analysis. The final step of the algorithm is a fuzzy c-means clustering procedure applied to

  3. Non linear structures seismic analysis by modal synthesis

    International Nuclear Information System (INIS)

    Aita, S.; Brochard, D.; Guilbaud, D.; Gibert, R.J.

    1987-01-01

    The structures submitted to a seismic excitation, may present a great amplitude response which induces a non linear behaviour. These non linearities have an important influence on the response of the structure. Even in this case (local shocks) the modal synthesis method remains attractive. In this paper we will present the way of taking into account, a local non linearity (shock between structures) in the seismic response of structures, by using the modal synthesis method [fr

  4. Usage of modal synthesis method with condensation in rotor

    Directory of Open Access Journals (Sweden)

    Zeman V.

    2008-11-01

    Full Text Available The paper deals with mathematical modelling of vibration and modal analysis of rotors composed of a flexible shaft and several flexible disks. The shaft is modelled as a one dimensional continuum whereon flexible disks modelled as a three dimensional continuum are rigid mounted to shaft. The presented approach allows to introduce continuously distributed centrifugal and gyroscopic effects. The finite element method was used for shaft and disks discretization. The modelling of such flexible multi-body rotors with large DOF number is based on the system decomposition into subsystems and on the modal synthesis method with condensation. Lower vibration mode shapes of the mutually uncoupled and non-rotating subsystems are used for creation of the rotor condensed mathematical model. An influence of the different level of a rotor condensation model on the accuracy of calculated eigenfrequencies and eigenvectors is discussed.

  5. Is Synthesizing MRI Contrast Useful for Inter-modality Analysis?

    DEFF Research Database (Denmark)

    Iglesias, Juan Eugenio; Konukoglu, Ender; Zikic, Darko

    2013-01-01

    Availability of multi-modal magnetic resonance imaging (MRI) databases opens up the opportunity to synthesize different MRI contrasts without actually acquiring the images. In theory such synthetic images have the potential to reduce the amount of acquisitions to perform certain analyses. However...

  6. Recursive subspace identification for in flight modal analysis of airplanes

    OpenAIRE

    De Cock , Katrien; Mercère , Guillaume; De Moor , Bart

    2006-01-01

    International audience; In this paper recursive subspace identification algorithms are applied to track the modal parameters of airplanes on-line during test flights. The ability to track changes in the damping ratios and the influence of the forgetting factor are studied through simulations.

  7. Analysis of modal shift in South Africa: A qualitative investigation

    CSIR Research Space (South Africa)

    Venter, Karien

    2013-07-01

    Full Text Available The qualitative investigation into factors facilitating modal shift formed part of a larger research study that was conducted by the CSIR for the National Department of Transport. The aim of the study was to understand the factors that are most...

  8. Nonrotating black hole in a post-Newtonian tidal environment

    International Nuclear Information System (INIS)

    Taylor, Stephanne; Poisson, Eric

    2008-01-01

    We examine the motion and tidal dynamics of a nonrotating black hole placed within a post-Newtonian external spacetime. The black hole's gravity is described accurately to all orders in Gm/c 2 r, where m is the black-hole mass and r is the distance to the black hole. The tidal perturbation created by the external environment is treated as a small perturbation. At a large distance from the black hole, the gravitational field of the external distribution of matter is assumed to be sufficiently weak to be adequately described by the (first) post-Newtonian approximation to general relativity. There, the black hole is treated as a monopole contribution to the total gravitational field. There exists an overlap in the domains of validity of each description, and the black-hole and post-Newtonian metrics are matched in the overlap. The matching procedure produces (i) a justification of the statement that a nonrotating black hole is a post-Newtonian monopole; (ii) a complete characterization of the coordinate transformation between the inertial, barycentric frame and the accelerated, black-hole frame; (iii) the equations of motion for the black hole; and (iv) the gravito-electric and gravito-magnetic tidal fields acting on the black hole. We first calculate the equations of motion and tidal fields by making no assumptions regarding the nature of the post-Newtonian environment; this could contain a continuous distribution of matter (so as to model a galactic core) or any number of condensed bodies. We next specialize our discussion to a situation in which the black hole is a member of a post-Newtonian two-body system. As an application of our results, we examine the geometry of the deformed event horizon and calculate the tidal heating of the black hole, the rate at which it acquires mass as a result of its tidal interaction with the companion body.

  9. Non normal modal analysis of oscillations in boiling water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Suarez-Antola, Roberto, E-mail: roberto.suarez@miem.gub.uy [Ministerio de Industria, Energia y Mineria (MIEM), Montevideo (Uruguay); Flores-Godoy, Jose-Job, E-mail: job.flores@ibero.mx [Universidad Iberoamericana (UIA), Mexico, DF (Mexico). Dept. de Fisica Y Matematicas

    2013-07-01

    The first objective of the present work is to construct a simple reduced order model for BWR stability analysis, combining a two nodes nodal model of the thermal hydraulics with a two modes modal model of the neutronics. Two coupled non-linear integral-differential equations are obtained, in terms of one global (in phase) and one local (out of phase) power amplitude, with direct and cross feedback reactivities given as functions of thermal hydraulics core variables (void fractions and temperatures). The second objective is to apply the effective life time approximation to further simplify the nonlinear equations. Linear approximations for the equations of the amplitudes of the global and regional modes are derived. The linearized equation for the amplitude of the global mode corresponds to a decoupled and damped harmonic oscillator. An analytical closed form formula for the damping coefficient, as a function of the parameters space of the BWR, is obtained. The coefficient changes its sign (with the corresponding modification in the decay ratio) when a stability boundary is crossed. This produces a supercritical Hopf bifurcation, with the steady state power of the reactor as the bifurcation parameter. However, the linearized equation for the amplitude of the regional mode corresponds always to an over-damped and always coupled (with the amplitude of the global mode) harmonic oscillator, for every set of possible values of core parameters (including the steady state power of the reactor) in the framework of the present mathematical model. The equation for the above mentioned over damped linear oscillator is closely connected with a non-normal operator. Due to this connection, there could be a significant transient growth of some solutions of the linear equation. This behavior allows a significant shrinking of the basin of attraction of the equilibrium state. The third objective is to apply the above approach to partially study the stability of the regional mode and

  10. Advances in Modal Analysis Using a Robust and Multiscale Method

    Science.gov (United States)

    Picard, Cécile; Frisson, Christian; Faure, François; Drettakis, George; Kry, Paul G.

    2010-12-01

    This paper presents a new approach to modal synthesis for rendering sounds of virtual objects. We propose a generic method that preserves sound variety across the surface of an object at different scales of resolution and for a variety of complex geometries. The technique performs automatic voxelization of a surface model and automatic tuning of the parameters of hexahedral finite elements, based on the distribution of material in each cell. The voxelization is performed using a sparse regular grid embedding of the object, which permits the construction of plausible lower resolution approximations of the modal model. We can compute the audible impulse response of a variety of objects. Our solution is robust and can handle nonmanifold geometries that include both volumetric and surface parts. We present a system which allows us to manipulate and tune sounding objects in an appropriate way for games, training simulations, and other interactive virtual environments.

  11. Advances in Modal Analysis Using a Robust and Multiscale Method

    Directory of Open Access Journals (Sweden)

    Frisson Christian

    2010-01-01

    Full Text Available Abstract This paper presents a new approach to modal synthesis for rendering sounds of virtual objects. We propose a generic method that preserves sound variety across the surface of an object at different scales of resolution and for a variety of complex geometries. The technique performs automatic voxelization of a surface model and automatic tuning of the parameters of hexahedral finite elements, based on the distribution of material in each cell. The voxelization is performed using a sparse regular grid embedding of the object, which permits the construction of plausible lower resolution approximations of the modal model. We can compute the audible impulse response of a variety of objects. Our solution is robust and can handle nonmanifold geometries that include both volumetric and surface parts. We present a system which allows us to manipulate and tune sounding objects in an appropriate way for games, training simulations, and other interactive virtual environments.

  12. Modal analysis of wave propagation in dispersive media

    Science.gov (United States)

    Abdelrahman, M. Ismail; Gralak, B.

    2018-01-01

    Surveys on wave propagation in dispersive media have been limited since the pioneering work of Sommerfeld [Ann. Phys. 349, 177 (1914), 10.1002/andp.19143491002] by the presence of branches in the integral expression of the wave function. In this article a method is proposed to eliminate these critical branches and hence to establish a modal expansion of the time-dependent wave function. The different components of the transient waves are physically interpreted as the contributions of distinct sets of modes and characterized accordingly. Then, the modal expansion is used to derive a modified analytical expression of the Sommerfeld precursor improving significantly the description of the amplitude and the oscillating period up to the arrival of the Brillouin precursor. The proposed method and results apply to all waves governed by the Helmholtz equations.

  13. Modal analysis of temperature feedback in oscillations induced by xenon

    International Nuclear Information System (INIS)

    Passos, E.M. dos.

    1976-01-01

    The flux oscillations induced by Xenon distribution in homogeneous thermal reactors are studied treating the space dependence through the modal expansion technique and the stability limits against power oscillations and spatial oscillations are determined. The effect of the feedbacks due to Xenon and temperature coefficient on the linear stability of the free system is investigated employing several number of terms in the transient expansion, considering the various sizes of the reactor. The heat transfer model considered includes one term due to cooling proportional to the temperature. A PWR model reactor is utilized for numerical calculations. It is found that a slightly higher temperature feedback coefficient is necessary for stability against power oscillations when larger number of terms in the transient modal expansion is maintained. (author)

  14. Alternate modal combination methods in response spectrum analysis

    International Nuclear Information System (INIS)

    Wang, Y.K.; Bezler, P.

    1989-01-01

    In piping analyses using the response spectrum method Square Root of the Sum of the Squares (SRSS) with clustering between closely spaced modes is the combination procedure most commonly used to combine between the modal response components. This procedure is simple to apply and normally yields conservative estimates of the time history results. The purpose of this study is to investigate alternate methods to combine between the modal response components. These methods are mathematically based to properly account for the combination between rigid and flexible modal responses as well as closely spaced modes. The methods are those advanced by Gupta, Hadjian and Lindley-Yow to address rigid response modes and the Double Sum Combination (DSC) method and the Complete Quadratic Combination (CQC) method to account for closely spaced modes. A direct comparison between these methods as well as the SRSS procedure is made by using them to predict the response of six piping systems. For two piping systems thirty-three earthquake records were considered to account for the impact of variations in the characteristics of the excitation. The results provided by each method are compared to the corresponding time history estimates of results as well as to each other. The degree of conservatism associated with each method is characterized. 7 refs., 4 figs., 2 tabs

  15. Alternate modal combination methods in response spectrum analysis

    International Nuclear Information System (INIS)

    Bezler, P.; Curreri, J.R.; Wang, Y.K.; Gupta, A.K.

    1990-10-01

    In piping analyses using the response spectrum method Square Root of the Sum of the Squares (SRSS) with clustering between closely spaced modes is the combination procedure most commonly used to combine between the modal response components. This procedure is simple to apply and normally yields conservative estimates of the time history results. The purpose of this study is to investigate alternate methods to combine between the modal response components. These methods are mathematically based to properly account for the combination between rigid and flexible modal responses as well as closely spaced modes. The methods are those advanced by Gupta, Hadjian and Lindely-Yow to address rigid response modes and the Double Sum Combination (DSC) method and the Complete Quadratic Combination (CQC) method to account for closely spaced modes. A direct comparison between these methods as well as the SRSS procedure is made by using them to predict the response of six piping systems. The results provided by each method are compared to the corresponding time history estimates of results as well as to each other. The degree of conservatism associated with each method is characterized. 19 refs., 16 figs., 10 tabs

  16. Eliminating the Influence of Harmonic Components in Operational Modal Analysis

    DEFF Research Database (Denmark)

    Jacobsen, Niels-Jørgen; Andersen, Palle; Brincker, Rune

    2007-01-01

    structures, in contrast, are subject inherently to deterministic forces due to the rotating parts in the machinery. These forces are seen as harmonic components in the responses, and their influence should be eliminated before extracting the modes in their vicinity. This paper describes a new method based...... on the well-known Enhanced Frequency Domain Decomposition (EFDD) technique for eliminating these harmonic components in the modal parameter extraction process. For assessing the quality of the method, various experiments were carried out where the results were compared with those obtained with pure stochastic...

  17. A study on identification of nonlinear structure by experimental modal analysis

    International Nuclear Information System (INIS)

    Sone, Akira; Suzuki, Kohei; Nakamura, Hajime.

    1990-01-01

    In this paper, identification techniques based on the experimental modal analysis for the equivalent modal parameters of nonlinear structures are examined from a practical viewpoint. First, using a simple cantilever model with gap or friction at the supported end, the gain characteristics of transfer function are evaluated through the sinusoidal sweep test and random wave test. Second, the equivalent modal parameters such as natural frequency and damping ratio are estimated by two types of identification techniques: ARMA (autoregressive/moving average) model fitting and curve fitting with iterative calculations. From the comparison of the response of the model obtained by the random excitation test and numerical calculation using the equivalent modal parameters, it has been clarified that the ARMA model fitting can be applied to linearized modal parameter identification for nonlinear structures. (author)

  18. A modal analysis of flexible aircraft dynamics with handling qualities implications

    Science.gov (United States)

    Schmidt, D. K.

    1983-01-01

    A multivariable modal analysis technique is presented for evaluating flexible aircraft dynamics, focusing on meaningful vehicle responses to pilot inputs and atmospheric turbulence. Although modal analysis is the tool, vehicle time response is emphasized, and the analysis is performed on the linear, time-domain vehicle model. In evaluating previously obtained experimental pitch tracking data for a family of vehicle dynamic models, it is shown that flexible aeroelastic effects can significantly affect pitch attitude handling qualities. Consideration of the eigenvalues alone, of both rigid-body and aeroelastic modes, does not explain the simulation results. Modal analysis revealed, however, that although the lowest aeroelastic mode frequency was still three times greater than the short-period frequency, the rigid-body attitude response was dominated by this aeroelastic mode. This dominance was defined in terms of the relative magnitudes of the modal residues in selected vehicle responses.

  19. Predicting wind-induced vibrations of high-rise buildings using unsteady CFD and modal analysis

    KAUST Repository

    Zhang, Yue; Habashi, Wagdi G (Ed); Khurram, Rooh Ul Amin

    2015-01-01

    This paper investigates the wind-induced vibration of the CAARC standard tall building model, via unsteady Computational Fluid Dynamics (CFD) and a structural modal analysis. In this numerical procedure, the natural unsteady wind in the atmospheric

  20. MIDAS phase II. A program for the modal analysis of structures

    International Nuclear Information System (INIS)

    Durrans, R.F.

    1980-10-01

    The application of Modal Analysis to the experimental characterisation of structures is described. A program MIDAS (Modal Identification for the Dynamic Analysis of Structures) has been developed at B.N.L. to perform this function and this report presents a full description of its use. The structures within the coolant circuits of nuclear reactors must be designed to withstand large flow and acoustic forces. (U.K.)

  1. Vibration analysis of the piping system using the modal analysis method, 1

    International Nuclear Information System (INIS)

    Fujikawa, Takeshi; Kurohashi, Michiya; Inoue, Yoshio

    1975-01-01

    Modal analysis method was developed for the vibration analysis of piping system in nuclear or chemical plants, with finite element theory, and verified by sinusoidal vibration method. The natural vibration equation for pipings was derived with stiffness, attenuation and mass matrices, and eigenvalues are obtained with usual method, then the forced vibration equation for pipings was derived with the same manner, and the special solutions are given by modal method from the eigenvalues of the natural vibration equation. Three simple piping models (one, two and three dimensional) were made, and the natural vibration frequency was measured with forced input from an electrical dynamic shaker and a sound speaker. The experimental values of natural vibration frequency showed good agreement with the results by the analytical method. Therefore the theoretical approach for piping system vibration was proved to be valid. (Iwase, T.)

  2. Mechanistic Insights into Human Brain Impact Dynamics through Modal Analysis

    Science.gov (United States)

    Laksari, Kaveh; Kurt, Mehmet; Babaee, Hessam; Kleiven, Svein; Camarillo, David

    2018-03-01

    Although concussion is one of the greatest health challenges today, our physical understanding of the cause of injury is limited. In this Letter, we simulated football head impacts in a finite element model and extracted the most dominant modal behavior of the brain's deformation. We showed that the brain's deformation is most sensitive in low frequency regimes close to 30 Hz, and discovered that for most subconcussive head impacts, the dynamics of brain deformation is dominated by a single global mode. In this Letter, we show the existence of localized modes and multimodal behavior in the brain as a hyperviscoelastic medium. This dynamical phenomenon leads to strain concentration patterns, particularly in deep brain regions, which is consistent with reported concussion pathology.

  3. Modal Analysis Based on the Random Decrement Transform

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Brincker, Rune; Ibrahim, S. R.

    of this paper is to present a state-of-the-art description of the Random Decrement technique where the statistical theory is outlined and examples are given. But also new results such as estimation of frequency response functions and quality assessment are introduced. Special attention is given......During the last years several papers utilizing the Random Decrement transform as a basis for extraction of modal parameters from the response of linear systems subjected to unknown ambient loads have been presented. Although the Random Decrement technique was developed in a decade starting from...... the introduktion in 1968 the technique seems still to be attractive. This is probably due to the simplicity and the speed of the algorithm and the fact that the theory of the technique has been extended by introducing statistical measures such as correlation functions or spectral densities. The purpose...

  4. Automated computation of autonomous spectral submanifolds for nonlinear modal analysis

    Science.gov (United States)

    Ponsioen, Sten; Pedergnana, Tiemo; Haller, George

    2018-04-01

    We discuss an automated computational methodology for computing two-dimensional spectral submanifolds (SSMs) in autonomous nonlinear mechanical systems of arbitrary degrees of freedom. In our algorithm, SSMs, the smoothest nonlinear continuations of modal subspaces of the linearized system, are constructed up to arbitrary orders of accuracy, using the parameterization method. An advantage of this approach is that the construction of the SSMs does not break down when the SSM folds over its underlying spectral subspace. A further advantage is an automated a posteriori error estimation feature that enables a systematic increase in the orders of the SSM computation until the required accuracy is reached. We find that the present algorithm provides a major speed-up, relative to numerical continuation methods, in the computation of backbone curves, especially in higher-dimensional problems. We illustrate the accuracy and speed of the automated SSM algorithm on lower- and higher-dimensional mechanical systems.

  5. Numerical Investigation on Detection of Prestress Losses in a Prestressed Concrete Slab by Modal Analysis

    Science.gov (United States)

    Kovalovs, A.; Rucevskis, S.; Akishin, P.; Kolupajevs, J.

    2017-10-01

    The paper presents numerical results of loss of prestress in the reinforced prestressed precast hollow core slabs by modal analysis. Loss of prestress is investigated by the 3D finite element method, using ANSYS software. In the numerical examples, variables initial stresses were introduced into seven-wire stress-relieved strands of the concrete slabs. The effects of span and material properties of concrete on the modal frequencies of the concrete structure under initial stress were studied. Modal parameters computed from the finite element models were compared. Applicability and effectiveness of the proposed method was investigated.

  6. Live-Axis Turning for the Fabrication of Non-Rotationally Symmetric Optics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this proposal is to develop a new method to create Non-Rotationally Symmetric (NRS) surfaces that overcomes the limitations of the current techniques and...

  7. On the axially symmetric non-rotating vacuum solutions of Rosen's equations

    International Nuclear Information System (INIS)

    Bozhkov, Y.

    1990-10-01

    It is shown that all axially symmetric nonrotating solutions of Rosen's field equations can be expressed in terms of two harmonic functions. It is also shown that the total energy of Rosen's metric is Mc 2 . (author). 8 refs

  8. Comparison of modal spectral and non-linear time history analysis of a piping system

    International Nuclear Information System (INIS)

    Gerard, R.; Aelbrecht, D.; Lafaille, J.P.

    1987-01-01

    A typical piping system of the discharge line of the chemical and volumetric control system, outside the containment, between the penetration and the heat exchanger, an operating power plant was analyzed using four different methods: Modal spectral analysis with 2% constant damping, modal spectral analysis using ASME Code Case N411 (PVRC damping), linear time history analysis, non-linear time history analysis. This paper presents an estimation of the conservatism of the linear methods compared to the non-linear analysis. (orig./HP)

  9. Residual mass considerations in modal analysis of large dynamic structural systems

    International Nuclear Information System (INIS)

    Shulman, J.S.; Day, J.P.

    1991-01-01

    Industry guidelines have specified that the seismic evaluation of Moderate and High Hazard Department of Energy (DOE) facilities be accomplished by use of dynamic analysis. The recommended approach is elastic response spectrum dynamic analysis to evaluate the elastic system demand on facility components. The application of modal response spectrum analysis to the seismic evaluation of nuclear facility structures, systems and equipment involves approximations due to limitations on the number of modes typically addressed in the complete dynamic solution. A simplified approach for achieving improved rigor in accounting for responses of the higher frequency modes in a modal response spectrum analysis is demonstrated

  10. Modal Analysis of In-Wheel Motor-Driven Electric Vehicle Based on Bond Graph Theory

    Directory of Open Access Journals (Sweden)

    Di Tan

    2017-01-01

    Full Text Available A half-car vibration model of an electric vehicle driven by rear in-wheel motors was developed using bond graph theory and the modular modeling method. Based on the bond graph model, modal analysis was carried out to study the vibration characteristics of the electric vehicle. To verify the effectiveness of the established model, the results were compared to ones computed on the ground of modal analysis and Newton equations. The comparison shows that the vibration model of the electric vehicle based on bond graph theory not only is able to better compute the natural frequency but also can easily determine the deformation mode, momentum mode, and other isomorphism modes and describe the dynamic characteristics of an electric vehicle driven by in-wheel motors more comprehensively than other modal analysis methods.

  11. Validation of VARK learning modalities questionnaire using Rasch analysis

    Science.gov (United States)

    Fitkov-Norris, E. D.; Yeghiazarian, A.

    2015-02-01

    This article discusses the application of Rasch analysis to assess the internal validity of a four sub-scale VARK (Visual, Auditory, Read/Write and Kinaesthetic) learning styles instrument. The results from the analysis show that the Rasch model fits the majority of the VARK questionnaire data and the sample data support the internal validity of the four sub-constructs at 1% level of significance for all but one item. While this suggests that the instrument could potentially be used as a predictor for a person's learning preference orientation, further analysis is necessary to confirm the invariability of the instrument across different user groups across factors such as gender, age, educational and cultural background.

  12. Completely automated modal analysis procedure based on the combination of different OMA methods

    Science.gov (United States)

    Ripamonti, Francesco; Bussini, Alberto; Resta, Ferruccio

    2018-03-01

    In this work a completely automated output-only Modal Analysis procedure is presented and all its benefits are listed. Based on the merging of different Operational Modal Analysis methods and a statistical approach, the identification process has been improved becoming more robust and giving as results only the real natural frequencies, damping ratios and mode shapes of the system. The effect of the temperature can be taken into account as well, leading to the creation of a better tool for automated Structural Health Monitoring. The algorithm has been developed and tested on a numerical model of a scaled three-story steel building present in the laboratories of Politecnico di Milano.

  13. Modal analysis of spindle of grinder machine based on ANSYS

    Directory of Open Access Journals (Sweden)

    HE Chaocong

    2015-10-01

    Full Text Available The object of research is to a certain type grinding wheel spindle for which a 3D model of the spindle is established by SolidWorks software and ANSYS software is imported for model analysis.Natural frequency,vibration type and critical speed of the spindle model are obtained and the resulting data are scientifically analyzed.The results show that the spindle structure is reasonable,the machining accuracy can be ensured and the position where the most severe deformation and the main shaft fatigue fracture may occur can be found out,which also provide the theoretical basis for further optimization design and precision control.

  14. Modal analysis of spindle of grinder machine based on ANSYS

    OpenAIRE

    HE Chaocong; LIU Peipei; YAN Chunfei; WANG Muhuan; LIN Jun

    2015-01-01

    The object of research is to a certain type grinding wheel spindle for which a 3D model of the spindle is established by SolidWorks software and ANSYS software is imported for model analysis.Natural frequency,vibration type and critical speed of the spindle model are obtained and the resulting data are scientifically analyzed.The results show that the spindle structure is reasonable,the machining accuracy can be ensured and the position where the most severe deformation and the main shaft fat...

  15. Modal analysis of spontaneous emission in a planar microcavity

    International Nuclear Information System (INIS)

    Rigneault, H.; Monneret, S.

    1996-01-01

    A complete set of cavity modes in planar dielectric microcavities is presented which naturally includes guided modes. We show that most of these orthonormal fields can be derived from a coherent superposition of plane waves incoming on the stack from the air and from the substrate. Spontaneous emission of a dipole located inside the microcavity is analyzed, in terms of cavity modes. Derivation of the radiation pattern in the air and in the substrate is presented. The power emitted into the guided modes is also determined. Finally, a numerical analysis of the radiative properties of an erbium atom located in a Fabry-Pacute erot multilayer dielectric microcavity is investigated. We show that a large amount of light is emitted into the guided modes of the structure, in spite of the Fabry-Pacute erot resonance, which increases the spontaneous emission rate in a normal direction. copyright 1996 The American Physical Society

  16. Modal analysis of pool door in water tank

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kang Soo; Jeong, Kyeong Hoon; Park, Chan Gook; Koo, In Soo [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    A pool door is installed at the chase of the pool gate by means of an overhead crane in the building of a research reactor. The principal function of the pool door, which is located between the reactor pool and service pool, is to separate the reactor pool from the service pool for the maintenance and/or the removal of the equipment either in the reactor pool or service pool. The pool door consists of stainless steel plates supported by structural steel frames and sealing components. The pool door is equipped with double inflatable gaskets. The configuration of the pool door is shown in Figure 1. The FEM analysis and theoretical calculation by the formula were performed to evaluate the natural frequency for the pool door in the water. The results from the two methods were compared.

  17. Comparative analysis of success of psoriasis treatment with standard therapeutic modalities and balneotherapy.

    Science.gov (United States)

    Baros, Duka Ninković; Gajanin, Vesna S; Gajanin, Radoslav B; Zrnić, Bogdan

    2014-01-01

    Psoriasis is a chronic, inflammatory, immune-mediated skin disease. In addition to standard therapeutic modalities (antibiotics, cytostatics, phototherapy, photochemotherapy and retinoids), nonstandard methods can be used in the treatment of psoriasis. This includes balneotherapy which is most commonly used in combination with therapeutic resources. The aim of this research was to determine the length of remission of psoriasis in patients treated with standard therapeutic modalities, balneotherapy, and combined treatment (standard therapeutic modalities and balneotherapy). The study analyzed 60 adult patients, of both sexes, with different clinical forms of psoriasis, who were divided into three groups according to the applied therapeutic modalities: the first group (treated with standard therapeutic modalities), the second group (treated with balneotherapy) and the third group (treated with combined therapy-standard methods therapy and balneotherapy). The Psoriasis Area and Severity Index was determined in first, third and sixth week of treatment for all patients. The following laboratory analysis were performed and monitored: C reactive protein, iron with total iron binding capacity, unsaturated iron binding capacity and ferritin, uric acid, rheumatoid factors and antibodies to streptolysin O in the first and sixth week of treatment. The average length of remission in patients treated with standard therapeutic modalities and in those treated with balneotherapy was 1.77 +/- 0.951 months and 1.79 +/- 0.918 months, respectively. There was a statistically significant difference in the duration of remission between the patients treated with combination therapy and patients treated with standard therapeutic modalities (p = 0.019) and balneotherapy (p = 0.032). The best results have been achieved when the combination therapy was administered.

  18. Modal analysis of spent fuel cask for WWER-1000 reactors

    International Nuclear Information System (INIS)

    Azimfar, S. A.; Kazemi, A.

    2011-01-01

    The Spent Fuel Assemblies of WWER-1000 reactors are planned to be transported by special containers which are supposed to be designed in a manner to stand against vibrations and impacts in order to protect the spent fuel from any possible damage. The vibration opposition of these containers shall be far beyond the critical resonance, because the resonances about the natural frequency of the structure will cause the enhancement of its oscillation range and may end with its disintegration. Determination of the amounts of natural frequencies and their mode shape can be achieved by vibration analyzing methods. The amount of the natural frequency of any structure crucially depends on its shape, material and lean points as well as the amount of the loads and the type of these loads. Due to the fact that the Spent Fuel Casks used for transportation in nuclear power plants in Russian Federation are TK-13 type and the pieces of information released are negligible, the scientists in Russia are working on the design and analysis of a new type made up of composite Material. In the presented paper the cask of spent fuel of TK-13 is modeled by ANSYS at 10.0 and ten natural frequency modes have been calculated, followed by the comparison of this result with the composite cask.

  19. Modal analysis of cable-stayed UHPC bridge

    Directory of Open Access Journals (Sweden)

    Tej Petr

    2017-01-01

    Full Text Available This paper deals with the dynamic analysis of cable-stayed UHPC bridge over the Vltava river near town Melnik in Czech Republic, Europe. Bridge serves for pedestrians and cyclists. This work aims to familiarize the reader with dynamic calculations carried out and the results obtained, describing the dynamic properties of proposed bridge. The construction of bridge is designed as a cable-stayed structure with prestressed bridge deck consisting of prefabricated UHPC panels and reversed “V” shaped steel pylon with height of approximately 40 meters. The deck is anchored using 24 steel hangers in one row in a steel pylon - 17 ropes in the main span and 7 cables on the other side. Range of the main span is 99.18 meters and the secondary span is 31.9 m. Deck width is 4.5 meters with 3.0 meters passing space. The bridge is designed for the possibility of passage of vehicles weighting up to 3.5 tonnes. Deck panels are made of UHPC with reinforcement. At the edge of the bridge on the side of the shorter span the bridge deck is firmly connected with abutment and on the other deck it is stored using a pair of sliding bearings.

  20. A modal analysis of carbon nanotube using elastic network model

    International Nuclear Information System (INIS)

    Kim, Min Hyeok; Seo, Sang Jae; Lim, Byeong Soo; Choi, Jae Boong; Kim, Moon Ki; Liu, Wing Kam

    2012-01-01

    Although it is widely known that both size and chirality play significant roles in vibration behaviors of single walled carbon nanotubes (SWCNTs), there haven't been yet enough studies specifying the relationship between structure and vibration mode shape of SWCNTs. We have analyzed the chirality and length dependence of SWCNT by using normal mode analysis based elastic network model in which all interatomic interactions of the given SWCNTs structure are represented by a network of linear spring connections. As this method requires relatively short computation time compared to molecular dynamics simulation, we can efficiently analyze vibration behavior of SWCNTs. To ensure the relationship between SWCNT structure and its vibration mode shapes, we simulated more than one hundred SWCNTs having different types of chirality and length. Results indicated that the first two major mode shapes are bending and breathing. The minimum length of nanotube for maintaining the bending mode does not depend on chirality but on its diameter. Our simulations pointed out that there is a critical aspect ratio between diameter and length to determine vibration mode shapes, and it can be empirically formulated as a function of nanotube length and diameter. Therefore, uniformity control is the most important premise in order to utilize vibration features of SWCNTs. It is also expected that the obtained vibration aspect will play an important role in designing nanotube based devices such as resonators and sensors more accurately

  1. Using Enhanced Frequency Domain Decomposition as a Robust Technique to Harmonic Excitation in Operational Modal Analysis

    DEFF Research Database (Denmark)

    Jacobsen, Niels-Jørgen; Andersen, Palle; Brincker, Rune

    2006-01-01

    The presence of harmonic components in the measured responses is unavoidable in many applications of Operational Modal Analysis. This is especially true when measuring on mechanical structures containing rotating or reciprocating parts. This paper describes a new method based on the popular...... agreement is found and the method is proven to be an easy-to-use and robust tool for handling responses with deterministic and stochastic content....... Enhanced Frequency Domain Decomposition technique for eliminating the influence of these harmonic components in the modal parameter extraction process. For various experiments, the quality of the method is assessed and compared to the results obtained using broadband stochastic excitation forces. Good...

  2. Stability and time-domain analysis of the dispersive tristability in microresonators under modal coupling

    Science.gov (United States)

    Dumeige, Yannick; Féron, Patrice

    2011-10-01

    Coupled nonlinear resonators have potential applications for the integration of multistable photonic devices. The dynamic properties of two coupled-mode nonlinear microcavities made of Kerr material are studied by linear stability analysis. Using a suitable combination of the modal coupling rate and the frequency detuning, it is possible to obtain configurations where a hysteresis loop is included inside other bistable cycles. We show that a single resonator with two modes both linearly and nonlinearly coupled via the cross-Kerr effect can have a multistable behavior. This could be implemented in semiconductor nonlinear whispering-gallery-mode microresonators under modal coupling for all optical signal processing or ternary optical logic applications.

  3. Stability and time-domain analysis of the dispersive tristability in microresonators under modal coupling

    International Nuclear Information System (INIS)

    Dumeige, Yannick; Feron, Patrice

    2011-01-01

    Coupled nonlinear resonators have potential applications for the integration of multistable photonic devices. The dynamic properties of two coupled-mode nonlinear microcavities made of Kerr material are studied by linear stability analysis. Using a suitable combination of the modal coupling rate and the frequency detuning, it is possible to obtain configurations where a hysteresis loop is included inside other bistable cycles. We show that a single resonator with two modes both linearly and nonlinearly coupled via the cross-Kerr effect can have a multistable behavior. This could be implemented in semiconductor nonlinear whispering-gallery-mode microresonators under modal coupling for all optical signal processing or ternary optical logic applications.

  4. Meaning Making through Multiple Modalities in a Biology Classroom: A Multimodal Semiotics Discourse Analysis

    Science.gov (United States)

    Jaipal, Kamini

    2010-01-01

    The teaching of science is a complex process, involving the use of multiple modalities. This paper illustrates the potential of a multimodal semiotics discourse analysis framework to illuminate meaning-making possibilities during the teaching of a science concept. A multimodal semiotics analytical framework is developed and used to (1) analyze the…

  5. The new airfoil model NACA0015, modal analysis and flutter properties

    Czech Academy of Sciences Publication Activity Database

    Kozánek, Jan; Vlček, Václav; Zolotarev, Igor

    2017-01-01

    Roč. 46, June (2017), s. 698-706 ISSN 0307-904X Institutional support: RVO:61388998 Keywords : aeroelasticity * subsonic flow * self-excited vibration * modal analysis * kinematics Subject RIV: BI - Acoustics OBOR OECD: Applied mechanics Impact factor: 2.350, year: 2016 http://www.sciencedirect.com/science/article/pii/S0307904X1730135X

  6. Advantages and Drawbacks of Applying Periodic Time-Variant Modal Analysis to Spur Gear Dynamics

    DEFF Research Database (Denmark)

    Pedersen, Rune; Santos, Ilmar; Hede, Ivan Arthur

    2010-01-01

    to ensure sufficient accuracy of the results. The method of time-variant modal analysis is applied, and the changes in the fundamental and the parametric resonance frequencies as a function of the rotational speed of the gears, are found. By obtaining the stationary and parametric parts of the time...... of applying the methodology to wind turbine gearboxes are addressed and elucidated....

  7. Multi-parameters sensitivity analysis of natural vibration modal for steel arch bridge

    Directory of Open Access Journals (Sweden)

    WANG Ying

    2014-02-01

    Full Text Available Because of the vehicle loads and environmental factors,the behaviors of bridge structure in service is becoming deterioration.The modal parameters are important indexes of structure,so sensitivity analysis of natural vibration is an important way to evaluate the behavior of bridge structure.In this paper,using the finite element software Ansys,calculation model of a steel arch bridge was built,and the natural vibration modals were obtained.In order to compare the different sensitivity of material parameters which may affect the natural vibration modal,5 factors were chosen to perform the calculation.The results indicated that different 5 factors had different sensitivity.The leading factor was elastic modulus of arch rib,and the elastic modulus of suspender had little effect to the sensitivity.Another argument was the opposite sensitivity effect happened between the elastic modulus and density of the material.

  8. Wandering spleen with gastric volvulus and intestinal non-rotation in an adult male patient.

    Science.gov (United States)

    Ooka, Minako; Kohda, Eiichi; Iizuka, Yuo; Nagamoto, Masashi; Ishii, Tomotaka; Saida, Yoshihisa; Shimizu, Norikazu; Gomi, Tatsuya

    2013-01-01

    We report an extremely rare case of wandering spleen (WS) complicated with gastric volvulus and intestinal non-rotation in a male adult. A 22-year-old man who had been previously treated for Wilson disease was admitted with severe abdominal pain. Radiological findings showed WS in the midline of the pelvic area. The stomach was mesenteroaxially twisted and intestinal non-rotation was observed. Radiology results did not show any evidence of splenic or gastrointestinal (GI) infarction. Elective emergency laparoscopy confirmed WS and intestinal non-rotation; however, gastric volvulus was not observed. It was suspected that the stomach had untwisted when gastric and laparoscopic tubes were inserted. Surgery is strongly recommended for WS because of the high risk of serious complications; however, some asymptomatic adult patients are still treated conservatively, such as the patient in this study. The present case is reported with reference to the literature.

  9. Wandering spleen with gastric volvulus and intestinal non-rotation in an adult male patient

    International Nuclear Information System (INIS)

    Ooka, Minako; Kohda, Eiichi; Iizuka, Yuo; Nagamoto, Masashi; Ishii, Tomotaka; Saida, Yoshihisa; Shimizu, Norikazu; Gomi, Tatsuya

    2013-01-01

    We report an extremely rare case of wandering spleen (WS) complicated with gastric volvulus and intestinal non-rotation in a male adult. A 22-year-old man who had been previously treated for Wilson disease was admitted with severe abdominal pain. Radiological findings showed WS in the midline of the pelvic area. The stomach was mesenteroaxially twisted and intestinal non-rotation was observed. Radiology results did not show any evidence of splenic or gastrointestinal (GI) infarction. Elective emergency laparoscopy confirmed WS and intestinal non-rotation; however, gastric volvulus was not observed. It was suspected that the stomach had untwisted when gastric and laparoscopic tubes were inserted. Surgery is strongly recommended for WS because of the high risk of serious complications; however, some asymptomatic adult patients are still treated conservatively, such as the patient in this study. The present case is reported with reference to the literature

  10. Comparative Investigation on Modal analysis of LM25 Aluminium alloy with other Aluminim alloys using Finite element analysis software

    Science.gov (United States)

    Arunkumar, S.; Baskaralal, V. P. M.; Muthuraman, V.

    2017-03-01

    The rudimentary steps of the modal analysis and simulation are carried out. The modal analysis is carried out on the different Aluminum Alloys cantilever beam. The cantilever beam is designed in the graphical environment of the ANSYS. The cantilever beam was fine-tuned on one end with all degree of liberation on this end were taken, beam cannot move and rotate. Mode shapes and natural frequencies are premeditated in platforms ANSYS with arithmetical formulation of the direct solver including the block Lanczos method. Aluminum alloys are widely utilized in much application due to their estimable weight to vigor property. Many examination works have been distributed out to make developments the mechanical properties of aluminum alloys. The composition of alloying elements plays a consequential role in deciding the properties of an alloy. In this study a numerical analysis implement i.e., finite element analysis (FEA) is utilized. The work obtainable in this paper is aimed at the study of effect of modal analysis of different aluminum alloys. The modeling and analysis is carried out utilizing ANSYS FEA software. A modal analysis is carried out to understand the modes of frequency demeanor of the material considered. The modal analysis play a vital role in the design of components subjected to high vibration.

  11. Using experimental modal analysis to assess the behaviour of timber elements

    Science.gov (United States)

    Kouroussis, Georges; Fekih, Lassaad Ben; Descamps, Thierry

    2018-03-01

    Timber frameworks are one of the most important and widespread types of structures. Their configurations and joints are usually complex and require a high level of craftsmanship to assemble. In the field of restoration, a good understanding of the structural behaviour is necessary and is often based on assessment techniques dedicated to wood characterisation. This paper presents the use of experimental modal analysis for finite element updating. To do this, several timber beams in a free supported condition were analysed in order to extract their bending natural characteristics (frequency, damping and mode shapes). Corresponding ABAQUS finite element models were derived which included the effects of local defects (holes, cracks and wood nodes), moisture and structural decay. To achieve the modal updating, additional simulations were performed in order to study the sensitivity of the mechanical parameters. With the intent to estimate their mechanical properties, a procedure of modal updating was carried out in MatLab with a Python script. This was created to extract the modal information from the ABAQUS modal analysis results to be compared with the experimental results. The updating was based on a minimum of unconstrained multivariable function using a derivative-free method. The objective function was selected from the conventional comparison tools (absolute or relative frequency difference, and/or modal assurance criterion). This testing technique was used to determine the dynamic mechanical properties of timber beams, such as the anisotropic Young's Moduli and damping ratio. To verify the modulus, a series of static 4-point bending tests and STS04 classifications were conducted. The results also revealed that local defects have a negligible influence on natural frequencies. The results demonstrate that this assessment tool offers an effective method to obtain the mechanical properties of timber elements, especially when on-site and non-destructive techniques are

  12. Charged Massive Particle’s Tunneling from Charged Nonrotating Microblack Hole

    Directory of Open Access Journals (Sweden)

    M. J. Soleimani

    2016-01-01

    Full Text Available In the tunneling framework of Hawking radiation, charged massive particle’s tunneling in charged nonrotating TeV-scale black hole is investigated. To this end, we consider natural cutoffs as a minimal length, a minimal momentum, and a maximal momentum through a generalized uncertainty principle. We focus on the role played by these natural cutoffs on the luminosity of charged nonrotating microblack hole by taking into account the full implications of energy and charge conservation as well as the backscattered radiation.

  13. MANGO – Modal Analysis for Grid Operation: A Method for Damping Improvement through Operating Point Adjustment

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhenyu; Zhou, Ning; Tuffner, Francis K.; Chen, Yousu; Trudnowski, Daniel J.; Diao, Ruisheng; Fuller, Jason C.; Mittelstadt, William A.; Hauer, John F.; Dagle, Jeffery E.

    2010-10-18

    Small signal stability problems are one of the major threats to grid stability and reliability in the U.S. power grid. An undamped mode can cause large-amplitude oscillations and may result in system breakups and large-scale blackouts. There have been several incidents of system-wide oscillations. Of those incidents, the most notable is the August 10, 1996 western system breakup, a result of undamped system-wide oscillations. Significant efforts have been devoted to monitoring system oscillatory behaviors from measurements in the past 20 years. The deployment of phasor measurement units (PMU) provides high-precision, time-synchronized data needed for detecting oscillation modes. Measurement-based modal analysis, also known as ModeMeter, uses real-time phasor measurements to identify system oscillation modes and their damping. Low damping indicates potential system stability issues. Modal analysis has been demonstrated with phasor measurements to have the capability of estimating system modes from both oscillation signals and ambient data. With more and more phasor measurements available and ModeMeter techniques maturing, there is yet a need for methods to bring modal analysis from monitoring to actions. The methods should be able to associate low damping with grid operating conditions, so operators or automated operation schemes can respond when low damping is observed. The work presented in this report aims to develop such a method and establish a Modal Analysis for Grid Operation (MANGO) procedure to aid grid operation decision making to increase inter-area modal damping. The procedure can provide operation suggestions (such as increasing generation or decreasing load) for mitigating inter-area oscillations.

  14. Linearised dynamics and non-modal instability analysis of an impinging under-expanded supersonic jet

    Science.gov (United States)

    Karami, Shahram; Stegeman, Paul C.; Theofilis, Vassilis; Schmid, Peter J.; Soria, Julio

    2018-04-01

    Non-modal instability analysis of the shear layer near the nozzle of a supersonic under-expanded impinging jet is studied. The shear layer instability is considered to be one of the main components of the feedback loop in supersonic jets. The feedback loop is observed in instantaneous visualisations of the density field where it is noted that acoustic waves scattered by the nozzle lip internalise as shear layer instabilities. A modal analysis describes the asymptotic limit of the instability disturbances and fails to capture short-time responses. Therefore, a non-modal analysis which allows the quantitative description of the short-time amplification or decay of a disturbance is performed by means of a local far-field pressure pulse. An impulse response analysis is performed which allows a wide range of frequencies to be excited. The temporal and spatial growths of the disturbances in the shear layer near the nozzle are studied by decomposing the response using dynamic mode decomposition and Hilbert transform analysis. The short-time response shows that disturbances with non-dimensionalised temporal frequencies in the range of 1 to 4 have positive growth rates in the shear layer. The Hilbert transform analysis shows that high non-dimensionalised temporal frequencies (>4) are dampened immediately, whereas low non-dimensionalised temporal frequencies (analysis show that spatial frequencies between 1 and 3 have positive spatial growth rates. Finally, the envelope of the streamwise velocity disturbances reveals the presence of a convective instability.

  15. Modal spectral analysis of piping: Determination of the significant frequency range

    International Nuclear Information System (INIS)

    Geraets, L.H.

    1981-01-01

    This paper investigates the influence of the number of modes on the response of a piping system in a dynamic modal spectral analysis. It shows how the analysis can be limited to a specific frequency range of the pipe (independent of the frequency range of the response spectrum), allowing cost reduction without loss in accuracy. The 'missing mass' is taken into account through an original technique. (orig./HP)

  16. Modal analysis applied to rotor balancing: two relevant technical aspects; Analisis modal aplicado al balanceo de rotores: dos aspectos tecnicos relevantes

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre Romano, Jorge E.; Preciado Delgado, Eduardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1991-12-31

    In applying the modal analysis to rotor balancing, it is frequent to find technical matters that are hardly developed in text books or that can only be deducted through a profound and complex study. For this reason, an engineer dedicated to the practice that wishes to deepen in the subject of rotor balancing, can hardly understand these matters, unless they are developed with the specific orientation that relate them with the balancing practice. In this paper two of these subjects related to the definition and recollection of modal parameters are presented: a) the fundamental form of the polar diagrams of response, that can be perfectly circular in certain cases and b) the relationship that exists among the modal forms of a rotor and the distribution of weights that must be placed to balance them in a given way. [Espanol] Al aplicar el analisis modal al balanceo de rotores, es frecuente encontrar temas tecnicos que dificilmente se desarrollan en los libros de texto, o que solo pueden deducirse mediante un estudio profundo y complejo. Por esta razon, un ingeniero dedicado a la practica que desee profundizar en el tema de balanceo de rotores, dificilmente podra comprender estos temas, a no ser que estos sean desarrollados con la orientacion especifica que los relacionen con la practica del balanceo. En este trabajo se presentan dos de esos temas relacionados con la definicion y obtencion de los parametros modales: a) la forma fundamental de los diagramas polares de respuesta, que puede ser circular perfecta en ciertos casos, y b) la relacion que existe entre las formas modales de un rotor y la distribucion de pesos que se deben colocar para balancear un modo dado.

  17. Modal analysis applied to rotor balancing: two relevant technical aspects; Analisis modal aplicado al balanceo de rotores: dos aspectos tecnicos relevantes

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre Romano, Jorge E; Preciado Delgado, Eduardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1992-12-31

    In applying the modal analysis to rotor balancing, it is frequent to find technical matters that are hardly developed in text books or that can only be deducted through a profound and complex study. For this reason, an engineer dedicated to the practice that wishes to deepen in the subject of rotor balancing, can hardly understand these matters, unless they are developed with the specific orientation that relate them with the balancing practice. In this paper two of these subjects related to the definition and recollection of modal parameters are presented: a) the fundamental form of the polar diagrams of response, that can be perfectly circular in certain cases and b) the relationship that exists among the modal forms of a rotor and the distribution of weights that must be placed to balance them in a given way. [Espanol] Al aplicar el analisis modal al balanceo de rotores, es frecuente encontrar temas tecnicos que dificilmente se desarrollan en los libros de texto, o que solo pueden deducirse mediante un estudio profundo y complejo. Por esta razon, un ingeniero dedicado a la practica que desee profundizar en el tema de balanceo de rotores, dificilmente podra comprender estos temas, a no ser que estos sean desarrollados con la orientacion especifica que los relacionen con la practica del balanceo. En este trabajo se presentan dos de esos temas relacionados con la definicion y obtencion de los parametros modales: a) la forma fundamental de los diagramas polares de respuesta, que puede ser circular perfecta en ciertos casos, y b) la relacion que existe entre las formas modales de un rotor y la distribucion de pesos que se deben colocar para balancear un modo dado.

  18. Averaged cov-driven subspace identification for modal analysis of a modified troposkien blade with displacement measurement

    DEFF Research Database (Denmark)

    Najafi, Nadia; Panah, Mohammad Esmail Aryaee; Schmidt Paulsen, Uwe

    2015-01-01

    An operational modal analysis study has been carried out on a 1- kW, vertical-axis wind turbine rotor blade, using a stereo vision technique. Numerical simulation has also been carried out and results were compared to classical modal analysis and OMA results. The displacement time series used...

  19. MODAL ANALYSIS OF REAL TIMBER FRAME HOUSES WITH DIFFERENT INSULATION MATERIALS

    Directory of Open Access Journals (Sweden)

    Marcin Szczepański

    2016-09-01

    Full Text Available The aim of this article is to present the results of a numerical modal analysis of two actual structures of timber frame buildings and the different behaviour due to the used insulation material. One model of the timber structure was filled with mineral wool, while the other with polyurethane foam. During the modal analysis, eigenvalues for both models have been determined. The results of the analysis clearly show the increase of stiffness and damping properties of skeletal constructions achieved by the use of polyurethane foam as the skeleton filling. The numerical model was based on prior experimental test on real scale single frame elements, therefore the result can be assumed to be adequate.

  20. The Review of Visual Analysis Methods of Multi-modal Spatio-temporal Big Data

    Directory of Open Access Journals (Sweden)

    ZHU Qing

    2017-10-01

    Full Text Available The visual analysis of spatio-temporal big data is not only the state-of-art research direction of both big data analysis and data visualization, but also the core module of pan-spatial information system. This paper reviews existing visual analysis methods at three levels:descriptive visual analysis, explanatory visual analysis and exploratory visual analysis, focusing on spatio-temporal big data's characteristics of multi-source, multi-granularity, multi-modal and complex association.The technical difficulties and development tendencies of multi-modal feature selection, innovative human-computer interaction analysis and exploratory visual reasoning in the visual analysis of spatio-temporal big data were discussed. Research shows that the study of descriptive visual analysis for data visualizationis is relatively mature.The explanatory visual analysis has become the focus of the big data analysis, which is mainly based on interactive data mining in a visual environment to diagnose implicit reason of problem. And the exploratory visual analysis method needs a major break-through.

  1. Sustained turbulence and magnetic energy in non-rotating shear flows

    DEFF Research Database (Denmark)

    Nauman, Farrukh; Blackman, Eric G.

    2017-01-01

    From numerical simulations, we show that non-rotating magnetohydrodynamic shear flows are unstable to finite amplitude velocity perturbations and become turbulent, leading to the growth and sustenance of magnetic energy, including large scale fields. This supports the concept that sustained...... magnetic energy from turbulence is independent of the driving mechanism for large enough magnetic Reynolds numbers....

  2. Technique for description of nonrotational excited states in a semiphenomenological nuclear theory

    International Nuclear Information System (INIS)

    Krutov, V.A.

    1985-01-01

    A non-standard technique for microscopic description of excited nonrotational states is considered; it is suitable for inseparable force application. Besides, an additional binding operator, mixing quasi-particle excitations and E1-resonance states, is considered. Instead of the standard technique of state ''collectivization'' of the random phase approximation type it is used the so-called ''method of bound amplitudes''

  3. Operational modal analysis and wavelet transformation for damage identification in wind turbine blades

    DEFF Research Database (Denmark)

    Ulriksen, Martin Dalgaard; Tcherniak, Dmitri; Kirkegaard, Poul Henning

    2014-01-01

    The presented study demonstrates an application of a previously proposed modal and wavelet analysis-based damage identification method to a wind turbine blade. A trailing edge debonding was introduced to a SSP 34m blade mounted on a test rig. Operational modal analysis (OMA) was conducted to obtain...... are captured in the CWT by significantly magnified transform coefficients, thus providing combined damage detection, localization, and size assessment. It was found that due to the nature of the proposed method, the value of the identification results highly depends on the number of employed measurement points....... Since only a limited number of measurement points were utilized in the experiments, valid damage identification can only be obtained when employing high-frequency modes....

  4. Evaluation of freeze-thaw durability of pervious concrete by use of operational modal analysis

    DEFF Research Database (Denmark)

    Lund, M.S.M.; Hansen, K. K.; Brincker, R.

    2018-01-01

    It is well-known that laboratory testing of pervious concrete's freeze-thaw performance is too harsh and does not agree well with field observations. The most commonly used laboratory freeze-thaw test method for pervious concrete is similar to that used for conventional concrete even though...... the void structure of the two materials is completely different. In the present study, a new freeze-thaw test method for pervious concrete is suggested and tested on one baseline mix, with three different contents of entrained air. The evaluation of freeze-thaw damage on pervious concrete beams...... was evaluated from the decrease in mass and from operational modal analysis which provides an accurate determination of the change in natural frequencies with freeze-thaw exposure. Operational modal analysis was also used to determine the Young's modulus, shear modulus, and Poisson's ratio of the pervious...

  5. Thermal modal analysis of novel non-pneumatic mechanical elastic wheel based on FEM and EMA

    Science.gov (United States)

    Zhao, Youqun; Zhu, Mingmin; Lin, Fen; Xiao, Zhen; Li, Haiqing; Deng, Yaoji

    2018-01-01

    A combination of Finite Element Method (FEM) and Experiment Modal Analysis (EMA) have been employed here to characterize the structural dynamic response of mechanical elastic wheel (ME-Wheel) operating under a specific thermal environment. The influence of high thermal condition on the structural dynamic response of ME-Wheel is investigated. The obtained results indicate that the EMA results are in accordance with those obtained using the proposed Finite Element (FE) model, indicting the high reliability of this FE model applied in analyzing the modal of ME-Wheel working under practical thermal environment. It demonstrates that the structural dynamic response of ME-Wheel operating under a specific thermal condition can be predicted and evaluated using the proposed analysis method, which is beneficial for the dynamic optimization design of the wheel structure to avoid tire temperature related vibration failure and improve safety of tire.

  6. Material model of pelvic bone based on modal analysis: a study on the composite bone.

    Science.gov (United States)

    Henyš, Petr; Čapek, Lukáš

    2017-02-01

    Digital models based on finite element (FE) analysis are widely used in orthopaedics to predict the stress or strain in the bone due to bone-implant interaction. The usability of the model depends strongly on the bone material description. The material model that is most commonly used is based on a constant Young's modulus or on the apparent density of bone obtained from computer tomography (CT) data. The Young's modulus of bone is described in many experimental works with large variations in the results. The concept of measuring and validating the material model of the pelvic bone based on modal analysis is introduced in this pilot study. The modal frequencies, damping, and shapes of the composite bone were measured precisely by an impact hammer at 239 points. An FE model was built using the data pertaining to the geometry and apparent density obtained from the CT of the composite bone. The isotropic homogeneous Young's modulus and Poisson's ratio of the cortical and trabecular bone were estimated from the optimisation procedure including Gaussian statistical properties. The performance of the updated model was investigated through the sensitivity analysis of the natural frequencies with respect to the material parameters. The maximal error between the numerical and experimental natural frequencies of the bone reached 1.74 % in the first modal shape. Finally, the optimised parameters were matched with the data sheets of the composite bone. The maximal difference between the calibrated material properties and that obtained from the data sheet was 34 %. The optimisation scheme of the FE model based on the modal analysis data provides extremely useful calibration of the FE models with the uncertainty bounds and without the influence of the boundary conditions.

  7. Modal analysis of inter-area oscillations using the theory of normal modes

    Energy Technology Data Exchange (ETDEWEB)

    Betancourt, R.J. [School of Electromechanical Engineering, University of Colima, Manzanillo, Col. 28860 (Mexico); Barocio, E. [CUCEI, University of Guadalajara, Guadalajara, Jal. 44480 (Mexico); Messina, A.R. [Graduate Program in Electrical Engineering, Cinvestav, Guadalajara, Jal. 45015 (Mexico); Martinez, I. [State Autonomous University of Mexico, Toluca, Edo. Mex. 50110 (Mexico)

    2009-04-15

    Based on the notion of normal modes in mechanical systems, a method is proposed for the analysis and characterization of oscillatory processes in power systems. The method is based on the property of invariance of modal subspaces and can be used to represent complex power system modal behavior by a set of decoupled, two-degree-of-freedom nonlinear oscillator equations. Using techniques from nonlinear mechanics, a new approach is outlined, for determining the normal modes (NMs) of motion of a general n-degree-of-freedom nonlinear system. Equations relating the normal modes and the physical velocities and displacements are developed from the linearized system model and numerical issues associated with the application of the technique are discussed. In addition to qualitative insight, this method can be utilized in the study of nonlinear behavior and bifurcation analyses. The application of these procedures is illustrated on a planning model of the Mexican interconnected system using a quadratic nonlinear model. Specifically, the use of normal mode analysis as a basis for identifying modal parameters, including natural frequencies and damping ratios of general, linear systems with n degrees of freedom is discussed. Comparisons to conventional linear analysis techniques demonstrate the ability of the proposed technique to extract the different oscillation modes embedded in the oscillation. (author)

  8. Modal analysis and nonlinear characterization of an airborne power ultrasonic transducer with rectangular plate radiator.

    Science.gov (United States)

    Andrés, R R; Acosta, V M; Lucas, M; Riera, E

    2018-01-01

    Some industrial processes like particle agglomeration or food dehydration among others can be enhanced by the use of power ultrasonic technologies. These technologies are based on an airborne power ultrasonic transducer (APUT) constituted by a pre-stressed Langevin-type transducer, a mechanical amplifier and an extensive plate radiator. In order to produce the desired effects in industrial processing, the transducer has to vibrate in an extensional mode driving an extensive radiator in the desired flexural mode with high amplitude displacements. Due to the generation of these high amplitude displacements in the radiator surfaces, non-linear effects like frequency shifts, hysteresis or modal interactions, among others, may be produced in the transducer behavior. When any nonlinear effect appears, when applying power, the stability and efficiency of this ultrasonic technology decreases, and the transducer may be damaged depending on the excitation power level and the nature of the nonlinearity. In this paper, an APUT with flat rectangular radiator is presented, as the active part of an innovative system with stepped reflectors. The nonlinear behavior of the APUT has been characterized numerically and experimentally in case of the modal analysis and experimentally in the case of dynamic analysis. According to the results obtained after the experiments, no modal interactions are expected, nor do other nonlinear effects. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. On minimizing the influence of the noise tail of correlation functions in operational modal analysis

    DEFF Research Database (Denmark)

    Tarpø, Marius; Olsen, Peter; Amador, Sandro

    2017-01-01

    on the identification results (random errors) when the noise tail is included in the identification. On the other hand, if the correlation function is truncated too much, then important information is lost. In other to minimize this error, a suitable truncation based on manual inspection of the correlation function......In operational modal analysis (OMA) correlation functions are used by all classical time-domain modal identification techniques that uses the impulse response function (free decays) as primary data. However, the main difference between the impulse response and the correlation functions estimated...... from the operational responses is that the latter present a higher noise level. This is due to statistical errors in the estimation of the correlation function and it causes random noise in the end of the function and this is called the noise tail. This noise might have significant influence...

  10. Modal analysis of blade bending and torsional shaft coupling by component mode synthesis

    International Nuclear Information System (INIS)

    Vare, C.

    1995-10-01

    The Acoustics and Vibration Mechanics Branch of EDF's Research and Development Division is in charge of performing finite element calculations, for the study of the vibratory behaviour of nuclear components. Due to the size and the geometrical complexity of some of these components, EDF has developed sub-structure synthesis methods for modal analysis of large structures. Both Craig-Bampton's and Mac Neal's methods have been implemented in the general mechanics code of EDF: the Aster Code. Craig-Bampton sub-structure synthesis approach was used to study the coupling between blade bending and torsional shaft of a turbine generator set. Four sub-structures were defined to make the calculation: a generator, a low pressure rotor, a high pressure rotor and a blade. The results of the modal calculation, show good agreement with the experimental measurements (error < 1 %). It shows the accuracy of component mode synthesis methods. (author). 6 refs., 7 figs

  11. Numerical analysis of modal tomography for solar multi-conjugate adaptive optics

    International Nuclear Information System (INIS)

    Dong Bing; Ren Deqing; Zhang Xi

    2012-01-01

    Multi-conjugate adaptive optics (MCAO) can considerably extend the corrected field of view with respect to classical adaptive optics, which will benefit solar observation in many aspects. In solar MCAO, the Sun structure is utilized to provide multiple guide stars and a modal tomography approach is adopted to implement three-dimensional wavefront restorations. The principle of modal tomography is briefly reviewed and a numerical simulation model is built with three equivalent turbulent layers and a different number of guide stars. Our simulation results show that at least six guide stars are required for an accurate wavefront reconstruction in the case of three layers, and only three guide stars are needed in the two layer case. Finally, eigenmode analysis results are given to reveal the singular modes that cannot be precisely retrieved in the tomography process.

  12. A retrospective analysis of preoperative staging modalities for oral squamous cell carcinoma.

    Science.gov (United States)

    Kähling, Ch; Langguth, T; Roller, F; Kroll, T; Krombach, G; Knitschke, M; Streckbein, Ph; Howaldt, H P; Wilbrand, J-F

    2016-12-01

    An accurate preoperative assessment of cervical lymph node status is a prerequisite for individually tailored cancer therapies in patients with oral squamous cell carcinoma. The detection of malignant spread and its treatment crucially influence the prognosis. The aim of the present study was to analyze the different staging modalities used among patients with a diagnosis of primary oral squamous cell carcinoma between 2008 and 2015. An analysis of preoperative staging findings, collected by clinical palpation, ultrasound, and computed tomography (CT), was performed. The results obtained were compared with the results of the final histopathological findings of the neck dissection specimens. A statistical analysis using McNemar's test was performed. The sensitivity of CT for the detection of malignant cervical tumor spread was 74.5%. The ultrasound obtained a sensitivity of 60.8%. Both CT and ultrasound demonstrated significantly enhanced sensitivity compared to the clinical palpation with a sensitivity of 37.1%. No significant difference was observed between CT and ultrasound. A combination of different staging modalities increased the sensitivity significantly compared with ultrasound staging alone. No significant difference in sensitivity was found between the combined use of different staging modalities and CT staging alone. The highest sensitivity, of 80.0%, was obtained by a combination of all three staging modalities: clinical palpation, ultrasound and CT. The present study indicates that CT has an essential role in the preoperative staging of patients with oral squamous cell carcinoma. Its use not only significantly increases the sensitivity of cervical lymph node metastasis detection but also offers a preoperative assessment of local tumor spread and resection borders. An additional non-invasive cervical lymph node examination increases the sensitivity of the tumor staging process and reduces the risk of occult metastasis. Copyright © 2016 European

  13. Experimental modal analysis of the steam inlet pipe to the Chooz B1 high pressure turbine

    International Nuclear Information System (INIS)

    Guihot, O.; Anne, J.P.; Chartain, G.; Le Pironnec, D.

    1993-05-01

    This report presents the results of the modal analysis carried out on one of the steam inlet pipe of the high pressure turbine of the Chooz B1 power plant. This experimental analysis is made within the frame of the research and development project ''dynamical, acoustical and aerodynamical behaviour of the turbogenerator N4''. This research program provides amongst others, numerical studies with the software CIRCUS and ASTER, in order to verify the dynamical behaviour of the designed inlet pipe. The numerical models will be updated from results of the experimental modal analysis to improve the numerical representation of this pipe. All the identified modes in the frequency band [5.2000] Hz are presented in the report. The modal characteristics of the main modes are detailed. Further analysis have been made, in order ease the updating of the numerical models. They consisted in an analysis of the evolution of the dynamical behaviour due to a change of the boundary conditions of the inlet valve frame on one hand and resulting from the presence of an additional mass on the pipe, at the level of the middle flange, on the other hand. The analysis made in low frequency range shows that the pipe is thoroughly embedded in the frame of the high pressure turbine. On the other hand, the boundary conditions on the inlet valve frame are more difficult to determine, because the dynamical behaviour of the valve frame and the upper pipe can not be uncoupled from the considered pipe. The main shell modes of ranks 2, 3 and 4 have been very accurately identified. The most relevant modes to update the numerical models are given. (authors). 48 figs., 18 tabs., 4 refs

  14. Enunciative analysis of modals in libras-portuguese simultaneous interpretation's corpus

    Directory of Open Access Journals (Sweden)

    Anderson Almeida-Silva

    2015-12-01

    Full Text Available This paper focuses on the work of the sign Language interpreter in the condition of a second speaker within the speech production. These professionals, when interpreting, they look for re-create [actualize] the emanated concepts from the source language into the target language, creating, then, a second enunciative instance. The theoretical basis is situated in the perspective of the theory of enunciation (BENVENISTE, 1989; FLORES, 2008, 2009a, 2009b, 2010 and in the study of the modals in spoken languages and LIBRAS. We aim to find what are the marks left in the discourse by the second speaker of the text, in this case, the interpreter, regarding specifically to the use of modals, and additionally, to analyze their choices for using one or other type of modal (in the target text, which might have been made explicit or implicit in the first enunciative context (source text. In order to reach these goals, sampling was composed by a transcription of a video-recorded speech of a deaf person with the length of 40’ (forty minutes that was being simultaneously interpreted into spoken Portuguese. Six excerpts from the total speech, in which modal’s occurrences were attested within the source or target language, were submitted to the analysis. The main findings are: 1. the tendency of the deontic modality being almost always interpreted in the same way of the source language; 2. the interpreting choices are always guided by enunciative clues that are left in the speech of the first speaker, to which the interpreters must to demonstrate expertise in recognizing these language-specific aspects; 3. in the absence of explicit modals in the speech, the interpreters appears to be sensible to the modal’s notions spread by the whole text’s surface; 4. the temporal omission of epistemic modals with a high degree of certainty is understood as an interpretative strategy and not as an infidelity with the original information; 5. the term “tempo de

  15. A density distribution algorithm for bone incorporating local orthotropy, modal analysis and theories of cellular solids.

    Science.gov (United States)

    Impelluso, Thomas J

    2003-06-01

    An algorithm for bone remodeling is presented which allows for both a redistribution of density and a continuous change of principal material directions for the orthotropic material properties of bone. It employs a modal analysis to add density for growth and a local effective strain based analysis to redistribute density. General re-distribution functions are presented. The model utilizes theories of cellular solids to relate density and strength. The code predicts the same general density distributions and local orthotropy as observed in reality.

  16. Jet Engine Bird Ingestion Simulations: Comparison of Rotating to Non-Rotating Fan Blades

    Science.gov (United States)

    Howard, Samuel A.; Hammer, Jeremiah T.; Carney, Kelly S.; Pereira, J. Michael

    2013-01-01

    Bird strike events in commercial airliners are a fairly common occurrence. According to data collected by the US Department of Agriculture, over 80,000 bird strikes were reported in the period 1990 to 2007 in the US alone (Ref. 1). As a result, bird ingestion is an important factor in aero engine design and FAA certification. When it comes to bird impacts on engine fan blades, the FAA requires full-scale bird ingestion tests on an engine running at full speed to pass certification requirements. These rotating tests are complex and very expensive. To reduce development costs associated with new materials for fan blades, it is desirable to develop more cost effective testing procedures than full-scale rotating engine tests for material evaluation. An impact test on a nonrotating single blade that captures most of the salient physics of the rotating test would go a long way towards enabling large numbers of evaluative material screening tests. NASA Glenn Research Center has been working to identify a static blade test procedure that would be effective at reproducing similar results as seen in rotating tests. The current effort compares analytical simulations of a bird strike on various non-rotating blades to a bird strike simulation on a rotating blade as a baseline case. Several different concepts for simulating the rotating loads on a non-rotating blade were analyzed with little success in duplicating the deformation results seen in the rotating case. The rotating blade behaves as if it were stiffer than the non-rotating blade resulting in less plastic deformation from a given bird impact. The key factor limiting the success of the non-rotating blade simulations is thought to be the effect of gyroscopics. Prior to this effort, it was anticipated the difficulty would be in matching the prestress in the blade due to centrifugal forces Additional work is needed to verify this assertion, and to determine if a static test procedure can simulate the gyroscopic effects in

  17. Modal Analysis on Fluid-Structure Interaction of MW-Level Vertical Axis Wind Turbine Tower

    Directory of Open Access Journals (Sweden)

    Tan Jiqiu

    2014-05-01

    Full Text Available In order to avoid resonance problem of MW-level vertical axis wind turbine induced by wind, a flow field model of the MW-level vertical axis wind turbine is established by using the fluid flow control equations, calculate flow’s velocity and pressure of the MW-level vertical axis wind turbine and load onto tower’s before and after surface, study the Modal analysis of fluid-structure interaction of MW-level vertical axis wind turbine tower. The results show that fluid-structure interaction field of MW- level vertical axis wind turbine tower has little effect on the modal vibration mode, but has a great effect on its natural frequency and the maximum deformation, and the influence will decrease with increasing of modal order; MW-level vertical axis wind turbine tower needs to be raised the stiffness and strength, its structure also needs to be optimized; In the case of satisfy the intensity, the larger the ratio of the tower height and wind turbines diameter, the more soft the MW-level vertical axis wind turbine tower, the lower its frequency.

  18. Hybrid motion sensing and experimental modal analysis using collocated smartphone camera and accelerometers

    International Nuclear Information System (INIS)

    Ozer, Ekin; Feng, Dongming; Feng, Maria Q

    2017-01-01

    State-of-the-art multisensory technologies and heterogeneous sensor networks propose a wide range of response measurement opportunities for structural health monitoring (SHM). Measuring and fusing different physical quantities in terms of structural vibrations can provide alternative acquisition methods and improve the quality of the modal testing results. In this study, a recently introduced SHM concept, SHM with smartphones, is focused to utilize multisensory smartphone features for a hybridized structural vibration response measurement framework. Based on vibration testing of a small-scale multistory laboratory model, displacement and acceleration responses are monitored using two different smartphone sensors, an embedded camera and accelerometer, respectively. Double-integration or differentiation among different measurement types is performed to combine multisensory measurements on a comparative basis. In addition, distributed sensor signals from collocated devices are processed for modal identification, and performance of smartphone-based sensing platforms are tested under different configuration scenarios and heterogeneity levels. The results of these tests show a novel and successful implementation of a hybrid motion sensing platform through multiple sensor type and device integration. Despite the heterogeneity of motion data obtained from different smartphone devices and technologies, it is shown that multisensory response measurements can be blended for experimental modal analysis. Getting benefit from the accessibility of smartphone technology, similar smartphone-based dynamic testing methodologies can provide innovative SHM solutions with mobile, programmable, and cost-free interfaces. (paper)

  19. Hybrid motion sensing and experimental modal analysis using collocated smartphone camera and accelerometers

    Science.gov (United States)

    Ozer, Ekin; Feng, Dongming; Feng, Maria Q.

    2017-10-01

    State-of-the-art multisensory technologies and heterogeneous sensor networks propose a wide range of response measurement opportunities for structural health monitoring (SHM). Measuring and fusing different physical quantities in terms of structural vibrations can provide alternative acquisition methods and improve the quality of the modal testing results. In this study, a recently introduced SHM concept, SHM with smartphones, is focused to utilize multisensory smartphone features for a hybridized structural vibration response measurement framework. Based on vibration testing of a small-scale multistory laboratory model, displacement and acceleration responses are monitored using two different smartphone sensors, an embedded camera and accelerometer, respectively. Double-integration or differentiation among different measurement types is performed to combine multisensory measurements on a comparative basis. In addition, distributed sensor signals from collocated devices are processed for modal identification, and performance of smartphone-based sensing platforms are tested under different configuration scenarios and heterogeneity levels. The results of these tests show a novel and successful implementation of a hybrid motion sensing platform through multiple sensor type and device integration. Despite the heterogeneity of motion data obtained from different smartphone devices and technologies, it is shown that multisensory response measurements can be blended for experimental modal analysis. Getting benefit from the accessibility of smartphone technology, similar smartphone-based dynamic testing methodologies can provide innovative SHM solutions with mobile, programmable, and cost-free interfaces.

  20. Modal analysis by holographic interferometry of a turbine blade for aircraft engines

    Science.gov (United States)

    Caponero, Michele A.; De Angelis, Alberto; Filetti, V. R.; Gammella, S.

    1994-11-01

    Within the planning stage devoted to realize an innovative turbine for an aircraft engine, an experimental prototype has been made. Several measurements have been carried out to experimentally verify the expected structural and dynamic features of such a prototype. Expected properties were worked out by finite elements method, using the well-known Nastran software package. Natural frequencies and vibration modes of the designed prototype were computed assuming the turbine being in both `dynamic condition' (rotating turbine at running speed and temperature), and in `static condition' (still turbine at room temperature). We present the experimental modal analysis carried out by time average holographic interferometry, being the prototype in `static condition;' results show the modal behavior of the prototype. Experimental and computed modal features are compared to evaluate the reliability of the finite elements model of the turbine used for computation by the Nastran package; reliability of the finite elements model must be checked to validate results computed assuming the turbine blade is in hostile environments, such as `dynamic condition,' which could hardly be tested by experimental measurements. A piezoelectric transducer was used to excite the turbine blade by sine variable pressure. To better estimate the natural vibration modes, two holographic interferograms have been made for each identified natural frequency, being the sensitivity vector directions of the two interferograms perpendicular to each other. The first ten lower natural frequencies and vibration modes of the blade have been analyzed; experimental and computed results are compared and discussed. Experimental and computed values of natural frequencies are in good agrement between each other. Several differences are present between experimental and computed modal patterns; a possible cause of such discrepancies is identified in wrong structural constraints imposed at nodes of the finite elements

  1. Large-scale dynamo of accretion disks around supermassive nonrotating black holes

    Directory of Open Access Journals (Sweden)

    Poplavsky A.L.

    2006-01-01

    Full Text Available In this paper one presents an analytical model of accretion disk magnetosphere dynamics around supermassive nonrotating black holes in the centers of active galactic nuclei. Based on general relativistic equations of magneto hydrodynamics, the nonstationary solutions for time-dependent dynamo action in the accretion disks, spatial and temporal distribution of magnetic field are found. It is shown that there are two distinct stages of dynamo process: the transient and the steady-state regimes, the induction of magnetic field at t > 6:6665 x 1011GM/c3 s becomes stationary, magnetic field is located near the innermost stable circular orbit, and its value rises up to ~ 105 G. Applications of such systems with nonrotating black holes in real active galactic nuclei are discussed.

  2. Statistical analysis of modal parameters of a suspension bridge based on Bayesian spectral density approach and SHM data

    Science.gov (United States)

    Li, Zhijun; Feng, Maria Q.; Luo, Longxi; Feng, Dongming; Xu, Xiuli

    2018-01-01

    Uncertainty of modal parameters estimation appear in structural health monitoring (SHM) practice of civil engineering to quite some significant extent due to environmental influences and modeling errors. Reasonable methodologies are needed for processing the uncertainty. Bayesian inference can provide a promising and feasible identification solution for the purpose of SHM. However, there are relatively few researches on the application of Bayesian spectral method in the modal identification using SHM data sets. To extract modal parameters from large data sets collected by SHM system, the Bayesian spectral density algorithm was applied to address the uncertainty of mode extraction from output-only response of a long-span suspension bridge. The posterior most possible values of modal parameters and their uncertainties were estimated through Bayesian inference. A long-term variation and statistical analysis was performed using the sensor data sets collected from the SHM system of the suspension bridge over a one-year period. The t location-scale distribution was shown to be a better candidate function for frequencies of lower modes. On the other hand, the burr distribution provided the best fitting to the higher modes which are sensitive to the temperature. In addition, wind-induced variation of modal parameters was also investigated. It was observed that both the damping ratios and modal forces increased during the period of typhoon excitations. Meanwhile, the modal damping ratios exhibit significant correlation with the spectral intensities of the corresponding modal forces.

  3. Entropy of nonrotating isolated horizons in Lovelock theory from loop quantum gravity

    Science.gov (United States)

    Wang, Jing-Bo; Huang, Chao-Guang; Li, Lin

    2016-08-01

    In this paper, the BF theory method is applied to the nonrotating isolated horizons in Lovelock theory. The final entropy matches the Wald entropy formula for this theory. We also confirm the conclusion obtained by Bodendorfer et al. that the entropy is related to the flux operator rather than the area operator in general diffeomorphic-invariant theory. Supported by National Natural Science Foundation of China (11275207)

  4. Operational modal analysis on a VAWT in a large wind tunnel using stereo vision technique

    DEFF Research Database (Denmark)

    Najafi, Nadia; Schmidt Paulsen, Uwe

    2017-01-01

    This paper is about development and use of a research based stereo vision system for vibration and operational modal analysis on a parked, 1-kW, 3-bladed vertical axis wind turbine (VAWT), tested in a wind tunnel at high wind. Vibrations were explored experimentally by tracking small deflections...... of the markers on the structure with two cameras, and also numerically, to study structural vibrations in an overall objective to investigate challenges and to prove the capability of using stereo vision. Two high speed cameras provided displacement measurements at no wind speed interference. The displacement...

  5. Modal Analysis on Fluid-Structure Interaction of MW-Level Vertical Axis Wind Turbine Tower

    OpenAIRE

    Tan Jiqiu; Zhong Dingqing; Wang Qiong

    2014-01-01

    In order to avoid resonance problem of MW-level vertical axis wind turbine induced by wind, a flow field model of the MW-level vertical axis wind turbine is established by using the fluid flow control equations, calculate flow’s velocity and pressure of the MW-level vertical axis wind turbine and load onto tower’s before and after surface, study the Modal analysis of fluid-structure interaction of MW-level vertical axis wind turbine tower. The results show that fluid-structure interaction fie...

  6. SELECTIVE MODAL ANALYSIS OF POWER FLOW OSCILLATION IN LARGE SCALE LONGITUDINAL POWER SYSTEMS

    Directory of Open Access Journals (Sweden)

    Wirindi -

    2009-06-01

    Full Text Available Novel selective modal analysis for the determination of low frequency power flow oscillation behaviour based on eigenvalues with corresponding damping ratio, cumulative damping index, and participation factors is proposed. The power system being investigated consists of three large longitudinally interconnected areas with some weak tie lines. Different modes, such as exciter modes, inter area modes, and local modes of the dominant poles are fully studied to find out the significant level of system damping and other factors producing power flow instability. The nature of the energy exchange between area is determined and strategic power flow stability improvement is developed and tested.

  7. Modal and Dynamic Analysis of a Vehicle with Kinetic Dynamic Suspension System

    Directory of Open Access Journals (Sweden)

    Bangji Zhang

    2016-01-01

    Full Text Available A novel kinetic dynamic suspension (KDS system is presented for the cooperative control of the roll and warp motion modes of off-road vehicles. The proposed KDS system consists of two hydraulic cylinders acting on the antiroll bars. Hence, the antiroll bars are not completely replaced by the hydraulic system, but both systems are installed. In this paper, the vibration analysis in terms of natural frequencies of different motion modes in frequency domain for an off-road vehicle equipped with different configurable suspension systems is studied by using the modal analysis method. The dynamic responses of the vehicle with different configurable suspension systems are investigated under different road excitations and maneuvers. The results of the modal and dynamic analysis prove that the KDS system can reduce the roll and articulation motions of the off-road vehicle without adding extra bounce stiffness and deteriorating the ride comfort. Furthermore, the roll stiffness is increased and the warp stiffness is decreased by the KDS system, which could significantly enhance handing performance and off-road capability.

  8. Analysis of enhanced modal damping ratio in porous materials using an acoustic-structure interaction model

    DEFF Research Database (Denmark)

    Kook, Junghwan; Jensen, Jakob Søndergaard

    2014-01-01

    The aim of this paper is to investigate the enhancement of the damping ratio of a structure with embedded microbeam resonators in air-filled internal cavities. In this context, we discuss theoretical aspects in the framework of the effective modal damping ratio (MDR) and derive an approximate...... relation expressing how an increased damping due to the acoustic medium surrounding the microbeam affect the MDR of the macrobeam. We further analyze the effect of including dissipation of the acoustic medium by using finite element (FE) analysis with acoustic-structure interaction (ASI) using a simple...... phenomenological acoustic loss model. An eigenvalue analysis is carried out to demonstrate the improvement of the damping characteristic of the macrobeam with the resonating microbeam in the lossy air and the results are compared to a forced vibration analysis for a macrobeam with one or multiple embedded...

  9. The effect of time synchronization of wireless sensors on the modal analysis of structures

    International Nuclear Information System (INIS)

    Krishnamurthy, V; Sazonov, E; Fowler, K

    2008-01-01

    Driven by the need to reduce the installation cost and maintenance cost of structural health monitoring (SHM) systems, wireless sensor networks (WSNs) are becoming increasingly popular. Perfect time synchronization amongst the wireless sensors is a key factor enabling the use of low-cost, low-power WSNs for structural health monitoring applications based on output-only modal analysis of structures. In this paper we present a theoretical framework for analysis of the impact created by time delays in the measured system response on the reconstruction of mode shapes using the popular frequency domain decomposition (FDD) technique. This methodology directly estimates the change in mode shape values based on sensor synchronicity. We confirm the proposed theoretical model by experimental validation in modal identification experiments performed on an aluminum beam. The experimental validation was performed using a wireless intelligent sensor and actuator network (WISAN) which allows for close time synchronization between sensors (0.6–10 µs in the tested configuration) and guarantees lossless data delivery under normal conditions. The experimental results closely match theoretical predictions and show that even very small delays in output response impact the mode shapes

  10. Seismic Assessment of Buildings: Proposal of a New Modified Uncoupled Modal Response History Analysis

    International Nuclear Information System (INIS)

    Jerez, Sandra; Mebarki, Ahmed

    2010-01-01

    This paper develops a new modified uncoupled modal response history analysis (M-UMRHA) in order to study the seismic behavior of structures. It aims to provide an acceptable accuracy with reduced calculation duration in comparison to complete analysis, i.e. the THA. The proposed method improves the existing UMRHA, developed by Chopra and Goel [1], by considering an energy based approach to build the capacity curve [2] and a pseudo-adaptive feature to account for changes in modal shapes after yielding, motivated by an adaptive method [3]. Validation is made by comparison with NLTHA as well as other simplified methods. Low and medium-rise RC buildings were analyzed under real ground motion records. Results show good estimates of structural parameters and give good correlation between damage and story displacements as well as drifts. Like other simplified methods, accuracy decreases in the inelastic domain. However, this procedure gives acceptable estimates of structural response with a few additional calculations and it has the potential to be used in large scale studies, and probabilistic approaches.

  11. Scaling of mode shapes from operational modal analysis using harmonic forces

    Science.gov (United States)

    Brandt, A.; Berardengo, M.; Manzoni, S.; Cigada, A.

    2017-10-01

    This paper presents a new method for scaling mode shapes obtained by means of operational modal analysis. The method is capable of scaling mode shapes on any structure, also structures with closely coupled modes, and the method can be used in the presence of ambient vibration from traffic or wind loads, etc. Harmonic excitation can be relatively easily accomplished by using general-purpose actuators, also for force levels necessary for driving large structures such as bridges and highrise buildings. The signal processing necessary for mode shape scaling by the proposed method is simple and the method can easily be implemented in most measurement systems capable of generating a sine wave output. The tests necessary to scale the modes are short compared to typical operational modal analysis test time. The proposed method is thus easy to apply and inexpensive relative to some other methods for scaling mode shapes that are available in literature. Although it is not necessary per se, we propose to excite the structure at, or close to, the eigenfrequencies of the modes to be scaled, since this provides better signal-to-noise ratio in the response sensors, thus permitting the use of smaller actuators. An extensive experimental activity on a real structure was carried out and the results reported demonstrate the feasibility and accuracy of the proposed method. Since the method utilizes harmonic excitation for the mode shape scaling, we propose to call the method OMAH.

  12. Acoustic and Perceptual Analysis of Modal and Falsetto Registers in Females with Dysphonia

    Science.gov (United States)

    Li, Nicole Y. K.; Yiu, Edwin M-L.

    2006-01-01

    Modal and falsetto registers are the basic vocal qualities used in female speaking voices. The purpose of this study was to identify the frequency at which modal register changed to falsetto register and the frequency range of each modal and falsetto register produced under three loudness levels: soft, comfortable and loud phonations in normal and…

  13. The modal analysis of a pipe elbow with realistic boundary conditions

    International Nuclear Information System (INIS)

    Carneiro, J.O.; Melo, F.J.Q. de; Rodrigues, J.F.D.; Lopes, H.; Teixeira, V.

    2005-01-01

    A vibration analysis for the determination of the natural frequencies and the associated eigenmodes of a pipe elbow with end-flanges or tangent terminations was performed. A numerical investigation of this problem was achieved with a semi-analytic definition finite ring element and a commercial finite element code. To assess the accuracy of the numerical solution for the elbow vibration, an experimental modal analysis was performed on a curved and on a straight pipe. The responses were processed by a data acquisition system which performs a fast Fourier transform on the time histories to convert them from a time to frequency domain, these leading to the extraction of natural frequencies and mode shapes associated with the test-specimen. The results were compared with the corresponding ones from the numerical approach and discussion about the results completes the paper

  14. Modal analysis of railway bridge hangers using artificial and ambient excitation

    Science.gov (United States)

    Link, M.; Weiland, M.; Yu, F.

    2002-12-01

    This paper describes the methods used and results obtained from analysing some resonance phenomena which were observed on a steel railway bridge. These phenomena were visible on the slender hangers connecting the arch girder and the main truss girder under certain wind conditions. The paper describes the set up of a vibration monitoring system designed to measure the vibration response of the hangers together with the wind velocity and the wind direction over a period of several months under operational conditions. These data should yield the basis for correlating the wind and the structural characteristics. In addition artificial impulse hammer excitation was used to measure the modal characteristics (natural frequencies and modes of the hangers separately. The results of these tests compared well with those obtained from applying some “output only" modal identification techniques to the operational response data with unknown excitation forces. The results also compared well to analytical predictions and were used to identify the axial forces in the hangers by updating the axial force minimising the test/analysis deviations. The results allowed to estimate the fatigue life of the hangers confirming the need for the design of anti- vibration devices.

  15. Prognostic factors and multidisciplinary treatment modalities for brain metastases from colorectal cancer: analysis of 93 patients

    International Nuclear Information System (INIS)

    Gu, Xiao-Dong; Cai, Yan-Tao; Zhou, Yi-Ming; Li, Zhen-Yang; Xiang, Jian-Bin; Chen, Zong-You

    2015-01-01

    The purpose of this study was to review patient characteristics and evaluate the potential factors affecting prognosis in cases of brain metastasis (BM) from colorectal cancer (CRC). We retrospectively reviewed 93 cases of BM from CRC in our hospital. Patient demographics, neurologic symptoms, and location and number of BMs were recorded. Factors analyzed included: age; sex; Karnofsky performance score; number of BMs; presence of extracranial metastases; dimensions; location of tumors; treatment modalities. The overall 1- and 2-year survival rates were 27.7 and 9.9 %. On multivariate analysis, the number of BMs, extracranial metastases and the initial treatment modalities were found to be independent prognostic factors for overall survival. Patients treated with surgical resection followed by WBRT or SRS had an improved prognosis relative to those treated with surgery alone (P = 0.02 and P = 0.02, respectively). No significance difference in survival rate was found between patients treated with SRS alone or SRS plus WBRT (P = 0.11). Surgical resection of BMs from CRC in selected patients may help prolong survival. Additional radiotherapy following surgery is valuable in improving prognosis. Extracranial metastasis, multiple BM lesions and initial non operation can be considered as independent factors associated with poor prognosis

  16. Operational Modal Analysis and the Performance Assessment of Vehicle Suspension Systems

    Directory of Open Access Journals (Sweden)

    L. Soria

    2012-01-01

    Full Text Available Comfort, road holding and safety of passenger cars are mainly influenced by an appropriate design of suspension systems. Improvements of the dynamic behaviour can be achieved by implementing semi-active or active suspension systems. In these cases, the correct design of a well-performing suspension control strategy is of fundamental importance to obtain satisfying results. Operational Modal Analysis allows the experimental structural identification in those that are the real operating conditions: Moving from output-only data, leading to modal models linearised around the more interesting working points and, in the case of controlled systems, providing the needed information for the optimal design and verification of the controller performance. All these characters are needed for the experimental assessment of vehicle suspension systems. In the paper two suspension architectures are considered equipping the same car type. The former is a semi-active commercial system, the latter a novel prototypic active system. For the assessment of suspension performance, two different kinds of tests have been considered, proving ground tests on different road profiles and laboratory four poster rig tests. By OMA-processing the signals acquired in the different testing conditions and by comparing the results, it is shown how this tool can be effectively utilised to verify the operation and the performance of those systems, by only carrying out a simple, cost-effective road test.

  17. SU-E-I-83: Error Analysis of Multi-Modality Image-Based Volumes of Rodent Solid Tumors Using a Preclinical Multi-Modality QA Phantom

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y [University of Kansas Hospital, Kansas City, KS (United States); Fullerton, G; Goins, B [University of Texas Health Science Center at San Antonio, San Antonio, TX (United States)

    2015-06-15

    Purpose: In our previous study a preclinical multi-modality quality assurance (QA) phantom that contains five tumor-simulating test objects with 2, 4, 7, 10 and 14 mm diameters was developed for accurate tumor size measurement by researchers during cancer drug development and testing. This study analyzed the errors during tumor volume measurement from preclinical magnetic resonance (MR), micro-computed tomography (micro- CT) and ultrasound (US) images acquired in a rodent tumor model using the preclinical multi-modality QA phantom. Methods: Using preclinical 7-Tesla MR, US and micro-CT scanners, images were acquired of subcutaneous SCC4 tumor xenografts in nude rats (3–4 rats per group; 5 groups) along with the QA phantom using the same imaging protocols. After tumors were excised, in-air micro-CT imaging was performed to determine reference tumor volume. Volumes measured for the rat tumors and phantom test objects were calculated using formula V = (π/6)*a*b*c where a, b and c are the maximum diameters in three perpendicular dimensions determined by the three imaging modalities. Then linear regression analysis was performed to compare image-based tumor volumes with the reference tumor volume and known test object volume for the rats and the phantom respectively. Results: The slopes of regression lines for in-vivo tumor volumes measured by three imaging modalities were 1.021, 1.101 and 0.862 for MRI, micro-CT and US respectively. For phantom, the slopes were 0.9485, 0.9971 and 0.9734 for MRI, micro-CT and US respectively. Conclusion: For both animal and phantom studies, random and systematic errors were observed. Random errors were observer-dependent and systematic errors were mainly due to selected imaging protocols and/or measurement method. In the animal study, there were additional systematic errors attributed to ellipsoidal assumption for tumor shape. The systematic errors measured using the QA phantom need to be taken into account to reduce measurement

  18. VoxelStats: A MATLAB Package for Multi-Modal Voxel-Wise Brain Image Analysis.

    Science.gov (United States)

    Mathotaarachchi, Sulantha; Wang, Seqian; Shin, Monica; Pascoal, Tharick A; Benedet, Andrea L; Kang, Min Su; Beaudry, Thomas; Fonov, Vladimir S; Gauthier, Serge; Labbe, Aurélie; Rosa-Neto, Pedro

    2016-01-01

    In healthy individuals, behavioral outcomes are highly associated with the variability on brain regional structure or neurochemical phenotypes. Similarly, in the context of neurodegenerative conditions, neuroimaging reveals that cognitive decline is linked to the magnitude of atrophy, neurochemical declines, or concentrations of abnormal protein aggregates across brain regions. However, modeling the effects of multiple regional abnormalities as determinants of cognitive decline at the voxel level remains largely unexplored by multimodal imaging research, given the high computational cost of estimating regression models for every single voxel from various imaging modalities. VoxelStats is a voxel-wise computational framework to overcome these computational limitations and to perform statistical operations on multiple scalar variables and imaging modalities at the voxel level. VoxelStats package has been developed in Matlab(®) and supports imaging formats such as Nifti-1, ANALYZE, and MINC v2. Prebuilt functions in VoxelStats enable the user to perform voxel-wise general and generalized linear models and mixed effect models with multiple volumetric covariates. Importantly, VoxelStats can recognize scalar values or image volumes as response variables and can accommodate volumetric statistical covariates as well as their interaction effects with other variables. Furthermore, this package includes built-in functionality to perform voxel-wise receiver operating characteristic analysis and paired and unpaired group contrast analysis. Validation of VoxelStats was conducted by comparing the linear regression functionality with existing toolboxes such as glim_image and RMINC. The validation results were identical to existing methods and the additional functionality was demonstrated by generating feature case assessments (t-statistics, odds ratio, and true positive rate maps). In summary, VoxelStats expands the current methods for multimodal imaging analysis by allowing the

  19. Modal analysis of a grid-connected direct-drive permanent magnet synchronous generator wind turbine system

    DEFF Research Database (Denmark)

    Tan, Jin; Wang, Xiao Ru; Chen, Zhe

    2013-01-01

    In order to study the stability of a grid-connected direct-drive permanent magnet synchronous generator (PMSG) wind turbine systems, this paper presents the modal analysis of a PMSG wind turbine system. A PMSG model suitable for small signal stability analysis is presented. The modal properties...... of a grid-connected PMSG wind turbine system are studied. Then the comprehensive impacts of the shaft model, shaft parameters, operation points and lengths of the transmission line on the modal characteristic of the system are investigated by the eigenvalue analysis method. Meanwhile, the corresponding...... analysis. It offers a better understanding about the essence of the stability of grid-connected PMSG wind turbine system....

  20. Operational modal analysis of civil engineering structures an introduction and guide for applications

    CERN Document Server

    Rainieri, Carlo

    2014-01-01

    This book covers all aspects of operational modal analysis for civil engineering, from theoretical background to applications, including measurement hardware, software development, and data processing. In particular, this book provides an extensive description and discussion of OMA methods, their classification and relationship, and advantages and drawbacks. The authors cover both the well-established theoretical background of OMA methods and the most recent developments in the field, providing detailed examples to help the reader better understand the concepts and potentialities of the technique. Additional material is provided (data, software) to help practitioners and students become familiar with OMA. Covering a range of different aspects of OMA, always with the application in mind, the practical perspective adopted in this book makes it ideal for a wide range of readers from researchers to field engineers; graduate and undergraduate students; and technicians interested in structural dynamics, system iden...

  1. Evaluation of damping estimates by automated Operational Modal Analysis for offshore wind turbine tower vibrations

    DEFF Research Database (Denmark)

    Bajrić, Anela; Høgsberg, Jan Becker; Rüdinger, Finn

    2018-01-01

    Reliable predictions of the lifetime of offshore wind turbine structures are influenced by the limited knowledge concerning the inherent level of damping during downtime. Error measures and an automated procedure for covariance driven Operational Modal Analysis (OMA) techniques has been proposed....... In order to obtain algorithmic independent answers, three identification techniques are compared: Eigensystem Realization Algorithm (ERA), covariance driven Stochastic Subspace Identification (COV-SSI) and the Enhanced Frequency Domain Decomposition (EFDD). Discrepancies between automated identification...... techniques are discussed and illustrated with respect to signal noise, measurement time, vibration amplitudes and stationarity of the ambient response. The best bias-variance error trade-off of damping estimates is obtained by the COV-SSI. The proposed automated procedure is validated by real vibration...

  2. Modal Analysis of a Steel Radial Gate Exposed to Different Water Levels

    Science.gov (United States)

    Brusewicz, Krzysztof; Sterpejkowicz-Wersocki, Witold; Jankowski, Robert

    2017-06-01

    With the increase in water retention needs and planned river regulation, it might be important to investigate the dynamic resistance of vulnerable elements of hydroelectric power plants, including steelwater locks. The most frequent dynamic loads affecting hydroengineering structures in Poland include vibrations caused by heavy road and railway traffic, piling works and mining tremors. More destructive dynamic loads, including earthquakes, may also occur in our country, although their incidence is relatively low. However, given the unpredictable nature of such events, as well as serious consequences they might cause, the study of the seismic resistance of the steel water gate, as one of the most vulnerable elements of a hydroelectric power plant, seems to be important. In this study, a steel radial gate has been analyzed. As far as water gates are concerned, it is among the most popular solutions because of its relatively small weight, compared to plain gates. A modal analysis of the steel radial gate was conducted with the use of the FEM in the ABAQUS software. All structural members were modelled using shell elements with detailed geometry representing a real structure.Water was modelled as an added mass affecting the structure. Different water levels were used to determine the most vulnerable state of the working steel water gate. The results of the modal analysis allowed us to compare the frequencies and their eigenmodes in response to different loads, which is one of the first steps in researching the dynamic properties of steel water gates and their behaviour during extreme dynamic loads, including earthquakes.

  3. Some aspects of an induced electric dipole moment in rotating and non-rotating frames.

    Science.gov (United States)

    Oliveira, Abinael B; Bakke, Knut

    2017-06-01

    Quantum effects on a neutral particle (atom or molecule) with an induced electric dipole moment are investigated when it is subject to the Kratzer potential and a scalar potential proportional to the radial distance. In addition, this neutral is placed in a region with electric and magnetic fields. This system is analysed in both non-rotating and rotating reference frames. Then, it is shown that bound state solutions to the Schrödinger equation can be achieved and, in the search for polynomial solutions to the radial wave function, a restriction on the values of the cyclotron frequency is analysed in both reference frames.

  4. Experimental strain modal analysis for beam-like structure by using distributed fiber optics and its damage detection

    Science.gov (United States)

    Cheng, Liangliang; Busca, Giorgio; Cigada, Alfredo

    2017-07-01

    Modal analysis is commonly considered as an effective tool to obtain the intrinsic characteristics of structures including natural frequencies, modal damping ratios, and mode shapes, which are significant indicators for monitoring the health status of engineering structures. The complex mode indicator function (CMIF) can be regarded as an effective numerical tool to perform modal analysis. In this paper, experimental strain modal analysis based on the CMIF has been introduced. Moreover, a distributed fiber-optic sensor, as a dense measuring device, has been applied to acquire strain data along a beam surface. Thanks to the dense spatial resolution of the distributed fiber optics, more detailed mode shapes could be obtained. In order to test the effectiveness of the method, a mass lump—considered as a linear damage component—has been attached to the surface of the beam, and damage detection based on strain mode shape has been carried out. The results manifest that strain modal parameters can be estimated effectively by utilizing the CMIF based on the corresponding simulations and experiments. Furthermore, damage detection based on strain mode shapes benefits from the accuracy of strain mode shape recognition and the excellent performance of the distributed fiber optics.

  5. Xenon spatial oscillation in nuclear power reactors:an analytical approach through non linear modal analysis

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2005-01-01

    It was proponed recently to apply an extension of Lyapunov's first method to the non-linear regime, known as non-linear modal analysis (NMA), to the study of space-time problems in nuclear reactor kinetics, nuclear power plant dynamics and nuclear power plant instrumentation and control(1). The present communication shows how to apply NMA to the study of Xenon spatial oscillations in large nuclear reactors. The set of non-linear modal equations derived by J. Lewins(2) for neutron flux, Xenon concentration and Iodine concentration are discussed, and a modified version of these equations is taken as a starting point. Using the methods of singular perturbation theory a slow manifold is constructed in the space of mode amplitudes. This allows the reduction of the original high dimensional dynamics to a low dimensional one. It is shown how the amplitudes of the first mode for neutron flux field, temperature field and concentrations of Xenon and Iodine fields can have a stable steady state value while the corresponding amplitudes of the second mode oscillates in a stable limit cycle. The extrapolated dimensions of the reactor's core are used as bifurcation parameters. Approximate analytical formulae are obtained for the critical values of this parameters( below which the onset of oscillations is produced), for the period and for the amplitudes of the above mentioned oscillations. These results are applied to the discussion of neutron flux and temperature excursions in critical locations of the reactor's core. The results of NMA can be validated from the results obtained applying suitable computer codes, using homogenization theory(3) to link the complex heterogeneous model of the codes with the simplified mathematical model used for NMA

  6. Circular polarization of gravitational waves from non-rotating supernova cores: a new probe into the pre-explosion hydrodynamics

    Science.gov (United States)

    Hayama, Kazuhiro; Kuroda, Takami; Kotake, Kei; Takiwaki, Tomoya

    2018-06-01

    We present an analysis of the circular polarization of gravitational waves (GWs) using results from three-dimensional (3D), general relativistic (GR) core-collapse simulations of a non-rotating 15 M⊙ star. For the signal detection, we perform a coherent network analysis taking into account the four interferometers of LIGO Hanford, LIGO Livingston, VIRGO, and KAGRA. We focus on the Stokes V parameter, which directly characterizes the asymmetry of the GW circular polarization. We find that the amplitude of the GW polarization becomes bigger for our 3D-GR model that exhibits strong activity of the standing accretion shock instability (SASI). Our results suggest that the SASI-induced accretion flows to the proto-neutron star (PNS) lead to a characteristic, low-frequency modulation (100-200 Hz) in both the waveform and the GW circular polarization. By estimating the signal-to-noise ratio of the GW polarization, we demonstrate that the detection horizon of the circular polarization extends by more than a factor of several times farther comparing to that of the GW amplitude. Our results suggest that the GW circular polarization, if detected, could provide a new probe into the pre-explosion hydrodynamics such as the SASI activity and the g-mode oscillation of the PNS.

  7. Circular polarization of gravitational waves from non-rotating supernova cores: a new probe into the pre-explosion hydrodynamics

    Science.gov (United States)

    Hayama, Kazuhiro; Kuroda, Takami; Kotake, Kei; Takiwaki, Tomoya

    2018-04-01

    We present an analysis of the circular polarization of gravitational-waves (GWs) using results from three-dimensional (3D), general relativistic (GR) core-collapse simulations of a non-rotating 15M⊙ star. For the signal detection, we perform a coherent network analysis taking into account the four interferometers of LIGO Hanford, LIGO Livingston, VIRGO, and KAGRA. We focus on the Stokes V parameter, which directly characterizes the asymmetry of the GW circular polarization. We find that the amplitude of the GW polarization becomes bigger for our 3D-GR model that exhibits strong activity of the standing accretion shock instability (SASI). Our results suggest that the SASI-induced accretion flows to the proto-neutron star (PNS) lead to a characteristic, low-frequency modulation (100 ˜ 200 Hz) in both the waveform and the GW circular polarization. By estimating the signal-to-noise ratio of the GW polarization, we demonstrate that the detection horizon of the circular polarization extends by more than a factor of several times farther comparing to that of the GW amplitude. Our results suggest that the GW circular polarization, if detected, could provide a new probe into the pre-explosion hydrodynamics such as the SASI activity and the g-mode oscillation of the PNS.

  8. Numerical Modal Analysis of Vibrations in a Three-Phase Linear Switched Reluctance Actuator

    Directory of Open Access Journals (Sweden)

    José Salvado

    2017-01-01

    Full Text Available This paper addresses the problem of vibrations produced by switched reluctance actuators, focusing on the linear configuration of this type of machines, aiming at its characterization regarding the structural vibrations. The complexity of the mechanical system and the number of parts used put serious restrictions on the effectiveness of analytical approaches. We build the 3D model of the actuator and use finite element method (FEM to find its natural frequencies. The focus is on frequencies within the range up to nearly 1.2 kHz which is considered relevant, based on preliminary simulations and experiments. Spectral analysis results of audio signals from experimental modal excitation are also shown and discussed. The obtained data support the characterization of the linear actuator regarding the excited modes, its vibration frequencies, and mode shapes, with high potential of excitation due to the regular operation regimes of the machine. The results reveal abundant modes and harmonics and the symmetry characteristics of the actuator, showing that the vibration modes can be excited for different configurations of the actuator. The identification of the most critical modes is of great significance for the actuator’s control strategies. This analysis also provides significant information to adopt solutions to reduce the vibrations at the design.

  9. Dynamic Characterization of the Little Belt Suspension Bridge by Operational Modal Analysis

    DEFF Research Database (Denmark)

    Christensen, Silas Sverre; Brandt, Anders; Andersen, Michael Styrk

    2019-01-01

    . It was found that the first vertical bending mode was 0.156 Hz, which is very near the frequency predicted by the original scale model. In total nine modes are reported, with frequencies from 0.156 to 0.808 Hz, and with damping values between 0.38% and 9.74%. This paper also demonstrates and discusses the use......The (new) Little Belt Bridge, opened in 1970, is a Danish suspension bridge with largest span being 600 m, and a total length of 1700 m. During the design and construction phase, detailed analysis of the dynamic properties of the bridge were carried out both by hand calculations and by measurements...... on a scale model. Recently, the bridge was measured using a setup of 45 simultaneous responses, 30 vertical and 15 lateral, distributed over the main span. Operational modal analysis was carried out on the data set, and the first two vertical bending and torsional modes were compared to those of the model...

  10. Finite-element analysis and modal testing of a rotating wind turbine

    Science.gov (United States)

    Carne, T. G.; Lobitz, D. W.; Nord, A. R.; Watson, R. A.

    1982-10-01

    A finite element procedure, which includes geometric stiffening, and centrifugal and Coriolis terms resulting from the use of a rotating coordinate system, was developed to compute the mode shapes and frequencies of rotating structures. Special applications of this capability was made to Darrieus, vertical axis wind turbines. In a parallel development effort, a technique for the modal testing of a rotating vertical axis wind turbine is established to measure modal parameters directly. Results from the predictive and experimental techniques for the modal frequencies and mode shapes are compared over a wide range of rotational speeds.

  11. Finite element analysis and modal testing of a rotating wind turbine

    Science.gov (United States)

    Carne, T. G.; Lobitz, D. W.; Nord, A. R.; Watson, R. A.

    A finite element procedure, which includes geometric stiffening, and centrifugal and Coriolis terms resulting from the use of a rotating coordinate system, has been developed to compute the mode shapes and frequencies of rotating structures. Special application of this capability has been made to Darrieus, vertical axis wind turbines. In a parallel development effort, a technique for the modal testing of a rotating vertical axis wind turbine has been established to measure modal parameters directly. Results from the predictive and experimental techniques for the modal frequencies and mode shapes are compared over a wide range of rotational speeds.

  12. Voltage stability evaluation facing small disturbances by means of the modal analysis technique; Evaluacion de la estabilidad de voltaje ante disturbios pequenos mediante la tecnica de analisis modal

    Energy Technology Data Exchange (ETDEWEB)

    Leon Rodriguez, Daniel

    2000-12-15

    The economic development of the countries has taken implicit a growing industrialization the one which, joined to those every time bigger resident's necessities, it has caused a constant and progressive increment in the electric power demand. However, in the last years the growth of the electric network of these systems has been more and more limited for diverse such factors as the ecology and the economy, as well as for the social and political costs that implies each new construction in the system. With the presence of these restrictions the electric systems in many cases, have been forced to satisfy the increments in the demand making a more exhaustive use of the infrastructure that they have available and the incorporation of only a few new system elements or constructions. These aspects have caused such systems to operate with more limited security margins and that their stability has to be analyzed in a reliable and precise way. Taking into account the previously mentioned aspects, as the electric systems have had the necessity of operating under forced conditions to satisfy the load demand, voltage stability problems have been presented with more frequency causing serious disturbances and in some cases, total blackouts. With these problems, the voltage stability analysis has taken bigger importance in the studies that the electric utilities carry out. This issue has caused that bigger resources are dedicated for the investigation of this phenomenon with the purpose of understanding and developing tools that allow studying it in a more complete and more truthful way. Modal analysis is one of the most recent and popular steady techniques the one that, from its appearance has had a great peak due to the valuable and quick information that provides, besides its implementation easiness and the little effort computational that it requires. In this work is carried out the voltage stability evaluation of a real electric system applying in a combined way the

  13. Examination of Successful Modal Analysis Techniques Used for Bladed-Disk Assemblies

    National Research Council Canada - National Science Library

    Orsagh, R

    2002-01-01

    Modal testing of bladed-disk assemblies in turbomachines is used to identify the critical natural frequencies and mode shape information used for avoiding the per-rev resonant conditions that cause high cycle fatigue (HCF...

  14. Determination of Stress Histories in Structures by Natural Input Modal Analysis

    DEFF Research Database (Denmark)

    Hjelm, Henrik P.; Brincker, Rune; Graugaard-Jensen, Jesper

    2005-01-01

    In this paper it is shown that stress histories can be estimated with high accuracy by integrating measured accelerations to obtain displacement and then performing a modal decomposition of the so estimated displacements. The relation between the modal coordinate and the stress in an arbitrary....... It is shown that the so estimated stress histories can replace strain gauge measurements in many cases, and it allows for an accurate estimation of fatigue damage....

  15. Multi-Modality Medical Image Fusion Based on Wavelet Analysis and Quality Evaluation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Multi-modality medical image fusion has more and more important applications in medical image analysisand understanding. In this paper, we develop and apply a multi-resolution method based on wavelet pyramid to fusemedical images from different modalities such as PET-MRI and CT-MRI. In particular, we evaluate the different fusionresults when applying different selection rules and obtain optimum combination of fusion parameters.

  16. Real-Time Estimation for Cutting Tool Wear Based on Modal Analysis of Monitored Signals

    Directory of Open Access Journals (Sweden)

    Yongjiao Chi

    2018-05-01

    Full Text Available There is a growing body of literature that recognizes the importance of product safety and the quality problems during processing. The working status of cutting tools may lead to project delay and cost overrun if broken down accidentally, and tool wear is crucial to processing precision in mechanical manufacturing, therefore, this study contributes to this growing area of research by monitoring condition and estimating wear. In this research, an effective method for tool wear estimation was constructed, in which, the signal features of machining process were extracted by ensemble empirical mode decomposition (EEMD and were used to estimate the tool wear. Based on signal analysis, vibration signals that had better linear relationship with tool wearing process were decomposed, then the intrinsic mode functions (IMFs, frequency spectrums of IMFs and the features relating to amplitude changes of frequency spectrum were obtained. The trend that tool wear changes with the features was fitted by Gaussian fitting function to estimate the tool wear. Experimental investigation was used to verify the effectiveness of this method and the results illustrated the correlation between tool wear and the modal features of monitored signals.

  17. MODAL ANALYSIS FOR REVISION OF A FEM MODEL OF A STEEL TRUSS BEAM

    Directory of Open Access Journals (Sweden)

    Michal Venglar

    2017-11-01

    Full Text Available The paper deals with a preparation of a complex FEM model for a local damage detection. The initial verified and validated three-dimensional FEM model of a steel truss bridge in laboratory is revised step-by-step to achieve the accurate model according to the experimental model. The emphasis is on modelling of the joints with 4 rivets and modelling of correct boundary conditions, as well as mass parameters and cross-section dimensions.A modal analysis of the structure is performed in FEM software. Many experimental measurements were made to correctly revise the FEM model. The calculated natural frequencies are compared with the measured ones. In addition, mode-shapes from the calculation are validated with the measured mode-shapes. The difference between the prepared FEM model and the measured specimen is small enough after a few steps of tuning. The verified, validated and revised numerical model can be used in future for a local damage detection.

  18. Modal analysis of graphene-based structures for large deformations, contact and material nonlinearities

    Science.gov (United States)

    Ghaffari, Reza; Sauer, Roger A.

    2018-06-01

    The nonlinear frequencies of pre-stressed graphene-based structures, such as flat graphene sheets and carbon nanotubes, are calculated. These structures are modeled with a nonlinear hyperelastic shell model. The model is calibrated with quantum mechanics data and is valid for high strains. Analytical solutions of the natural frequencies of various plates are obtained for the Canham bending model by assuming infinitesimal strains. These solutions are used for the verification of the numerical results. The performance of the model is illustrated by means of several examples. Modal analysis is performed for square plates under pure dilatation or uniaxial stretch, circular plates under pure dilatation or under the effects of an adhesive substrate, and carbon nanotubes under uniaxial compression or stretch. The adhesive substrate is modeled with van der Waals interaction (based on the Lennard-Jones potential) and a coarse grained contact model. It is shown that the analytical natural frequencies underestimate the real ones, and this should be considered in the design of devices based on graphene structures.

  19. Steel bridges structural health monitoring based on operational modal analysis accommodating evaluation of uncertainty

    Directory of Open Access Journals (Sweden)

    Saeid Jahan

    2017-11-01

    Full Text Available Structural damage detection is based on that the dynamic response of structure will change because of damage. Hence, it is possible to estimate the location and severity of damage leads to changes in the dynamic response before and after the damage. In this study, the genetic fuzzy system has been used for bridge structural health monitoring. A key objective of using genetic algorithms is to automate the design of fuzzy systems. This method is used for damage detection of a single span railway bridge with steel girders and a concrete bridge. For studying damage detection, the numerical models of these two bridges are built with the measured dynamic characteristics. A three-dimensional finite element model and a single two-dimensional girders model of the bridge have been constructed to study usefulness of the genetic fuzzy system for damage detection and the effectiveness of modeling. After analysis to control the uncertainties, the measured frequencies are contaminated with some noise and the effect of that on the achievement of damage detection method is evaluated. The present study has shown that the natural frequency has appropriate sensitivity to different damage scenarios in the structure. In addition, the natural frequency in comparison with other modal parameters, is less affected by random noise. Increasing the number of measurement modes and using torsional modes, will lead to an accurate damage diagnosis even in symmetrical structures.

  20. Modal Analysis of a Simply Supported Steel Beam with Cracks under Temperature Load

    Directory of Open Access Journals (Sweden)

    Yijiang Ma

    2017-01-01

    Full Text Available Based on the transfer matrix method, an analytical method is proposed to conduct the modal analysis of the simply supported steel beam with multiple transverse open cracks under different temperatures. The open cracks are replaced with torsion springs without mass, and local flexibility caused by each crack can be derived; the temperature module is introduced by the mechanical properties variation of the structural material, and the temperature load is caused by the temperature variation, which can be transformed to the axial force on the cross-section. The transfer matrix of the whole beam with the temperature and geometric parameters of cracks can be obtained. According to boundary conditions of the simply supported beam, natural frequencies of the beam can be calculated, which are compared with the finite element results. Results indicate that the analytical method proposed has a high accuracy; the natural frequencies of the simply supported steel beam are mostly affected by the temperature load, which cannot be ignored.

  1. Experimental Modal Analysis on a Rotating Fan Using Tracking-CSLDV

    International Nuclear Information System (INIS)

    Gasparoni, Andrea; Castellini, Paolo; Tomasini, Enrico P.; Allen, Matthew S.; Yang Shifei; Sracic, Michael W.

    2010-01-01

    Continuous Scan Laser Doppler Vibrometry (CSLDV) modifies the traditional mode of operation of a vibrometer by sweeping the laser measurement point continuously over the structure while measuring, enabling one to measure spatially detailed mode shapes quickly and minimizing the inconsistencies that can arise if the structure or test conditions change with time. When a periodic scan path is employed, one can decompose the measurement into the response that would have been measured at each point traversed by the laser and obtain the structure's mode shapes and natural frequencies using conventional modal analysis software. In this paper, continuous-scan vibrometry is performed on a rotating fan, using computer controlled mirrors to track the rotating fan blades while simultaneously sweeping the measurement point over the blades. This has the potential to circumvent the difficulty of attaching contact sensors such as strain gauges, which might modify the structure and invalidate the results. In this work, impact excitation was used to excite a 3-blade fan rotating at various speeds, and the blades were scanned with a cloverleaf pattern that captured the bending of all three blades simultaneously. Some specialized signal processing is helpful in minimizing the effect of rotation frequency harmonics in the measurements, and specific scan strategies are needed to avoid those frequencies, both of these issues are discussed in the paper. While noise in the laser vibrometer does pose some difficulty, the results show that several modes could be extracted and that the tracking-CSLDV results agree with measurements obtained from the parked fan.

  2. Predicting wind-induced vibrations of high-rise buildings using unsteady CFD and modal analysis

    KAUST Repository

    Zhang, Yue

    2015-01-01

    This paper investigates the wind-induced vibration of the CAARC standard tall building model, via unsteady Computational Fluid Dynamics (CFD) and a structural modal analysis. In this numerical procedure, the natural unsteady wind in the atmospheric boundary layer is modeled with an artificial inflow turbulence generation method. Then, the turbulent flow is simulated by the second mode of a Zonal Detached-Eddy Simulation, and a conservative quadrature-projection scheme is adopted to transfer unsteady loads from fluid to structural nodes. The aerodynamic damping that represents the fluid-structure interaction mechanism is determined by empirical functions extracted from wind tunnel experiments. Eventually, the flow solutions and the structural responses in terms of mean and root mean square quantities are compared with experimental measurements, over a wide range of reduced velocities. The significance of turbulent inflow conditions and aeroelastic effects is highlighted. The current methodology provides predictions of good accuracy and can be considered as a preliminary design tool to evaluate the unsteady wind effects on tall buildings.

  3. Dynamic stall characterization using modal analysis of phase-averaged pressure distributions

    Science.gov (United States)

    Harms, Tanner; Nikoueeyan, Pourya; Naughton, Jonathan

    2017-11-01

    Dynamic stall characterization by means of surface pressure measurements can simplify the time and cost associated with experimental investigation of unsteady airfoil aerodynamics. A unique test capability has been developed at University of Wyoming over the past few years that allows for time and cost efficient measurement of dynamic stall. A variety of rotorcraft and wind turbine airfoils have been tested under a variety of pitch oscillation conditions resulting in a range of dynamic stall behavior. Formation, development and separation of different flow structures are responsible for the complex aerodynamic loading behavior experienced during dynamic stall. These structures have unique signatures on the pressure distribution over the airfoil. This work investigates the statistical behavior of phase-averaged pressure distribution for different types of dynamic stall by means of modal analysis. The use of different modes to identify specific flow structures is being investigated. The use of these modes for different types of dynamic stall can provide a new approach for understanding and categorizing these flows. This work uses airfoil data acquired under Army contract W911W60160C-0021, DOE Grant DE-SC0001261, and a gift from BP Alternative Energy North America, Inc.

  4. Modal analysis of the thermal conductivity of nanowires: examining unique thermal transport features

    Science.gov (United States)

    Samaraweera, Nalaka; Larkin, Jason M.; Chan, Kin L.; Mithraratne, Kumar

    2018-06-01

    In this study, unique thermal transport features of nanowires over bulk materials are investigated using a combined analysis based on lattice dynamics and equilibrium molecular dynamics (EMD). The evaluation of the thermal conductivity (TC) of Lenard–Jones nanowires becomes feasible due to the multi-step normal mode decomposition (NMD) procedure implemented in the study. A convergence issue of the TC of nanowires is addressed by the NMD implementation for two case studies, which employ pristine nanowires (PNW) and superlattice nanowires. Interestingly, mode relaxation times at low frequencies of acoustic branches exhibit signs of approaching constant values, thus indicating the convergence of TC. The TC evaluation procedure is further verified by implementing EMD-based Green–Kubo analysis, which is based on a fundamentally different physical perspective. Having verified the NMD procedure, the non-monotonic trend of the TC of nanowires is addressed. It is shown that the principal cause for the observed trend is due to the competing effects of long wavelength phonons and phonon–surface scatterings as the nanowire’s cross-sectional width is changed. A computational procedure is developed to decompose the different modal contribution to the TC of shell alloy nanowires (SANWs) using virtual crystal NMD and the Allen–Feldman theory. Several important conclusions can be drawn from the results. A propagons to non-propagons boundary appeared, resulting in a cut-off frequency (ω cut); moreover, as alloy atomic mass is increased, ω cut shifts to lower frequencies. The existence of non-propagons partly causes the low TC of SANWs. It can be seen that modes with low frequencies demonstrate a similar behavior to corresponding modes of PNWs. Moreover, lower group velocities associated with higher alloy atomic mass resulted in a lower TC of SANWs.

  5. CoSMoMVPA: multi-modal multivariate pattern analysis of neuroimaging datain Matlab / GNU Octave

    Directory of Open Access Journals (Sweden)

    Nikolaas N Oosterhof

    2016-07-01

    Full Text Available Recent years have seen an increase in the popularity of multivariate pattern (MVP analysis of functional magnetic resonance (fMRI data, and, to a much lesser extent, magneto- and electro-encephalography (M/EEG data. We present CoSMoMVPA, a lightweight MVPA (MVP analysis toolbox implemented in the intersection of the Matlab and GNU Octave languages, that treats both fMRI and M/EEG data as first-class citizens.CoSMoMVPA supports all state-of-the-art MVP analysis techniques, including searchlight analyses, classification, correlations, representational similarity analysis, and the time generalization method. These can be used to address both data-driven and hypothesis-driven questions about neural organization and representations, both within and across: space, time, frequency bands, neuroimaging modalities, individuals, and species.It uses a uniform data representation of fMRI data in the volume or on the surface, and of M/EEG data at the sensor and source level. Through various external toolboxes, it directly supports reading and writing a variety of fMRI and M/EEG neuroimaging formats, and, where applicable, can convert between them. As a result, it can be integrated readily in existing pipelines and used with existing preprocessed datasets. CoSMoMVPA overloads the traditional volumetric searchlight concept to support neighborhoods for M/EEG and surface-based fMRI data, which supports localization of multivariate effects of interest across space, time, and frequency dimensions. CoSMoMVPA also provides a generalized approach to multiple comparison correction across these dimensions using Threshold-Free Cluster Enhancement with state-of-the-art clustering and permutation techniques.CoSMoMVPA is highly modular and uses abstractions to provide a uniform interface for a variety of MVP measures. Typical analyses require a few lines of code, making it accessible to beginner users. At the same time, expert programmers can easily extend its functionality

  6. Proceedings of the 1st International Operational Modal Analysis Conference, April 26-27, 2005, Copenhagen, Denmark

    DEFF Research Database (Denmark)

    These proceedings contain approximately 100 papers presented at the 1st International Operational Modal Conference, Copenhagen, Denmark, April 26 - 27, 2005. The conference is jointly organised by Structural Vibration Systems (SVS), Aalborg, Brüel & Kjær Sound and Vibration Measurement A/S and th......These proceedings contain approximately 100 papers presented at the 1st International Operational Modal Conference, Copenhagen, Denmark, April 26 - 27, 2005. The conference is jointly organised by Structural Vibration Systems (SVS), Aalborg, Brüel & Kjær Sound and Vibration Measurement A....../S and the Department of Building Technology and Structural Engineering at Aalborg University. It is the first conference ever to focus solely on experimental modal analysis for cases where only the responses are measured. It was decided to hold the conference to generate interest in operational modal analysis (also...... effort and higher versatility. However, because the mathematical background was initially weak, computer power was insufficient and the equipment not sensitive enough for this kind of testing, the technology has only become popular during the last 3 - 4 years. For this reason, the first conference...

  7. Experimental modal analysis of fractal-inspired multi-frequency structures for piezoelectric energy converters

    International Nuclear Information System (INIS)

    Castagnetti, D

    2012-01-01

    An important issue in the field of energy harvesting through piezoelectric materials is the design of simple and efficient structures which are multi-frequency in the ambient vibration range. This paper deals with the experimental assessment of four fractal-inspired multi-frequency structures for piezoelectric energy harvesting. These structures, thin plates of square shape, were proposed in a previous work by the author and their modal response numerically analysed. The present work has two aims. First, to assess the modal response of these structures through an experimental investigation. Second, to evaluate, through computational simulation, the performance of a piezoelectric converter relying on one of these fractal-inspired structures. The four fractal-inspired structures are examined in the range between 0 and 100 Hz, with regard to both eigenfrequencies and eigenmodes. In the same frequency range, the modal response and power output of the piezoelectric converter are investigated. (paper)

  8. Development and application of an efficient method for performing modal analysis of steam generator tubes in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, Huinam [Dept of Mechanical and Aerospace Engineering, Sunchon National University, Sunchon, 540-742 (Korea, Republic of); Boo, Myung-Hwan [Korea Hydro and Nuclear Power Company, Yuseong-Gu, Daejeon 305-343 (Korea, Republic of); Park, Chi-Yong [KEPCO Research Institute, Yuseong-Gu, Daejeon 305-380 (Korea, Republic of); Ryu, Ki-Wahn, E-mail: kwryu@chonbuk.ac.k [Department of Aerospace Engineering, Chonbuk National University, 664-14, Deogjin-Dong, Jeonju 561-756 (Korea, Republic of)

    2010-10-15

    A typical pressurized water reactor (PWR) steam generator has approximately 10,000 tubes. These tubes have different geometries, supporting conditions, and different material properties due to the non-uniform temperature distribution throughout the steam generator. Even though some tubes may have the same geometry and boundary conditions, the non-uniform distribution of coolant densities adjacent to the tubes causes them to have different added mass effects and dynamic characteristics. Therefore, for a reliable design of the steam generator, a separate modal analysis for each tube is necessary to perform the FIV (flow-induced vibration) analysis. However, the modal analysis of a tube including the finite element modeling is cumbersome and takes lots of time. And when a commercial finite element code is used, interfacing the modal analysis result, such as natural frequencies and mode shapes, with the FIV analysis procedure requires an additional significant amount of time and can possibly incur inadvertent error due to the complexity of data processing. It is therefore impossible to perform the complete FIV analysis for ten thousands of tubes when designing or maintaining a steam generator although it is necessary. Rather, to verify the safe design against the FIV, only a couple of tubes are chosen based on engineering judgment or past experience. In this paper, a computer program, PIAT-MODE, was developed which is able to perform modal analysis of all tubes of a PWR steam generator in a very efficient way. The geometries and boundary conditions of every tube were incorporated into PIAT-MODE using appropriate mathematical formulae. Material property data including the added mass effect was also included in the program. Once a specific tube is selected, the program automatically constructs the finite element model and generates the modal data very quickly. Therefore, modal analysis can be performed for every single tube in a straight way. When PIAT-MODE is coupled

  9. Operational modal analysis on a VAWT in a large wind tunnel using stereo vision technique

    International Nuclear Information System (INIS)

    Najafi, Nadia; Paulsen, Uwe Schmidt

    2017-01-01

    This paper is about development and use of a research based stereo vision system for vibration and operational modal analysis on a parked, 1-kW, 3-bladed vertical axis wind turbine (VAWT), tested in a wind tunnel at high wind. Vibrations were explored experimentally by tracking small deflections of the markers on the structure with two cameras, and also numerically, to study structural vibrations in an overall objective to investigate challenges and to prove the capability of using stereo vision. Two high speed cameras provided displacement measurements at no wind speed interference. The displacement time series were obtained using a robust image processing algorithm and analyzed with data-driven stochastic subspace identification (DD-SSI) method. In addition of exploring structural behaviour, the VAWT testing gave us the possibility to study aerodynamic effects at Reynolds number of approximately 2 × 10"5. VAWT dynamics were simulated using HAWC2. The stereo vision results and HAWC2 simulations agree within 4% except for mode 3 and 4. The high aerodynamic damping of one of the blades, in flatwise motion, would explain the gap between those two modes from simulation and stereo vision. A set of conventional sensors, such as accelerometers and strain gauges, are also measuring rotor vibration during the experiment. The spectral analysis of the output signals of the conventional sensors agrees the stereo vision results within 4% except for mode 4 which is due to the inaccuracy of spectral analysis in picking very closely spaced modes. Finally, the uncertainty of the 3D displacement measurement was evaluated by applying a generalized method based on the law of error propagation, for a linear camera model of the stereo vision system. - Highlights: • The stereo vision technique is used to track deflections on a VAWT in the wind tunnel. • OMA is applied on displacement time series to study the dynamic behaviour of the VAWT. • Stereo vision results enabled us to

  10. MODAL ANALYSIS OF CARRIER SYSTEM FOR HEAVY HORIZONTAL MULTIFUNCTION MACHINING CENTER BY FINITE ELEMENT METHOD

    Directory of Open Access Journals (Sweden)

    Yu. V. Vasilevich

    2014-01-01

    Full Text Available The aim of the paper is to reveal and analyze resonance modes of a large-scale milling-drilling-boring machine. The machine has a movable column with vertical slot occupied by a symmetrical carriage with horizontal ram. Static rigidity of the machine is relatively low due to its large dimensions. So it is necessary to assess possible vibration activity. Virtual and operational trials of the machine have been carried out simultaneously. Modeling has been executed with the help of a finite element method (FEM. The FEM-model takes into account not only rigidity of machine structures but also flexibility of bearings, feed drive systems and guides. Modal FEM-analysis has revealed eight resonance modes that embrace the whole machine tool. They form a frequency interval from 12 to 75 Hz which is undesirable for machining. Three closely located resonances (31-37 Hz are considered as the most dangerous ones. They represent various combinations of three simple motions: vertical oscillations of a carriage, horizontal vibrations of a ram and column torsion. Reliability of FEM- estimations has been proved by in-situ vibration measurements.An effect for stabilization of resonance modes has been detected while making variations in design parameters of the machine tool. For example, a virtual replacement of cast iron for steel in machine structures practically does not have any effect on resonance frequencies. Rigidity increase in some parts (e.g. a ram has also a small effect on a resonance pattern. On the other hand, resonance stability makes it possible to avoid them while selecting a spindle rotation frequency.It is recommended to set double feed drives for all axes. A pair of vertical screws prevents a “pecking” resonance of the carriage at frequency of 54 Hz. It is necessary to foresee an operation of a main drive of such heavy machine tool in the above resonance interval with the spindle frequency of more than 75 Hz. For this purpose it is necessary

  11. A modal method for transient thermal analysis of CANDU fuel channel

    International Nuclear Information System (INIS)

    Park, J-W.; Muzumdar, A.J.

    1996-01-01

    The classical modal expansion technique has been applied to predict transient fuel and coolant temperatures under on-power conditions in a CANDU fuel channel. The temperature profile across the fuel pellet is assumed to be parabolic and fuel and coolant temperatures are expanded with Fourier series. The coefficient derivatives are written in state space form and solved by the Runge-Kutta method of fifth order. To validate the present model, the calculated fuel temperatures for several sample cases were compared with HOTSPOT-II, which employs a more rigorous finite-difference model. The agreement was found to be reasonable for the operational transients simulated. The advantage of the modal method is the fast computation speed for application to the real-time system such as the CANDU simulator which is being currently developed at the Institute for Advanced Engineering (IAE). (author)

  12. Validating a Finite Element Model of a Structure Subjected to Mine Blast with Experimental Modal Analysis

    Science.gov (United States)

    2017-11-01

    Howle, Dmitriy Krayterman, Justin E Pritchett, and Ryan Sorenson 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING...The Under-body Blast Methodology (UBM) for the Test and Evaluation (T&E) program was established to provide a capability for the US Army Test and...and must be validated. The UBM for the T&E program has completed efforts to validate soil models but not structural dynamics models. Modal testing

  13. Mathematical foundation of the application of modal analysis to the investigation of space-time reactor behaviour

    International Nuclear Information System (INIS)

    Obradovic, D.M.

    1970-01-01

    In recent years investigations in the field of kinetics and dynamics of nuclear reactors have been directed towards overcoming an insufficiently accurate point reactor model. For that purpose different mathematical approaches have been used. This thesis is devoted to modal analysis because, from the practical point of view, it is a very promising and, from the mathematical and physical point of view, a very interesting method. Some fundamental mathematical problems connected with the application of modal analysis to the investigations of the reactor space-time behaviour are still unsolved and accordingly our purpose is to solve some of these problems. The spectral properties of the diffusion and P 1 operators are studied in some detail applying the Krein-Rutman theory of the K-positive operators, the Krasnosel'skii theory of u 0 operators, and the Keldis theory of the operator families. The formal solution to the initial value problem (as an abstract Cauchy problem), associated with the diffusion and P 1 operators is also studied. Modal analysis is identified as a set of methods in the mathematical literature known as the Galerkin methods (or projection methods). Following this idea (using the results of the mathematical investigations of the Galerkin methods) and using our results of the investigations of the properties of the diffusion and P 1 operators, the applicability of modal analysis to the approximate solution of the diffusion and P 1 equations and of the eigenvalue problems associated with the diffusion and P 1 operators is established. As an example of the application of modal analysis the Bubnov and Galerkin method is applied to a multiregion thermal nuclear reactor for the determination of: (i) frequency response, (ii) eigenvalues and eigenvectors of the stationary diffusion operator, (iii) eigenvalues and eigenvectors of the non-stationary diffusion operators. On the basis of the expressions obtained the corresponding computer programmes for radial

  14. Continuous wavelet transform analysis and modal location analysis acoustic emission source location for nuclear piping crack growth monitoring

    International Nuclear Information System (INIS)

    Shukri Mohd

    2013-01-01

    Full-text: Source location is an important feature of acoustic emission (AE) damage monitoring in nuclear piping. The ability to accurately locate sources can assist in source characterisation and early warning of failure. This paper describe the development of a novelAE source location technique termed Wavelet Transform analysis and Modal Location (WTML) based on Lamb wave theory and time-frequency analysis that can be used for global monitoring of plate like steel structures. Source location was performed on a steel pipe of 1500 mm long and 220 mm outer diameter with nominal thickness of 5 mm under a planar location test setup using H-N sources. The accuracy of the new technique was compared with other AE source location methods such as the time of arrival (TOA) technique and DeltaTlocation. The results of the study show that the WTML method produces more accurate location results compared with TOA and triple point filtering location methods. The accuracy of the WTML approach is comparable with the deltaT location method but requires no initial acoustic calibration of the structure. (author)

  15. Continuous wavelet transform analysis and modal location analysis acoustic emission source location for nuclear piping crack growth monitoring

    International Nuclear Information System (INIS)

    Mohd, Shukri; Holford, Karen M.; Pullin, Rhys

    2014-01-01

    Source location is an important feature of acoustic emission (AE) damage monitoring in nuclear piping. The ability to accurately locate sources can assist in source characterisation and early warning of failure. This paper describe the development of a novelAE source location technique termed 'Wavelet Transform analysis and Modal Location (WTML)' based on Lamb wave theory and time-frequency analysis that can be used for global monitoring of plate like steel structures. Source location was performed on a steel pipe of 1500 mm long and 220 mm outer diameter with nominal thickness of 5 mm under a planar location test setup using H-N sources. The accuracy of the new technique was compared with other AE source location methods such as the time of arrival (TOA) techniqueand DeltaTlocation. Theresults of the study show that the WTML method produces more accurate location resultscompared with TOA and triple point filtering location methods. The accuracy of the WTML approach is comparable with the deltaT location method but requires no initial acoustic calibration of the structure

  16. Continuous wavelet transform analysis and modal location analysis acoustic emission source location for nuclear piping crack growth monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Mohd, Shukri [Nondestructive Testing Group, Industrial Technology Division, Malaysian Nuclear Agency, 43000, Bangi, Selangor (Malaysia); Holford, Karen M.; Pullin, Rhys [Cardiff School of Engineering, Cardiff University, Queen' s Buildings, The Parade, CARDIFF CF24 3AA (United Kingdom)

    2014-02-12

    Source location is an important feature of acoustic emission (AE) damage monitoring in nuclear piping. The ability to accurately locate sources can assist in source characterisation and early warning of failure. This paper describe the development of a novelAE source location technique termed 'Wavelet Transform analysis and Modal Location (WTML)' based on Lamb wave theory and time-frequency analysis that can be used for global monitoring of plate like steel structures. Source location was performed on a steel pipe of 1500 mm long and 220 mm outer diameter with nominal thickness of 5 mm under a planar location test setup using H-N sources. The accuracy of the new technique was compared with other AE source location methods such as the time of arrival (TOA) techniqueand DeltaTlocation. Theresults of the study show that the WTML method produces more accurate location resultscompared with TOA and triple point filtering location methods. The accuracy of the WTML approach is comparable with the deltaT location method but requires no initial acoustic calibration of the structure.

  17. Modal analysis of main steam line piping under high energy line break condition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae-Jin; Kim, Seung Hyun; Je, Sang-Yun; Chang, Yoon-Suk [Kyung Hee University, Yongin (Korea, Republic of)

    2016-10-15

    If HELB (High Energy Line Break) occurs in NPPs (Nuclear Power Plants), not only environmental effect like release of radioactive material but also secondary structural defects should be considered. Jet impingement phenomenon caused by sudden pipe rupture may lead to severe damage on neighboring safe-related components and other structure. Lots of studies have been conducted to assess dynamic behaviors of the SG and MSL piping while pipe whip restraints and jet impingement shields are taken into account during design stage. Arroyo et al. performed modal analyses of a simple square component to examine the jet impingement phenomenon. Also, structural characteristics were predicted to assure structural integrity against the HELB. In this study, we examined dynamic characteristics of SG and MSL piping in a typical 1000MWe NPP. Simulation was performed by using two commercial computational softwares. In particular, modal analyses were conducted to determine mode shapes and natural frequencies of the structure and maximum displacements. The data obtain from each software were compared and observation was discussed in relation to the jet impingement phenomenon. In this research, modal analyses on the SG and MSL piping were carried out to get natural frequencies, vibration mode shapes and maximum displacements. Thereby, the following key finding was observed. (1) Maximum displacement was calculated at the top of SG outlet nozzle with y-directional bending at the third mode. (2) The differences between two models were respectively 7% in natural frequencies and less than 1% in maximum displacements.

  18. Statistically generated weighted curve fit of residual functions for modal analysis of structures

    Science.gov (United States)

    Bookout, P. S.

    1995-01-01

    A statistically generated weighting function for a second-order polynomial curve fit of residual functions has been developed. The residual flexibility test method, from which a residual function is generated, is a procedure for modal testing large structures in an external constraint-free environment to measure the effects of higher order modes and interface stiffness. This test method is applicable to structures with distinct degree-of-freedom interfaces to other system components. A theoretical residual function in the displacement/force domain has the characteristics of a relatively flat line in the lower frequencies and a slight upward curvature in the higher frequency range. In the test residual function, the above-mentioned characteristics can be seen in the data, but due to the present limitations in the modal parameter evaluation (natural frequencies and mode shapes) of test data, the residual function has regions of ragged data. A second order polynomial curve fit is required to obtain the residual flexibility term. A weighting function of the data is generated by examining the variances between neighboring data points. From a weighted second-order polynomial curve fit, an accurate residual flexibility value can be obtained. The residual flexibility value and free-free modes from testing are used to improve a mathematical model of the structure. The residual flexibility modal test method is applied to a straight beam with a trunnion appendage and a space shuttle payload pallet simulator.

  19. Bounds on the mass and the moment of inertia of nonrotating neutron stars

    International Nuclear Information System (INIS)

    Sabbadini, A.G.

    1976-01-01

    Bounds are placed on the mass and the moment of inertia of relativistic, spherical, perfect fluid neutron stars, under minimal assumptions on the equation of state of neutron star matter above nuclear densities. The assumptions are: the pressure p, the density rho, and the derivative dp/d rho are positive. The equation of state is assumed to be known below the density rho 0 = 5 x 10 14 g/cm 3 . The upper bound on the mass of a nonrotating neutron star, under these assumptions, is found to be 5 M/sub solar mass/. Upper and lower bounds on the moment of inertia are derived: for a spherical star of given mass and radius (without assuming a specific equation of state in any density region); for a spherical neutron star of arbitrary mass and radius; for a spherical neutron star of given mass. These bounds are optimum ones, in the sense that there always exists a configuration consistent with the assumptions, having a moment of inertia equal to the bound. Using these results for the moment of inertia, the correction to the upper bound on the mass due to slow rotation is discussed

  20. Linear dynamic analysis of arbitrary thin shells modal superposition by using finite element method

    International Nuclear Information System (INIS)

    Goncalves Filho, O.J.A.

    1978-11-01

    The linear dynamic behaviour of arbitrary thin shells by the Finite Element Method is studied. Plane triangular elements with eighteen degrees of freedom each are used. The general equations of movement are obtained from the Hamilton Principle and solved by the Modal Superposition Method. The presence of a viscous type damping can be considered by means of percentages of the critical damping. An automatic computer program was developed to provide the vibratory properties and the dynamic response to several types of deterministic loadings, including temperature effects. The program was written in FORTRAN IV for the Burroughs B-6700 computer. (author)

  1. Advances of operational modal identification

    International Nuclear Information System (INIS)

    Zhang, L.

    2001-01-01

    Operational modal analysis has shown many advantages compared to the traditional one. In this paper, the development of ambient modal identification in time domain is summarized. The mathematical models for modal identification have been presented as unified framework for time domain (TD) System realization algorithms, such as polyrefence (PRCE), extended Ibrahim time domain (EITD) and eigensystem realization algorithm (ERA), etc., and recently developed Stochastic subspace technique (SST). The latest technique named as frequency domain decomposition (FDD) is introduced for operational modal identification, which has many advantages as a frequency domain (FD) technique. Applications of the operational modal analysis in civil and mechanical engineering have shown the success and accuracy of the advanced operational modal identification algorithms- FDD and SST techniques. The major issues of TD and FD operational modal identification are also discussed. (author)

  2. On the Force Drop Off Phenomenon in Shaker Testing in Experimental Modal Analysis

    Directory of Open Access Journals (Sweden)

    Paulo Sergio Varoto

    2002-01-01

    Full Text Available The Electrodynamic Vibration Exciter (shakers has been one of the most employed excitation sources in modal tests. The shaker is an electromechanical device that provides a mechanical motion due to the input signal sent to its coil. Despite being widely used, it is well known that the shaker interacts with the structure under test. In particular, when the structure passes through a given resonance, the force delivered by the shaker abruptly decreases, causing the so called drop off phenomenon. This paper aims to study this force drop off phenomenon in the single shaker modal testing. Analytical models are developed to help in understanding the physical principles involved in the interaction between the shaker and the structure under test. Experimental analyses are performed using different shakers as well as excitation signals, in order to evaluate the effects of the input signal, as well as the power amplifier operational modes, on the structure dynamics. Preliminary tests revealed that significant distortions might occur during vibration tests using shakers and these distortions significantly affect the determination of the structure response.

  3. A generalized modal shock spectra method for spacecraft loads analysis. [internal loads in a spacecraft structure subjected to a dynamic launch environment

    Science.gov (United States)

    Trubert, M.; Salama, M.

    1979-01-01

    Unlike an earlier shock spectra approach, generalization permits an accurate elastic interaction between the spacecraft and launch vehicle to obtain accurate bounds on the spacecraft response and structural loads. In addition, the modal response from a previous launch vehicle transient analysis with or without a dummy spacecraft - is exploited to define a modal impulse as a simple idealization of the actual forcing function. The idealized modal forcing function is then used to derive explicit expressions for an estimate of the bound on the spacecraft structural response and forces. Greater accuracy is achieved with the present method over the earlier shock spectra, while saving much computational effort over the transient analysis.

  4. Form birefringence analysis in a grating by means of modal theory; Analisis de la birrefringencia de forma en una rejilla mediante la teoria modal

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Ponce, G.; Solano, Cristina [Centro de Investigaciones en Optica A.C, Guanajuato (Mexico)

    2001-02-01

    The propagation of a plane electromagnetic wave through a grating using the modal theory is analyzed. The eigenproblem is solved in function of the ratio illumination wavelength {lambda} to grating period (d). When this ratio is much greater than one (quasiestatic limit), the grating shows a response similar to an uniaxial film. It is possible to approximate the eigenfunction for calculating the effective refractive indices of the birefringent element. This effect is called form birefringence and can be used to design retardation plates. [Spanish] En este trabajo se analiza la propagacion de una onda electromagnetica plana a traves de una rejilla utilizando la teoria modal. Estableciendo el problema de valor caracteristico se determina que la solucion es dependiente de la razon longitud de onda de iluminacion {lambda} y el periodo de la rejilla (d). En el caso {lambda}/d mayor que 1, conocido como el limite cuasiestatico, la rejilla se comporta como una pelicula uniaxial, obteniendose los indices ordinario y extraordinario a partir de una aproximacion a la ecuacion caracteristica. Este fenomeno, llamado birrefringencia de forma, puede emplearse para disenar elementos birrefringentes.

  5. Solitary plasmacytoma: population-based analysis of survival trends and effect of various treatment modalities in the USA.

    Science.gov (United States)

    Thumallapally, Nishitha; Meshref, Ahmed; Mousa, Mohammed; Terjanian, Terenig

    2017-01-05

    Solitary plasmacytoma (SP) is a localized neoplastic plasma cell disorder with an annual incidence of less than 450 cases. Given the rarity of this disorder, it is difficult to conduct large-scale population studies. Consequently, very limited information on the disorder is available, making it difficult to estimate the incidence and survival rates. Furthermore, limited information is available on the efficacy of various treatment modalities in relation to primary tumor sites. The data for this retrospective study were drawn from the Surveillance, Epidemiology and End Results (SEER) database, which comprises 18 registries; patient demographics, treatment modalities and survival rates were obtained for those diagnosed with SP from 1998 to 2007. Various prognostic factors were analyzed via Kaplan-Meier analysis and log-rank test, with 5-year relative survival rate defined as the primary outcome of interest. Cox regression analysis was employed in the multivariate analysis. The SEER search from 1998 to 2007 yielded records for 1691 SP patients. The median age at diagnosis was 63 years. The patient cohort was 62.4% male, 37.6% female, 80% Caucasian, 14.6% African American and 5.4% other races. Additionally, 57.8% had osseous plasmacytoma, and 31.9% had extraosseous involvement. Unspecified plasmacytoma was noted in 10.2% of patients. The most common treatment modalities were radiotherapy (RT) (48.8%), followed by combination surgery with RT (21.2%) and surgery alone (11.6%). Univariate analysis of prognostic factors revealed that the survival outcomes were better for younger male patients who received RT with surgery (p multiple myeloma (MM) was noted in 551 patients. Age >60 years was associated with a lower 5-year survival in patients who progressed to MM compared to those who were diagnosed initially with MM (15.1 vs 16.6%). Finally, those who received RT and progressed to MM still had a higher chance of survival than those who were diagnosed with MM initially and

  6. Systematic review of treatment modalities for gingival depigmentation: a random-effects poisson regression analysis.

    Science.gov (United States)

    Lin, Yi Hung; Tu, Yu Kang; Lu, Chun Tai; Chung, Wen Chen; Huang, Chiung Fang; Huang, Mao Suan; Lu, Hsein Kun

    2014-01-01

    Repigmentation variably occurs with different treatment methods in patients with gingival pigmentation. A systemic review was conducted of various treatment modalities for eliminating melanin pigmentation of the gingiva, comprising bur abrasion, scalpel surgery, cryosurgery, electrosurgery, gingival grafts, and laser techniques, to compare the recurrence rates (Rrs) of these treatment procedures. Electronic databases, including PubMed, Web of Science, Google, and Medline were comprehensively searched, and manual searches were conducted for studies published from January 1951 to June 2013. After applying inclusion and exclusion criteria, the final list of articles was reviewed in depth to achieve the objectives of this review. A Poisson regression was used to analyze the outcome of depigmentation using the various treatment methods. The systematic review was based on case reports mainly. In total, 61 eligible publications met the defined criteria. The various therapeutic procedures showed variable clinical results with a wide range of Rrs. A random-effects Poisson regression showed that cryosurgery (Rr = 0.32%), electrosurgery (Rr = 0.74%), and laser depigmentation (Rr = 1.16%) yielded superior result, whereas bur abrasion yielded the highest Rr (8.89%). Within the limit of the sampling level, the present evidence-based results show that cryosurgery exhibits the optimal predictability for depigmentation of the gingiva among all procedures examined, followed by electrosurgery and laser techniques. It is possible to treat melanin pigmentation of the gingiva with various methods and prevent repigmentation. Among those treatment modalities, cryosurgery, electrosurgery, and laser surgery appear to be the best choices for treating gingival pigmentation. © 2014 Wiley Periodicals, Inc.

  7. On modal cross-coupling in the asymptotic modal limit

    Science.gov (United States)

    Culver, Dean; Dowell, Earl

    2018-03-01

    The conditions under which significant modal cross-coupling occurs in dynamical systems responding to high-frequency, broadband forcing that excites many modes is studied. The modal overlap factor plays a key role in the analysis of these systems as the modal density (the ratio of number of modes to the frequency bandwidth) becomes large. The modal overlap factor is effectively the ratio of the width of a resonant peak (the damping ratio times the resonant frequency) to the average frequency interval between resonant peaks (or rather, the inverse of the modal density). It is shown that this parameter largely determines whether substantial modal cross-coupling occurs in a given system's response. Here, two prototypical systems are considered. The first is a simple rectangular plate whose significant modal cross-coupling is the exception rather than the norm. The second is a pair of rectangular plates attached at a point where significant modal cross-coupling is more likely to occur. We show that, for certain cases of modal density and damping, non-negligible cross coupling occurs in both systems. Under similar circumstances, the constraint force between the two plates in the latter system becomes broadband. The implications of this for using Asymptotic Modal Analysis (AMA) in multi-component systems are discussed.

  8. Structured and Sparse Canonical Correlation Analysis as a Brain-Wide Multi-Modal Data Fusion Approach.

    Science.gov (United States)

    Mohammadi-Nejad, Ali-Reza; Hossein-Zadeh, Gholam-Ali; Soltanian-Zadeh, Hamid

    2017-07-01

    Multi-modal data fusion has recently emerged as a comprehensive neuroimaging analysis approach, which usually uses canonical correlation analysis (CCA). However, the current CCA-based fusion approaches face problems like high-dimensionality, multi-collinearity, unimodal feature selection, asymmetry, and loss of spatial information in reshaping the imaging data into vectors. This paper proposes a structured and sparse CCA (ssCCA) technique as a novel CCA method to overcome the above problems. To investigate the performance of the proposed algorithm, we have compared three data fusion techniques: standard CCA, regularized CCA, and ssCCA, and evaluated their ability to detect multi-modal data associations. We have used simulations to compare the performance of these approaches and probe the effects of non-negativity constraint, the dimensionality of features, sample size, and noise power. The results demonstrate that ssCCA outperforms the existing standard and regularized CCA-based fusion approaches. We have also applied the methods to real functional magnetic resonance imaging (fMRI) and structural MRI data of Alzheimer's disease (AD) patients (n = 34) and healthy control (HC) subjects (n = 42) from the ADNI database. The results illustrate that the proposed unsupervised technique differentiates the transition pattern between the subject-course of AD patients and HC subjects with a p-value of less than 1×10 -6 . Furthermore, we have depicted the brain mapping of functional areas that are most correlated with the anatomical changes in AD patients relative to HC subjects.

  9. Non-modal stability analysis and transient growth in a magnetized Vlasov plasma

    KAUST Repository

    Ratushnaya, V.

    2014-12-01

    Collisionless plasmas, such as those encountered in tokamaks, exhibit a rich variety of instabilities. The physical origin, triggering mechanisms and fundamental understanding of many plasma instabilities, however, are still open problems. We investigate the stability properties of a 3-dimensional collisionless Vlasov plasma in a stationary homogeneous magnetic field. We narrow the scope of our investigation to the case of Maxwellian plasma and examine its evolution with an electrostatic approximation. For the first time using a fully kinetic approach we show the emergence of the local instability, a transient growth, followed by classical Landau damping in a stable magnetized plasma. We show that the linearized Vlasov operator is non-normal leading to the algebraic growth of the perturbations using non-modal stability theory. The typical time scales of the obtained instabilities are of the order of several plasma periods. The first-order distribution function and the corresponding electric field are calculated and the dependence on the magnetic field and perturbation parameters is studied. Our results offer a new scenario of the emergence and development of plasma instabilities on the kinetic scale.

  10. Dynamic modeling and characteristics analysis of a modal-independent linear ultrasonic motor.

    Science.gov (United States)

    Li, Xiang; Yao, Zhiyuan; Zhou, Shengli; Lv, Qibao; Liu, Zhen

    2016-12-01

    In this paper, an integrated model is developed to analyze the fundamental characteristics of a modal-independent linear ultrasonic motor with double piezoelectric vibrators. The energy method is used to model the dynamics of the two piezoelectric vibrators. The interface forces are coupled into the dynamic equations of the two vibrators and the moving platform, forming a whole machine model of the motor. The behavior of the force transmission of the motor is analyzed via the resulting model to understand the drive mechanism. In particular, the relative contact length is proposed to describe the intermittent contact characteristic between the stator and the mover, and its role in evaluating motor performance is discussed. The relations between the output speed and various inputs to the motor and the start-stop transients of the motor are analyzed by numerical simulations, which are validated by experiments. Furthermore, the dead-zone behavior is predicted and clarified analytically using the proposed model, which is also observed in experiments. These results are useful for designing servo control scheme for the motor. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Clinical characteristics and surgical modality of plasma cell mastitis: analysis of 91 cases.

    Science.gov (United States)

    Ming, Jia; Meng, Gang; Yuan, Qiaoying; Zhong, Ling; Tang, Peng; Zhang, Kongyong; Chen, Qingqiu; Fan, Linjun; Jiang, Jun

    2013-01-01

    The objective of this study was to investigate the clinical characteristics and surgical modality of plasma cell mastitis (PCM). A total of 93 breasts of 91 female patients with PCM from June 2003 to June 2010 (unilateral in 89 patients and bilateral in two patients) were investigated in this study. All breasts were divided into two groups: the direct excision group (DE group) received focused excision and nipple retraction correction; and the incision drainage group (ID group) received these procedures only in the event of failing at least two incision drainages. Clinical characteristics, extent of excision, and prognosis were compared between two groups. There were 53 breasts in the DE group and 40 breasts in the ID group. No significant differences were noted in the number of retracted nipples and abscesses in the first visit or extent of disease between two groups (P > 0.05). However, during surgery, 3.85 ± 0.97 abscesses per breast were detectable in the ID group, which was significantly higher than 1.21 ± 0.06 abscesses per breast in the DE group. The ID group had significantly higher inflammation and excised extent compared with the DE group (P culture was negative for pus of 39 nonrupturing abscesses. Congenital nipple retraction may be the primary cause of PCM. Early and complete focused excision and nipple retraction correction are effective treatment methods.

  12. Non-modal stability analysis and transient growth in a magnetized Vlasov plasma

    KAUST Repository

    Ratushnaya, V.; Samtaney, Ravi

    2014-01-01

    Collisionless plasmas, such as those encountered in tokamaks, exhibit a rich variety of instabilities. The physical origin, triggering mechanisms and fundamental understanding of many plasma instabilities, however, are still open problems. We investigate the stability properties of a 3-dimensional collisionless Vlasov plasma in a stationary homogeneous magnetic field. We narrow the scope of our investigation to the case of Maxwellian plasma and examine its evolution with an electrostatic approximation. For the first time using a fully kinetic approach we show the emergence of the local instability, a transient growth, followed by classical Landau damping in a stable magnetized plasma. We show that the linearized Vlasov operator is non-normal leading to the algebraic growth of the perturbations using non-modal stability theory. The typical time scales of the obtained instabilities are of the order of several plasma periods. The first-order distribution function and the corresponding electric field are calculated and the dependence on the magnetic field and perturbation parameters is studied. Our results offer a new scenario of the emergence and development of plasma instabilities on the kinetic scale.

  13. Stokes-space analysis of modal dispersion in fibers with multiple mode transmission.

    Science.gov (United States)

    Antonelli, Cristian; Mecozzi, Antonio; Shtaif, Mark; Winzer, Peter J

    2012-05-21

    Modal dispersion (MD) in a multimode fiber may be considered as a generalized form of polarization mode dispersion (PMD) in single mode fibers. Using this analogy, we extend the formalism developed for PMD to characterize MD in fibers with multiple spatial modes. We introduce a MD vector defined in a D-dimensional extended Stokes space whose square length is the sum of the square group delays of the generalized principal states. For strong mode coupling, the MD vector undertakes a D-dimensional isotropic random walk, so that the distribution of its length is a chi distribution with D degrees of freedom. We also characterize the largest differential group delay, that is the difference between the delays of the fastest and the slowest principal states, and show that it too is very well approximated by a chi distribution, although in general with a smaller number of degrees of freedom. Finally, we study the spectral properties of MD in terms of the frequency autocorrelation functions of the MD vector, of the square modulus of the MD vector, and of the largest differential group delay. The analytical results are supported by extensive numerical simulations.

  14. Cross-Modality 2D-3D Face Recognition via Multiview Smooth Discriminant Analysis Based on ELM

    Directory of Open Access Journals (Sweden)

    Yi Jin

    2014-01-01

    Full Text Available In recent years, 3D face recognition has attracted increasing attention from worldwide researchers. Rather than homogeneous face data, more and more applications require flexible input face data nowadays. In this paper, we propose a new approach for cross-modality 2D-3D face recognition (FR, which is called Multiview Smooth Discriminant Analysis (MSDA based on Extreme Learning Machines (ELM. Adding the Laplacian penalty constrain for the multiview feature learning, the proposed MSDA is first proposed to extract the cross-modality 2D-3D face features. The MSDA aims at finding a multiview learning based common discriminative feature space and it can then fully utilize the underlying relationship of features from different views. To speed up the learning phase of the classifier, the recent popular algorithm named Extreme Learning Machine (ELM is adopted to train the single hidden layer feedforward neural networks (SLFNs. To evaluate the effectiveness of our proposed FR framework, experimental results on a benchmark face recognition dataset are presented. Simulations show that our new proposed method generally outperforms several recent approaches with a fast training speed.

  15. Adaptive operational modal identification for slow linear time-varying structures based on frozen-in coefficient method and limited memory recursive principal component analysis

    Science.gov (United States)

    Wang, Cheng; Guan, Wei; Wang, J. Y.; Zhong, Bineng; Lai, Xiongming; Chen, Yewang; Xiang, Liang

    2018-02-01

    To adaptively identify the transient modal parameters for linear weakly damped structures with slow time-varying characteristics under unmeasured stationary random ambient loads, this paper proposes a novel operational modal analysis (OMA) method based on the frozen-in coefficient method and limited memory recursive principal component analysis (LMRPCA). In the modal coordinate, the random vibration response signals of mechanical weakly damped structures can be decomposed into the inner product of modal shapes and modal responses, from which the natural frequencies and damping ratios can be well acquired by single-degree-of-freedom (SDOF) identification approach such as FFT. Hence, for the OMA method based on principal component analysis (PCA), it becomes very crucial to examine the relation between the transformational matrix and the modal shapes matrix, to find the association between the principal components (PCs) matrix and the modal responses matrix, and to turn the operational modal parameter identification problem into PCA of the stationary random vibration response signals of weakly damped mechanical structures. Based on the theory of "time-freezing", the method of frozen-in coefficient, and the assumption of "short time invariant" and "quasistationary", the non-stationary random response signals of the weakly damped and slow linear time-varying structures (LTV) can approximately be seen as the stationary random response time series of weakly damped and linear time invariant structures (LTI) in a short interval. Thus, the adaptive identification of time-varying operational modal parameters is turned into decompositing the PCs of stationary random vibration response signals subsection of weakly damped mechanical structures after choosing an appropriate limited memory window. Finally, a three-degree-of-freedom (DOF) structure with weakly damped and slow time-varying mass is presented to illustrate this method of identification. Results show that the LMRPCA

  16. Load Estimation from Modal Parameters

    DEFF Research Database (Denmark)

    Aenlle, Manuel López; Brincker, Rune; Fernández, Pelayo Fernández

    2007-01-01

    In Natural Input Modal Analysis the modal parameters are estimated just from the responses while the loading is not recorded. However, engineers are sometimes interested in knowing some features of the loading acting on a structure. In this paper, a procedure to determine the loading from a FRF m...

  17. Cost-effectiveness analysis of screening modalities for breast cancer in Japan with special reference to women aged 40-49 years

    International Nuclear Information System (INIS)

    Ohnuki, Koji; Kuriyama, Shinichi; Shoji, Narumi; Tsuji, Ichiro; Ohuchi, Noriaki; Nishino, Yoshikazu

    2006-01-01

    Although the introduction of screening mammography in Japan would be expected to reduce mortality from breast cancer, the optimal screening modality in terms of cost-effectiveness remains unclear. We compared the cost-effectiveness ratio, defined as the cost required for a life-year saved, among the following three strategies: annual clinical breast examination; annual clinical breast examination combined with mammography; and biennial clinical breast examination combined with mammography for women aged 30-79 years using a hypothetical cohort of 100,000. The sensitivity, specificity and early breast cancer rates were derived from studies conducted from 1995 to 2000 in Miyagi Prefecture. The treatment costs were based on a questionnaire survey conducted at 13 institutions in Japan. We used updated parameters that were needed in the analysis. Although the effectiveness of treatment in terms of the number of expected survival years was highest for annual combined modality, biennial combined modality had a higher cost-effectiveness ratio, followed by annual combined modality and annual clinical breast examination in all age groups. In women aged 40-49 years, annual combined modality saved 852.9 lives and the cost/survival duration was 3,394,300 yen/year, whereas for biennial combined modality the corresponding figures were 833.8 and 2,025,100 yen/year, respectively. Annual clinical breast examination did not confer any advantages in terms of effectiveness (815.5 lives saved) or cost-effectiveness (3,669,900 yen/year). While the annual combined modality was the most effective with respect to life-years saved among women aged 40-49 years, biennial combined modality was found to provide the highest cost-effectiveness. (author)

  18. Sub-Nyquist signal-reconstruction-free operational modal analysis and damage detection in the presence of noise

    Science.gov (United States)

    Gkoktsi, Kyriaki; Giaralis, Agathoklis; TauSiesakul, Bamrung

    2016-04-01

    Motivated by a need to reduce energy consumption in wireless sensors for vibration-based structural health monitoring (SHM) associated with data acquisition and transmission, this paper puts forth a novel approach for undertaking operational modal analysis (OMA) and damage localization relying on compressed vibrations measurements sampled at rates well below the Nyquist rate. Specifically, non-uniform deterministic sub-Nyquist multi-coset sampling of response acceleration signals in white noise excited linear structures is considered in conjunction with a power spectrum blind sampling/estimation technique which retrieves/samples the power spectral density matrix from arrays of sensors directly from the sub-Nyquist measurements (i.e., in the compressed domain) without signal reconstruction in the time-domain and without posing any signal sparsity conditions. The frequency domain decomposition algorithm is then applied to the power spectral density matrix to extract natural frequencies and mode shapes as a standard OMA step. Further, the modal strain energy index (MSEI) is considered for damage localization based on the mode shapes extracted directly from the compressed measurements. The effectiveness and accuracy of the proposed approach is numerically assessed by considering simulated vibration data pertaining to a white-noise excited simply supported beam in healthy and in 3 damaged states, contaminated with Gaussian white noise. Good accuracy is achieved in estimating mode shapes (quantified in terms of the modal assurance criterion) and natural frequencies from an array of 15 multi-coset devices sampling at a 70% slower than the Nyquist frequency rate for SNRs as low as 10db. Damage localization of equal level/quality is also achieved by the MSEI applied to mode shapes derived from noisy sub-Nyquist (70% compression) and Nyquist measurements for all damaged states considered. Overall, the furnished numerical results demonstrate that the herein considered sub

  19. NMR-based metabonomic analysis of MnO-embedded iron oxide nanoparticles as potential dual-modal contrast agents

    Science.gov (United States)

    Li, Jinquan; Zhou, Zijian; Feng, Jianghua; Cai, Shuhui; Gao, Jinhao; Chen, Zhong

    2014-05-01

    MnO-embedded iron oxide nanoparticles (MnIO-NPs) can be treated as potential dual-modal contrast agents. However, their overall bio-effects and potential toxicity remain unknown. In this study, the metabolic effects of MnIO-NPs (dosed at 1 and 5 mg Fe/kg) on Sprague-Dawley rats were investigated using metabonomic analysis, histopathological examination, and conventional biochemical analysis. The histological changes included a focal inflammation in the liver at high-dose and a slightly enlarged area of splenic white pulp after 48 h post-dose. Blood biochemical analysis showed that albumin, globulins, aspartate aminotransferase, lactate dehydrogenase, blood urea nitrogen, and glucose changed distinctly compared to the control. The metabonomic analysis of body fluids (serum and urine) and tissues (liver, kidney, and spleen) indicated that MnIO-NPs induced metabolic perturbation in rats including energy, nucleotides, amino acids and phospholipid metabolisms. Besides, the variations of supportive nutrients: valine, leucine, isoleucine, nicotinamide adenine dinucleotide (phosphate), and nicotinamide, and the conjugation substrates: glycine, taurine, glutamine, glutathione, and methyl donors (formate, sarcosine, dimethylglycine, choline, and betaine) were involved in detoxification reaction of MnIO-NPs. The obtained information would provide identifiable ground for the candidate selection and optimization.

  20. Coupled response spectrum analysis of secondary systems using uncoupled modal properties

    International Nuclear Information System (INIS)

    Gupta, A.K.; Jaw Jingwen

    1986-01-01

    A method of performing coupled response spectrum analysis of secondary systems is presented. The response spectrum specified at the base of the primary system is used as the input. The complex coupled mode shapes along with frequencies and damping values are calculated using an efficient and accurate perturbation scheme. The new method is applied to a 2 DOF secondary system coupled with a 6 DOF secondary system. The masses and the stiffness of the secondary system are varied to get nine different cases. The coupled system is subjected to El Centro (S00E, 1940) ground motion. It is shown that the response values from the present method are in good agreement with those from the coupled time history analysis. The conventional floor response spectrum method gives response values which are consistently much higher than the corresponding values from the time history analysis. It is concluded that the present method is sufficiently straightforward and efficient, and that it yields accurate response values. (orig.)

  1. Development of Modal Analysis for the Study of Global Modes in High Speed Boundary Layer Flows

    Science.gov (United States)

    Brock, Joseph Michael

    Boundary layer transition for compressible flows remains a challenging and unsolved problem. In the context of high-speed compressible flow, transitional and turbulent boundary-layers produce significantly higher surface heating caused by an increase in skin-friction. The higher heating associated with transitional and turbulent boundary layers drives thermal protection systems (TPS) and mission trajectory bounds. Proper understanding of the mechanisms that drive transition is crucial to the successful design and operation of the next generation spacecraft. Currently, prediction of boundary-layer transition is based on experimental efforts and computational stability analysis. Computational analysis, anchored by experimental correlations, offers an avenue to assess/predict stability at a reduced cost. Classical methods of Linearized Stability Theory (LST) and Parabolized Stability Equations (PSE) have proven to be very useful for simple geometries/base flows. Under certain conditions the assumptions that are inherent to classical methods become invalid and the use of LST/PSE is inaccurate. In these situations, a global approach must be considered. A TriGlobal stability analysis code, Global Mode Analysis in US3D (GMAUS3D), has been developed and implemented into the unstructured solver US3D. A discussion of the methodology and implementation will be presented. Two flow configurations are presented in an effort to validate/verify the approach. First, stability analysis for a subsonic cylinder wake is performed and results compared to literature. Second, a supersonic blunt cone is considered to directly compare LST/PSE analysis and results generated by GMAUS3D.

  2. Modal analysis of a small vertical axis wind turbine (Type DARRIEUS

    Directory of Open Access Journals (Sweden)

    Ion NILA

    2012-06-01

    Full Text Available This paper reports a brief study on free vibration analysis for determining parameters such as natural frequencies and mode shapes for vertical axis wind turbines (VAWT for an urban application. This study is focused on numerical work using available finite element software. For further understanding of the wind turbine dynamic analysis, two vibration parameters of dynamic response have been studied, namely natural frequencies and mode shapes.Block Lanczos method has been used to analyze the natural frequency while wind turbine mode shapes have been utilized because of their accuracy and faster solution. In this problem 12 modes of structure have been extracted.

  3. Modal analysis and simulation on effect of correction factor (cf) in ...

    African Journals Online (AJOL)

    DR OKE

    Determination of load distribution along the tooth width during meshing process is a basis for gear drive design, due to the ... simulation of static and dynamic contact analysis particularly for the contact/impact problems of gear drives. ..... three-dimensional contact calculations, Mechanism and Machine Theory, Vol.62, pp.

  4. Modal Analysis Using the Singular Value Decomposition and Rational Fraction Polynomials

    Science.gov (United States)

    2017-04-06

    also consistent. In the subsequent analysis, the normal direction at each node is computed using the cross product of the connected element edges...For this mode in particular, the revised RFP mode shape is much cleaner than the original SVD mode shape. The algorithm for computing the revised

  5. Analysis of the modal behavior of an antiguide diode laser array with Talbot filter

    NARCIS (Netherlands)

    van Eijk, P.D.; van Eijk, Pieter D.; Reglat, Muriel; Vassilief, Georges; Krijnen, Gijsbertus J.M.; Driessen, A.; Mouthaan, A.J.

    An analysis of the filtering of the array modes in a resonant optical waveguide (ROW) array of antiguides by a diffractive spatial filter (a Talbot filter) is presented. A dispersion relation is derived for the array modes, allowing the calculation of the field distribution. The filtering is

  6. Evaluation of photoshop based image analysis in cytologic diagnosis of pleural fluid in comparison with conventional modalities.

    Science.gov (United States)

    Jafarian, Amir Hossein; Tasbandi, Aida; Mohamadian Roshan, Nema

    2018-04-19

    The aim of this study is to investigate and compare the results of digital image analysis in pleural effusion cytology samples with conventional modalities. In this cross-sectional study, 53 pleural fluid cytology smears from Qaem hospital pathology department, located in Mashhad, Iran were investigated. Prior to digital analysis, all specimens were evaluated by two pathologists and categorized into three groups as: benign, suspicious, and malignant. Using an Olympus microscope and Olympus DP3 digital camera, digital images from cytology slides were captured. Appropriate images (n = 130) were separately imported to Adobe Photoshop CS5 and parameters including area and perimeter, circularity, Gray Value mean, integrated density, and nucleus to cytoplasm area ratio were analyzed. Gray Value mean, nucleus to cytoplasm area ratio, and circularity showed the best sensitivity and specificity rates as well as significant differences between all groups. Also, nucleus area and perimeter showed a significant relation between suspicious and malignant groups with benign group. Whereas, there was no such difference between suspicious and malignant groups. We concluded that digital image analysis is welcomed in the field of research on pleural fluid smears as it can provide quantitative data to apply various comparisons and reduce interobserver variation which could assist pathologists to achieve a more accurate diagnosis. © 2018 Wiley Periodicals, Inc.

  7. Small disturbance voltage stability assessment of power systems by modal analysis and dynamic simulation

    International Nuclear Information System (INIS)

    Amjady, Nima; Ansari, Mohammad Reza

    2008-01-01

    The introduction of liberalized electricity markets in many countries has resulted in more highly stressed power systems. On the other hand, operating points of a power system are acceptable in the feasible region, which is surrounded by the borders of different stabilities. Power system instability is critical for all participants of the electricity market. Determination of different stability margins can result in the optimum utilization of power system with minimum risk. This paper focuses on the small disturbance voltage stability, which is an important subset of the power system global stability. This kind of voltage stability is usually evaluated by static analysis tools such as continuation power flow, while it essentially has dynamic nature. Besides, a combination of linear and nonlinear analysis tools is required to correctly analyze it. In this paper, a hybrid evaluation method composed of static, dynamic, linear, and nonlinear analysis tools is proposed for this purpose. Effect of load scenario, generation pattern, branch and generator contingency on the small disturbance voltage stability are evaluated by the hybrid method. The test results are given for New England and IEEE68 bus test systems. (author)

  8. Modal Analysis and Experimental Determination of Optimum Tool Shank Overhang of a Lathe Machine

    Directory of Open Access Journals (Sweden)

    Nabin SARDAR

    2008-12-01

    Full Text Available Vibration of Tool Shank of a cutting tool has large influence on tolerances and surface finish of products. Frequency and amplitude of vibrations depend on the overhang of the shank of the cutting tool. In turning operations, when the tool overhang is about 2 times of the tool height, the amplitude of the vibration is almost zero and dimensional tolerances and surface finish of the product becomes high. In this paper, the above statement is verified firstly by using a finite element analysis of the cutting tool with ANSYS software package and secondly, with experimental verification with a piezoelectric sensor.

  9. Modal analysis and cut-off conditions of multichannel surface-acoustic-waveguide structures.

    Science.gov (United States)

    Griffel, G; Golan, G; Ruschin, S; Seidman, A; Croitoru, N

    1988-01-01

    Multichannel guides for surface acoustic waves can improve the efficiency of SAW (surface acoustic-wave) devices significantly. Focusing, steering, and modulating the propagating acoustical modes can be achieved similarly to optical waveguided devices. A general formulation is presented for the analysis of the lateral waveguiding properties of Rayleigh modes in surfaces loaded with deposited strips of different materials. General expressions are obtained for the number of modes and cutoff conditions in these structures. As examples of applications, a simple directional coupler and an electrically controlled coupler are proposed.

  10. Modal spectrum analysis of piping systems under water-hammer loading: Spectra examination

    International Nuclear Information System (INIS)

    Meder, G.; Grams, J.

    1983-01-01

    In the last few years the dynamic calculation with spectra of piping systems under fluid-hammer has been developed. In comparison with the time-history solution method the spectra method has important advantages because it can calculate a bounded solution. In this bounded solution, the inevitable uncertainties of the time-dependent forces and the uncertainties in the modeling of the piping system are taken into account. The spectra also give valuable information about the frequency content of the time-dependent forces, which is important too for correct time-step selection when using the time-history-method. Using the spectra method, the dynamic calculation is divided into stages. First and most essential is the calculation of the spectra. Secondly, a form of superposition is used for combining the results from each eigenmode analysis. In this paper the first stage, calculation of the spectra due to fluid hammer loading, will be examined. An approximate method for load calculation is shown, whereby the results from a change of fluid-dynamic parameters can be quickly determined without making a full numerical analysis. When changes are made in fluiddynamic parameters, the normal result is a change of shift in the frequency content of the spectra. However, for changes in certain parameters, only the force amplitudes are changed. Both types of changes will be discussed. (orig./RW)

  11. Analysis of self-homodyne detection for 6-mode fiber with low-modal crosstalk

    Science.gov (United States)

    Guo, Meng; Hu, Guijun

    2017-12-01

    In this paper, we present an appropriate analysis on self-homodyne coherent system with 56 × 5 × 3 Gb / s WDM-PDM-MDM quadrature phase-shift keying (QPSK) signals using 6-mode weakly coupled few mode fiber. The mode division technology can effectively improve the spectral efficiency (SE) of self-homodyne detection. Of all the LP modes, LP01 mode is used to transmit the pilot tone (PT), while the others for signal channels. The influence of inter-mode crosstalk is analyzed. The proposed frequency domain MMA shows a better BER performance for intra-mode crosstalk elimination. The path-length misalignment's influence caused by mode differential group delay (MDGD) is also investigated. The system tolerance for different laser's line-width is compared as well as the influence of PT filter's bandwidth.

  12. Integration of XNAT/PACS, DICOM, and research software for automated multi-modal image analysis

    Science.gov (United States)

    Gao, Yurui; Burns, Scott S.; Lauzon, Carolyn B.; Fong, Andrew E.; James, Terry A.; Lubar, Joel F.; Thatcher, Robert W.; Twillie, David A.; Wirt, Michael D.; Zola, Marc A.; Logan, Bret W.; Anderson, Adam W.; Landman, Bennett A.

    2013-03-01

    Traumatic brain injury (TBI) is an increasingly important public health concern. While there are several promising avenues of intervention, clinical assessments are relatively coarse and comparative quantitative analysis is an emerging field. Imaging data provide potentially useful information for evaluating TBI across functional, structural, and microstructural phenotypes. Integration and management of disparate data types are major obstacles. In a multi-institution collaboration, we are collecting electroencephalogy (EEG), structural MRI, diffusion tensor MRI (DTI), and single photon emission computed tomography (SPECT) from a large cohort of US Army service members exposed to mild or moderate TBI who are undergoing experimental treatment. We have constructed a robust informatics backbone for this project centered on the DICOM standard and eXtensible Neuroimaging Archive Toolkit (XNAT) server. Herein, we discuss (1) optimization of data transmission, validation and storage, (2) quality assurance and workflow management, and (3) integration of high performance computing with research software.

  13. Automatic registration of multi-modal microscopy images for integrative analysis of prostate tissue sections

    International Nuclear Information System (INIS)

    Lippolis, Giuseppe; Edsjö, Anders; Helczynski, Leszek; Bjartell, Anders; Overgaard, Niels Chr

    2013-01-01

    Prostate cancer is one of the leading causes of cancer related deaths. For diagnosis, predicting the outcome of the disease, and for assessing potential new biomarkers, pathologists and researchers routinely analyze histological samples. Morphological and molecular information may be integrated by aligning microscopic histological images in a multiplex fashion. This process is usually time-consuming and results in intra- and inter-user variability. The aim of this study is to investigate the feasibility of using modern image analysis methods for automated alignment of microscopic images from differently stained adjacent paraffin sections from prostatic tissue specimens. Tissue samples, obtained from biopsy or radical prostatectomy, were sectioned and stained with either hematoxylin & eosin (H&E), immunohistochemistry for p63 and AMACR or Time Resolved Fluorescence (TRF) for androgen receptor (AR). Image pairs were aligned allowing for translation, rotation and scaling. The registration was performed automatically by first detecting landmarks in both images, using the scale invariant image transform (SIFT), followed by the well-known RANSAC protocol for finding point correspondences and finally aligned by Procrustes fit. The Registration results were evaluated using both visual and quantitative criteria as defined in the text. Three experiments were carried out. First, images of consecutive tissue sections stained with H&E and p63/AMACR were successfully aligned in 85 of 88 cases (96.6%). The failures occurred in 3 out of 13 cores with highly aggressive cancer (Gleason score ≥ 8). Second, TRF and H&E image pairs were aligned correctly in 103 out of 106 cases (97%). The third experiment considered the alignment of image pairs with the same staining (H&E) coming from a stack of 4 sections. The success rate for alignment dropped from 93.8% in adjacent sections to 22% for sections furthest away. The proposed method is both reliable and fast and therefore well suited

  14. MODALITIES OF LOCAL DEBT ANALYSIS IN THE NORTH-WEST REGION OF ROMANIA

    Directory of Open Access Journals (Sweden)

    Ioan BĂTRÂNCEA

    2016-12-01

    Full Text Available Public debt is a topic of great interest, problem tracked over the years and has worsened with the outbreak of the second wave of financial crisis around the world, namely the sovereign debt crisis . Among the countries affected by this phenomenon are, along with countries like Greece, Italy, Spain and Portugal, our country whose public debt has doubled in the past four years and will affect future regional development in Romania. In late 2010, the Romanian government debt (according to ESA 95 methodology reached 31.02 % of GDP. Although this indicator falls comfortably within the 60 % of GDP Maastricht Treaty, its growth rate remains worrying. In 2012 there was a level of government debt ( EU methodology - ESC 95 37.8 % of GDP, and for 2013 the estimated level of government debt is below 36.4 % of GDP ( 51 billion euro ranging is below the Maastricht Treaty provided for 60% of GDP, an advantage for Romania , given the new rules on public debt and budget deficit introduced by the new rules of economic governance at the European level , the concept of prudent fiscal policy becomes central . This is a reason for adopting a pro- active stance by continuing fiscal consolidation measures. That is why in this paper the authors present an analysis of public debt based on a correlated system of indicators.

  15. Articulatory mediation of speech perception: a causal analysis of multi-modal imaging data.

    Science.gov (United States)

    Gow, David W; Segawa, Jennifer A

    2009-02-01

    The inherent confound between the organization of articulation and the acoustic-phonetic structure of the speech signal makes it exceptionally difficult to evaluate the competing claims of motor and acoustic-phonetic accounts of how listeners recognize coarticulated speech. Here we use Granger causation analyzes of high spatiotemporal resolution neural activation data derived from the integration of magnetic resonance imaging, magnetoencephalography and electroencephalography, to examine the role of lexical and articulatory mediation in listeners' ability to use phonetic context to compensate for place assimilation. Listeners heard two-word phrases such as pen pad and then saw two pictures, from which they had to select the one that depicted the phrase. Assimilation, lexical competitor environment and the phonological validity of assimilation context were all manipulated. Behavioral data showed an effect of context on the interpretation of assimilated segments. Analysis of 40 Hz gamma phase locking patterns identified a large distributed neural network including 16 distinct regions of interest (ROIs) spanning portions of both hemispheres in the first 200 ms of post-assimilation context. Granger analyzes of individual conditions showed differing patterns of causal interaction between ROIs during this interval, with hypothesized lexical and articulatory structures and pathways driving phonetic activation in the posterior superior temporal gyrus in assimilation conditions, but not in phonetically unambiguous conditions. These results lend strong support for the motor theory of speech perception, and clarify the role of lexical mediation in the phonetic processing of assimilated speech.

  16. Modal analysis and acoustic transmission through offset-core honeycomb sandwich panels

    Science.gov (United States)

    Mathias, Adam Dustin

    The work presented in this thesis is motivated by an earlier research that showed that double, offset-core honeycomb sandwich panels increased thermal resistance and, hence, decreased heat transfer through the panels. This result lead to the hypothesis that these panels could be used for acoustic insulation. Using commercial finite element modeling software, COMSOL Multiphysics, the acoustical properties, specifically the transmission loss across a variety of offset-core honeycomb sandwich panels, is studied for the case of a plane acoustic wave impacting the panel at normal incidence. The transmission loss results are compared with those of single-core honeycomb panels with the same cell sizes. The fundamental frequencies of the panels are also computed in an attempt to better understand the vibrational modes of these particular sandwich-structured panels. To ensure that the finite element analysis software is adequate for the task at hand, two relevant benchmark problems are solved and compared with theory. Results from these benchmark results compared well to those obtained from theory. Transmission loss results from the offset-core honeycomb sandwich panels show increased transmission loss, especially for large cell honeycombs when compared to single-core honeycomb panels.

  17. ANALYSIS OF RESPIRATORY DEPOSITION OF INHALED PARTICLES FOR DIFFERENT DOSE METRICS: COMPARISON OF NUMBER, SURFACE AREA AND MASS DOSE OF TYPICAL AMBIENT BI-MODAL AEROSOLS

    Science.gov (United States)

    ANALYSIS OF RESPIRATORY DEPOSITION OF INHALED PARTICLES FOR DIFFERENT DOSE METRICS: COMPARISON OF NUMBER, SURFACE AREA AND MASS DOSE OF TYPICAL AMBIENT BI-MODAL AEROSOLS.Chong S. Kim, SC. Hu*, PA Jaques*, US EPA, National Health and Environmental Effects Research Laboratory, ...

  18. Some remarks on the influence of temperature-variations, non-linearities, repeatability and ageing on modal-analysis for structural health monitoring of real bridges

    Directory of Open Access Journals (Sweden)

    Maas Stefan

    2015-01-01

    Full Text Available Structural Health Monitoring (SHM intends to identify damage by changes of characteristics as for instance the modal parameters. The eigenfrequencies, mode-shapes and damping-values are either directly used as damage indicators or the changes of derived parameters are analysed, such as e.g. flexibilities or updated finite element models. One common way is a continuous monitoring under environmental excitation forces, such as wind or traffic, i.e. the so-called output-only modal analysis. Alternatively, a forced measured external excitation in distinct time-intervals may be used for input-output modal analysis. Both methods are limited by the precision or the repeatability under real-life conditions at site. The paper will summarize several field tests of artificially step-by-step damaged bridges prior to their final demolishment and it will show the changes of eigenfrequencies due to induced artificial damage. Additionally, some results of a monitoring campaign of a healthy bridge in Luxembourg are presented. Reinforced concrete shows non-linear behaviour in the sense that modal parameters depend on the excitation force amplitude, i.e. higher forces lead often to lower eigenfrequencies than smaller forces. Furthermore, the temperature of real bridges is neither constant in space nor in time, while for instance the stiffness of asphalt is strongly dependant on it. Finally, ageing as such can also change a bridge’s stiffness and its modal parameters, e.g. because creep and shrinkage of concrete or ageing of elastomeric bearing pads influence their modulus of elasticity. These effects cannot be considered as damage, though they influence the measurement of modal parameters and hinder damage detection.

  19. Fano-Agarwal couplings and non-rotating wave approximation in single-photon timed Dicke subradiance

    Science.gov (United States)

    Mirza, Imran M.; Begzjav, Tuguldur

    2016-04-01

    Recently a new class of single-photon timed Dicke (TD) subradiant states has been introduced with possible applications in single-photon-based quantum information storage and on demand ultrafast retrieval (Scully M. O., Phys. Rev. Lett., 115 (2015) 243602). However, the influence of any kind of virtual processes on the decay of these new kind of subradiant states has been left as an open question. In the present paper, we focus on this problem in detail. In particular, we investigate how pure Fano-Agarwal couplings and other virtual processes arising from non-rotating wave approximation impact the decay of otherwise sub- and superradiant states. In addition to the overall virtual couplings among all TD states, we also focus on the dominant role played by the couplings between specific TD states.

  20. Symbol Digit Modalities Test adaptation for Magnetic Resonance Imaging environment: A systematic review and meta-analysis.

    Science.gov (United States)

    Silva, P H R; Spedo, C T; Barreira, A A; Leoni, R F

    2018-02-01

    The Symbol Digit Modalities Test (SDMT) is widely used for cognitive evaluation of information processing speed (IPS), required in many cognitive operations. Despite being unspecific for different neurological disorders, it is sensitive to assess impaired performance related to stroke, Parkinson's disease, traumatic brain injury, and multiple sclerosis. However, in addition to evaluate the presence and severity of IPS impairment, it is of interest to determine the localization and integration of brain regions responsible for the functions assessed by the SDMT. To review the studies that adapted the SDMT to the magnetic resonance environment and obtain the brain areas associated with the performance of the task in healthy subjects with a meta-analysis. A systematic review was performed using ten studies published between 1990 and 2017, and selected from four databases. All studies included participants of both genders and age between 18 and 50 years, used Functional Magnetic Resonance Imaging (fMRI) and SDMT adaptation and reported brain regions associated with the task. Six of them also reported the region coordinates in a standard space, so they were included in a meta-analysis. Activation Likelihood Estimation algorithm, with significance for p < 0.05 corrected for multiple comparisons, was used to identify areas that are robustly related to the performance of the SDMT. The areas predominantly reported in the studies of our meta-analysis were regions of the frontoparietal attentional network and occipital cortex, as well as cuneus, precuneus, and cerebellum. Individually all regions that survived the statistical threshold are consistent with what is expected after reviewing prospective studies. The present study allowed the identification of brain areas activated during the performance of the SDMT in healthy subjects, and therefore it will help understanding the differences in brain activation by this task in clinical populations. Moreover, it may guide future

  1. Cost analysis of two community-based HIV testing service modalities led by a Non-Governmental Organization in Cape Town, South Africa.

    Science.gov (United States)

    Meehan, Sue-Ann; Beyers, Nulda; Burger, Ronelle

    2017-12-02

    In South Africa, the financing and sustainability of HIV services is a priority. Community-based HIV testing services (CB-HTS) play a vital role in diagnosis and linkage to HIV care for those least likely to utilise government health services. With insufficient estimates of the costs associated with CB-HTS provided by NGOs in South Africa, this cost analysis explored the cost to implement and provide services at two NGO-led CB-HTS modalities and calculated the costs associated with realizing key HIV outputs for each CB-HTS modality. The study took place in a peri-urban area where CB-HTS were provided from a stand-alone centre and mobile service. Using a service provider (NGO) perspective, all inputs were allocated by HTS modality with shared costs apportioned according to client volume or personnel time. We calculated the total cost of each HTS modality and the cost categories (personnel, capital and recurring goods/services) across each HTS modality. Costs were divided into seven pre-determined project components, used to examine cost drivers. HIV outputs were analysed for each HTS modality and the mean cost for each HIV output was calculated per HTS modality. The annual cost of the stand-alone and mobile modalities was $96,616 and $77,764 respectively, with personnel costs accounting for 54% of the total costs at the stand-alone. For project components, overheads and service provision made up the majority of the costs. The mean cost per person tested at stand-alone ($51) was higher than at the mobile ($25). Linkage to care cost at the stand-alone ($1039) was lower than the mobile ($2102). This study provides insight into the cost of an NGO led CB-HTS project providing HIV testing and linkage to care through two CB-HIV testing modalities. The study highlights; (1) the importance of including all applicable costs (including overheads) to ensure an accurate cost estimate that is representative of the full service implementation cost, (2) the direct link between test

  2. Medical Students’ Knowledge of Indications for Imaging Modalities and Cost Analysis of Incorrect Requests, Shiraz, Iran 2011-2012

    Directory of Open Access Journals (Sweden)

    Parisa Islami Parkoohi

    2015-05-01

    Full Text Available Medical imaging has a remarkable role in the practice of clinical medicine. This study intends to evaluate the knowledge of indications of five common medical imaging modalities and estimation of the imposed cost of their non-indicated requests among medical students who attend Shiraz University of Medical Sciences, Shiraz, Iran. We conducted across-sectional survey using a self-administered questionnaire to assess the knowledge of indications of a number of medical imaging modalities among 270 medical students during their externship or internship periods. Knowledge scoring was performed according to a descriptive international grade conversion (fail to excellent using Iranian academic grading (0 to 20. In addition, we estimated the cost for incorrect selection of those modalities according to public and private tariffs in US dollars. The participation and response rate was 200/270 (74%. The mean knowledge score was fair for all modalities. Similar scores were excellent for X-ray, acceptable for Doppler ultrasonography, and fair for ultrasonography, CT scan and MRI. The total cost for non-indicated requests of those modalities equaled $104303 (public tariff and $205581 (private tariff. Medical students at Shiraz University of Medical Sciences lacked favorable knowledge about indications for common medical imaging modalities. The results of this study have shown a significant cost for non-indicated requests of medical imaging. Of note, the present radiology curriculum is in need of a major revision with regards to evidence-based radiology and health economy concerns.

  3. Medical students' knowledge of indications for imaging modalities and cost analysis of incorrect requests, shiraz, iran 2011-2012.

    Science.gov (United States)

    Islami Parkoohi, Parisa; Jalli, Reza; Danaei, Mina; Khajavian, Shiva; Askarian, Mehrdad

    2014-05-01

    Medical imaging has a remarkable role in the practice of clinical medicine. This study intends to evaluate the knowledge of indications of five common medical imaging modalities and estimation of the imposed cost of their non-indicated requests among medical students who attend Shiraz University of Medical Sciences, Shiraz, Iran. We conducted across-sectional survey using a self-administered questionnaire to assess the knowledge of indications of a number of medical imaging modalities among 270 medical students during their externship or internship periods. Knowledge scoring was performed according to a descriptive international grade conversion (fail to excellent) using Iranian academic grading (0 to 20). In addition, we estimated the cost for incorrect selection of those modalities according to public and private tariffs in US dollars. The participation and response rate was 200/270 (74%). The mean knowledge score was fair for all modalities. Similar scores were excellent for X-ray, acceptable for Doppler ultrasonography, and fair for ultrasonography, CT scan and MRI. The total cost for non-indicated requests of those modalities equaled $104303 (public tariff) and $205581 (private tariff). Medical students at Shiraz University of Medical Sciences lacked favorable knowledge about indications for common medical imaging modalities. The results of this study have shown a significant cost for non-indicated requests of medical imaging. Of note, the present radiology curriculum is in need of a major revision with regards to evidence-based radiology and health economy concerns.

  4. Enhancing Friction Stir Weldability of 6061-T6 Al and AZ31B Mg Alloys Assisted by External Non-rotational Shoulder

    Science.gov (United States)

    Ji, Shude; Huang, Ruofei; Meng, Xiangchen; Zhang, Liguo; Huang, Yongxian

    2017-05-01

    In order to increase cooling rate and then reduce the amounts of intermetallic compounds, external non-rotational shoulder tool system derived from traditional tool in friction stir welding was used to join dissimilar Al and Mg alloys. In this study, based on the external non-rotational shoulder, the weldability of Al and Mg alloys was significantly improved. The non-rotational shoulder tool is propitious to make more materials into weld, increase cooling rate and then reduce material adhesion of rotational pin, obtaining sound joint with smaller flashes and smooth surface. Importantly, the thickness of intermetallic compounds layer is reduced compared with traditional tool. Meanwhile, hardness values of dissimilar joint present uneven distribution, resulting from complex intercalated structures in nugget zone (NZ) featured by intermetallic compound layers and fine recrystallized Mg and Al grains. Compared with traditional tool, non-rotational shoulder is beneficial to higher tensile properties of joint. Due to the intermetallic compound layer formed in the interface of Al-Mg, the welding joint easily fractures at the NZ, presenting the typical brittle fracture mode.

  5. CoSMoMVPA: Multi-Modal Multivariate Pattern Analysis of Neuroimaging Data in Matlab/GNU Octave.

    Science.gov (United States)

    Oosterhof, Nikolaas N; Connolly, Andrew C; Haxby, James V

    2016-01-01

    Recent years have seen an increase in the popularity of multivariate pattern (MVP) analysis of functional magnetic resonance (fMRI) data, and, to a much lesser extent, magneto- and electro-encephalography (M/EEG) data. We present CoSMoMVPA, a lightweight MVPA (MVP analysis) toolbox implemented in the intersection of the Matlab and GNU Octave languages, that treats both fMRI and M/EEG data as first-class citizens. CoSMoMVPA supports all state-of-the-art MVP analysis techniques, including searchlight analyses, classification, correlations, representational similarity analysis, and the time generalization method. These can be used to address both data-driven and hypothesis-driven questions about neural organization and representations, both within and across: space, time, frequency bands, neuroimaging modalities, individuals, and species. It uses a uniform data representation of fMRI data in the volume or on the surface, and of M/EEG data at the sensor and source level. Through various external toolboxes, it directly supports reading and writing a variety of fMRI and M/EEG neuroimaging formats, and, where applicable, can convert between them. As a result, it can be integrated readily in existing pipelines and used with existing preprocessed datasets. CoSMoMVPA overloads the traditional volumetric searchlight concept to support neighborhoods for M/EEG and surface-based fMRI data, which supports localization of multivariate effects of interest across space, time, and frequency dimensions. CoSMoMVPA also provides a generalized approach to multiple comparison correction across these dimensions using Threshold-Free Cluster Enhancement with state-of-the-art clustering and permutation techniques. CoSMoMVPA is highly modular and uses abstractions to provide a uniform interface for a variety of MVP measures. Typical analyses require a few lines of code, making it accessible to beginner users. At the same time, expert programmers can easily extend its functionality. Co

  6. Urban Modality

    Directory of Open Access Journals (Sweden)

    Jorge Gil

    2016-02-01

    integrated multimodal network model combines the various mobility infrastructure networks and the buildings’ land use to create a detailed description of the region, using open spatial data and open source Geographic Information Systems (GIS technologies. The network model’s spatial analysis covers local urban form indicators, such as street layout, network density and land use mix, as well as regional indicators of multimodal accessibility and network configuration (its structure, to give a holistic profile of urban areas across modes and scales of travel. The analysis results go through exploratory data mining and classification procedures to identify urban form typologies of urban areas. It is shown that there is a relation between this ‘urban modality’ of urban areas and the travel patterns of their residents, measured as a set of sustainable mobility indicators related to mode share and distance travelled. For this reason, ‘urban modality’ offers the possibility for ex-ante evaluation of sustainable mobility potential of planned urban areas. Furthermore, when combined with the socio-economic profile of the resident population, ‘urban modality’ defines a context for the ex-post evaluation of sustainable mobility performance of existing urban areas. The evaluation of suburban areas together with the more central historical urban areas gives invariably a high score in sustainable travel to the central areas, and rates the suburban areas negatively. On the other hand, the evaluation of sustainable mobility performance in the context of suburban areas of the same type allows the finer distinction of underperformers that have scope for improvement, and overachievers that provide examples of (relative success. This contextual evaluation can become a decision support instrument for “hard” and “soft” planning measures involving sustainable mobility targets. Applying this method to the set of VINEX neighbourhoods of the Randstad leads to the conclusion

  7. Meditations on Metaphysical Modality

    OpenAIRE

    Willis, Edmund Lindsay James

    2011-01-01

    Although metaphysical modality has been much discussed and exploited by philosophers, its precise nature is often left unanalysed and obscure. This dissertation marks an attempt to understand it better. After examining modality in general, the specific topic is introduced through consideration of the views of Kripke and Lewis. Comparisons are then made with logical, scientific and conceptual modalities. Finally, it is argued that metaphysical modality is that variety of modality which is alet...

  8. [Analysis of the therapeutic effects of different treatment modalities on the outcomes of 87 patients with lung oligometastasis from nasopharyngeal carcinoma after radiotherapy].

    Science.gov (United States)

    Tang, Q; Hu, Q Y; Piao, Y F; Hua, Y H; Chen, X Z

    2016-03-23

    The aim of the present study was to evaluate the efficacy of three different modalities in treatment of lung oligometastases from nasopharyngeal carcinoma (NPC) after radiotherapy and to identify a more appropriate treatment modality. The clinical data of 87 cases of lung oligometastases from NPC were analyzed retrospectively. Among them, 33 patients underwent local small-field irradiation+ /- chemotherapy, 28 underwent whole-lung irradiation+ chemotherapy, and 26 underwent simple chemotherapy. The survival rates were calculated using Kaplan-Meier analysis. The differences among the modalities were evaluated using the log-rank test. Cox univariate and multivariate analyses were performed to determine the influencing factors. The 3-year lung metastasis survival (LMS) rates of patients with lung metastasis undergoing the three treatment modalities (local small-field irradiation+ /-chemotherapy, whole-lung irradiation+ chemotherapy and chemotherapy alone) were 89.3%, 72.7%, and 72.4%, respectively, showing a significant difference between the groups (P=0.003). Further subgroup analysis showed that the 5-year LMS rate was significantly higher in the local small-field irradiation+ /-chemotherapy group than that in the whole-lung irradiation+ chemotherapy group and chemotherapy alone group (P=0.001). The 2-year progression-free survival (PFS) rates of the three groups were 57.1%, 25.8% and 3.8%, respectively, showing significant intergroup differences (P=0.002 and P<0.001). Multivariate analysis indicated that compared with the whole lung irradiation group and the chemotherapy alone group, the local irradiation+ /- chemotherapy is an independent favorable prognostic factor for LMS and PFS (P<0.05). Local radiotherapy combined with systemic chemotherapy is the best therapeutic modality for lung oligometastases derived from NPC after radiotherapy, improving the LMS and prolonging the PFS.

  9. Protocol for a systematic review with network meta-analysis of the modalities used to deliver eHealth interventions for chronic pain.

    Science.gov (United States)

    Slattery, Brian W; Haugh, Stephanie; Francis, Kady; O'Connor, Laura; Barrett, Katie; Dwyer, Christopher P; O'Higgins, Siobhan; Egan, Jonathan; McGuire, Brian E

    2017-03-03

    As eHealth interventions prove both efficacious and practical, and as they arguably overcome certain barriers encountered by traditional face-to-face treatment for chronic pain, their number has increased dramatically in recent times. However, there is a dearth of research that focuses on evaluating and comparing the different types of technology-assisted interventions. This is a protocol for a systematic review that aims to evaluate the eHealth modalities in the context of psychological and non-psychological (other than non-drug) interventions for chronic pain. We will search the Cochrane Central Register of Controlled Trials (CENTRAL: The Cochrane Library), MEDLINE, Embase and PsycINFO. Randomised controlled trials (RCTs) with more than 20 participants per trial arm that have evaluated non-drug psychological or non-psychological interventions delivered via an eHealth modality and have pain as an outcome measure will be included. Two review authors will independently extract data and assess the study suitability in accordance with the Cochrane Collaboration Risk of Bias Tool. Studies will be included if they measure at least one outcome variable in accordance with the IMMPACT guidelines (i.e. pain severity, pain interference, physical functioning, symptoms, emotional functioning, global improvement and disposition). Secondary outcomes will be measures of depression and health-related quality of life (HRQoL). A network meta-analysis will be conducted based on direct comparisons to generate indirect comparisons of modalities across treatment trials, which will return rankings for the eHealth modalities in terms of their effectiveness. Most trials that use an eHealth intervention to manage chronic pain typically use one modality. As a result, little evidence exists to support which modality type is the most effective. The current review will address this gap in the literature and compare the different eHealth modalities used for technology-assisted interventions for

  10. Strategies to increase patient safety in haemodialysis: Application of the modal analysis system of errors and effects (FEMA system

    Directory of Open Access Journals (Sweden)

    María Dolores Arenas Jiménez

    2017-11-01

    ón y la hipotensión (42,7 y 27,5% del total de EA registrados, respectivamente. Los EA relacionados con el acceso vascular fueron uno de cada 68,5 tratamientos. Se registraron un total de 21 fallos en la asistencia (1 cada 62 tratamientos, los cuales estaban relacionados con fallos en la aplicación de la técnica y en la administración de la medicación. El mayor número de prioridad de riesgo lo obtuvieron los fallos relacionados con errores en el peso, disfunción o rotura del catéter y salida de agujas. Conclusiones: Las complicaciones en HD son frecuentes y la consideración de algunas de ellas como EA podría mejorar la seguridad en la asistencia, al poner en marcha medidas preventivas. La implementación del sistema AMFE permite estratificar y priorizar los posibles fallos de las unidades de diálisis, y actuar con mayor o menor premura, desarrollando las acciones de mejora necesarias. Keywords: Safety, Haemodialysis, Failure modal and effects analysis systems, Adverse events, Errors, Palabras clave: Seguridad, Hemodiálisis, Sistema de análisis modal de fallos y efectos, Eventos adversos, Errores

  11. Radical Cystectomy Compared to Combined Modality Treatment for Muscle-Invasive Bladder Cancer: A Systematic Review and Meta-Analysis

    International Nuclear Information System (INIS)

    Vashistha, Vishal; Wang, Hanzhang; Mazzone, Andrew; Liss, Michael A.; Svatek, Robert S.; Schleicher, Mary; Kaushik, Dharam

    2017-01-01

    Purpose: To perform a comprehensive comparison of overall survival (OS), disease-specific survival (DSS), progression-free survival (PFS), and treatment-related complications between radical cystectomy (RC) and combined modality treatment (CMT—radiation therapy, concurrent chemotherapy, and maximal transurethral resection of bladder tumor) in the setting of muscle-invasive bladder cancer. Methods and Materials: We searched 7 databases (PubMed, Scopus, EMBASE, Proquest, CINAHL, and (ClinicalTrials.gov)) for randomized, controlled trials and prospective and retrospective studies directly comparing RC with CMT from database inception to March 2016. We conducted meta-analyses evaluating OS, DSS, and PFS with hazard ratios (HRs) and 95% confidence intervals (CIs). Results: Nineteen studies evaluating 12,380 subjects were selected. For the 8 studies encompassing 9554 subjects eligible for meta-analyses, we found no difference in OS at 5 years (HR 0.96, favoring CMT, 95% CI 0.72-1.29; P=.778) or 10 years (HR 1.02, favoring cystectomy, 95% CI 0.73-1.42; P=.905). No difference was observed in DSS at 5 years (HR 0.83, favoring radiation, 95% CI 0.54-1.28; P=.390) or 10 years (HR 1.17, favoring cystectomy, 95% CI 0.89-1.55; P=.264), or PFS at 10 years (HR 0.85, favoring CMT, 95% CI 0.43-1.67; P=.639). The cystectomy arms had higher rates of early major complications, whereas rates of minor complications were similar between the 2 treatments. Conclusion: Current meta-analysis reveals no differences in OS, DSS, or PFS between RC and CMT. Further randomized, controlled trials are necessary to identify the optimal treatment for specific patients.

  12. Radical Cystectomy Compared to Combined Modality Treatment for Muscle-Invasive Bladder Cancer: A Systematic Review and Meta-Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vashistha, Vishal [Department of Internal Medicine, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Wang, Hanzhang [Department of Urology, University of Texas Health Science Center at San Antonio, San Antonio, Texas (United States); Mazzone, Andrew [Rush Medical College, Rush University Medical Center, Chicago, Illinois (United States); Liss, Michael A.; Svatek, Robert S. [Department of Urology, University of Texas Health Science Center at San Antonio, San Antonio, Texas (United States); Schleicher, Mary [Department of Internal Medicine, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Kaushik, Dharam, E-mail: Kaushik@uthscsa.edu [Department of Urology, University of Texas Health Science Center at San Antonio, San Antonio, Texas (United States)

    2017-04-01

    Purpose: To perform a comprehensive comparison of overall survival (OS), disease-specific survival (DSS), progression-free survival (PFS), and treatment-related complications between radical cystectomy (RC) and combined modality treatment (CMT—radiation therapy, concurrent chemotherapy, and maximal transurethral resection of bladder tumor) in the setting of muscle-invasive bladder cancer. Methods and Materials: We searched 7 databases (PubMed, Scopus, EMBASE, Proquest, CINAHL, and (ClinicalTrials.gov)) for randomized, controlled trials and prospective and retrospective studies directly comparing RC with CMT from database inception to March 2016. We conducted meta-analyses evaluating OS, DSS, and PFS with hazard ratios (HRs) and 95% confidence intervals (CIs). Results: Nineteen studies evaluating 12,380 subjects were selected. For the 8 studies encompassing 9554 subjects eligible for meta-analyses, we found no difference in OS at 5 years (HR 0.96, favoring CMT, 95% CI 0.72-1.29; P=.778) or 10 years (HR 1.02, favoring cystectomy, 95% CI 0.73-1.42; P=.905). No difference was observed in DSS at 5 years (HR 0.83, favoring radiation, 95% CI 0.54-1.28; P=.390) or 10 years (HR 1.17, favoring cystectomy, 95% CI 0.89-1.55; P=.264), or PFS at 10 years (HR 0.85, favoring CMT, 95% CI 0.43-1.67; P=.639). The cystectomy arms had higher rates of early major complications, whereas rates of minor complications were similar between the 2 treatments. Conclusion: Current meta-analysis reveals no differences in OS, DSS, or PFS between RC and CMT. Further randomized, controlled trials are necessary to identify the optimal treatment for specific patients.

  13. The contextual and modal character of quantum mechanics : a formal and philosophical analysis in the foundations of physics

    NARCIS (Netherlands)

    Ronde, C. de

    2011-01-01

    This doctoral dissertation contains four main elements: 1. We put forward an interpretational map of quantum mechanics in general and of the modal interpretation in particular based on metaphysical and anti-metaphysical stances. 2. In contraposition to what we characterize as the

  14. Modal Logics and Definability

    OpenAIRE

    Kuusisto, Antti

    2013-01-01

    In recent years, research into the mathematical foundations of modal logic has become increasingly popular. One of the main reasons for this is the fact that modal logic seems to adapt well to the requirements of a wide range of different fields of application. This paper is a summary of some of the author’s contributions to the understanding of modal definability theory.

  15. Histopathology in 3D: From three-dimensional reconstruction to multi-stain and multi-modal analysis

    Directory of Open Access Journals (Sweden)

    Derek Magee

    2015-01-01

    Full Text Available Light microscopy applied to the domain of histopathology has traditionally been a two-dimensional imaging modality. Several authors, including the authors of this work, have extended the use of digital microscopy to three dimensions by stacking digital images of serial sections using image-based registration. In this paper, we give an overview of our approach, and of extensions to the approach to register multi-modal data sets such as sets of interleaved histopathology sections with different stains, and sets of histopathology images to radiology volumes with very different appearance. Our approach involves transforming dissimilar images into a multi-channel representation derived from co-occurrence statistics between roughly aligned images.

  16. Determination of 2D equivalent angles of attack for a non-rotating wind turbine rotor blade

    Energy Technology Data Exchange (ETDEWEB)

    Maassen, W.H.

    1993-11-01

    For the investigation into models to compute the title subject use has been made of the Lanchester-Prandtl lifting line model. The inflow conditions are given by a uniform inflow velocity and the geometrical angles of attack at every spanwise position. A model using pressure measurements at the instrumented sections and a model using 2-dimensional C{sub L}-{alpha} data at certain spanwise positions were investigated. In section two the experimental setups of the experiments at ECN (Netherlands Energy Research Foundation) and FFA (the Aeronautical Research Institute of Sweden) are presented. In section three the theoretical background and the different methods to compute the 2D equivalent angles of attack are outlined. In section four the results of the computations of the downwash and the 2D equivalent angles of attack for the considered FFA wind tunnel experiment is presented. Finally, in section five the most important conclusions are summarized and a recommendation for the computation of the 2D equivalent angles of attack for the non-rotating blade experiments at ECN is formulated. 59 figs., 2 tabs., 3 appendices, 30 refs.

  17. Comparison of CFD simulations to non-rotating MEXICO blades experiment in the LTT wind tunnel of TUDelft

    International Nuclear Information System (INIS)

    Zhang, Ye; Van Zuijlen, Alexander; Van Bussel, Gerard

    2014-01-01

    In this paper, three dimensional flow over non-rotating MEXICO blades is simulated by CFD methods. The numerical results are compared with the latest MEXICO wind turbine blades measurements obtained in the low speed low turbulence (LTT) wind tunnel of Delft University of Technology. This study aims to validate CFD codes by using these experimental data measured in well controlled conditions. In order to avoid use of wind tunnel corrections, both the blades and the wind tunnel test section are modelled in the simulations. The ability of Menter's k – ω shear stress transport (SST) turbulence model is investigated at both attached flow and massively separated flow cases. Steady state Reynolds averaged Navier Stokes (RANS) equations are solved in these computations. The pressure distribution at three measured sections are compared under the conditions of different inflow velocities and a range of angles of attack. The comparison shows that at attached flow condition, good agreement can be obtained for all three airfoil sections. Even with massively separated flow, still fairly good pressure distribution comparison can be found for the DU and NACA airfoil sections, although the RISØ section shows poor comparison. At the near stall case, considerable deviations exists on the forward half part of the upper surface for all three sections

  18. Establishment study of the in vivo imaging analysis with small animal imaging modalities for bio-durg development

    International Nuclear Information System (INIS)

    Jang, Beomsu; Park, Sanghyeon; Choi, Dae Seong; Park, Jeonghoon; Jung, Uhee; Lee, Yun Jong

    2012-01-01

    In this study, we established the image modalities (micro-PET, SPECT/CT) using the experimental animal (mouse) for the development of imaging assessment method for the bio-durg and extramural collaboration proposal. We examined the micro-SPECT/CT, PET imaging study using the Siemens Inveon micro-multimodality system (SPECT/CT) and imaging study using the Siemens Inveon micro-multimodality system (SPECT/CT) and micro-PET with 99m Tc tricarbonyl bifunctional chelators and 18 F-clotrimazole derivative. SPECT imaging studies were performed with 99m Tc tricarbonyl BFCs. PET imaging study was performed with 18 F-clotrimazole derivatives. We performed the PET image study of 18 F-clotrimazole derivatives using U87MG tumor bearing mice. Also we tested the intramural and extramural collaboration using small animal imaging modalities and prepared the draft of extramural R and D operation manual for small animal imaging modalities and the experimental animal imaging facility. These research results can be utilized as a basic image study protocols and data for the image assessment of drugs including biological drug

  19. Implementation of the Scanning Laser Doppler Vibrometer Combined with a Light-Weight Pneumatic Artificial Muscle Actuator for the Modal Analysis of a Civil Structure

    Directory of Open Access Journals (Sweden)

    K. Deckers

    2012-01-01

    Full Text Available The identification of the modal parameters of bridges and other large civil constructions has become an important research issue. Different approaches have been proposed depending on the excitation used: ambient excitations (due to wind, traffic, … or artificial excitations (e.g. impact test with heavy drop weights. In practice it turns out that not all modes are well excited by the ambient forces. Hence the application of an artificial actuator is advisable. The problem is that larger constructions often require large and heavy excitation devices, which are hard to manipulate. Another difficulty encountered in performing a modal analysis on large civil constructions is the necessity for a large number of high sensitivity sensors. Consequently a large number of cables has to be installed resulting in a large setup time.

  20. PageRank versatility analysis of multilayer modality-based network for exploring the evolution of oil-water slug flow.

    Science.gov (United States)

    Gao, Zhong-Ke; Dang, Wei-Dong; Li, Shan; Yang, Yu-Xuan; Wang, Hong-Tao; Sheng, Jing-Ran; Wang, Xiao-Fan

    2017-07-14

    Numerous irregular flow structures exist in the complicated multiphase flow and result in lots of disparate spatial dynamical flow behaviors. The vertical oil-water slug flow continually attracts plenty of research interests on account of its significant importance. Based on the spatial transient flow information acquired through our designed double-layer distributed-sector conductance sensor, we construct multilayer modality-based network to encode the intricate spatial flow behavior. Particularly, we calculate the PageRank versatility and multilayer weighted clustering coefficient to quantitatively explore the inferred multilayer modality-based networks. Our analysis allows characterizing the complicated evolution of oil-water slug flow, from the opening formation of oil slugs, to the succedent inter-collision and coalescence among oil slugs, and then to the dispersed oil bubbles. These properties render our developed method particularly powerful for mining the essential flow features from the multilayer sensor measurements.

  1. Multi-modal MRI analysis with disease-specific spatial filtering: initial testing to predict mild cognitive impairment patients who convert to Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Kenichi eOishi

    2011-08-01

    Full Text Available Background: Alterations of the gray and white matter have been identified in Alzheimer’s disease (AD by structural MRI and diffusion tensor imaging (DTI. However, whether the combination of these modalities could increase the diagnostic performance is unknown.Methods: Participants included 19 AD patients, 22 amnestic mild cognitive impairment (aMCI patients, and 22 cognitively normal elderly (NC. The aMCI group was further divided into an aMCI-converter group (converted to AD dementia within three years, and an aMCI-stable group who did not convert in this time period. A T1-weighted image, a T2 map, and a DTI of each participant were normalized, and voxel-based comparisons between AD and NC groups were performed. Regions-of-interest, which defined the areas with significant differences between AD and NC, were created for each modality and named disease-specific spatial filters (DSF. Linear discriminant analysis was used to optimize the combination of multiple MRI measurements extracted by DSF to effectively differentiate AD from NC. The resultant DSF and the discriminant function were applied to the aMCI group to investigate the power to differentiate the aMCI-converters from the aMCI-stable patients. Results: The multi-modal approach with AD-specific filters led to a predictive model with an area under the receiver operating characteristic curve (AUC of 0.93, in differentiating aMCI-converters from aMCI-stable patients. This AUC was better than that of a single-contrast-based approach, such as T1-based morphometry or diffusion anisotropy analysis. Conclusion: The multi-modal approach has the potential to increase the value of MRI in predicting conversion from aMCI to AD.

  2. The Modal Dimension

    Directory of Open Access Journals (Sweden)

    Giluano Torrengo

    2018-05-01

    Full Text Available Space and time are two obvious candidates as dimensions of reality. Yet, are they the only two dimensions of reality? Famously, David Lewis maintained the doctrine of ―modal realism‖, the thesis that possible worlds exist and are entities as concrete as the actual world that we live in. In this paper, I will explore the idea that modality can be construed as a dimension along with space and time. However, although Lewis‘ modal realism is the main source of inspiration for this construal of modality, I will argue that something else is required for having a modal dimension.

  3. Aplicación del análisis modal de fallos y efectos en el proceso de donación de sangre total Application of modal analysis of failures and effects in the process of total blood donation

    Directory of Open Access Journals (Sweden)

    Tatiana Escoriza-Martínez

    2010-12-01

    Full Text Available La búsqueda constante de medidas para garantizar la calidad y seguridad de la sangre y hemocomponentes constituye una necesidad para el logro de la seguridad transfusional. Aunque las buenas prácticas de producción tienen el objetivo de disminuir los riesgos para obtener productos puros, seguros y eficaces, es necesario complementarlas con herramientas que permitan prevenir los posibles fallos y detectar dichos riesgos. Tal es el caso de la aplicación del Análisis Modal de Fallos y Efectos en el Banco de Sangre Provincial de Villa Clara, donde se identificaron y evaluaron las posibles fallas del proceso de donación de sangre total, lo que permitió caracterizar este proceso, identificar sus variables críticas, proporcionar las bases para proponer nuevos puntos críticos de control y establecer las acciones necesarias para la reducción o eliminación de las fallas detectadas. Esto contribuyó al aumento de la satisfacción de los servicios de transfusión hospitalarios y de los pacientes.The constant search of measures to guarantee the quality and the safe of blood and hemocomponents is a need to achieve the transfusion safe. Although the aim of the good practices of production was to decrease the risks to obtain pure, safe and effective products, it is necessary its fulfillment with tools allowing to prevent the potential failures and to detect such risks. That is the case of the application of the Modal Analysis of Failures and Effects in the Provincial Blood Bank of Villa Clara where the potential failures in the process of total blood donation were identified and assessed, allowing to characterize it, to identify its critical variables, to lay the foundations to propose new critical points of control and to establish the actions necessary to reduce or to eliminate the failures detected. All this contributed to the satisfaction of hospital transfusion services and of patients.

  4. Study of causal relationships among indicators of academic performance in the freshman year of Computer Science by using modal implicative analysis

    Directory of Open Access Journals (Sweden)

    Larisa Zamora-Matamoros

    2018-03-01

    Full Text Available The Statistical Implicative Analysis (SIA is a method of non-symmetrical analysis of data whose main objective is the structuring of data, interrelating individuals and variables, the extraction of inductive rules among the variables and from their contingency, the explanation and in consequence a certain prediction in different knowledge branches. The SIA holds two techniques of analysis of data, the cohesive analysis and the implicative analysis, along with the classificatory or similarity analysis. The objective of the present research is to reveal possible similarity, propensity and cohesion relationships among the academic results of students coming from high schools that enter to Computer Science career and the results that they show in undergraduate courses related to Mathematics and Programming, which they receive in the first year of the mentioned career. The gathered data were processed using the software SIASI for modal data.

  5. 6 DOF articulated-arm robot and mobile platform: Dynamic modelling as Multibody System and its validation via Experimental Modal Analysis.

    Science.gov (United States)

    Toledo Fuentes, A.; Kipfmueller, M.; José Prieto, M. A.

    2017-10-01

    Mobile manipulators are becoming a key instrument to increase the flexibility in industrial processes. Some of their requirements include handling of objects with different weights and sizes and their “fast” transportation, without jeopardizing production workers and machines. The compensation of forces affecting the system dynamic is therefore needed to avoid unwanted oscillations and tilting by sudden accelerations and decelerations. One general solution may be the implementation of external positioning elements to active stabilize the system. To accomplish the approach, the dynamic behavior of a robotic arm and a mobile platform was investigated to develop the stabilization mechanism using multibody simulations. The methodology used was divided into two phases for each subsystem: their natural frequencies and modal shapes were obtained using experimental modal analyses. Then, based on these experimental results, multibody simulation models (MBS) were set up and its dynamical parameters adjusted. Their modal shapes together with their obtained natural frequencies allowed a quantitative and qualitative analysis. In summary, the MBS models were successfully validated with the real subsystems, with a maximal percentage error of 15%. These models will serve as the basis for future steps in the design of the external actuators and its control strategy using a co-simulation tool.

  6. Modal Testing of Mechanical Structures subject to Operational Excitation Forces

    DEFF Research Database (Denmark)

    Møller, N.; Brincker, Rune; Herlufsen, H.

    2001-01-01

    Operational Modal Analysis also known as Output Only Modal Analysis has in the recent years been used for extracting modal parameters of civil engineering structures and is now becoming popular for mechanical structures. The advantage of the method is that no artificial excitation need to be appl......Operational Modal Analysis also known as Output Only Modal Analysis has in the recent years been used for extracting modal parameters of civil engineering structures and is now becoming popular for mechanical structures. The advantage of the method is that no artificial excitation need...

  7. Numerical Simulation of Non-Rotating and Rotating Coolant Channel Flow Fields. Part 1

    Science.gov (United States)

    Rigby, David L.

    2000-01-01

    Future generations of ultra high bypass-ratio jet engines will require far higher pressure ratios and operating temperatures than those of current engines. For the foreseeable future, engine materials will not be able to withstand the high temperatures without some form of cooling. In particular the turbine blades, which are under high thermal as well as mechanical loads, must be cooled. Cooling of turbine blades is achieved by bleeding air from the compressor stage of the engine through complicated internal passages in the turbine blades (internal cooling, including jet-impingement cooling) and by bleeding small amounts of air into the boundary layer of the external flow through small discrete holes on the surface of the blade (film cooling and transpiration cooling). The cooling must be done using a minimum amount of air or any increases in efficiency gained through higher operating temperature will be lost due to added load on the compressor stage. Turbine cooling schemes have traditionally been based on extensive empirical data bases, quasi-one-dimensional computational fluid dynamics (CFD) analysis, and trial and error. With improved capabilities of CFD, these traditional methods can be augmented by full three-dimensional simulations of the coolant flow to predict in detail the heat transfer and metal temperatures. Several aspects of turbine coolant flows make such application of CFD difficult, thus a highly effective CFD methodology must be used. First, high resolution of the flow field is required to attain the needed accuracy for heat transfer predictions, making highly efficient flow solvers essential for such computations. Second, the geometries of the flow passages are complicated but must be modeled accurately in order to capture all important details of the flow. This makes grid generation and grid quality important issues. Finally, since coolant flows are turbulent and separated the effects of turbulence must be modeled with a low Reynolds number

  8. FY 1998 annual summary report on 6-axis, high-precision non-rotating machining systems (first year); 1998 nendo 6 jiku koseido heru kako system no kaihatsu seika hokokusho. Daiichinendo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This R and D program is aimed at development of high-precision systems, based on non-rotating machining, in order to improve precision of machining of curved surfaces, e.g., mold, and members of complex shapes, e.g., those for aircraft. For non-rotating machining of curved surfaces, it is necessary to continuously control attitude and sending speed of the tool, and hence to simultaneously control 6 axes of a high-speed, high-precision tool machine. New techniques, e.g., high-precision non-rotating machining, 6-axis CAM/CAE systems and high-speed, high-precision NC systems, are being developed, in order to realize the above objectives. The total systems combining these techniques are also being developed. The 6-axis, high-precision, non-rotating tool machine will be made on a trial basis, to demonstrate its practicality. The major FY 1998 results are development of a non-rotating machining tool for deep grooves (under the theme of machining techniques), development of software for cutter path generation for 6-axis non-rotating machining to confirm its validity by the tests with a commercial machine (CAD/CAM), and modification of NC for early-stage cutting tests (NC). (NEDO)

  9. Advances in Modal Logic

    DEFF Research Database (Denmark)

    Modal logic is a subject with ancient roots in the western logical tradition. Up until the last few generations, it was pursued mainly as a branch of philosophy. But in recent years, the subject has taken new directions with connections to topics in computer science and mathematics. This volume...... is the proceedings of the conference of record in its fi eld, Advances in Modal Logic. Its contributions are state-of-the-art papers. The topics include decidability and complexity results for specifi c modal logics, proof theory of modal logic, logics for reasoning about time and space, provability logic, dynamic...... epistemic logic, and the logic of evidence....

  10. National Cancer Data Base Analysis of Radiation Therapy Consolidation Modality for Cervical Cancer: The Impact of New Technological Advancements

    Energy Technology Data Exchange (ETDEWEB)

    Gill, Beant S. [Department of Radiation Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Lin, Jeff F. [Department of Gynecologic Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Krivak, Thomas C. [Department of Gynecologic Oncology, Western Pennsylvania Hospital, Pittsburgh, Pennsylvania (United States); Sukumvanich, Paniti; Laskey, Robin A.; Ross, Malcolm S.; Lesnock, Jamie L. [Department of Gynecologic Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Beriwal, Sushil, E-mail: beriwals@upmc.edu [Department of Radiation Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States)

    2014-12-01

    Purpose: To utilize the National Cancer Data Base to evaluate trends in brachytherapy and alternative radiation therapy utilization in the treatment of cervical cancer, to identify associations with outcomes between the various radiation therapy modalities. Methods and Materials: Patients with International Federation of Gynecology and Obstetrics stage IIB-IVA cervical cancer in the National Cancer Data Base who received treatment from January 2004 to December 2011 were analyzed. Overall survival was estimated by the Kaplan-Meier method. Univariate and multivariable analyses were performed to identify factors associated with type of boost radiation modality used and its impact on survival. Results: A total of 7654 patients had information regarding boost modality. A predominant proportion of patients were Caucasian (76.2%), had stage IIIB (48.9%) disease with squamous (82.0%) histology, were treated at academic/research centers (47.7%) in the South (34.8%), and lived 0 to 5 miles (27.9%) from the treating facility. A majority received brachytherapy (90.3%). From 2004 to 2011, brachytherapy use decreased from 96.7% to 86.1%, whereas intensity modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT) use increased from 3.3% to 13.9% in the same period (P<.01). Factors associated with decreased brachytherapy utilization included older age, stage IVA disease, smaller tumor size, later year of diagnosis, lower-volume treatment centers, and facility type. After controlling for significant factors from survival analyses, IMRT or SBRT boost resulted in inferior overall survival (hazard ratio, 1.86; 95% confidence interval, 1.35-2.55; P<.01) as compared with brachytherapy. In fact, the survival detriment associated with IMRT or SBRT boost was stronger than that associated with excluding chemotherapy (hazard ratio, 1.61′ 95% confidence interval, 1.27-2.04′ P<.01). Conclusions: Consolidation brachytherapy is a critical treatment component for

  11. Finite element analysis of high modal dynamic responses of a composite floor subjected to human motion under passive live load

    Directory of Open Access Journals (Sweden)

    Arash Behnia

    Full Text Available Light weight and long span composite floors are common place in modern construction. A critical consequence of this application is undesired vibration which may cause excessive discomfort to occupants. This work investigates the composite floor vibration behavior of an existing building based on a comprehensive study of high modal dynamic responses, the range of which has been absent in previous studies and major analytical templates, of different panels under the influence of loads induced by human motion. The resulting fundamental natural frequency and vibration modes are first validated with respect to experimental and numerical evidences from literature. Departing from close correlation established in comparison, this study explores in detail the effects of intensity of passive live load as additional stationary mass due to crowd jumping as well as considering human structure interaction. From observation, a new approach in the simulation of passive live load through the consideration of human structure interaction and human body characteristics is proposed. It is concluded that higher vibration modes are essential to determine the minimum required modes and mass participation ratio in the case of vertical vibration. The results indicate the need to consider 30 modes of vibration to obtain all possible important excitations and thereby making third harmonic of load frequency available to excite the critical modes. In addition, presence of different intensities of passive live load on the composite floor showed completely different behavior in each particular panel associated with load location of panel and passive live load intensity. Furthermore, implementing human body characteristics in simulation causes an obvious increase in modal damping and hence better practicality and economical presentation can be achieved in structural dynamic behavior.

  12. Modal logics are coalgebraic

    NARCIS (Netherlands)

    Cirstea, C.; Kurz, A.; Pattinson, D.; Schröder, L.; Venema, Y.

    2011-01-01

    Applications of modal logics are abundant in computer science, and a large number of structurally different modal logics have been successfully employed in a diverse spectrum of application contexts. Coalgebraic semantics, on the other hand, provides a uniform and encompassing view on the large

  13. Emplacement processes of tuffaceous sandstones at IODP Site C0011B, Nankai Trough, derived from modal analysis

    Science.gov (United States)

    Schindlbeck, J. C.; Kutterolf, S.; Freundt, A.

    2011-12-01

    Tuffaceous sandstones are characterized by their high amount (25 to 75%) of pyroclasts in their modal composition. During IODP Expedition 322 three interbeds of tuffaceous sandstones have been found within a moderately lithified and bioturbated silty claystone sequence in the late Miocene (>7.07 to ~9.0 Ma) upper part of the middle Shikoku Basin facies. Of the three sandstones, units 1 and 2 are single beds whereas unit 3 is composed of three beds. Modal analyses of 29 sandstone thin sections reveal systematic vertical changes within each bed. Generally low-density pyroclasts are enriched at the top (50-60 vol%) of each sandstone bed whereas dense lithic components (25-30 vol%) and minerals (25-30 vol%) are enriched at the bottom. The vertically varying abundance of various types of lithic fragments (sedimentary, volcanoclastic and metamorphic) suggests that these have also been segregated according to their respective densities. The highest amount of fine-grained matrix glass is found in the middle of each bed. Pumice and lithic fragments in the middle and upper parts of the sandstone beds carry ash coatings. For sandstone package 3, in contrast to 1 and 2, core pictures and thin section analyses indicate a subdivision in three units showing the same significant variations in top to bottom enrichment. This suggests three sedimentation events following each other in short time intervals. Glass and mineral chemistry of each sandstone bed show no significant vertical variations. Specifically the matrix glass-shard major element compositions are identical to the pumice clast composition in each tuffaceous sandstone bed. The compositions of amphibole and pyroxene crystals differ only slightly between the sandstone packages. Application of the Ridolfi et al. (2009) thermobarometric calculations to amphiboles of sandstone packages 1 and 2 suggests that each of these was derived from a volcanic system comprising both a deep and a shallow magma reservoir. Thickness and

  14. Modal analysis of wake fields and its application to elliptical pill-box cavity with finite aperture

    International Nuclear Information System (INIS)

    Kim, S.H.; Chen, K.W.; Yang, J.S.

    1990-01-01

    The potential of the wake-field produced by a bunch of relativistic charged particles passing through a pill-box cavity is expressed by using Floquet's theorem, and an obvious requirement that the energy gain over all acceleration cavity of many pill boxes must be proportional to the number of pill boxes, based on the previous modal approach (BWW theory). It is found that the wake-field is consisted of two classes of modes: the longitudinal modes which are independent of the aperture and the pill-box gap, the hybrid (pill-box) modes which are dependent of the pill-box gap. The wake field is predominated by the fundamental longitudinal mode whose wavelength is on the order of the effective diameter of the cavity, and its magnitude is inversely proportional to the cross sectional area of the cavity for practical cavities with small apertures. Both longitudinal and transverse wake fields due to the longitudinal modes in an elliptical pill box cavity are expressed analytically in a closed series form by solving exactly the longitudinal eigenmode equation in the elliptical cylindrical coordinates in terms of Mathieu functions. It is found that both longitudinal and transverse wake fields whose amplitudes per driving charge are greater than 100 MV/m/μC can be generated in an elliptical cavity

  15. Modal Analysis of 27 mm Piezo Electric Plate for Small-Scale Underwater Sonar-Based Navigation

    Directory of Open Access Journals (Sweden)

    M. O. Afolayan

    2013-01-01

    Full Text Available This work presents progress towards the development of a small-scale, purely sonar-based navigation device for a robotic fish (~394 mm long. Aperture overloading of small (5 mm diameter ultrasonic transmitters does not allow them to be used effectively inside water. A test on a 27 mm diameter buzzer piezo plate shows promising performance under water at frequencies from 4.5 kHz to 80 kHz. ANSYS-based simulation was therefore used to find modal frequencies at higher frequencies so as to optimize this encouraging result. The simulation process also discovered several antiresonant frequencies such as 38.5 kHz, 54 kHz, and 57.5 kHz. All frequencies above the 8th harmonic (10,589.02 Hz are out of phase with the input load except a resonance frequency of 42.5 kHz and an antiresonance frequency of 56.5 kHz. Also, the first harmonic (1,648.73 Hz is the only frequency that gave a nodal deformation.

  16. Statistical analysis of modal properties of a cable-stayed bridge through long-term structural health monitoring with wireless smart sensor networks

    Science.gov (United States)

    Asadollahi, Parisa; Li, Jian

    2016-04-01

    Understanding the dynamic behavior of complex structures such as long-span bridges requires dense deployment of sensors. Traditional wired sensor systems are generally expensive and time-consuming to install due to cabling. With wireless communication and on-board computation capabilities, wireless smart sensor networks have the advantages of being low cost, easy to deploy and maintain and therefore facilitate dense instrumentation for structural health monitoring. A long-term monitoring project was recently carried out for a cable-stayed bridge in South Korea with a dense array of 113 smart sensors, which feature the world's largest wireless smart sensor network for civil structural monitoring. This paper presents a comprehensive statistical analysis of the modal properties including natural frequencies, damping ratios and mode shapes of the monitored cable-stayed bridge. Data analyzed in this paper is composed of structural vibration signals monitored during a 12-month period under ambient excitations. The correlation between environmental temperature and the modal frequencies is also investigated. The results showed the long-term statistical structural behavior of the bridge, which serves as the basis for Bayesian statistical updating for the numerical model.

  17. Documentation for assessment of modal pushover-based scaling procedure for nonlinear response history analysis of "ordinary standard" bridges

    Science.gov (United States)

    Kalkan, Erol; Kwong, Neal S.

    2010-01-01

    The earthquake engineering profession is increasingly utilizing nonlinear response history analyses (RHA) to evaluate seismic performance of existing structures and proposed designs of new structures. One of the main ingredients of nonlinear RHA is a set of ground-motion records representing the expected hazard environment for the structure. When recorded motions do not exist (as is the case for the central United States), or when high-intensity records are needed (as is the case for San Francisco and Los Angeles), ground motions from other tectonically similar regions need to be selected and scaled. The modal-pushover-based scaling (MPS) procedure recently was developed to determine scale factors for a small number of records, such that the scaled records provide accurate and efficient estimates of 'true' median structural responses. The adjective 'accurate' refers to the discrepancy between the benchmark responses and those computed from the MPS procedure. The adjective 'efficient' refers to the record-to-record variability of responses. Herein, the accuracy and efficiency of the MPS procedure are evaluated by applying it to four types of existing 'ordinary standard' bridges typical of reinforced-concrete bridge construction in California. These bridges are the single-bent overpass, multi span bridge, curved-bridge, and skew-bridge. As compared to benchmark analyses of unscaled records using a larger catalog of ground motions, it is demonstrated that the MPS procedure provided an accurate estimate of the engineering demand parameters (EDPs) accompanied by significantly reduced record-to-record variability of the responses. Thus, the MPS procedure is a useful tool for scaling ground motions as input to nonlinear RHAs of 'ordinary standard' bridges.

  18. Assessment of modal-pushover-based scaling procedure for nonlinear response history analysis of ordinary standard bridges

    Science.gov (United States)

    Kalkan, E.; Kwong, N.

    2012-01-01

    The earthquake engineering profession is increasingly utilizing nonlinear response history analyses (RHA) to evaluate seismic performance of existing structures and proposed designs of new structures. One of the main ingredients of nonlinear RHA is a set of ground motion records representing the expected hazard environment for the structure. When recorded motions do not exist (as is the case in the central United States) or when high-intensity records are needed (as is the case in San Francisco and Los Angeles), ground motions from other tectonically similar regions need to be selected and scaled. The modal-pushover-based scaling (MPS) procedure was recently developed to determine scale factors for a small number of records such that the scaled records provide accurate and efficient estimates of “true” median structural responses. The adjective “accurate” refers to the discrepancy between the benchmark responses and those computed from the MPS procedure. The adjective “efficient” refers to the record-to-record variability of responses. In this paper, the accuracy and efficiency of the MPS procedure are evaluated by applying it to four types of existing Ordinary Standard bridges typical of reinforced concrete bridge construction in California. These bridges are the single-bent overpass, multi-span bridge, curved bridge, and skew bridge. As compared with benchmark analyses of unscaled records using a larger catalog of ground motions, it is demonstrated that the MPS procedure provided an accurate estimate of the engineering demand parameters (EDPs) accompanied by significantly reduced record-to-record variability of the EDPs. Thus, it is a useful tool for scaling ground motions as input to nonlinear RHAs of Ordinary Standard bridges.

  19. Antiangiogenic agents in the treatment of recurrent or newly diagnosed glioblastoma: Analysis of single-agent and combined modality approaches

    International Nuclear Information System (INIS)

    Beal, Kathryn; Abrey, Lauren E; Gutin, Philip H

    2011-01-01

    Surgical resection followed by radiotherapy and temozolomide in newly diagnosed glioblastoma can prolong survival, but it is not curative. For patients with disease progression after frontline therapy, there is no standard of care, although further surgery, chemotherapy, and radiotherapy may be used. Antiangiogenic therapies may be appropriate for treating glioblastomas because angiogenesis is critical to tumor growth. In a large, noncomparative phase II trial, bevacizumab was evaluated alone and with irinotecan in patients with recurrent glioblastoma; combination treatment was associated with an estimated 6-month progression-free survival (PFS) rate of 50.3%, a median overall survival of 8.9 months, and a response rate of 37.8%. Single-agent bevacizumab also exceeded the predetermined threshold of activity for salvage chemotherapy (6-month PFS rate, 15%), achieving a 6-month PFS rate of 42.6% (p < 0.0001). On the basis of these results and those from another phase II trial, the US Food and Drug Administration granted accelerated approval of single-agent bevacizumab for the treatment of glioblastoma that has progressed following prior therapy. Potential antiangiogenic agents-such as cilengitide and XL184-also show evidence of single-agent activity in recurrent glioblastoma. Moreover, the use of antiangiogenic agents with radiation at disease progression may improve the therapeutic ratio of single-modality approaches. Overall, these agents appear to be well tolerated, with adverse event profiles similar to those reported in studies of other solid tumors. Further research is needed to determine the role of antiangiogenic therapy in frontline treatment and to identify the optimal schedule and partnering agents for use in combination therapy

  20. Normal modal preferential consequence

    CSIR Research Space (South Africa)

    Britz, K

    2012-12-01

    Full Text Available beyond the basic (propositional) KLM postulates, thereby making use of the additional expressivity provided by modal logic. In particular, we show that the additional constraints we impose on the preferential semantics ensure that the rule...

  1. NIF Periscope Wall Modal Study Comparison of Results for 2 FEA Models with 2 Modal Tests

    International Nuclear Information System (INIS)

    Eli, M W; Gerhard, M A; Lee, C L; Sommer, S C; Woehrle, T G

    2000-01-01

    This report summarizes experimentally and numerically determined modal properties for one of the reinforced concrete end walls of the NIF Periscope Support Structure in Laser Bay 1. Two methods were used to determine these modal properties: (1) Computational finite-element analyses (modal extraction process); and (2) Experimental modal analysis based on measured test data. This report also includes experimentally determined modal properties for a prototype LM3/Polarizer line-replaceable unit (LRU) and a prototype PEPC LRU. Two important parameters, used during the design phase, are validated through testing [ref 1]. These parameters are the natural frequencies and modal damping (of the system in question) for the first several global modes of vibration. Experimental modal testing provides these modal values, along with the corresponding mode shapes. Another important parameter, the input excitation (expected during normal operation of the NIF laser system) [ref 1], can be verified by performing a series of ambient vibration measurements in the vicinity of the particular system (or subsystem) of interest. The topic of ambient input excitation will be covered in a separate report. Due to the large mass of the Periscope Pedestal, it is difficult to excite the entire series of Periscope Pedestal Walls all at once. It was decided that the experimental modal tests would be performed on just one Periscope End Wall in Laser Bay 1. Experimental modal properties for the Periscope End Wall have been used to validate and update the FE analyses. Results from the analyses and modal tests support the conclusion that the Periscope Pedestal will not exceed the stability budget, which is described in reference 1. The results of the modal tests for the Periscope End Wall in Laser Bay 1 have provided examples of modal properties that can be derived from future modal tests of the entire Periscope Assembly (excluding the LRU's). This next series of larger modal tests can be performed

  2. Modal Testing of Mechanical Structures Subject to Operational Excitation Forces

    DEFF Research Database (Denmark)

    Møller, N.; Brincker, Rune; Herlufsen, H.

    2000-01-01

    to the Operational Modal Analysis. For Operational Modal Analysis two different estimation techniques are used: a non-parametric technique based on Frequency Domain Decomposition (FDD), and a parametric technique working on the raw data in time domain, a data driven Stochastic Subspace Identification (SSI) algorithm......Operational Modal Analysis also known as Output Only Modal Analysis has in the recent years been used for extracting modal parameters of civil engineering structures and is now becoming popular for mechanical structures. The advantage of the method is that no artificial excitation need...

  3. Study on the Effect of the Impact Location and the Type of Hammer Tip on the Frequency Response Function (FRF) in Experimental Modal Analysis of Rectangular Plates

    Science.gov (United States)

    Mali, K. D.; Singru, P. M.

    2018-03-01

    In this work effect of the impact location and the type of hammer tip on the frequency response function (FRF) is studied. Experimental modal analysis of rectangular plates is carried out for this purpose by using impact hammer, accelerometer and fast Fourier transform (FFT) analyzer. It is observed that the impulse hammer hit location has, no effect on the eigenfrequency, yet a difference in amplitude of the eigenfrequencies is obtained. The effect of the hammer tip on the pulse and the force spectrum is studied for three types of tips metal, plastic and rubber. A solid rectangular plate was excited by using these tips one by one in three different tests. It is observed that for present experimental set up plastic tip excites the useful frequency range.

  4. Toward predicate approaches to modality

    CERN Document Server

    Stern, Johannes

    2016-01-01

    In this volume, the author investigates and argues for, a particular answer to the question: What is the right way to logically analyze modalities from natural language within formal languages? The answer is: by formalizing modal expressions in terms of predicates. But, as in the case of truth, the most intuitive modal principles lead to paradox once the modal notions are conceived as predicates. The book discusses the philosophical interpretation of these modal paradoxes and argues that any satisfactory approach to modality will have to face the paradoxes independently of the grammatical category of the modal notion. By systematizing modal principles with respect to their joint consistency and inconsistency, Stern provides an overview of the options and limitations of the predicate approach to modality that may serve as a useful starting point for future work on predicate approaches to modality. Stern also develops a general strategy for constructing philosophically attractive theories of modal notions conce...

  5. Endobronchial Ultrasound-guided Transbronchial Needle Aspiration versus Standard Bronchoscopic Modalities for Diagnosis of Sarcoidosis: A Meta-analysis

    Directory of Open Access Journals (Sweden)

    Li-Xing Hu

    2016-01-01

    Conclusions: The results of this meta-analysis suggest that EBUS-TBNA + TBLB + EBB could be used for the diagnosis of sarcoidosis, if available. At medical centers without EBUS-TBNA, TBNA + TBLB + EBB could be used instead.

  6. Detection of cervical lymph node metastasis in head and neck cancer patients with clinically N0 neck—a meta-analysis comparing different imaging modalities

    International Nuclear Information System (INIS)

    Liao, Li-Jen; Lo, Wu-Chia; Hsu, Wan-Lun; Wang, Chi-Te; Lai, Mei-Shu

    2012-01-01

    How to properly manage clinically negative neck of head and neck cancer patients is a controversial topic. Research is now directed toward finding a method sensitive enough to bring the risk of occult metastases below 20%. The aim of this review was to compare the diagnostic accuracy of different imaging modalities, including CT, MRI, PET and US, in clinically N0 head and neck cancer patients. For this systematic review and meta-analysis, PubMed and the Cochrane Database were searched for relevant original articles published up to May 2011. Inclusion criteria were as follows: articles were reported in English; CT, MRI, PET or US were performed to identify cervical metastases in clinically N0 head and neck squamous cell carcinoma; and data were sufficient for the calculation of true-positive or false-negative values. A bivariate random effect model was used to obtain pooled sensitivity and specificity. The positive and negative test probability of neck metastasis was generated based on Bayesian theory and collected data for different pre-test possibilities. Of the 168 identified relevant articles, 7 studies fulfilled all inclusion criteria for CT, 6 studies for MRI, 11 studies for PET and 8 studies for US. There was no difference in sensitivity and specificity among these imaging modalities, except CT was superior to US in specificity. The pooled estimates for sensitivity were 52% (95% confidence interval [CI], 39% ~ 65%), 65% (34 ~ 87%) 66% (47 ~ 80%), and 66% (45 ~ 77%), on a per-neck basis for CT, MRI, PET and US, respectively. The pooled estimates for specificity were 93% (87% ~ 97%), 81% (64 ~ 91%), 87% (77 ~ 93%), and 78% (71 ~ 83%) for CT, MRI, PET and US, respectively. With pre-examination nodal metastasis probabilities set at 10%, 20% and 30%, the post-exam probabilities of positive nodal metastasis rates were 47%, 66% and 77% for CT; 27%, 46% and 59% for MRI; 36%, 56% and 69% for PET; and 25%, 42% and 56% for US, respectively. Negative nodal metastasis

  7. Use of personal computers in performing a linear modal analysis of a large finite-element model

    International Nuclear Information System (INIS)

    Wagenblast, G.R.

    1991-01-01

    This paper presents the use of personal computers in performing a dynamic frequency analysis of a large (2,801 degrees of freedom) finite-element model. Large model linear time history dynamic evaluations of safety related structures were previously restricted to mainframe computers using direct integration analysis methods. This restriction was a result of the limited memory and speed of personal computers. With the advances in memory capacity and speed of the personal computers, large finite-element problems now can be solved in the office in a timely and cost effective manner. Presented in three sections, this paper describes the procedure used to perform the dynamic frequency analysis of the large (2,801 degrees of freedom) finite-element model on a personal computer. Section 2.0 describes the structure and the finite-element model that was developed to represent the structure for use in the dynamic evaluation. Section 3.0 addresses the hardware and software used to perform the evaluation and the optimization of the hardware and software operating configuration to minimize the time required to perform the analysis. Section 4.0 explains the analysis techniques used to reduce the problem to a size compatible with the hardware and software memory capacity and configuration

  8. Outcomes of non-invasive diagnostic modalities for the detection of coronary artery disease: network meta-analysis of diagnostic randomised controlled trials.

    Science.gov (United States)

    Siontis, George Cm; Mavridis, Dimitris; Greenwood, John P; Coles, Bernadette; Nikolakopoulou, Adriani; Jüni, Peter; Salanti, Georgia; Windecker, Stephan

    2018-02-21

    To evaluate differences in downstream testing, coronary revascularisation, and clinical outcomes following non-invasive diagnostic modalities used to detect coronary artery disease. Systematic review and network meta-analysis. Medline, Medline in process, Embase, Cochrane Library for clinical trials, PubMed, Web of Science, SCOPUS, WHO International Clinical Trials Registry Platform, and Clinicaltrials.gov. Diagnostic randomised controlled trials comparing non-invasive diagnostic modalities in patients presenting with symptoms suggestive of low risk acute coronary syndrome or stable coronary artery disease. A random effects network meta-analysis synthesised available evidence from trials evaluating the effect of non-invasive diagnostic modalities on downstream testing and patient oriented outcomes in patients with suspected coronary artery disease. Modalities included exercise electrocardiograms, stress echocardiography, single photon emission computed tomography-myocardial perfusion imaging, real time myocardial contrast echocardiography, coronary computed tomographic angiography, and cardiovascular magnetic resonance. Unpublished outcome data were obtained from 11 trials. 18 trials of patients with low risk acute coronary syndrome (n=11 329) and 12 trials of those with suspected stable coronary artery disease (n=22 062) were included. Among patients with low risk acute coronary syndrome, stress echocardiography, cardiovascular magnetic resonance, and exercise electrocardiograms resulted in fewer invasive referrals for coronary angiography than coronary computed tomographic angiography (odds ratio 0.28 (95% confidence interval 0.14 to 0.57), 0.32 (0.15 to 0.71), and 0.53 (0.28 to 1.00), respectively). There was no effect on the subsequent risk of myocardial infarction, but estimates were imprecise. Heterogeneity and inconsistency were low. In patients with suspected stable coronary artery disease, an initial diagnostic strategy of stress echocardiography or

  9. Outcomes of non-invasive diagnostic modalities for the detection of coronary artery disease: network meta-analysis of diagnostic randomised controlled trials

    Science.gov (United States)

    Siontis, George CM; Mavridis, Dimitris; Greenwood, John P; Coles, Bernadette; Nikolakopoulou, Adriani; Jüni, Peter; Salanti, Georgia

    2018-01-01

    Abstract Objective To evaluate differences in downstream testing, coronary revascularisation, and clinical outcomes following non-invasive diagnostic modalities used to detect coronary artery disease. Design Systematic review and network meta-analysis. Data sources Medline, Medline in process, Embase, Cochrane Library for clinical trials, PubMed, Web of Science, SCOPUS, WHO International Clinical Trials Registry Platform, and Clinicaltrials.gov. Eligibility criteria for selecting studies Diagnostic randomised controlled trials comparing non-invasive diagnostic modalities in patients presenting with symptoms suggestive of low risk acute coronary syndrome or stable coronary artery disease. Data synthesis A random effects network meta-analysis synthesised available evidence from trials evaluating the effect of non-invasive diagnostic modalities on downstream testing and patient oriented outcomes in patients with suspected coronary artery disease. Modalities included exercise electrocardiograms, stress echocardiography, single photon emission computed tomography-myocardial perfusion imaging, real time myocardial contrast echocardiography, coronary computed tomographic angiography, and cardiovascular magnetic resonance. Unpublished outcome data were obtained from 11 trials. Results 18 trials of patients with low risk acute coronary syndrome (n=11 329) and 12 trials of those with suspected stable coronary artery disease (n=22 062) were included. Among patients with low risk acute coronary syndrome, stress echocardiography, cardiovascular magnetic resonance, and exercise electrocardiograms resulted in fewer invasive referrals for coronary angiography than coronary computed tomographic angiography (odds ratio 0.28 (95% confidence interval 0.14 to 0.57), 0.32 (0.15 to 0.71), and 0.53 (0.28 to 1.00), respectively). There was no effect on the subsequent risk of myocardial infarction, but estimates were imprecise. Heterogeneity and inconsistency were low. In patients with

  10. The modal study

    International Nuclear Information System (INIS)

    Cook, J.R.

    1988-01-01

    The term ''Modal Study'' refers to a research program conducted for the Nuclear Regulatory Commission (NRC) on the level of protection provided by NRC-certified packages during the shipment of spent nuclear fuel form U.S. power reactors. The objective of the study was to examine the response of the packages to actual highway and railway accident conditions. The Modal Study results show that NRC-certified spent fuel casks would perform their safety functions under severe, actual accident conditions. The study also explains how NRC's cask design conditions, which are expressed in engineering terms, relate to actual accident conditions, with which the public is more familiar. The Modal Study, along with other transportation studies, physical testing of casks, and the spent fuel shipment safety record confirm the view that casks provide a high level of public safety during spent fuel transport

  11. Experimental Characterization of a Grid-Loss Event on a 2.5-MW Dynamometer Using Advanced Operational Modal Analysis: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Helsen, J.; Weijtjens, W.; Guo, Y.; Keller, J.; McNiff, B.; Devriendt, C.; Guillaume, P.

    2015-02-01

    This paper experimentally investigates a worst case grid loss event conducted on the National Renewable Energy Laboratory (NREL) Gearbox Reliability Collaborative (GRC) drivetrain mounted on the 2.5MW NREL dynamic nacelle test-rig. The GRC drivetrain has a directly grid-coupled, fixed speed asynchronous generator. The main goal is the assessment of the dynamic content driving this particular assess the dynamic content of the high-speed stage of the GRC gearbox. In addition to external accelerometers, high frequency sampled measurements of strain gauges were used to assess torque fluctuations and bending moments both at the nacelle main shaft and gearbox high-speed shaft (HSS) through the entire duration of the event. Modal analysis was conducted using a polyreference Least Squares Complex Frequency-domain (pLSCF) modal identification estimator. The event driving the torsional resonance was identified. Moreover, the pLSCF estimator identified main drivetrain resonances based on a combination of acceleration and strain measurements. Without external action during the grid-loss event, a mode shape characterized by counter phase rotation of the rotor and generator rotor determined by the drivetrain flexibility and rotor inertias was the main driver of the event. This behavior resulted in significant torque oscillations with large amplitude negative torque periods. Based on tooth strain measurements of the HSS pinion, this work showed that at each zero-crossing, the teeth lost contact and came into contact with the backside flank. In addition, dynamic nontorque loads between the gearbox and generator at the HSS played an important role, as indicated by strain gauge-measurements.

  12. Imaging modalities in the diagnosis of pancreatic adenocarcinoma: A systematic review and meta-analysis of sensitivity, specificity and diagnostic accuracy.

    Science.gov (United States)

    Toft, James; Hadden, William J; Laurence, Jerome M; Lam, Vincent; Yuen, Lawrence; Janssen, Anna; Pleass, Henry

    2017-07-01

    Pancreatic cancer, primarily pancreatic ductal adenocarcinoma (PDAC), accounts for 2.4% of cancer diagnoses and 5.8% of cancer death annually. Early diagnoses can improve 5-year survival in PDAC. The aim of this systematic review was to determine the sensitivity, specificity and diagnostic accuracy values for MRI, CT, PET&PET/CT, EUS and transabdominal ultrasound (TAUS) in the diagnosis of PDAC. A systematic review was undertaken to identify studies reporting sensitivity, specificity and/or diagnostic accuracy for the diagnosis of PDAC with MRI, CT, PET, EUS or TAUS. Proportional meta-analysis was performed for each modality. A total of 5399 patients, 3567 with PDAC, from 52 studies were included. The sensitivity, specificity and diagnostic accuracy were 93% (95% CI=88-96), 89% (95% CI=82-94) and 90% (95% CI=86-94) for MRI; 90% (95% CI=87-93), 87% (95% CI=79-93) and 89% (95% CI=85-93) for CT; 89% (95% CI=85-93), 70% (95% CI=54-84) and 84% (95% CI=79-89) for PET; 91% (95% CI=87-94), 86% (95% CI=81-91) and 89% (95% CI=87-92) for EUS; and 88% (95% CI=86-90), 94% (95% CI=87-98) and 91% (95% C=87-93) for TAUS. This review concludes all modalities, except for PET, are equivalent within 95% confidence intervals for the diagnosis of PDAC. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Parametric modal transition systems

    DEFF Research Database (Denmark)

    Beneš, Nikola; Křetínský, Jan; Larsen, Kim Guldstrand

    2011-01-01

    Modal transition systems (MTS) is a well-studied specification formalism of reactive systems supporting a step-wise refinement methodology. Despite its many advantages, the formalism as well as its currently known extensions are incapable of expressing some practically needed aspects in the refin......Modal transition systems (MTS) is a well-studied specification formalism of reactive systems supporting a step-wise refinement methodology. Despite its many advantages, the formalism as well as its currently known extensions are incapable of expressing some practically needed aspects...

  14. [Modal failure analysis and effects in the detection of errors in the transport of samples to the clinical laboratory].

    Science.gov (United States)

    Parés-Pollán, L; Gonzalez-Quintana, A; Docampo-Cordeiro, J; Vargas-Gallego, C; García-Álvarez, G; Ramos-Rodríguez, V; Diaz Rubio-García, M P

    2014-01-01

    Owing to the decrease in values of biochemical glucose parameter in some samples from external extraction centres, and the risk this implies to patient safety; it was decided to apply an adaptation of the «Health Services Failure Mode and Effects Analysis» (HFMEA) to manage risk during the pre-analytical phase of sample transportation from external centres to clinical laboratories. A retrospective study of glucose parameter was conducted during two consecutive months. The analysis was performed in its different phases: to define the HFMEA topic, assemble the team, graphically describe the process, conduct a hazard analysis, design the intervention and indicators, and identify a person to be responsible for ensuring completion of each action. The results of glucose parameter in one of the transport routes, were significantly lower (P=.006). The errors and potential causes of this problem were analysed, and criteria of criticality and detectability were applied (score≥8) in the decision tree. It was decided to: develop a document management system; reorganise extractions and transport routes in some centres; quality control of the sample container ice-packs, and the time and temperature during transportation. This work proposes quality indicators for controlling time and temperature of transported samples in the pre-analytical phase. Periodic review of certain laboratory parameters can help to detect problems in transporting samples. The HFMEA technique is useful for the clinical laboratory. Copyright © 2013 SECA. Published by Elsevier Espana. All rights reserved.

  15. Conceptual structure within and between modalities

    Directory of Open Access Journals (Sweden)

    Katia eDilkina

    2013-01-01

    Full Text Available Current views of semantic memory share the assumption that conceptual representations are based on multi-modal experience, which activates distinct modality-specific brain regions. This proposition is widely accepted, yet little is known about how each modality contributes to conceptual knowledge and how the structure of this contribution varies across these multiple information sources. We used verbal feature lists, features from drawings and verbal co-occurrence statistics from latent semantic analysis to examine the informational structure in four domains of knowledge: perceptual, functional, encyclopedic and verbal. The goals of the analysis were three-fold: (1 to assess the structure within individual modalities; (2 to compare structures between modalities; and (3 to assess the degree to which concepts organize categorically or randomly.Our results indicated significant and unique structure in all four modalities: perceptually, concepts organize based on prominent features such as shape, size, color and parts; functionally, they group based on use and interaction; encyclopedically, they arrange based on commonality in location or behavior; and verbally, they group associatively or relationally. Visual/perceptual knowledge gives rise to the strongest hierarchical organization and is closest to classic taxonomic structure. Information is organized somewhat similarly in the perceptual and encyclopedic domains, which differs significantly from the structure in the functional and verbal domains. Notably, the verbal modality has the most unique organization, which is not at all categorical but also not random. The idiosyncrasy and complexity of conceptual structure across modalities begs the question of how all of these modality-specific experiences are fused together into coherent, multi-faceted yet unified concepts. Accordingly, both methodological and theoretical implications of the present findings are discussed.

  16. Diagnostic Accuracy of Imaging Modalities and Injection Techniques for the Diagnosis of Femoroacetabular Impingement/Labral Tear: A Systematic Review With Meta-analysis.

    Science.gov (United States)

    Reiman, Michael P; Thorborg, Kristian; Goode, Adam P; Cook, Chad E; Weir, Adam; Hölmich, Per

    2017-09-01

    Diagnosing femoroacetabular impingement/acetabular labral tear (FAI/ALT) and subsequently making a decision regarding surgery are based primarily on diagnostic imaging and intra-articular hip joint injection techniques of unknown accuracy. Summarize and evaluate the diagnostic accuracy and clinical utility of various imaging modalities and injection techniques relevant to hip FAI/ALT. Systematic review with meta-analysis. A computer-assisted literature search was conducted of MEDLINE, CINAHL, and EMBASE databases using keywords related to diagnostic accuracy of hip joint pathologic changes. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were used for the search and reporting phases of the study. Quality assessment of bias and applicability was conducted using the Quality of Diagnostic Accuracy Studies (QUADAS) tool. Random effects models were used to summarize sensitivities (SN), specificities (SP), likelihood ratios (+LR and -LR), diagnostic odds ratios (DOR), and respective confidence intervals (CI). The search strategy and assessment for risk of bias revealed 25 articles scoring above 10/14 on the items of the QUADAS. Four studies investigated FAI, and the data were not pooled. Twenty articles on ALT qualified for meta-analysis. Pretest probability of ALT in the studies in this review was 81% (72%-88%), while the pretest probability of FAI diagnosis was 74% (95% CI, 51%-91%). The meta-analysis showed that computed tomography arthrography (CTA) demonstrated the strongest overall diagnostic accuracy: pooled SN 0.91 (95% CI, 0.83-0.96); SP 0.89 (95% CI, 0.74-0.97); +LR 6.28 (95% CI, 2.78-14.21); -LR 0.11 (95% CI, 0.06-0.21); and DOR 64.38 (95% CI, 19.17-216.21). High pretest probability of disease was demonstrated. Positive imaging findings increased the probability that a labral tear existed by a minimal to small degree with the use of magnetic resonance imaging/magnetic resonance angiogram (MRI/MRA) and ultrasound (US

  17. Tense, aspect, and modality

    NARCIS (Netherlands)

    Pfau, R.; Steinbach, M.; Woll, B.; Pfau, R.; Steinbach, M.; Woll, B.

    2012-01-01

    Cross-linguistically, the grammatical categories tense, aspect, and modality - when they are overtly expressed - are generally realized by free morphemes (such as adverbials and auxiliaries) or by bound inflectional markers. The discussion in this chapter will make clear that this generalization

  18. A Modality Called 'Negation'

    NARCIS (Netherlands)

    Berto, F.

    2015-01-01

    I propose a comprehensive account of negation as a modal operator, vindicating a moderate logical pluralism. Negation is taken as a quantifier on worlds, restricted by an accessibility relation encoding the basic concept of compatibility. This latter captures the core meaning of the operator. While

  19. Supply of Liquefied Natural Gas according to the European Federation of Energy Traders. An analysis of the applied supply modality

    International Nuclear Information System (INIS)

    Van de Linde, D.M.

    2010-01-01

    This article addresses the relation between the title subject and the status of the so-called International Commercial Terms and their place in laws and regulations. Subsequently, an analysis is conducted of the title, risk and ownership transfer within LNG MA (Master Delivery Ex Ship (DES) LNG Sale and Purchase Agreement). Moreover, attention is paid to various obligations in view of the International Treaty of 1996 regarding liability and compensation for damage caused by sea shipping of dangerous and hazardous substances (HNS treaty). Finally, an answer is provided to the question whether the Incoterm DES is the best Incoterm, or if a better alternative is provided by the International Chamber of Commerce. [nl

  20. An Analysis of Public Transit Connectivity Index in Tehran. The Case Study: Tehran Multi-Modal Transit Network

    Directory of Open Access Journals (Sweden)

    Amir Reza Mamdoohi

    2016-10-01

    Full Text Available Public transit is a major priority in modern management of large cities and metropolitan areas in particular. Public transit systems in such cities consist of a large number of nodes and lines which are represented by a complex network. A station for public transit is a bridge between the people and public transit network, based on which, the concept of input and output power for each station can be defined. The objective of this study is the application of the transit connectivity indices to the multimodal transit network in the city of Tehran. The public transit network data employed in this study is taken from Tehran Traffic Control Company, and Tehran Urban and Suburban Railway Operation Company. The methodology for measuring transit connectivity consists of three measures: Node connectivity, Line connectivity and Regional connectivity, where activity density is applied to these measures. The results of node connectivity analysis shows that most of the node connectivity in concentrated in the city center with many nodes in the center along routes going north and south. The line connectivity analysis shows that there is a concentration of highly connected lines that are near Tehran municipality region 12 and 16. Finally, we find that areas with more metro and bus facilities with respect to the other areas, have a better regional connectivity. One of these areas includes Sadeghiyeh Metro Station which is the junction of Tehran Metro Line 2 and Tehran Metro Line 5 which have a high connectivity power. Results of this study can be used to suggest some ideas on how future investments in rail and bus should be prioritized. Particularly in Transit Oriented Development (TOD and sustainble development projects, urban planners can design transit stations with high performance to access the crucial services in poor areas.

  1. Prospective analysis of the port-wine stain patient population in the Netherlands in light of novel treatment modalities.

    Science.gov (United States)

    van Raath, M Ingmar; Bambach, Caroline A; Dijksman, Lea M; Wolkerstorfer, Albert; Heger, Michal

    2018-04-01

    Pulsed dye laser is the gold standard for port-wine stain (PWS) treatment. However, pulsed dye lasers achieve suboptimal clinical results in a majority of patients. Patient demand for novel therapies and willingness to participate in clinical studies is currently unknown, yet, imperative for steering R&D activity. The objective of this study was to evaluate these two factors in relation to PWS patient demographics. A questionnaire was used to assess patient and PWS characteristics, treatment history, efficacy, and satisfaction, stress level, willingness to travel and pay for an effective treatment, participation in clinical studies, and amenability to intravenous drug administration. Descriptive statistics and correlation analysis were performed. Of the respondents (N = 108), 65% would participate in clinical studies and 49% would accept intravenous drugs. For an effective treatment, 58% was prepared to pay over €2,000 and 48% would travel more than 6 h. Travel time was inversely correlated with age, clearance rate, and satisfaction. Facial PWS patients had undergone more treatments, were less satisfied, and less willing to participate in studies or accept intravenous drugs. Stress levels were higher in females. There is considerable demand for new PWS therapies, and a substantial proportion of patients are willing to participate in clinical studies.

  2. Optimum design of large span concrete filled steel tubular arch bridge based on static, stability and modal analysis

    Institute of Scientific and Technical Information of China (English)

    赵长军; 胡隽; 徐兴

    2002-01-01

    A three-dimensional finite element model was established for a large span concrete filled steel tubular (CFST) arch bridge which is currently under construction. The arch rib, the spandrel columns, the prestressed concrete box-beam, the cast-in-situ concrete plate of bridge deck, the steel box-beam and the crossbeams connecting the two pieces of arch ribs, were modeled by three-dimensional Timoshenko beam elements (3DTBE). The suspenders were modeled by three-dimensional cable elements (3DCE). Both geometric nonlinearity and prestress effect could be included in each kind of element. At the same time a second finite element model with the same geometric and material properties excepted for the sectional dimension of arch rib was set up. Static dynamic analyses were performed to determine the corresponding characteristics of the structure. The results showed that the arch rib's axial rigidity could be determined by static analysis. The stability and vibration of this system could be separated into in-plane modes, out-of-plane modes and coupled modes. The in-plane stability and dynamic characteristics are determined by the arch rib's vertical stiffness and that of out-of-plane is determined by the crossbeams' stiffness and arch rib's lateral stiffness mainly. The in-plane stiffness is much greater than that of out-of-plane for this kind of bridge . The effect of geometric nonlinearity and prestress effect on bridge behavior is insignificant.

  3. A comparative analysis of modal motions for the gyroscopic and non-gyroscopic two degree-of-freedom conservative systems

    Science.gov (United States)

    Yang, Xiao-Dong; An, Hua-Zhen; Qian, Ying-Jing; Zhang, Wei; Melnik, Roderick V. N.

    2016-12-01

    The synchronous in-unison motions in vibrational mechanics and the non-synchronous out-of-unison motions are the most frequently found periodic motions in every fields of science and everywhere in the universe. In contrast to the in-unison normal modes, the out-of-unison complex modes feature a π/2 phase difference. By the complex mode analysis we classify the out-of-unison planar motion into two types, gyroscopic motions and elliptic motions. It is found that the gyroscopic and elliptic motions have different characteristics for a two degree-of-freedom (2DOF) system. The gyroscopic motion involves two distinct frequencies with, respectively, two corresponding complex modes. However, the elliptic motion the nonlinear non-gyroscopic 2DOF system with repeated frequencies involves only single frequency with corresponding two complex modes. The study of the differences and similarities of the gyroscopic and elliptic modes sheds new light on the in-depth mechanism of the planar motions in the universe and the man-made engineering systems.

  4. Validation of the Open Source Code_Aster Software Used in the Modal Analysis of the Fluid-filled Cylindrical Shell

    Directory of Open Access Journals (Sweden)

    B D. Kashfutdinov

    2017-01-01

    Full Text Available The paper deals with a modal analysis of the elastic cylindrical shell with a clamped bottom partially filled with fluid in open source Code_Aster software using the finite element method. Natural frequencies and modes obtained in Code_Aster are compared to experimental and theoretical data. The aim of this paper is to prove that Code_Aster has all necessary tools for solving fluid structure interaction problems. Also, Code_Aster can be used in the industrial projects as an alternative to commercial software. The available free pre- and post-processors with a graphical user interface that is compatible with Code_Aster allow creating complex models and processing the results.The paper presents new validation results of open source Code_Aster software used to calculate small natural modes of the cylindrical shell partially filled with non-viscous compressible barotropic fluid under gravity field.The displacement of the middle surface of thin shell and the displacement of the fluid relative to the equilibrium position are described by coupled hydro-elasticity problem. The fluid flow is considered to be potential. The finite element method (FEM is used. The features of computational model are described. The resolution equation has symmetrical block matrices. To compare the results, is discussed the well-known modal analysis problem of cylindrical shell with flat non-deformable bottom, filled with a compressible fluid. The numerical parameters of the scheme were chosen in accordance with well-known experimental and analytical data. Three cases were taken into account: an empty, a partially filled and a full-filled cylindrical shell.The frequencies of Code_Aster are in good agreement with those, obtained in experiment, analytical solution, as well as with results obtained by FEM in other software. The difference between experiment and analytical solution in software is approximately the same. The obtained results extend a set of validation tests for

  5. EXPLOSIVE NUCLEOSYNTHESIS IN THE NEUTRINO-DRIVEN ASPHERICAL SUPERNOVA EXPLOSION OF A NON-ROTATING 15 Msun STAR WITH SOLAR METALLICITY

    International Nuclear Information System (INIS)

    Fujimoto, Shin-ichiro; Kotake, Kei; Hashimoto, Masa-aki; Ono, Masaomi; Ohnishi, Naofumi

    2011-01-01

    We investigate explosive nucleosynthesis in a non-rotating 15 M sun star with solar metallicity that explodes by a neutrino-heating supernova (SN) mechanism aided by both standing accretion shock instability (SASI) and convection. To trigger explosions in our two-dimensional hydrodynamic simulations, we approximate the neutrino transport with a simple light-bulb scheme and systematically change the neutrino fluxes emitted from the protoneutron star. By a post-processing calculation, we evaluate abundances and masses of the SN ejecta for nuclei with a mass number ≤70, employing a large nuclear reaction network. Aspherical abundance distributions, which are observed in nearby core-collapse SN remnants, are obtained for the non-rotating spherically symmetric progenitor, due to the growth of a low-mode SASI. The abundance pattern of the SN ejecta is similar to that of the solar system for models whose masses range between (0.4-0.5) M sun of the ejecta from the inner region (≤10, 000 km) of the precollapse core. For the models, the explosion energies and the 56 Ni masses are ≅ 10 51 erg and (0.05-0.06) M sun , respectively; their estimated baryonic masses of the neutron star are comparable to the ones observed in neutron-star binaries. These findings may have little uncertainty because most of the ejecta is composed of matter that is heated via the shock wave and has relatively definite abundances. The abundance ratios for Ne, Mg, Si, and Fe observed in the Cygnus loop are reproduced well with the SN ejecta from an inner region of the 15 M sun progenitor.

  6. Modal Logics with Counting

    Science.gov (United States)

    Areces, Carlos; Hoffmann, Guillaume; Denis, Alexandre

    We present a modal language that includes explicit operators to count the number of elements that a model might include in the extension of a formula, and we discuss how this logic has been previously investigated under different guises. We show that the language is related to graded modalities and to hybrid logics. We illustrate a possible application of the language to the treatment of plural objects and queries in natural language. We investigate the expressive power of this logic via bisimulations, discuss the complexity of its satisfiability problem, define a new reasoning task that retrieves the cardinality bound of the extension of a given input formula, and provide an algorithm to solve it.

  7. Constructions, pragmatics and modality

    Directory of Open Access Journals (Sweden)

    Antonio Fortin

    2013-05-01

    Full Text Available This paper rejects the commonplace view that the semantics of certain modal deverbal adjectives (MDAs, which have traditionally been assumed to be non-compositional, require complex lexical or syntactic encoding (cf. e.g. Riehemann 1994 and 1998, Booij 2007 and 2010a. Instead, it shows that productive MDA formation is semantically compositional, and that the prima facie idiosyncratic meanings are, in fact, conversational implicatures.

  8. 从多模态角度浅析手机广告%A Brief Analysis of Mobile Advertisement from the Multi-modal Perspective

    Institute of Scientific and Technical Information of China (English)

    刘静

    2014-01-01

    20世纪90年代西方兴起的多模态话语分析,逐渐成为语言学研究的新热点之一。经过十多年的发展,多模态分析已从语言学逐渐延伸到其他领域,研究对象也从语言文字扩展到音乐、图片、视频等多种社会符号系统。于是,随着人类社会步入3G时代,手机的普及使得手机广告具有极大的发展市场,将多模态分析运用到手机广告中将是今后的必然趋势。该文试图从多模态分析角度对手机广告进行浅析。%Multimodal discourse analysis rising in the western in 1990s has gradually become a new hot spot of the linguistic re-search. After more than ten years of development, multimodal analysis is not only applied in linguistics, but also extended to other areas. The research object is also extended from language to music, pictures, video and other social symbols. Thus, as human soci-ety has entered the 3G era, the popularity of mobile phones makes the mobile advertising market has great development, and the multimodal analysis will be greatly applied to mobile advertising. This paper attempts to analyze mobile advertisement from a multi-modal perspective.

  9. Preferential reasoning for modal logics

    CSIR Research Space (South Africa)

    Britz, K

    2011-11-01

    Full Text Available Modal logic is the foundation for a versatile and well-established class of knowledge representation formalisms in artificial intelligence. Enriching modal logics with non-monotonic reasoning capabilities such as preferential reasoning as developed...

  10. Efficacy of Noninvasive Stellate Ganglion Blockade Performed Using Physical Agent Modalities in Patients with Sympathetic Hyperactivity-Associated Disorders: A Systematic Review and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Chun-De Liao

    Full Text Available Stellate ganglion blockade (SGB is mainly used to relieve symptoms of neuropathic pain in conditions such as complex regional pain syndrome and has several potential complications. Noninvasive SGB performed using physical agent modalities (PAMs, such as light irradiation and electrical stimulation, can be clinically used as an alternative to conventional invasive SGB. However, its application protocols vary and its clinical efficacy remains controversial. This study investigated the use of noninvasive SGB for managing neuropathic pain or other disorders associated with sympathetic hyperactivity.We performed a comprehensive search of the following online databases: Medline, PubMed, Excerpta Medica Database, Cochrane Library Database, Ovid MEDLINE, Europe PubMed Central, EBSCOhost Research Databases, CINAHL, ProQuest Research Library, Physiotherapy Evidence Database, WorldWideScience, BIOSIS, and Google Scholar. We identified and included quasi-randomized or randomized controlled trials reporting the efficacy of SGB performed using therapeutic ultrasound, transcutaneous electrical nerve stimulation, light irradiation using low-level laser therapy, or xenon light or linearly polarized near-infrared light irradiation near or over the stellate ganglion region in treating complex regional pain syndrome or disorders requiring sympatholytic management. The included articles were subjected to a meta-analysis and risk of bias assessment.Nine randomized and four quasi-randomized controlled trials were included. Eleven trials had good methodological quality with a Physiotherapy Evidence Database (PEDro score of ≥6, whereas the remaining two trials had a PEDro score of <6. The meta-analysis results revealed that the efficacy of noninvasive SGB on 100-mm visual analog pain score is higher than that of a placebo or active control (weighted mean difference, -21.59 mm; 95% CI, -34.25, -8.94; p = 0.0008.Noninvasive SGB performed using PAMs effectively relieves

  11. Efficacy of Noninvasive Stellate Ganglion Blockade Performed Using Physical Agent Modalities in Patients with Sympathetic Hyperactivity-Associated Disorders: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Liao, Chun-De; Tsauo, Jau-Yih; Liou, Tsan-Hon; Chen, Hung-Chou; Rau, Chi-Lun

    2016-01-01

    Stellate ganglion blockade (SGB) is mainly used to relieve symptoms of neuropathic pain in conditions such as complex regional pain syndrome and has several potential complications. Noninvasive SGB performed using physical agent modalities (PAMs), such as light irradiation and electrical stimulation, can be clinically used as an alternative to conventional invasive SGB. However, its application protocols vary and its clinical efficacy remains controversial. This study investigated the use of noninvasive SGB for managing neuropathic pain or other disorders associated with sympathetic hyperactivity. We performed a comprehensive search of the following online databases: Medline, PubMed, Excerpta Medica Database, Cochrane Library Database, Ovid MEDLINE, Europe PubMed Central, EBSCOhost Research Databases, CINAHL, ProQuest Research Library, Physiotherapy Evidence Database, WorldWideScience, BIOSIS, and Google Scholar. We identified and included quasi-randomized or randomized controlled trials reporting the efficacy of SGB performed using therapeutic ultrasound, transcutaneous electrical nerve stimulation, light irradiation using low-level laser therapy, or xenon light or linearly polarized near-infrared light irradiation near or over the stellate ganglion region in treating complex regional pain syndrome or disorders requiring sympatholytic management. The included articles were subjected to a meta-analysis and risk of bias assessment. Nine randomized and four quasi-randomized controlled trials were included. Eleven trials had good methodological quality with a Physiotherapy Evidence Database (PEDro) score of ≥6, whereas the remaining two trials had a PEDro score of <6. The meta-analysis results revealed that the efficacy of noninvasive SGB on 100-mm visual analog pain score is higher than that of a placebo or active control (weighted mean difference, -21.59 mm; 95% CI, -34.25, -8.94; p = 0.0008). Noninvasive SGB performed using PAMs effectively relieves pain of

  12. Dual modality densitometry

    International Nuclear Information System (INIS)

    Tjugum, Stein-Arild

    2003-01-01

    Different measurement principles and design issues for gamma-ray densitometry for pipe flow are investigated. The dual modality densitometry (DMD) principle for salinity measurement and flow regime identification by multibeam densitometry are tested and verified. The measurement principles are implemented in a compact instrument design with low energy source and compact detectors. The DMD principle is experimentally verified for 3 inch and 2 inch pipes. These measurements are done on homogenous brine/gas mixtures. Both salinity independent GVF measurements and salinity measurements are obtained. The standard deviation of the salinity measurements are about 2 percent. This measurement inaccuracy is mainly caused by inhomogeneity in the liquid/gas distribution, and measurements are thus sensitive to changes in the flow regime. Models for the generation of scattered radiation are developed, and these have been used in the data-analysis and for producing special sensitivity maps for the generation of scattered radiation. The models are a useful tool for further development of the DMD principle. The work on multibeam gamma-ray densitometry has shown that flow regimes can be identified with as few as two detectors. This is verified in the flow-loop tests. Unambiguous flow regime identification will often require that the multibeam measurements are combined with other flow measurements. With a higher number of detectors more detailed information is found, and from the 9-beam measurements with the University of Bergen (UoB) gamma-ray tomography different flow regimes could clearly be identified from time series plots of the data. A laboratory prototype compact gamma-ray densitometer, the MiniGamma, has been built up and tested. Both the DMD measurement principle and the multibeam arrangement for flow regime identification are implemented in the instrument, and are successfully tested. The detector-types tested are CdZnTe semiconductor detectors, a miniature scintillation

  13. Aeroelastic modal dynamics of wind turbines including anisotropic effects

    DEFF Research Database (Denmark)

    Skjoldan, Peter Fisker

    frequency is thus identified as the dominant frequency in the response of a pure excitation of the mode observed in the inertial frame. A modal analysis tool based directly on the complex aeroelastic wind turbine code BHawC is presented. It uses the Coleman approach in isotropic conditions......Several methods for aeroelastic modal analysis of a rotating wind turbine are developed and used to analyse the modal dynamics of two simplified models and a complex model in isotropic and anisotropic conditions. The Coleman transformation is used to enable extraction of the modal frequencies...... of Floquet analysis or Hill's method which do not provide a unique reference frame for observing the modal frequency, to which any multiple of the rotor speed can be added. This indeterminacy is resolved by requiring that the periodic mode shape be as constant as possible in the inertial frame. The modal...

  14. PENGARUH GOOD CORPORATE GOVERNANCE, KINERJA KEUANGAN, MODAL INTELEKTUAL TERHADAP PENGUNGKAPAN MODAL INTELEKTUAL

    Directory of Open Access Journals (Sweden)

    Gilang Anies Saendy

    2015-10-01

    Full Text Available Dampak perkembangan globalisasi membutuhkan informasi lebih lanjut, terutama informasi tentang modal intelektual perusahaan. Tapi, dalam kondisi nyata informasi modal intelektual masih rendah, yakni sekitar 27-35%. Objek penelitian ini adalah perbankan yang terdapat dalam direktori Pasar Modal Indonesia (ICMD 2010-2013. Jumlah populasi adalah 36 perbankan dan 17 sampel dengan menggunakan purposive sampling. Metode yang digunakan adalah analisis jalur. Hasil penelitian ini menunjukkan bahwa tidak pengaruh antara pelaksanaan GCG untuk pengungkapan modal intelektual dan kinerja keuangan. Selain itu, ada pengaruh positif antara kinerja modal intelektual terhadap kinerja keuangan dan kinerja keuangan untuk pengungkapan modal intelektual. Selanjutnya, hasil penelitian menunjukkan bahwa tidak efek mediasi melalui kinerja keuangan perusahaan antara implementasi GCG dalam pengungkapan modal intelektual. Hasilnya juga mengatakan ada efek mediasi antara pelaksanaan GCG untuk pengungkapan modal intelektual pikir kinerja modal intelektual. The development due to the increase of globalization gives impact to the need of having more information. One of them is the need to have information on company’s intellectual capital. But, in real condition, intellectual capital information is still low. It is about 27-35%. The objects of this research are banks organized in Indonesian Capital Market Directory (ICMD from 2010-2013. Total populations were 36 banks, and finally 17 samples were selected by using purposive sampling. The method used is path analysis. The results of this research show that there is no influence between GCG’s implementation on intellectual capital disclosure and financial performance. However, there are  positive influences of intellectual capital performance on the financial performance, and financial performance on the disclosure of intellectual capital. Besides, this research said that there is no effect of mediation through the company

  15. Modalization in the Political Column of Tempo Magazine

    OpenAIRE

    Rahmah, Maria Betti Sinaga and

    2017-01-01

    The study focuses on analyzing the use of modalization in the Political Column of Tempo Magazine. The objectives were to find out the type of modalization and to describe the use of modalization in the Political Column of Tempo magazine. The data were taken from Political Column of Tempo magazine published in June and July 2017. The source of data was Political Column in Tempo magazine. The data analysis applied descriptive qualitative research. There were 135 clauses which contained Modaliza...

  16. Multi-modal RGB–Depth–Thermal Human Body Segmentation

    DEFF Research Database (Denmark)

    Palmero, Cristina; Clapés, Albert; Bahnsen, Chris

    2016-01-01

    This work addresses the problem of human body segmentation from multi-modal visual cues as a first stage of automatic human behavior analysis. We propose a novel RGB-Depth-Thermal dataset along with a multi-modal seg- mentation baseline. The several modalities are registered us- ing a calibration...... to other state-of-the-art meth- ods, obtaining an overlap above 75% on the novel dataset when compared to the manually annotated ground-truth of human segmentations....

  17. Linguistic analysis of face-to-face interviews with patients with an explicit request for euthanasia, their closest relatives, and their attending physicians: the use of modal verbs in Dutch.

    Science.gov (United States)

    Dieltjens, Sylvain M; Heynderickx, Priscilla C; Dees, Marianne K; Vissers, Kris C

    2014-04-01

    The literature, field research, and daily practice stress the need for adequate communication in palliative care. Although language is of the utmost importance in communication, linguistic analysis of end-of-life discussions is scarce. Our aim is 2-fold: We want to determine what the use of 4 significant Dutch modal verbs expressing volition, obligation, possibility, and permission reveals about the concept of unbearable suffering and about physicians' communicative style. We quantitatively (TextStat) and qualitatively (bottom-up approach) analyzed the use of the modal verbs in 15 interviews, with patients requesting euthanasia or physician-assisted suicide, their physicians, and their closest relatives. An essential element of unbearable suffering is the patient's incapacity to perform certain tasks. Further, the physician's preference for particular modal verbs reveals whether his attitude toward patients is more or less patronizing and more or less appreciative. Linguistic analysis can help medical professionals to better understand their communicative skills, styles, and approach to patients in end-of-life situations. We have shown how linguistic analysis can contribute to a better understanding of physician-patient interaction. Moreover, we have illustrated the usefulness of interdisciplinary research in the medical domain. © 2013 World Institute of Pain.

  18. Modal Vibration Control in Periodic Time-Varying Structures with Focus on Rotor Blade Systems

    DEFF Research Database (Denmark)

    Christensen, Rene Hardam; Santos, Ilmar

    2004-01-01

    of active modal controllers. The main aim is to reduce vibrations in periodic time-varying structures. Special emphasis is given to vibration control of coupled bladed rotor systems. A state feedback modal control law is developed based on modal analysis in periodic time-varying structures. The first step...... in the procedure is a transformation of the model into a time-invariant modal form by applying the modal matrices, which are also periodic time-variant. Due to coupled rotor and blade motions complex vibration modes occur in the modal transformed state space model. This implies that the modal transformed model...

  19. Metaphysical Modality, Modality of Predicate and the Theory of

    Directory of Open Access Journals (Sweden)

    l nabavi

    2010-05-01

    This paper discusses the historical overview of the metaphysical modality firstly and then shows that the theory of "Decisive Necessity” is true and justified in a model of modal logic with equivalent accessibility relation and homogeneous possible world view (fixed domain.

  20. Effects of auditory and visual modalities in recall of words.

    Science.gov (United States)

    Gadzella, B M; Whitehead, D A

    1975-02-01

    Ten experimental conditions were used to study the effects of auditory and visual (printed words, uncolored and colored pictures) modalities and their various combinations with college students. A recall paradigm was employed in which subjects responded in a written test. Analysis of data showed the auditory modality was superior to visual (pictures) ones but was not significantly different from visual (printed words) modality. In visual modalities, printed words were superior to colored pictures. Generally, conditions with multiple modes of representation of stimuli were significantly higher than for conditions with single modes. Multiple modalities, consisting of two or three modes, did not differ significantly from each other. It was concluded that any two modalities of the stimuli presented simultaneously were just as effective as three in recall of stimulus words.

  1. Right ventricular functional analysis utilizing first pass radionuclide angiography for pre-operative ventricular assist device planning: a multi-modality comparison.

    Science.gov (United States)

    Avery, Ryan; Day, Kevin; Jokerst, Clinton; Kazui, Toshinobu; Krupinski, Elizabeth; Khalpey, Zain

    2017-10-10

    Advanced heart failure treated with a left ventricular assist device is associated with a higher risk of right heart failure. Many advanced heart failures patients are treated with an ICD, a relative contraindication to MRI, prior to assist device placement. Given this limitation, left and right ventricular function for patients with an ICD is calculated using radionuclide angiography utilizing planar multigated acquisition (MUGA) and first pass radionuclide angiography (FPRNA), respectively. Given the availability of MRI protocols that can accommodate patients with ICDs, we have correlated the findings of ventricular functional analysis using radionuclide angiography to cardiac MRI, the reference standard for ventricle function calculation, to directly correlate calculated ejection fractions between these modalities, and to also assess agreement between available echocardiographic and hemodynamic parameters of right ventricular function. A retrospective review from January 2012 through May 2014 was performed to identify advanced heart failure patients who underwent both cardiac MRI and radionuclide angiography for ventricular functional analysis. Nine heart failure patients (8 men, 1 woman; mean age of 57.0 years) were identified. The average time between the cardiac MRI and radionuclide angiography exams was 38.9 days (range: 1 - 119 days). All patients undergoing cardiac MRI were scanned using an institutionally approved protocol for ICD with no device-related complications identified. A retrospective chart review of each patient for cardiomyopathy diagnosis, clinical follow-up, and echocardiogram and right heart catheterization performed during evaluation was also performed. The 9 patients demonstrated a mean left ventricular ejection fraction (LVEF) using cardiac MRI of 20.7% (12 - 40%). Mean LVEF using MUGA was 22.6% (12 - 49%). The mean right ventricular ejection fraction (RVEF) utilizing cardiac MRI was 28.3% (16 - 43%), and the mean RVEF calculated by

  2. Long-term outcome of combined modality therapy in retroperitoneal and deep-trunk soft-tissue sarcoma: analysis of prognostic factors

    International Nuclear Information System (INIS)

    Youssef, Emad; Fontanesi, James; Mott, Michael; Kraut, Michael; Lucas, David; Mekhael, Hany; Ben-Josef, Edgar

    2002-01-01

    Purpose: To evaluate the long-term outcome of surgery and postoperative radiotherapy (RT) in retroperitoneal and deep-trunk soft-tissue sarcoma, and to identify the prognostic factors for local control, disease-free survival, and overall survival. Methods and Materials: Between January 1980 and December 1998, 60 patients with nonmetastatic retroperitoneal and deep-trunk soft-tissue sarcoma were treated at Wayne State University using combined surgery and RT. The location was retroperitoneal in 38 patients (63%) and deep trunk in 22 (27%). Forty-six patients (76%) were treated for primary disease and 14 (24%) for recurrent disease. The resection margins were negative in 24 patients (40%), close in 3 (5%), and positive in 33 (55%; 18 microscopic and 15 macroscopic). The median tumor size was 8.6 cm (range 2-55). External beam RT (EBRT; median dose 5220 cGy) was given to 44 patients (73%) and combined EBRT (median dose 4200 cGy) and brachytherapy (median dose 1600 cGy) to 16 patients (27%). Univariate and multivariate Cox regression analyses were conducted to identify the possible associations between patient age, race, gender, tumor site, histologic features, grade, size, stage, surgical margin, RT dose, modality (EBRT vs. EBRT plus brachytherapy), and presentation (primary vs. recurrent) and disease control. Results: The actuarial 5- and 10-year disease-free survival rate was 53% and 44%, respectively. Disease-free survival was significantly associated with female gender on univariate analysis (67% for female patients and 37% for male patients at 5 years, p=0.05). On multivariate analysis, both gender and surgical margin had borderline significance (p=0.06). The actuarial local control rate was 71% and 54% at 5 and 10 years, respectively. The median time to local relapse was 10.2 months, with 75% of all failures occurring within 29 months. The surgical margin status was significantly associated with local control (78% for patients with negative or close margins vs

  3. Efficacy of Noninvasive Stellate Ganglion Blockade Performed Using Physical Agent Modalities in Patients with Sympathetic Hyperactivity-Associated Disorders: A Systematic Review and Meta-Analysis

    OpenAIRE

    Liao, Chun-De; Tsauo, Jau-Yih; Liou, Tsan-Hon; Chen, Hung-Chou; Rau, Chi-Lun

    2016-01-01

    Background Stellate ganglion blockade (SGB) is mainly used to relieve symptoms of neuropathic pain in conditions such as complex regional pain syndrome and has several potential complications. Noninvasive SGB performed using physical agent modalities (PAMs), such as light irradiation and electrical stimulation, can be clinically used as an alternative to conventional invasive SGB. However, its application protocols vary and its clinical efficacy remains controversial. This study investigated ...

  4. On Modal Refinement and Consistency

    DEFF Research Database (Denmark)

    Nyman, Ulrik; Larsen, Kim Guldstrand; Wasowski, Andrzej

    2007-01-01

    Almost 20 years after the original conception, we revisit several fundamental question about modal transition systems. First, we demonstrate the incompleteness of the standard modal refinement using a counterexample due to Hüttel. Deciding any refinement, complete with respect to the standard...

  5. Krull dimension in modal logic

    NARCIS (Netherlands)

    Bezhanishvili, G.; Bezhanishvili, N.; Lucero-Bryan, J.; van Mill, J.

    2017-01-01

    We develop the theory of Krull dimension for S4-algebras and Heyting algebras. This leads to the concept of modal Krull dimension for topological spaces. We compare modal Krull dimension to other well-known dimension functions, and show that it can detect differences between topological spaces that

  6. Modal Logics for Cryptographic Processes

    DEFF Research Database (Denmark)

    Frendrup, U.; Huttel, Hans; Jensen, N. J.

    2002-01-01

    We present three modal logics for the spi-calculus and show that they capture strong versions of the environment sensitive bisimulation introduced by Boreale et al. Our logics differ from conventional modal logics for process calculi in that they allow us to describe the knowledge of an attacker ...

  7. Operational modal analysis of a large wind turbine%大型风力机系统运行模态分析研究

    Institute of Scientific and Technical Information of China (English)

    钟灿堂; 李德源; 汪显能; 莫文威; 刘雄

    2016-01-01

    Aiming at the vibration modes and its variation characteristics of a large wind turbine under static status and various rotational speeds,the variations of each mode caused by elastic deformation,inertia and gyroscopic effect and their effects on aeroelastic stability of the wind turbine system were studied.Considering the large wind turbine system's non-linear characteristics and time-varying characteristics caused by the rotational wind rotor,the linear eigenvalue problems of the wind turbine were analyzed by using the dynamics software ADAMS,based on the dynamics theory of multi-body system and the modeling methodology of hybrid multi-body system (HMBS).A stiff integral method was then employed to solve the non-linear control equations of the system numerically considering the elastic deformation of flexible components and the rotation of the wind rotor.The operational modal identification was performed through Fourier spectral analysis.The variations of the system's first ten modes and their influence factors were discussed and analyzed in detail. The results can be used as aeroelastic stability criteria,which offer an effective solution and analysis method to avoid resonance and improve operating efficiency of the wind turbine system.%针对大型风力机在风轮静止、变速转动下振动模态及变化特点,研究弹性变形、惯性及陀螺效应引起的系统各阶模态变化及对系统气弹稳定性影响。通过研究现有线性特征值分析方法,考虑大型风力机非线性特性及风轮转动所致系统时变特性,基于多体系统动力学理论及混合多体系统 HMBS(Hybrid Multi-body Systems)建模方法,结合动力学分析软件 ADAMS,分析静止状态整机系统线性特征值问题;考虑构件弹性变形及风轮旋转,用刚性积分方法对系统非线性控制方程进行数值求解,通过傅里叶谱分析方法实现风轮旋转下系统运转模态识别,并讨论、分析系统前十

  8. Multi modal child-to-child interaction

    DEFF Research Database (Denmark)

    Fisker, Tine Basse

    In this presentation the interaction and relation of three boys is analyzed using multi modal analysis. The analysis clearly, and surprisingly demonstrates that the boys interact via different modes and that they are able to handle several interaction partners at the same time. They co......-construct interaction in rather complex and unexpected ways using verbal as well as non-verbal modes in interaction....

  9. Gap Flows through Idealized Topography. Part I: Forcing by Large-Scale Winds in the Nonrotating Limit.

    Science.gov (United States)

    Gabersek, Sasa.; Durran, Dale R.

    2004-12-01

    Gap winds produced by a uniform airstream flowing over an isolated flat-top ridge cut by a straight narrow gap are investigated by numerical simulation. On the scale of the entire barrier, the proportion of the oncoming flow that passes through the gap is relatively independent of the nondimensional mountain height , even over that range of for which there is the previously documented transition from a “flow over the ridge” regime to a “flow around” regime.The kinematics and dynamics of the gap flow itself were investigated by examining mass and momentum budgets for control volumes at the entrance, central, and exit regions of the gap. These analyses suggest three basic behaviors: the linear regime (small ) in which there is essentially no enhancement of the gap flow; the mountain wave regime ( 1.5) in which vertical mass and momentum fluxes play a crucial role in creating very strong winds near the exit of the gap; and the upstream-blocking regime ( 5) in which lateral convergence generates the strongest winds near the entrance of the gap.Trajectory analysis of the flow in the strongest events, the mountain wave events, confirms the importance of net subsidence in creating high wind speeds. Neglect of vertical motion in applications of Bernoulli's equation to gap flows is shown to lead to unreasonable wind speed predictions whenever the temperature at the gap exit exceeds that at the gap entrance. The distribution of the Bernoulli function on an isentropic surface shows a correspondence between regions of high Bernoulli function and high wind speeds in the gap-exit jet similar to that previously documented for shallow-water flow.

  10. Model Design of Piezoelectric Micromachined Modal Gyroscope

    Directory of Open Access Journals (Sweden)

    Xiaojun Hu

    2011-01-01

    Full Text Available This paper reports a novel kind of solid-state microgyroscope, which is called piezoelectric micromachined modal gyroscope (PMMG. PMMG has large stiffness and robust resistance to shake and strike because there is no evident mass-spring component in its structure. This work focused on quantitative optimization of the gyroscope, which is still blank for such gyroscope. The modal analysis by the finite element method (FEM was firstly conducted. A set of quantitative indicators were developed to optimize the operation mode. By FEM, the harmonic analysis was conducted to find the way to efficiently actuate the operational mode needed. The optimal configuration of driving electrodes was obtained. At last, the Coriolis analysis was conducted to show the relation between angular velocity and differential output voltage by the Coriolis force under working condition. The results obtained in this paper provide theoretical basis for realizing this novel kind of micromachined gyroscope.

  11. Nonrotating and slowly rotating holes

    International Nuclear Information System (INIS)

    Macdonald, D.A.; Price, R.H.; Thorne, K.S.; Suen, W.M.

    1986-01-01

    The 3+1 formalism is applied to model Schwarzschild spacetime around a black hole. Particular note is taken of the 3+1 split of the laws of electrodynamics, and of the tendency of the approach to freeze motion at the event horizon. The null horizon is replaced with a timelike physical membrane which exhibits mechanical, thermodynamic and electrical properties, and which stretches the horizon. The usefulness of the stretching approach is illustrated by considering a black hole penetrated by vibrating magnetic field lines anchored in a perfectly conducting surrounding sphere. The necessity of modeling the field structure near the actual horizon is avoided by having the field end at the membrane. The surface charge, current, resistivity and ohmic heating of the stretched horizon are also considered, and the Lorentz force imparted to the stretched horizon surface by the field lines is investigated by examining a nearly Schwarzschild hole behaving as the rotor of an electric motor

  12. A Causal Theory of Modality

    Directory of Open Access Journals (Sweden)

    José Tomás Alvarado

    2009-08-01

    Full Text Available This work presents a causal conception of metaphysical modality in which a state of affairs is metaphysically possible if and only if it can be caused (in the past, the present or the future by current entities. The conception is contrasted with what is called the “combinatorial” conception of modality, in which everything can co-exist with anything else. This work explains how the notion of ‘causality’ should be construed in the causal theory, what difference exists between modalities thus defined from nomological modality, how accessibility relations between possible worlds should be interpreted, and what is the relation between the causal conception and the necessity of origin.

  13. TU-FG-201-03: Automatic Pre-Delivery Verification Using Statistical Analysis of Consistencies in Treatment Plan Parameters by the Treatment Site and Modality

    International Nuclear Information System (INIS)

    Liu, S; Wu, Y; Chang, X; Li, H; Yang, D

    2016-01-01

    Purpose: A novel computer software system, namely APDV (Automatic Pre-Delivery Verification), has been developed for verifying patient treatment plan parameters right prior to treatment deliveries in order to automatically detect and prevent catastrophic errors. Methods: APDV is designed to continuously monitor new DICOM plan files on the TMS computer at the treatment console. When new plans to be delivered are detected, APDV checks the consistencies of plan parameters and high-level plan statistics using underlying rules and statistical properties based on given treatment site, technique and modality. These rules were quantitatively derived by retrospectively analyzing all the EBRT treatment plans of the past 8 years at authors’ institution. Therapists and physicists will be notified with a warning message displayed on the TMS computer if any critical errors are detected, and check results, confirmation, together with dismissal actions will be saved into database for further review. Results: APDV was implemented as a stand-alone program using C# to ensure required real time performance. Mean values and standard deviations were quantitatively derived for various plan parameters including MLC usage, MU/cGy radio, beam SSD, beam weighting, and the beam gantry angles (only for lateral targets) per treatment site, technique and modality. 2D-based rules of combined MU/cGy ratio and averaged SSD values were also derived using joint probabilities of confidence error ellipses. The statistics of these major treatment plan parameters quantitatively evaluate the consistency of any treatment plans which facilitates automatic APDV checking procedures. Conclusion: APDV could be useful in detecting and preventing catastrophic errors immediately before treatment deliveries. Future plan including automatic patient identify and patient setup checks after patient daily images are acquired by the machine and become available on the TMS computer. This project is supported by the

  14. TU-FG-201-03: Automatic Pre-Delivery Verification Using Statistical Analysis of Consistencies in Treatment Plan Parameters by the Treatment Site and Modality

    Energy Technology Data Exchange (ETDEWEB)

    Liu, S; Wu, Y; Chang, X; Li, H; Yang, D [Washington University School of Medicine, St. Louis, MO (United States)

    2016-06-15

    Purpose: A novel computer software system, namely APDV (Automatic Pre-Delivery Verification), has been developed for verifying patient treatment plan parameters right prior to treatment deliveries in order to automatically detect and prevent catastrophic errors. Methods: APDV is designed to continuously monitor new DICOM plan files on the TMS computer at the treatment console. When new plans to be delivered are detected, APDV checks the consistencies of plan parameters and high-level plan statistics using underlying rules and statistical properties based on given treatment site, technique and modality. These rules were quantitatively derived by retrospectively analyzing all the EBRT treatment plans of the past 8 years at authors’ institution. Therapists and physicists will be notified with a warning message displayed on the TMS computer if any critical errors are detected, and check results, confirmation, together with dismissal actions will be saved into database for further review. Results: APDV was implemented as a stand-alone program using C# to ensure required real time performance. Mean values and standard deviations were quantitatively derived for various plan parameters including MLC usage, MU/cGy radio, beam SSD, beam weighting, and the beam gantry angles (only for lateral targets) per treatment site, technique and modality. 2D-based rules of combined MU/cGy ratio and averaged SSD values were also derived using joint probabilities of confidence error ellipses. The statistics of these major treatment plan parameters quantitatively evaluate the consistency of any treatment plans which facilitates automatic APDV checking procedures. Conclusion: APDV could be useful in detecting and preventing catastrophic errors immediately before treatment deliveries. Future plan including automatic patient identify and patient setup checks after patient daily images are acquired by the machine and become available on the TMS computer. This project is supported by the

  15. Modal Auxiliaries and Their Semantic Functions Used by Advanced EFL Learners

    Science.gov (United States)

    Torabiardakani, Najmeh; Khojasteh, Laleh; Shokrpour, Nasrin

    2015-01-01

    Since modal auxiliary verbs have been proved to be one of the most troublesome grammatical structures in English, the researchers of this study decided to do an analysis on the ways in which advanced EFL Iranian students use modal auxiliaries focusing specially on nine modals' semantic functions. Consequently, was conducted based on the following…

  16. MPUQ-b: Bootstrapping Based Modal Parameter Uncertainty Quantification—Fundamental Principles

    DEFF Research Database (Denmark)

    Chauhan, S.; Ahmed, S. I.

    2017-01-01

    It is well known that modal parameters play a key role towards understanding the dynamics of a structure. Their estimation, by means of experiments, forms the crux of modal analysis. Modal parameters not only help in characterizing the dynamics of the structure but are also used for several other...

  17. Brazilian social management modalities

    Directory of Open Access Journals (Sweden)

    Maria Tereza Gonçalves

    2015-12-01

    Full Text Available In Brazil the social management is configured in a complex process. This is due to its asymmetry with respect to economic policy, environmental policy and. Social management is a major challenge that involves the articulation of warranty rights, expanding the notion of social development, the role of the state and the search for a management paradigm that respects the new status given to the social area . The analysis focuses on the methods of social management in Brazil. Among the findings it is noted that the management models adopted in Brazil has proved insufficient. It is also noted that the ideas produced around a democratic-participative management creates tensions in the hegemony of the managerial organization in the country, so that tension may represent a potentiation between efficiency and democracy.

  18. Fluoroscopic-guided radiofrequency ablation of the basivertebral nerve: application and analysis with multiple imaging modalities in an ovine model (Invited Paper)

    Science.gov (United States)

    Bergeron, Jeffrey A.; Eskey, Cliff J.; Attawia, Mohammed; Patel, Samit J.; Ryan, Thomas P.; Pellegrino, Richard; Sutton, Jeffrey; Crombie, John; Paul, B. T.; Hoopes, P. J.

    2005-04-01

    Pathologic involvement of the basivertebral nerve, an intraosseous vertebral nerve found in humans and most mammalian species, may play a role in some forms of back pain. This study was designed to assess the feasibility and effects of the percutaneous delivery of radiofrequency (RF) energy to thermally ablate the basivertebral nerve in the lumbar vertebrae of mature sheep. Using fluoroscopic guidance, a RF bipolar device was placed and a thermal dose delivered to lumbar vertebral bodies in sheep. Post-treatment assessment included multiple magnetic resonance imaging (MRI) techniques and computed tomography (CT). These data were analyzed and correlated to histopathology and morphometry findings to describe the cellular and boney structural changes resulting from the treatment. Imaging modalities MRI and CT can be implemented to non-invasively describe treatment region and volume, marrow cellular effects, and bone density alterations immediately following RF treatment and during convalescence. Such imaging can be utilized to assess treatment effects and refine the thermal dose to vertebral body volume ratio used in treatment planning. This information will be used to improve the therapeutic ratio and develop a treatment protocol for human applications.

  19. The modal transfer analysis by adding transport costs. Case study: The use of bus and private vehicle student Institut Teknologi Sumatera

    Science.gov (United States)

    Muliarto, H.; Alhamidi; Syahbandi, M.

    2017-06-01

    Since the last two years the Institut Teknologi Sumatera to accept new students in large numbers. Increasing the number of students is directly proportional to the increase of private vehicles that enter the campus it is not in line with the policy of the Institut Teknologi Sumatera as Smart, Friendly, and Forest Campus. Institut Teknologi Sumatera as Smart, Friendly, and Forest Campus fact has made some deal with mass public transport, Damri, to provide bus transportation to the Institut Teknologi Sumatera, but the number of bus users is still inferior to the number of private vehicle users. This study was conducted to see the modal transfer of the entire academic community ITERA, from private cars to public transport such as buses, with the addition of transportation costs in the form of parking rates. This study shows the dominant displacement can occur if the respondent charged parking fees of IDR 4.000. Besides the displacement mode of transportation from using private vehicles be using the bus can occur if Trans Lampung fix three systems including bus departure and arrival schedules, facility service providers that support, and the addition of the Bus Trans Lampung.

  20. Kajian Eksperimental Parameter Modal Bangunan Dua Lantai dengan Metode Modal Analisis

    Directory of Open Access Journals (Sweden)

    Islahuddin Islahuddin

    2016-12-01

    transformedin a FRF graph. FRF will then be processed in order to get structure mode shape. From the shape mode, analysis of themachine damage by looking at save amplitude value may be done. The purpose of this research is analyzing thedynamic character of vibration behavior on the structure model of two floor building. The testing is carried out byimplementing excitation force by using impact hammer. Accelerometer is used to measure structure vibrate signal. Theposition of accelerometer is variety for every eight different testing area. Meanwhile, the position of excitation force isthe same for all area of testing. This research applied experimental analysis modal method in order to identify dynamiccharacteristic of the structure model of two floor building. The aims of analysis modal technique are getting the modalparameter such as frequency, damping ratio, and mode shapes. The result of this research is the first natural frequencyon the maximum amplitude is the same of 2,313 Hz. While, for the second natural frequency on the maximum amplitudeis different on area 3 and area 7. This happened as the effect of the differences of excitation force in the testing area.Keywords: Dynamic characteristic, experimental modal analysis, natural frequency, FRF

  1. Modal noise impact in radio over fiber multimode fiber links.

    Science.gov (United States)

    Gasulla, I; Capmany, J

    2008-01-07

    A novel analysis is given on the statistics of modal noise for a graded-index multimode fiber (MMF) link excited by an analog intensity modulated laser diode. We present the speckle contrast as a function of the power spectrum of the modulated source and the transfer function of the MMF which behaves as an imperfect transversal microwave photonic filter. The theoretical results confirm that the modal noise is directly connected with the coherence properties of the optical source and show that the performance of high-frequency Radio Over Fiber (ROF) transmission through MMF links for short and middle reach distances is not substantially degraded by modal noise.

  2. Modalities in homotopy type theory

    DEFF Research Database (Denmark)

    Rijke, Egbert; Shulman, Michael; Spitters, Bas

    2017-01-01

    Univalent homotopy type theory (HoTT) may be seen as a language for the category of ∞-groupoids. It is being developed as a new foundation for mathematics and as an internal language for (elementary) higher toposes. We develop the theory of factorization systems, reflective subuniverses......, and modalities in homotopy type theory, including their construction using a "localization" higher inductive type. This produces in particular the (n-connected, n-truncated) factorization system as well as internal presentations of subtoposes, through lex modalities. We also develop the semantics...

  3. Linear contextual modal type theory

    DEFF Research Database (Denmark)

    Schack-Nielsen, Anders; Schürmann, Carsten

    Abstract. When one implements a logical framework based on linear type theory, for example the Celf system [?], one is immediately con- fronted with questions about their equational theory and how to deal with logic variables. In this paper, we propose linear contextual modal type theory that gives...... a mathematical account of the nature of logic variables. Our type theory is conservative over intuitionistic contextual modal type theory proposed by Nanevski, Pfenning, and Pientka. Our main contributions include a mechanically checked proof of soundness and a working implementation....

  4. TESS Lens-Bezel Assembly Modal Testing

    Science.gov (United States)

    Dilworth, Brandon J.; Karlicek, Alexandra

    2017-01-01

    The Transiting Exoplanet Survey Satellite (TESS) program, led by the Kavli Institute for Astrophysics and Space Research at the Massachusetts Institute of Technology (MIT) will be the first-ever spaceborne all-sky transit survey. MIT Lincoln Laboratory is responsible for the cameras, including the lens assemblies, detector assemblies, lens hoods, and camera mounts. TESS is scheduled to be launched in August of 2017 with the primary goal to detect small planets with bright host starts in the solar neighborhood, so that detailed characterizations of the planets and their atmospheres can be performed. The TESS payload consists of four identical cameras and a data handling unit. Each camera consists of a lens assembly with seven optical elements and a detector assembly with four charge-coupled devices (CCDs) including their associated electronics. The optical prescription requires that several of the lenses are in close proximity to a neighboring element. A finite element model (FEM) was developed to estimate the relative deflections between each lens-bezel assembly under launch loads to predict that there are adequate clearances preventing the lenses from making contact. Modal tests using non-contact response measurements were conducted to experimentally estimate the modal parameters of the lens-bezel assembly, and used to validate the initial FEM assumptions. Key Words Non-contact measurements, modal analysis, model validation

  5. Identification of Nasal Bone Fractures on Conventional Radiography and Facial CT: Comparison of the Diagnostic Accuracy in Different Imaging Modalities and Analysis of Interobserver Reliability

    International Nuclear Information System (INIS)

    Baek, Hye Jin; Kim, Dong Wook; Ryu, Ji Hwa; Lee, Yoo Jin

    2013-01-01

    There has been no study to compare the diagnostic accuracy of an experienced radiologist with a trainee in nasal bone fracture. To compare the diagnostic accuracy between conventional radiography and computed tomography (CT) for the identification of nasal bone fractures and to evaluate the interobserver reliability between a staff radiologist and a trainee. A total of 108 patients who underwent conventional radiography and CT after acute nasal trauma were included in this retrospective study. Two readers, a staff radiologist and a second-year resident, independently assessed the results of the imaging studies. Of the 108 patients, the presence of a nasal bone fracture was confirmed in 88 (81.5%) patients. The number of non-depressed fractures was higher than the number of depressed fractures. In nine (10.2%) patients, nasal bone fractures were only identified on conventional radiography, including three depressed and six non-depressed fractures. CT was more accurate as compared to conventional radiography for the identification of nasal bone fractures as determined by both readers (P <0.05), all diagnostic indices of an experienced radiologist were similar to or higher than those of a trainee, and κ statistics showed moderate agreement between the two diagnostic tools for both readers. There was no statistical difference in the assessment of interobserver reliability for both imaging modalities in the identification of nasal bone fractures. For the identification of nasal bone fractures, CT was significantly superior to conventional radiography. Although a staff radiologist showed better values in the identification of nasal bone fracture and differentiation between depressed and non-depressed fractures than a trainee, there was no statistically significant difference in the interpretation of conventional radiography and CT between a radiologist and a trainee

  6. The modal logic of forcing

    NARCIS (Netherlands)

    Hamkins, J.D.; Löwe, B.

    2008-01-01

    A set theoretical assertion psi is forceable or possible, written lozenge psi, if psi holds in some forcing extension, and necessary, written square psi, if psi holds in all forcing extensions. In this forcing interpretation of modal logic, we establish that if ZFC is consistent, then the

  7. Integration of Multi-Modal Biomedical Data to Predict Cancer Grade and Patient Survival.

    Science.gov (United States)

    Phan, John H; Hoffman, Ryan; Kothari, Sonal; Wu, Po-Yen; Wang, May D

    2016-02-01

    The Big Data era in Biomedical research has resulted in large-cohort data repositories such as The Cancer Genome Atlas (TCGA). These repositories routinely contain hundreds of matched patient samples for genomic, proteomic, imaging, and clinical data modalities, enabling holistic and multi-modal integrative analysis of human disease. Using TCGA renal and ovarian cancer data, we conducted a novel investigation of multi-modal data integration by combining histopathological image and RNA-seq data. We compared the performances of two integrative prediction methods: majority vote and stacked generalization. Results indicate that integration of multiple data modalities improves prediction of cancer grade and outcome. Specifically, stacked generalization, a method that integrates multiple data modalities to produce a single prediction result, outperforms both single-data-modality prediction and majority vote. Moreover, stacked generalization reveals the contribution of each data modality (and specific features within each data modality) to the final prediction result and may provide biological insights to explain prediction performance.

  8. Importance of modal cross-correlations on wind loaded structures

    OpenAIRE

    Denoël, Vincent; Degée, Hervé; De Ville De Goyet, Vincent

    2006-01-01

    In civil engineering applications the dynamic analysis of large structure is often performed in a modal space. This method is known to offer an interesting decrease of the number of degrees of freedom as well as a decomposition of the structure’s response in “uncoupled” components. Even if the response in each mode can be computed independently from the responses in the other ones, in the context of stochastic loading, the coherence of these modal responses must be accounted fo...

  9. LITERATURE REVIEW OF ELECTROMAGNETIC ACTUATOR FORCE GENERATION FOR DYNAMIC MODAL TESTING APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Norlida Jamil

    2012-12-01

    Full Text Available Milling is one of the most common manufacturing processes for automotive components, but its productivity is limited by the onset of regenerative chatter. This is a form of unstable self-excited vibration that occurs when the volume of material removed is too large for a particular spindle speed. This form of chatter is undesirable because it results in premature tool wear, poor surface finish on the machined component and the possibility of serious damage to the machine itself. The chatter stability of a milling process can be determined using well-established theory, provided that the frequency response of the flexible structure can be determined. In practice this usually involves the excitation of a stationery (non-rotating milling tool with a modal hammer, and measurement of the response of the tool with a co-located accelerometer. However, this measurement is not necessarily accurate due to amplitude dependency factor consideration. There is anecdotal evidence that structural nonlinearity can have a significant effect on the chatter stability of some milling machines. This project develops non-contact electromagnetic actuators to measure the frequency response of milling tools to machine automotive parts. In addition it will describe the practical application of this approach, and discuss its amplitude dependency for current excitation during frequency response function measurement using magnetic force generation.

  10. Analysis of nocturia with 24-h urine volume, nocturnal urine volume, nocturnal bladder capacity and length of sleep duration: concept for effective treatment modality.

    Science.gov (United States)

    Udo, Yukihiro; Nakao, Masahiro; Honjo, Hisashi; Ukimura, Osamu; Kawauchi, Akihiro; Kitakoji, Hiroshi; Miki, Tsuneharu

    2011-03-01

    with nocturnal polyuria and both long sleep duration and nocturnal polyuria. • Because nocturia is a multifactorial disorder and closely related to four factors (i.e. 24-h urine volume, nocturnal urine volume, nocturnal bladder capacity and length of sleep duration), the evaluation of all these factors appears to be clinically useful for determining the main contributing factor in patients with nocturia as well as the suitable treatment modality on an individual basis. • Physicians should take all these factors into consideration in the evaluation and treatment of nocturia. © 2010 THE AUTHORS. JOURNAL COMPILATION © 2010 BJU INTERNATIONAL.

  11. Modal decomposition without a priori scale information

    CSIR Research Space (South Africa)

    Schulze, C

    2012-12-01

    Full Text Available , and A. Friberg, ?Transverse laser mode structure determination from spatial coherence measurements: Experimental results,? Appl. Phys. B. 49, 409?414 (1989). 4. A. Cutolo, T. Isernia, I. Izzo, R. Pierri, and L. Zeni, ?Transverse mode analysis of a... laser beam by near-and far-field intensity measurements,? Appl. Opt. 34, 7974?7978 (1995). 5. M. Santarsiero, F. Gori, R. Borghi, and G. Guattari, ?Evaluation of the modal structure of light beams composed of incoherent mixtures of hermite...

  12. Modal Based Fatigue Monitoring of Steel Structures

    DEFF Research Database (Denmark)

    Graugaard-Jensen, J.; Brincker, Rune; Hjelm, H. P.

    2005-01-01

    In this paper it is shown how the accumulated fatigue in steel structures can be estimated with high accuracy by continuously measuring the accelerations in a few points of the structure. First step is to obtain a good estimate of the mode shapes by performing a natural input modal analysis. The so...... by applying the mode shapes of the calibrated Finite Element model and strains are obtained using the shape functions for the actual elements. The technique has been applied on a model frame structure in the laboratory and on a wind loaded lattice pylon structure. In both cases the estimated stresses has been...

  13. Stimulus Modality and Smoking Behavior: Moderating Role of Implicit Attitudes.

    Science.gov (United States)

    Ezeh, Valentine C; Mefoh, Philip

    2015-07-20

    This study investigated whether stimulus modality influences smoking behavior among smokers in South Eastern Nigeria and also whether implicit attitudes moderate the relationship between stimulus modality and smoking behavior. 60 undergraduate students of University of Nigeria, Nsukka were used. Participants were individually administered the IAT task as a measure of implicit attitude toward smoking and randomly assigned into either image condition that paired images of cigarette with aversive images of potential health consequences or text condition that paired images of cigarette with aversive texts of potential health consequences. A one- predictor and one-moderator binary logistic analysis indicates that stimulus modality significantly predicts smoking behavior (p = smoke with greater probability than the text condition. The interaction between stimulus modality and IAT scores was also significant (p = attitudes towards smoking. The finding shows the urgent need to introduce the use of aversive images of potential health consequences on cigarette packs in Nigeria.

  14. Statistical approach for uncertainty quantification of experimental modal model parameters

    DEFF Research Database (Denmark)

    Luczak, M.; Peeters, B.; Kahsin, M.

    2014-01-01

    Composite materials are widely used in manufacture of aerospace and wind energy structural components. These load carrying structures are subjected to dynamic time-varying loading conditions. Robust structural dynamics identification procedure impose tight constraints on the quality of modal models...... represent different complexity levels ranging from coupon, through sub-component up to fully assembled aerospace and wind energy structural components made of composite materials. The proposed method is demonstrated on two application cases of a small and large wind turbine blade........ This paper aims at a systematic approach for uncertainty quantification of the parameters of the modal models estimated from experimentally obtained data. Statistical analysis of modal parameters is implemented to derive an assessment of the entire modal model uncertainty measure. Investigated structures...

  15. Mixing Categories and Modal Logics in the Quantum Setting

    Science.gov (United States)

    Cinà, Giovanni

    The study of the foundations of Quantum Mechanics, especially after the advent of Quantum Computation and Information, has benefited from the application of category-theoretic tools and modal logics to the analysis of Quantum processes: we witness a wealth of theoretical frameworks casted in either of the two languages. This paper explores the interplay of the two formalisms in the peculiar context of Quantum Theory. After a review of some influential abstract frameworks, we show how different modal logic frames can be extracted from the category of finite dimensional Hilbert spaces, connecting the Categorical Quantum Mechanics approach to some modal logics that have been proposed for Quantum Computing. We then apply a general version of the same technique to two other categorical frameworks, the `topos approach' of Doering and Isham and the sheaf-theoretic work on contextuality by Abramsky and Brandenburger, suggesting how some key features can be expressed with modal languages.

  16. Quantum supports and modal logic

    International Nuclear Information System (INIS)

    Svetlichny, G.

    1986-01-01

    Recently Foulis, Piron, and Randall introduced a new interpretation of empirical and quantum logics which substitute for the notion of a probabilistic weight a combinatorial notion called a support. The informal use of the notion of ''possible outcomes of experiments'' suggests that this interpretation can be related to corresponding formal notions as treated by modal logic. The purpose of this paper is to prove that in fact supports are in one-to-one correspondence with the sets of possibly true elementary propositions in Kripke models of a set of modal formulas associated to the empirical or quantum logic. This hopefully provides a sufficiently detailed link between the two rather distinct logical systems to shed useful light on both

  17. Modal abstractions of concurrent behavior

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nanz, Sebastian; Nielson, Hanne Riis

    2011-01-01

    We present an effective algorithm for the automatic construction of finite modal transition systems as abstractions of potentially infinite concurrent processes. Modal transition systems are recognized as valuable abstractions for model checking because they allow for the validation as well...... as refutation of safety and liveness properties. However, the algorithmic construction of finite abstractions from potentially infinite concurrent processes is a missing link that prevents their more widespread usage for model checking of concurrent systems. Our algorithm is a worklist algorithm using concepts...... from abstract interpretation and operating upon mappings from sets to intervals in order to express simultaneous over- and underapprox-imations of the multisets of process actions available in a particular state. We obtain a finite abstraction that is 3-valued in both states and transitions...

  18. Modality-specificity of Selective Attention Networks.

    Science.gov (United States)

    Stewart, Hannah J; Amitay, Sygal

    2015-01-01

    To establish the modality specificity and generality of selective attention networks. Forty-eight young adults completed a battery of four auditory and visual selective attention tests based upon the Attention Network framework: the visual and auditory Attention Network Tests (vANT, aANT), the Test of Everyday Attention (TEA), and the Test of Attention in Listening (TAiL). These provided independent measures for auditory and visual alerting, orienting, and conflict resolution networks. The measures were subjected to an exploratory factor analysis to assess underlying attention constructs. The analysis yielded a four-component solution. The first component comprised of a range of measures from the TEA and was labeled "general attention." The third component was labeled "auditory attention," as it only contained measures from the TAiL using pitch as the attended stimulus feature. The second and fourth components were labeled as "spatial orienting" and "spatial conflict," respectively-they were comprised of orienting and conflict resolution measures from the vANT, aANT, and TAiL attend-location task-all tasks based upon spatial judgments (e.g., the direction of a target arrow or sound location). These results do not support our a-priori hypothesis that attention networks are either modality specific or supramodal. Auditory attention separated into selectively attending to spatial and non-spatial features, with the auditory spatial attention loading onto the same factor as visual spatial attention, suggesting spatial attention is supramodal. However, since our study did not include a non-spatial measure of visual attention, further research will be required to ascertain whether non-spatial attention is modality-specific.

  19. Modality-specificity of selective attention networks

    Directory of Open Access Journals (Sweden)

    Hannah Jamieson Stewart

    2015-11-01

    Full Text Available Objective: To establish the modality specificity and generality of selective attention networks. Method: Forty-eight young adults completed a battery of four auditory and visual selective attention tests based upon the Attention Network framework: the visual and auditory Attention Network Tests (vANT, aANT, the Test of Everyday Attention (TEA, and the Test of Attention in Listening (TAiL. These provided independent measures for auditory and visual alerting, orienting, and conflict resolution networks. The measures were subjected to an exploratory factor analysis to assess underlying attention constructs. Results: The analysis yielded a four-component solution. The first component comprised of a range of measures from the TEA and was labeled ‘general attention’. The third component was labeled ‘auditory attention’, as it only contained measures from the TAiL using pitch as the attended stimulus feature. The second and fourth components were labeled as ‘spatial orienting’ and ‘spatial conflict’, respectively – they were comprised of orienting and conflict resolution measures from the vANT, aANT and TAiL attend-location task – all tasks based upon spatial judgments (e.g., the direction of a target arrow or sound location. Conclusions: These results do not support our a-priori hypothesis that attention networks are either modality specific or supramodal. Auditory attention separated into selectively attending to spatial and non-spatial features, with the auditory spatial attention loading onto the same factor as visual spatial attention, suggesting spatial attention is supramodal. However, since our study did not include a non-spatial measure of visual attention, further research will be required to ascertain whether non-spatial attention is modality-specific.

  20. Modal coupling procedures adapted to NASTRAN analysis of the 1/8-scale shuttle structural dynamics model. Volume 1: Technical report

    Science.gov (United States)

    Zalesak, J.

    1975-01-01

    A dynamic substructuring analysis, utilizing the component modes technique, of the 1/8 scale space shuttle orbiter finite element model is presented. The analysis was accomplished in 3 phases, using NASTRAN RIGID FORMAT 3, with appropriate Alters, on the IBM 360-370. The orbiter was divided into 5 substructures, each of which was reduced to interface degrees of freedom and generalized normal modes. The reduced substructures were coupled to yield the first 23 symmetric free-free orbiter modes, and the eigenvectors in the original grid point degree of freedom lineup were recovered. A comparison was made with an analysis which was performed with the same model using the direct coordinate elimination approach. Eigenvalues were extracted using the inverse power method.

  1. A modal characterization of Peirce algebras

    NARCIS (Netherlands)

    M. de Rijke (Maarten)

    1995-01-01

    textabstractPeirce algebras combine sets, relations and various operations linking the two in a unifying setting.This note offers a modal perspective on Peirce algebras.It uses modal logic to characterize the full Peirce algebras.

  2. Combined modalities: chemotherapy/radiotherapy. Meeting summary

    International Nuclear Information System (INIS)

    Phillips, T.L.

    1979-01-01

    The effects of combined modalities, the standardization of terminology, the mechanisms of chemotherapeutic interactions with radiation and responses of normal and tumor systems are summarized from information presented at the Conference on Combined Modalities

  3. Tailoring distributed modal sensors for in-plane modal filtering

    International Nuclear Information System (INIS)

    Donoso, A; Bellido, J C

    2009-01-01

    In this note we deal with finding the shape of distributed piezoelectric modal sensors for isolating the in-plane mode shapes of plates. The problem is treated by an optimization approach, in which a binary function is used to model the design variable: the polarization profile of the piezoelectric layer. The numerical procedure proposed here allows us to find polarization profiles which take on two values only, i.e. either positive or negative polarization, that make it possible to isolate particular vibration modes in the frequency domain. (technical note)

  4. Nondestructive Damage Assessment of Composite Structures Based on Wavelet Analysis of Modal Curvatures: State-of-the-Art Review and Description of Wavelet-Based Damage Assessment Benchmark

    Directory of Open Access Journals (Sweden)

    Andrzej Katunin

    2015-01-01

    Full Text Available The application of composite structures as elements of machines and vehicles working under various operational conditions causes degradation and occurrence of damage. Considering that composites are often used for responsible elements, for example, parts of aircrafts and other vehicles, it is extremely important to maintain them properly and detect, localize, and identify the damage occurring during their operation in possible early stage of its development. From a great variety of nondestructive testing methods developed to date, the vibration-based methods seem to be ones of the least expensive and simultaneously effective with appropriate processing of measurement data. Over the last decades a great popularity of vibration-based structural testing has been gained by wavelet analysis due to its high sensitivity to a damage. This paper presents an overview of results of numerous researchers working in the area of vibration-based damage assessment supported by the wavelet analysis and the detailed description of the Wavelet-based Structural Damage Assessment (WavStructDamAs Benchmark, which summarizes the author’s 5-year research in this area. The benchmark covers example problems of damage identification in various composite structures with various damage types using numerous wavelet transforms and supporting tools. The benchmark is openly available and allows performing the analysis on the example problems as well as on its own problems using available analysis tools.

  5. Bimodal extinction without cross-modal extinction.

    OpenAIRE

    Inhoff, A W; Rafal, R D; Posner, M J

    1992-01-01

    Three patients with unilateral neurological injury were clinically examined. All showed consistent unilateral extinction in the tactile and visual modalities on simultaneous intramodal stimulation. There was virtually no evidence for cross-modal extinction, however, so that contralateral stimulation of one modality would have extinguished perception of ipsilateral stimuli in the other modality. It is concluded that the attentional system controlling the encoding of tactile and visual stimuli ...

  6. Librarian instruction-delivery modality preferences for professional continuing education.

    Science.gov (United States)

    Lynn, Valerie A; Bose, Arpita; Boehmer, Susan J

    2010-01-01

    Attending professional continuing education (CE) is an important component of librarianship. This research study identified librarians' preferences in delivery modalities of instruction for professional CE. The study also identified influential factors associated with attending CE classes. Five instruction-delivery modalities and six influential factors were identified for inclusion in an online survey. The survey completed by members of the American Library Association (ALA), Special Libraries Association (SLA), and Medical Library Association (MLA) provided the data for analysis of librarian preferences and influential factors. The majority of respondents were MLA members, followed by ALA and SLA members. Librarians from all three library associations preferred the face-to-face instructional modality. The most influential factor associated with the decision to attend a professional CE class was cost. All five instruction-delivery modalities present useful structures for imparting professional CE. As librarians' experience with different modalities increases and as technology improves, preferences in instruction delivery may shift. But at present, face-to-face remains the most preferred modality. Based on the results of this study, cost was the most influential factor associated with attending a CE class. This may change as additional influential factors are identified and analyzed in future studies.

  7. Modular sequent calculi for classical modal logics

    NARCIS (Netherlands)

    Gilbert, David; Maffezioli, Paolo

    This paper develops sequent calculi for several classical modal logics. Utilizing a polymodal translation of the standard modal language, we are able to establish a base system for the minimal classical modal logic E from which we generate extensions (to include M, C, and N) in a modular manner. Our

  8. Completeness for flat modal fixpoint logics

    NARCIS (Netherlands)

    Santocanale, L.; Venema, Y.

    2010-01-01

    This paper exhibits a general and uniform method to prove axiomatic completeness for certain modal fixpoint logics. Given a set Γ of modal formulas of the form γ(x,p1,…,pn), where x occurs only positively in γ, we obtain the flat modal fixpoint language L♯(Γ) by adding to the language of polymodal

  9. Physical modalities in chronic pain management.

    Science.gov (United States)

    Rakel, Barbara; Barr, John O

    2003-09-01

    The following conclusions can be made based on review of the evidence: There is limited but positive evidence that select physical modalities are effective in managing chronic pain associated with specific conditions experienced by adults and older individuals. Overall, studies have provided the most support for the modality of therapeutic exercise. Different physical modalities have similar magnitudes of effects on chronic pain. Therefore, selection of the most appropriate physical modality may depend on the desired functional outcome for the patient, the underlying impairment, and the patient's preference or prior experience with the modality. Certain patient characteristics may decrease the effectiveness of physical modalities, as has been seen with TENS. These characteristics include depression, high trait anxiety, a powerful others locus of control, obesity, narcotic use, and neuroticism. The effect on pain by various modalities is generally strongest in the short-term period immediately after the intervention series, but effects can last as long as 1 year after treatment (e.g., with massage). Most research has tested the effect of physical modalities on chronic low back pain and knee OA. The effectiveness of physical modalities for other chronic pain conditions needs to be evaluated more completely. Older and younger adults often experience similar effects on their perception of pain from treatment with physical modalities. Therefore, use of these modalities for chronic pain in older adults is appropriate, but special precautions need to be taken. Practitioners applying physical modalities need formal training that includes the risks and precautions for these modalities. If practitioners lack formal training in the use of physical modalities, or if modality use is not within their scope of practice, it is important to consult with and refer patients to members of the team who have this specialized training. Use of a multidisciplinary approach to chronic pain

  10. To increase controllability of a large flexible antenna by modal optimization

    Science.gov (United States)

    Wang, Feng; Wang, Pengpeng; Jiang, Wenjian

    2017-12-01

    Large deployable antennas are widely used in aerospace engineering to meet the envelop limit of rocket fairing. The high flexibility and low damping of antenna has proposed critical requirement not only for stability control of the antenna itself, but also for attitude control of the satellite. This paper aims to increase controllability of a large flexible antenna by modal optimization. Firstly, Sensitivity analysis of antenna modal frequencies to stiffness of support structure and stiffness of scanning mechanism are conducted respectively. Secondly, Modal simulation results of antenna frequencies are given, influences of scanning angles on moment of inertia and modal frequencies are evaluated, and modal test is carried out to validate the simulation results. All the simulation and test results show that, after modal optimization the modal characteristic of the large deployable antenna meets the controllability requirement well.

  11. ANALISIS BELANJA MODAL, INVESTASI, DAN TENAGA KERJA TERHADAP PERTUMBUHAN EKONOMI SULAWESI SELATAN (CAPITAL EXPENDITURES ANALYSIS, INVESTMENTS, AND EMPLOYMENT ON ECONOMIC GROWTH SOUTH SULAWESI

    Directory of Open Access Journals (Sweden)

    Basri Bado

    2015-08-01

    Full Text Available The aim of this study was to determine the influence of Capital Expenditure and Investment, and Employment on economic growth in South Sulawesi. This study uses time series data (time series in 2001-2013. Data collected through observation and documentation. Data were analyzed using multiple linear regression analysis by the method of ordinary least squares (OLS. The results showed that the variable Capital Expenditures, Investment, and Labour significant effect on economic growth in South Sulawesi. Capital Expenditure Partially variables, and variables of Labor has a significant influence on the economic growth of South Sulawesi. While variable investments significantly negative effect on economic growth in South Sulawesi.

  12. STRUKTUR MODAL DAN MODAL KERJA PT XYZ SERTA PENGARUHNYA TERHADAP KINERJA PERUSAHAAN

    Directory of Open Access Journals (Sweden)

    Untung Setiono

    2017-01-01

    Full Text Available n 2012, the electronic payment system transactions reached IDR 104.830 trillion or increase 46,52% from the previous year.  PT. XYZ is the  pioneer in the electronic payment system Indonesia  and still one of the leading companies in electronic payment system interbank, through ATM (Automatic Teller Machine and EDC (Electronic Data Capture in Indonesia.  In 2012 the company spent USD 3,4 million on software tandem from a foreign vendor.  Therefore it is important to study (1 policy on the modal structure of the company, (2 the working capital policy of the company, (3 the monetary performance relationship of the company based on the 2 policies.  The method used to analyze the data is multiple linear regression analysis; this method is used to calculate the relationship between the structure variable of the capital and working capital.  The result is; 1 the structure policy on the capital of the company is in accordance with the Pecking Order theory where the company uses their own capital before applying the long term debt to the others, 2 the inefficient policy on the company’s working capital is because most of the active asset is in monthly deposit bonds and even extended  the active debt, 3 the relationship between short term debt and liquidity ratio is negative while the total debt (short and long term has a positive correlation with the solvability/leverage ratio of the company.  The research recommends the management to decrease the active asset and uses it for long term investment not only for timed deposit.Keywords:  ATM, EDC, capital structure, financial performance     AbstrakVoulme transaksi dalam menggunakan sistem pembayaran elektronis pada tahun 2012 mencapai Rp104.830 triliun atau meningkat sekitar 46,52% dari tahun sebelumnya. PT XYZ adalah salah satu perusahaan pionir dalam sistem bidang pembayaran elektronis di Indonesia dan tetap menjadi pemain utama dalam sistem pembayaran elektronis antar bank, ATM

  13. Simultaneous separation and analysis of water- and fat-soluble vitamins on multi-modal reversed-phase weak anion exchange material by HPLC-UV.

    Science.gov (United States)

    Dabre, Romain; Azad, Nazanin; Schwämmle, Achim; Lämmerhofer, Michael; Lindner, Wolfgang

    2011-04-01

    Several methods for the separation of vitamins on HPLC columns were already validated in the last 20 years. However, most of the techniques focus on separating either fat- or water-soluble vitamins and only few methods are intended to separate lipophilic and hydrophilic vitamins simultaneously. A mixed-mode reversed-phase weak anion exchange (RP-WAX) stationary phase was developed in our laboratory in order to address such mixture of analytes with different chemical characteristics, which are difficult to separate on standard columns. The high versatility in usage of the RP-WAX chromatographic material allowed a baseline separation of ten vitamins within a single run, seven water-soluble and three fat-soluble, using three different chromatographic modes: some positively charged vitamins are eluted in ion exclusion and ion repulsion modes whereas the negatively charged molecules are eluted in the ion exchange mechanism. The non-charged molecules are eluted in a classical reversed-phase mode, regarding their polarities. The method was validated for the vitamin analysis in tablets, evaluating selectivity, robustness, linearity, accuracy, and precision. The validated method was finally employed for the analysis of the vitamin content of some commercially available supplement tablets. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Modality and Task Switching Interactions using Bi-Modal and Bivalent Stimuli

    Science.gov (United States)

    Sandhu, Rajwant; Dyson, Benjamin J.

    2013-01-01

    Investigations of concurrent task and modality switching effects have to date been studied under conditions of uni-modal stimulus presentation. As such, it is difficult to directly compare resultant task and modality switching effects, as the stimuli afford both tasks on each trial, but only one modality. The current study investigated task and…

  15. Traces of 'Simple Psalmody' in late- and post-Byzantine musical manuscripts. Melodic, modal and textual analysis of the Kekragarion tradition

    DEFF Research Database (Denmark)

    Sanfratello, Giuseppe

    2017-01-01

    The study of the Kekragarion chant tradition has over time become an important aspect of Byzantine musicology, especially regarding the development of “simple psalmody”. Simple psalmody describes the functional side of Byzantine “psalm tones”, pointing out a set of recurrent behaviours in the ada......The study of the Kekragarion chant tradition has over time become an important aspect of Byzantine musicology, especially regarding the development of “simple psalmody”. Simple psalmody describes the functional side of Byzantine “psalm tones”, pointing out a set of recurrent behaviours......, but for the actual analysis two manuscripts representing the Kekragaria versions contained in the whole group of manuscripts were selected for transcription. My survey shows how the melodic tradition of the late medieval Kekragarion has been partly maintained and partly developed over four centuries, and it also...

  16. Quantitative Analysis of Diffusion-Weighted Imaging for Diagnosis of Puerperal Breast Abscess After Polyacrylamide Hydrogel Augmentation Mammoplasty: Compared with Other Conventional Modalities.

    Science.gov (United States)

    Liu, Lihua; Long, Miaomiao; Wang, Junping; Liu, Ning; Ge, Xihong; Hu, Zhandong; Shen, Wen

    2015-02-01

    Puerperal breast abscess after polyacrylamide hydrogel (PAAG) augmentation mammoplasty can induce breast auto-inflation resulting in serious consequences. Mammography, ultrasound, and conventional MRI are poor at detecting related PAAG abnormality histologically. We evaluated the value of diffusion-weighted imaging (DWI) in the quantitative analysis of puerperal PAAG abscess after augmentation mammoplasty. This was a retrospective study, and a waiver for informed consent was granted. Sixteen puerperal women with breast discomfort underwent conventional breast non-enhanced MRI and axial DWI using a 3T MR scanner. Qualitative analysis of the signal intensity on DWI and conventional sequences was performed. The apparent diffusion coefficient (ADC) values of the affected and contralateral normal PAAG cysts were measured quantitatively. Paired t test was used to evaluate whether there was significant difference. Both affected and normal PAAG cysts showed equal signal intensity on conventional T1WI and fat saturation T2WI, which were not helpful in detecting puerperal PAAG abscess. However, the affected PAAG cysts had a significantly decreased ADC value of 1.477 ± 0.332 × 10(-3)mm(2)/s and showed obvious hypo-intensity on the ADC map and increased signal intensity on DWI compared with the ADC value of 2.775 ± 0.233 × 10(-3)mm(2)/s of the contralateral normal PAAG cysts. DWI and quantitative measurement of ADC values are of great value for the diagnosis of puerperal PAAG abscess. Standardized MRI should be suggested to these puerperal women with breast discomfort or just for the purpose of check up. DWI should be selected as the essential MRI sequence.

  17. Aspirin as a potential modality for the chemoprevention of breast cancer: A dose-response meta-analysis of cohort studies from 857,831 participants.

    Science.gov (United States)

    Lu, Liming; Shi, Leiyu; Zeng, Jingchun; Wen, Zehuai

    2017-06-20

    Previous meta-analyses on the relationship between aspirin use and breast cancer risk have drawn inconsistent results. In addition, the threshold effect of different doses, frequencies and durations of aspirin use in preventing breast cancer have yet to be established. The search yielded 13 prospective cohort studies (N=857,831 participants) that reported an average of 7.6 cases/1,000 person-years of breast cancer during a follow-up period of from 4.4 to 14 years. With a random effects model, a borderline significant inverse association was observed between overall aspirin use and breast cancer risk, with a summarized RR = 0.94 (P = 0.051, 95% CI 0.87-1.01). The linear regression model was a better fit for the dose-response relationship, which displayed a potential relationship between the frequency of aspirin use and breast cancer risk (RR = 0.97, 0.95 and 0.90 for 5, 10 and 20 times/week aspirin use, respectively). It was also a better fit for the duration of aspirin use and breast cancer risk (RR = 0.86, 0.73 and 0.54 for 5, 10 and 20 years of aspirin use). We searched MEDLINE, EMBASE and CENTRAL databases through early October 2016 for relevant prospective cohort studies of aspirin use and breast cancer risk. Meta-analysis of relative risks (RR) estimates associated with aspirin intake were presented by fixed or random effects models. The dose-response meta-analysis was performed by linear trend regression and restricted cubic spline regression. Our study confirmed a dose-response relationship between aspirin use and breast cancer risk. For clinical prevention, long term (>5 years) consistent use (2-7 times/week) of aspirin appears to be more effective in achieving a protective effect against breast cancer.

  18. Multi-scale, multi-modal analysis uncovers complex relationship at the brain tissue-implant neural interface: new emphasis on the biological interface

    Science.gov (United States)

    Michelson, Nicholas J.; Vazquez, Alberto L.; Eles, James R.; Salatino, Joseph W.; Purcell, Erin K.; Williams, Jordan J.; Cui, X. Tracy; Kozai, Takashi D. Y.

    2018-06-01

    Objective. Implantable neural electrode devices are important tools for neuroscience research and have an increasing range of clinical applications. However, the intricacies of the biological response after implantation, and their ultimate impact on recording performance, remain challenging to elucidate. Establishing a relationship between the neurobiology and chronic recording performance is confounded by technical challenges related to traditional electrophysiological, material, and histological limitations. This can greatly impact the interpretations of results pertaining to device performance and tissue health surrounding the implant. Approach. In this work, electrophysiological activity and immunohistological analysis are compared after controlling for motion artifacts, quiescent neuronal activity, and material failure of devices in order to better understand the relationship between histology and electrophysiological outcomes. Main results. Even after carefully accounting for these factors, the presence of viable neurons and lack of glial scarring does not convey single unit recording performance. Significance. To better understand the biological factors influencing neural activity, detailed cellular and molecular tissue responses were examined. Decreases in neural activity and blood oxygenation in the tissue surrounding the implant, shift in expression levels of vesicular transporter proteins and ion channels, axon and myelin injury, and interrupted blood flow in nearby capillaries can impact neural activity around implanted neural interfaces. Combined, these tissue changes highlight the need for more comprehensive, basic science research to elucidate the relationship between biology and chronic electrophysiology performance in order to advance neural technologies.

  19. Establishment study of the in vivo imaging analysis with small animal imaging modalities (micro-PET and micro-SPECT/CT) for bio-drug development

    International Nuclear Information System (INIS)

    Jang, Beomsu; Park, Sanghyeon; Park, Jeonghoon; Jo, Sungkee; Jung, Uhee; Kim, Seolwha; Lee, Yunjong; Choi, Daeseong

    2011-01-01

    In this study, we established the image acquisition and analysis procedures of micro-PET, SPECT/CT using the experimental animal (mouse) for the development of imaging assessment method for the bio-drug. We examined the micro-SPECT/CT, PET imaging study using the Siemens Inveon micro-multimodality system (SPECT/CT) and micro-PET with 99m Tc-MDP, DMSA, and 18 F-FDG. SPECT imaging studies using 3 types of pinhole collimators. 5-MWB collimator was used for SPECT image study. To study whole-body distribution, 99m Tc-MDP SPECT image study was performed. We obtained the fine distribution image. And the CT images was obtained to provide the anatomical information. And then these two types images are fused. To study specific organ uptake, we examined 99 mTc-DMSA SPECT/CT imaging study. We also performed the PET image study using U87MG tumor bearing mice and 18 F-FDG. The overnight fasting, warming and anesthesia with 2% isoflurane pretreatment enhance the tumor image through reducing the background uptake including brown fat, harderian gland and skeletal muscles. Also we got the governmental approval for use of x-ray generator for CT and radioisotopes as sealed and open source. We prepared the draft of process procedure for the experimental animal imaging facility. These research results can be utilized as a basic image study protocols and data for the image assessment of drugs including biological drug

  20. Underdetermined Blind Audio Source Separation Using Modal Decomposition

    Directory of Open Access Journals (Sweden)

    Abdeldjalil Aïssa-El-Bey

    2007-03-01

    Full Text Available This paper introduces new algorithms for the blind separation of audio sources using modal decomposition. Indeed, audio signals and, in particular, musical signals can be well approximated by a sum of damped sinusoidal (modal components. Based on this representation, we propose a two-step approach consisting of a signal analysis (extraction of the modal components followed by a signal synthesis (grouping of the components belonging to the same source using vector clustering. For the signal analysis, two existing algorithms are considered and compared: namely the EMD (empirical mode decomposition algorithm and a parametric estimation algorithm using ESPRIT technique. A major advantage of the proposed method resides in its validity for both instantaneous and convolutive mixtures and its ability to separate more sources than sensors. Simulation results are given to compare and assess the performance of the proposed algorithms.

  1. Underdetermined Blind Audio Source Separation Using Modal Decomposition

    Directory of Open Access Journals (Sweden)

    Aïssa-El-Bey Abdeldjalil

    2007-01-01

    Full Text Available This paper introduces new algorithms for the blind separation of audio sources using modal decomposition. Indeed, audio signals and, in particular, musical signals can be well approximated by a sum of damped sinusoidal (modal components. Based on this representation, we propose a two-step approach consisting of a signal analysis (extraction of the modal components followed by a signal synthesis (grouping of the components belonging to the same source using vector clustering. For the signal analysis, two existing algorithms are considered and compared: namely the EMD (empirical mode decomposition algorithm and a parametric estimation algorithm using ESPRIT technique. A major advantage of the proposed method resides in its validity for both instantaneous and convolutive mixtures and its ability to separate more sources than sensors. Simulation results are given to compare and assess the performance of the proposed algorithms.

  2. Establishment study of the in vivo imaging analysis with small animal imaging modalities (micro-PET and micro-SPECT/CT) for bio-drug development

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Beomsu; Park, Sanghyeon; Park, Jeonghoon; Jo, Sungkee; Jung, Uhee; Kim, Seolwha; Lee, Yunjong; Choi, Daeseong

    2011-01-15

    In this study, we established the image acquisition and analysis procedures of micro-PET, SPECT/CT using the experimental animal (mouse) for the development of imaging assessment method for the bio-drug. We examined the micro-SPECT/CT, PET imaging study using the Siemens Inveon micro-multimodality system (SPECT/CT) and micro-PET with {sup 99m}Tc-MDP, DMSA, and {sup 18}F-FDG. SPECT imaging studies using 3 types of pinhole collimators. 5-MWB collimator was used for SPECT image study. To study whole-body distribution, {sup 99m}Tc-MDP SPECT image study was performed. We obtained the fine distribution image. And the CT images was obtained to provide the anatomical information. And then these two types images are fused. To study specific organ uptake, we examined {sup 99}mTc-DMSA SPECT/CT imaging study. We also performed the PET image study using U87MG tumor bearing mice and {sup 18}F-FDG. The overnight fasting, warming and anesthesia with 2% isoflurane pretreatment enhance the tumor image through reducing the background uptake including brown fat, harderian gland and skeletal muscles. Also we got the governmental approval for use of x-ray generator for CT and radioisotopes as sealed and open source. We prepared the draft of process procedure for the experimental animal imaging facility. These research results can be utilized as a basic image study protocols and data for the image assessment of drugs including biological drug.

  3. Autologous or reduced-intensity conditioning allogeneic hematopoietic cell transplantation for chemotherapy-sensitive mantle-cell lymphoma: analysis of transplantation timing and modality.

    Science.gov (United States)

    Fenske, Timothy S; Zhang, Mei-Jie; Carreras, Jeanette; Ayala, Ernesto; Burns, Linda J; Cashen, Amanda; Costa, Luciano J; Freytes, César O; Gale, Robert P; Hamadani, Mehdi; Holmberg, Leona A; Inwards, David J; Lazarus, Hillard M; Maziarz, Richard T; Munker, Reinhold; Perales, Miguel-Angel; Rizzieri, David A; Schouten, Harry C; Smith, Sonali M; Waller, Edmund K; Wirk, Baldeep M; Laport, Ginna G; Maloney, David G; Montoto, Silvia; Hari, Parameswaran N

    2014-02-01

    To examine the outcomes of patients with chemotherapy-sensitive mantle-cell lymphoma (MCL) following a first hematopoietic stem-cell transplantation (HCT), comparing outcomes with autologous (auto) versus reduced-intensity conditioning allogeneic (RIC allo) HCT and with transplantation applied at different times in the disease course. In all, 519 patients who received transplantations between 1996 and 2007 and were reported to the Center for International Blood and Marrow Transplant Research were analyzed. The early transplantation cohort was defined as those patients in first partial or complete remission with no more than two lines of chemotherapy. The late transplantation cohort was defined as all the remaining patients. Auto-HCT and RIC allo-HCT resulted in similar overall survival from transplantation for both the early (at 5 years: 61% auto-HCT v 62% RIC allo-HCT; P = .951) and late cohorts (at 5 years: 44% auto-HCT v 31% RIC allo-HCT; P = .202). In both early and late transplantation cohorts, progression/relapse was lower and nonrelapse mortality was higher in the allo-HCT group. Overall survival and progression-free survival were highest in patients who underwent auto-HCT in first complete response. Multivariate analysis of survival from diagnosis identified a survival benefit favoring early HCT for both auto-HCT and RIC allo-HCT. For patients with chemotherapy-sensitive MCL, the optimal timing for HCT is early in the disease course. Outcomes are particularly favorable for patients undergoing auto-HCT in first complete remission. For those unable to achieve complete remission after two lines of chemotherapy or those with relapsed disease, either auto-HCT or RIC allo-HCT may be effective, although the chance for long-term remission and survival is lower.

  4. Modal density of rectangular structures in a wide frequency range

    Science.gov (United States)

    Parrinello, A.; Ghiringhelli, G. L.

    2018-04-01

    A novel approach to investigate the modal density of a rectangular structure in a wide frequency range is presented. First, the modal density is derived, in the whole frequency range of interest, on the basis of sound transmission through the infinite counterpart of the structure; then, it is corrected by means of the low-frequency modal behavior of the structure, taking into account actual size and boundary conditions. A statistical analysis reveals the connection between the modal density of the structure and the transmission of sound through its thickness. A transfer matrix approach is used to compute the required acoustic parameters, making it possible to deal with structures having arbitrary stratifications of different layers. A finite element method is applied on coarse grids to derive the first few eigenfrequencies required to correct the modal density. Both the transfer matrix approach and the coarse grids involved in the finite element analysis grant high efficiency. Comparison with alternative formulations demonstrates the effectiveness of the proposed methodology.

  5. Approximation of the modal damping coefficients equivalent to material damping by harmonic excitation with ASKA

    International Nuclear Information System (INIS)

    Edme, R.

    1983-01-01

    If a dynamic response analysis (harmonic excitation) is carried out with the modal method, the modal damping coefficients must be approximated to match the structural damping. The program ASKA-Damping, which also supplies an error assessment of the approximation, was developed for this purpose. The modal method and the direct method are applied to a test example and their results compared. It is suggested that the ASKA manufacturers extend the spectral earthquake response analysis to take these modal damping coefficients into account so that the results become less conservative. (orig.) [de

  6. Uncertainty in particle number modal analysis during transient operation of compressed natural gas, diesel, and trap-equipped diesel transit buses.

    Science.gov (United States)

    Holmén, Britt A; Qu, Yingge

    2004-04-15

    monitor particle emissions with high-resolution real-time instruments and account for the operating regime of the vehicle using time-series analysis to develop predictive number emissions models.

  7. Direct restoration modalities of fractured central maxillary incisors: A multi-levels validated finite elements analysis with in vivo strain measurements.

    Science.gov (United States)

    Davide, Apicella; Raffaella, Aversa; Marco, Tatullo; Michele, Simeone; Syed, Jamaluddin; Massimo, Marrelli; Marco, Ferrari; Antonio, Apicella

    2015-12-01

    To quantify the influence of fracture geometry and restorative materials rigidity on the stress intensity and distribution of restored fractured central maxillary incisors (CMI) with particular investigation of the adhesive interfaces. Ancillary objectives are to present an innovative technology to measure the in vivo strain state of sound maxillary incisors and to present the collected data. A validation experimental biomechanics approach has been associated to finite element analysis. FEA models consisted of CMI, periodontal ligament and the corresponding alveolar bone process. Three models were created representing different orientation of the fracture planes. Three different angulations of the fracture plane in buccal-palatal direction were modeled: the fracture plane perpendicular to the long axis in the buccal-palatal direction (0°); the fracture plane inclined bucco-palatally in apical-coronal direction (-30°); the fracture plane inclined palatal-buccally in apical-coronal direction (+30°). First set of computing runs was performed for in vivo FE-model validation purposes. In the second part, a 50N force was applied on the buccal aspect of the CMI models. Ten patients were selected and subjected to the strain measurement of CMI under controlled loading conditions. The main differences were noticed in the middle and incisal thirds of incisors crowns, due to the presence of the incisal portion restoration. The stress intensity in -30° models is increased in the enamel structure close to the restoration, due to a thinning of the remaining natural tissues. The rigidity of the restoring material slightly reduces such phenomenon. -30° model exhibits the higher interfacial stress in the adhesive layer with respect to +30° and 0° models. The lower stress intensity was noticed in the 0° models, restoration material rigidity did not influenced the interfacial stress state in 0° models. On the contrary, material rigidity influenced the interfacial stress state

  8. What is the most accurate whole-body imaging modality for assessment of local and distant recurrent disease in colorectal cancer? A meta-analysis. Imaging for recurrent colorectal cancer

    International Nuclear Information System (INIS)

    Maas, Monique; Lambregts, Doenja M.J.; Rutten, Iris J.G.; Cappendijk, Vincent C.; Beets-Tan, Regina G.H.; Nelemans, Patty J.; Beets, Geerard L.

    2011-01-01

    The objective of this study was to compare the diagnostic performance of positron emission tomography (PET), PET/CT, CT and MRI as whole-body imaging modalities for the detection of local and/or distant recurrent disease in colorectal cancer (CRC) patients who have a (high) suspicion of recurrent disease, based on clinical findings or rise in carcinoembryonic antigen (CEA). A meta-analysis was undertaken. PubMed and Embase were searched for studies on the accuracy of whole-body imaging for patients with suspected local and/or distant recurrence of their CRC. Additionally, studies had to have included at least 20 patients with CRC and 2 x 2 contingency tables had to be provided or derivable. Articles evaluating only local recurrence or liver metastasis were excluded. Summary receiver-operating characteristic (ROC) curves were constructed from the data on sensitivity and specificity of individual studies and pooled estimates of diagnostic odds ratios (DORs) and areas under the ROC curve (AUCs) were calculated. To test for heterogeneity the Cochran Q test was used. Fourteen observational studies were included which evaluated PET, PET/CT, CT and/or MRI. Study results were available in 12 studies for PET, in 5 studies for CT, in 5 studies for PET/CT and in 1 study for MRI. AUCs for PET, PET/CT and CT were 0.94 (0.90-0.97), 0.94 (0.87-0.98) and 0.83 (0.72-0.90), respectively. In patient based analyses PET/CT had a higher diagnostic performance than PET with an AUC of 0.95 (0.89-0.97) for PET/CT vs 0.92 (0.86-0.96) for PET. Both whole-body PET and PET/CT are very accurate for the detection of local and/or distant recurrent disease in CRC patients with a (high) suspicion of recurrent disease. CT has the lowest diagnostic performance. This difference is probably mainly due to the lower accuracy of CT for detection of extrahepatic metastases (including local recurrence). For clinical practice PET/CT might be the modality of choice when evaluating patients with a (high

  9. Statistical test of reproducibility and operator variance in thin-section modal analysis of textures and phenocrysts in the Topopah Spring member, drill hole USW VH-2, Crater Flat, Nye County, Nevada

    International Nuclear Information System (INIS)

    Moore, L.M.; Byers, F.M. Jr.; Broxton, D.E.

    1989-06-01

    A thin-section operator-variance test was given to the 2 junior authors, petrographers, by the senior author, a statistician, using 16 thin sections cut from core plugs drilled by the US Geological Survey from drill hole USW VH-2 standard (HCQ) drill core. The thin sections are samples of Topopah Spring devitrified rhyolite tuff from four textural zones, in ascending order: (1) lower nonlithophysal, (2) lower lithopysal, (3) middle nonlithophysal, and (4) upper lithophysal. Drill hole USW-VH-2 is near the center of the Crater Flat, about 6 miles WSW of the Yucca Mountain in Exploration Block. The original thin-section labels were opaqued out with removable enamel and renumbered with alpha-numeric labels. The sliders were then given to the petrographer operators for quantitative thin-section modal (point-count) analysis of cryptocrystalline, spherulitic, granophyric, and void textures, as well as phenocryst minerals. Between operator variance was tested by giving the two petrographers the same slide, and within-operator variance was tested by the same operator the same slide to count in a second test set, administered at least three months after the first set. Both operators were unaware that they were receiving the same slide to recount. 14 figs., 6 tabs

  10. A Modal Description of Multiport Antennas

    Directory of Open Access Journals (Sweden)

    Jonathan J. Lynch

    2011-01-01

    Full Text Available This paper presents a modal description of multiport antennas that leads directly to a rigorous network representation and simple quadratic expressions for gain, efficiency, and effective area. The analysis shows that the transmitting and receiving properties of an element antenna array are exactly described by a 2×2 element scattering matrix together with a set of orthonormal mode functions and accounts for effects such as mutual coupling, scattering, reflection, and losses. The approach is quite general, only requiring that the antenna be finite and reciprocal. The scattering network description simplifies accounting of power flow while retaining a close connection to the physical antenna characteristics. The orthonormal mode functions provide a complete basis for radiated and received fields, facilitating beamforming. The theory provides rigorous definitions of input-output signals and links them to the underlying electromagnetics in a straightforward manner.

  11. Exploring prayer as a spiritual modality.

    Science.gov (United States)

    Farah, Jennifer; McColl, Mary Ann

    2008-02-01

    What does it mean to focus on the spiritual in occupational therapy? What interventions would qualify as spiritual modalities? This paper attempts to define the boundaries of what may be considered legitimate uses of spirituality in occupational therapy by using the example of prayer. The purpose of this paper was to provide an in-depth analysis of the use of prayer in practice. Medical and allied health journals were searched using the terms spirituality, spirit, religion, and prayer. Identified articles were synthesized to identify potential advantages and disadvantages of using prayer in therapy. Prayer can be considered an appropriate occupational therapy intervention so long as four questions can be answered positively. To answer these questions, guidelines are provided that will lead the therapist through a decision making process to determine the appropriateness of incorporating prayer into any clinical situation.

  12. Modal identification of composite structures using Eigen realization method

    International Nuclear Information System (INIS)

    Hamidzadeh, H.R.; Afolabi, D.

    1996-01-01

    Experimental modal analysis has proved to be a useful tool to determine the vibration response of complex composite structures. An accurate method for extracting modal parameters of these type of structures are presented. The method used experimental impulse response of the system as input and provides natural frequencies and damping ratios of a dynamic system. The employed theories are Eigen Realization and Impulse Response methods. The adopted method is superior to other available methods in time and frequency domains. The presented method is proven to provide robustness with respect to measured noise

  13. Most and Least Helpful Events in Three Supervision Modalities

    Science.gov (United States)

    Fickling, Melissa J.; Borders, L. DiAnne; Mobley, Keith A.; Wester, Kelly

    2017-01-01

    The authors conducted a content analysis of supervisors' (n = 10) and supervisees' (n = 31) descriptions (n = 707) of most and least helpful significant events in individual, group, and triadic supervision across 1 semester. Categories by group for each modality and areas of agreement and disagreement are highlighted.

  14. Mixing Categories and Modal Logics in the Quantum Setting

    NARCIS (Netherlands)

    Cinà, G.; Aerts, D.; de Ronde, C.; Freytes, H.; Giuntini, R.

    2016-01-01

    The study of the foundations of Quantum Mechanics, especially after the advent of Quantum Computation and Information, has benefited from the application of category-theoretic tools and modal logics to the analysis of Quantum processes: we witness a wealth of theoretical frameworks casted in either

  15. Modal characteristics and fatigue strength of compressor blades

    International Nuclear Information System (INIS)

    Kim, Kyung Kook; Lee, Young Shin

    2014-01-01

    High-cycle fatigue (HCF) has been identified as one of the primary causes of gas turbine engine failure. The modal characteristics and endurance strength of a 5 MW gas turbine engine blade developed by Doosan Heavy Industries and Construction Co., Ltd. in HCF fracture were verified through analysis and tests to determine the reliability of the compressor blade. A compressor blade design procedure that considers HCF life was performed in the following order: airfoil and blade profile design, modal analysis, stress distribution test, stress endurance limit test, and fatigue life verification. This study analyzed the Campbell diagram and estimated resonance risk on the basis of the natural frequency analysis and modal test of the compressor blade to guarantee safe and operational reliability. In addition, the maximum stress point of the compressor blade was determined through stress distribution analysis and test. The bonding point of the strain gage was determined by using fatigue test. Stress endurance limit test was performed based on the results of these tests. This research compared and verified the modal characteristics and endurance strengths of the compressor blades to prevent HCF fracture, which is among the major causes of gas turbine engine damage. A fatigue life design procedure of compressor blades was established. The 5 MW class gas turbine compressor blade is well designed in terms of resonance stability and fatigue endurance limit.

  16. Modal characteristics and fatigue strength of compressor blades

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Kook [Doosan Heavy Industries and Construction, Changwon (Korea, Republic of); Lee, Young Shin [Chungnam National University, Daejeon (Korea, Republic of)

    2014-04-15

    High-cycle fatigue (HCF) has been identified as one of the primary causes of gas turbine engine failure. The modal characteristics and endurance strength of a 5 MW gas turbine engine blade developed by Doosan Heavy Industries and Construction Co., Ltd. in HCF fracture were verified through analysis and tests to determine the reliability of the compressor blade. A compressor blade design procedure that considers HCF life was performed in the following order: airfoil and blade profile design, modal analysis, stress distribution test, stress endurance limit test, and fatigue life verification. This study analyzed the Campbell diagram and estimated resonance risk on the basis of the natural frequency analysis and modal test of the compressor blade to guarantee safe and operational reliability. In addition, the maximum stress point of the compressor blade was determined through stress distribution analysis and test. The bonding point of the strain gage was determined by using fatigue test. Stress endurance limit test was performed based on the results of these tests. This research compared and verified the modal characteristics and endurance strengths of the compressor blades to prevent HCF fracture, which is among the major causes of gas turbine engine damage. A fatigue life design procedure of compressor blades was established. The 5 MW class gas turbine compressor blade is well designed in terms of resonance stability and fatigue endurance limit.

  17. Calibrated Noncontact Exciters for Optical Modal Analysis

    Directory of Open Access Journals (Sweden)

    Henrik O. Saldner

    1996-01-01

    Full Text Available Two types of exciters were investigated experimentally One of the exciters uses a small permanent magnet fastened on the object. The force is introduced by the change in the electromagnetic field from a coil via an air gap. The second exciter is an eddy-current electromagnet one. The amplitude of the forces from these exciters are calibrated by using dynamic reciprocity in conjunction with electronic holography. These forces strongly depend upon the distance between the exciter and the object.

  18. Modal analysis for floors in lightweight buildings

    DEFF Research Database (Denmark)

    Sjökvist, Lars-Göran; Brunskog, Jonas

    2007-01-01

    of acoustical prediction methods for those houses. The calculation standard EN 12354 is under evaluation since it cannot include most of the wooden houses that are built. It is important during such a work to have a great understanding of the acoustical behaviour for the wooden houses. The floors in lightweight...... constructions usually consist of plates that are stiffened by beams and by the dividing walls. In this study the wave equation for a plate is expanded by Fourier series and an analytical solution in terms of the eigenmodes of the entire system is presented. The studied system consists of one lightweigt floor...

  19. Experienced Sensory Modalities in Dream Recall

    OpenAIRE

    岡田, 斉

    2000-01-01

    The purpose of the present study is to survey the frequency of visual, auditory, kinaesthetic, cutaneous, organic, gustatory, and olfactory experience in dream recall. A total of 1267 undergraduate students completed a dream recall frequency questionnaire, which contained a question about dream recall frequency and about recall frequency of seven sensory modalities. Results showed that seven sensory modalities were divided into two groups; normally perceived sensory modalities in dreaming, wh...

  20. Modal response of interior mass based upon external measurements

    International Nuclear Information System (INIS)

    Chow, C T; Eli, M; Jorgensen, B R; Woehrle, T.

    1999-01-01

    Modal response testing has been used to predict the motion of interior masses of a system in which only external instrumentation is allowed. Testing of this form may occasionally be necessary in validation of a computer model, but also has potential as a tool for validating individual assemblies in a QA process. Examination of the external frequency response and mode shapes can offer insight into interior response. The interpretation of these results is improved through parallel analytical solutions. A simple, three-mass model has been examined experimentally and analytically to demonstrate modal theory. These results show the limitations of the external measurement in predicting internal response due to transmissibility. A procedure for utilizing external testing is described. The question posed through this research is whether or not modal correlation analysis can be adapted for use in systems for which instrumentation of critical components is missing

  1. STRATEGIC AND ECONOMIC MODALITY OF ENVIRONMENTAL DIPLOMACY

    Directory of Open Access Journals (Sweden)

    А. Bokhan

    2018-01-01

    Full Text Available Modern development of humanity and its well-being is measured by the parameters of progressive achievements, global resonance and ecological warnings. XXI century, forming a new architecture of the world economy, which requires countries to resource diversification, market innovation and modification of the concept of leadership in combinatorial forms of competition and confrontation, consolidation and partnership. The dialogue of civilizations always contains contradictions and demonstrates the relative stability of communities in terms of ecological risk. International politicians are calling for the approval of constructivism economic activities on the basis of environmental diplomacy. Purpose. Determination of activation modality stratagem environmental diplomacy in the context of consolidating the areas of international economic relations, globalization challenges and opportunities. Result. New aspirations of humankind radically change the idea of naturalness and safety of its habitat, increase the importance of information and technological attributes of activity, cause the reactionary nature of the scale of the economic confrontation. Pause economic and technological expansionism unrealistic, but to channel the energy in a more environmental expansionism direction is necessary. Great hopes are placed on the active forms of diplomacy based on multi-level mobility of its subjects and ecological factors strengthen countries stratification. Traditionally, diplomacy is synchronized with the negotiation process, which are presented to the interests and intentions, tactics and strategy of the leaders of the political and business elite of the world. The development of environmental analysis diplomacy takes place under the pressure of massive information flows, multinational business interests and ideology of the hybrid wars. Environmental diplomacy is able to set the modality (way hypothetical implementation, realistic, pragmatic and forward

  2. Modalities of hemodialysis: Quality improvement

    Directory of Open Access Journals (Sweden)

    Ayman Karkar

    2012-01-01

    Full Text Available Hemodialysis (HD treatment had, over many years, improved the survival rate of patients with end-stage renal disease. However, standard or conventional HD prescription is far from being optimal in replacing the function of normal kidneys. Its unphysiologic clearance pattern and inability to remove all types and sizes of uremic toxins results in inter- and intra-dialysis complications and an unacceptably high rate of cardiovascular morbidity and mortality. Efficiency of HD can be improved by increasing blood and dialysate flow rates, dialyzer size and surface area and duration and frequency of dialysis sessions. Home HD, where short daily or long slow nocturnal HD sessions can conveniently be performed, provides an excellent option for quality of life improvement and reduction in morbidity and mortality. Recent innovations in the specifications of HD machines and improvement in dialysis membranes characteristics and water treatment technology paved the way for achieving quality HD. These advancements have resulted in efficient implementation of adsorption, diffusion and/or convection principles using adsorption HD, hemofiltration, hemodiafiltration (HDF and online HDF modalities in order to achieve optimum HD. Implementation of these innovations resulted in better quality care achievements in clinical practice and reduction in morbidity and mortality rates among HD patients.

  3. KINERJA KEUANGAN PADA USAHA KECIL MENENGAH PENERIMA DANA BERGULIR MODAL KERJA DI KABUPATEN KEDIRI

    Directory of Open Access Journals (Sweden)

    Jabal Tarik Ibrahim

    2017-03-01

    Full Text Available The objective of research is to analyze the financial performance of UKM beforeand after receiving Dana Bergulir Modal Kerja. The main data that is collected as secondarydata. Descriptive analysis is used to investigation on company characteristic has received DanaBergulir Modal Kerja, while the financial and marketing are analyzed by using quantitaveanalysis which used financial ratio analysis and different t-test. Result of analysis showed thatthe organized of Dana Bergulir Modal Kerja done by the businessmen who has right target.There’s only one financial ratio index that has real differenciates statistically that is net profitmargin showed that almost the big of UD decreased on that index. Statistically the sellingturnover after receiving Dana Bergulir Modal Kerja. The right empowerment for UKM by DanaBergulir Modal Kerja is done by “tanggung renteng”system.

  4. Cross-modal decoupling in temporal attention.

    Science.gov (United States)

    Mühlberg, Stefanie; Oriolo, Giovanni; Soto-Faraco, Salvador

    2014-06-01

    Prior studies have repeatedly reported behavioural benefits to events occurring at attended, compared to unattended, points in time. It has been suggested that, as for spatial orienting, temporal orienting of attention spreads across sensory modalities in a synergistic fashion. However, the consequences of cross-modal temporal orienting of attention remain poorly understood. One challenge is that the passage of time leads to an increase in event predictability throughout a trial, thus making it difficult to interpret possible effects (or lack thereof). Here we used a design that avoids complete temporal predictability to investigate whether attending to a sensory modality (vision or touch) at a point in time confers beneficial access to events in the other, non-attended, sensory modality (touch or vision, respectively). In contrast to previous studies and to what happens with spatial attention, we found that events in one (unattended) modality do not automatically benefit from happening at the time point when another modality is expected. Instead, it seems that attention can be deployed in time with relative independence for different sensory modalities. Based on these findings, we argue that temporal orienting of attention can be cross-modally decoupled in order to flexibly react according to the environmental demands, and that the efficiency of this selective decoupling unfolds in time. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  5. Three-valued logics in modal logic

    NARCIS (Netherlands)

    Kooi, Barteld; Tamminga, Allard

    2013-01-01

    Every truth-functional three-valued propositional logic can be conservatively translated into the modal logic S5. We prove this claim constructively in two steps. First, we define a Translation Manual that converts any propositional formula of any three-valued logic into a modal formula. Second, we

  6. Determination of HER2 and p53 Mutations by Sequence Analysis Method and EGFR/Chromosome 7 Gene Status by Fluorescence in Situ Hybridization for the Predilection of Targeted Therapy Modalities in Immunohistochemically Triple Negative Breast Carcinomas in Turkish Population.

    Science.gov (United States)

    Pala, Emel Ebru; Bayol, Umit; Keskin, Elif Usturali; Ozguzer, Alp; Kucuk, Ulku; Ozer, Ozge; Koc, Altug

    2015-09-01

    Triple negative breast cancer (TNBC), an agressive subtype accounts nearly 15 % of all breast carcinomas. Conventional chemotherapy is the only treatment modality thus new, effective targeted therapy methods have been investigated. Epidermal growth factor receptor (EGFR) inhibitors give hope according to the recent studies results. Also therapeutic agents have been tried against aberrant p53 signal activity as TNBC show high p53 mutation rates. Our aim was to detect the incidence of mutations/amplifications identified in TNBC in our population. Here we used sequence analysis to detect HER2 (exon 18-23), p53 (exon 5-8) mutations; fluorescence in situ hybridization (FISH) method to analyse EGFR/chromosome 7 centromere gene status in 82 immunohistochemically TNBC. Basaloid phenotype was identified in 49 (59.8 %) patients. EGFR amplification was noted in 5 cases (6.1 %). All EGFR amplified cases showed EGFR overexpression by immunohistochemistry (IHC). p53 mutations were identified in 33 (40.2 %) cases. Almost 60 % of the basal like breast cancer cases showed p53 mutation. Only one case showed HER2 mutation (exon 20:g.36830_3). Our results showed that gene amplification is not the unique mechanism in EGFR overexpression. IHC might be used in the decision of anti-EGFR therapy in routine practice. p53 mutation rate was lower than the rates reported in the literature probably due to ethnic differences and low sensitivity of sanger sequences in general mutation screening. We also established the rarity of HER2 mutation in TNBC. In conclusion EGFR and p53 are the major targets in TNBC also for our population.

  7. Odors bias time perception in visual and auditory modalities

    Directory of Open Access Journals (Sweden)

    Zhenzhu eYue

    2016-04-01

    Full Text Available Previous studies have shown that emotional states alter our perception of time. However, attention, which is modulated by a number of factors, such as emotional events, also influences time perception. To exclude potential attentional effects associated with emotional events, various types of odors (inducing different levels of emotional arousal were used to explore whether olfactory events modulated time perception differently in visual and auditory modalities. Participants were shown either a visual dot or heard a continuous tone for 1000 ms or 4000 ms while they were exposed to odors of jasmine, lavender, or garlic. Participants then reproduced the temporal durations of the preceding visual or auditory stimuli by pressing the spacebar twice. Their reproduced durations were compared to those in the control condition (without odor. The results showed that participants produced significantly longer time intervals in the lavender condition than in the jasmine or garlic conditions. The overall influence of odor on time perception was equivalent for both visual and auditory modalities. The analysis of the interaction effect showed that participants produced longer durations than the actual duration in the short interval condition, but they produced shorter durations in the long interval condition. The effect sizes were larger for the auditory modality than those for the visual modality. Moreover, by comparing performance across the initial and the final blocks of the experiment, we found odor adaptation effects were mainly manifested as longer reproductions for the short time interval later in the adaptation phase, and there was a larger effect size in the auditory modality. In summary, the present results indicate that odors imposed differential impacts on reproduced time durations, and they were constrained by different sensory modalities, valence of the emotional events, and target durations. Biases in time perception could be accounted for by a

  8. Odors Bias Time Perception in Visual and Auditory Modalities.

    Science.gov (United States)

    Yue, Zhenzhu; Gao, Tianyu; Chen, Lihan; Wu, Jiashuang

    2016-01-01

    Previous studies have shown that emotional states alter our perception of time. However, attention, which is modulated by a number of factors, such as emotional events, also influences time perception. To exclude potential attentional effects associated with emotional events, various types of odors (inducing different levels of emotional arousal) were used to explore whether olfactory events modulated time perception differently in visual and auditory modalities. Participants were shown either a visual dot or heard a continuous tone for 1000 or 4000 ms while they were exposed to odors of jasmine, lavender, or garlic. Participants then reproduced the temporal durations of the preceding visual or auditory stimuli by pressing the spacebar twice. Their reproduced durations were compared to those in the control condition (without odor). The results showed that participants produced significantly longer time intervals in the lavender condition than in the jasmine or garlic conditions. The overall influence of odor on time perception was equivalent for both visual and auditory modalities. The analysis of the interaction effect showed that participants produced longer durations than the actual duration in the short interval condition, but they produced shorter durations in the long interval condition. The effect sizes were larger for the auditory modality than those for the visual modality. Moreover, by comparing performance across the initial and the final blocks of the experiment, we found odor adaptation effects were mainly manifested as longer reproductions for the short time interval later in the adaptation phase, and there was a larger effect size in the auditory modality. In summary, the present results indicate that odors imposed differential impacts on reproduced time durations, and they were constrained by different sensory modalities, valence of the emotional events, and target durations. Biases in time perception could be accounted for by a framework of

  9. KEBIJAKAN DALAM PENENTUAN DAN PENDANAAN MODAL KERJA PERUSAHAAN

    Directory of Open Access Journals (Sweden)

    Miswanto Miswanto

    2012-10-01

    Full Text Available Abstract: Policy in Determining and Financing Company’s Working Capital. In funding working capital, a company can use hedging policy, conservative policy, and aggressive policy. In relation to long-term versus short-term financing, temporary versus permanent current assets, and the trade-off between risk and profitability, it can be concluded that when the temporary current assets are financed by short-term financing they have moderate risk and profitability, when the temporary current assets are financed by long-term financing they have low risk and profitability, when the permanent current assets are financed by short-term funding they have high risk and profitability, and when the permanent current assets are financed by long-term financing they have moderate risk-profitability. To measure the performance of the working capital management, the working capital position of the company needs to be analyzed. By using the data presented on the balance sheet and income statement, the company can carry out the analysis of working capital performance using financial ratio analysis on working capital, analysis of the funding sources and use of funding statement, and analysis of the company's cash flow statement. Keywords: liquidity, capital, financing, profitability, and risk   Abstrak: Kebijakan dalam Penentuan dan Pendanaan Modal Kerja Perusahaan. Dalam mendanai modal kerja, perusahaan dapat menggunakan kebijakan hedging, kebijakan konservatif, dan kebijakan agresif. Dalam hubungannya antara pendanaan jangka pendek versus jangka panjang, aktiva lancar temporer versus permanen, dan trade-off antara risiko dan profitabilitas diperoleh kesimpulan bahwa jika aktiva lancar temporer dibiayai dengan pendanaan jangka pendek memiliki risiko dan profitabilitas moderat, jika aktiva lancar temporer dibiayai dengan pendanaan jangka panjang memiliki risiko dan profitabilitas rendah, jika aktiva lancar permanen dibiayai dengan pendanaan jangka pendek memiliki

  10. Aeroelastic modal dynamics of wind turbines including anisotropic effects

    Energy Technology Data Exchange (ETDEWEB)

    Fisker Skjoldan, P.

    2011-03-15

    Several methods for aeroelastic modal analysis of a rotating wind turbine are developed and used to analyse the modal dynamics of two simplified models and a complex model in isotropic and anisotropic conditions. The Coleman transformation is used to enable extraction of the modal frequencies, damping, and periodic mode shapes of a rotating wind turbine by describing the rotor degrees of freedom in the inertial frame. This approach is valid only for an isotropic system. Anisotropic systems, e.g., with an unbalanced rotor or operating in wind shear, are treated with the general approaches of Floquet analysis or Hill's method which do not provide a unique reference frame for observing the modal frequency, to which any multiple of the rotor speed can be added. This indeterminacy is resolved by requiring that the periodic mode shape be as constant as possible in the inertial frame. The modal frequency is thus identified as the dominant frequency in the response of a pure excitation of the mode observed in the inertial frame. A modal analysis tool based directly on the complex aeroelastic wind turbine code BHawC is presented. It uses the Coleman approach in isotropic conditions and the computationally efficient implicit Floquet analysis in anisotropic conditions. The tool is validated against system identifications with the partial Floquet method on the nonlinear BHawC model of a 2.3 MW wind turbine. System identification results show that nonlinear effects on the 2.3 MW turbine in most cases are small, but indicate that the controller creates nonlinear damping. In isotropic conditions the periodic mode shape contains up to three harmonic components, but in anisotropic conditions it can contain an infinite number of harmonic components with frequencies that are multiples of the rotor speed. These harmonics appear in calculated frequency responses of the turbine. Extreme wind shear changes the modal damping when the flow is separated due to an interaction between

  11. Don Cossack Army Charters of the Mid 18th Century Via the Category of Modality

    Directory of Open Access Journals (Sweden)

    Elena Mihaylovna Sheptukhina

    2015-12-01

    Full Text Available The article deals with the language means of modality in the texts of military charters of the mid 18th cent. from the "Mikhailovsky stanitza hetman" archive (State Achieve of Volgograd Region. Military charters used to be major documents of legislation within Don Cossack Host, as being at that time an administrative unit in the territory of Russian Empire. The results of the contextual analysis verify the following facts: the charter texts are mainly characterized by an imperative tone of regulation that is caused by coordination between dominant meanings of a propositional (situational modality of necessity and pragmatic modality of volition, that are thought to be interrelated in utterances. The modal meaning of necessity is marked by the verbal construction with an independent infinitive or the combinations of modal verbs (imet' / possess; nadlezhat' / be to, modal predicatives with a dependent infinitive (dolzhen, nadobno, etc. / must (have to. Modality of volition is presented with a set of lexical units that possess the meanings of ordering, permission, offers, verbal forms that are used as performatives, or point to the status of a subject, etc. The texts under study represent some other modal meanings: possibility (with the words moch' / be able to; mozhno / could / may combined with an infinitive, in subordinate clauses with a particle li (if / wether, etc. in an interrogative clauses. In complex sentences with subordination combinations of various modal meanings are observed.

  12. Extending Modal Transition Systems with Structured Labels

    DEFF Research Database (Denmark)

    Bauer, Sebastian S.; Juhl, Line; Larsen, Kim Guldstrand

    2012-01-01

    We introduce a novel formalism of label-structured modal transition systems that combines the classical may/must modalities on transitions with structured labels that represent quantitative aspects of the model. On the one hand, the specification formalism is general enough to include models like...... weighted modal transition systems and allows the system developers to employ more complex label refinement than in the previously studied theories. On the other hand, the formalism maintains the desirable properties required by any specification theory supporting compositional reasoning. In particular, we...

  13. Verification of experimental modal modeling using HDR (Heissdampfreaktor) dynamic test data

    International Nuclear Information System (INIS)

    Srinivasan, M.G.; Kot, C.A.; Hsieh, B.J.

    1983-01-01

    Experimental modal modeling involves the determination of the modal parameters of the model of a structure from recorded input-output data from dynamic tests. Though commercial modal analysis algorithms are being widely used in many industries their ability to identify a set of reliable modal parameters of an as-built nuclear power plant structure has not been systematically verified. This paper describes the effort to verify MODAL-PLUS, a widely used modal analysis code, using recorded data from the dynamic tests performed on the reactor building of the Heissdampfreaktor, situated near Frankfurt, Federal Republic of Germany. In the series of dynamic tests on HDR in 1979, the reactor building was subjected to forced vibrations from different types and levels of dynamic excitations. Two sets of HDR containment building input-output data were chosen for MODAL-PLUS analyses. To reduce the influence of nonlinear behavior on the results, these sets were chosen so that the levels of excitation are relatively low and about the same in the two sets. The attempted verification was only partially successful in that only one modal model, with a limited range of validity, could be synthesized and in that the goodness of fit could be verified only in this limited range

  14. Cross-modal versus within-modal recall: differences in behavioral and brain responses.

    Science.gov (United States)

    Butler, Andrew J; James, Karin H

    2011-10-31

    Although human experience is multisensory in nature, previous research has focused predominantly on memory for unisensory as opposed to multisensory information. In this work, we sought to investigate behavioral and neural differences between the cued recall of cross-modal audiovisual associations versus within-modal visual or auditory associations. Participants were presented with cue-target associations comprised of pairs of nonsense objects, pairs of nonsense sounds, objects paired with sounds, and sounds paired with objects. Subsequently, they were required to recall the modality of the target given the cue while behavioral accuracy, reaction time, and blood oxygenation level dependent (BOLD) activation were measured. Successful within-modal recall was associated with modality-specific reactivation in primary perceptual regions, and was more accurate than cross-modal retrieval. When auditory targets were correctly or incorrectly recalled using a cross-modal visual cue, there was re-activation in auditory association cortex, and recall of information from cross-modal associations activated the hippocampus to a greater degree than within-modal associations. Findings support theories that propose an overlap between regions active during perception and memory, and show that behavioral and neural differences exist between within- and cross-modal associations. Overall the current study highlights the importance of the role of multisensory information in memory. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. The modality effect and echoic persistence.

    Science.gov (United States)

    Watkins, O C; Watkins, M J

    1980-09-01

    The modality effect refers to the higher level of recall of the last few items of a list when presentation is auditory as opposed to visual. It is usually attributed to echoic memory. The effect may be sharply reduced by an ostensibly irrelevant auditory item appended to the end of the list. Previous research suggests that this "suffix effect" arises only when the suffix item occurs within 2 sec of the last list item. This finding strengthens the widely held assumption that echoic information decays within 2 sec, and has led to the assumption that if echoic information is to be useful in serial recall it must first be encoded into a more durable modality-independent form. Both assumptions conflict with the research reported here. The first two experiments demonstrate substantial suffix effects with suffix delays of 2 and 4 sec, indicating that echoic information lasts at least 4 sec. This finding implies that echoic information may aid recall directly, an implication that was supported in Experiments 3 and 4. In Experiment 3 serial recall was interrupted with a brief distractor task. The modality effect was smaller when this task was auditory than when it was visual, suggesting that echoic information was still available immediately prior to recency recall. In Experiment 4 list presentation was broken by a 4-sec pause; the modalities of the list halves were combined factorially. Interest focused on the recency positions of the first half. A modality effect was found at these positions when the second half was visual but not when it was auditory. This is contrary to the hypothesis that echoic information is encoded before recall, but is consistent with the hypothesis that echoic information is encoded before recall, but is consistent with the alternative hypothesis that echoic information is used directly at recall. The final two experiments concern the modality effect found when a delay is interpolated between list presentation and recall. Experiment 5 showed that

  16. DICOM versus HL7 for modality interfacing

    OpenAIRE

    Oosterwijk, Herman

    1998-01-01

    Digital modalities such as CT, MRI, Ultrasound and Computerized Radiography systems, generating softcopy images to be used by a Picture Archiving and Communication System (PACS), need to identify the images properly in order to retrieve and manage them. In many cases, a technologist re-enters patient demographic and study related information at the modality, even although it is usually already present somewhere in the hospital Information System (IS). In order to achieve a higher level of eff...

  17. Models of galaxies - The modal approach

    International Nuclear Information System (INIS)

    Lin, C.C.; Lowe, S.A.

    1990-01-01

    The general viability of the modal approach to the spiral structure in normal spirals and the barlike structure in certain barred spirals is discussed. The usefulness of the modal approach in the construction of models of such galaxies is examined, emphasizing the adoption of a model appropriate to observational data for both the spiral structure of a galaxy and its basic mass distribution. 44 refs

  18. A Comparison of Passion and Teaching Modality

    Directory of Open Access Journals (Sweden)

    Scott Greenberger

    2016-01-01

    Full Text Available Research exists that applies the dualistic model of passion to face-to-face teaching, but no research has applied this model to online instruction. Distance education theories imply a need to discover factors contributing to online faculty motivation to engage students. Although there has been extensive exploration of intrinsic and extrinsic motivation to teach online, factors contributing to consistent and optimal teaching behavior has received less attention. There is evidence that the passion construct is independent of both intrinsic and extrinsic motivation. A stratified random sample of online and face-to-face faculty (n = 92 were surveyed using the Passion Scale. The results showed that 95 percent of the sampled online faculty self-identified as passionate for their online instruction. In the between-groups analysis, there were no significant differences in the variables of passion orientation, harmonious passion, and obsessive passion by modality. This research provides a basis for future research of passion in online instruction. In addition, this study adds another dimension for research within distance education theory, providing increased evidence for what motivates online instructors to consistently and effectively engage students.

  19. Eigenvectors phase correction in inverse modal problem

    Science.gov (United States)

    Qiao, Guandong; Rahmatalla, Salam

    2017-12-01

    The solution of the inverse modal problem for the spatial parameters of mechanical and structural systems is heavily dependent on the quality of the modal parameters obtained from the experiments. While experimental and environmental noises will always exist during modal testing, the resulting modal parameters are expected to be corrupted with different levels of noise. A novel methodology is presented in this work to mitigate the errors in the eigenvectors when solving the inverse modal problem for the spatial parameters. The phases of the eigenvector component were utilized as design variables within an optimization problem that minimizes the difference between the calculated and experimental transfer functions. The equation of motion in terms of the modal and spatial parameters was used as a constraint in the optimization problem. Constraints that reserve the positive and semi-positive definiteness and the inter-connectivity of the spatial matrices were implemented using semi-definite programming. Numerical examples utilizing noisy eigenvectors with augmented Gaussian white noise of 1%, 5%, and 10% were used to demonstrate the efficacy of the proposed method. The results showed that the proposed method is superior when compared with a known method in the literature.

  20. FAKTOR PENENTU STRUKTUR MODAL: STUDI EMPIRIK PADA PERUSAHAAN MULTIFINANSIAL

    Directory of Open Access Journals (Sweden)

    Siti Ridloah

    2010-09-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui pengaruh variabel struktur aktiva, ukuran perusahaan, operating leverage, profitabilitas, likuiditas dan pertumbuhan penjualan terhadap Struktur Modal perusahaan sektor keuangan serta mengetahui variabel manakah yang paling berpengaruh terhadap stuktur modal. Populasi dalam penelitian ini adalah semua perusahaan sektor keuangan multifinansial yang terdaftar di BEI yang memiliki laporan keuangan dalam ICMD tahun 2008. Penentuan sampel penelitian ini menggunakan metode purposive sampling. Hasil analisis regresi menunjukkan bahwa ada pengaruh secara simultan variabel independen terhadap Struktur Modal. Hanya ada tiga variabel independen yang berpengaruh signifikan secara parsial terhadap variabel dependen yaitu ukuran perusahaan, profitabilitas dan likuiditas. Dari variabel-variabel tersebut, variabel yang paling berpengaruh terhadap stuktur modal adalah ukuran perusahaan. Saran yang penulis sampaikan dalam penelitian ini, bahwa untuk mencapai Struktur Modal yang optimal, perusahaan perlu meningkatkan profitabilitas, likuiditas dan ukuran perusahaan dengan cara meningkatkan profit margin dan meningkatkan asset yang dimiliki perusahaan. This study aims to determine the effect of asset structure variables, firm Size, operating leverage, profitability, liquidity and growth in sales of corporate capital structure of the financial sector as well as knowing which variables most affect the capital structure. The populations of this study were all multifinansial financial sector companies have been listed on the Stock Exchange which has ICMD financial statements in 2008. Purposive sampling method is used to analyse the samples of this study. The results of multiple regression analysis showed that there is a simultaneous effect of independent variables of corporate capital structure of the financial sector. There are only three independent variables that significantly influence the dependent variable that is

  1. Air versus terrestrial transport modalities: An energy and environmental comparison

    International Nuclear Information System (INIS)

    Federici, M.; Ulgiati, S.; Basosi, R.

    2009-01-01

    In the last 15 years, worldwide air transportation has grown at an average yearly rate of 4.5%. Forecasts confirm that this could be the average increase rate for the next 20 years, although recent oscillation of oil price translated into a slowing down of such a trend, with several air companies forced out of business. Within this framework, low cost airlines keep increasing their market share, in so making airplane to compete with terrestrial transport modalities, not only for medium and long distance, but also for short trips. This is because air transport is obviously faster than transport by trains and cars, and most often it also is a cheaper option in money terms. In spite of its apparent success, air transportation is a source of concern for many analysts, because it is considered as the more energy intensive and polluting transport modality. In order to explore the correctness of such an issue, we compared air transportation to high speed trains and other modern terrestrial modalities, by using a 'whole-system' approach. The present study applies an LCA-like approach, by taking into account all the energy and materials directly and indirectly required to make and operate infrastructures (i.e. tunnels, railways, highways) and vehicles. Efficiency and environmental loading are assessed by means of Material Flow Accounting, Embodied Energy Analysis and Emergy Synthesis methods. Results point out that the gap among the environmental performances of air, road and railway modalities is significantly narrower than expected. The thermodynamic and environmental costs of road and railway infrastructure cannot be disregarded as negligible. In a selected number of cases these transport modalities perform even worse than the air transportation mode, where infrastructures play a much smaller role.

  2. Air versus terrestrial transport modalities: An energy and environmental comparison

    Energy Technology Data Exchange (ETDEWEB)

    Federici, M.; Basosi, R. [Department of Chemistry and Center for Complex Systems Investigation, University of Siena, via Alcide De Gasperi 2, 53100 Siena (Italy); Ulgiati, S. [Department of Sciences for the Environment, ' ' Parthenope' ' University of Napoli, Centro Direzionale, Isola C4, I-80143 Napoli (Italy)

    2009-10-15

    In the last 15 years, worldwide air transportation has grown at an average yearly rate of 4.5%. Forecasts confirm that this could be the average increase rate for the next 20 years, although recent oscillation of oil price translated into a slowing down of such a trend, with several air companies forced out of business. Within this framework, low cost airlines keep increasing their market share, in so making airplane to compete with terrestrial transport modalities, not only for medium and long distance, but also for short trips. This is because air transport is obviously faster than transport by trains and cars, and most often it also is a cheaper option in money terms. In spite of its apparent success, air transportation is a source of concern for many analysts, because it is considered as the more energy intensive and polluting transport modality. In order to explore the correctness of such an issue, we compared air transportation to high speed trains and other modern terrestrial modalities, by using a ''whole-system'' approach. The present study applies an LCA-like approach, by taking into account all the energy and materials directly and indirectly required to make and operate infrastructures (i.e. tunnels, railways, highways) and vehicles. Efficiency and environmental loading are assessed by means of Material Flow Accounting, Embodied Energy Analysis and Emergy Synthesis methods. Results point out that the gap among the environmental performances of air, road and railway modalities is significantly narrower than expected. The thermodynamic and environmental costs of road and railway infrastructure cannot be disregarded as negligible. In a selected number of cases these transport modalities perform even worse than the air transportation mode, where infrastructures play a much smaller role. (author)

  3. A multi-modal approach to soft systems methodology

    OpenAIRE

    Bergvall-Kåreborn, Birgitta

    2002-01-01

    The main aim of my research is to explore ways of enriching Soft Systems Methodology by developing intellectual tools that can help designers to conceptualise, create and evaluate different design alternatives. This directs the focus on the methodology’s modelling phase even though some ideas related to analysis also will be presented. In order to realize this objective the study proposes the following supplements. Firstly, a framework of 15 modalities (knowledge areas) is suggested as a supp...

  4. Multi-modal Biomarkers to Discriminate Cognitive State

    Science.gov (United States)

    2015-11-01

    of timing and coordination in vocal and facial expression . 5.1 Audio-video AVEC depression database The 2014 Audio/Video Emotion Challenge (AVEC...signs of emotional experience. Journal of personality and social psychology. 39, 6 (1980), 1125. 37. Gaebel, W. and Wölwer, W. 1992. Facial expression ...Example modalities used in detection of these conditions include voice, facial expression , physiology, eye tracking, gait, and EEG analysis. Toward the

  5. Experimental modal identification of an existent earthen residential building

    OpenAIRE

    Aguilar, Rafael; Ramos, Luís F.; Torrealva, D.; Chácara, C.

    2013-01-01

    The paper presents the preliminary round of in-situ experimental tests carried out at “Hotel Comercio”, a historical construction located at the historical centre of Lima (capital of Peru). The building is a three story republican-type construction built at 19th Century with composite structure of Adobe and “Quincha”. The experimental works consisted on Operational Modal Analysis (OMA) tests aiming at identifying the dynamic characteristics of the building using the environmental noise as sou...

  6. An Introduction to Operational Modal Identification of Offshore Wind Turbine Structures

    DEFF Research Database (Denmark)

    Damgaard, Mads

    excitation originating from the rotating rotor and broadband excitation from air turbulence is present, which sets limitations on the applicability of operational modal analysis to wind turbine structures. The technical memorandum contains an introduction to the theory within experimental modal analysis and......The present technical memorandum “An Introduction to Operational Modal Identification of Offshore Wind Turbine Structures” is prepared in connection with an ongoing Ph.D study at Aalborg University. The memorandum is intended for use in the civil engineering field and may serve as an inspiration...

  7. Analysis of second order harmonic distortion due to transmitter non-linearity and chromatic and modal dispersion of optical OFDM SSB modulated signals in SMF-MMF fiber links

    Science.gov (United States)

    Patel, Dhananjay; Singh, Vinay Kumar; Dalal, U. D.

    2017-01-01

    Single mode fibers (SMF) are typically used in Wide Area Networks (WAN), Metropolitan Area Networks (MAN) and also find applications in Radio over Fiber (RoF) architectures supporting data transmission in Fiber to the Home (FTTH), Remote Antenna Units (RAUs), in-building networks etc. Multi-mode fibers (MMFs) with low cost, ease of installation and low maintenance are predominantly (85-90%) deployed in-building networks providing data access in local area networks (LANs). The transmission of millimeter wave signals through the SMF in WAN and MAN, along with the reuse of MMF in-building networks will not levy fiber reinstallation cost. The transmission of the millimeter waves experiences signal impairments due to the transmitter non-linearity and modal dispersion of the MMF. The MMF exhibiting large modal dispersion limits the bandwidth-length product of the fiber. The second and higher-order harmonics present in the optical signal fall within the system bandwidth. This causes degradation in the received signal and an unwanted radiation of power at the RAU. The power of these harmonics is proportional to the non-linearity of the transmitter and the modal dispersion of the MMF and should be maintained below the standard values as per the international norms. In this paper, a mathematical model is developed for Second-order Harmonic Distortion (HD2) generated due to non-linearity of the transmitter and chromatic-modal dispersion of the SMF-MMF optic link. This is also verified using a software simulation. The model consists of a Mach Zehnder Modulator (MZM) that generates two m-QAM OFDM Single Sideband (SSB) signals based on phase shift of the hybrid coupler (90° and 120°). Our results show that the SSB signal with 120° hybrid coupler has suppresses the higher-order harmonics and makes the system more robust against the HD2 in the SMF-MMF optic link.

  8. A robust methodology for modal parameters estimation applied to SHM

    Science.gov (United States)

    Cardoso, Rharã; Cury, Alexandre; Barbosa, Flávio

    2017-10-01

    The subject of structural health monitoring is drawing more and more attention over the last years. Many vibration-based techniques aiming at detecting small structural changes or even damage have been developed or enhanced through successive researches. Lately, several studies have focused on the use of raw dynamic data to assess information about structural condition. Despite this trend and much skepticism, many methods still rely on the use of modal parameters as fundamental data for damage detection. Therefore, it is of utmost importance that modal identification procedures are performed with a sufficient level of precision and automation. To fulfill these requirements, this paper presents a novel automated time-domain methodology to identify modal parameters based on a two-step clustering analysis. The first step consists in clustering modes estimates from parametric models of different orders, usually presented in stabilization diagrams. In an automated manner, the first clustering analysis indicates which estimates correspond to physical modes. To circumvent the detection of spurious modes or the loss of physical ones, a second clustering step is then performed. The second step consists in the data mining of information gathered from the first step. To attest the robustness and efficiency of the proposed methodology, numerically generated signals as well as experimental data obtained from a simply supported beam tested in laboratory and from a railway bridge are utilized. The results appeared to be more robust and accurate comparing to those obtained from methods based on one-step clustering analysis.

  9. Mixed-Modality Stimulation to Evoke Two Modalities Simultaneously in One Channel for Electrocutaneous Sensory Feedback.

    Science.gov (United States)

    Choi, Kyunghwan; Kim, Pyungkang; Kim, Kyung-Soo; Kim, Soohyun

    2017-12-01

    One of the long-standing challenges in upper limb prosthetics is restoring the sensory feedback that is missing due to amputation. Two approaches have previously been presented to provide various types of sensory information to users, namely, multi-modality sensory feedback and using an array of single-modality stimulators. However, the feedback systems used in these approaches were too bulky to be embedded in prosthesis sockets. In this paper, we propose an electrocutaneous sensory feedback method that is capable of conveying two modalities simultaneously with only one electrode. The stimulation method, which we call mixed-modality stimulation, utilizes the phenomenon in which the superposition of two electric pulse trains of different frequencies is able to evoke two different modalities (i.e., pressure and tapping) at the same time. We conducted psychophysical experiments in which healthy subjects were required to recognize the intensity of pressure or the frequency of tapping from mixed-modality or two-channel stimulations. The results demonstrated that the subjects were able to discriminate the features of the two modalities in one electrode during mixed-modality stimulation and that the accuracies of successful recognitions (mean ± standard deviation) for the two feedback variables were 84.3 ± 7% for mixed-modality stimulation and 89.5 ± 6% for two-channel dual-modality stimulation, showing no statistically significant difference. Therefore, mixed-modality stimulation is an attractive method for modulating two modalities independently with only one electrode, and it could be used for implementing a compact sensory feedback system that is able to provide two different types of sensory information from prosthetics.

  10. Metaphysical Modality, Modality of Predicate and the Theory of "Decisive Necessity”

    Directory of Open Access Journals (Sweden)

    L. Nabavi

    2010-01-01

    Full Text Available Aristotle in the Organon (1949: 9,30 a ,15-19 explicitly states that in a categorical syllogism when the minor premise is absolute (without modality operator and the major is necessary, the conclusion will be necessary too. This Aristotle's view has been the source of many conflicts and disputes in the history of logic. The famous logicians and historians of logic in the twentieth century as "Nicholas Rescher" and "Becker" believe that Aristotle's view is justifiable and defensible (at least compared to the first figure only if, the modality of major premise is considered as the property of predicate (modality de re. Today, we know very well that the modality of predicate is closely linked to Metaphysical and philosophical Modality. “Shihab al-Din al- Suhrawardi” in the theory of "Decisive (Battateh Necessity” by accepting this base, explicitly states that, in the beginning, the modality must be mentioned as a part of the predicate and then the modality of relation or copula is summarized and reduced to necessity. The modern formalization of the most important part of this theory is as follows: ("x (àAx É à Bx º ("x □ (àAx É à BxThis paper discusses the historical overview of the metaphysical modality firstly and then shows that the theory of "Decisive Necessity” is true and justified in a model of modal logic with equivalent accessibility relation and homogeneous possible world view (fixed domain.

  11. Modality-specific effects on crosstalk in task switching: evidence from modality compatibility using bimodal stimulation.

    Science.gov (United States)

    Stephan, Denise Nadine; Koch, Iring

    2016-11-01

    The present study was aimed at examining modality-specific influences in task switching. To this end, participants switched either between modality compatible tasks (auditory-vocal and visual-manual) or incompatible spatial discrimination tasks (auditory-manual and visual-vocal). In addition, auditory and visual stimuli were presented simultaneously (i.e., bimodally) in each trial, so that selective attention was required to process the task-relevant stimulus. The inclusion of bimodal stimuli enabled us to assess congruence effects as a converging measure of increased between-task interference. The tasks followed a pre-instructed sequence of double alternations (AABB), so that no explicit task cues were required. The results show that switching between two modality incompatible tasks increases both switch costs and congruence effects compared to switching between two modality compatible tasks. The finding of increased congruence effects in modality incompatible tasks supports our explanation in terms of ideomotor "backward" linkages between anticipated response effects and the stimuli that called for this response in the first place. According to this generalized ideomotor idea, the modality match between response effects and stimuli would prime selection of a response in the compatible modality. This priming would cause increased difficulties to ignore the competing stimulus and hence increases the congruence effect. Moreover, performance would be hindered when switching between modality incompatible tasks and facilitated when switching between modality compatible tasks.

  12. Mechanics of inter-modal tunneling in nonlinear waveguides

    Science.gov (United States)

    Jiao, Weijian; Gonella, Stefano

    2018-02-01

    In this article, we investigate the mechanics of nonlinearly induced inter-modal energy tunneling between flexurally-dominated and axially-dominated modes in phononic waveguides. Special attention is devoted to elucidating the role played by the coupling between axial and flexural degrees of freedom in the determination of the available mode hopping conditions and the associated mechanisms of deformation. Waveguides offer an ideal test bed to investigate the mechanics of nonlinear energy tunneling, due to the fact that they naturally feature, even at low frequencies, families of modes (flexural and axial) that are intrinsically characterized by extreme complementarity. Moreover, thanks to their geometric simplicity, their behavior can be explained by resorting to intuitive structural mechanics models that effectively capture the dichotomy and interplay between flexural and axial mechanisms. After having delineated the fundamental mechanics of flexural-to-axial hopping using the benchmark example of a homogeneous structure, we adapt the analysis to the case of periodic waveguides, in which the complex dispersive behavior due to periodicity results in additional richness of mode hopping mechanisms. We finally extend the analysis to periodic waveguides with internal resonators, in which the availability of locally-resonant bandgaps implies the possibility to activate the resonators even at relatively low frequencies, thus increasing the degree of modal complementarity that is available in the acoustic range. In this context, inter-modal tunneling provides an unprecedented mechanism to transfer conspicuous packets of energy to the resonating microstructure.

  13. Modal bifurcation in a high-Tc superconducting levitation system

    International Nuclear Information System (INIS)

    Taguchi, D; Fujiwara, S; Sugiura, T

    2011-01-01

    This paper deals with modal bifurcation of a multi-degree-of-freedom high-T c superconducting levitation system. As modeling of large-scale high-T c superconducting levitation applications, where plural superconducting bulks are often used, it can be helpful to consider a system constituting of multiple oscillators magnetically coupled with each other. This paper investigates nonlinear dynamics of two permanent magnets levitated above high-T c superconducting bulks and placed between two fixed permanent magnets without contact. First, the nonlinear equations of motion of the levitated magnets were derived. Then the method of averaging was applied to them. It can be found from the obtained solutions that this nonlinear two degree-of-freedom system can have two asymmetric modes, in addition to a symmetric mode and an antisymmetric mode both of which also exist in the linearized system. One of the backbone curves in the frequency response shows a modal bifurcation where the two stable asymmetric modes mentioned above appear with destabilization of the antisymmetric mode, thus leading to modal localization. These analytical predictions have been confirmed in our numerical analysis and experiments of free vibration and forced vibration. These results, never predicted by linear analysis, can be important for application of high-T c superconducting levitation systems.

  14. Different patterns of modality dominance across development.

    Science.gov (United States)

    Barnhart, Wesley R; Rivera, Samuel; Robinson, Christopher W

    2018-01-01

    The present study sought to better understand how children, young adults, and older adults attend and respond to multisensory information. In Experiment 1, young adults were presented with two spoken words, two pictures, or two word-picture pairings and they had to determine if the two stimuli/pairings were exactly the same or different. Pairing the words and pictures together slowed down visual but not auditory response times and delayed the latency of first fixations, both of which are consistent with a proposed mechanism underlying auditory dominance. Experiment 2 examined the development of modality dominance in children, young adults, and older adults. Cross-modal presentation attenuated visual accuracy and slowed down visual response times in children, whereas older adults showed the opposite pattern, with cross-modal presentation attenuating auditory accuracy and slowing down auditory response times. Cross-modal presentation also delayed first fixations in children and young adults. Mechanisms underlying modality dominance and multisensory processing are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Multilayer modal actuator-based piezoelectric transformers.

    Science.gov (United States)

    Huang, Yao-Tien; Wu, Wen-Jong; Wang, Yen-Chieh; Lee, Chih-Kung

    2007-02-01

    An innovative, multilayer piezoelectric transformer equipped with a full modal filtering input electrode is reported herein. This modal-shaped electrode, based on the orthogonal property of structural vibration modes, is characterized by full modal filtering to ensure that only the desired vibration mode is excited during operation. The newly developed piezoelectric transformer is comprised of three layers: a multilayered input layer, an insulation layer, and a single output layer. The electrode shape of the input layer is derived from its structural vibration modal shape, which takes advantage of the orthogonal property of the vibration modes to achieve a full modal filtering effect. The insulation layer possesses two functions: first, to couple the mechanical vibration energy between the input and output, and second, to provide electrical insulation between the two layers. To meet the two functions, a low temperature, co-fired ceramic (LTCC) was used to provide the high mechanical rigidity and high electrical insulation. It can be shown that this newly developed piezoelectric transformer has the advantage of possessing a more efficient energy transfer and a wider optimal working frequency range when compared to traditional piezoelectric transformers. A multilayer piezoelectric, transformer-based inverter applicable for use in LCD monitors or portable displays is presented as well.

  16. The metaphysics of quantum mechanics: Modal interpretations

    Science.gov (United States)

    Gluck, Stuart Murray

    2004-11-01

    This dissertation begins with the argument that a preferred way of doing metaphysics is through philosophy of physics. An understanding of quantum physics is vital to answering questions such as: What counts as an individual object in physical ontology? Is the universe fundamentally indeterministic? Are indiscernibles identical? This study explores how the various modal interpretations of quantum mechanics answer these sorts of questions; modal accounts are one of the two classes of interpretations along with so-called collapse accounts. This study suggests a new alternative within the class of modal views that yields a more plausible ontology, one in which the Principle of the Identity of Indisceribles is necessarily true. Next, it shows that modal interpretations can consistently deny that the universe must be fundamentally indeterministic so long as they accept certain other metaphysical commitments: either a perfect initial distribution of states in the universe or some form of primitive dispositional properties. Finally, the study sketches out a future research project for modal interpretations based on developing quantified quantum logic.

  17. Modal method for crack identification applied to reactor recirculation pump

    International Nuclear Information System (INIS)

    Miller, W.H.; Brook, R.

    1991-01-01

    Nuclear reactors have been operating and producing useful electricity for many years. Within the last few years, several plants have found cracks in the reactor coolant pump shaft near the thermal barrier. The modal method and results described herein show the analytical results of using a Modal Analysis test method to determine the presence, size, and location of a shaft crack. The authors have previously demonstrated that the test method can analytically and experimentally identify shaft cracks as small as five percent (5%) of the shaft diameter. Due to small differences in material property distribution, the attempt to identify cracks smaller than 3% of the shaft diameter has been shown to be impractical. The rotor dynamics model includes a detailed motor rotor, external weights and inertias, and realistic total support stiffness. Results of the rotor dynamics model have been verified through a comparison with on-site vibration test data

  18. Naturalizing aesthetics: brain areas for aesthetic appraisal across sensory modalities.

    Science.gov (United States)

    Brown, Steven; Gao, Xiaoqing; Tisdelle, Loren; Eickhoff, Simon B; Liotti, Mario

    2011-09-01

    We present here the most comprehensive analysis to date of neuroaesthetic processing by reporting the results of voxel-based meta-analyses of 93 neuroimaging studies of positive-valence aesthetic appraisal across four sensory modalities. The results demonstrate that the most concordant area of activation across all four modalities is the right anterior insula, an area typically associated with visceral perception, especially of negative valence (disgust, pain, etc.). We argue that aesthetic processing is, at its core, the appraisal of the valence of perceived objects. This appraisal is in no way limited to artworks but is instead applicable to all types of perceived objects. Therefore, one way to naturalize aesthetics is to argue that such a system evolved first for the appraisal of objects of survival advantage, such as food sources, and was later co-opted in humans for the experience of artworks for the satisfaction of social needs. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. A new algebraic white-noise modal combination rule - GAC(A)

    International Nuclear Information System (INIS)

    Mertens, P.G.

    1994-01-01

    It is a well known fact that above the rigid frequency the maximum dynamic modal responses even with different multiple supports can be combined algebraically. Below the rigid frequency, and more specifically in the white-noise (amplified) region of the response spectrum, algebraic modal combination is still a matter of controversy, demonstrated e.g. by the NRC R.G. 1.92 requirement to take the absolute values of the modal responses in heuristic modal combination rules; whereas algebraic support combination is only allowed in conjunction with the envelope support response spectrum (ERS). Such regulatory requirements can lead to unrealistically high calculated responses e.g. in the coupled analysis of light secondary systems attached to heavy primary structures and in the decoupled analysis of systems when the centres of mass and stiffness do not coincide, or when the ERS is used. A new Generalised Algebraic Combination (GAC) methodology has been theoretically developed which allows practical algebraic modal and support combination over the whole frequency range of multiple support spectra. The present paper deals with the GAC-(A) i.e. the modal combination version in the white noise region of a single response spectrum and more specifically its time history integration validation, which shows that this new modal combination rule can satisfy any realistic conservatism that may be required by regulatory institutions. (orig.)

  20. A study of exercise modality and physical self-esteem in breast cancer survivors.

    Science.gov (United States)

    Musanti, Rita

    2012-02-01

    This study, theoretically based on the Exercise Self-Esteem Model, EXSEM, examined effects of exercise modality on physical and global self-esteem (PSE, GSE) in breast cancer survivors. The EXSEM posits GSE at the apex with PSE feeding into GSE. PSE has three subdomains: physical condition (PC), attractive body (AB), and physical strength (PS). The goals were to compare the effect of combination modality versus single-modality exercise on PSE and GSE and to explore the relationship between exercise modality and the subdomains of PSE. Survivors were randomly allocated to flexibility (F), aerobic (A), resistance (R), or aerobic plus resistance (AR), 12-wk, individualized, home-based exercise program. Pre/posttesting included submaximal treadmill test, six-repetition maximum chest press and leg press, YMCA bench press, shoulder/hip flexibility, and bioelectric impedance analysis body composition. Esteem measures were the Physical Self-Perception Profile and the Rosenberg Self-Esteem Scale. Forty-two women completed the study (F = 12, A = 10, R = 9, and AR = 11). Fitness improvements congruent with exercise modality were seen in all groups. PSE and GSE outcomes did not reveal a greater effect from the combination modality program, AR, compared with the single-modality programs A and R. The relationships between the single-modality groups and the subdomains of PC, PS, and AB were supported in the R group (PS and AB increased) and were partially supported in the A group (PC, not AB, increased). A single-modality R program significantly improved all domains of PSE, and participation in the A program improved the PC subdomain. The combination exercise program did not enhance PSE greater than the single-modality programs. EXSEM was a useful framework for exploring esteem in breast cancer survivors.

  1. Affirmation Modality in Bulgarian, Macedonian and Serbian

    Directory of Open Access Journals (Sweden)

    Marcin Grygiel

    2015-06-01

    Full Text Available Affirmation Modality in Bulgarian, Macedonian and Serbian In the case of affirmation modality the speakers transform their utterances by stressing or attributing a positive value as an additional component added to the semantic structure of a proposition. This type of affirmative polarization is triggered in opposition to negation or hypothetically negative contexts. The goal of the present paper is twofold: on the one hand to compare and contrast affirmative periphrastic constructions in Bulgarian, Macedonian and Serbian and, on the other hand, to ascertain what these constructions reveal regarding the organization of grammatical categories in general and the status of affirmation modality as a coherent and homogenous category with a linguistic validity.

  2. Complete proof systems for weighted modal logic

    DEFF Research Database (Denmark)

    Larsen, Kim G.; Mardare, Radu

    2014-01-01

    (WML) is a multi-modal logic that expresses qualitative and quantitative properties of WTSs. While WML has been studied in various contexts and for various application domains, no proof system has been developed for it. In this paper we solve this open problem and propose both weak-complete and strong......The weighted transition systems (WTS) considered in this paper are transition systems having both states and transitions labeled with real numbers: the state labels denote quantitative resources, while the transition labels denote costs of transitions in terms of resources. Weighted Modal Logic....... This work emphasizes a series of similarities between WML and the probabilistic/stochastic modal logics for Markov processes and Harsanyi type spaces, such as the use of particular infinitary rules to guarantee the strong-completeness....

  3. Comparison of particle-radiation-therapy modalities

    International Nuclear Information System (INIS)

    Fairchild, R.G.; Bond, V.P.

    1981-01-01

    The characteristics of dose distribution, beam alignment, and radiobiological advantages accorded to high LET radiation were reviewed and compared for various particle beam radiotherapeutic modalities (neutron, Auger electrons, p, π - , He, C, Ne, and Ar ions). Merit factors were evaluated on the basis of effective dose to tumor relative to normal tissue, linear energy transfer (LET), and dose localization, at depths of 1, 4, and 10 cm. In general, it was found that neutron capture therapy using an epithermal neutron beam provided the best merit factors available for depths up to 8 cm. The position of fast neutron therapy on the Merit Factor Tables was consistently lower than that of other particle modalities, and above only 60 Co. The largest body of clinical data exists for fast neutron therapy; results are considered by some to be encouraging. It then follows that if benefits with fast neutron therapy are real, additional gains are within reach with other modalities

  4. Tumour Debulking for Esophageal Cancer - Thermal Modalities

    Directory of Open Access Journals (Sweden)

    David Fleischer

    1992-01-01

    Full Text Available Esophageal cancer usually is discovered at a late stage and curative therapy seldom is possible. The prognosis is poor and most therapy is palliative. Endoscopic therapy commonly is employed; two common treatments involve thermal modalities. The Nd:YAG laser has been employed for 10 years and is effective in relieving obstruction in approximately 90% of cases. Re-ohstruction usually occurs in two to three months and repeat treatment may be necessary. Limitations to laser use include the fact that equipment is expensive and there are technical restrictions. An alternative thermal modality is the bipolar coagulation tumour probe which employs bipolar electrocoagulation. It is less expensive and, if the tumour is circumferential, tends to be easier to use. (It should not be used if the cancer is noncircumferential. The advantages and limitations of each modality are addressed.

  5. Nonrotational states of 165Er nuclei

    International Nuclear Information System (INIS)

    Bonch-Osmolovskaya, N.A.; Morozov, V.A.; Nesterenko, V.O.

    1985-01-01

    165 Er nucleus excited states have been analysed on the basis of available experimental data and calculations within the framework of a quasiparticle-phonon model. β-vibrational components of states are included into the calculations, the Pauli principle was taken account of consecutively. Taking account of the Pauli principle permitting to perform a more correct description of vibrational components resulted in a marked change of characteristics of a number of states especially in the case of 9/2 + [624]. The whole set of levels with 1/2 - [521], 297.4 keV; 1/2 - [530], 589.9 keV; 1/2 - [510], 920.7 keV; 3/2, 1/2 - [541], 1039 keV, is described satisfactorily. The calculation performed gives as a whole a better agreement with experiment as compared with earlier calculations of other authors

  6. Shapes of non-rotating nuclei

    International Nuclear Information System (INIS)

    Bengtsson, R.; Krumlinde, J.; Moeller, P.; Nix, J.R.; Zhang, J.

    1983-01-01

    We study nuclear potential-energy surfaces, ground-state masses and shapes calculated by use of a Yukawa-plus-exponential macroscopic model and a folded-Yukawa single-particle potential for 4023 nuclei ranging from 16 O to 279 112. We discuss extensively the transition from spherical to deformed shapes and study the relation between shape changes and the mass corresponding to the ground-state minimum. The calculated values for the ground-state mass and shape show good agreement with experimental data throughout the periodic system, but some discrepancies remain that deserve further study. We also discuss the effect of deformation on Gamow-Teller #betta#-strength functions

  7. Oblique impacts of non-rotating spheres

    Czech Academy of Sciences Publication Activity Database

    Chára, Zdeněk; Vlasák, Pavel; Kysela, Bohuš

    2014-01-01

    Roč. 21, č. 2 (2014), s. 97-102 ISSN 1802-1484 R&D Projects: GA ČR GA103/09/1718 Institutional support: RVO:67985874 Keywords : wake * particle trajectory * velocity field Subject RIV: BK - Fluid Dynamics

  8. Artificial Vision, New Visual Modalities and Neuroadaptation

    Directory of Open Access Journals (Sweden)

    Hilmi Or

    2012-01-01

    Full Text Available To study the descriptions from which artificial vision derives, to explore the new visual modalities resulting from eye surgeries and diseases, and to gain awareness of the use of machine vision systems for both enhancement of visual perception and better understanding of neuroadaptation. Science could not define until today what vision is. However, some optical-based systems and definitions have been established considering some factors for the formation of seeing. The best known system includes Gabor filter and Gabor patch which work on edge perception, describing the visual perception in the best known way. These systems are used today in industry and technology of machines, robots and computers to provide their "seeing". These definitions are used beyond the machinery in humans for neuroadaptation in new visual modalities after some eye surgeries or to improve the quality of some already known visual modalities. Beside this, “the blindsight” -which was not known to exist until 35 years ago - can be stimulated with visual exercises. Gabor system is a description of visual perception definable in machine vision as well as in human visual perception. This system is used today in robotic vision. There are new visual modalities which arise after some eye surgeries or with the use of some visual optical devices. Also, blindsight is a different visual modality starting to be defined even though the exact etiology is not known. In all the new visual modalities, new vision stimulating therapies using the Gabor systems can be applied. (Turk J Oph thal mol 2012; 42: 61-5

  9. Experimental Modal Test of the Laboratory Model of Steel Truss Structure

    Directory of Open Access Journals (Sweden)

    Kortiš Ján

    2016-12-01

    Full Text Available The experimental modal analysis is often used to validate the accuracy of dynamic numerical models. It is also a good tool to obtain valuable information about current condition of the structures that could help to determine residual lifetime. The quality of modal testing results is highly dependent on the proper estimation of the natural frequencies from the frequency response function. This article presents the experimental modal test of the laboratory steel structure in which the natural frequencies and mode shapes are determined.

  10. Established rheumatoid arthritis - new imaging modalities

    DEFF Research Database (Denmark)

    McQueen, Fiona M; Østergaard, Mikkel

    2007-01-01

    in real-time and facilitates diagnostic and therapeutic interventions such as joint aspiration and injection. Exciting experimental modalities are also being developed with the potential to provide not just morphological but functional imaging. Techniques such as positron emission tomography (PET......) and high-resolution computerized tomography. Erosions are very clearly depicted using these modalities and MRI also allows imaging of soft tissues with assessment of joint inflammation. High-resolution ultrasound is a convenient clinical technique for the assessment of erosions, synovitis and tenosynovitis...

  11. Nonoperative modalities to treat symptomatic cervical spondylosis.

    LENUS (Irish Health Repository)

    Hirpara, Kieran Michael

    2012-01-01

    Cervical spondylosis is a common and disabling condition. It is generally felt that the initial management should be nonoperative, and these modalities include physiotherapy, analgesia and selective nerve root injections. Surgery should be reserved for moderate to severe myelopathy patients who have failed a period of conservative treatment and patients whose symptoms are not adequately controlled by nonoperative means. A review of the literature supporting various modalities of conservative management is presented, and it is concluded that although effective, nonoperative treatment is labour intensive, requiring regular review and careful selection of medications and physical therapy on a case by case basis.

  12. Dorsal and ventral streams across sensory modalities

    Institute of Scientific and Technical Information of China (English)

    Anna Sedda; Federica Scarpina

    2012-01-01

    In this review,we describe the current models of dorsal and ventral streams in vision,audition and touch.Available theories take their first steps from the model of Milner and Goodale,which was developed to explain how human actions can be efficiently carried out using visual information.Since then,similar concepts have also been applied to other sensory modalities.We propose that advances in the knowledge of brain functioning can be achieved through models explaining action and perception patterns independently from sensory modalities.

  13. Combined modality treatment with radiotherapy and chemotherapy

    International Nuclear Information System (INIS)

    Tannock, I.F.; Toronto Univ., ON

    1989-01-01

    The present paper discusses some of the methodological issues which can confound the interpretation of clinical trials of combined modality treatment. It reviews some of the larger randomized trials which have evaluated combined modality treatment in cancers of the head and neck, lung, gastrointestinal tract and bladder. It concludes that adequate trials have yet to be performed in many of thses sites, but that at present, evidence for long-term benefit from adjunctivechemotherapy is meagre. Finally, it suggests some possible mechanisms which might heve limited the benefit of chemotherapy when added to radiation treatment. (Author). 87 refs.; 4 figs.; 4 tabs

  14. Response Modality Variations Affect Determinations of Children's Learning Styles.

    Science.gov (United States)

    Janowitz, Jeffrey M.

    The Swassing-Barbe Modality Index (SBMI) uses visual, auditory, and tactile inputs, but only reconstructed output, to measure children's modality strengths. In this experiment, the SBMI's three input modalities were crossed with two output modalities (spoken and drawn) in addition to the reconstructed standard to result in nine treatment…

  15. The Modality-Match Effect in Recognition Memory

    Science.gov (United States)

    Mulligan, Neil W.; Osborn, Katherine

    2009-01-01

    The modality-match effect in recognition refers to superior memory for words presented in the same modality at study and test. Prior research on this effect is ambiguous and inconsistent. The present study demonstrates that the modality-match effect is found when modality is rendered salient at either encoding or retrieval. Specifically, in…

  16. Computer-based image analysis in radiological diagnostics and image-guided therapy: 3D-Reconstruction, contrast medium dynamics, surface analysis, radiation therapy and multi-modal image fusion

    International Nuclear Information System (INIS)

    Beier, J.

    2001-01-01

    This book deals with substantial subjects of postprocessing and analysis of radiological image data, a particular emphasis was put on pulmonary themes. For a multitude of purposes the developed methods and procedures can directly be transferred to other non-pulmonary applications. The work presented here is structured in 14 chapters, each describing a selected complex of research. The chapter order reflects the sequence of the processing steps starting from artefact reduction, segmentation, visualization, analysis, therapy planning and image fusion up to multimedia archiving. In particular, this includes virtual endoscopy with three different scene viewers (Chap. 6), visualizations of the lung disease bronchiectasis (Chap. 7), surface structure analysis of pulmonary tumors (Chap. 8), quantification of contrast medium dynamics from temporal 2D and 3D image sequences (Chap. 9) as well as multimodality image fusion of arbitrary tomographical data using several visualization techniques (Chap. 12). Thus, the software systems presented cover the majority of image processing applications necessary in radiology and were entirely developed, implemented and validated in the clinical routine of a university medical school. (orig.) [de

  17. MODAL TRACKING of A Structural Device: A Subspace Identification Approach

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J. V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Franco, S. N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ruggiero, E. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Emmons, M. C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lopez, I. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stoops, L. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-03-20

    Mechanical devices operating in an environment contaminated by noise, uncertainties, and extraneous disturbances lead to low signal-to-noise-ratios creating an extremely challenging processing problem. To detect/classify a device subsystem from noisy data, it is necessary to identify unique signatures or particular features. An obvious feature would be resonant (modal) frequencies emitted during its normal operation. In this report, we discuss a model-based approach to incorporate these physical features into a dynamic structure that can be used for such an identification. The approach we take after pre-processing the raw vibration data and removing any extraneous disturbances is to obtain a representation of the structurally unknown device along with its subsystems that capture these salient features. One approach is to recognize that unique modal frequencies (sinusoidal lines) appear in the estimated power spectrum that are solely characteristic of the device under investigation. Therefore, the objective of this effort is based on constructing a black box model of the device that captures these physical features that can be exploited to “diagnose” whether or not the particular device subsystem (track/detect/classify) is operating normally from noisy vibrational data. Here we discuss the application of a modern system identification approach based on stochastic subspace realization techniques capable of both (1) identifying the underlying black-box structure thereby enabling the extraction of structural modes that can be used for analysis and modal tracking as well as (2) indicators of condition and possible changes from normal operation.

  18. Decentralized modal identification using sparse blind source separation

    International Nuclear Information System (INIS)

    Sadhu, A; Hazra, B; Narasimhan, S; Pandey, M D

    2011-01-01

    Popular ambient vibration-based system identification methods process information collected from a dense array of sensors centrally to yield the modal properties. In such methods, the need for a centralized processing unit capable of satisfying large memory and processing demands is unavoidable. With the advent of wireless smart sensor networks, it is now possible to process information locally at the sensor level, instead. The information at the individual sensor level can then be concatenated to obtain the global structure characteristics. A novel decentralized algorithm based on wavelet transforms to infer global structure mode information using measurements obtained using a small group of sensors at a time is proposed in this paper. The focus of the paper is on algorithmic development, while the actual hardware and software implementation is not pursued here. The problem of identification is cast within the framework of under-determined blind source separation invoking transformations of measurements to the time–frequency domain resulting in a sparse representation. The partial mode shape coefficients so identified are then combined to yield complete modal information. The transformations are undertaken using stationary wavelet packet transform (SWPT), yielding a sparse representation in the wavelet domain. Principal component analysis (PCA) is then performed on the resulting wavelet coefficients, yielding the partial mixing matrix coefficients from a few measurement channels at a time. This process is repeated using measurements obtained from multiple sensor groups, and the results so obtained from each group are concatenated to obtain the global modal characteristics of the structure

  19. Decentralized modal identification using sparse blind source separation

    Science.gov (United States)

    Sadhu, A.; Hazra, B.; Narasimhan, S.; Pandey, M. D.

    2011-12-01

    Popular ambient vibration-based system identification methods process information collected from a dense array of sensors centrally to yield the modal properties. In such methods, the need for a centralized processing unit capable of satisfying large memory and processing demands is unavoidable. With the advent of wireless smart sensor networks, it is now possible to process information locally at the sensor level, instead. The information at the individual sensor level can then be concatenated to obtain the global structure characteristics. A novel decentralized algorithm based on wavelet transforms to infer global structure mode information using measurements obtained using a small group of sensors at a time is proposed in this paper. The focus of the paper is on algorithmic development, while the actual hardware and software implementation is not pursued here. The problem of identification is cast within the framework of under-determined blind source separation invoking transformations of measurements to the time-frequency domain resulting in a sparse representation. The partial mode shape coefficients so identified are then combined to yield complete modal information. The transformations are undertaken using stationary wavelet packet transform (SWPT), yielding a sparse representation in the wavelet domain. Principal component analysis (PCA) is then performed on the resulting wavelet coefficients, yielding the partial mixing matrix coefficients from a few measurement channels at a time. This process is repeated using measurements obtained from multiple sensor groups, and the results so obtained from each group are concatenated to obtain the global modal characteristics of the structure.

  20. Modality-Driven Classification and Visualization of Ensemble Variance

    Energy Technology Data Exchange (ETDEWEB)

    Bensema, Kevin; Gosink, Luke; Obermaier, Harald; Joy, Kenneth I.

    2016-10-01

    Advances in computational power now enable domain scientists to address conceptual and parametric uncertainty by running simulations multiple times in order to sufficiently sample the uncertain input space. While this approach helps address conceptual and parametric uncertainties, the ensemble datasets produced by this technique present a special challenge to visualization researchers as the ensemble dataset records a distribution of possible values for each location in the domain. Contemporary visualization approaches that rely solely on summary statistics (e.g., mean and variance) cannot convey the detailed information encoded in ensemble distributions that are paramount to ensemble analysis; summary statistics provide no information about modality classification and modality persistence. To address this problem, we propose a novel technique that classifies high-variance locations based on the modality of the distribution of ensemble predictions. Additionally, we develop a set of confidence metrics to inform the end-user of the quality of fit between the distribution at a given location and its assigned class. We apply a similar method to time-varying ensembles to illustrate the relationship between peak variance and bimodal or multimodal behavior. These classification schemes enable a deeper understanding of the behavior of the ensemble members by distinguishing between distributions that can be described by a single tendency and distributions which reflect divergent trends in the ensemble.

  1. Refinement Checking on Parametric Modal Transition Systems

    DEFF Research Database (Denmark)

    Benes, Nikola; Kretínsky, Jan; Larsen, Kim Guldstrand

    2015-01-01

    Modal transition systems (MTS) is a well-studied specification formalism of reactive systems supporting a step-wise refinement methodology. Despite its many advantages, the formalism as well as its currently known extensions are incapable of expressing some practically needed aspects in the refin...

  2. Established rheumatoid arthritis - new imaging modalities

    DEFF Research Database (Denmark)

    McQueen, Fiona M; Østergaard, Mikkel

    2007-01-01

    New imaging modalities are assuming an increasingly important role in the investigation and management of rheumatoid arthritis. It is now possible to obtain information about all tissues within the joint in three dimensions using tomographic techniques such as magnetic resonance imaging (MRI...

  3. Nanomaterials Toxicity and Cell Death Modalities

    Directory of Open Access Journals (Sweden)

    Daniela De Stefano

    2012-01-01

    Full Text Available In the last decade, the nanotechnology advancement has developed a plethora of novel and intriguing nanomaterial application in many sectors, including research and medicine. However, many risks have been highlighted in their use, particularly related to their unexpected toxicity in vitro and in vivo experimental models. This paper proposes an overview concerning the cell death modalities induced by the major nanomaterials.

  4. Dual-Modality Breast Tomosynthesis1

    OpenAIRE

    Williams, Mark B.; Judy, Patricia G.; Gunn, Spencer; Majewski, Stanislaw

    2010-01-01

    Pilot clinical evaluation of this dual-modality tomosynthesis system suggests that it is a feasible and accurate method with which to detect and diagnose breast cancer and that specificity and positive predictive value can be improved by adding molecular breast imaging tomosynthesis to x-ray tomosynthesis.

  5. Sensor Placement for Modal Parameter Subset Estimation

    DEFF Research Database (Denmark)

    Ulriksen, Martin Dalgaard; Bernal, Dionisio; Damkilde, Lars

    2016-01-01

    The present paper proposes an approach for deciding on sensor placements in the context of modal parameter estimation from vibration measurements. The approach is based on placing sensors, of which the amount is determined a priori, such that the minimum Fisher information that the frequency resp...

  6. Learning Modalities--Should They Be Considered?

    Science.gov (United States)

    Jones, John Paul

    The author summarizes and reviews seven research studies which seek to determine the role of individual modal preference as related to learning to read. The seven studies are by Bateman (1968); Robinson (1968); Jones (1970); Bruininks (1968); Cripe (1966); de Hirsh, Jansky, and Langford (1966); and Bursuk (1971). Of these studies, only Bursuk…

  7. The Fourier modal method for aperiodic structures

    NARCIS (Netherlands)

    Pisarenco, M.; Maubach, J.M.L.; Setija, I.D.; Mattheij, R.M.M.

    2010-01-01

    This paper extends the area of application of the Fourier modal method from periodic structures to non-periodic ones illuminated under arbitrary angles. This is achieved by placing perfectly matched layers at the lateral boundaries and reformulating the problem in terms of a contrast field.

  8. Current diagnostic modalities for vulnerable plaque detection

    NARCIS (Netherlands)

    J.A. Schaar (Johannes); F. Mastik (Frits); E.S. Regar (Eveline); C.A. den Uil (Corstiaan); F.J.H. Gijsen (Frank); J.J. Wentzel (Jolanda); P.W.J.C. Serruys (Patrick); A.F.W. van der Steen (Ton)

    2007-01-01

    textabstractRupture of vulnerable plaques is the main cause of acute coronary syndrome and myocardial infarction. Identification of vulnerable plaques is therefore essential to enable the development of treatment modalities to stabilize such plaques. Several diagnostic methods are currently tested

  9. Computing modal dispersion characteristics of radially Asymmetric ...

    African Journals Online (AJOL)

    We developed a matrix theory that applies to with non-circular/circular but concentric layers fibers. And we compute the dispersion characteristics of radially unconventional fiber, known as Asymmetric Bragg fiber. An attempt has been made to determine how the modal characteristics change as circular Bragg fiber is ...

  10. Evidentiality, Epistemic Modality, and Epistemic Status

    Directory of Open Access Journals (Sweden)

    Rezeda Dilshatovna Shakirova

    2016-09-01

    Full Text Available The article discusses the interaction of evidentiality categories, typical of many Turkic, Finno-Ugric, Samoyed, certain Slavic, and other languages with the categories of epistemic modality, which is widely represented particularly in Germanic languages. The methodological framework of this study consists of the general philosophic, general scientific and private levels. The general philosophic methodology is based on the analytic philosophy, under the linguistic trend of which the language study was carried out to solve philosophic problems. The general scientific methodological bases of the study are related to the principle of identifying similarities and differences of the categories analyzed and the systematicity of description, whereas the descriptive method and techniques thereof are used primarily as the private-linguistic methods. In contrast to evidentiality, indicating the source of information, the epistemic modality marks different level of the information reliability. In the modern German language, the categories studied have a zone of intersection in terms of community within the means of expression, to which modal words and modal verbs as well as the verb scheinen can be primarily related. However, in the modern German language, there is no question of the category of evidentiality in the plane, within which it is currently being studied basing on the material of those languages, to the fragment of the grammatical system of which it is primarily inherent. As a rule, the semantics of evidentiality in these languages provides no information on the degree of reliability of the source of knowledge. To overcome the contradiction of such nature, this work suggests paying attention to the category of epistemic status of an utterance, the semantic structure of which is wider than evidentiality and epistemic modality and includes the level of reliability of the source of knowledge along with the designation thereof. In today's German

  11. Conflict when making decisions about dialysis modality.

    Science.gov (United States)

    Chen, Nien-Hsin; Lin, Yu-Ping; Liang, Shu-Yuan; Tung, Heng-Hsin; Tsay, Shiow-Luan; Wang, Tsae-Jyy

    2018-01-01

    To explore decisional conflict and its influencing factors on choosing dialysis modality in patients with end-stage renal diseases. The influencing factors investigated include demographics, predialysis education, dialysis knowledge, decision self-efficacy and social support. Making dialysis modality decisions can be challenging for patients with end-stage renal diseases; there are pros and cons to both haemodialysis and peritoneal dialysis. Patients are often uncertain as to which one will be the best alternative for them. This decisional conflict increases the likelihood of making a decision that is not based on the patient's values or preferences and may result in undesirable postdecisional consequences. Addressing factors predisposing patients to decisional conflict helps to facilitate informed decision-making and then to improve healthcare quality. A predictive correlational cross-sectional study design was used. Seventy patients were recruited from the outpatient dialysis clinics of two general hospitals in Taiwan. Data were collected with study questionnaires, including questions on demographics, dialysis modality and predialysis education, the Dialysis Knowledge Scale, the Decision Self-Efficacy scale, the Social Support Scale, and the Decisional Conflict Scale. The mean score on the Decisional Conflict Scale was 29.26 (SD = 22.18). Decision self-efficacy, dialysis modality, predialysis education, professional support and dialysis knowledge together explained 76.4% of the variance in decisional conflict. Individuals who had lower decision self-efficacy, did not receive predialysis education on both haemodialysis and peritoneal dialysis, had lower dialysis knowledge and perceived lower professional support reported higher decisional conflict on choosing dialysis modality. When providing decisional support to predialysis stage patients, practitioners need to increase patients' decision self-efficacy, provide both haemodialysis and peritoneal dialysis

  12. Using Response Surface Methods to Correlate the Modal Test of an Inflatable Test Article

    Science.gov (United States)

    Gupta, Anju

    2013-01-01

    This paper presents a practical application of response surface methods (RSM) to correlate a finite element model of a structural modal test. The test article is a quasi-cylindrical inflatable structure which primarily consists of a fabric weave, with an internal bladder and metallic bulkheads on either end. To mitigate model size, the fabric weave was simplified by representing it with shell elements. The task at hand is to represent the material behavior of the weave. The success of the model correlation is measured by comparing the four major modal frequencies of the analysis model to the four major modal frequencies of the test article. Given that only individual strap material properties were provided and material properties of the overall weave were not available, defining the material properties of the finite element model became very complex. First it was necessary to determine which material properties (modulus of elasticity in the hoop and longitudinal directions, shear modulus, Poisson's ratio, etc.) affected the modal frequencies. Then a Latin Hypercube of the parameter space was created to form an efficiently distributed finite case set. Each case was then analyzed with the results input into RSM. In the resulting response surface it was possible to see how each material parameter affected the modal frequencies of the analysis model. If the modal frequencies of the analysis model and its corresponding parameters match the test with acceptable accuracy, it can be said that the model correlation is successful.

  13. A tri-modality image fusion method for target delineation of brain tumors in radiotherapy.

    Directory of Open Access Journals (Sweden)

    Lu Guo

    Full Text Available To develop a tri-modality image fusion method for better target delineation in image-guided radiotherapy for patients with brain tumors.A new method of tri-modality image fusion was developed, which can fuse and display all image sets in one panel and one operation. And a feasibility study in gross tumor volume (GTV delineation using data from three patients with brain tumors was conducted, which included images of simulation CT, MRI, and 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET examinations before radiotherapy. Tri-modality image fusion was implemented after image registrations of CT+PET and CT+MRI, and the transparency weight of each modality could be adjusted and set by users. Three radiation oncologists delineated GTVs for all patients using dual-modality (MRI/CT and tri-modality (MRI/CT/PET image fusion respectively. Inter-observer variation was assessed by the coefficient of variation (COV, the average distance between surface and centroid (ADSC, and the local standard deviation (SDlocal. Analysis of COV was also performed to evaluate intra-observer volume variation.The inter-observer variation analysis showed that, the mean COV was 0.14(± 0.09 and 0.07(± 0.01 for dual-modality and tri-modality respectively; the standard deviation of ADSC was significantly reduced (p<0.05 with tri-modality; SDlocal averaged over median GTV surface was reduced in patient 2 (from 0.57 cm to 0.39 cm and patient 3 (from 0.42 cm to 0.36 cm with the new method. The intra-observer volume variation was also significantly reduced (p = 0.00 with the tri-modality method as compared with using the dual-modality method.With the new tri-modality image fusion method smaller inter- and intra-observer variation in GTV definition for the brain tumors can be achieved, which improves the consistency and accuracy for target delineation in individualized radiotherapy.

  14. Visual and cross-modal cues increase the identification of overlapping visual stimuli in Balint's syndrome.

    Science.gov (United States)

    D'Imperio, Daniela; Scandola, Michele; Gobbetto, Valeria; Bulgarelli, Cristina; Salgarello, Matteo; Avesani, Renato; Moro, Valentina

    2017-10-01

    Cross-modal interactions improve the processing of external stimuli, particularly when an isolated sensory modality is impaired. When information from different modalities is integrated, object recognition is facilitated probably as a result of bottom-up and top-down processes. The aim of this study was to investigate the potential effects of cross-modal stimulation in a case of simultanagnosia. We report a detailed analysis of clinical symptoms and an 18 F-fluorodeoxyglucose (FDG) brain positron emission tomography/computed tomography (PET/CT) study of a patient affected by Balint's syndrome, a rare and invasive visual-spatial disorder following bilateral parieto-occipital lesions. An experiment was conducted to investigate the effects of visual and nonvisual cues on performance in tasks involving the recognition of overlapping pictures. Four modalities of sensory cues were used: visual, tactile, olfactory, and auditory. Data from neuropsychological tests showed the presence of ocular apraxia, optic ataxia, and simultanagnosia. The results of the experiment indicate a positive effect of the cues on the recognition of overlapping pictures, not only in the identification of the congruent valid-cued stimulus (target) but also in the identification of the other, noncued stimuli. All the sensory modalities analyzed (except the auditory stimulus) were efficacious in terms of increasing visual recognition. Cross-modal integration improved the patient's ability to recognize overlapping figures. However, while in the visual unimodal modality both bottom-up (priming, familiarity effect, disengagement of attention) and top-down processes (mental representation and short-term memory, the endogenous orientation of attention) are involved, in the cross-modal integration it is semantic representations that mainly activate visual recognition processes. These results are potentially useful for the design of rehabilitation training for attentional and visual-perceptual deficits.

  15. Bi-objective optimization for multi-modal transportation routing planning problem based on Pareto optimality

    Directory of Open Access Journals (Sweden)

    Yan Sun

    2015-09-01

    Full Text Available Purpose: The purpose of study is to solve the multi-modal transportation routing planning problem that aims to select an optimal route to move a consignment of goods from its origin to its destination through the multi-modal transportation network. And the optimization is from two viewpoints including cost and time. Design/methodology/approach: In this study, a bi-objective mixed integer linear programming model is proposed to optimize the multi-modal transportation routing planning problem. Minimizing the total transportation cost and the total transportation time are set as the optimization objectives of the model. In order to balance the benefit between the two objectives, Pareto optimality is utilized to solve the model by gaining its Pareto frontier. The Pareto frontier of the model can provide the multi-modal transportation operator (MTO and customers with better decision support and it is gained by the normalized normal constraint method. Then, an experimental case study is designed to verify the feasibility of the model and Pareto optimality by using the mathematical programming software Lingo. Finally, the sensitivity analysis of the demand and supply in the multi-modal transportation organization is performed based on the designed case. Findings: The calculation results indicate that the proposed model and Pareto optimality have good performance in dealing with the bi-objective optimization. The sensitivity analysis also shows the influence of the variation of the demand and supply on the multi-modal transportation organization clearly. Therefore, this method can be further promoted to the practice. Originality/value: A bi-objective mixed integer linear programming model is proposed to optimize the multi-modal transportation routing planning problem. The Pareto frontier based sensitivity analysis of the demand and supply in the multi-modal transportation organization is performed based on the designed case.

  16. Mental Health Disorder Therapeutic Modalities Modified for the GMS.

    Science.gov (United States)

    Sumneangsanor, Tipsuda; Vuthiarpa, Sararud; Somprasert, Chomchueun

    2017-12-01

    Mental health disorders can affect physical and psychological behaviors. The people of the Greater Mekong Subregion (GMS) have a high risk of mental health disorders, such as depression, stress, and substance abuse be-cause the people in this region are trafficked for forced sex work and various forms of forced labor. In these situations, vic-tims often endure violence and abuse from trafficking recruiters, employers, and other individuals. The purposes of this study were to identify the elements characterizing mental health disorders, especially in terms of depression, stress, and sub-stance abuse, and to identify the treatment modalities for mental health disorders in the GMS. The researcher undertook a comparative analysis of the literature, reviews of epidemiological studies and mental disorder therapies, and overviews of previous research studies, were used to generate a synthesis of the existing knowledge of the mental disorder therapeutic modalities. Regarding the search methods, the data from the electronic databases PubMed, PsycINFO, Dynamed and ScienceDirect were supplemented with a manual reference search covering relevant studies from 2005 to 2016. Thirty-one papers were included in the review of elements characterizing mental health disorders, especially in terms of depression, stress, and substance abuse, and to identify the treatment modalities for mental health disorders in the GMS. Nine papers defined characterizing mental health disorders, in terms of depression, stress, and substance abuse. Twenty-two papers showed the treatment modalities for mental health disorders that the treatment was effective, these in-cluded pharmacological treatments and psychological treatments, such as mindfulness-based cognitive therapy, biofeedback, and music therapy. Useful guidance can be provided for the prevention and treatment of mental health disorders, and for the care of people in the Greater Mekong Subregion. The finding of this review confirms the

  17. On structural inelasticity of modal substitution in freight transport

    DEFF Research Database (Denmark)

    Rich, Jeppe; Kveiborg, Ole; Overgård, Christian Hansen

    2011-01-01

    alternative available. The paper investigates the magnitude of this ‘‘structural inelasticity” of modal substitution in freight transport due to a sparser layout of rail and ship-based freight networks compared to road. In the analysis we use a recent Scandinavian freight demand model covering more than 800...... zones. We find that the structural inelasticity is very significant – in particular for transportation over less than 500 km. Moreover, the inelasticity varies greatly with commodity groups and between OD pairs, and it depends strongly on the port and rail infrastructure. The results suggest that pure...

  18. Simple design of slanted grating with simplified modal method.

    Science.gov (United States)

    Li, Shubin; Zhou, Changhe; Cao, Hongchao; Wu, Jun

    2014-02-15

    A simplified modal method (SMM) is presented that offers a clear physical image for subwavelength slanted grating. The diffraction characteristic of the slanted grating under Littrow configuration is revealed by the SMM as an equivalent rectangular grating, which is in good agreement with rigorous coupled-wave analysis. Based on the equivalence, we obtained an effective analytic solution for simplifying the design and optimization of a slanted grating. It offers a new approach for design of the slanted grating, e.g., a 1×2 beam splitter can be easily designed. This method should be helpful for designing various new slanted grating devices.

  19. The Role of Modal Verbs in Research Papers in the Field of Logistics

    Directory of Open Access Journals (Sweden)

    Polona Vičič

    2016-08-01

    Full Text Available Research papers, an essential vehicle for disseminating new knowledge and findings, have long been valued for their linguistic objectivity and impersonality. However, more recent approaches to research paper writing suggest that authors should also take an “argumentative position” (White, 2003 by projecting their stance and encouraging the readers to actively engage in the process of reading and evaluating the text (Hyland, 2005; Scollon, 1994. An important linguistic feature, frequently employed for both objective and subjective presentation of claims, is modality and within it modal verbs, which through their modal meanings express different communicative functions. In recognition of genre- and discipline-specific norms, the present paper will focus on quantitative and qualitative analysis of modal verbs and their meanings and functions in logistics research papers, whereby the ultimate goal is to show what practical implications the study’s results may have for the teaching of English to students of logistics.

  20. Modality shift effects mimic multisensory interactions

    DEFF Research Database (Denmark)

    Gondan, Matthias; Vorberg, D.; Greenlee, M.W.

    2007-01-01

    be avoided using an additional tactile stimulus (T) and evaluating the ERP difference (T + TAV) - (TA + TV). A second possible confound is the modality shift effect (MSE): for example, the auditory N1 is increased if an auditory stimulus follows a visual stimulus, whereas it is smaller if the modality......A frequent approach to study interactions of the auditory and the visual system is to measure event-related potentials (ERPs) to auditory, visual, and auditory-visual stimuli (A, V, AV). A nonzero result of the AV - (A + V) comparison indicates that the sensory systems interact at a specific...... processing stage. Two possible biases weaken the conclusions drawn by this approach: first, subtracting two ERPs from one requires that A, V, and AV do not share any common activity. We have shown before (Gondan and Röder in Brain Res 1073-1074:389-397, 2006) that the problem of common activity can...

  1. Kinetic Study of Curcumin on Modal Fabric

    Directory of Open Access Journals (Sweden)

    Abu Naser Md. Ahsanul Haque

    2018-03-01

    Full Text Available A kinetic study of curcumin on modal fabric was carried out using an initial dye concentration of 1 g/L at three different temperatures, 70 °C, 85 °C and 100 °C, at pH 7 and an material to liquor ratio of 1:20. Pseudo first-order and pseudo second-order kinetics were applied, and it was found that the adsorption kinetics of curcumin on modal fabric matched the pseudo second-order kinetic model. The activation energy was found to be equal to 71.14 kJ/mol, while the enthalpy and entropy of activation were 68.16 kJ/mol and –66.02 J/molK respectively.

  2. MOSFET dosimetry on modern radiation oncology modalities

    International Nuclear Information System (INIS)

    Rosenfeld, A.B.

    2002-01-01

    The development of MOSFET dosimetry is presented with an emphasis on the development of a scanning MOSFET dosimetry system for modern radiation oncology modalities. Fundamental aspects of MOSFETs in relation to their use as dosemeters are briefly discussed. The performance of MOSFET dosemeters in conformal radiotherapy, hadron therapy, intensity-modulated radiotherapy and microbeam radiation therapy is compared with other dosimetric techniques. In particular the application of MOSFET dosemeters in the characterisation and quality assurance of the steep dose gradients associated with the penumbra of some modern radiation oncology modalities is investigated. A new in vivo, on-line, scanning MOSFET read out system is also presented. The system has the ability to read out multiple MOSFET dosemeters with excellent spatial resolution and temperature stability and minimal slow border trapping effects. (author)

  3. The life trajectories modality of oral history

    Directory of Open Access Journals (Sweden)

    Rita de Cássia Gonçalves

    2007-05-01

    Full Text Available This article seeks to explore the potential of qualitative research. It presents the life trajectory modality of the oral history method, to discuss the possibility of its utilization in scientific research in the Social Work profession. The epistemological foundations of oral history are discussed to establish its scientific character. The life trajectories modality is presented as a historic and social construction that utilizes different interview techniques to give voice to previously invisible subjects, indicating the principal phases of the methodological procedures used in this approach. The conclusions highlight the importance of the construction of this model and its projection as a research proposal that implies a process of understanding and analyzing the social universes that are contextualized and interconnected, considering the realities of the life trajectories of the subjects studied.

  4. Deception Detection, Transmission, & Modality in Age & Sex

    Directory of Open Access Journals (Sweden)

    Charlotte Dorothy Sweeney

    2014-06-01

    Full Text Available This study is the first to create and use spontaneous (i.e. unrehearsed pro-social lies in an ecological setting. Creation of the stimuli involved fifty-one older adult and forty-four college student senders who lied authentically in that their lies were spontaneous in the service of protecting a research assistant. In the main study, seventy-seven older adult and eighty-four college raters attempted to detect lies in the older adult and college senders in three modalities: audio, visual, and audiovisual. Raters of both age groups were best at detecting lies in the audiovisual and worst in the visual modalities. Overall, college students were better detectors than older adults. There was an age-matching effect for college students but not for older adults. Older adult males were the hardest to detect. The older the adult was the worse the ability to detect deception.

  5. Breast Cancer Screening, Mammography, and Other Modalities.

    Science.gov (United States)

    Fiorica, James V

    2016-12-01

    This article is an overview of the modalities available for breast cancer screening. The modalities discussed include digital mammography, digital breast tomosynthesis, breast ultrasonography, magnetic resonance imaging, and clinical breast examination. There is a review of pertinent randomized controlled trials, studies and meta-analyses which contributed to the evolution of screening guidelines. Ultimately, 5 major medical organizations formulated the current screening guidelines in the United States. The lack of consensus in these guidelines represents an ongoing controversy about the optimal timing and method for breast cancer screening in women. For mammography screening, the Breast Imaging Reporting and Data System lexicon is explained which corresponds with recommended clinical management. The presentation and discussion of the data in this article are designed to help the clinician individualize breast cancer screening for each patient.

  6. Focused labeled proof systems for modal logic

    OpenAIRE

    Miller , Dale; Volpe , Marco

    2015-01-01

    International audience; Focused proofs are sequent calculus proofs that group inference rules into alternating positive and negative phases. These phases can then be used to define macro-level inference rules from Gentzen's original and tiny introduction and structural rules. We show here that the inference rules of labeled proof systems for modal logics can similarly be described as pairs of such phases within the LKF focused proof system for first-order classical logic. We consider the syst...

  7. A Transgenic Tri-Modality Reporter Mouse

    OpenAIRE

    Yan, Xinrui; Ray, Pritha; Paulmurugan, Ramasamy; Tong, Ricky; Gong, Yongquan; Sathirachinda, Ataya; Wu, Joseph C.; Gambhir, Sanjiv S.

    2013-01-01

    Transgenic mouse with a stably integrated reporter gene(s) can be a valuable resource for obtaining uniformly labeled stem cells, tissues, and organs for various applications. We have generated a transgenic mouse model that ubiquitously expresses a tri-fusion reporter gene (fluc2-tdTomato-ttk) driven by a constitutive chicken β-actin promoter. This "Tri-Modality Reporter Mouse" system allows one to isolate most cells from this donor mouse and image them for bioluminescent (fluc2), fluorescent...

  8. Treatment modalities of palatal impacted canines

    OpenAIRE

    Dimova, Cena; Papakoca, Kiro; Ristoska, Sonja; Kovacevska, Ivona

    2012-01-01

    Introduction: The orthodontic treatment of impacted maxillary canine remains a challenge to today’s clinicians. The treatment of this clinical entity usually involves surgical exposure of the impacted tooth, followed by orthodontic traction to guide and align it into the dental arch. The impacted palatal canine requires a combination of both treatment modalities: orthodontic management and oral surgical treatment. Two types of approach are commonly used: simple exposure, or exposure with brac...

  9. A method for experimental modal separation

    Science.gov (United States)

    Hallauer, W. L., Jr.

    1977-01-01

    A method is described for the numerical simulation of multiple-shaker modal survey testing using simulated experimental data to optimize the shaker force-amplitude distribution for the purpose of isolating individual modes of vibration. Inertia, damping, stiffness, and model data are stored on magnetic disks, available by direct access to the interactive FORTRAN programs which perform all computations required by this relative force amplitude distribution method.

  10. Modality-specificity of Selective Attention Networks

    OpenAIRE

    Stewart, Hannah J.; Amitay, Sygal

    2015-01-01

    Objective: To establish the modality specificity and generality of selective attention networks. Method: Forty-eight young adults completed a battery of four auditory and visual selective attention tests based upon the Attention Network framework: the visual and auditory Attention Network Tests (vANT, aANT), the Test of Everyday Attention (TEA), and the Test of Attention in Listening (TAiL). These provided independent measures for auditory and visual alerting, orienting, and conflict resoluti...

  11. Imaging Breast Density: Established and Emerging Modalities

    Directory of Open Access Journals (Sweden)

    Jeon-Hor Chen

    2015-12-01

    Full Text Available Mammographic density has been proven as an independent risk factor for breast cancer. Women with dense breast tissue visible on a mammogram have a much higher cancer risk than women with little density. A great research effort has been devoted to incorporate breast density into risk prediction models to better estimate each individual’s cancer risk. In recent years, the passage of breast density notification legislation in many states in USA requires that every mammography report should provide information regarding the patient’s breast density. Accurate definition and measurement of breast density are thus important, which may allow all the potential clinical applications of breast density to be implemented. Because the two-dimensional mammography-based measurement is subject to tissue overlapping and thus not able to provide volumetric information, there is an urgent need to develop reliable quantitative measurements of breast density. Various new imaging technologies are being developed. Among these new modalities, volumetric mammographic density methods and three-dimensional magnetic resonance imaging are the most well studied. Besides, emerging modalities, including different x-ray–based, optical imaging, and ultrasound-based methods, have also been investigated. All these modalities may either overcome some fundamental problems related to mammographic density or provide additional density and/or compositional information. The present review article aimed to summarize the current established and emerging imaging techniques for the measurement of breast density and the evidence of the clinical use of these density methods from the literature.

  12. ADMultiImg: a novel missing modality transfer learning based CAD system for diagnosis of MCI due to AD using incomplete multi-modality imaging data

    Science.gov (United States)

    Liu, Xiaonan; Chen, Kewei; Wu, Teresa; Weidman, David; Lure, Fleming; Li, Jing

    2018-02-01

    Alzheimer's Disease (AD) is the most common cause of dementia and currently has no cure. Treatments targeting early stages of AD such as Mild Cognitive Impairment (MCI) may be most effective to deaccelerate AD, thus attracting increasing attention. However, MCI has substantial heterogeneity in that it can be caused by various underlying conditions, not only AD. To detect MCI due to AD, NIA-AA published updated consensus criteria in 2011, in which the use of multi-modality images was highlighted as one of the most promising methods. It is of great interest to develop a CAD system based on automatic, quantitative analysis of multi-modality images and machine learning algorithms to help physicians more adequately diagnose MCI due to AD. The challenge, however, is that multi-modality images are not universally available for many patients due to cost, access, safety, and lack of consent. We developed a novel Missing Modality Transfer Learning (MMTL) algorithm capable of utilizing whatever imaging modalities are available for an MCI patient to diagnose the patient's likelihood of MCI due to AD. Furthermore, we integrated MMTL with radiomics steps including image processing, feature extraction, and feature screening, and a post-processing for uncertainty quantification (UQ), and developed a CAD system called "ADMultiImg" to assist clinical diagnosis of MCI due to AD using multi-modality images together with patient demographic and genetic information. Tested on ADNI date, our system can generate a diagnosis with high accuracy even for patients with only partially available image modalities (AUC=0.94), and therefore may have broad clinical utility.

  13. Does the quality of radiation therapy (RT) impact upon outcome in the tri-modality treatment of stage IIIA(N2) non-small cell lung cancer (NSCLC)?: Analysis of cancer and leukemia group B (CALGB) protocol 8935

    International Nuclear Information System (INIS)

    Kumar, P.; Herndon, J.; Glicksman, A.; Eaton, W.; Langer, M.; Kass, F.C.; Seagren, S.; Green, M.; Sugarbaker, D.J.

    1996-01-01

    Purpose/Objective: The impact of the adequacy of portal fields and the total dose of RT upon pattern of local failure and survival was analyzed. Materials and Methods: Seventy-four patients with pathological stage IIIA(N 2 ) NSCLC were enrolled to a sequential tri-modality protocol consisting of induction chemotherapy [cisplatin(P) at 100 mg/m 2 on days 1,29 and vinblastine(V) 5 mg/m 2 weekly x 5] followed by thoracotomy. Patients with resected disease received an additional two cycles of the same PV followed by thoracic RT. Patients with completely resected disease were treated to 54 Gy while those with incompletely resected disease (i.e., positive margins and/or positive highest sampled mediastinal lymph node) received 59.4 Gy at 1.8 Gy/fraction (fx) once daily. Following protocol therapy, the adequacy of portal fields and total dose of RT was independently peer reviewed by a committee of CALGB Radiation Oncologists under the auspices of the Quality Assurance Review Center (QARC) in Providence, RI. A major deviation was scored if the radiation portal 'cut through' the required target volume and/or if the total radiation dose was greater than +/-10% from the protocol. Results: Thirty-three of 74 patients completed the full adjuvant protocol treatment including post-operative RT. Among patients undergoing complete vs. incomplete resection, no significant difference in 2-year post-RT failure-free survival (FFS) [48% vs. 17%, respectively, p .13] or overall survival (OS) [43% vs. 50%, respectively, p = .27] was evident between the two resection groups. Pattern of first failure among these 33 patients was as follows: Local (L) only = 1(5%), L/Distant (D) 6(28%), D only = 14(67%), p .99). Conclusion: In our study, thoracic RT delivered according to protocol requirements did not affect either pattern of local failure or survival in the tri-modality treatment of pathological stage IIIA(N 2 ) NSCLC. However, these findings could also reflect the sample size of our

  14. Correlation Results for a Mass Loaded Vehicle Panel Test Article Finite Element Models and Modal Survey Tests

    Science.gov (United States)

    Maasha, Rumaasha; Towner, Robert L.

    2012-01-01

    High-fidelity Finite Element Models (FEMs) were developed to support a recent test program at Marshall Space Flight Center (MSFC). The FEMs correspond to test articles used for a series of acoustic tests. Modal survey tests were used to validate the FEMs for five acoustic tests (a bare panel and four different mass-loaded panel configurations). An additional modal survey test was performed on the empty test fixture (orthogrid panel mounting fixture, between the reverb and anechoic chambers). Modal survey tests were used to test-validate the dynamic characteristics of FEMs used for acoustic test excitation. Modal survey testing and subsequent model correlation has validated the natural frequencies and mode shapes of the FEMs. The modal survey test results provide a basis for the analysis models used for acoustic loading response test and analysis comparisons

  15. Automated Modal Parameter Estimation of Civil Engineering Structures

    DEFF Research Database (Denmark)

    Andersen, Palle; Brincker, Rune; Goursat, Maurice

    In this paper the problems of doing automatic modal parameter extraction of ambient excited civil engineering structures is considered. Two different approaches for obtaining the modal parameters automatically are presented: The Frequency Domain Decomposition (FDD) technique and a correlation...

  16. TACT: A Set of MSC/PATRAN- and MSC/NASTRAN- based Modal Correlation Tools

    Science.gov (United States)

    Marlowe, Jill M.; Dixon, Genevieve D.

    1998-01-01

    This paper describes the functionality and demonstrates the utility of the Test Analysis Correlation Tools (TACT), a suite of MSC/PATRAN Command Language (PCL) tools which automate the process of correlating finite element models to modal survey test data. The initial release of TACT provides a basic yet complete set of tools for performing correlation totally inside the PATRAN/NASTRAN environment. Features include a step-by-step menu structure, pre-test accelerometer set evaluation and selection, analysis and test result export/import in Universal File Format, calculation of frequency percent difference and cross-orthogonality correlation results using NASTRAN, creation and manipulation of mode pairs, and five different ways of viewing synchronized animations of analysis and test modal results. For the PATRAN-based analyst, TACT eliminates the repetitive, time-consuming and error-prone steps associated with transferring finite element data to a third-party modal correlation package, which allows the analyst to spend more time on the more challenging task of model updating. The usefulness of this software is presented using a case history, the correlation for a NASA Langley Research Center (LaRC) low aspect ratio research wind tunnel model. To demonstrate the improvements that TACT offers the MSC/PATRAN- and MSC/DIASTRAN- based structural analysis community, a comparison of the modal correlation process using TACT within PATRAN versus external third-party modal correlation packages is presented.

  17. Comparison of sine dwell and broadband methods for modal testing

    Science.gov (United States)

    Chen, Jay-Chung

    1989-01-01

    The objectives of modal tests for large complex spacecraft structural systems are outlined. The comparison criteria for the modal test methods, namely, the broadband excitation and the sine dwell methods, are established. Using the Galileo spacecraft modal test and the Centaur G Prime upper stage vehicle modal test as examples, the relative advantage or disadvantage of each method is examined. The usefulness or shortcomings of the methods are given from a practical engineering viewpoint.

  18. On sine dwell or broadband methods for modal testing

    Science.gov (United States)

    Chen, Jay-Chung; Wada, Ben K.

    1987-01-01

    For large, complex spacecraft structural systems, the objectives of the modal test are outlined. Based on these objectives, the comparison criteria for the modal test methods, namely, the broadband excitation and the sine dwell methods are established. Using the Galileo spacecraft modal test and the Centaur G Prime upper stage vehicle modal test as examples, the relative advantages or disadvantages of each method are examined. The usefulness or shortcoming of the methods are given from a practicing engineer's view point.

  19. Converging modalities ground abstract categories: the case of politics.

    Science.gov (United States)

    Farias, Ana Rita; Garrido, Margarida V; Semin, Gün R

    2013-01-01

    Three studies are reported examining the grounding of abstract concepts across two modalities (visual and auditory) and their symbolic representation. A comparison of the outcomes across these studies reveals that the symbolic representation of political concepts and their visual and auditory modalities is convergent. In other words, the spatial relationships between specific instances of the political categories are highly overlapping across the symbolic, visual and auditory modalities. These findings suggest that abstract categories display redundancy across modal and amodal representations, and are multimodal.

  20. Modeling of Temperature Effect on Modal Frequency of Concrete Beam Based on Field Monitoring Data

    Directory of Open Access Journals (Sweden)

    Wenchen Shan

    2018-01-01

    Full Text Available Temperature variation has been widely demonstrated to produce significant effect on modal frequencies that even exceed the effect of actual damage. In order to eliminate the temperature effect on modal frequency, an effective method is to construct quantitative models which accurately predict the modal frequency corresponding to temperature variation. In this paper, principal component analysis (PCA is conducted on the temperatures taken from all embedded thermocouples for extracting input parameters of regression models. Three regression-based numerical models using multiple linear regression (MLR, back-propagation neural network (BPNN, and support vector regression (SVR techniques are constructed to capture the relationships between modal frequencies and temperature distributions from measurements of a concrete beam during a period of forty days of monitoring. A comparison with respect to the performance of various optimally configured regression models has been performed on measurement data. Results indicate that the SVR exhibits a better reproduction and prediction capability than BPNN and MLR models for predicting the modal frequencies with respect to nonuniformly distributed temperatures. It is succeeded that temperature effects on modal frequencies can be effectively eliminated based on the optimally formulated SVR model.