De Factorisatione Numerorum I : An Analytic Approach to Subexponential Factoring
Sica, Francesco
2009-01-01
We introduce a novel glance at factoring. In this work, we are chiefly concerned with the asymptotic aspect of the method, as we will show that this approach \\emph{almost} allows to deterministically factor a RSA modulus $N=pq$ in $O\\bigl(\\exp({\\log^\\epsilon N})\\bigr)$ bit operations for any $\\epsilon>0$. An important feature of this approach is that any bound is absolutely proven and does not rely on any assumption. The technique broached here departs from any know (at least to the author) factoring method. It is based on the study of carefully selected multiplicative functions in order to approximate them at $N$. Using their generating functions, expressed in terms of the Riemann zeta function, together with their functional equations, we derive an analytic identity which involves the computation of a family of series, which we call the \\emph{singular series} (as they embody an arithmetic information in analytic disguise), depending "minimally" on $N$. We finally show how the approximate computation of a ma...
A Factor Analytic Approach to Symptom Patterns in Dementia
Directory of Open Access Journals (Sweden)
Lars Gustafson
2011-01-01
Full Text Available Previous publications have shown a high diagnostic sensitivity and specificity of three short clinical rating scales for Alzheimer's disease (AD, frontotemporal dementia (FTD, and vascular dementia (VaD validated against neuropathological (NP diagnoses. In this study, the aim was to perform an exploratory factor analysis of the items in these clinical rating scales. The study included 190 patients with postmortem diagnoses of AD (n=74, VaD (n=33, mixed AD/VaD (n=31, or FTD (n=52. The factor analysis produced three strong factors. Factor 1 contained items describing cerebrovascular disease, similar to the Hachinski Ischemic Score. Factor 2 enclosed major clinical characteristics of FTD, and factor 3 showed a striking similarity to the AD scale. A fourth symptom cluster was described by perception and expression of emotions. The factor analyses strongly support the construct validity of the diagnostic rating scales.
The structure of temperament in preschoolers: a two-stage factor analytic approach.
Dyson, Margaret W; Olino, Thomas M; Durbin, C Emily; Goldsmith, H Hill; Klein, Daniel N
2012-02-01
The structure of temperament traits in young children has been the subject of extensive debate, with separate models proposing different trait dimensions. This research has relied almost exclusively on parent-report measures. The present study used an alternative approach, a laboratory observational measure, to explore the structure of temperament in preschoolers. A 2-stage factor analytic approach, exploratory factor analyses (n = 274) followed by confirmatory factor analyses (n = 276), was used. We retrieved an adequately fitting model that consisted of 5 dimensions: Sociability, Positive Affect/Interest, Dysphoria, Fear/Inhibition, and Constraint versus Impulsivity. This solution overlaps with, but is also distinct from, the major models derived from parent-report measures.
On the relevance of assumptions associated with classical factor analytic approaches.
Kasper, Daniel; Unlü, Ali
2013-01-01
A personal trait, for example a person's cognitive ability, represents a theoretical concept postulated to explain behavior. Interesting constructs are latent, that is, they cannot be observed. Latent variable modeling constitutes a methodology to deal with hypothetical constructs. Constructs are modeled as random variables and become components of a statistical model. As random variables, they possess a probability distribution in the population of reference. In applications, this distribution is typically assumed to be the normal distribution. The normality assumption may be reasonable in many cases, but there are situations where it cannot be justified. For example, this is true for criterion-referenced tests or for background characteristics of students in large scale assessment studies. Nevertheless, the normal procedures in combination with the classical factor analytic methods are frequently pursued, despite the effects of violating this "implicit" assumption are not clear in general. In a simulation study, we investigate whether classical factor analytic approaches can be instrumental in estimating the factorial structure and properties of the population distribution of a latent personal trait from educational test data, when violations of classical assumptions as the aforementioned are present. The results indicate that having a latent non-normal distribution clearly affects the estimation of the distribution of the factor scores and properties thereof. Thus, when the population distribution of a personal trait is assumed to be non-symmetric, we recommend avoiding those factor analytic approaches for estimation of a person's factor score, even though the number of extracted factors and the estimated loading matrix may not be strongly affected. An application to the Progress in International Reading Literacy Study (PIRLS) is given. Comments on possible implications for the Programme for International Student Assessment (PISA) complete the presentation.
Volkan, Kevin; Simon, Steven R.; Baker, Harley; Todres, I. David
2004-01-01
Problem Statement and Background: While the psychometric properties of Objective Structured Clinical Examinations (OSCEs) have been studied, their latent structures have not been well characterized. This study examines a factor analytic model of a comprehensive OSCE and addresses implications for measurement of clinical performance. Methods: An…
Schniering, Carolyn A.; Rapee, Ronald M.
2004-01-01
The aim of this study was to examine the nature and organization of a range of negative self-statements in children and adolescents, using a structural equations/confirmatory factor-analytic approach. A community sample of 978 children aged 7-16 years completed a questionnaire about the frequency with which they experienced a broad range of…
Purcell factor for a cylindrical nanocavity: ab initio analytical approach: reply
DEFF Research Database (Denmark)
Bordo, V.
2014-01-01
The comment by Sun et al. [J. Opt. Soc. Am. B 31, 175 (2014)] on my paper [J. Opt. Soc. Am. B 29, 1799 (2012)] is shown here to be due to a lack of understanding of the approach developed in my papers. (C) 2014 Optical Society of America...
Iwanaga, Kanako; Umucu, Emre; Wu, Jia-Rung; Yaghmaian, Rana; Lee, Hui-Ling; Fitzgerald, Sandra; Chan, Fong
2017-07-04
Self-determination theory (SDT) and self-efficacy theory (SET) can be used to conceptualize self-determined motivation to engage in mental health and vocational rehabilitation (VR) services and to predict recovery. To incorporate SDT and SET as a framework for vocational recovery, developing and validating SDT/SET measures in vocational rehabilitation is warranted. Outcome expectancy is an important SDT/SET variable affecting rehabilitation engagement and recovery. The purpose of this study was to validate the Vocational Outcome Expectancy Scale (VOES) for use within the SDT/SET vocational recovery framework. One hundred and twenty-four individuals with serious mental illness (SMI) participated in this study. Measurement structure of the VOES was evaluated using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Both EFA and CFA results supported a two-factor structure: (a) positive outcome expectancy, and (b) negative outcome expectancy. The internal consistency reliability coefficients for both factors were acceptable. In addition, positive outcome expectancy correlated stronger than negative outcome expectancy with other SDT/SET constructs in the expected directions. The VOES is a brief, reliable and valid instrument for assessing vocational outcome expectancy in individuals with SMI that can be integrated into SDT/SET as a vocational rehabilitation engagement and recovery model in psychiatric rehabilitation.
Lee, Jung Jae; Clarke, Charlotte L
2015-05-01
The aim of this study was to develop and psychometrically test a shortened version of the Information Technology Attitude Scales for Health, in the investigation of nursing students with clinical placement experiences. Nurses and nursing students need to develop high levels of competency in information and communication technology. However, they encounter statistically significant barriers in the use of the technology. Although some instruments have been developed to measure factors that influence nurses' attitudes towards technology, the validity is questionable and few studies have been developed to test the attitudes of nursing students, in particular. A cross-sectional survey design was performed. The Information Technology Attitude Scales for Health was used to collect data from October 2012-December 2012. A panel of experts reviewed the content of the instrument and a pilot study was conducted. Following this, a total of 508 nursing students, who were engaged in clinical placements, were recruited from six universities in South Korea. Exploratory and confirmatory factor analyses were performed and reliability and construct validity were assessed. The resulting instrument consisted of 19 items across four factors. Reliability of the four factors was acceptable and the validity was supported. The instrument was shown to be both valid and reliable for measuring nursing students' attitudes towards technology, thus aiding in the current understandings of this aspect. Through these measurements and understandings, nursing educators and students are able to be more reflexive of their attitudes and can thus seek to develop them positively. © 2015 John Wiley & Sons Ltd.
Shetty, Tushar
2015-01-01
Quality has been identified as an important component for each and every business, irrespective of their size and type, and hence, quality affects each and every activity of an organization crucial for their success. Therefore, since recent times, almost every organization has identified the need of perceiving quality and its management across the supply chain. There are a number of factors affecting the maintenance and management of quality across supply chain. As the topic itself his ...
Lee, J.J.; Clarke, Charlotte
2015-01-01
Aim: The aim of this study was to develop and psychometrically test a shortened version of the Information Technology Attitude Scales for Health, in the investigation of nursing students with clinical placement experiences.Background: Nurses and nursing students need to develop high levels of competency in information and communication technology. However, they encounter significant barriers in the use of the technology. Although some instruments have been developed to measure factors that in...
Analytic Approach to Perturbative QCD
Magradze, B
2000-01-01
The two-loop invariant (running) coupling of QCD is written in terms of the Lambert W function. The analyticity structure of the coupling in the complex Q^2-plane is established. The corresponding analytic coupling is reconstructed via a dispersion relation. We also consider some other approximations to the QCD beta-function, when the corresponding couplings are solved in terms of the Lambert function. The Landau gauge gluon propagator has been considered in the renormalization group invariant analytic approach (IAA). It is shown that there is a nonperturbative ambiguity in determination of the anomalous dimension function of the gluon field. Several analytic solutions for the propagator at the one-loop order are constructed. Properties of the obtained analytical solutions are discussed.
Shenoy Handiru, Vikram; Vinod, A. P.; Guan, Cuntai
2017-08-01
Objective. In electroencephalography (EEG)-based brain-computer interface (BCI) systems for motor control tasks the conventional practice is to decode motor intentions by using scalp EEG. However, scalp EEG only reveals certain limited information about the complex tasks of movement with a higher degree of freedom. Therefore, our objective is to investigate the effectiveness of source-space EEG in extracting relevant features that discriminate arm movement in multiple directions. Approach. We have proposed a novel feature extraction algorithm based on supervised factor analysis that models the data from source-space EEG. To this end, we computed the features from the source dipoles confined to Brodmann areas of interest (BA4a, BA4p and BA6). Further, we embedded class-wise labels of multi-direction (multi-class) source-space EEG to an unsupervised factor analysis to make it into a supervised learning method. Main Results. Our approach provided an average decoding accuracy of 71% for the classification of hand movement in four orthogonal directions, that is significantly higher (>10%) than the classification accuracy obtained using state-of-the-art spatial pattern features in sensor space. Also, the group analysis on the spectral characteristics of source-space EEG indicates that the slow cortical potentials from a set of cortical source dipoles reveal discriminative information regarding the movement parameter, direction. Significance. This study presents evidence that low-frequency components in the source space play an important role in movement kinematics, and thus it may lead to new strategies for BCI-based neurorehabilitation.
Faculty Workload: An Analytical Approach
Dennison, George M.
2012-01-01
Recent discussions of practices in higher education have tended toward muck-raking and self-styled exposure of cynical self-indulgence by faculty and administrators at the expense of students and their families, as usually occurs during periods of economic duress, rather than toward analytical studies designed to foster understanding This article…
Fite, Paula J.; Colder, Craig R.; Pelham, William E., Jr.
2006-01-01
This study used a confirmatory factor model to distinguish pure and co-occurring dimensions of proactive and reactive aggression, and examined the relation between parenting variables and these dimensions of aggression in a sample of 100 children (9 to 12 years of age; 69 boys). Confirmatory factor analysis (CFA) supported 3 dimensions of…
Goldweber, Asha; Bradshaw, Catherine P.; Goodman, Kimberly; Monahan, Kathryn; Cooley-Strickland, Michele
2011-01-01
There is compelling evidence for the role of social information processing (SIP) in aggressive behavior. However, less is known about factors that influence stability versus instability in patterns of SIP over time. Latent transition analysis was used to identify SIP patterns over one year and examine how community violence exposure, aggressive…
An approximate analytical approach to resampling averages
DEFF Research Database (Denmark)
Malzahn, Dorthe; Opper, M.
2004-01-01
Using a novel reformulation, we develop a framework to compute approximate resampling data averages analytically. The method avoids multiple retraining of statistical models on the samples. Our approach uses a combination of the replica "trick" of statistical physics and the TAP approach for appr......Using a novel reformulation, we develop a framework to compute approximate resampling data averages analytically. The method avoids multiple retraining of statistical models on the samples. Our approach uses a combination of the replica "trick" of statistical physics and the TAP approach...
Resilience: A Meta-Analytic Approach
Lee, Ji Hee; Nam, Suk Kyung; Kim, A-Reum; Kim, Boram; Lee, Min Young; Lee, Sang Min
2013-01-01
This study investigated the relationship between psychological resilience and its relevant variables by using a meta-analytic method. The results indicated that the largest effect on resilience was found to stem from the protective factors, a medium effect from risk factors, and the smallest effect from demographic factors. (Contains 4 tables.)
Resilience: A Meta-Analytic Approach
Lee, Ji Hee; Nam, Suk Kyung; Kim, A-Reum; Kim, Boram; Lee, Min Young; Lee, Sang Min
2013-01-01
This study investigated the relationship between psychological resilience and its relevant variables by using a meta-analytic method. The results indicated that the largest effect on resilience was found to stem from the protective factors, a medium effect from risk factors, and the smallest effect from demographic factors. (Contains 4 tables.)
Collaborative Visual Analytics: A Health Analytics Approach to Injury Prevention.
Al-Hajj, Samar; Fisher, Brian; Smith, Jennifer; Pike, Ian
2017-09-12
Background: Accurate understanding of complex health data is critical in order to deal with wicked health problems and make timely decisions. Wicked problems refer to ill-structured and dynamic problems that combine multidimensional elements, which often preclude the conventional problem solving approach. This pilot study introduces visual analytics (VA) methods to multi-stakeholder decision-making sessions about child injury prevention; Methods: Inspired by the Delphi method, we introduced a novel methodology-group analytics (GA). GA was pilot-tested to evaluate the impact of collaborative visual analytics on facilitating problem solving and supporting decision-making. We conducted two GA sessions. Collected data included stakeholders' observations, audio and video recordings, questionnaires, and follow up interviews. The GA sessions were analyzed using the Joint Activity Theory protocol analysis methods; Results: The GA methodology triggered the emergence of 'common ground' among stakeholders. This common ground evolved throughout the sessions to enhance stakeholders' verbal and non-verbal communication, as well as coordination of joint activities and ultimately collaboration on problem solving and decision-making; Conclusions: Understanding complex health data is necessary for informed decisions. Equally important, in this case, is the use of the group analytics methodology to achieve 'common ground' among diverse stakeholders about health data and their implications.
Collaborative Visual Analytics: A Health Analytics Approach to Injury Prevention
Directory of Open Access Journals (Sweden)
Samar Al-Hajj
2017-09-01
Full Text Available Background: Accurate understanding of complex health data is critical in order to deal with wicked health problems and make timely decisions. Wicked problems refer to ill-structured and dynamic problems that combine multidimensional elements, which often preclude the conventional problem solving approach. This pilot study introduces visual analytics (VA methods to multi-stakeholder decision-making sessions about child injury prevention; Methods: Inspired by the Delphi method, we introduced a novel methodology—group analytics (GA. GA was pilot-tested to evaluate the impact of collaborative visual analytics on facilitating problem solving and supporting decision-making. We conducted two GA sessions. Collected data included stakeholders’ observations, audio and video recordings, questionnaires, and follow up interviews. The GA sessions were analyzed using the Joint Activity Theory protocol analysis methods; Results: The GA methodology triggered the emergence of ‘common ground’ among stakeholders. This common ground evolved throughout the sessions to enhance stakeholders’ verbal and non-verbal communication, as well as coordination of joint activities and ultimately collaboration on problem solving and decision-making; Conclusions: Understanding complex health data is necessary for informed decisions. Equally important, in this case, is the use of the group analytics methodology to achieve ‘common ground’ among diverse stakeholders about health data and their implications.
Analytic factorization of Lie group representations
DEFF Research Database (Denmark)
Gimperlein, Heiko; Krötz, Bernhard; Lienau, Christoph
2012-01-01
For every moderate growth representation (p,E)(p,E) of a real Lie group G on a Fréchet space, we prove a factorization theorem of Dixmier–Malliavin type for the space of analytic vectors E¿E¿. There exists a natural algebra of superexponentially decreasing analytic functions A(G)A(G), such that E......¿=¿(A(G))E¿E¿=¿(A(G))E¿. As a corollary we obtain that E¿E¿ coincides with the space of analytic vectors for the Laplace–Beltrami operator on G.......For every moderate growth representation (p,E)(p,E) of a real Lie group G on a Fréchet space, we prove a factorization theorem of Dixmier–Malliavin type for the space of analytic vectors E¿E¿. There exists a natural algebra of superexponentially decreasing analytic functions A(G)A(G), such that E...
Analytical Approaches to Address Homeland Security Issues
Energy Technology Data Exchange (ETDEWEB)
Holter, Gregory M.; Young, Jonathan
2003-11-01
Homeland security concerns arising since September 11, 2001, have captured national attention and sparked a number of responses at all levels of government. As events have unfolded and the nature of the situation has become better understood within the United States, the need for effective planning and response has resulted in the identification of significant analytical challenges. These challenges relate to a number of different needs, including the following: (1) estimating the probability and the potential impact of various threats, (2) identifying the need for and effectiveness of specific counter-measures, and (3) assessing the combined results of interacting activities and events. Analytical approaches traditionally used for safety engineering and risk analysis, coupled with analytical approaches borrowed from other systems analysis disciplines, can be usefully adapted to help meet these challenges. This paper identifies and discusses several illustrative examples of the analytical challenges currently being faced with respect to homeland security. Linkages are then examined between these specific challenges and traditional analytical approaches from a variety of disciplines, including safety engineering and risk analysis. Since effective cooperation among responsible agencies and organizations has been identified as an issue of concern and is essential to achieve an effective homeland security strategy and response capability, issues relating to multiple interacting activities are specifically highlighted.
Emerging pesticide residue issues and analytical approaches.
Fintschenko, Yolanda; Krynitsky, Alexander J; Wong, Jon W
2010-05-26
The 46th Annual Florida Pesticide Residue Workshop of 2009 (FPRW 2009) held in St. Pete Beach, FL, is the latest in an annual tradition drawing scientists from U.S. federal and state government laboratories, industry, and other laboratories worldwide. In 2009, selected FPRW presenters were invited to contribute to this special issue of the Journal of Agricultural and Food Chemistry with a section devoted to emerging pesticide residue issues and analytical approaches. What follows is the written record of what should become a scientific conversation launched at FPRW 2009. There are two distinct approaches to organic residue analysis: instrumental methods and assays. In much of the world, scientists primarily rely on laboratories equipped with instrumentation for analysis, usually gas chromatography and liquid chromatography with some type of selective detector. In the discussion of instrumental approaches, the focus is on chromatography with mass spectrometry as a detection method. Approaches such as biomonitoring and assays fall outside the traditional instrumental method approach to residue analysis. Assays that do not require laboratory equipment are of greater interest for screening and are well-suited to field use. Regardless of the analytical method, the success of multiresidue analysis relies on the appropriate choice of sample preparation and cleanup methodologies. Many new sample preparation and cleanup approaches used for pesticide and other small molecule contaminant residue analyses in a variety of complex sample matrices are discussed in this special issue. The goal of these approaches is to reduce overall analysis time and solvent consumption without compromising the analytical results.
Piecewise deterministic Markov processes : an analytic approach
Alkurdi, Taleb Salameh Odeh
2013-01-01
The subject of this thesis, piecewise deterministic Markov processes, an analytic approach, is on the border between analysis and probability theory. Such processes can either be viewed as random perturbations of deterministic dynamical systems in an impulsive fashion, or as a particular kind of
Age Differences in Personality Structure: A Cluster Analytic Approach
Costa, Paul T., Jr.; McCrae, Robert R.
1976-01-01
Presented at the 81st APA Convention, Montreal, 1973, this study showed how a cluster analytic approach was used to determine age differences in personality measured by the Sixteen Personality Factor Questionnaire (16PF). Subjects were 969 adult male volunteers, 25 to 34, 35 to 54, and 55 to 82. Openness to experience showed age-related…
An analytic approach to cyber adversarial dynamics
Sweeney, Patrick; Cybenko, George
2012-06-01
To date, cyber security investment by both the government and commercial sectors has been largely driven by the myopic best response of players to the actions of their adversaries and their perception of the adversarial environment. However, current work in applying traditional game theory to cyber operations typically assumes that games exist with prescribed moves, strategies, and payos. This paper presents an analytic approach to characterizing the more realistic cyber adversarial metagame that we believe is being played. Examples show that understanding the dynamic metagame provides opportunities to exploit an adversary's anticipated attack strategy. A dynamic version of a graph-based attack-defend game is introduced, and a simulation shows how an optimal strategy can be selected for success in the dynamic environment.
A Functional Analytic Approach to Group Psychotherapy
Vandenberghe, Luc
2009-01-01
This article provides a particular view on the use of Functional Analytical Psychotherapy (FAP) in a group therapy format. This view is based on the author's experiences as a supervisor of Functional Analytical Psychotherapy Groups, including groups for women with depression and groups for chronic pain patients. The contexts in which this approach…
Directory of Open Access Journals (Sweden)
Lee, M. K.
2016-01-01
Full Text Available An absence of measurement bias against distinct groups is a prerequisite for the use of a given psychological instrument in scientific research or high-stakes assessment. Factor analysis is the framework explicitly adopted for the identification of such bias when the instrument consists of a multi-test battery, whereas item response theory is employed when the focus narrows to a single test composed of discrete items. Item response theory can be treated as a mild nonlinearization of the standard factor model, and thus the essential unity of bias detection at the two levels merits greater recognition. Here we illustrate the benefits of a unified approach with a real-data example, which comes from a statewide test of mathematics achievement where examinees diagnosed with dyscalculia were accommodated with calculators. We found that items that can be solved by explicit arithmetical computation became easier for the accommodated examinees, but the quantitative magnitude of this differential item functioning (measurement bias was small.
Learning analytics approach of EMMA project
Tammets, Kairit; Brouns, Francis
2014-01-01
The EMMA project provides a MOOC platform to aggregate and delivers massive open online courses (MOOC) in multiple languages from a variety of European universities. Learning analytics play an important role in MOOCs to support the individual needs of the learner.
Analytic standard errors for exploratory process factor analysis.
Zhang, Guangjian; Browne, Michael W; Ong, Anthony D; Chow, Sy Miin
2014-07-01
Exploratory process factor analysis (EPFA) is a data-driven latent variable model for multivariate time series. This article presents analytic standard errors for EPFA. Unlike standard errors for exploratory factor analysis with independent data, the analytic standard errors for EPFA take into account the time dependency in time series data. In addition, factor rotation is treated as the imposition of equality constraints on model parameters. Properties of the analytic standard errors are demonstrated using empirical and simulated data.
Critical Factors in Data Governance for Learning Analytics
Elouazizi, Noureddine
2014-01-01
This paper identifies some of the main challenges of data governance modelling in the context of learning analytics for higher education institutions, and discusses the critical factors for designing data governance models for learning analytics. It identifies three fundamental common challenges that cut across any learning analytics data…
Analytical evaluation of atomic form factors: application to Rayleigh scattering
Safari, L; Amaro, P; Jänkälä, K; Fratini, F
2014-01-01
Atomic form factors are widely used for the characterization of targets and specimens, from crystallography to biology. By using recent mathematical results, here we derive an analytical expression for the atomic form factor within the independent particle model constructed from nonrelativistic screened hydrogenic wavefunctions. The range of validity of this analytical expression is checked by comparing the analytically obtained form factors with the ones obtained within the Hartee-Fock method. As an example, we apply our analytical expression for the atomic form factor to evaluate the differential cross section for Rayleigh scattering off neutral atoms.
Critical Factors In Data Governance For Learning Analytics
Elouazizi, Noureddine
2014-01-01
This paper identifies some of the main challenges of data governance modeling in the context of learning analytics for higher education institutions, and discusses the critical factors for designing data governance models for learning analytics. It identifies three fundamental common challenges that cut across any learning analytics data governance model, viz., the ownership of the learning analytics data sets, its interpretation and the enacting of decision-making on the basis of this learn...
Transition Studies: Basic Ideas and Analytical Approaches
Grin, J.; Brauch, H.G.; Oswald Spring, Ú.; Grin, J.; Scheffran, J.
2016-01-01
As a background to later contributions, this chapter provides a concise introduction to different approaches to (i) understanding and (ii) shaping transition dynamics: (1) A sociotechnical approach, with the multilevel perspective as its main concept, and strategic niche management as its governance
Spark - a modern approach for distributed analytics
CERN. Geneva; Kothuri, Prasanth
2016-01-01
The Hadoop ecosystem is the leading opensource platform for distributed storing and processing big data. It is a very popular system for implementing data warehouses and data lakes. Spark has also emerged to be one of the leading engines for data analytics. The Hadoop platform is available at CERN as a central service provided by the IT department. By attending the session, a participant will acquire knowledge of the essential concepts need to benefit from the parallel data processing offered by Spark framework. The session is structured around practical examples and tutorials. Main topics: Architecture overview - work distribution, concepts of a worker and a driver Computing concepts of transformations and actions Data processing APIs - RDD, DataFrame, and SparkSQL
A social learning analytics approach to cognitive apprenticeship
National Research Council Canada - National Science Library
Khousa, Eman Abu; Atif, Yacine; Masud, Mohammad M
2015-01-01
.... In this paper, we adopt a data analytics approach combined with contemporary social computing techniques to measure, instil, and track the development of professional competences of learners in higher education...
Morris, Roisin; Scott, Philomena Anne; Cocoman, Angela; Chambers, Mary; Guise, Veslemøy; Välimäki, Maritta; Clinton, Gerard
2012-02-01
This study aimed to assess the construct validity of the Community Attitudes towards the Mentally Ill scale in the investigation of European nurses' attitudes towards mental illness and mental health patients. The harbouring of negative attitudes by nurses towards any patient can have implications for recovery. To gather robust evidence upon which to base information and education aimed at fostering acceptance, support and general positivity towards people with mental health illness, a valid and reliable system of data collection is required. A confirmatory factor analysis of both the original Community Attitudes towards the Mentally Ill scale and two modified versions of the scale were carried out during May - June 2007 using a data set representing the responses of 858 European nurses to the scale. Data were subjected to three different confirmatory factor analyses using Maximum Likelihood estimation in the software package, Analysis of Moment Structures 7. A number of absolute, relative and incremental fit statistics were used to assess the fit of the original Community Attitudes towards the Mentally Ill scale and two modified versions to the European nursing data. A modification of the scale was found to be most suitable for use in the investigation of European nurses' attitudes towards mental illness and people with mental illness. Further research is recommended to develop a valid and reliable research tool to specifically measure the attitudes of 'nurses' working across different mental healthcare facilities towards this vulnerable patient group. © 2011 Blackwell Publishing Ltd.
Identifying Geographic Clusters: A Network Analytic Approach
Catini, Roberto; Penner, Orion; Riccaboni, Massimo
2015-01-01
In recent years there has been a growing interest in the role of networks and clusters in the global economy. Despite being a popular research topic in economics, sociology and urban studies, geographical clustering of human activity has often studied been by means of predetermined geographical units such as administrative divisions and metropolitan areas. This approach is intrinsically time invariant and it does not allow one to differentiate between different activities. Our goal in this paper is to present a new methodology for identifying clusters, that can be applied to different empirical settings. We use a graph approach based on k-shell decomposition to analyze world biomedical research clusters based on PubMed scientific publications. We identify research institutions and locate their activities in geographical clusters. Leading areas of scientific production and their top performing research institutions are consistently identified at different geographic scales.
DEFF Research Database (Denmark)
Zhang, Xiaoxu; Liu, Xiao; Liu, Jinglin;
2015-01-01
Flux-modulated permanent-magnet synchronous machine (FM-PMSM) is characterized as a high-torque direct-drive electrical machine, but may suffer from the low power factor. This paper aims to investigate the issue of the low power factor in theory and explore the possibilities for improvement....... An analytical model for the FM-PMSM is developed to obtain the magnetic field distribution, and its accuracy is verified by the finite-element method. On the basis of the developed analytical model, a fast approach is developed to predict the power factor of the FM-PMSM. The analytical results indicate...
Mackey, Jon; Sehirlioglu, Alp; Dynys, Fred
2014-01-01
A set of convenient thermoelectric device solutions have been derived in order to capture a number of factors which are previously only resolved with numerical techniques. The concise conversion efficiency equations derived from governing equations provide intuitive and straight-forward design guidelines. These guidelines allow for better device design without requiring detailed numerical modeling. The analytical modeling accounts for factors such as i) variable temperature boundary conditions, ii) lateral heat transfer, iii) temperature variable material properties, and iv) transient operation. New dimensionless parameters, similar to the figure of merit, are introduced including the device design factor, fin factor, thermal diffusivity factor, and inductance factor. These new device factors allow for the straight-forward description of phenomenon generally only captured with numerical work otherwise. As an example a device design factor of 0.38, which accounts for thermal resistance of the hot and cold shoes, can be used to calculate a conversion efficiency of 2.28 while the ideal conversion efficiency based on figure of merit alone would be 6.15. Likewise an ideal couple with efficiency of 6.15 will be reduced to 5.33 when lateral heat is accounted for with a fin factor of 1.0.
Discourse-analytic approaches to text and talk
Baxter, Judith A.
2010-01-01
This chapter explores the different ways in which discourse-analytic approaches reveal the ‘meaningfulness’ of text and talk. It reviews four diverse approaches to discourse analysis of particular value for current research in linguistics: Conversation Analysis (CA), Discourse Analysis (DA), Critical Discourse Analysis (CDA) and Feminist Post-structuralist Discourse Analysis (FPDA). Each approach is examined in terms of its background, motivation, key features, and possible strengths and limi...
A new analytic approach to physical observables in QCD
Gaddah, Wajdi
2002-01-01
An analytic ghost-free model for the QCD running coupling $\\alpha(Q^2)$ is proposed. It is constructed from a more general approach we developed particularly for investigating physical observables of the type $F(Q^2)$ in regions that are inaccessible to perturbative methods of quantum field theory. This approach directly links the infrared (IR) and the ultraviolet(UV) regions together under the causal analyticity requirement in the complex $Q^2-$plane. Due to the inclusion of crucial non-pert...
The pion form factor from analyticity and unitarity
Indian Academy of Sciences (India)
B Ananthanarayan; Irinel Caprini; I Sentitemsu Imsong
2012-11-01
Analyticity and unitarity techniques are employed to estimate Taylor coefficients of the pion electromagnetic form factor at = 0 by exploiting the recently evaluated two-pion contribution to the muon ( − 2) and the phase of the pion electromagnetic form factor in the elastic region, known from scattering by Fermi–Watson theorem and the values of the form factor at several points in the space-like region. Regions in the complex -plane are isolated where the form factor cannot have zeros.
A Statistical Mechanics Approach to Approximate Analytical Bootstrap Averages
DEFF Research Database (Denmark)
Malzahn, Dorthe; Opper, Manfred
2003-01-01
We apply the replica method of Statistical Physics combined with a variational method to the approximate analytical computation of bootstrap averages for estimating the generalization error. We demonstrate our approach on regression with Gaussian processes and compare our results with averages...
Principal component and factor analytic models in international sire evaluation
Directory of Open Access Journals (Sweden)
Jakobsen Jette
2011-09-01
Full Text Available Abstract Background Interbull is a non-profit organization that provides internationally comparable breeding values for globalized dairy cattle breeding programmes. Due to different trait definitions and models for genetic evaluation between countries, each biological trait is treated as a different trait in each of the participating countries. This yields a genetic covariance matrix of dimension equal to the number of countries which typically involves high genetic correlations between countries. This gives rise to several problems such as over-parameterized models and increased sampling variances, if genetic (covariance matrices are considered to be unstructured. Methods Principal component (PC and factor analytic (FA models allow highly parsimonious representations of the (covariance matrix compared to the standard multi-trait model and have, therefore, attracted considerable interest for their potential to ease the burden of the estimation process for multiple-trait across country evaluation (MACE. This study evaluated the utility of PC and FA models to estimate variance components and to predict breeding values for MACE for protein yield. This was tested using a dataset comprising Holstein bull evaluations obtained in 2007 from 25 countries. Results In total, 19 principal components or nine factors were needed to explain the genetic variation in the test dataset. Estimates of the genetic parameters under the optimal fit were almost identical for the two approaches. Furthermore, the results were in a good agreement with those obtained from the full rank model and with those provided by Interbull. The estimation time was shortest for models fitting the optimal number of parameters and prolonged when under- or over-parameterized models were applied. Correlations between estimated breeding values (EBV from the PC19 and PC25 were unity. With few exceptions, correlations between EBV obtained using FA and PC approaches under the optimal fit were
Multi-analytical Approaches Informing the Risk of Sepsis
Gwadry-Sridhar, Femida; Lewden, Benoit; Mequanint, Selam; Bauer, Michael
Sepsis is a significant cause of mortality and morbidity and is often associated with increased hospital resource utilization, prolonged intensive care unit (ICU) and hospital stay. The economic burden associated with sepsis is huge. With advances in medicine, there are now aggressive goal oriented treatments that can be used to help these patients. If we were able to predict which patients may be at risk for sepsis we could start treatment early and potentially reduce the risk of mortality and morbidity. Analytic methods currently used in clinical research to determine the risk of a patient developing sepsis may be further enhanced by using multi-modal analytic methods that together could be used to provide greater precision. Researchers commonly use univariate and multivariate regressions to develop predictive models. We hypothesized that such models could be enhanced by using multiple analytic methods that together could be used to provide greater insight. In this paper, we analyze data about patients with and without sepsis using a decision tree approach and a cluster analysis approach. A comparison with a regression approach shows strong similarity among variables identified, though not an exact match. We compare the variables identified by the different approaches and draw conclusions about the respective predictive capabilities,while considering their clinical significance.
Bridging analytical approaches for low-carbon transitions
Geels, Frank W.; Berkhout, Frans; van Vuuren, Detlef P.
2016-06-01
Low-carbon transitions are long-term multi-faceted processes. Although integrated assessment models have many strengths for analysing such transitions, their mathematical representation requires a simplification of the causes, dynamics and scope of such societal transformations. We suggest that integrated assessment model-based analysis should be complemented with insights from socio-technical transition analysis and practice-based action research. We discuss the underlying assumptions, strengths and weaknesses of these three analytical approaches. We argue that full integration of these approaches is not feasible, because of foundational differences in philosophies of science and ontological assumptions. Instead, we suggest that bridging, based on sequential and interactive articulation of different approaches, may generate a more comprehensive and useful chain of assessments to support policy formation and action. We also show how these approaches address knowledge needs of different policymakers (international, national and local), relate to different dimensions of policy processes and speak to different policy-relevant criteria such as cost-effectiveness, socio-political feasibility, social acceptance and legitimacy, and flexibility. A more differentiated set of analytical approaches thus enables a more differentiated approach to climate policy making.
An Analytical Approach to Opportunistic Transmission under Rayleigh Fading Channels
Yousaf Bin Zikria; Sung Won Kim; Heejung Yu; Seung Yeob Nam
2015-01-01
In cognitive radio sensor networks, the routing methods including multiple relays have been extensively studied to achieve higher throughput and lower end-to-end delay. As one of innovative approaches, the opportunistic routing scheme was proposed. In this paper, the effectiveness of the opportunistic transmission in terms of reliability and delay of transmission is verified with an analytical way. For the analysis, we establish the probabilistic model with respect to distance and the number ...
Women's Career Success: A Factor Analytic Study of Contributing Factors.
Gaskill, LuAnn Ricketts
1991-01-01
A survey of 466 women employed in retailing received 205 responses identifying (1) factors influencing the success and advancement of women in retailing and (2) how those factors differ for women in upper versus middle positions. Upper-level executives placed more importance on ambition and abilities; midlevel executives credited opportunity and…
Elements of a function analytic approach to probability.
Energy Technology Data Exchange (ETDEWEB)
Ghanem, Roger Georges (University of Southern California, Los Angeles, CA); Red-Horse, John Robert
2008-02-01
We first provide a detailed motivation for using probability theory as a mathematical context in which to analyze engineering and scientific systems that possess uncertainties. We then present introductory notes on the function analytic approach to probabilistic analysis, emphasizing the connections to various classical deterministic mathematical analysis elements. Lastly, we describe how to use the approach as a means to augment deterministic analysis methods in a particular Hilbert space context, and thus enable a rigorous framework for commingling deterministic and probabilistic analysis tools in an application setting.
Analytical Approaches to Verify Food Integrity: Needs and Challenges.
Stadler, Richard H; Tran, Lien-Anh; Cavin, Christophe; Zbinden, Pascal; Konings, Erik J M
2016-09-01
A brief overview of the main analytical approaches and practices to determine food authenticity is presented, addressing, as well, food supply chain and future requirements to more effectively mitigate food fraud. Food companies are introducing procedures and mechanisms that allow them to identify vulnerabilities in their food supply chain under the umbrella of a food fraud prevention management system. A key step and first line of defense is thorough supply chain mapping and full transparency, assessing the likelihood of fraudsters to penetrate the chain at any point. More vulnerable chains, such as those where ingredients and/or raw materials are purchased through traders or auctions, may require a higher degree of sampling, testing, and surveillance. Access to analytical tools is therefore pivotal, requiring continuous development and possibly sophistication in identifying chemical markers, data acquisition, and modeling. Significant progress in portable technologies is evident already today, for instance, as in the rapid testing now available at the agricultural level. In the near future, consumers may also have the ability to scan products in stores or at home to authenticate labels and food content. For food manufacturers, targeted analytical methods complemented by untargeted approaches are end control measures at the factory gate when the material is delivered. In essence, testing for food adulterants is an integral part of routine QC, ideally tailored to the risks in the individual markets and/or geographies or supply chains. The development of analytical methods is a first step in verifying the compliance and authenticity of food materials. A next, more challenging step is the successful establishment of global consensus reference methods as exemplified by the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals initiative, which can serve as an approach that could also be applied to methods for contaminants and adulterants in food. The food
Big Data Analytics in Immunology: A Knowledge-Based Approach
Directory of Open Access Journals (Sweden)
Guang Lan Zhang
2014-01-01
Full Text Available With the vast amount of immunological data available, immunology research is entering the big data era. These data vary in granularity, quality, and complexity and are stored in various formats, including publications, technical reports, and databases. The challenge is to make the transition from data to actionable knowledge and wisdom and bridge the knowledge gap and application gap. We report a knowledge-based approach based on a framework called KB-builder that facilitates data mining by enabling fast development and deployment of web-accessible immunological data knowledge warehouses. Immunological knowledge discovery relies heavily on both the availability of accurate, up-to-date, and well-organized data and the proper analytics tools. We propose the use of knowledge-based approaches by developing knowledgebases combining well-annotated data with specialized analytical tools and integrating them into analytical workflow. A set of well-defined workflow types with rich summarization and visualization capacity facilitates the transformation from data to critical information and knowledge. By using KB-builder, we enabled streamlining of normally time-consuming processes of database development. The knowledgebases built using KB-builder will speed up rational vaccine design by providing accurate and well-annotated data coupled with tailored computational analysis tools and workflow.
Big data analytics in immunology: a knowledge-based approach.
Zhang, Guang Lan; Sun, Jing; Chitkushev, Lou; Brusic, Vladimir
2014-01-01
With the vast amount of immunological data available, immunology research is entering the big data era. These data vary in granularity, quality, and complexity and are stored in various formats, including publications, technical reports, and databases. The challenge is to make the transition from data to actionable knowledge and wisdom and bridge the knowledge gap and application gap. We report a knowledge-based approach based on a framework called KB-builder that facilitates data mining by enabling fast development and deployment of web-accessible immunological data knowledge warehouses. Immunological knowledge discovery relies heavily on both the availability of accurate, up-to-date, and well-organized data and the proper analytics tools. We propose the use of knowledge-based approaches by developing knowledgebases combining well-annotated data with specialized analytical tools and integrating them into analytical workflow. A set of well-defined workflow types with rich summarization and visualization capacity facilitates the transformation from data to critical information and knowledge. By using KB-builder, we enabled streamlining of normally time-consuming processes of database development. The knowledgebases built using KB-builder will speed up rational vaccine design by providing accurate and well-annotated data coupled with tailored computational analysis tools and workflow.
The behavior-analytic approach to emotional self-control
Directory of Open Access Journals (Sweden)
Jussara Rocha Batista
2012-12-01
Full Text Available Some psychological approaches distinguish behavioral self-control from emotional self-control, the latter being approached with the reference to inside events controlled by the individual himself. This paper offers some directions to a behavior-analytic approach of what has been referred to as emotional self-control. According to Behavior Analysis, no new process is found in emotional self-control, but components that are additional to those found in behavioral self-control, which require appropriate treatment. The paper highlights some determinants of behavioral repertoires taken as instances of emotional self-control: the social context in which self-control is produced and maintained; the conflicts between consequences for the individual and for the group; and the degree of participation of the motor apparatus in the emission of emotional responses. Keywords: emotional self-control; emotional responses; inner world; behavior analysis.
An Analytical Dynamics Approach to the Control of Mechanical Systems
Mylapilli, Harshavardhan
A new and novel approach to the control of nonlinear mechanical systems is presented in this study. The approach is inspired by recent results in analytical dynamics that deal with the theory of constrained motion. The control requirements on the dynamical system are viewed from an analytical dynamics perspective and the theory of constrained motion is used to recast these control requirements as constraints on the dynamical system. Explicit closed form expressions for the generalized nonlinear control forces are obtained by using the fundamental equation of mechanics. The control so obtained is optimal at each instant of time and causes the constraints to be exactly satisfied. No linearizations and/or approximations of the nonlinear dynamical system are made, and no a priori structure is imposed on the nature of nonlinear controller. Three examples dealing with highly nonlinear complex dynamical systems that are chosen from diverse areas of discrete and continuum mechanics are presented to demonstrate the control approach. The first example deals with the energy control of underactuated inhomogeneous nonlinear lattices (or chains), the second example deals with the synchronization of the motion of multiple coupled slave gyros with that of a master gyro, and the final example deals with the control of incompressible hyperelastic rubber-like thin cantilever beams. Numerical simulations accompanying these examples show the ease, simplicity and the efficacy with which the control methodology can be applied and the accuracy with which the desired control objectives can be met.
A New Approach to Spreadsheet Analytics Management in Financial Markets
Sentence, Brian
2008-01-01
Spreadsheets in financial markets are frequently used as database, calculator and reporting application combined. This paper describes an alternative approach in which spreadsheet design and database technology have been brought together in order to alleviate management and regulatory concerns over the operational risks of spreadsheet usage. In particular, the paper focuses on the rapid creation and centralised deployment of statistical analytics within a software system now in use by major investment banks, and presents a novel technique for the manipulation in spreadsheets of high volumes of intraday market data.
Integrated analytical approaches towards toxic algal natural products discovery
DEFF Research Database (Denmark)
Larsen, Thomas Ostenfeld; Rasmussen, Silas Anselm; Gedsted Andersen, Mikael
demonstrated that phenotypic based chemotaxonomy can be successfully used as the intial step in selection of talented strains for testing in various bioassays, using multivariate methods for clustering of whole profiles of metabolites. The second and very important step in the discovery process...... the structures of already known compounds (3). When likely unknown compounds have been identified, we use E-SPE results (4) to predict a fast and optimal purification strategy towards the pure novel compounds for NMR characterization. This presentation will highlight our integrated analytical approaches...
Advances in Assays and Analytical Approaches for Botulinum Toxin Detection
Energy Technology Data Exchange (ETDEWEB)
Grate, Jay W.; Ozanich, Richard M.; Warner, Marvin G.; Bruckner-Lea, Cindy J.; Marks, James D.
2010-08-04
Methods to detect botulinum toxin, the most poisonous substance known, are reviewed. Current assays are being developed with two main objectives in mind: 1) to obtain sufficiently low detection limits to replace the mouse bioassay with an in vitro assay, and 2) to develop rapid assays for screening purposes that are as sensitive as possible while requiring an hour or less to process the sample an obtain the result. This review emphasizes the diverse analytical approaches and devices that have been developed over the last decade, while also briefly reviewing representative older immunoassays to provide background and context.
CMB Anisotropies at Second-Order II: Analytical Approach
Bartolo, N; Riotto, Antonio; Bartolo, Nicola; Matarrese, Sabino; Riotto, Antonio
2007-01-01
We provide an analytical approach to the second-order Cosmic Microwave Background (CMB) anisotropies generated by the non-linear dynamics taking place at last scattering. We study the acoustic oscillations of the photon-baryon fluid in the tight coupling limit and we extend at second-order the Meszaros effect.We allow for a generic set of initial conditions due to primordial non-Gaussianity and we compute all the additional contributions arising at recombination. Our results are useful to provide the full second-order radiation transfer function at all scales necessary for establishing the level of non-Gaussianity in the CMB.
Impact of Analytics in Financial Decision Making: Evidence from a Case Study Approach
Directory of Open Access Journals (Sweden)
Durrel Ramrathan
2014-10-01
Full Text Available This study seeks to investigate the impact of analytics in financial decision making in organizations in a rapidly growing knowledge economy. Analytics has emerged as a critical business enabler in today‟s competitive market place. Its application has provided businesses with the opportunity to gain a competitive advantage by leveraging the vast amount of data they have available. Analytics is not limited to a particular tool or method however; it encompasses a range of combinations and it is this element that has made analytics such a success factor. This study uses a case study approach to identify critical areas of business where analytics have played a vital role in financial decision making. Application of analytics in financial decision making is shown to streamline information resulting in making decisions more efficiently and effectively. This study provides insights in financial decision making using statistical backing which has a vast number of applications in finance functions. As such, areas such as such detecting fraud, budgeting and forecasting, risk management and customer insights need to actively apply analytical tools to better manage and enhance the information gained from these areas. This study integrates the use of information technology tools and packages with financial management with the view of enhancing financial decision flow in organizations.
Analytic phase-factor equations for Talbot array illuminations.
Zhou, C; Stankovic, S; Tschudi, T
1999-01-10
Under specific circumstances the fractional Talbot effect can be described by simplified equations. We have obtained simplified analytic phase-factor equations to describe the relation between the pure-phase factors and their fractional Talbot distances behind a binary amplitude grating with an opening ratio of (1/M). We explain how these simple equations are obtained from the regularly rearranged neighboring phase differences. We point out that any intensity distribution with an irreducible opening ratio (M(N)/M) (M(N) illumination in this case. Experimental verification of our theoretical results is given.
ANALYTICAL APPROACHES TO THE STUDY OF EXPORT TRANSACTIONS
Directory of Open Access Journals (Sweden)
Ekaterina Viktorovna Medvedeva
2015-12-01
Full Text Available Analytical approaches to research of export operations depend on the conditions containing in separate external economic contracts with foreign buyers and also on a form of an exit of the Russian supplier of export goods to a foreign market. By means of analytical procedures it is possible to foresee and predict admissible situations which can have an adverse effect on a financial position of the economic subject. The economic entity, the engaged foreign economic activity, has to carry out surely not only the analysis of the current activity, but also the analysis of export operations. In article analytical approaches of carrying out the analysis of export operations are considered, on an example the analysis of export operations in dynamics is submitted, it is recommended to use the formulas allowing to estimate export in dynamics. For the comparative analysis export volume in the comparable prices is estimated. On the commodity groups including and quantitatively and qualitatively commensurable goods, the index of quantitative structure is calculated, the coefficient of delay of delivery of goods in comparison with other periods pays off. Carrying out the analysis allows to determine a tendency of change of export deliveries by export operations for the analyzed period for adoption of administrative decisions.Purpose Definition of the ways and receptions of the analysis applying when carrying out the analysis of export operations.Methodology in article economic-mathematical methods, and also statistical methods of the analysis were used.Results: the most informative parameters showing some aspects of carrying out the analysis of export operations are received.Practical implications it is expedient to apply the received results the economic subjects which are carrying out foreign economic activity, one of which elements are export operations.
Cognitive neuroscience robotics B analytic approaches to human understanding
Ishiguro, Hiroshi; Asada, Minoru; Osaka, Mariko; Fujikado, Takashi
2016-01-01
Cognitive Neuroscience Robotics is the first introductory book on this new interdisciplinary area. This book consists of two volumes, the first of which, Synthetic Approaches to Human Understanding, advances human understanding from a robotics or engineering point of view. The second, Analytic Approaches to Human Understanding, addresses related subjects in cognitive science and neuroscience. These two volumes are intended to complement each other in order to more comprehensively investigate human cognitive functions, to develop human-friendly information and robot technology (IRT) systems, and to understand what kind of beings we humans are. Volume B describes to what extent cognitive science and neuroscience have revealed the underlying mechanism of human cognition, and investigates how development of neural engineering and advances in other disciplines could lead to deep understanding of human cognition.
The Navier-Stokes equations an elementary functional analytic approach
Sohr, Hermann
2001-01-01
The primary objective of this monograph is to develop an elementary and self-contained approach to the mathematical theory of a viscous, incompressible fluid in a domain of the Euclidean space, described by the equations of Navier-Stokes. Moreover, the theory is presented for completely general domains, in particular, for arbitrary unbounded, nonsmooth domains. Therefore, restriction was necessary to space dimensions two and three, which are also the most significant from a physical point of view. For mathematical generality, however, the linearized theory is expounded for general dimensions higher than one. Although the functional analytic approach developed here is, in principle, known to specialists, the present book fills a gap in the literature providing a systematic treatment of a subject that has been documented until now only in fragments. The book is mainly directed to students familiar with basic tools in Hilbert and Banach spaces. However, for the readers’ convenience, some fundamental properties...
The Navier-Stokes equations an elementary functional analytic approach
Sohr, Hermann
2001-01-01
The primary objective of this monograph is to develop an elementary and self contained approach to the mathematical theory of a viscous incompressible fluid in a domain 0 of the Euclidean space ]Rn, described by the equations of Navier Stokes. The book is mainly directed to students familiar with basic functional analytic tools in Hilbert and Banach spaces. However, for readers' convenience, in the first two chapters we collect without proof some fundamental properties of Sobolev spaces, distributions, operators, etc. Another important objective is to formulate the theory for a completely general domain O. In particular, the theory applies to arbitrary unbounded, non-smooth domains. For this reason, in the nonlinear case, we have to restrict ourselves to space dimensions n = 2,3 that are also most significant from the physical point of view. For mathematical generality, we will develop the lin earized theory for all n 2 2. Although the functional-analytic approach developed here is, in principle, known ...
Factor analytic study of the personality of female methadone outpatients.
Duthie, R B
1980-10-01
Several researchers have examined the personality of chemical abusers by employing a multivariate clustering strategy. All of these studies focused on hospitalized inpatient addicts. Only one included females in the study. The purpose of this study is to examine the transposed data factor analytically derived profiles of female methadone maintained outpatients. All clients were given the Mini-Mult short form version of the Minnesota Multiphasic Personality Inventory. Seventy profiles were randomly selected from 130 female profiles. Program Factor of the Analyses of Behavioral Sciences Data program series was employed in statistically processing this data. Descriptions of the five factors are provided. Most of the profile types seem to fall into the normal or personality disordered categories. Forth-two percent of the profiles were normal, 24% were Personality Disorders, 6% were Neurotic, and 28% were unclassified using five factors.
Taming Landau singularities in QCD perturbation theory: The analytic approach
Stefanis, N G
2013-01-01
The aim of this topical article is to outline the fundamental ideas underlying the recently developed Fractional Analytic Perturbation Theory (FAPT) of QCD and present its main calculational tools. For this, it is first necessary to review previous methods to apply QCD perturbation theory at low spacelike momentum scales, where the influence of the Landau singularities becomes inevitable. Several concepts are considered and their limitations are pointed out. The usefulness of FAPT is discussed in terms of two characteristic hadronic quantities: the perturbatively calculable part of the pion's electromagnetic form factor in the spacelike region and the Higgs-boson decay into a b\\bar b pair in the timelike region. In the first case, the focus is on the optimization of the prediction with respect to the choice of the renormalization scheme and the dependence on the renormalization and the factorization scales. The second case serves to show that the application of FAPT to this reaction reaches already at the fou...
Manna, Venessa F.; Yoo, Hanwook
2015-01-01
This study examined the heterogeneity in the English-as-a-second-language (ESL) test population by modeling the relationship between test-taker background characteristics and test performance as measured by the "TOEFL iBT"® using a confirmatory factor analysis (CFA) with covariate approach. The background characteristics studied…
Methods for estimating uncertainty in factor analytic solutions
Directory of Open Access Journals (Sweden)
P. Paatero
2013-08-01
Full Text Available EPA PMF version 5.0 and the underlying multilinear engine executable ME-2 contain three methods for estimating uncertainty in factor analytic models: classical bootstrap (BS, displacement of factor elements (DISP, and bootstrap enhanced by displacement of factor elements (BS-DISP. The goal of these methods is to capture the uncertainty of PMF analyses due to random errors and rotational ambiguity. It is shown that the three methods complement each other: depending on characteristics of the data set, one method may provide better results than the other two. Results are presented using synthetic data sets, including interpretation of diagnostics, and recommendations are given for parameters to report when documenting uncertainty estimates from EPA PMF or ME-2 applications.
Transcription factor-based biosensors enlightened by the analyte.
Directory of Open Access Journals (Sweden)
Raul eFernandez-Lopez
2015-07-01
Full Text Available Whole cell biosensors (WCBs have multiple applications for environmental monitoring, detecting a wide range of pollutants. WCBs depend critically on the sensitivity and specificity of the transcription factor (TF used to detect the analyte. We describe the mechanism of regulation and the structural and biochemical properties of TF families that are used, or could be used, for the development of environmental WCBs. Focusing on the chemical nature of the analyte, we review TFs that respond to aromatic compounds (XylS-AraC, XylR-NtrC and LysR, metal ions (MerR, ArsR, DtxR, Fur and NikR or antibiotics (TetR and MarR. Analyzing the structural domains involved in DNA recognition, we highlight the similitudes in the DNA binding domains (DBDs of these TF families. Opposite to DBDs, the wide range of analytes detected by TFs results in a diversity of structures at the effector binding domain (EBD. The modular architecture of TFs opens the possibility of engineering TFs with hybrid DNA and effector specificities. Yet, the lack of a crisp correlation between structural domains and specific functions makes this a challenging task.
Analytical and Numerical Approaches to Modelling of Reinforcement Corrosion in Concrete
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Vořechovská Dita
2014-06-01
Full Text Available Corrosion of reinforcement in concrete is one of the most influencing factors causing the degradation of RC structures. This paper attempts at the application of an analytical and numerical approaches to simulation of concrete cracking due to reinforcement corrosion. At first, a combination with detailed analysis of two analytical models proposed by Liu and Weyers (1998 and Li et al. (2006 is suggested and presented. Four distinct phases of the corrosion process are identified and a detailed guide through the mathematical development is described. Next, numerical computations obtained with nonlinear finite element code are presented. The model features the state-of-the-art in nonlinear fracture mechanics modelling and the heterogeneous structure of concrete is modelled via spatially varying parameters of the constitutive law. Finally, the results of the analytical studies are compared to numerical computations and the paper concludes with the sketch of a real-life numerical example.
A Visual Analytics Approach for Correlation, Classification, and Regression Analysis
Energy Technology Data Exchange (ETDEWEB)
Steed, Chad A [ORNL; SwanII, J. Edward [Mississippi State University (MSU); Fitzpatrick, Patrick J. [Mississippi State University (MSU); Jankun-Kelly, T.J. [Mississippi State University (MSU)
2012-02-01
New approaches that combine the strengths of humans and machines are necessary to equip analysts with the proper tools for exploring today's increasing complex, multivariate data sets. In this paper, a novel visual data mining framework, called the Multidimensional Data eXplorer (MDX), is described that addresses the challenges of today's data by combining automated statistical analytics with a highly interactive parallel coordinates based canvas. In addition to several intuitive interaction capabilities, this framework offers a rich set of graphical statistical indicators, interactive regression analysis, visual correlation mining, automated axis arrangements and filtering, and data classification techniques. The current work provides a detailed description of the system as well as a discussion of key design aspects and critical feedback from domain experts.
Haze of surface random systems: An approximate analytic approach
Simonsen, Ingve; Andreassen, Erik; Ommundsen, Espen; Nord-Varhaug, Katrin
2009-01-01
Approximate analytic expressions for haze (and gloss) of Gaussian randomly rough surfaces for various types of correlation functions are derived within phase-perturbation theory. The approximations depend on the angle of incidence, polarization of the incident light, the surface roughness, $\\sigma$, and the average of the power spectrum taken over a small angular interval about the specular direction. In particular it is demonstrated that haze(gloss) increase(decrease) with $\\sigma/\\lambda$ as $\\exp(-A(\\sigma/\\lambda)^2)$ and decreases(increase) with $a/\\lambda$, where $a$ is the correlation length of the surface roughness, in a way that depends on the specific form of the correlation function being considered. These approximations are compared to what can be obtained from a rigorous Monte Carlo simulation approach, and good agreement is found over large regions of parameter space. Some experimental results for the angular distribution of the transmitted light through polymer films, and their haze, are presen...
Ohmic Inflation of Hot Jupiters: an Analytical Approach
Ginzburg, Sivan; Sari, Re'em
2015-12-01
Many giant exoplanets in close orbits have observed radii which exceed theoretical predictions.One suggested explanation for this discrepancy is heat deposited deep inside the atmospheres of these hot Jupiters.We present an analytical model for the evolution of such irradiated, and internally heated gas giants, and derive scaling laws for their cooling rates and radii.We estimate the Ohmic dissipation resulting from the interaction between the atmospheric winds and the planet's magnetic field, and apply our model to Ohmically heated planets.Our model can account for the observed radii of many inflated planets, but not the most extreme ones.We show that Ohmically heated planets have already reached their equilibrium phase and they no longer contract.We show that it is possible to re-inflate planets, but we confirm that re-heating timescales are longer by about a factor of 30 than cooling times.
Gamage, K A A; Joyce, M J
2011-10-01
A novel analytical approach is described that accounts for self-shielding of γ radiation in decommissioning scenarios. The approach is developed with plutonium-239, cobalt-60 and caesium-137 as examples; stainless steel and concrete have been chosen as the media for cobalt-60 and caesium-137, respectively. The analytical methods have been compared MCNPX 2.6.0 simulations. A simple, linear correction factor relates the analytical results and the simulated estimates. This has the potential to greatly simplify the estimation of self-shielding effects in decommissioning activities.
Analytic two-loop form factors in N=4 SYM
Brandhuber, Andreas; Yang, Gang
2012-01-01
We derive a compact expression for the three-point MHV form factors of half-BPS operators in N=4super Yang-Mills at two loops. The main tools of our calculation are generalised unitarity applied at the form factor level, and the compact expressions for supersymmetric tree-level form factors and amplitudes entering the cuts. We confirm that infrared divergences exponentiate as expected, and that collinear factorisation is entirely captured by an ABDK/BDS ansatz. Next, we construct the two-loop remainder function obtained by subtracting this ansatz from the full two-loop form factor and compute it numerically. Using symbology, combined with various physical constraints and symmetries, we find a unique solution for its symbol. With this input we construct a remarkably compact analytic expression for the remainder function, which contains only classical polylogarithms, and compare it to our numerical results. Furthermore, we make the surprising observation that our remainder is equal to the maximally transcendent...
Clarivate Analytics: Continued Omnia vanitas Impact Factor Culture.
Teixeira da Silva, Jaime A; Bernès, Sylvain
2017-02-23
This opinion paper takes aim at an error made recently by Clarivate Analytics in which it sent out an email that congratulated academics for becoming exclusive members of academia's most cited elite, the Highly Cited Researchers (HCRs). However, that email was sent out to an undisclosed number of non-HCRs, who were offered an apology shortly after, through a bulk mail, which tried to down-play the importance of the error, all the while praising the true HCRs. When Clarivate Analytics senior management was contacted, the company declined to offer an indication of the number of academics who had been contacted and erroneously awarded the HCR status. We believe that this regrettable blunder, together with the opacity offered by the company, fortify the corporate attitude about the value of the journal impact factor (JIF), and what it represents, namely a marketing tool that is falsely used to equate citations with quality, worth, or influence. The continued commercialization of metrics such as the JIF is at the heart of their use to assess the "quality" of a researcher, their work, or a journal, and contributes to a great extent to driving scientific activities towards a futile endeavor.
BOOK REVIEW Analytical and Numerical Approaches to Mathematical Relativity
Stewart, John M.
2007-08-01
The 319th Wilhelm-and-Else-Heraeus Seminar 'Mathematical Relativity: New Ideas and Developments' took place in March 2004. Twelve of the invited speakers have expanded their one hour talks into the papers appearing in this volume, preceded by a foreword by Roger Penrose. The first group consists of four papers on 'differential geometry and differential topology'. Paul Ehrlich opens with a very witty review of global Lorentzian geometry, which caused this reviewer to think more carefully about how he uses the adjective 'generic'. Robert Low addresses the issue of causality with a description of the 'space of null geodesics' and a tentative proposal for a new definition of causal boundary. The underlying review of global Lorentzian geometry is continued by Antonio Masiello, looking at variational approaches (actually valid for more general semi-Riemannian manifolds). This group concludes with a very clear review of pp-wave spacetimes from José Flores and Miguel Sánchez. (This reviewer was delighted to see a reproduction of Roger Penrose's seminal (1965) picture of null geodesics in plane wave spacetimes which attracted him into the subject.) Robert Beig opens the second group 'analytic methods and differential equations' with a brief but careful discussion of symmetric (regular) hyperbolicity for first (second) order systems, respectively, of partial differential equations. His description is peppered with examples, many specific to relativstic continuum mechanics. There follows a succinct review of linear elliptic boundary value problems with applications to general relativity from Sergio Dain. The numerous examples he provides are thought-provoking. The 'standard cosmological model' has been well understood for three quarters of a century. However recent observations suggest that the expansion in our Universe may be accelerating. Alan Rendall provides a careful discussion of the changes, both mathematical and physical, to the standard model which might be needed
Consistent analytic approach to the efficiency of collisional Penrose process
Harada, Tomohiro; Miyamoto, Umpei
2016-01-01
We propose a consistent analytic approach to the efficiency of collisional Penrose process in the vicinity of a maximally rotating Kerr black hole. We focus on a collision with arbitrarily high centre-of-mass energy, which occurs if either of the colliding particles has its angular momentum finetuned to the critical value to enter the horizon. We show that if the finetuned particle is ingoing on the collision, the upper limit of the efficiency is $(2+\\sqrt{3})(2-\\sqrt{2})\\simeq 2.186$, while if the finetuned particle is bounced back before the collision, the upper limit is $(2+\\sqrt{3})^{2}\\simeq 13.93$. Despite earlier claims, the former can be attained for inverse Compton scattering if the finetuned particle is massive and starts at rest at infinity, while the latter for various particle reactions, such as inverse Compton scattering and pair annihilation, if the finetuned particle is either massless or highly relativistic at infinity. We discuss difference between the present and earlier analyses.
A decision analytic approach to exposure-based chemical prioritization.
Directory of Open Access Journals (Sweden)
Jade Mitchell
Full Text Available The manufacture of novel synthetic chemicals has increased in volume and variety, but often the environmental and health risks are not fully understood in terms of toxicity and, in particular, exposure. While efforts to assess risks have generally been effective when sufficient data are available, the hazard and exposure data necessary to assess risks adequately are unavailable for the vast majority of chemicals in commerce. The US Environmental Protection Agency has initiated the ExpoCast Program to develop tools for rapid chemical evaluation based on potential for exposure. In this context, a model is presented in which chemicals are evaluated based on inherent chemical properties and behaviorally-based usage characteristics over the chemical's life cycle. These criteria are assessed and integrated within a decision analytic framework, facilitating rapid assessment and prioritization for future targeted testing and systems modeling. A case study outlines the prioritization process using 51 chemicals. The results show a preliminary relative ranking of chemicals based on exposure potential. The strength of this approach is the ability to integrate relevant statistical and mechanistic data with expert judgment, allowing for an initial tier assessment that can further inform targeted testing and risk management strategies.
Analytical approach for resolving stress states around elliptical cavities
Directory of Open Access Journals (Sweden)
Lukić Dragan
2005-01-01
Full Text Available The determination of stress states around cavities in the stressed elastic body, regardless of cavity shapes, that may be spherical, cylindrical elliptical etc. in its analytical approach has to be based on selection of a stress function that will satisfy biharmonic equation, under given boundary conditions. This paper is concerned with formulation and solution of the cited differential equation using elliptical coordinates in conformity with the cavity shape of oblong ellipsoid [1]. It is therefore considered that the formulation of the stress tensor will be done in conformity to the cited coordinates. The paper describes basic statements and definitions in connection to harmonic functions used for determination of stress states around cavities formed in the stressed homogeneous space. The particular attention has been paid to the use of Legendre`s functions, with definitions and derivation of recurrent formulas, that have been used for determination of stress states around an oblong ellipsoidal cavity, [1]. The paper also includes the description of procedures used in forming series based on Legendre`s functions of the first order.
Linear response theory an analytic-algebraic approach
De Nittis, Giuseppe
2017-01-01
This book presents a modern and systematic approach to Linear Response Theory (LRT) by combining analytic and algebraic ideas. LRT is a tool to study systems that are driven out of equilibrium by external perturbations. In particular the reader is provided with a new and robust tool to implement LRT for a wide array of systems. The proposed formalism in fact applies to periodic and random systems in the discrete and the continuum. After a short introduction describing the structure of the book, its aim and motivation, the basic elements of the theory are presented in chapter 2. The mathematical framework of the theory is outlined in chapters 3–5: the relevant von Neumann algebras, noncommutative $L^p$- and Sobolev spaces are introduced; their construction is then made explicit for common physical systems; the notion of isopectral perturbations and the associated dynamics are studied. Chapter 6 is dedicated to the main results, proofs of the Kubo and Kubo-Streda formulas. The book closes with a chapter about...
Consistent analytic approach to the efficiency of collisional Penrose process
Harada, Tomohiro; Ogasawara, Kota; Miyamoto, Umpei
2016-07-01
We propose a consistent analytic approach to the efficiency of collisional Penrose process in the vicinity of a maximally rotating Kerr black hole. We focus on a collision with arbitrarily high center-of-mass energy, which occurs if either of the colliding particles has its angular momentum fine-tuned to the critical value to enter the horizon. We show that if the fine-tuned particle is ingoing on the collision, the upper limit of the efficiency is (2 +√{3 })(2 -√{2 })≃2.186 , while if the fine-tuned particle is bounced back before the collision, the upper limit is (2 +√{3 })2≃13.93 . Despite earlier claims, the former can be attained for inverse Compton scattering if the fine-tuned particle is massive and starts at rest at infinity, while the latter can be attained for various particle reactions, such as inverse Compton scattering and pair annihilation, if the fine-tuned particle is either massless or highly relativistic at infinity. We discuss the difference between the present and earlier analyses.
Directory of Open Access Journals (Sweden)
Larissa B. Del Piero
2016-06-01
Full Text Available Early neuroimaging studies suggested that adolescents show initial development in brain regions linked with emotional reactivity, but slower development in brain structures linked with emotion regulation. However, the increased sophistication of adolescent brain research has made this picture more complex. This review examines functional neuroimaging studies that test for differences in basic emotion processing (reactivity and regulation between adolescents and either children or adults. We delineated different emotional processing demands across the experimental paradigms in the reviewed studies to synthesize the diverse results. The methods for assessing change (i.e., analytical approach and cohort characteristics (e.g., age range were also explored as potential factors influencing study results. Few unifying dimensions were found to successfully distill the results of the reviewed studies. However, this review highlights the potential impact of subtle methodological and analytic differences between studies, need for standardized and theory-driven experimental paradigms, and necessity of analytic approaches that are can adequately test the trajectories of developmental change that have recently been proposed. Recommendations for future research highlight connectivity analyses and non-linear developmental trajectories, which appear to be promising approaches for measuring change across adolescence. Recommendations are made for evaluating gender and biological markers of development beyond chronological age.
Learning Analytics for Online Discussions: Embedded and Extracted Approaches
Wise, Alyssa Friend; Zhao, Yuting; Hausknecht, Simone Nicole
2014-01-01
This paper describes an application of learning analytics that builds on an existing research program investigating how students contribute and attend to the messages of others in asynchronous online discussions. We first overview the E-Listening research program and then explain how this work was translated into analytics that students and…
Bayesian Constrained-Model Selection for Factor Analytic Modeling
Peeters, Carel F.W.
2016-01-01
My dissertation revolves around Bayesian approaches towards constrained statistical inference in the factor analysis (FA) model. Two interconnected types of restricted-model selection are considered. These types have a natural connection to selection problems in the exploratory FA (EFA) and confirmatory FA (CFA) model and are termed Type I and Type II model selection. Type I constrained-model selection is taken to mean the determination of the appropriate dimensionality of a model. This type ...
Geovisual Analytics Approach to Exploring Public Political Discourse on Twitter
Directory of Open Access Journals (Sweden)
Jonathan K. Nelson
2015-03-01
Full Text Available We introduce spatial patterns of Tweets visualization (SPoTvis, a web-based geovisual analytics tool for exploring messages on Twitter (or “tweets” collected about political discourse, and illustrate the potential of the approach with a case study focused on a set of linked political events in the United States. In October 2013, the U.S. Congressional debate over the allocation of funds to the Patient Protection and Affordable Care Act (commonly known as the ACA or “Obamacare” culminated in a 16-day government shutdown. Meanwhile the online health insurance marketplace related to the ACA was making a public debut hampered by performance and functionality problems. Messages on Twitter during this time period included sharply divided opinions about these events, with many people angry about the shutdown and others supporting the delay of the ACA implementation. SPoTvis supports the analysis of these events using an interactive map connected dynamically to a term polarity plot; through the SPoTvis interface, users can compare the dominant subthemes of Tweets in any two states or congressional districts. Demographic attributes and political information on the display, coupled with functionality to show (dissimilar features, enrich users’ understandings of the units being compared. Relationships among places, politics and discourse on Twitter are quantified using statistical analyses and explored visually using SPoTvis. A two-part user study evaluates SPoTvis’ ability to enable insight discovery, as well as the tool’s design, functionality and applicability to other contexts.
Worley, Jody A.; Vassar, Matt; Wheeler, Denna L.; Barnes, Laura L. B.
2008-01-01
This study provides a summary of 45 exploratory and confirmatory factor-analytic studies that examined the internal structure of scores obtained from the Maslach Burnout Inventory (MBI). It highlights characteristics of the studies that account for differences in reporting of the MBI factor structure. This approach includes an examination of the…
Cartesian stiffness matrix of manipulators with passive joints: analytical approach
Pashkevich, Anatoly; Caro, Stéphane; Chablat, Damien
2011-01-01
The paper focuses on stiffness matrix computation for manipulators with passive joints. It proposes both explicit analytical expressions and an efficient recursive procedure that are applicable in general case and allow obtaining the desired matrix either in analytical or numerical form. Advantages of the developed technique and its ability to produce both singular and non-singular stiffness matrices are illustrated by application examples that deal with stiffness modeling of two Stewart-Gough platforms.
Analytical quality-by-design approach for sample treatment of BSA-containing solutions
Institute of Scientific and Technical Information of China (English)
Lien Taevernier; Evelien Wynendaele; Matthias D’Hondt; Bart De Spiegeleer
2015-01-01
The sample preparation of samples containing bovine serum albumin (BSA), e.g., as used in transdermal Franz diffusion cell (FDC) solutions, was evaluated using an analytical quality-by-design (QbD) approach. Traditional precipitation of BSA by adding an equal volume of organic solvent, often successfully used with conventional HPLC-PDA, was found insufficiently robust when novel fused-core HPLC and/or UPLC-MS methods were used. In this study, three factors (acetonitrile (%), formic acid (%) and boiling time (min)) were included in the experimental design to determine an optimal and more suitable sample treatment of BSA-containing FDC solutions. Using a QbD and Derringer desirability (D) approach, combining BSA loss, dilution factor and variability, we constructed an optimal working space with the edge of failure defined as Do0.9. The design space is modelled and is confirmed to have an ACN range of 8373%and FA content of 170.25%.
Examining roles pharmacists assume in disasters: a content analytic approach.
Ford, Heath; Dallas, Cham E; Harris, Curt
2013-12-01
Numerous practice reports recommend roles pharmacists may adopt during disasters. This study examines the peer-reviewed literature for factors that explain the roles pharmacists assume in disasters and the differences in roles and disasters when stratified by time. Quantitative content analysis was used to gather data consisting of words and phrases from peer-reviewed pharmacy literature regarding pharmacists' roles in disasters. Negative binomial regression and Kruskal-Wallis nonparametric models were applied to the data. Pharmacists' roles in disasters have not changed significantly since the 1960s. Pharmaceutical supply remains their preferred role, while patient management and response integration roles decrease in context of common, geographically widespread disasters. Policy coordination roles, however, significantly increase in nuclear terrorism planning. Pharmacists' adoption of nonpharmaceutical supply roles may represent a problem of accepting a paradigm shift in nontraditional roles. Possible shortages of personnel in future disasters may change the pharmacists' approach to disaster management.
Relative frequencies of constrained events in stochastic processes: An analytical approach
Rusconi, S.; Akhmatskaya, E.; Sokolovski, D.; Ballard, N.; de la Cal, J. C.
2015-10-01
The stochastic simulation algorithm (SSA) and the corresponding Monte Carlo (MC) method are among the most common approaches for studying stochastic processes. They relies on knowledge of interevent probability density functions (PDFs) and on information about dependencies between all possible events. Analytical representations of a PDF are difficult to specify in advance, in many real life applications. Knowing the shapes of PDFs, and using experimental data, different optimization schemes can be applied in order to evaluate probability density functions and, therefore, the properties of the studied system. Such methods, however, are computationally demanding, and often not feasible. We show that, in the case where experimentally accessed properties are directly related to the frequencies of events involved, it may be possible to replace the heavy Monte Carlo core of optimization schemes with an analytical solution. Such a replacement not only provides a more accurate estimation of the properties of the process, but also reduces the simulation time by a factor of order of the sample size (at least ≈104 ). The proposed analytical approach is valid for any choice of PDF. The accuracy, computational efficiency, and advantages of the method over MC procedures are demonstrated in the exactly solvable case and in the evaluation of branching fractions in controlled radical polymerization (CRP) of acrylic monomers. This polymerization can be modeled by a constrained stochastic process. Constrained systems are quite common, and this makes the method useful for various applications.
Analytical approach to quasiperiodic beam Coulomb field modeling
Rubtsova, I. D.
2016-09-01
The paper is devoted to modeling of space charge field of quasiperiodic axial- symmetric beam. Particle beam is simulated by charged disks. Two analytical Coulomb field expressions are presented, namely, Fourier-Bessel series and trigonometric polynomial. Both expressions permit the integral representation. It provides the possibility of integro-differential beam dynamics description. Consequently, when beam dynamics optimization problem is considered, it is possible to derive the analytical formula for quality functional gradient and to apply directed optimization methods. In addition, the paper presents the method of testing of space charge simulation code.
Scaling trends in energy recovery logic: an analytical approach
Institute of Scientific and Technical Information of China (English)
Jitendra Kanungo; S.Dasgupta
2013-01-01
This paper presents an analytical model to study the scaling trends in energy recovery logic.The energy performance of conventional CMOS and energy recovery logic are compared with scaling the design and technology parameters such as supply voltage,device threshold voltage and gate oxide thickness.The proposed analytical model is validated with simulation results at 90 nm and 65 nm CMOS technology nodes and predicts the scaling behavior accurately that help us to design an energy-efficient CMOS digital circuit design at the nanoscale.This research work shows the adiabatic switching as an ultra-low-power circuit technique for sub-100 nm digital CMOS circuit applications.
Optical properties of a two-nanospheroid cluster: analytical approach
Guzatov, D V
2010-01-01
Optical properties of a plasmonic nano-antenna made of two metallic nanospheroids (prolate or oblate) are investigated analytically in quasistatic approximation. It is shown that in clusters of two nanospheroids, three types of plasmonic modes can be present. Two of them can be effectively excited by a plane electromagnetic wave, while the third one can be effectively excited only by a nanolocalized light source (an atom, a molecule, a quantum dot) placed in the gap between the nanoparticles. Analytical expressions for absorption and scattering cross-sections, enhancement of a local field, and radiative decay rate of a dipole source placed near such a nano-antenna are presented and analyzed.
Saengprom, Narumon; Erawan, Waraporn; Damrongpanit, Suntonrapot; Sakulku, Jaruwan
2015-01-01
The purposes of this study were 1) Compare analytical thinking ability by testing the same sets of students 5 times 2) Develop and verify whether analytical thinking ability of students corresponds to second-order growth curve factors model. Samples were 1,093 eighth-grade students. The results revealed that 1) Analytical thinking ability scores…
Saengprom, Narumon; Erawan, Waraporn; Damrongpanit, Suntonrapot; Sakulku, Jaruwan
2015-01-01
The purposes of this study were 1) Compare analytical thinking ability by testing the same sets of students 5 times 2) Develop and verify whether analytical thinking ability of students corresponds to second-order growth curve factors model. Samples were 1,093 eighth-grade students. The results revealed that 1) Analytical thinking ability scores…
Lyophilization: a useful approach to the automation of analytical processes?
de Castro, M. D. Luque; Izquierdo, A.
1990-01-01
An overview of the state-of-the-art in the use of lyophilization for the pretreatment of samples and standards prior to their storage and/or preconcentration is presented. The different analytical applications of this process are dealt with according to the type of material (reagent, standard, samples) and matrix involved.
Loop amplitudes in gauge theories: modern analytic approaches
Energy Technology Data Exchange (ETDEWEB)
Britto, Ruth, E-mail: ruth.britto@cea.fr [IPhT, CEA-Saclay, 91191 Gif-sur-Yvette Cedex (France)
2011-11-11
This article reviews on-shell methods for analytic computation of loop amplitudes, emphasizing techniques based on unitarity cuts. Unitarity techniques are formulated generally but have been especially useful for calculating one-loop amplitudes in massless theories such as Yang-Mills theory, QCD and QED. (review)
An Analytical Model for Learning: An Applied Approach.
Kassebaum, Peter Arthur
A mediated-learning package, geared toward non-traditional students, was developed for use in the College of Marin's cultural anthropology courses. An analytical model for learning was used in the development of the package, utilizing concepts related to learning objectives, programmed instruction, Gestalt psychology, cognitive psychology, and…
Video Analytics Evaluation: Survey of Datasets, Performance Metrics and Approaches
2014-09-01
corresponding to predefined positions and postures of the people. 200 snapshots in total http://imagelab.ing.unimore.it/visor/sarc3d.asp 9. 3DPES (3D... skeletons , 4) the 3d mesh (ply), 5) the estimated floor. 7.3 International Video Surveillance and Analytics Projects 1. CASSANDRA: Context Aware SenSing
Earth regeneration effect in solar neutrino oscillations an analytic approach
Lisi, E; Lisi, Eligio; Montanino, Daniele
1997-01-01
We present a simple and accurate method for computing analytically the regeneration probabilities of solar neutrinos in the Earth. We apply this method to the calculation of several solar model independent quantities t= han can be measured by the SuperKamiokande and Sudbury Neutrino Observatory experiments.
An analytical approach to managing complex process problems
Energy Technology Data Exchange (ETDEWEB)
Ramstad, Kari; Andersen, Espen; Rohde, Hans Christian; Tydal, Trine
2006-03-15
The oil companies are continuously investing time and money to ensure optimum regularity on their production facilities. High regularity increases profitability, reduces workload on the offshore organisation and most important; - reduces discharge to air and sea. There are a number of mechanisms and tools available in order to achieve high regularity. Most of these are related to maintenance, system integrity, well operations and process conditions. However, for all of these tools, they will only be effective if quick and proper analysis of fluids and deposits are carried out. In fact, analytical backup is a powerful tool used to maintain optimised oil production, and should as such be given high priority. The present Operator (Hydro Oil and Energy) and the Chemical Supplier (MI Production Chemicals) have developed a cooperation to ensure that analytical backup is provided efficiently to the offshore installations. The Operator's Research and Development (R and D) departments and the Chemical Supplier have complementary specialties in both personnel and equipment, and this is utilized to give the best possible service when required from production technologists or operations. In order for the Operator's Research departments, Health, Safety and Environment (HSE) departments and Operations to approve analytical work performed by the Chemical Supplier, a number of analytical tests are carried out following procedures agreed by both companies. In the present paper, three field case examples of analytical cooperation for managing process problems will be presented. 1) Deposition in a Complex Platform Processing System. 2) Contaminated Production Chemicals. 3) Improved Monitoring of Scale Inhibitor, Suspended Solids and Ions. In each case the Research Centre, Operations and the Chemical Supplier have worked closely together to achieve fast solutions and Best Practice. (author) (tk)
Two-component jet simulations: Combining analytical and numerical approaches
Matsakos, T; Trussoni, E; Tsinganos, K; Vlahakis, N; Sauty, C; Mignone, A
2009-01-01
Recent observations as well as theoretical studies of YSO jets suggest the presence of two steady components: a disk wind type outflow needed to explain the observed high mass loss rates and a stellar wind type outflow probably accounting for the observed stellar spin down. In this framework, we construct numerical two-component jet models by properly mixing an analytical disk wind solution with a complementary analytically derived stellar outflow. Their combination is controlled by both spatial and temporal parameters, in order to address different physical conditions and time variable features. We study the temporal evolution and the interaction of the two jet components on both small and large scales. The simulations reach steady state configurations close to the initial solutions. Although time variability is not found to considerably affect the dynamics, flow fluctuations generate condensations, whose large scale structures have a strong resemblance to observed YSO jet knots.
MODULAR ANALYTICS: A New Approach to Automation in the Clinical Laboratory
Horowitz, Gary L.; Zaman, Zahur; Blanckaert, Norbert J. C.; Chan, Daniel W.; Dubois, Jeffrey A.; Golaz, Olivier; Mensi, Noury; Keller, Franz; Stolz, Herbert; Klingler, Karl; Marocchi, Alessandro; Prencipe, Lorenzo; McLawhon, Ronald W.; Nilsen, Olaug L.; Oellerich, Michael
2005-01-01
MODULAR ANALYTICS (Roche Diagnostics) (MODULAR ANALYTICS, Elecsys and Cobas Integra are trademarks of a member of the Roche Group) represents a new approach to automation for the clinical chemistry laboratory. It consists of a control unit, a core unit with a bidirectional multitrack rack transportation system, and three distinct kinds of analytical modules: an ISE module, a P800 module (44 photometric tests, throughput of up to 800 tests/h), and a D2400 module (16 photometric tests, throughp...
‘Positioning’ in the conversation analytic approach
DEFF Research Database (Denmark)
Day, Dennis; Kjærbeck, Susanne
2013-01-01
From the perspective of ethnomethodology and conversation analysis (EM/CA), the concept of positioning may offer a compellingly rich and appealing metaphor for understanding identity and relations. However, a significant difference between positioning theory and EM/CA is that, while the concept...... of ‘positioning’ is used at all levels of analysis in the former, there appears to be no such analytical concept in EM/CA. The aim of this article is to inquire if EM/CA tools for the analysis of identities and relations in talk might be considered interesting from the perspective of positioning theory. To do so...
Heavy element stable isotope ratios: analytical approaches and applications.
Tanimizu, Masaharu; Sohrin, Yoshiki; Hirata, Takafumi
2013-03-01
Continuous developments in inorganic mass spectrometry techniques, including a combination of an inductively coupled plasma ion source and a magnetic sector-based mass spectrometer equipped with a multiple-collector array, have revolutionized the precision of isotope ratio measurements, and applications of inorganic mass spectrometry for biochemistry, geochemistry, and marine chemistry are beginning to appear on the horizon. Series of pioneering studies have revealed that natural stable isotope fractionations of many elements heavier than S (e.g., Fe, Cu, Zn, Sr, Ce, Nd, Mo, Cd, W, Tl, and U) are common on Earth, and it had been widely recognized that most physicochemical reactions or biochemical processes induce mass-dependent isotope fractionation. The variations in isotope ratios of the heavy elements can provide new insights into past and present biochemical and geochemical processes. To achieve this, the analytical community is actively solving problems such as spectral interference, mass discrimination drift, chemical separation and purification, and reduction of the contamination of analytes. This article describes data calibration and standardization protocols to allow interlaboratory comparisons or to maintain traceability of data, and basic principles of isotope fractionation in nature, together with high-selectivity and high-yield chemical separation and purification techniques for stable isotope studies.
Analytical approach to high harmonics spectrum in the nanobunching regime
Cherednychek, Mykyta
2016-01-01
With the high-order harmonic generation (HHG) from plasma sur- faces it is possible to turn a laser pulse into a train of attosecond or even zeptosecond pulses in the backward radiation. These attosecond pulses may have amplitude several orders of magnitude higher than that of the laser pulse under appropriate conditions. We study this process in detail, especially the nanobunching of the plasma electron density. We derive an analytical expression that describes the electron density pro- file and obtain a good agreement with particle-in-cell simulation results. We investigate the most efficient case of HHG at moderate laser intensity (I = 2*10^20 W/cm^2 ) on the over-dense plasma slab with an exponential profile pre-plasma. Subsequently we calculate the spectra of a single at- tosecond pulse from the backward radiation using our expression for the density shape in combination with the equation for the spectrum of the nanobunch radiation.
An analytic function approach to weak mutually unbiased bases
Olupitan, T.; Lei, C.; Vourdas, A.
2016-08-01
Quantum systems with variables in Z(d) are considered, and three different structures are studied. The first is weak mutually unbiased bases, for which the absolute value of the overlap of any two vectors in two different bases is 1 /√{ k } (where k | d) or 0. The second is maximal lines through the origin in the Z(d) × Z(d) phase space. The third is an analytic representation in the complex plane based on Theta functions, and their zeros. It is shown that there is a correspondence (triality) that links strongly these three apparently different structures. For simplicity, the case where d =p1 ×p2, where p1 ,p2 are odd prime numbers different from each other, is considered.
Contact angle of a hemispherical bubble: an analytical approach.
Teixeira, M A C; Teixeira, P I C
2009-10-01
We have calculated the equilibrium shape of the axially symmetric Plateau border along which a spherical bubble contacts a flat wall, by analytically integrating Laplace's equation in the presence of gravity, in the limit of small Plateau border sizes. This method has the advantage that it provides closed-form expressions for the positions and orientations of the Plateau border surfaces. Results are in very good overall agreement with those obtained from a numerical solution procedure, and are consistent with experimental data. In particular we find that the effect of gravity on Plateau border shape is relatively small for typical bubble sizes, leading to a widening of the Plateau border for sessile bubbles and to a narrowing for pendant bubbles. The contact angle of the bubble is found to depend even more weakly on gravity.
Integrated sampling and analytical approach for common groundwater dissolved gases.
McLeish, Kimberley; Ryan, M Cathryn; Chu, Angus
2007-12-15
A novel passive gas diffusion sampler (PGDS) combines sampling, storage and direct injection into a single gas chromatograph (GC). The sampler has a 4.5 mL internal volume when deployed, is easy to operate, and eliminates sample-partitioning. The associated GC method analyzes for a large, dynamic sampling range from a single, small volume injection. Dissolved gases were separated on parallel Rt-Molsieve 5A and Rt-Q-PLOT columns and eluted solutes were quantified using a pulse discharge helium ionization detector (PD-HID). The combined sampling and analytical method appears to be less prone to systematic bias than conventional sampling and headspace partitioning and analysis. Total dissolved gas pressure used in tandem with the PGDS improved the accuracy of dissolved gas concentrations. The incorporation of routine measurements of dissolved biogeochemical and permanent gases into groundwater investigations will provide increased insight into chemical and biological processes in groundwater and improve chemical mass balance accuracy.
Trends in Inflammatory Bowel Disease Therapy: A Meta-Analytic Approach
Directory of Open Access Journals (Sweden)
Gregory W Whiting
1995-01-01
Full Text Available OBJECTIVE: To illustrate the current meta-analytic approach to extracting clinically useful information from the glut of randomized controlled trials (RCTs of the treatment of acute attacks of Crohn's disease.
An analytical approach to the solution of the transport equation for photons
Energy Technology Data Exchange (ETDEWEB)
Reichert, Janice Teresinha, E-mail: janice.reichert@gmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Pato Branco, PR (Brazil); Barichello, Liliane Basso, E-mail: lbaric@mat.ufrgs.br [Universidade Federal do Rio Grande do Sul (UFRS), Porto Alegre, RS (Brazil)
2011-07-01
An analytical solution is developed to the one-dimensional transport equation for photons, for the case which includes spectral dependence. The Klein-Nishina kernel for Compton scattering is considered and an analytical discrete ordinates method, the ADO method, is used to solve the resulting angular dependent problem. Numerical simulations are performed to evaluate the buildup factor. (author)
DEFF Research Database (Denmark)
Hulbæk, Mette; Primdahl, Jette; Nielsen, Jesper Bo
2017-01-01
The Development of a Decision Aid with a Multi Criterial Analytic Approach for Women with Pelvic Organ Prolapse.......The Development of a Decision Aid with a Multi Criterial Analytic Approach for Women with Pelvic Organ Prolapse....
1995-05-01
A HYBRID ANALYTICAL/ SIMULATION MODELING APPROACH FOR PLANNING AND OPTIMIZING MASS TACTICAL AIRBORNE OPERATIONS by DAVID DOUGLAS BRIGGS M.S.B.A...COVERED MAY 1995 TECHNICAL REPORT THESIS 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS A HYBRID ANALYTICAL SIMULATION MODELING APPROACH FOR PLANNING AND...are present. Thus, simulation modeling presents itself as an excellent alternate tool for planning because it allows for the modeling of highly complex
Directory of Open Access Journals (Sweden)
Thaya Maranate
2015-01-01
Full Text Available Recently, there has been a problem of shortage of sleep laboratories that can accommodate the patients in a timely manner. Delayed diagnosis and treatment may lead to worse outcomes particularly in patients with severe obstructive sleep apnea (OSA. For this reason, the prioritization in polysomnography (PSG queueing should be endorsed based on disease severity. To date, there have been conflicting data whether clinical information can predict OSA severity. The 1,042 suspected OSA patients underwent diagnostic PSG study at Siriraj Sleep Center during 2010-2011. A total of 113 variables were obtained from sleep questionnaires and anthropometric measurements. The 19 groups of clinical risk factors consisting of 42 variables were categorized into each OSA severity. This study aimed to array these factors by employing Fuzzy Analytic Hierarchy Process approach based on normalized weight vector. The results revealed that the first rank of clinical risk factors in Severe, Moderate, Mild, and No OSA was nighttime symptoms. The overall sensitivity/specificity of the approach to these groups was 92.32%/91.76%, 89.52%/88.18%, 91.08%/84.58%, and 96.49%/81.23%, respectively. We propose that the urgent PSG appointment should include clinical risk factors of Severe OSA group. In addition, the screening for Mild from No OSA patients in sleep center setting using symptoms during sleep is also recommended (sensitivity = 87.12% and specificity = 72.22%.
A tiered analytical approach for investigating poor quality emergency contraceptives.
Monge, María Eugenia; Dwivedi, Prabha; Zhou, Manshui; Payne, Michael; Harris, Chris; House, Blaine; Juggins, Yvonne; Cizmarik, Peter; Newton, Paul N; Fernández, Facundo M; Jenkins, David
2014-01-01
Reproductive health has been deleteriously affected by poor quality medicines. Emergency contraceptive pills (ECPs) are an important birth control method that women can use after unprotected coitus for reducing the risk of pregnancy. In response to the detection of poor quality ECPs commercially available in the Peruvian market we developed a tiered multi-platform analytical strategy. In a survey to assess ECP medicine quality in Peru, 7 out of 25 different batches showed inadequate release of levonorgestrel by dissolution testing or improper amounts of active ingredient. One batch was found to contain a wrong active ingredient, with no detectable levonorgestrel. By combining ultrahigh performance liquid chromatography-ion mobility spectrometry-mass spectrometry (UHPLC-IMS-MS) and direct analysis in real time MS (DART-MS) the unknown compound was identified as the antibiotic sulfamethoxazole. Quantitation by UHPLC-triple quadrupole tandem MS (QqQ-MS/MS) indicated that the wrong ingredient was present in the ECP sample at levels which could have significant physiological effects. Further chemical characterization of the poor quality ECP samples included the identification of the excipients by 2D Diffusion-Ordered Nuclear Magnetic Resonance Spectroscopy (DOSY 1H NMR) indicating the presence of lactose and magnesium stearate.
A tiered analytical approach for investigating poor quality emergency contraceptives.
Directory of Open Access Journals (Sweden)
María Eugenia Monge
Full Text Available Reproductive health has been deleteriously affected by poor quality medicines. Emergency contraceptive pills (ECPs are an important birth control method that women can use after unprotected coitus for reducing the risk of pregnancy. In response to the detection of poor quality ECPs commercially available in the Peruvian market we developed a tiered multi-platform analytical strategy. In a survey to assess ECP medicine quality in Peru, 7 out of 25 different batches showed inadequate release of levonorgestrel by dissolution testing or improper amounts of active ingredient. One batch was found to contain a wrong active ingredient, with no detectable levonorgestrel. By combining ultrahigh performance liquid chromatography-ion mobility spectrometry-mass spectrometry (UHPLC-IMS-MS and direct analysis in real time MS (DART-MS the unknown compound was identified as the antibiotic sulfamethoxazole. Quantitation by UHPLC-triple quadrupole tandem MS (QqQ-MS/MS indicated that the wrong ingredient was present in the ECP sample at levels which could have significant physiological effects. Further chemical characterization of the poor quality ECP samples included the identification of the excipients by 2D Diffusion-Ordered Nuclear Magnetic Resonance Spectroscopy (DOSY 1H NMR indicating the presence of lactose and magnesium stearate.
Analytical approaches for arsenic determination in air: A critical review
Energy Technology Data Exchange (ETDEWEB)
Sánchez-Rodas, Daniel, E-mail: rodas@uhu.es [Centre for Research in Sustainable Chemistry-CIQSO, Associated Unit CSIC-University of Huelva “Atmospheric Pollution”, Campus El Carmen, University of Huelva, 21071 Huelva (Spain); Department of Chemistry and Materials Science, University of Huelva, 21071 Huelva (Spain); Sánchez de la Campa, Ana M. [Centre for Research in Sustainable Chemistry-CIQSO, Associated Unit CSIC-University of Huelva “Atmospheric Pollution”, Campus El Carmen, University of Huelva, 21071 Huelva (Spain); Department of Mining, Mechanic and Energetic Engineering, ETSI, University of Huelva, 21071 Huelva (Spain); Alsioufi, Louay [Centre for Research in Sustainable Chemistry-CIQSO, Associated Unit CSIC-University of Huelva “Atmospheric Pollution”, Campus El Carmen, University of Huelva, 21071 Huelva (Spain)
2015-10-22
This review describes the different steps involved in the determination of arsenic in air, considering the particulate matter (PM) and the gaseous phase. The review focuses on sampling, sample preparation and instrumental analytical techniques for both total arsenic determination and speciation analysis. The origin, concentration and legislation concerning arsenic in ambient air are also considered. The review intends to describe the procedures for sample collection of total suspended particles (TSP) or particles with a certain diameter expressed in microns (e.g. PM10 and PM2.5), or the collection of the gaseous phase containing gaseous arsenic species. Sample digestion of the collecting media for PM is described, indicating proposed and established procedures that use acids or mixtures of acids aided with different heating procedures. The detection techniques are summarized and compared (ICP-MS, ICP-OES and ET-AAS), as well those techniques capable of direct analysis of the solid sample (PIXE, INAA and XRF). The studies about speciation in PM are also discussed, considering the initial works that employed a cold trap in combination with atomic spectroscopy detectors, or the more recent studies based on chromatography (GC or HPLC) combined with atomic or mass detectors (AFS, ICP-MS and MS). Further trends and challenges about determination of As in air are also addressed. - Highlights: • Review about arsenic in the air. • Sampling, sample treatment and analysis of arsenic in particulate matter and gaseous phase. • Total arsenic determination and arsenic speciation analysis.
Analytical and statistical approaches in the characterization of synthetic polymers
Dimzon, I.K.
2015-01-01
Polymers vary in terms of the monomer/s used; the number, distribution and type of linkage of monomers per molecule; and the side chains and end groups attached. Given this diversity, traditional single-technique approaches to characterization often give limited and inadequate information about a
Newton Algorithms for Analytic Rotation: An Implicit Function Approach
Boik, Robert J.
2008-01-01
In this paper implicit function-based parameterizations for orthogonal and oblique rotation matrices are proposed. The parameterizations are used to construct Newton algorithms for minimizing differentiable rotation criteria applied to "m" factors and "p" variables. The speed of the new algorithms is compared to that of existing algorithms and to…
Newton Algorithms for Analytic Rotation: An Implicit Function Approach
Boik, Robert J.
2008-01-01
In this paper implicit function-based parameterizations for orthogonal and oblique rotation matrices are proposed. The parameterizations are used to construct Newton algorithms for minimizing differentiable rotation criteria applied to "m" factors and "p" variables. The speed of the new algorithms is compared to that of existing algorithms and to…
Unemployment and Causes of Hospital Admission Considering Different Analytical Approaches
DEFF Research Database (Denmark)
Berg-Beckhoff, Gabriele; Gulis, Gabriel; Kronborg Bak, Carsten
2016-01-01
The association between unemployment and hospital admission is known, but the causal relationship is still under discussion. The aim of the present analysis is to compare results of a cross-sectional and a cohort approach considering overall hospital admission and hospital admission due to cancer...... compensated unemployment and both types of disease specific hospital admission was associated statistically significant in the cross-sectional analysis. With regard to circulatory disease, the cohort approach suggests that social welfare compensated unemployment might lead to hospital admission due...... to the disease. Given the significant results in the cross-sectional analysis for hospital admission due to cancer, the unfound cohort effect might indicate a reverse causation suggesting that the disease caused joblessness and finally, social welfare compensated unemployment and not vice versa. Comparing...
Factors Influencing Attitudes Towards the Use of CRM’s Analytical Tools in Organizations
Directory of Open Access Journals (Sweden)
Šebjan Urban
2016-02-01
Full Text Available Background and Purpose: Information solutions for analytical customer relationship management CRM (aCRM IS that include the use of analytical tools are becoming increasingly important, due organizations’ need for knowledge of their customers and the ability to manage big data. The objective of the research is, therefore, to determine how the organizations’ orientations (process, innovation, and technology as critical organizational factors affect the attitude towards the use of the analytical tools of aCRM IS.
Colloca, Michele; Blanchard, Romane; Hellmich, Christian; Ito, Keita; van Rietbergen, Bert
2014-07-01
Bone is a dynamic and hierarchical porous material whose spatial and temporal mechanical properties can vary considerably due to differences in its microstructure and due to remodeling. Hence, a multiscale analytical approach, which combines bone structural information at multiple scales to the remodeling cellular activities, could form an efficient, accurate and beneficial framework for the prognosis of changes in bone properties due to, e.g., bone diseases. In this study, an analytical formulation of bone remodeling integrated with multiscale micromechanical models is proposed to investigate the effects of structural changes at the nanometer level (collagen scale) on those at higher levels (tissue scale). Specific goals of this study are to derive a mechanical stimulus sensed by the osteocytes using a multiscale framework, to test the accuracy of the multiscale model for the prediction of bone density, and to demonstrate its multiscale capabilities by predicting changes in bone density due to changes occurring at the molecular level. At each different level, the bone composition was modeled as a two-phase material which made it possible to: (1) find a closed-form solution for the energy-based mechanical stimulus sensed by the osteocytes and (2) describe the anisotropic elastic properties at higher levels as a function of the stiffness of the elementary components (collagen, hydroxyapatite and water) at lower levels. The accuracy of the proposed multiscale model of bone remodeling was tested first by comparing the analytical bone volume fraction predictions to those obtained from the corresponding μFE-based computational model. Differences between analytical and numerical predictions were less than 1% while the computational time was drastically reduced, namely by a factor of 1 million. In a further analysis, the effects of changes in collagen and hydroxyapatite volume fractions on the bone remodeling process were simulated, and it was found that such changes
Alexithymia and emotional regulation: A cluster analytical approach
Directory of Open Access Journals (Sweden)
Xu Ting
2011-02-01
Full Text Available Abstract Background Alexithymia has been a familiar conception of psychosomatic phenomenon. The aim of this study was to investigate whether there were subtypes of alexithymia associating with different traits of emotional expression and regulation among a group of healthy college students. Methods 1788 healthy college students were administered with the Chinese version of the 20-item Toronto Alexithymia Scale (TAS-20 and another set of questionnaires assessing emotion status and regulation. A hierarchical cluster analysis was conducted on the three factor scores of the TAS-20. The cluster solution was cross-validated by the corresponding emotional regulation. Results The results indicated there were four subtypes of alexithymia, namely extrovert-high alexithymia (EHA, general-high alexithymia (GHA, introvert-high alexithymia (IHA and non-alexithymia (NA. The GHA was characterized by general high scores on all three factors, the IHA was characterized by high scores on difficulty identifying feelings and difficulty describing feelings but low score on externally oriented cognitive style of thinking, the EHA was characterized by high score on externally oriented cognitive style of thinking but normal score on the others, and the NA got low score on all factors. The GHA and IHA were dominant by suppressive character of emotional regulation and expression with worse emotion status as compared to the EHA and NA. Conclusions The current findings suggest there were four subtypes of alexithymia characterized by different emotional regulation manifestations.
An analytical approach to the implementation of genetically modified crops
DEFF Research Database (Denmark)
Borch, K.; Rasmussen, B.
2000-01-01
Public scepticism towards genetically modified (GM) crops is increasing. To address this, the risks and benefits of GM crops must be examined across scientific disciplines, and be discussed with the authorities, the agricultural industry and the consumers. In a feasibility study we have...... systematically analysed the challenges of the development and marketing of GM crops in Europe. A life-cycle inventory was used together with established technology foresight techniques in an interdisciplinary and empirical framework. The approach taken in this study established a dialogue between stakeholders...... and provided a framework for discussions about the future direction of GM crops....
Why does informed consent fail? A discourse analytic approach.
Ness, David E; Kiesling, Scott F; Lidz, Charles W
2009-01-01
Informed consent often fails to meet the intended goals that a prospective subject should understand fully and choose autonomously to participate in research. The current study is an attempt to understand such failures by applying linguistic methods of discourse analysis to the transcripts of informed consent interviews. Elements of conversation and of the frame of discourse were analyzed to understand how the participants shaped their spoken interaction during the interview. We looked at the degree to which the subject appeared to be fully informed, at the problem of therapeutic misconception, and at the degree to which the subject was helped to explore concerns relevant to the choice at hand. We found that lapses or miscommunications could be understood specifically in terms of conversational elements and framing. This kind of detailed, language-based analysis is an alternative to approaches that are more abstract and inferential, such as those that are based upon the attitudes or the cognitive performance of speakers. We discuss possible educational and research implications of this approach.
Budsankom, Prayoonsri; Sawangboon, Tatsirin; Damrongpanit, Suntorapot; Chuensirimongkol, Jariya
2015-01-01
The purpose of the research is to develop and identify the validity of factors affecting higher order thinking skills (HOTS) of students. The thinking skills can be divided into three types: analytical, critical, and creative thinking. This analysis is done by applying the meta-analytic structural equation modeling (MASEM) based on a database of…
The EUROSTROKE cohorts: a short description and data analytical approach.
Bots, M L; Elwood, P C; Nikitin, Y; Salonen, J T; Freire de Concalves, A; Inzitari, D; Sivenius, J; Trichopoulou, A; Tuomilehto, J; Koudstaal, P J; Grobbee, D E
2002-02-01
This paper describes the design and methodology of the participating cohorts in the EUROSTROKE project. Information is given about the cohort sampling, its size, the follow up procedures and event classification. Information is also given about the measurement of the cardiovascular and cerebrovascular risk factors in each of the cohorts separately. The cohorts described are the Caerphilly study in Cardiff, United Kingdom; the Kuopio Ischaemic Heart disease study in Kuopio, Finland; the Portugal study in Coimbra, Portugal; the EPIC cohort in Athens, Greece; the Ilsa study from Firenze, Italy; the Rotterdam Study in Rotterdam, the Netherlands, and the Novosibirsk cohort in Novosibirsk, Russia.
Analytical Approach to Eigen-Emittance Evolution in Storage Rings
Energy Technology Data Exchange (ETDEWEB)
Nash, Boaz; /SLAC
2006-05-16
This dissertation develops the subject of beam evolution in storage rings with nearly uncoupled symplectic linear dynamics. Linear coupling and dissipative/diffusive processes are treated perturbatively. The beam distribution is assumed Gaussian and a function of the invariants. The development requires two pieces: the global invariants and the local stochastic processes which change the emittances, or averages of the invariants. A map based perturbation theory is described, providing explicit expressions for the invariants near each linear resonance, where small perturbations can have a large effect. Emittance evolution is determined by the damping and diffusion coefficients. The discussion is divided into the cases of uniform and non-uniform stochasticity, synchrotron radiation an example of the former and intrabeam scattering the latter. For the uniform case, the beam dynamics is captured by a global diffusion coefficient and damping decrement for each eigen-invariant. Explicit expressions for these quantities near coupling resonances are given. In many cases, they are simply related to the uncoupled values. Near a sum resonance, it is found that one of the damping decrements becomes negative, indicating an anti-damping instability. The formalism is applied to a number of examples, including synchrobetatron coupling caused by a crab cavity, a case of current interest where there is concern about operation near half integer {nu}{sub x}. In the non-uniform case, the moment evolution is computed directly, which is illustrated through the example of intrabeam scattering. Our approach to intrabeam scattering damping and diffusion has the advantage of not requiring a loosely-defined Coulomb Logarithm. It is found that in some situations there is a small difference between our results and the standard approaches such as Bjorken-Mtingwa, which is illustrated by comparison of the two approaches and with a measurement of Au evolution in RHIC. Finally, in combining IBS
Analytical approach to robust design of nonlinear mechanical systems
Institute of Scientific and Technical Information of China (English)
Jian ZHANG; Nengsheng BAO; Guojun ZHANG; Peihua GU
2009-01-01
The robustness of mechanical systems is influenced by various factors. Their effects must be understood for designing robust systems. This paper proposes a model for describing the relationships among functional requirements, structural characteristics, design parameters and uncontrollable variables of nonlinear systems. With this model, the ensitivity of systems was analyzed to formulate a system sensitivity index and robust sensitivity matrix to determine the importance of the factors in relation to the robustness of systems. Based on the robust design principle, an optimization model was developed. Combining this optimization model and the Taguchi method for robust design, annalysis as carried out to reveal the characteristics of the systems. For a nonlinear mechanical system, relationships among structural characteristics of the system, design parameters, and uncontrollable variables can be formulated as a mathematical function. The characteristics of the system determine how design parameters affect the functional equirements of the system. Consequently, they affect the distribution of system performance functions. Nonlinearity of the system can facilitate the selection of design parameters to achieve the required functional requirements.
Analytic Approach to Resolving Parking Problems in Downtown Zagreb
Directory of Open Access Journals (Sweden)
Adolf Malić
2005-01-01
Full Text Available Parking issue is one of the major problems in Zagreb, andin relation to that Zagreb does not differ from other similar orbigger European cities. The problem the city is facing is beingpresented in the paper. It is complex and can be solved gradually,using operative and planning measures, by applying influentialparameters assessments based on which the appropriateparking-garage spaces assessment would be selected. Besides,all the knowledge learned from experiences of similar Europeancities should be used in resolving stationary traffic problem.Introduction of fast public urban transport would providepassengers with improved services (particularly in relation tothe travelling time introducing modern traffic system thatwould reduce the travelling time to below 30 minutes for the farthestrelations. Further improvement in reducing parking problemsin downtown as well as Zagreb broader area would not bepossible without t,nplementing th.s approach.
Sulcus vocalis: a rational analytical approach to diagnosis and management.
Ford, C N; Inagi, K; Khidr, A; Bless, D M; Gilchrist, K W
1996-03-01
The term sulcus vocalis has been applied to a spectrum of disorders ranging from minor vocal fold indentations to destructive lesions causing severe dysphonia. To clarify the pathophysiology and to develop a more rational approach to treatment, we report a series of sulcus patients including 20 surgical cases. Clinical and histopathologic analysis produced a clinically useful classification: type 1 is a physiologic variant accentuated by atrophy but with intact lamina propria; types 2 (sulcus vergeture) and 3 (sulcus vocalis) are characterized by severe dysphonia, loss of vibratory activity, and destruction of the functional superficial lamina propria. These latter cases respond favorably to microsurgery designed to remove destroyed tissue, release scar contracture, and promote mucosal redraping by regional undermining. Further study of the extracellular matrix of the superficial lamina propria (Reinke's space) might indicate a common pathway in the pathogenesis of sulcus deformities and other related benign vocal fold lesions.
AN ANALYTICAL APPROACH TO GENERATE UNIQUE SONG SIGNAL (AUSS
Directory of Open Access Journals (Sweden)
Uttam Kr. Mondal
2013-02-01
Full Text Available Embedding uniqueness in characteristics of song signal and accustoming changes of environment is one of the challenging issues for researchers with maintaining its audible quality. Researchers are modifying or manipulating audio signal properties for generating uniqueness in content such a manner that will not vary so much in changed environment or changes can be easily defined due to unique structure of song signal. In this paper, an approach has been made based on defining a symmetric structure of song signal, followed by some secret code embedding in a specified manner will not alter the trade off ratio of embedding/modifying data but provide uniqueness in properties, even retain the properties in changing environment/ format. Therefore, authentication of song signal is easily achieved with these self manipulated properties. A comparative study has been made with similar existing techniques and experimental results are also supported with mathematical formula based on Microsoft WAVE (".wav" stereo sound file.
Analytic and probabilistic approaches to dynamics in negative curvature
Peigné, Marc; Sambusetti, Andrea
2014-01-01
The work of E. Hopf and G.A. Hedlund, in the 1930s, on transitivity and ergodicity of the geodesic flow for hyperbolic surfaces, marked the beginning of the investigation of the statistical properties and stochastic behavior of the flow. The first central limit theorem for the geodesic flow was proved in the 1960s by Y. Sinai for compact hyperbolic manifolds. Since then, strong relationships have been found between the fields of ergodic theory, analysis, and geometry. Different approaches and new tools have been developed to study the geodesic flow, including measure theory, thermodynamic formalism, transfer operators, Laplace operators, and Brownian motion. All these different points of view have led to a deep understanding of more general dynamical systems, in particular the so-called Anosov systems, with applications to geometric problems such as counting, equirepartition, mixing, and recurrence properties of the orbits. This book comprises two independent texts that provide a self-contained introduction t...
Directory of Open Access Journals (Sweden)
John C. Yi
2016-08-01
Full Text Available We investigate the impact of early adoption of an innovative analytics approach on organizational analytics maturity and sustainability. With the sales operation planning involving the accurate determination of physician detailing frequency, multiple product sequencing, nonlinear promotional response functions and achievement of the right level of share of voice (SOV, an analytical approach was developed by integrating domain knowledge, neural network (NN’s pattern-recognition capability and nonlinear mathematical programming to address these challenges. A pharmaceutical company headquartered in the U.S. championed this initial research in 2005 and became the first major firm to implement the recommendations. The company improved its profitability by 12% when piloted to a sales district with 481 physicians; then it launched this approach nationally. In 2014, the firm again gave us its data, performance of the analytical approach and access to key stakeholders to better understand the changes in the pharmaceutical sales operations landscape, the firm’s analytics maturity and sustainability of analytics. Results suggest that being the early adopter of innovation doubled the firm’s technology utilization from 2005 to 2014, as well as doubling the firm’s ability to continuously improve the sales operations process; it outperformed the standard industry practice by 23%. Moreover, the infusion of analytics from the corporate office to sales, improvement in management commitment to analytics, increased communications for continuous process improvement and the successes from this approach has created the environment for sustainable organizational growth in analytics.
An analytical approach for the Propagation Saw Test
Benedetti, Lorenzo; Fischer, Jan-Thomas; Gaume, Johan
2016-04-01
The Propagation Saw Test (PST) [1, 2] is an experimental in-situ technique that has been introduced to assess crack propagation propensity in weak snowpack layers buried below cohesive snow slabs. This test attracted the interest of a large number of practitioners, being relatively easy to perform and providing useful insights for the evaluation of snow instability. The PST procedure requires isolating a snow column of 30 centimeters of width and -at least-1 meter in the downslope direction. Then, once the stratigraphy is known (e.g. from a manual snow profile), a saw is used to cut a weak layer which could fail, potentially leading to the release of a slab avalanche. If the length of the saw cut reaches the so-called critical crack length, the onset of crack propagation occurs. Furthermore, depending on snow properties, the crack in the weak layer can initiate the fracture and detachment of the overlying slab. Statistical studies over a large set of field data confirmed the relevance of the PST, highlighting the positive correlation between test results and the likelihood of avalanche release [3]. Recent works provided key information on the conditions for the onset of crack propagation [4] and on the evolution of slab displacement during the test [5]. In addition, experimental studies [6] and simplified models [7] focused on the qualitative description of snowpack properties leading to different failure types, namely full propagation or fracture arrest (with or without slab fracture). However, beside current numerical studies utilizing discrete elements methods [8], only little attention has been devoted to a detailed analytical description of the PST able to give a comprehensive mechanical framework of the sequence of processes involved in the test. Consequently, this work aims to give a quantitative tool for an exhaustive interpretation of the PST, stressing the attention on important parameters that influence the test outcomes. First, starting from a pure
Analytic variance estimates of Swank and Fano factors.
Gutierrez, Benjamin; Badano, Aldo; Samuelson, Frank
2014-07-01
Variance estimates for detector energy resolution metrics can be used as stopping criteria in Monte Carlo simulations for the purpose of ensuring a small uncertainty of those metrics and for the design of variance reduction techniques. The authors derive an estimate for the variance of two energy resolution metrics, the Swank factor and the Fano factor, in terms of statistical moments that can be accumulated without significant computational overhead. The authors examine the accuracy of these two estimators and demonstrate how the estimates of the coefficient of variation of the Swank and Fano factors behave with data from a Monte Carlo simulation of an indirect x-ray imaging detector. The authors' analyses suggest that the accuracy of their variance estimators is appropriate for estimating the actual variances of the Swank and Fano factors for a variety of distributions of detector outputs. The variance estimators derived in this work provide a computationally convenient way to estimate the error or coefficient of variation of the Swank and Fano factors during Monte Carlo simulations of radiation imaging systems.
Analytic variance estimates of Swank and Fano factors
Energy Technology Data Exchange (ETDEWEB)
Gutierrez, Benjamin; Badano, Aldo; Samuelson, Frank, E-mail: frank.samuelson@fda.hhs.gov [US Food and Drug Administration, Silver Spring, Maryland 20993 (United States)
2014-07-15
Purpose: Variance estimates for detector energy resolution metrics can be used as stopping criteria in Monte Carlo simulations for the purpose of ensuring a small uncertainty of those metrics and for the design of variance reduction techniques. Methods: The authors derive an estimate for the variance of two energy resolution metrics, the Swank factor and the Fano factor, in terms of statistical moments that can be accumulated without significant computational overhead. The authors examine the accuracy of these two estimators and demonstrate how the estimates of the coefficient of variation of the Swank and Fano factors behave with data from a Monte Carlo simulation of an indirect x-ray imaging detector. Results: The authors' analyses suggest that the accuracy of their variance estimators is appropriate for estimating the actual variances of the Swank and Fano factors for a variety of distributions of detector outputs. Conclusions: The variance estimators derived in this work provide a computationally convenient way to estimate the error or coefficient of variation of the Swank and Fano factors during Monte Carlo simulations of radiation imaging systems.
Non-linear rheology of active particle suspensions: Insights from an analytical approach
Heidenreich, Sebastian; Hess, Siegfried; Klapp, Sabine H. L.
2010-01-01
We consider active suspensions in the isotropic phase subjected to a shear flow. Using a set of extended hydrodynamic equations we derive a variety of {\\em analytical} expressions for rheological quantities such as shear viscosity and normal stress differences. In agreement to full-blown numerical calculations and experiments we find a shear thickening or -thinning behaviour depending on whether the particles are contractile or extensile. Moreover, our analytical approach predicts that the no...
A measurement-based analytical approach to the bioluminescence tomography problem
Erkol, Hakan; Demirkiran, Aytac; Kipergil, Esra-Aytac; Uluc, Nasire; Unlu, Mehmet B.
2014-03-01
This work presents an analytical approach for the solution of the tissue diffusion equation based on the bound- ary measurements. We consider a bioluminescent point source in both homogeneous and heterogeneous circular turbid media. The point source is described by the Dirac delta function. Analytical expressions for the strength and position of the point source are obtained introducing boundary measurements and then applying appropriate boundary conditions. In addition, numerical simulations are performed for the position of the source. Calculations show that that the analytical results are in a good accordance with the numerical results.
Factor- Analytic Study of Performance on the Bender-Gestalt
Haynes, Jack R.
1970-01-01
College students were given the 16 Personality Factor Questionnaire, the Guilford Zimmerman Spatial Orientation and Spatial Visualization Tests, and the Bender Gestalt. Analyses revealed that personality characteristics were related to Bender performance and that the Bender was not measuring a unitary dimension of behavior. (Author)
A Factor Analytic Study of the Teaching Events Stress Inventory.
Alexander, Livingston; And Others
The purpose of this study was to determine if definitive factors emerge from the responses of teachers to the Teaching Events Stress Inventory (TESI). In a series of three studies during the years 1980 to 1982, data were collected to assess the levels and sources of stress experienced by 660 teachers in central and western Kentucky. The subjects…
A Factor Analytic Study of Inductive Reasoning Tests.
Ross, G. Robert
A set of eight widely used inductive reasoning tests were investigated to determine whether or not they have different factorial structures. The eight inductive tests and three deductive tests, taken from the French Kit of Reference Tests for Cognitive Factors and the Watson-Glaser Critical Thinking Appraisal, were administered to 157 high school…
A Factor Analytic Study of the Internet Usage Scale
Monetti, David M.; Whatley, Mark A.; Hinkle, Kerry T.; Cunningham, Kerry T.; Breneiser, Jennifer E.; Kisling, Rhea
2011-01-01
This study developed an Internet Usage Scale (IUS) for use with adolescent populations. The IUS is a 26-item scale that measures participants' beliefs about how their Internet usage impacts their behavior. The sample for this study consisted of 947 middle school students. An exploratory factor analysis with varimax rotation was conducted on the…
Human performance modeling for system of systems analytics: combat performance-shaping factors.
Energy Technology Data Exchange (ETDEWEB)
Lawton, Craig R.; Miller, Dwight Peter
2006-01-01
The US military has identified Human Performance Modeling (HPM) as a significant requirement and challenge of future systems modeling and analysis initiatives. To support this goal, Sandia National Laboratories (SNL) has undertaken a program of HPM as an integral augmentation to its system-of-system (SoS) analytics capabilities. The previous effort, reported in SAND2005-6569, evaluated the effects of soldier cognitive fatigue on SoS performance. The current effort began with a very broad survey of any performance-shaping factors (PSFs) that also might affect soldiers performance in combat situations. The work included consideration of three different approaches to cognition modeling and how appropriate they would be for application to SoS analytics. This bulk of this report categorizes 47 PSFs into three groups (internal, external, and task-related) and provides brief descriptions of how each affects combat performance, according to the literature. The PSFs were then assembled into a matrix with 22 representative military tasks and assigned one of four levels of estimated negative impact on task performance, based on the literature. Blank versions of the matrix were then sent to two ex-military subject-matter experts to be filled out based on their personal experiences. Data analysis was performed to identify the consensus most influential PSFs. Results indicate that combat-related injury, cognitive fatigue, inadequate training, physical fatigue, thirst, stress, poor perceptual processing, and presence of chemical agents are among the PSFs with the most negative impact on combat performance.
Directory of Open Access Journals (Sweden)
N. V. V. S. S. Raman
2015-01-01
Full Text Available Pharmaceutical industry has been emerging rapidly for the last decade by focusing on product Quality, Safety, and Efficacy. Pharmaceutical firms increased the number of product development by using scientific tools such as QbD (Quality by Design and PAT (Process Analytical Technology. ICH guidelines Q8 to Q11 have discussed QbD implementation in API synthetic process and formulation development. ICH Q11 guidelines clearly discussed QbD approach for API synthesis with examples. Generic companies are implementing QbD approach in formulation development and even it is mandatory for USFDA perspective. As of now there is no specific requirements for AQbD (Analytical Quality by Design and PAT in analytical development from all regulatory agencies. In this review, authors have discussed the implementation of QbD and AQbD simultaneously for API synthetic process and analytical methods development. AQbD key tools are identification of ATP (Analytical Target Profile, CQA (Critical Quality Attributes with risk assessment, Method Optimization and Development with DoE, MODR (method operable design region, Control Strategy, AQbD Method Validation, and Continuous Method Monitoring (CMM. Simultaneous implementation of QbD activities in synthetic and analytical development will provide the highest quality product by minimizing the risks and even it is very good input for PAT approach.
Khadivi, M R; Fatemi Ghomi, S M T
2012-06-01
Selection of the appropriate site for solid waste facilities is a complex problem and requires an extensive evaluation process, because it is very difficult to develop a selection criterion that can precisely describe the preference of one location over another. Therefore selection of these sites can be viewed as a multiple criteria decision-making or multiple attributes decision-making problem. For this purpose, we propose a technique that can effectively take managerial preferences and subjective data into consideration, along with quantitative factors. The tool proposed here relies on the use of the analytical network process (ANP) and to help integrate managerial evaluations into a more quantitatively based decision tool, data envelopment analysis (DEA) is applied. In this paper, a location selection procedure is presented to construct an undesirable facility applying ANP and DEA approaches in two stages. In the first stage ANP approach is used, results of this stage are inputs for the second stage. In this stage, DEA is applied to select the best location. Finally, to illustrate the proposed framework, at "Results and discussion" section, a total of four undesirable facility locations are evaluated. Copyright © 2012 Elsevier Ltd. All rights reserved.
Sources of Scientific Innovation: A Meta-Analytic Approach (Commentary on Simonton, 2009).
Sulloway, Frank J
2009-09-01
Innovations in science can be divided into at least four major types: radical revolutions (such as Copernican and Darwinian theory), technical revolutions (led by scientists such as Newton, Lavoisier, and Einstein), controversial innovations (for example, Semmelweis's theory of puerperal fever), and conservative innovations (eugenics and various vitalistic doctrines). Biographical predictors of support for scientific innovations are distinctly different depending on the type of innovation, as are the predictors of who initially engineers such innovations. A meta-analytic approach assessing each new scientific theory according to its salient features (including epistemological, ideological, and technical attributes) is required to make sense out of the varied predisposing factors associated with the origins of these innovations. These predisposing factors are not neatly classifiable in terms of Simonton's (2009, this issue) hierarchical model of domain-specific dispositions, although this model is applicable under some conditions. Instead, the principal sources of scientific achievement are largely a product of person-by-situation interaction effects that are dictated by the nature of the particular innovation.
Measurement and correlates of internalized homophobia: a factor analytic study.
Ross, M W; Rosser, B R
1996-01-01
We developed a scale to measure internalized homophobia in men who have sex with men, which is comprised of items derived from theoretical and clinical reports of internalized homophobia. Two hundred two men who have sex with men and who attend "Man to Man" sexual health seminars in a midwestern U.S. city completed the scale at baseline. Orthogonal factor analysis revealed four dimensions of internalized homophobia: public identification as gay, perception of stigma associated with being homosexual, social comfort with gay men, and the moral and religious acceptability of being gay. Factor scoring of these dimensions indicated that they were associated significantly with relationship satisfaction, duration of longest relationship, extent of attraction to men and women, proportion of social time with gay people, membership of gay/bisexual groups, HIV serostatus, and disclosure of sexual orientation. Internalized homophobia is measurable and consists of four dimensions that are associated significantly with low disclosure, shorter length of and satisfaction with relationships, lower degree of sexual attraction to men and higher degree of attraction to women, and lower social time with gay people.
Comparing factor analytic models of the DSM-IV personality disorders.
Huprich, Steven K; Schmitt, Thomas A; Richard, David C S; Chelminski, Iwona; Zimmerman, Mark A
2010-01-01
There is little agreement about the latent factor structure of the Diagnostic and Statistical Manual of Mental Disorders (DSM) personality disorders (PDs). Factor analytic studies over the past 2 decades have yielded different results, in part reflecting differences in factor analytic technique, the measure used to assess the PDs, and the changing DSM criteria. In this study, we explore the latent factor structure of the DSM (4th ed.; IV) PDs in a sample of 1200 psychiatric outpatients evaluated with the Structured Interview for DSM-IV PDs (B. Pfohl, N. Blum, & M. Zimmerman, 1997). We first evaluated 2 a priori models of the PDs with confirmatory factor analysis (CFA), reflecting their inherent organization in the DSM-IV: a 3-factor model and a 10-factor model. Fit statistics did not suggest that these models yielded an adequate fit. We then evaluated the latent structure with exploratory factor analysis (EFA). Multiple solutions produced more statistically and theoretically reasonable results, as well as providing clinically useful findings. On the basis of fit statistics and theory, 3 models were evaluated further--the 4-, 5-, and 10-factor models. The 10-factor model, which did not resemble the 10-factor model of the CFA, was determined to be the strongest of all 3 models. Future research should use contemporary methods of evaluating factor analytic results in order to more thoroughly compare various factor solutions.
Analytical approach of laser beam propagation in the hollow polygonal light pipe.
Zhu, Guangzhi; Zhu, Xiao; Zhu, Changhong
2013-08-10
An analytical method of researching the light distribution properties on the output end of a hollow n-sided polygonal light pipe and a light source with a Gaussian distribution is developed. The mirror transformation matrices and a special algorithm of removing void virtual images are created to acquire the location and direction vector of each effective virtual image on the entrance plane. The analytical method is demonstrated by Monte Carlo ray tracing. At the same time, four typical cases are discussed. The analytical results indicate that the uniformity of light distribution varies with the structural and optical parameters of the hollow n-sided polygonal light pipe and light source with a Gaussian distribution. The analytical approach will be useful to design and choose the hollow n-sided polygonal light pipe, especially for high-power laser beam homogenization techniques.
Topuz, Emel; van Gestel, Cornelis A M
2016-01-01
The usage of Engineered Nanoparticles (ENPs) in consumer products is relatively new and there is a need to conduct environmental risk assessment (ERA) to evaluate their impacts on the environment. However, alternative approaches are required for ERA of ENPs because of the huge gap in data and knowledge compared to conventional pollutants and their unique properties that make it difficult to apply existing approaches. This study aims to propose an ERA approach for ENPs by integrating Analytical Hierarchy Process (AHP) and fuzzy inference models which provide a systematic evaluation of risk factors and reducing uncertainty about the data and information, respectively. Risk is assumed to be the combination of occurrence likelihood, exposure potential and toxic effects in the environment. A hierarchy was established to evaluate the sub factors of these components. Evaluation was made with fuzzy numbers to reduce uncertainty and incorporate the expert judgements. Overall score of each component was combined with fuzzy inference rules by using expert judgements. Proposed approach reports the risk class and its membership degree such as Minor (0.7). Therefore, results are precise and helpful to determine the risk management strategies. Moreover, priority weights calculated by comparing the risk factors based on their importance for the risk enable users to understand which factor is effective on the risk. Proposed approach was applied for Ag (two nanoparticles with different coating) and TiO2 nanoparticles for different case studies. Results verified the proposed benefits of the approach.
Health Monitoring of a Rotating Disk Using a Combined Analytical-Experimental Approach
Abdul-Aziz, Ali; Woike, Mark R.; Lekki, John D.; Baaklini, George Y.
2009-01-01
Rotating disks undergo rigorous mechanical loading conditions that make them subject to a variety of failure mechanisms leading to structural deformities and cracking. During operation, periodic loading fluctuations and other related factors cause fractures and hidden internal cracks that can only be detected via noninvasive types of health monitoring and/or nondestructive evaluation. These evaluations go further to inspect material discontinuities and other irregularities that have grown to become critical defects that can lead to failure. Hence, the objectives of this work is to conduct a collective analytical and experimental study to present a well-rounded structural assessment of a rotating disk by means of a health monitoring approach and to appraise the capabilities of an in-house rotor spin system. The analyses utilized the finite element method to analyze the disk with and without an induced crack at different loading levels, such as rotational speeds starting at 3000 up to 10 000 rpm. A parallel experiment was conducted to spin the disk at the desired speeds in an attempt to correlate the experimental findings with the analytical results. The testing involved conducting spin experiments which, covered the rotor in both damaged and undamaged (i.e., notched and unnotched) states. Damaged disks had artificially induced through-thickness flaws represented in the web region ranging from 2.54 to 5.08 cm (1 to 2 in.) in length. This study aims to identify defects that are greater than 1.27 cm (0.5 in.), applying available means of structural health monitoring and nondestructive evaluation, and documenting failure mechanisms experienced by the rotor system under typical turbine engine operating conditions.
Bridge, Julia A
2017-01-01
The introduction of molecular testing into cytopathology laboratory practice has expanded the types of samples considered feasible for identifying genetic alterations that play an essential role in cancer diagnosis and treatment. Reverse transcription-polymerase chain reaction (RT-PCR), a sensitive and specific technical approach for amplifying a defined segment of RNA after it has been reverse-transcribed into its DNA complement, is commonly used in clinical practice for the identification of recurrent or tumor-specific fusion gene events. Real-time RT-PCR (quantitative RT-PCR), a technical variation, also permits the quantitation of products generated during each cycle of the polymerase chain reaction process. This review addresses qualitative and quantitative pre-analytic and analytic considerations of RT-PCR as they relate to various cytologic specimens. An understanding of these aspects of genetic testing is central to attaining optimal results in the face of the challenges that cytology specimens may present. Cancer Cytopathol 2017;125:11-19. © 2016 American Cancer Society.
McGill, Ryan J.; Canivez, Gary L.
2016-01-01
As recommended by Carroll, the present study examined the factor structure of the Wechsler Intelligence Scale for Children-Fourth Edition Spanish (WISC-IV Spanish) normative sample using higher order exploratory factor analytic techniques not included in the WISC-IV Spanish Technical Manual. Results indicated that the WISC-IV Spanish subtests were…
McGill, Ryan J.; Canivez, Gary L.
2016-01-01
As recommended by Carroll, the present study examined the factor structure of the Wechsler Intelligence Scale for Children-Fourth Edition Spanish (WISC-IV Spanish) normative sample using higher order exploratory factor analytic techniques not included in the WISC-IV Spanish Technical Manual. Results indicated that the WISC-IV Spanish subtests were…
A Multi-Level Middle-Out Cross-Zooming Approach for Large Graph Analytics
Energy Technology Data Exchange (ETDEWEB)
Wong, Pak C.; Mackey, Patrick S.; Cook, Kristin A.; Rohrer, Randall M.; Foote, Harlan P.; Whiting, Mark A.
2009-10-11
This paper presents a working graph analytics model that embraces the strengths of the traditional top-down and bottom-up approaches with a resilient crossover concept to exploit the vast middle-ground information overlooked by the two extreme analytical approaches. Our graph analytics model is developed in collaboration with researchers and users, who carefully studied the functional requirements that reflect the critical thinking and interaction pattern of a real-life intelligence analyst. To evaluate the model, we implement a system prototype, known as GreenHornet, which allows our analysts to test the theory in practice, identify the technological and usage-related gaps in the model, and then adapt the new technology in their work space. The paper describes the implementation of GreenHornet and compares its strengths and weaknesses against the other prevailing models and tools.
Knight, David B.; Brozina, Cory; Novoselich, Brian
2016-01-01
This paper investigates how first-year engineering undergraduates and their instructors describe the potential for learning analytics approaches to contribute to student success. Results of qualitative data collection in a first-year engineering course indicated that both students and instructors\temphasized a preference for learning analytics…
Optimal starting conditions for the rendezvous maneuver: Analytical and computational approach
Ciarcia, Marco
by the optimal trajectory. For the guidance trajectory, because of the replacement of the variable thrust direction of the powered subarc with a constant thrust direction, the optimal control problem degenerates into a mathematical programming problem with a relatively small number of degrees of freedom, more precisely: three for case (i) time-to-rendezvous free and two for case (ii) time-to-rendezvous given. In particular, we consider the rendezvous between the Space Shuttle (chaser) and the International Space Station (target). Once a given initial distance SS-to-ISS is preselected, the present work supplies not only the best initial conditions for the rendezvous trajectory, but simultaneously the corresponding final conditions for the ascent trajectory. In Part B, an analytical solution of the Clohessy-Wiltshire equations is presented (i) neglecting the change of the spacecraft mass due to the fuel consumption and (ii) and assuming that the thrust is finite, that is, the trajectory includes powered subarcs flown with max thrust and coasting subarc flown with zero thrust. Then, employing the found analytical solution, we study the rendezvous problem under the assumption that the initial separation coordinates and initial separation velocities are free except for the requirement that the initial chaser-to-target distance is given. The main contribution of Part B is the development of analytical solutions for the powered subarcs, an important extension of the analytical solutions already available for the coasting subarcs. One consequence is that the entire optimal trajectory can be described analytically. Another consequence is that the optimal control problems degenerate into mathematical programming problems. A further consequence is that, vis-a-vis the optimal control formulation, the mathematical programming formulation reduces the CPU time by a factor of order 1000. Key words. Space trajectories, rendezvous, optimization, guidance, optimal control, calculus of
Peeters, Carel F W; Dziura, James; van Wesel, Floryt
2014-10-01
Factor analysis (FA) has become part and parcel in metabolic syndrome (MBS) research. Both exploration- and confirmation-driven factor analyzes are rampant. However, factor analytic results on MBS differ widely. A situation that is at least in part attributable to misapplication of FA. Here, our purpose was (i) to review factor analytic efforts in the study of MBS with emphasis on misusage of the FA model and (ii) to propose an alternative factor analytic strategy. The proposed factor analytic strategy consists of four steps and confronts weaknesses in application of the FA model. At its heart lies the explicit separation of dimensionality and pattern selection and the direct evaluation of competing inequality-constrained loading patterns. A high-profile MBS data set with anthropometric measurements on overweight children and adolescents is reanalyzed using this strategy. The reanalysis implied a more parsimonious constellation of pathophysiological domains underlying phenotypic expressions of MBS than the original analysis (and many other analyses). The results emphasize correlated factors of impaired glucose metabolism and impaired lipid metabolism. Pathophysiological domains underlying phenotypic expressions of MBS included in the analysis are driven by multiple interrelated metabolic impairments. These findings indirectly point to the possible existence of a multifactorial etiology. Copyright © 2014 Elsevier Inc. All rights reserved.
2011-12-01
more analytical schedule could offer consistency be- tween maintenance units and remove the manual input factor that is currently used. We found that...Technical Infor- mation Center: AD- A320 502/8. AUTHOR BIOGRAPHIES STEPHANIE C. YSEBAERT is an operations research analyst and First Lieutenant in
Nonlinear rheology of active particle suspensions: insights from an analytical approach.
Heidenreich, Sebastian; Hess, Siegfried; Klapp, Sabine H L
2011-01-01
We consider active suspensions in the isotropic phase subjected to a shear flow. Using a set of extended hydrodynamic equations we derive a variety of analytical expressions for rheological quantities such as shear viscosity and normal stress differences. In agreement to full-blown numerical calculations and experiments we find a shear-thickening or -thinning behavior depending on whether the particles are contractile or extensile. Moreover, our analytical approach predicts that the normal stress differences can change their sign in contrast to passive suspensions.
Two Approaches in the Lunar Libration Theory: Analytical vs. Numerical Methods
Petrova, Natalia; Zagidullin, Arthur; Nefediev, Yurii; Kosulin, Valerii
2016-10-01
Observation of the physical libration of the Moon and the celestial bodies is one of the astronomical methods to remotely evaluate the internal structure of a celestial body without using expensive space experiments. Review of the results obtained due to the physical libration study, is presented in the report.The main emphasis is placed on the description of successful lunar laser ranging for libration determination and on the methods of simulating the physical libration. As a result, estimation of the viscoelastic and dissipative properties of the lunar body, of the lunar core parameters were done. The core's existence was confirmed by the recent reprocessing of seismic data Apollo missions. Attention is paid to the physical interpretation of the phenomenon of free libration and methods of its determination.A significant part of the report is devoted to describing the practical application of the most accurate to date the analytical tables of lunar libration built by comprehensive analytical processing of residual differences obtained when comparing the long-term series of laser observations with numerical ephemeris DE421 [1].In general, the basic outline of the report reflects the effectiveness of two approaches in the libration theory - numerical and analytical solution. It is shown that the two approaches complement each other for the study of the Moon in different aspects: numerical approach provides high accuracy of the theory necessary for adequate treatment of modern high-accurate observations and the analytic approach allows you to see the essence of the various kind manifestations in the lunar rotation, predict and interpret the new effects in observations of physical libration [2].[1] Rambaux, N., J. G. Williams, 2011, The Moon's physical librations and determination of their free modes, Celest. Mech. Dyn. Astron., 109, 85-100.[2] Petrova N., A. Zagidullin, Yu. Nefediev. Analysis of long-periodic variations of lunar libration parameters on the basis of
Nonrelativistic QED approach to the bound-electron g factor
Pachucki, K; Yerokhin, V A
2004-01-01
Within a systematic approach based on nonrelativistic quantum electrodynamics (NRQED), we derive the one-loop self-energy correction of order alpha (Zalpha)^4 to the bound-electron g factor. In combination with numerical data, this analytic result improves theoretical predictions for the self-energy correction for carbon and oxygen by an order of magnitude. Basing on one-loop calculations, we obtain the logarithmic two-loop contribution of order alpha^2 (Zalpha)^4 ln[(Zalpha)^-2] and the dominant part of the corresponding constant term. The results obtained improve the accuracy of the theoretical predictions for the 1S bound-electron g factor and influence the value of the electron mass determined from g factor measurements.
Nonrelativistic QED Approach to the Bound-Electron g Factor
Pachucki, Krzysztof; Jentschura, Ulrich D.; Yerokhin, Vladimir A.
2004-10-01
Within a systematic approach based on nonrelativistic quantum electrodynamics, we derive the one-loop self-energy correction of order α(Zα)4 to the bound-electron g factor. In combination with numerical data, this analytic result improves theoretical predictions for the self-energy correction for carbon and oxygen by an order of magnitude. Basing on one-loop calculations, we obtain the logarithmic two-loop contribution of order α2(Zα)4ln([(Zα)-2] and the dominant part of the corresponding constant term. The results obtained improve the accuracy of the theoretical predictions for the 1S bound-electron g factor and influence the value of the electron mass determined from g-factor measurements.
Prioritizing the client trust factors in electronic banking using analytic hierarchy process
Directory of Open Access Journals (Sweden)
Hossein vazifedust
2014-04-01
Full Text Available This paper prioritizes the trust factors among electronic banking clients of an Iranian bank named Parsian Bank. The study first analyzes and reviews the literature and interviews with experts of electronic banking and academicians and determines client trust as the most important factor for development of electronic banking. The study also determines different factors associated with trust, which includes individual factors, banking factors and infrastructural factors. The sample populations consist of 25 experts who are academicians, managers and bank officers, clients of electronic banking. The necessary data was collected through conducting interviews and questionnaires and they are analyzed using analytic hierarchy process (AHP. The research findings indicate that the attitudinal factors, telecommunication infrastructure and cultural factors were the most influential factors accordingly and the customer orientation and ease of access were the least influential factors.
Directory of Open Access Journals (Sweden)
Klimenta Dardan O.
2017-01-01
Full Text Available The purpose of this paper is to propose a novel approach to analytical modelling of steady-state heat transfer from the exterior of totally enclosed fan-cooled induction motors. The proposed approach is based on the geometry simplification methods, energy balance equation, modified correlations for forced convection, the Stefan-Boltzmann law, air-flow velocity profiles, and turbulence factor models. To apply modified correlations for forced convection, the motor exterior is presented with surfaces of elementary 3-D shapes as well as the air-flow velocity profiles and turbulence factor models are introduced. The existing correlations for forced convection from a short horizontal cylinder and correlations for heat transfer from straight fins (as well as inter-fin surfaces in axial air-flows are modified by introducing the Prandtl number to the appropriate power. The correlations for forced convection from straight fins and inter-fin surfaces are derived from the existing ones for combined heat transfer (due to forced convection and radiation by using the forced-convection correlations for a single flat plate. Employing the proposed analytical approach, satisfactory agreement is obtained with experimental data from other studies.
Institute of Scientific and Technical Information of China (English)
G. Darmani; S. Setayeshi; H. Ramezanpour
2012-01-01
In this paper an efficient computational method based on extending the sensitivity approach （SA） is proposed to find an analytic exact solution of nonlinear differential difference equations. In this manner we avoid solving the nonlinear problem directly. By extension of sensitivity approach for differential difference equations （DDEs）, the nonlinear original problem is transformed into infinite linear differential difference equations, which should be solved in a recursive manner. Then the exact solution is determined in the form of infinite terms series and by intercepting series an approximate solution is obtained. Numerical examples are employed to show the effectiveness of the proposed approach.
Arpaia, Pasquale
2009-01-01
An approach to automatic analytical modeling of electrochemical impedance spectroscopy data by evolutionary programming based on cultural algorithms is proposed. A solution-search strategy based on a cultural mechanism is exploited for defining the equivalent-circuit model automatically: information on search advance is transmitted to all potential solutions, rather than only to a small inheriting subset, such as in a traditional genetic approach. Moreover, with respect to the state of the art, also specific information related to constraints on the application physics knowledge is transferred. Experimental results of the proposed approach implementation in impedance spectroscopy for general-purpose electrochemical circuit analysis and for corrosion monitoring and diagnosing are presented.
Stability Analysis of Magnetised Neutron Stars - A Semi-analytic Approach
Herbrik, Marlene
2015-01-01
We implement a semi-analytic approach for stability analysis, addressing the ongoing uncertainty about stability and structure of neutron star magnetic fields. Applying the energy variational principle, a model system is displaced from its equilibrium state. The related energy density variation is set up analytically, whereas its volume integration is carried out numerically. This facilitates the consideration of more realistic neutron star characteristics within the model compared to analytical treatments. At the same time, our method retains the possibility to yield general information about neutron star magnetic field and composition structures that are likely to be stable. In contrast to numerical studies, classes of parametrized systems can be studied at once, finally constraining realistic configurations for interior neutron star magnetic fields. We apply the stability analysis scheme on polytropic and non-barotropic neutron stars with toroidal, poloidal and mixed fields testing their stability in a New...
Sharma, Dharmendar Kumar; Irfanullah, Mir; Basu, Santanu Kumar; Madhu, Sheri; De, Suman; Jadhav, Sameer; Ravikanth, Mangalampalli; Chowdhury, Arindam
2017-03-01
While fluorescence microscopy has become an essential tool amongst chemists and biologists for the detection of various analyte within cellular environments, non-uniform spatial distribution of sensors within cells often restricts extraction of reliable information on relative abundance of analytes in different subcellular regions. As an alternative to existing sensing methodologies such as ratiometric or FRET imaging, where relative proportion of analyte with respect to the sensor can be obtained within cells, we propose a methodology using spectrally-resolved fluorescence microscopy, via which both the relative abundance of sensor as well as their relative proportion with respect to the analyte can be simultaneously extracted for local subcellular regions. This method is exemplified using a BODIPY sensor, capable of detecting mercury ions within cellular environments, characterized by spectral blue-shift and concurrent enhancement of emission intensity. Spectral emission envelopes collected from sub-microscopic regions allowed us to compare the shift in transition energies as well as integrated emission intensities within various intracellular regions. Construction of a 2D scatter plot using spectral shifts and emission intensities, which depend on the relative amount of analyte with respect to sensor and the approximate local amounts of the probe, respectively, enabled qualitative extraction of relative abundance of analyte in various local regions within a single cell as well as amongst different cells. Although the comparisons remain semi-quantitative, this approach involving analysis of multiple spectral parameters opens up an alternative way to extract spatial distribution of analyte in heterogeneous systems. The proposed method would be especially relevant for fluorescent probes that undergo relatively nominal shift in transition energies compared to their emission bandwidths, which often restricts their usage for quantitative ratiometric imaging in
Institute of Scientific and Technical Information of China (English)
LI Ming; WANG Ming; RONG Hua; LI Hong-Pu
2006-01-01
@@ An optical microelectromechanical-system (MEMS) pressure sensor based on multi-layer circular diaphragm is described and analysed by using the proposed novel analytical approach and the traditional transfer matrix method. The analytical expressions of the deflection of multi-layer diaphragm and absolute optical reflectance are derived respectively. The influence of residual stress on the deflection of diaphragm is also analysed. Simulation results given by the finite element method are consistent with the ones which are analysed by using the analytical approach. The analytical approach will be helpful to design and fabricate the optical MEMS pressure sensors with multi-layer diaphragm based on Fabry-Perot interferometry.
Analytical approach to the D3-brane gravity dual for 3d Yang-Mills theory
Forkel, Hilmar
2015-01-01
The complexity of "top-down" string-dual candidates for strongly-coupled Yang-Mills theories and in particular for QCD almost always prohibits their exact analytical or even comprehensive numerical treatment. This impedes both a thorough quantitative analysis and the development of more realistic gravity duals. To mitigate these impediments, we devise an analytical approach to top-down duals on the basis of controlled, uniformly converging high-accuracy approximations for the normalizable string modes corresponding to gauge-theory states. We demonstrate the potential of this approach in Witten's dual for $3d$ Yang-Mills theory, i.e. in the near-horizon limit of non-extremal $D\\text{3}$-branes, compactified on $S^{1}$. We obtain accurate analytical approximations to the bulk modes which satisfy the boundary conditions exactly. On their basis, analytical results for masses, sizes, pole residues and correlation functions of glueball excitations are derived by spectral methods. These approximations can be systema...
An analytically based numerical method for computing view factors in real urban environments
Lee, Doo-Il; Woo, Ju-Wan; Lee, Sang-Hyun
2016-11-01
A view factor is an important morphological parameter used in parameterizing in-canyon radiative energy exchange process as well as in characterizing local climate over urban environments. For realistic representation of the in-canyon radiative processes, a complete set of view factors at the horizontal and vertical surfaces of urban facets is required. Various analytical and numerical methods have been suggested to determine the view factors for urban environments, but most of the methods provide only sky-view factor at the ground level of a specific location or assume simplified morphology of complex urban environments. In this study, a numerical method that can determine the sky-view factors (ψ ga and ψ wa ) and wall-view factors (ψ gw and ψ ww ) at the horizontal and vertical surfaces is presented for application to real urban morphology, which are derived from an analytical formulation of the view factor between two blackbody surfaces of arbitrary geometry. The established numerical method is validated against the analytical sky-view factor estimation for ideal street canyon geometries, showing a consolidate confidence in accuracy with errors of less than 0.2 %. Using a three-dimensional building database, the numerical method is also demonstrated to be applicable in determining the sky-view factors at the horizontal (roofs and roads) and vertical (walls) surfaces in real urban environments. The results suggest that the analytically based numerical method can be used for the radiative process parameterization of urban numerical models as well as for the characterization of local urban climate.
A confirmatory factor analytic study of a self-leadership measure in South Africa
Directory of Open Access Journals (Sweden)
Bright Mahembe
2013-01-01
Full Text Available Orientation: Self-leadership is considered to be essential for effective individual functioning in occupational and academic contexts. The revised self-leadership questionnaire (RSLQ is widely utilised for measuring self-leadership, but its psychometric properties have not been established on a South African sample. By implication, important questions also exist about the theoretical structure of self-leadership in the South African context. Research purpose: The research aim of this study was to investigate the reliability and factorial validity of the revised self-leadership questionnaire on a South African sample. In doing so, the results of the research would also provide valuable insights into the latent factor structure of the self-leadership construct. Motivation for the study: On a practical level, the research sought internal validity evidence for the use of the RSLQ in the South African context. On a theoretical level, questions remain about the best conceptual representation of self-leadership as a construct. Research design, approach and method: The revised self-leadership questionnaire was administered to a non-probability sample of 375 South African young adults. The first and second-order factor structure underlying contemporary models of self-leadership using confirmatory factor analytic techniques was tested. Main findings: Results showed that the RSLQ measured self-leadership with suitable reliability and internal validity. All eight subscales had high internal consistency coefficients. Confirmatory factor analysis (CFA of the first and second-order models conclusively demonstrated good factorial validity. Practical/managerial implications: The study found that the RSLQ has good measurement properties for a South African context. Academics, practitioners and managers are urged to use the measure in its present form for applications such as leadership development and promoting self-management. Contribution/value-addition: The
Modelling and assessment of dependent performance shaping factors through Analytic Network Process
Energy Technology Data Exchange (ETDEWEB)
De Ambroggi, Massimiliano, E-mail: massimiliano.deambroggi@mail.polimi.i [Politecnico di Milano, Department of Management, Economics and Industrial Engineering, Piazza Leonardo da Vinci 32, Milan 20132 (Italy); Trucco, Paolo [Politecnico di Milano, Department of Management, Economics and Industrial Engineering, Piazza Leonardo da Vinci 32, Milan 20132 (Italy)
2011-07-15
Despite continuous progresses in research and applications, one of the major weaknesses of current HRA methods dwells in their limited capability of modelling the mutual influences between performance shaping factors (PSFs). Indeed at least two types of dependencies between PSFs can be defined: (i) dependency between the states of the PSFs; (ii) dependency between the influences (impacts) of the PSFs on the human performance. This paper introduces a method, based on Analytic Network Process (ANP), for the quantification of the latter, where the overall contribution of each PSF (weight) to the human error probability (HEP) is eventually returned. The core of the method is the modelling process, articulated into two steps: firstly, a qualitative network of dependencies between PSFs is identified, then, the importance of each PSF is quantitatively assessed using ANP. The model allows to distinguish two components of the PSF influence: direct influence that is the influence that the considered PSF is able to express by itself, notwithstanding the presence of other PSFs and indirect influence that is the incremental influence of the considered PSF through its influence on other PSFs. A case study in Air Traffic Control is presented where the proposed approach is integrated into the cognitive simulator PROCOS. The results demonstrated a significant modification of the influence of PSFs over the operator performance when dependencies are taken into account, underlining the importance of considering not only the possible correlation between the states of PSFs but also their mutual dependency in affecting human performance in complex systems.
Vagos, Paula; Rijo, Daniel; Santos, Isabel M
2016-04-01
Relatively little is known about measures used to investigate the validity and applications of social information processing theory. The Scenes for Social Information Processing in Adolescence includes items built using a participatory approach to evaluate the attribution of intent, emotion intensity, response evaluation, and response decision steps of social information processing. We evaluated a sample of 802 Portuguese adolescents (61.5% female; mean age = 16.44 years old) using this instrument. Item analysis and exploratory and confirmatory factor analytic procedures were used for psychometric examination. Two measures for attribution of intent were produced, including hostile and neutral; along with 3 emotion measures, focused on negative emotional states; 8 response evaluation measures; and 4 response decision measures, including prosocial and impaired social behavior. All of these measures achieved good internal consistency values and fit indicators. Boys seemed to favor and choose overt and relational aggression behaviors more often; girls conveyed higher levels of neutral attribution, sadness, and assertiveness and passiveness. The Scenes for Social Information Processing in Adolescence achieved adequate psychometric results and seems a valuable alternative for evaluating social information processing, even if it is essential to continue investigation into its internal and external validity.
A Bayesian Multi-Level Factor Analytic Model of Consumer Price Sensitivities across Categories
Duvvuri, Sri Devi; Gruca, Thomas S.
2010-01-01
Identifying price sensitive consumers is an important problem in marketing. We develop a Bayesian multi-level factor analytic model of the covariation among household-level price sensitivities across product categories that are substitutes. Based on a multivariate probit model of category incidence, this framework also allows the researcher to…
A General Factor-Analytic Procedure for Assessing Response Bias in Questionnaire Measures
Ferrando, Pere J.; Lorenzo-Seva, Urbano; Chico, Eliseo
2009-01-01
This article proposes procedures for simultaneously assessing and controlling acquiescence and social desirability in questionnaire items. The procedures are based on a semi-restricted factor-analytic tridimensional model, and can be used with binary, graded-response, or more continuous items. We discuss procedures for fitting the model (item…
A Bayesian Multi-Level Factor Analytic Model of Consumer Price Sensitivities across Categories
Duvvuri, Sri Devi; Gruca, Thomas S.
2010-01-01
Identifying price sensitive consumers is an important problem in marketing. We develop a Bayesian multi-level factor analytic model of the covariation among household-level price sensitivities across product categories that are substitutes. Based on a multivariate probit model of category incidence, this framework also allows the researcher to…
Blind source separation of fMRI data by means of factor analytic transformations
Langers, Dave R. M.
2009-01-01
In this study, the application of factor analytic (FA) rotation methods in the context of neuroimaging data analysis was explored. Three FA algorithms (ProMax, QuartiMax, and VariMax) were employed to carry out blind source separation in a functional magnetic resonance imaging (fMRI) experiment that
Beyond Engagement Analytics: Which Online Mixed-Data Factors Predict Student Learning Outcomes?
Strang, Kenneth David
2017-01-01
This mixed-method study focuses on online learning analytics, a research area of importance. Several important student attributes and their online activities are examined to identify what seems to work best to predict higher grades. The purpose is to explore the relationships between student grade and key learning engagement factors using a large…
Blind source separation of fMRI data by means of factor analytic transformations
Langers, Dave R. M.
2009-01-01
In this study, the application of factor analytic (FA) rotation methods in the context of neuroimaging data analysis was explored. Three FA algorithms (ProMax, QuartiMax, and VariMax) were employed to carry out blind source separation in a functional magnetic resonance imaging (fMRI) experiment that
Analytical approach and field monitoring for mechanical behaviors of pipe roof reinforcement
Institute of Scientific and Technical Information of China (English)
WANG Hai-tao; JIA Jin-qing; KANG Hai-gui
2009-01-01
Considering the delay effect of initial lining and revising the Winkler elastic foundation model, an analytical approach based on Pasternak elastic foundation beam theory for pipe roof reinforcement was put forward. With the example of a certain tunnel excavation, the comparison of the values of longitudinal strain of reinforcing pipe between field monitoring and analytical approach was made. The results indicate that Pasternak model, which considers a more realistic hypothesis in the elastic soil than Winkler model, gives more accurate calculation and agrees better with the result of field monitoring. The difference of calculation results between these two models is about 7%, and Pasternak model is proved to be a better way to study the reinforcement mechanism and improve design practice. The calculation results also reveal that the reinforcing pipes act as levers, which increases longitudinal load transfer to an unexcavated area, and consequently decreases deformation and increases face stability.
On Statistical Approaches for Demonstrating Analytical Similarity in the Presence of Correlation.
Yang, Harry; Novick, Steven; Burdick, Richard K
Analytical similarity is the foundation for demonstration of biosimilarity between a proposed product and a reference product. For this assessment, currently the U.S. Food and Drug Administration (FDA) recommends a tiered system in which quality attributes are categorized into three tiers commensurate with their risk and approaches of varying statistical rigor are subsequently used for the three-tier quality attributes. Key to the analyses of Tiers 1 and 2 quality attributes is the establishment of equivalence acceptance criterion and quality range. For particular licensure applications, the FDA has provided advice on statistical methods for demonstration of analytical similarity. For example, for Tier 1 assessment, an equivalence test can be used based on an equivalence margin of 1.5 σR, where σR is the reference product variability estimated by the sample standard deviation SR from a sample of reference lots. The quality range for demonstrating Tier 2 analytical similarity is of the form X̄R ± K × σR where the constant K is appropriately justified. To demonstrate Tier 2 analytical similarity, a large percentage (e.g., 90%) of test product must fall in the quality range. In this paper, through both theoretical derivations and simulations, we show that when the reference drug product lots are correlated, the sample standard deviation SR underestimates the true reference product variability σR As a result, substituting SR for σR in the Tier 1 equivalence acceptance criterion and the Tier 2 quality range inappropriately reduces the statistical power and the ability to declare analytical similarity. Also explored is the impact of correlation among drug product lots on Type I error rate and power. Three methods based on generalized pivotal quantities are introduced, and their performance is compared against a two-one-sided tests (TOST) approach. Finally, strategies to mitigate risk of correlation among the reference products lots are discussed. A biosimilar is
SPf66 vaccine trial in Brazil: conceptual framework study design and analytical approach
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M. Urdaneta
1996-06-01
Full Text Available This paper describes the study population and the study design of the phase III field trial of the SPf66 vaccine in Brazil. Assessment of validity and precision principles necessary for the appropriate evaluation of the protective effect of the vaccine are discussed, as well as the results of the preliminary analyses of the gathered data. The analytical approach for the estimation of the protective effect of the vaccine is presented. This paper provides the conceptual framework for future publications.
A Streamlined Approach to Solving Simple and Complex Kinetic Systems Analytically
Andraos, John
1999-11-01
The use of Laplace transforms and integration techniques for the solution of simultaneous differential equations is demonstrated for obtaining the analytical solutions of simple and complex kinetic systems well known to students of the chemical sciences. These techniques learned in core first- and second-year mathematics courses provide a firm grounding in students' ability to understand the derivation of various rate expressions, and illustrate the value of cross-disciplinary approaches to education between the chemical and mathematical sciences.
Kefi, Hajer; Indra, Sitesh; Abdessalem, Talel
2017-01-01
We present in this paper a multicultural approach to social media marketing analytics, applied in two Facebook brand pages: French (individualistic culture, the country home of the brand) versus Saudi Arabian (collectivistic culture, one of its country hosts), which are published by an internationalbeauty \\& cosmetics firm. Using social network analysis and content analysis, we identify the most popular posts and the most influential users within these two brand pages and highlight the differ...
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Rainer Diaz-Bone
2006-05-01
Full Text Available Abstract: The German discourse researcher Siegfried JÄGER from Duisburg is the first to have published a German-language book about the methodology of discourse analysis after FOUCAULT. JÄGER integrates in his work the discourse analytic work of Jürgen LINK as well as the interdisciplinary discussion carried on in the discourse analytic journal "kultuRRevolution" (Journal for Applied Discourse Analysis. JÄGER and his co-workers were associated with the Duisburger Institute for Language Research and Social Research (DISS, see http://www.diss-duisburg.de/ for 20 years, developing discourse theory and the methodology of discourse analysis. The interview was done via e-mail. It depicts the discourse analytic approach of JÄGER and his co-workers following the works of FOUCAULT and LINK. The interview reconstructs JÄGERs vita and his academic career. Further topics of the interview are the agenda of JÄGERs discourse studies, methodological considerations, the (problematic relationship between FOUCAULDian discourse analysis and (discourses, linguistics, styles and organization of research and questions concerning applied discourse analytic research as a form of critical intervention. URN: urn:nbn:de:0114-fqs0603219
Chiadamrong, N.; Piyathanavong, V.
2017-04-01
Models that aim to optimize the design of supply chain networks have gained more interest in the supply chain literature. Mixed-integer linear programming and discrete-event simulation are widely used for such an optimization problem. We present a hybrid approach to support decisions for supply chain network design using a combination of analytical and discrete-event simulation models. The proposed approach is based on iterative procedures until the difference between subsequent solutions satisfies the pre-determined termination criteria. The effectiveness of proposed approach is illustrated by an example, which shows closer to optimal results with much faster solving time than the results obtained from the conventional simulation-based optimization model. The efficacy of this proposed hybrid approach is promising and can be applied as a powerful tool in designing a real supply chain network. It also provides the possibility to model and solve more realistic problems, which incorporate dynamism and uncertainty.
Energy Technology Data Exchange (ETDEWEB)
Guo, Y.; van Dam, J.; Bergua, R.; Jove, J.; Campbell, J.
2015-03-01
Nontorque loads induced by the wind turbine rotor overhang weight and aerodynamic forces can greatly affect drivetrain loads and responses. If not addressed properly, these loads can result in a decrease in gearbox component life. This work uses analytical modeling, computational modeling, and experimental data to evaluate a unique drivetrain design that minimizes the effects of nontorque loads on gearbox reliability: the Pure Torque(R) drivetrain developed by Alstom. The drivetrain has a hub-support configuration that transmits nontorque loads directly into the tower rather than through the gearbox as in other design approaches. An analytical model of Alstom's Pure Torque drivetrain provides insight into the relationships among turbine component weights, aerodynamic forces, and the resulting drivetrain loads. Main shaft bending loads are orders of magnitude lower than the rated torque and are hardly affected by wind conditions and turbine operations.
An analytic halo approach to the bispectrum of galaxies in redshift space
Yamamoto, Kazuhiro; Hikage, Chiaki
2016-01-01
We present an analytic formula for the galaxy bispectrum in redshift space on the basis of the halo approach description with the halo occupation distribution of central galaxies and satellite galaxies. This work is an extension of a previous work on the galaxy power spectrum, which illuminated the significant contribution of satellite galaxies to the higher multipole spectrum through the non-linear redshift space distortions of their random motions. Behaviors of the multipoles of the bispectrum are compared with results of numerical simulations assuming a halo occupation distribution of the LOWZ sample of the SDSS-III BOSS survey. Also presented are analytic approximate formulas for the multipoles of the bispectrum, which is useful to understanding their characteristic properties. We demonstrate that the Fingers of God effect is quite important for the higher multipoles of the bispectrum in redshift space, depending on the halo occupation distribution parameters.
Pan, Jun-Yang; Xie, Yi
2015-02-01
With tremendous advances in modern techniques, Einstein's general relativity has become an inevitable part of deep space missions. We investigate the relativistic algorithm for time transfer between the proper time τ of the onboard clock and the Geocentric Coordinate Time, which extends some previous works by including the effects of propagation of electromagnetic signals. In order to evaluate the implicit algebraic equations and integrals in the model, we take an analytic approach to work out their approximate values. This analytic model might be used in an onboard computer because of its limited capability to perform calculations. Taking an orbiter like Yinghuo-1 as an example, we find that the contributions of the Sun, the ground station and the spacecraft dominate the outcomes of the relativistic corrections to the model.
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Mosaffa Amirhossein
2013-01-01
Full Text Available Results are reported of an investigation of the solidification of a phase change material (PCM in a cylindrical shell thermal energy storage with radial internal fins. An approximate analytical solution is presented for two cases. In case 1, the inner wall is kept at a constant temperature and, in case 2, a constant heat flux is imposed on the inner wall. In both cases, the outer wall is insulated. The results are compared to those for a numerical approach based on an enthalpy method. The results show that the analytical model satisfactory estimates the solid-liquid interface. In addition, a comparative study is reported of the solidified fraction of encapsulated PCM for different geometric configurations of finned storage having the same volume and surface area of heat transfer.
Analytical Features: A Knowledge-Based Approach to Audio Feature Generation
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Pachet François
2009-01-01
Full Text Available We present a feature generation system designed to create audio features for supervised classification tasks. The main contribution to feature generation studies is the notion of analytical features (AFs, a construct designed to support the representation of knowledge about audio signal processing. We describe the most important aspects of AFs, in particular their dimensional type system, on which are based pattern-based random generators, heuristics, and rewriting rules. We show how AFs generalize or improve previous approaches used in feature generation. We report on several projects using AFs for difficult audio classification tasks, demonstrating their advantage over standard audio features. More generally, we propose analytical features as a paradigm to bring raw signals into the world of symbolic computation.
Design of thin-film photonic metamaterial L\\"uneburg lens using analytical approach
Gao, Hanhong; Johnson, Steven G; Barbastathis, George
2011-01-01
We design an all-dielectric L\\"uneburg lens as an adiabatic space-variant lattice explicitly accounting for finite film thickness. We describe an all-analytical approach to compensate for the finite height of subwavelength dielectric structures in the pass-band regime. This method calculates the effective refractive index of the infinite-height lattice from effective medium theory, then embeds a medium of the same effective index into a slab waveguide of finite height and uses the waveguide dispersion diagram to calculate a new effective index. The results are compared with the conventional numerical treatment - a direct band diagram calculation, using a modified three-dimensional lattice with the superstrate and substrate included in the cell geometry. We show that the analytical results are in good agreement with the numerical ones, and the performance of the thin-film L\\"uneburg lens is quite different than the estimates obtained assuming infinite height.
Lim, C. W.; Wu, B. S.; He, L. H.
2001-12-01
A novel approach is presented for obtaining approximate analytical expressions for the dispersion relation of periodic wavetrains in the nonlinear Klein-Gordon equation with even potential function. By coupling linearization of the governing equation with the method of harmonic balance, we establish two general analytical approximate formulas for the dispersion relation, which depends on the amplitude of the periodic wavetrain. These formulas are valid for small as well as large amplitude of the wavetrain. They are also applicable to the large amplitude regime, which the conventional perturbation method fails to provide any solution, of the nonlinear system under study. Three examples are demonstrated to illustrate the excellent approximate solutions of the proposed formulas with respect to the exact solutions of the dispersion relation. (c) 2001 American Institute of Physics.
Dynamic fault trees resolution: A conscious trade-off between analytical and simulative approaches
Energy Technology Data Exchange (ETDEWEB)
Chiacchio, F., E-mail: chiacchio@dmi.unict.it [Dipartimento di Matematica e Informatica-DMI, Universita degli Studi di Catania (Italy); Compagno, L., E-mail: lco@diim.unict.it [Dipartimento di Ingegneria Industriale e Meccanica-DIIM, Universita degli Studi di Catania (Italy); D' Urso, D., E-mail: ddurso@diim.unict.it [Dipartimento di Ingegneria Industriale e Meccanica-DIIM, Universita degli Studi di Catania (Italy); Manno, G., E-mail: gmanno@dmi.unict.it [Dipartimento di Matematica e Informatica-DMI, Universita degli Studi di Catania (Italy); Trapani, N., E-mail: ntrapani@diim.unict.it [Dipartimento di Ingegneria Industriale e Meccanica-DIIM, Universita degli Studi di Catania (Italy)
2011-11-15
Safety assessment in industrial plants with 'major hazards' requires a rigorous combination of both qualitative and quantitative techniques of RAMS. Quantitative assessment can be executed by static or dynamic tools of dependability but, while the former are not sufficient to model exhaustively time-dependent activities, the latter are still too complex to be used with success by the operators of the industrial field. In this paper we present a review of the procedures that can be used to solve quite general dynamic fault trees (DFT) that present a combination of the following characteristics: time dependencies, repeated events and generalized probability failure. Theoretical foundations of the DFT theory are discussed and the limits of the most known DFT tools are presented. Introducing the concept of weak and strong hierarchy, the well-known modular approach is adapted to study a more generic class of DFT. In order to quantify the approximations introduced, an ad-hoc simulative environment is used as benchmark. In the end, a DFT of an accidental scenario is analyzed with both analytical and simulative approaches. Final results are in good agreement and prove how it is possible to implement a suitable Monte Carlo simulation with the features of a spreadsheet environment, able to overcome the limits of the analytical tools, thus encouraging further researches along this direction. - Highlights: > Theoretical foundations of the DFT are reviewed and the limits of the analytical techniques are assessed. > Hierarchical technique is discussed, introducing the concepts of weak and strong equivalence. > Simulative environment developed with a spreadsheet electronic document is tested. > Comparison between the simulative and the analytical results is performed. > Classification of which technique is more suitable is provided, depending on the complexity of the DFT.
Factor Analysis of People Rather than Variables: Q and Other Two-Mode Factor Analytic Models.
Frederick, Brigitte N.
Factor analysis attempts to study how different objects group together to form factors with the purposes of: (1) reducing the number of factorable entities (e.g., variables) with which the researcher needs to deal; (2) searching data for qualitative and quantitative differences; and (3) testing hypotheses (R. Gorsuch, 1983). While most factor…
A UNIVERSAL ANALYTIC POTENTIAL-ENERGY FUNCTION BASED ON A PHASE FACTOR
Institute of Scientific and Technical Information of China (English)
C.F. Yu; K. Yan; D.Z. Liu
2006-01-01
Using a field equation with a phase factor, a universal analytic potential-energy function applied to the interactions between diatoms or molecules is derived, and five kinds of potential curves of common shapes are obtained adjusting the phase factors. The linear thermal expansion coefficients and Young's moduli of eleven kinds of fuce-centered cubic (fcc) metals - Al, Cu, Ag, etc. Are calculated using the potential-energy function; the computational results are quite consistent with experimental values. Moreover, an analytic relation between the linear thermal expansion coefficients and Young's moduli of fcc metals is given using the potential-energy function. Finally, the force constants of fifty-five kinds of diatomic moleculars with low excitation state are computed using this theory, and they are quite consistent with RKR (Rydberg-Klein-Rees) experimental values.
Analytic results for planar three-loop integrals for massive form factors
Henn, Johannes M.; Smirnov, Alexander V.; Smirnov, Vladimir A.
2016-12-01
We use the method of differential equations to analytically evaluate all planar three-loop Feynman integrals relevant for form factor calculations involving massive particles. Our results for ninety master integrals at general q 2 are expressed in terms of multiple polylogarithms, and results for fiftyone master integrals at the threshold q 2 = 4 m 2 are expressed in terms of multiple polylogarithms of argument one, with indices equal to zero or to a sixth root of unity.
Analytic results for planar three-loop integrals for massive form factors
Henn, Johannes M; Smirnov, Vladimir A
2016-01-01
We use the method of differential equations to analytically evaluate all planar three-loop Feynman integrals relevant for form factor calculations involving massive particles. Our results for ninety master integrals at general $q^2$ are expressed in terms of multiple polylogarithms, and results for fiftyone master integrals at the threshold $q^2=4m^2$ are expressed in terms of multiple polylogarithms of argument one, with indices equal to zero or to a sixth root of unity.
Flatland, Bente; Freeman, Kathy P; Friedrichs, Kristen R; Vap, Linda M; Getzy, Karen M; Evans, Ellen W; Harr, Kendal E
2010-09-01
Owing to lack of governmental regulation of veterinary laboratory performance, veterinarians ideally should demonstrate a commitment to self-monitoring and regulation of laboratory performance from within the profession. In response to member concerns about quality management in veterinary laboratories, the American Society for Veterinary Clinical Pathology (ASVCP) formed a Quality Assurance and Laboratory Standards (QAS) committee in 1996. This committee recently published updated and peer-reviewed Quality Assurance Guidelines on the ASVCP website. The Quality Assurance Guidelines are intended for use by veterinary diagnostic laboratories and veterinary research laboratories that are not covered by the US Food and Drug Administration Good Laboratory Practice standards (Code of Federal Regulations Title 21, Chapter 58). The guidelines have been divided into 3 reports on 1) general analytic factors for veterinary laboratory performance and comparisons, 2) hematology and hemostasis, and 3) clinical chemistry, endocrine assessment, and urinalysis. This report documents recommendations for control of general analytical factors within veterinary clinical laboratories and is based on section 2.1 (Analytical Factors Important In Veterinary Clinical Pathology, General) of the newly revised ASVCP QAS Guidelines. These guidelines are not intended to be all-inclusive; rather, they provide minimum guidelines for quality assurance and quality control for veterinary laboratory testing. It is hoped that these guidelines will provide a basis for laboratories to assess their current practices, determine areas for improvement, and guide continuing professional development and education efforts.
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Christopher J Millow
Full Text Available Persistent organic pollutants (POPs are typically monitored via targeted mass spectrometry, which potentially identifies only a fraction of the contaminants actually present in environmental samples. With new anthropogenic compounds continuously introduced to the environment, novel and proactive approaches that provide a comprehensive alternative to targeted methods are needed in order to more completely characterize the diversity of known and unknown compounds likely to cause adverse effects. Nontargeted mass spectrometry attempts to extensively screen for compounds, providing a feasible approach for identifying contaminants that warrant future monitoring. We employed a nontargeted analytical method using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOF-MS to characterize halogenated organic compounds (HOCs in California Black skimmer (Rynchops niger eggs. Our study identified 111 HOCs; 84 of these compounds were regularly detected via targeted approaches, while 27 were classified as typically unmonitored or unknown. Typically unmonitored compounds of note in bird eggs included tris(4-chlorophenylmethane (TCPM, tris(4-chlorophenylmethanol (TCPMOH, triclosan, permethrin, heptachloro-1'-methyl-1,2'-bipyrrole (MBP, as well as four halogenated unknown compounds that could not be identified through database searching or the literature. The presence of these compounds in Black skimmer eggs suggests they are persistent, bioaccumulative, potentially biomagnifying, and maternally transferring. Our results highlight the utility and importance of employing nontargeted analytical tools to assess true contaminant burdens in organisms, as well as to demonstrate the value in using environmental sentinels to proactively identify novel contaminants.
Analytical approach to the dynamics of facilitated spin models on random networks
Fennell, Peter G.; Gleeson, James P.; Cellai, Davide
2014-09-01
Facilitated spin models were introduced some decades ago to mimic systems characterized by a glass transition. Recent developments have shown that a class of facilitated spin models is also able to reproduce characteristic signatures of the structural relaxation properties of glass-forming liquids. While the equilibrium phase diagram of these models can be calculated analytically, the dynamics are usually investigated numerically. Here we propose a network-based approach, called approximate master equation (AME), to the dynamics of the Fredrickson-Andersen model. The approach correctly predicts the critical temperature at which the glass transition occurs. We also find excellent agreement between the theory and the numerical simulations for the transient regime, except in close proximity of the liquid-glass transition. Finally, we analytically characterize the critical clusters of the model and show that the departures between our AME approach and the Monte Carlo can be related to the large interface between blocked and unblocked spins at temperatures close to the glass transition.
Exploring Multi-Scale Spatiotemporal Twitter User Mobility Patterns with a Visual-Analytics Approach
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Junjun Yin
2016-10-01
Full Text Available Understanding human mobility patterns is of great importance for urban planning, traffic management, and even marketing campaign. However, the capability of capturing detailed human movements with fine-grained spatial and temporal granularity is still limited. In this study, we extracted high-resolution mobility data from a collection of over 1.3 billion geo-located Twitter messages. Regarding the concerns of infringement on individual privacy, such as the mobile phone call records with restricted access, the dataset is collected from publicly accessible Twitter data streams. In this paper, we employed a visual-analytics approach to studying multi-scale spatiotemporal Twitter user mobility patterns in the contiguous United States during the year 2014. Our approach included a scalable visual-analytics framework to deliver efficiency and scalability in filtering large volume of geo-located tweets, modeling and extracting Twitter user movements, generating space-time user trajectories, and summarizing multi-scale spatiotemporal user mobility patterns. We performed a set of statistical analysis to understand Twitter user mobility patterns across multi-level spatial scales and temporal ranges. In particular, Twitter user mobility patterns measured by the displacements and radius of gyrations of individuals revealed multi-scale or multi-modal Twitter user mobility patterns. By further studying such mobility patterns in different temporal ranges, we identified both consistency and seasonal fluctuations regarding the distance decay effects in the corresponding mobility patterns. At the same time, our approach provides a geo-visualization unit with an interactive 3D virtual globe web mapping interface for exploratory geo-visual analytics of the multi-level spatiotemporal Twitter user movements.
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Thomas M Kessler
Full Text Available BACKGROUND: Overactive bladder (OAB affects the lives of millions of people worldwide and antimuscarinics are the pharmacological treatment of choice. Meta-analyses of all currently used antimuscarinics for treating OAB found similar efficacy, making the choice dependent on their adverse event profiles. However, conventional meta-analyses often fail to quantify and compare adverse events across different drugs, dosages, formulations, and routes of administration. In addition, the assessment of the broad variety of adverse events is dissatisfying. Our aim was to compare adverse events of antimuscarinics using a network meta-analytic approach that overcomes shortcomings of conventional analyses. METHODS: Cochrane Incontinence Group Specialized Trials Register, previous systematic reviews, conference abstracts, book chapters, and reference lists of relevant articles were searched. Eligible studies included randomized controlled trials comparing at least one antimuscarinic for treating OAB with placebo or with another antimuscarinic, and adverse events as outcome measures. Two authors independently extracted data. A network meta-analytic approach was applied allowing for joint assessment of all adverse events of all currently used antimuscarinics while fully maintaining randomization. RESULTS: 69 trials enrolling 26'229 patients were included. Similar overall adverse event profiles were found for darifenacin, fesoterodine, transdermal oxybutynin, propiverine, solifenacin, tolterodine, and trospium chloride but not for oxybutynin orally administered when currently used starting dosages were compared. CONCLUSIONS: The proposed generally applicable transparent network meta-analytic approach summarizes adverse events in an easy to grasp way allowing straightforward benchmarking of antimuscarinics for treating OAB in clinical practice. Most currently used antimuscarinics seem to be equivalent first choice drugs to start the treatment of OAB except for
Kessler, Thomas M.; Bachmann, Lucas M.; Minder, Christoph; Löhrer, David; Umbehr, Martin; Schünemann, Holger J.; Kessels, Alfons G. H.
2011-01-01
Background Overactive bladder (OAB) affects the lives of millions of people worldwide and antimuscarinics are the pharmacological treatment of choice. Meta-analyses of all currently used antimuscarinics for treating OAB found similar efficacy, making the choice dependent on their adverse event profiles. However, conventional meta-analyses often fail to quantify and compare adverse events across different drugs, dosages, formulations, and routes of administration. In addition, the assessment of the broad variety of adverse events is dissatisfying. Our aim was to compare adverse events of antimuscarinics using a network meta-analytic approach that overcomes shortcomings of conventional analyses. Methods Cochrane Incontinence Group Specialized Trials Register, previous systematic reviews, conference abstracts, book chapters, and reference lists of relevant articles were searched. Eligible studies included randomized controlled trials comparing at least one antimuscarinic for treating OAB with placebo or with another antimuscarinic, and adverse events as outcome measures. Two authors independently extracted data. A network meta-analytic approach was applied allowing for joint assessment of all adverse events of all currently used antimuscarinics while fully maintaining randomization. Results 69 trials enrolling 26′229 patients were included. Similar overall adverse event profiles were found for darifenacin, fesoterodine, transdermal oxybutynin, propiverine, solifenacin, tolterodine, and trospium chloride but not for oxybutynin orally administered when currently used starting dosages were compared. Conclusions The proposed generally applicable transparent network meta-analytic approach summarizes adverse events in an easy to grasp way allowing straightforward benchmarking of antimuscarinics for treating OAB in clinical practice. Most currently used antimuscarinics seem to be equivalent first choice drugs to start the treatment of OAB except for oral oxybutynin dosages
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Javad Siahkali Moradi
2012-08-01
Full Text Available One of the most important issues affecting profitability is to determine the impact of different factors influencing purchasing activities. In this paper, we perform an extensive literature survey to detect different purchasing factors influencing customers' behavior. The factors are categorized in three different groups and they are ranked using analytical network process. The results of our survey indicate that three factors of personal, product and situational play important roles in purchasing impulse. The personal item includes different factors where demographic characteristic factors receive the highest ranking (35% followed by other factors are feelings, excitement and fun, self identify, education and novelty. There are also three sub-factors associated with demographic characteristics including gender, age and race and the weights are 0.46748, 0.42668 and 0.10584, respectively, which means gender is the most important factor followed by age and race. Finally, the other factor is associated with situational factors' group, which includes presence of others, culture, design of store, time available, local market condition, sales staff and self service with the relative importance of 0.04296, 0.08733, 0.12130, 0.22217, 0.05643, 0.15346 and 0.31635, respectively.
Birrell, Jane; Meares, Kevin; Wilkinson, Andrew; Freeston, Mark
2011-11-01
Since its emergence in the early 1990s, a narrow but concentrated body of research has developed examining the role of intolerance of uncertainty (IU) in worry, and yet we still know little about its phenomenology. In an attempt to clarify our understanding of this construct, this paper traces the way in which our understanding and definition of IU have evolved throughout the literature. This paper also aims to further our understanding of IU by exploring the latent variables measures by the Intolerance of Uncertainty Scale (IUS; Freeston, Rheaume, Letarte, Dugas & Ladouceur, 1994). A review of the literature surrounding IU confirmed that the current definitions are categorical and lack specificity. A critical review of existing factor analytic studies was carried out in order to determine the underlying factors measured by the IUS. Systematic searches yielded 9 papers for review. Two factors with 12 consistent items emerged throughout the exploratory studies, and the stability of models containing these two factors was demonstrated in subsequent confirmatory studies. It is proposed that these factors represent (i) desire for predictability and an active engagement in seeking certainty, and (ii) paralysis of cognition and action in the face of uncertainty. It is suggested that these factors may represent approach and avoidance responses to uncertainty. Further research is required to confirm the construct validity of these factors and to determine the stability of this structure within clinical samples.
Analytic network process (ANP approach for product mix planning in railway industry
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Hadi Pazoki Toroudi
2016-08-01
Full Text Available Given the competitive environment in the global market in recent years, organizations need to plan for increased profitability and optimize their performance. Planning for an appropriate product mix plays essential role for the success of most production units. This paper applies analytical network process (ANP approach for product mix planning for a part supplier in Iran. The proposed method uses four criteria including cost of production, sales figures, supply of raw materials and quality of products. In addition, the study proposes different set of products as alternatives for production planning. The preliminary results have indicated that that the proposed study of this paper could increase productivity, significantly.
Europe needs to take clear, analytical approach in considering future of nuclear energy
Energy Technology Data Exchange (ETDEWEB)
Shepherd, John [nuclear 24, Redditch (United Kingdom)
2016-11-15
Europe's political leaders have been accused of failing to offer a clear and comprehensive approach to the future of nuclear power in Europe. The criticism came in an opinion adopted recently by the European Economic and Social Committee (EESC). According to the EESC, the European Commission should propose ''a clear analytical process and methodology which can offer a consistent, voluntary framework for national decision-making about the role - if any - of nuclear power in the energy mix''.
An effective analytic approach for solving nonlinear fractional partial differential equations
Ma, Junchi; Zhang, Xiaolong; Liang, Songxin
2016-08-01
Nonlinear fractional differential equations are widely used for modelling problems in applied mathematics. A new analytic approach with two parameters c1 and c2 is first proposed for solving nonlinear fractional partial differential equations. These parameters are used to improve the accuracy of the resulting series approximations. It turns out that much more accurate series approximations are obtained by choosing proper values of c1 and c2. To demonstrate the applicability and effectiveness of the new method, two typical fractional partial differential equations, the nonlinear gas dynamics equation and the nonlinear KdV-Burgers equation, are solved.
AEROSTATIC AND AERODYNAMIC MODULES OF A HYBRID BUOYANT AIRCRAFT: AN ANALYTICAL APPROACH
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Anwar Ul Haque
2015-05-01
Full Text Available An analytical approach is essential for the estimation of the requirements of aerodynamic and aerostatic lift for a hybrid buoyant aircraft. Such aircrafts have two different modules to balance the weight of aircraft; aerostatic module and aerodynamic module. Both these modules are to be treated separately for estimation of the mass budget of propulsion systems and required power. In the present work, existing relationships of aircraft and airship are reviewed for its further application for these modules. Limitations of such relationships are also disussed and it is precieved that it will provide a strating point for better understanding of design anatomy of such aircraft.
Muñoz-Martínez, Amanda M; Coletti, Juan Pablo
2015-01-01
Abstract Functional Analytic Psychotherapy (FAP) is a therapeutic approach developed in context. FAP is characterized by use therapeutic relationship and the behaviors emit into it to improve clients daily life functioning. This therapeutic model is supported in behavior analysis principles and contextual functionalism philosophy. FAP proposes that clients behavior in session are functional equivalent with those out of session; therefore, when therapists respond to clients behaviors in session contingently, they promote and increase improvements in the natural setting. This article poses main features of FAP, its philosophical roots, achievements and research challenges to establish FAP as an independent treatment based on the evidence.
An analytical approach to space charge distortions for time projection chambers
Rossegger, S; Riegler, W
2010-01-01
In a time projection chamber (TPC), the possible ion feedback and also the primary ionization of high multiplicity events result in accumulation of ionic charges inside the gas volume (space charge). This charge introduces electrical field distortions and modifies the cluster trajectory along the drift path, affecting the tracking performance of the detector. In order to calculate the track distortions due to an arbitrary space charge distribution in the TPC, novel representations of the Green's function for a TPC geometry were worked out. This analytical approach finally permits accurate predictions of track distortions due to an arbitrary space charge distribution by solving the Langevin equation.
Dissociation activation barrier and heat of chemisorption: A morse-type analytical approach
Shustorovich, Evgeny M.
1985-02-01
The activation barrier Δ E∗ABfor dissociation AB → A + B on transition-metal surfaces is analyzed within an additive Morse-type approach based on the bond-order conservation. It is shown that Δ E∗AB = DAB-( QA + QB + QAQB/( QA + QB) where DAB is the gas-phase dissociation energy and Q A(Q B) is the heat of atomic chemisorption. Estimates of Δ E∗ for H 2, N 2, O 2, and NO are shown to be in reasonable agreement with experiment. The two-dimensional potential diagram of the metal-AB interactions is defined analytically and discussed in some detail.
Muñoz-Martínez, Amanda M; Coletti, Juan P
2015-01-01
Functional Analytic Psychotherapy (FAP) is a therapeutic approach developed in 'third wave therapies' context. FAP is characterized by use therapeutic relationship and the behaviors emit into it to improve clients daily life functioning. This therapeutic model is supported in behavior analysis principles and contextual functionalism philosophy. FAP proposes that clients behavior in session are functional equivalent with those out of session; therefore, when therapists respond to clients behaviors in session contingently, they promote and increase improvements in the natural setting. This article poses main features of FAP, its philosophical roots, achievements and research challenges to establish FAP as an independent treatment based on the evidence.
A combined analytic-numeric approach for some boundary-value problems
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Mustafa Turkyilmazoglu
2016-02-01
Full Text Available A combined analytic-numeric approach is undertaken in the present work for the solution of boundary-value problems in the finite or semi-infinite domains. Equations to be treated arise specifically from the boundary layer analysis of some two and three-dimensional flows in fluid mechanics. The purpose is to find quick but accurate enough solutions. Taylor expansions at either boundary conditions are computed which are next matched to the other asymptotic or exact boundary conditions. The technique is applied to the well-known Blasius as well as Karman flows. Solutions obtained in terms of series compare favorably with the existing ones in the literature.
Luo, Wei; Yin, Peifeng; Di, Qian; Hardisty, Frank; MacEachren, Alan M
2014-01-01
The world has become a complex set of geo-social systems interconnected by networks, including transportation networks, telecommunications, and the internet. Understanding the interactions between spatial and social relationships within such geo-social systems is a challenge. This research aims to address this challenge through the framework of geovisual analytics. We present the GeoSocialApp which implements traditional network analysis methods in the context of explicitly spatial and social representations. We then apply it to an exploration of international trade networks in terms of the complex interactions between spatial and social relationships. This exploration using the GeoSocialApp helps us develop a two-part hypothesis: international trade network clusters with structural equivalence are strongly 'balkanized' (fragmented) according to the geography of trading partners, and the geographical distance weighted by population within each network cluster has a positive relationship with the development level of countries. In addition to demonstrating the potential of visual analytics to provide insight concerning complex geo-social relationships at a global scale, the research also addresses the challenge of validating insights derived through interactive geovisual analytics. We develop two indicators to quantify the observed patterns, and then use a Monte-Carlo approach to support the hypothesis developed above.
Zhang, Xiaohua Douglas; Espeseth, Amy S; Johnson, Eric N; Chin, Jayne; Gates, Adam; Mitnaul, Lyndon J; Marine, Shane D; Tian, Jenny; Stec, Eric M; Kunapuli, Priya; Holder, Dan J; Heyse, Joseph F; Strulovici, Berta; Ferrer, Marc
2008-06-01
RNA interference (RNAi) not only plays an important role in drug discovery but can also be developed directly into drugs. RNAi high-throughput screening (HTS) biotechnology allows us to conduct genome-wide RNAi research. A central challenge in genome-wide RNAi research is to integrate both experimental and computational approaches to obtain high quality RNAi HTS assays. Based on our daily practice in RNAi HTS experiments, we propose the implementation of 3 experimental and analytic processes to improve the quality of data from RNAi HTS biotechnology: (1) select effective biological controls; (2) adopt appropriate plate designs to display and/or adjust for systematic errors of measurement; and (3) use effective analytic metrics to assess data quality. The applications in 5 real RNAi HTS experiments demonstrate the effectiveness of integrating these processes to improve data quality. Due to the effectiveness in improving data quality in RNAi HTS experiments, the methods and guidelines contained in the 3 experimental and analytic processes are likely to have broad utility in genome-wide RNAi research.
Combined analytical FEM approach for efficient simulation of Lamb wave damage detection.
Shen, Yanfeng; Giurgiutiu, Victor
2016-07-01
Lamb waves have been widely explored as a promising inspection tool for non-destructive evaluation (NDE) and structural health monitoring (SHM). This article presents a combined analytical finite element model (FEM) approach (CAFA) for the accurate, efficient, and versatile simulation of 2-D Lamb wave propagation and interaction with damage. CAFA used a global analytical solution to model wave generation, propagation, scattering, mode conversion, and detection, while the wave-damage interaction coefficients (WDICs) were extracted from harmonic analysis of local FEM with non-reflective boundaries (NRB). The analytical procedure was coded using MATLAB, and a predictive simulation tool called WaveFormRevealer 2-D was developed. The methodology of obtaining WDICs from local FEM was presented. Case studies were carried out for Lamb wave propagation in a pristine plate and a damaged plate. CAFA predictions compared well with full scale multi-physics FEM simulations and experiments with scanning laser Doppler vibrometry (SLDV), while achieving remarkable performance in computational efficiency and computer resource saving compared with conventional FEM.
Pinto, Eduardo Costa; Dolzan, Maressa Danielli; Cabral, Lucio Mendes; Armstrong, Daniel W; de Sousa, Valéria Pereira
2016-02-01
An important step during the development of high-performance liquid chromatography (HPLC) methods for quantitative analysis of drugs is choosing the appropriate detector. High sensitivity, reproducibility, stability, wide linear range, compatibility with gradient elution, non-destructive detection of the analyte and response unaffected by changes in the temperature/flow are some of the ideal characteristics of a universal HPLC detector. Topiramate is an anticonvulsant drug mainly used for the treatment of different types of seizures and prophylactic treatment of migraine. Different analytical approaches to quantify topiramate by HPLC have been described because of the lack of chromophoric moieties on its structure, such as derivatization with fluorescent moieties and UV-absorbing moieties, conductivity detection, evaporative light scattering detection, refractive index detection, chemiluminescent nitrogen detection and MS detection. Some methods for the determination of topiramate by capillary electrophoresis and gas chromatography have also been published. This systematic review provides a description of the main analytical methods presented in the literature to analyze topiramate in the drug substance and in pharmaceutical formulations. Each of these methods is briefly discussed, especially considering the detector used with HPLC. In addition, this article presents a review of the data available regarding topiramate stability, degradation products and impurities.
A Novel Analytical Approach to Pulsatile Blood Flow in the Arterial Network.
Flores, Joaquín; Alastruey, Jordi; Corvera Poiré, Eugenia
2016-10-01
Haemodynamic simulations using one-dimensional (1-D) computational models exhibit many of the features of the systemic circulation under normal and diseased conditions. We propose a novel linear 1-D dynamical theory of blood flow in networks of flexible vessels that is based on a generalized Darcy's model and for which a full analytical solution exists in frequency domain. We assess the accuracy of this formulation in a series of benchmark test cases for which computational 1-D and 3-D solutions are available. Accordingly, we calculate blood flow and pressure waves, and velocity profiles in the human common carotid artery, upper thoracic aorta, aortic bifurcation, and a 20-artery model of the aorta and its larger branches. Our analytical solution is in good agreement with the available solutions and reproduces the main features of pulse waveforms in networks of large arteries under normal physiological conditions. Our model reduces computational time and provides a new approach for studying arterial pulse wave mechanics; e.g., the analyticity of our model allows for a direct identification of the role played by physical properties of the cardiovascular system on the pressure waves.
Energy Technology Data Exchange (ETDEWEB)
Kumar, Sudhir [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CTCRS, Anushaktinagar, Mumbai 400094 (India); Srinivasan, P. [Radiation Safety Systems Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Sharma, S.D., E-mail: sdsharma_barc@rediffmail.com [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CTCRS, Anushaktinagar, Mumbai 400094 (India); Mayya, Y.S. [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CTCRS, Anushaktinagar, Mumbai 400094 (India)
2012-01-15
Measuring the strength of high dose rate (HDR) {sup 192}Ir brachytherapy sources on receipt from the vendor is an important component of a quality assurance program. Owing to their ready availability in radiotherapy departments, the Farmer-type ionization chambers are also used to determine the strength of HDR {sup 192}Ir brachytherapy sources. The use of a Farmer-type ionization chamber requires the estimation of the scatter correction factor along with positioning error (c) and the constant of proportionality (f) to determine the strength of HDR {sup 192}Ir brachytherapy sources. A simplified approach based on a least squares method was developed for estimating the values of f and M{sub s}. The seven distance method was followed to record the ionization chamber readings for parameterization of f and M{sub s}. Analytically calculated values of M{sub s} were used to determine the room scatter correction factor (K{sub sc}). The Monte Carlo simulations were also carried out to calculate f and K{sub sc} to verify the magnitude of the parameters determined by the proposed analytical approach. The value of f determined using the simplified analytical approach was found to be in excellent agreement with the Monte Carlo simulated value (within 0.7%). Analytically derived values of K{sub sc} were also found to be in good agreement with the Monte Carlo calculated values (within 1.47%). Being far simpler than the presently available methods of evaluating f, the proposed analytical approach can be adopted for routine use by clinical medical physicists to estimate f by hand calculations. - Highlights: Black-Right-Pointing-Pointer RAKR measurement of a brachytherapy source by 7 distance method requires the evaluation of 'f'. Black-Right-Pointing-Pointer A simplified analytical approach based on least square method to evaluate 'f' and 'M{sub s}' was developed. Black-Right-Pointing-Pointer Parameter 'f' calculated by proposed analytical
Analytical Structure Matching and Very Precise Approach to the Coulombic Quantum Three-Body Problem
Institute of Scientific and Technical Information of China (English)
TAN Shi-Na
2001-01-01
A powerful approach to solve the Coulombic quantum three-body problem is proposed. The approach is exponentially convergent and more efficient than the hypcrsphcrical coordinate method and the correlation-function hyperspherical harmonic method. This approach is numerically competitive with the variational methods, such as that using the Hylleraas-type basis functions. Numerical comparisons are made to demonstrate the efficiency of this approach, by calculating the nonrelativistic and infinite-nuclear-mass limit of the ground state energy of the helium atom. The exponential convergency of this approach is due to the full matching between the analytical structure of the basis functions that are used in this paper and the true wavefunction. This full matching was not reached by most other methods. For example, the variational method using the Hylleraas-type basis does not reflects the logarithmic singularity of the true wavefunction at the origin as predicted by Bartlett and Fock. Two important approaches are proposed in this work to reach this full matching: the coordinate transformation method and the asymptotic series method. Besides these, this work makes use of the lcast square method to substitute complicated numerical integrations in solving the Schrodinger equation without much loss of accuracy, which is routinely used by people to fit a theoretical curve with discrete experimental data, but here is used to simplify thc computation.``
Constraints on the $\\omega\\pi$ form factor from analyticity and unitarity
Ananthanarayan, B; Kubis, B
2014-01-01
Motivated by the discrepancies noted recently between the theoretical calculations of the electromagnetic $\\omega\\pi$ form factor and certain experimental data, we investigate this form factor using analyticity and unitarity in a framework known as the method of unitarity bounds. We use a QCD correlator computed on the spacelike axis by operator product expansion and perturbative QCD as input, and exploit the unitarity of its spectral function, including the two-pion contribution that can be reliably calculated using high-precision data on the pion form factor, as well as narrow isoscalar vector meson states. From this information, we derive upper and lower bounds on the modulus of the form factor in the elastic region. The results provide a significant check on those obtained with standard dispersion relations, confirming the existence of a disagreement with experimental data in the region around 0.6 GeV.
Ranking factors affecting the quality of banking services using analytic network process
Directory of Open Access Journals (Sweden)
Hooman Pourmohammad
2016-06-01
Full Text Available This paper seeks to identify the priority of factors affecting the quality of banking services in Bank Saderat Iran for better allocation of resources to enhance the quality of its banking services. The study develops a fuzzy method to handle uncertainty associated with the data and using analytical network process (ANP ranks different factors influencing on service quality. The results have indicated that the quality of e-services (ESQ is the most important factor followed by the quality of banking services agility (ASQ, the service system quality (SSQ, and the behavioral service qualities (BSQ. Moreover, the employees’ competence and skills, the reliability of the electronic system and the reliability of the service system, an impeccability banking system integrity and accountability instruments are among other effective factors influencing on the quality of banking services.
Alam, Muhammad Ashraful; Khan, M. Ryyan
2016-10-01
Bifacial tandem cells promise to reduce three fundamental losses (i.e., above-bandgap, below bandgap, and the uncollected light between panels) inherent in classical single junction photovoltaic (PV) systems. The successive filtering of light through the bandgap cascade and the requirement of current continuity make optimization of tandem cells difficult and accessible only to numerical solution through computer modeling. The challenge is even more complicated for bifacial design. In this paper, we use an elegantly simple analytical approach to show that the essential physics of optimization is intuitively obvious, and deeply insightful results can be obtained with a few lines of algebra. This powerful approach reproduces, as special cases, all of the known results of conventional and bifacial tandem cells and highlights the asymptotic efficiency gain of these technologies.
Analytical Approach to Predict Pre–Camber Deflection of the Pre-stressed Glulam Beams
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Anshari B.
2015-01-01
Full Text Available A new approach to reinforce glulam timber beams using compressed wood (CW has been developed by the Author. The compressed wood blocks are inserted into pre-cut holes on the top of glulam beams to produce pre-camber and to generate initial tensile and compressive stresses on the top and on the bottom extreme fiber of the glulam beam, respectively. A simple analytical approach has been developed to predict pre-camber deflections of the beams reinforced with three CW blocks. Assuming that moisture-dependent expansion of the CW block creates an interactive linear pressure between the glulam beam and the CW block, this would generate a pair of eccentric force away from the neutral axis of the beam. It is shown that the pre-camber deflection predicted at midspan of the short beams with various reinforcing arrangements give good agreement with the measured pre-camber from previous experimental results.
Energy Technology Data Exchange (ETDEWEB)
Tumelero, Fernanda; Petersen, Claudio Zen; Goncalves, Glenio Aguiar [Universidade Federal de Pelotas, Capao do Leao, RS (Brazil). Programa de Pos Graduacao em Modelagem Matematica; Schramm, Marcelo [Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica
2016-12-15
In this work, we report a solution to solve the Neutron Point Kinetics Equations applying the Polynomial Approach Method. The main idea is to expand the neutron density and delayed neutron precursors as a power series considering the reactivity as an arbitrary function of the time in a relatively short time interval around an ordinary point. In the first interval one applies the initial conditions and the analytical continuation is used to determine the solutions of the next intervals. A genuine error control is developed based on an analogy with the Rest Theorem. For illustration, we also report simulations for different approaches types (linear, quadratic and cubic). The results obtained by numerical simulations for linear approximation are compared with results in the literature.
Imaging MALDI MS of Dosed Brain Tissues Utilizing an Alternative Analyte Pre-extraction Approach
Quiason, Cristine M.; Shahidi-Latham, Sheerin K.
2015-06-01
Matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry has been adopted in the pharmaceutical industry as a useful tool to detect xenobiotic distribution within tissues. A unique sample preparation approach for MALDI imaging has been described here for the extraction and detection of cobimetinib and clozapine, which were previously undetectable in mouse and rat brain using a single matrix application step. Employing a combination of a buffer wash and a cyclohexane pre-extraction step prior to standard matrix application, the xenobiotics were successfully extracted and detected with an 8 to 20-fold gain in sensitivity. This alternative approach for sample preparation could serve as an advantageous option when encountering difficult to detect analytes.
Marino, Michele; Wriggers, Peter
2017-01-01
Composite materials reinforced by crimped fibers intervene in a number of advanced structural applications. Accordingly, constitutive equations describing their anisotropic behavior and explicitly accounting for fiber properties are needed for modeling and design purposes. To this aim, the finite strain response of crimped beams under uniaxial traction is herein addressed by obtaining analytical relationships based on the Principle of Virtual Works. The model is applied to collagen fibers in soft biological tissues, coupling geometric nonlinearities related to fiber crimp with material nonlinearities due to nanoscale mechanisms. Several numerical applications are presented, addressing the influence of geometric and material features. Available experimental data for tendons are reproduced, integrating the proposed approach within an optimization procedure for data fitting. The obtained results highlight the effectiveness of the proposed approach in correlating fibers structure with composite material mechanics.
Contaminant ingress into multizone buildings: An analytical state-space approach
DEFF Research Database (Denmark)
Parker, Simon; Coffey, Chris; Gravesen, Jens;
2014-01-01
-space approach is adopted to represent the concentration dynamics within multizone buildings. Analysis based on this approach is used to demonstrate that the exposure in every interior location is limited to the exterior exposure in the absence of removal mechanisms. Estimates are also developed for the short...... term maximum concentration and exposure in a multizone building in response to a step-change in concentration. These have considerable potential for practical use. The analytical development is demonstrated using a simple two-zone building with an inner zone and a range of existing multizone models...... of residential buildings. Quantitative measures are provided of the standard deviation of concentration and exposure within a range of residential multizone buildings. Ratios of the maximum short term concentrations and exposures to single zone building estimates are also provided for the same buildings....
Schumacher, Axel; Rujan, Tamas; Hoefkens, Jens
2014-12-01
The integration and analysis of large datasets in translational research has become an increasingly challenging problem. We propose a collaborative approach to integrate established data management platforms with existing analytical systems to fill the hole in the value chain between data collection and data exploitation. Our proposal in particular ensures data security and provides support for widely distributed teams of researchers. As a successful example for such an approach, we describe the implementation of a unified single platform that combines capabilities of the knowledge management platform tranSMART and the data analysis system Genedata Analyst™. The combined end-to-end platform helps to quickly find, enter, integrate, analyze, extract, and share patient- and drug-related data in the context of translational R&D projects.
Directory of Open Access Journals (Sweden)
Ghorbanali Rassam
2014-07-01
Full Text Available For the overall development of medicinal plants cultivation in Iran, there is a need to identify various effective factors on medicinal plant cultivation. A proper method for identifying the most effective factor on the development of the medicinal plants cultivation is essential. This research conducted in order to prioritizing of the effective criteria for the development of medicinal plant cultivation in North Khorasan province in Iran using Analytical Network Process (ANP method. The multi-criteria decision making (MCDM is suggested to be a viable method for factor selection and the analytic network process (ANP has been used as a tool for MCDM. For this purpose a list of effective factors offered to expert group. Then pair wise comparison questionnaires were distributed between relevant researchers and local producer experts of province to get their opinions about the priority of criteria and sub- criteria. The questionnaires were analyzed using Super Decision software. We illustrated the use of the ANP by ranking main effective factors such as economic, educational-extension services, cultural-social and supportive policies on development of medicinal plants. The main objective of the present study was to develop ANP as a decision making tool for prioritizing factors affecting the development of medicinal plants cultivation. Results showed that the ANP methodology was perfectly suited to tackling the complex interrelations involved in selection factor in this case. Also the results of the process revealed that among the factors, supporting the cultivation of medicinal plants, build the infrastructure for marketing support, having educated farmer and easy access to production input have most impact on the development of medicinal plant cultivation.
Sensitivity of the NMR density matrix to pulse sequence parameters: a simplified analytic approach.
Momot, Konstantin I; Takegoshi, K
2012-08-01
We present a formalism for the analysis of sensitivity of nuclear magnetic resonance pulse sequences to variations of pulse sequence parameters, such as radiofrequency pulses, gradient pulses or evolution delays. The formalism enables the calculation of compact, analytic expressions for the derivatives of the density matrix and the observed signal with respect to the parameters varied. The analysis is based on two constructs computed in the course of modified density-matrix simulations: the error interrogation operators and error commutators. The approach presented is consequently named the Error Commutator Formalism (ECF). It is used to evaluate the sensitivity of the density matrix to parameter variation based on the simulations carried out for the ideal parameters, obviating the need for finite-difference calculations of signal errors. The ECF analysis therefore carries a computational cost comparable to a single density-matrix or product-operator simulation. Its application is illustrated using a number of examples from basic NMR spectroscopy. We show that the strength of the ECF is its ability to provide analytic insights into the propagation of errors through pulse sequences and the behaviour of signal errors under phase cycling. Furthermore, the approach is algorithmic and easily amenable to implementation in the form of a programming code. It is envisaged that it could be incorporated into standard NMR product-operator simulation packages.
Thevis, Mario; Kuuranne, Tiia; Geyer, Hans; Schänzer, Wilhelm
2009-01-01
The list of prohibited substances and methods of doping issued by the World Anti-Doping Agency is updated and modified annually based on most recent developments and scientific data. Compounds and methods are maintained, added, or removed from the list, or they are placed in so-called monitoring programmes that have been established to obtain reliable data on the prevalence of particular substances and methods in- and/or out-of-competition. Consequently, doping control laboratories continuously update, modify and optimize existing screening and confirmation assays to ensure utmost comprehensiveness in detecting the prohibited and monitored substances as well as chemically and pharmacologically related analogs. The annual banned-substance review for human sports drug testing critically summarizes recent innovations in analytical approaches supporting the detection of established and newly outlawed substances and methods of doping. Literature from January 2007 through September 2008 as indexed in Medline and Web of Science was screened and articles on detection methods for substances and methods of doping in humans were compiled according to the 2008 Prohibited List of the World Anti-Doping Agency. Few new approaches were presented for individual doping agents and the majority of reports demonstrated new options for increasing the comprehensiveness of existing doping control assays. In addition, new techniques in separation and/or ionization of analytes complementary to commonly used procedures were described, which, so far, did not meet all requirements of sports drug testing. (c) 2009 John Wiley & Sons, Ltd.
Growth of tropical Dasyatid rays estimated using a multi-analytical approach.
Directory of Open Access Journals (Sweden)
Owen R O'Shea
Full Text Available We studied the age and growth of four sympatric stingrays: reticulate whipray, Himanutra uarnak (n=19; blue mask, Neotrygon kuhlii (n=34; cowtail, Pastinachus atrus (n=32 and blue-spotted fantail, Taeniura lymma (n=40 rays at Ningaloo Reef, a fringing coral reef on the north-western coast of western Australia. Age estimates derived from band counts within sectioned vertebrae ranged between 1 and 27 years (H. uarnak, 1 - 25 yrs.; N. kuhlii, 1.5 - 13 yrs.; P. atrus, 1 - 27 yrs. and T. lymma, 1 -11 yrs.. Due to limitations of sample sizes, we combined several analytical methods for estimating growth parameters. First, we used nonlinear least squares (NLS to identify the growth model that best fitted the data. We then used this model, prior information and the data within a Bayesian framework to approximate the posterior distribution of the growth parameters. For all species the two-parameter von Bertalanffy growth model provided the best fit to size-at-age datasets. Based on this model, the Bayesian approach allowed the estimation of median values of W(D∞ (cm and k (yr(-1 for the four species (H. uarnak: 149 and 0.12; N. kuhlii: 42 and 0.38; P. atrus 156 and 0.16, and T. lymma 33 and 0.24, respectively. Our approach highlights the value of combining different analytical methods and prior knowledge for estimating growth parameters when data quality and quantity are limited.
Fatehi, Shervin; Alguire, Ethan; Shao, Yihan; Subotnik, Joseph E
2011-12-21
We present a method for analytically calculating the derivative couplings between a pair of configuration-interaction-singles (CIS) excited states obtained in an atom-centered basis. Our theory is exact and has been derived using two completely independent approaches: one inspired by the Hellmann-Feynman theorem and the other following from direct differentiation. (The former is new, while the latter is in the spirit of existing approaches in the literature.) Our expression for the derivative couplings incorporates all Pulay effects associated with the use of an atom-centered basis, and the computational cost is minimal, roughly comparable to that of a single CIS energy gradient. We have validated our method against CIS finite-difference results and have applied it to the lowest lying excited states of naphthalene; we find that naphthalene derivative couplings include Pulay contributions sufficient to have a qualitative effect. Going beyond standard problems in analytic gradient theory, we have also constructed a correction, based on perturbative electron-translation factors, for including electronic momentum and eliminating spurious components of the derivative couplings that break translational symmetry. This correction is general and can be applied to any level of electronic structure theory.
Directory of Open Access Journals (Sweden)
Seretse Moyo
2011-03-01
Full Text Available Orientation: The Fifteen Factor Questionnaire Plus (15FQ+ is a prominent personality questionnaire that organisations frequently use in personnel selection in South Africa.Research purpose: The primary objective of this study was to undertake a factor analytic investigation of the first-order factor structure of the 15FQ+.Motivation for the study: The construct validity of the 15FQ+, as a measure of personality, is necessary even though it is insufficient to justify its use in personnel selection.Research design, approach and method: The researchers evaluated the fit of the measurement model, which the structure and scoring key of the 15FQ+ implies, in a quantitative study that used an ex post facto correlation design through structural equation modelling. They conducted a secondary data analysis. They selected a sample of 241 Black South African managers from a large 15FQ+ database.Main findings: The researchers found good measurement model fit. The measurement model parameter estimates were worrying. The magnitude of the estimated model parameters suggests that the items generally do not reflect the latent personality dimensions the designers intended them to with a great degree of precision. The items are reasonably noisy measures of the latent variables they represent.Practical/managerial implications: Organisations should use the 15FQ+ carefully on Black South African managers until further local research evidence becomes available.Contribution/value-add: The study is a catalyst to trigger the necessary additional research we need to establish convincingly the psychometric credentials of the 15FQ+ as a valuable assessment tool in South Africa.
Prevalence of risk factors for stuttering among boys: analytical cross-sectional study
Directory of Open Access Journals (Sweden)
Cristiane Moço Canhetti Oliveira
Full Text Available CONTEXT AND OBJECTIVE:There have been few studies on the risk factors for subgroups of stuttering. The aim of this study was to characterize the risk factors for developmental familial stuttering among boys who stutter and who do not stutter, such as disfluency types, associated quality and communication factors, emotional and physical stress, familial attitudes and personal reactions.DESIGN AND SETTING:Analytical cross-sectional study with a control group, performed at the Fluency Studies Laboratory of the Department of Speech and Hearing Disorders of a public university.METHODS: The parents of 40 age-matched stuttering and non-stuttering boys took part in this study. The participants were divided into two groups: stuttering children (SC and non-stuttering children (NSC, with ages between 6 years 0 months and 11 years 11 months. Initially, all of the participants underwent a fluency assessment and then data were gathered using the Protocol for the Risk of Developmental Stuttering.RESULTS:There were no differences in the physical stress distribution factors and personal reactions between the groups. Inappropriate familial attitudes were presented by 95% of the SC and 30% of the NSC. Four risk factors analyzed were not shown by the NSC, namely stuttering-like disfluency, quality factors, physical stress and emotional stresses.CONCLUSIONS:The findings suggest that the presence of stuttering-like disfluency, associated quality and communication factors, emotional stress and inappropriate family attitudes are important risk factors for familial developmental stuttering among boys.
Prevalence of risk factors for stuttering among boys: analytical cross-sectional study.
Oliveira, Cristiane Moço Canhetti; Nogueira, Paula Roberta
2014-01-01
There have been few studies on the risk factors for subgroups of stuttering. The aim of this study was to characterize the risk factors for developmental familial stuttering among boys who stutter and who do not stutter, such as disfluency types, associated quality and communication factors, emotional and physical stress, familial attitudes and personal reactions. Analytical cross-sectional study with a control group, performed at the Fluency Studies Laboratory of the Department of Speech and Hearing Disorders of a public university. The parents of 40 age-matched stuttering and non-stuttering boys took part in this study. The participants were divided into two groups: stuttering children (SC) and non-stuttering children (NSC), with ages between 6 years 0 months and 11 years 11 months. Initially, all of the participants underwent a fluency assessment and then data were gathered using the Protocol for the Risk of Developmental Stuttering. There were no differences in the physical stress distribution factors and personal reactions between the groups. Inappropriate familial attitudes were presented by 95% of the SC and 30% of the NSC. Four risk factors analyzed were not shown by the NSC, namely stuttering-like disfluency, quality factors, physical stress and emotional stresses. The findings suggest that the presence of stuttering-like disfluency, associated quality and communication factors, emotional stress and inappropriate family attitudes are important risk factors for familial developmental stuttering among boys.
Curtain, R
1997-01-01
This paper extends the coprime factorization approach to the synthesis of internally stabilizing controllers satisfying an H-infinity-norm bound to a class of systems with irrational transfer matrices. Using the coprime factorization description, the H-infinity-control problem can be reduced to two
Curtain, R
This paper extends the coprime factorization approach to the synthesis of internally stabilizing controllers satisfying an H-infinity-norm bound to a class of systems with irrational transfer matrices. Using the coprime factorization description, the H-infinity-control problem can be reduced to two
Approach of Decision Making Based on the Analytic Hierarchy Process for Urban Landscape Management
Srdjevic, Zorica; Lakicevic, Milena; Srdjevic, Bojan
2013-03-01
This paper proposes a two-stage group decision making approach to urban landscape management and planning supported by the analytic hierarchy process. The proposed approach combines an application of the consensus convergence model and the weighted geometric mean method. The application of the proposed approach is shown on a real urban landscape planning problem with a park-forest in Belgrade, Serbia. Decision makers were policy makers, i.e., representatives of several key national and municipal institutions, and experts coming from different scientific fields. As a result, the most suitable management plan from the set of plans is recognized. It includes both native vegetation renewal in degraded areas of park-forest and continued maintenance of its dominant tourism function. Decision makers included in this research consider the approach to be transparent and useful for addressing landscape management tasks. The central idea of this paper can be understood in a broader sense and easily applied to other decision making problems in various scientific fields.
Approach of decision making based on the analytic hierarchy process for urban landscape management.
Srdjevic, Zorica; Lakicevic, Milena; Srdjevic, Bojan
2013-03-01
This paper proposes a two-stage group decision making approach to urban landscape management and planning supported by the analytic hierarchy process. The proposed approach combines an application of the consensus convergence model and the weighted geometric mean method. The application of the proposed approach is shown on a real urban landscape planning problem with a park-forest in Belgrade, Serbia. Decision makers were policy makers, i.e., representatives of several key national and municipal institutions, and experts coming from different scientific fields. As a result, the most suitable management plan from the set of plans is recognized. It includes both native vegetation renewal in degraded areas of park-forest and continued maintenance of its dominant tourism function. Decision makers included in this research consider the approach to be transparent and useful for addressing landscape management tasks. The central idea of this paper can be understood in a broader sense and easily applied to other decision making problems in various scientific fields.
Maternal and infant activity: Analytic approaches for the study of circadian rhythm.
Thomas, Karen A; Burr, Robert L; Spieker, Susan
2015-11-01
The study of infant and mother circadian rhythm entails choice of instruments appropriate for use in the home environment as well as selection of analytic approach that characterizes circadian rhythm. While actigraphy monitoring suits the needs of home study, limited studies have examined mother and infant rhythm derived from actigraphy. Among this existing research a variety of analyses have been employed to characterize 24-h rhythm, reducing ability to evaluate and synthesize findings. Few studies have examined the correspondence of mother and infant circadian parameters for the most frequently cited approaches: cosinor, non-parametric circadian rhythm analysis (NPCRA), and autocorrelation function (ACF). The purpose of this research was to examine analytic approaches in the study of mother and infant circadian activity rhythm. Forty-three healthy mother and infant pairs were studied in the home environment over a 72h period at infant age 4, 8, and 12 weeks. Activity was recorded continuously using actigraphy monitors and mothers completed a diary. Parameters of circadian rhythm were generated from cosinor analysis, NPCRA, and ACF. The correlation among measures of rhythm center (cosinor mesor, NPCRA mid level), strength or fit of 24-h period (cosinor magnitude and R(2), NPCRA amplitude and relative amplitude (RA)), phase (cosinor acrophase, NPCRA M10 and L5 midpoint), and rhythm stability and variability (NPCRA interdaily stability (IS) and intradaily variability (IV), ACF) was assessed, and additionally the effect size (eta(2)) for change over time evaluated. Results suggest that cosinor analysis, NPCRA, and autocorrelation provide several comparable parameters of infant and maternal circadian rhythm center, fit, and phase. IS and IV were strongly correlated with the 24-h cycle fit. The circadian parameters analyzed offer separate insight into rhythm and differing effect size for the detection of change over time. Findings inform selection of analysis and
A Big Data and Learning Analytics Approach to Process-Level Feedback in Cognitive Simulations.
Pecaric, Martin; Boutis, Kathy; Beckstead, Jason; Pusic, Martin
2017-02-01
Collecting and analyzing large amounts of process data for the purposes of education can be considered a big data/learning analytics (BD/LA) approach to improving learning. However, in the education of health care professionals, the application of BD/LA is limited to date. The authors discuss the potential advantages of the BD/LA approach for the process of learning via cognitive simulations. Using the lens of a cognitive model of radiograph interpretation with four phases (orientation, searching/scanning, feature detection, and decision making), they reanalyzed process data from a cognitive simulation of pediatric ankle radiography where 46 practitioners from three expertise levels classified 234 cases online. To illustrate the big data component, they highlight the data available in a digital environment (time-stamped, click-level process data). Learning analytics were illustrated using algorithmic computer-enabled approaches to process-level feedback.For each phase, the authors were able to identify examples of potentially useful BD/LA measures. For orientation, the trackable behavior of re-reviewing the clinical history was associated with increased diagnostic accuracy. For searching/scanning, evidence of skipping views was associated with an increased false-negative rate. For feature detection, heat maps overlaid on the radiograph can provide a metacognitive visualization of common novice errors. For decision making, the measured influence of sequence effects can reflect susceptibility to bias, whereas computer-generated path maps can provide insights into learners' diagnostic strategies.In conclusion, the augmented collection and dynamic analysis of learning process data within a cognitive simulation can improve feedback and prompt more precise reflection on a novice clinician's skill development.
Directory of Open Access Journals (Sweden)
Johanna M Walz
Full Text Available Vascular endothelial growth factor-A (VEGF-A is intensively investigated in various medical fields. However, comparing VEGF-A measurements is difficult because sample acquisition and pre-analytic procedures differ between studies. We therefore investigated which variables act as confounders of VEGF-A measurements.Following a standardized protocol, blood was taken at three clinical sites from six healthy participants (one male and one female participant at each center twice one week apart. The following pre-analytical parameters were varied in order to analyze their impact on VEGF-A measurements: analyzing center, anticoagulant (EDTA vs. PECT / CTAD, cannula (butterfly vs. neonatal, type of centrifuge (swing-out vs. fixed-angle, time before and after centrifugation, filling level (completely filled vs. half-filled tubes and analyzing method (ELISA vs. multiplex bead array. Additionally, intrapersonal variations over time and sex differences were explored. Statistical analysis was performed using a linear regression model.The following parameters were identified as statistically significant independent confounders of VEGF-A measurements: analyzing center, anticoagulant, centrifuge, analyzing method and sex of the proband. The following parameters were no significant confounders in our data set: intrapersonal variation over one week, cannula, time before and after centrifugation and filling level of collection tubes.VEGF-A measurement results can be affected significantly by the identified pre-analytical parameters. We recommend the use of CTAD anticoagulant, a standardized type of centrifuge and one central laboratory using the same analyzing method for all samples.
An Approach for Routine Analytical Detection of Beeswax Adulteration Using FTIR-ATR Spectroscopy
Directory of Open Access Journals (Sweden)
Svečnjak Lidija
2015-12-01
Full Text Available Although beeswax adulteration represents one of the main beeswax quality issues, there are still no internationally standardised analytical methods for routine quality control. The objective of this study was to establish an analytical procedure suitable for routine detection of beeswax adulteration using FTIR-ATR spectroscopy. For the purpose of this study, reference IR spectra of virgin beeswax, paraffin, and their mixtures containing different proportions of paraffin (5 - 95%, were obtained. Mixtures were used for the establishment of calibration curves. To determine the prediction strength of IR spectral data for the share of paraffin in mixtures, the Partial Least Squares Regression method was used. The same procedure was conducted on beeswax-beef tallow mixtures. The model was validated using comb foundation samples of an unknown chemical background which had been collected from the international market (n = 56. Selected physico-chemical parameters were determined for comparison purposes. Results revealed a strong predictive power (R2 = 0.999 of IR spectra for the paraffin and beef tallow share in beeswax. The results also revealed that the majority of the analysed samples (89% were adulterated with paraffin; only 6 out of 56 (11% samples were identified as virgin beeswax, 28% of the samples exhibited a higher level of paraffin adulteration (>46% of paraffin, while the majority of the analysed samples (50% were found to be adulterated with 5 - 20% of paraffin. These results indicate an urgent need for routine beeswax authenticity control. In this study, we demonstrated that the analytical approach defining the standard curves for particular adulteration levels in beeswax, based on chemometric modelling of specific IR spectral region indicative for adulteration, enables reliable determination of the adulterant proportions in beeswax.
Kumar, Sudhir; Srinivasan, P; Sharma, S D; Mayya, Y S
2012-01-01
Measuring the strength of high dose rate (HDR) (192)Ir brachytherapy sources on receipt from the vendor is an important component of a quality assurance program. Owing to their ready availability in radiotherapy departments, the Farmer-type ionization chambers are also used to determine the strength of HDR (192)Ir brachytherapy sources. The use of a Farmer-type ionization chamber requires the estimation of the scatter correction factor along with positioning error (c) and the constant of proportionality (f) to determine the strength of HDR (192)Ir brachytherapy sources. A simplified approach based on a least squares method was developed for estimating the values of f and M(s). The seven distance method was followed to record the ionization chamber readings for parameterization of f and M(s). Analytically calculated values of M(s) were used to determine the room scatter correction factor (K(sc)). The Monte Carlo simulations were also carried out to calculate f and K(sc) to verify the magnitude of the parameters determined by the proposed analytical approach. The value of f determined using the simplified analytical approach was found to be in excellent agreement with the Monte Carlo simulated value (within 0.7%). Analytically derived values of K(sc) were also found to be in good agreement with the Monte Carlo calculated values (within 1.47%). Being far simpler than the presently available methods of evaluating f, the proposed analytical approach can be adopted for routine use by clinical medical physicists to estimate f by hand calculations.
A semi-analytic approach to angular momentum transport in stellar radiative interiors
Spada, F; Lanza, A F
2009-01-01
We address the problem of angular momentum transport in stellar radiative interiors with a novel semi-analytic spectral technique, using an eigenfunction series expansion, that can be used to derive benchmark solutions in hydromagnetic regimes with very high Reynolds number (10^7 - 10^8). The error arising from the truncation of the series is evaluated analytically. The main simplifying assumptions are the neglect of meridional circulation and of non-axisymmetric magnetic fields. The advantages of our approach are shown by applying it to a spin-down model for a 1 M_sun main-sequence star. The evolution of the coupling between core and envelope is investigated for different values of the viscosity and different geometries and values of the poloidal field. We confirm that a viscosity enhancement by 10^4 with respect to the molecular value is required to attain a rigid rotation in the core of the Sun within its present age. We suggest that a quadrupolar poloidal field may explain the short coupling time-scale ne...
Study of Gaussian and Bessel beam propagation using a new analytic approach
Dartora, C. A.; Nobrega, K. Z.
2012-03-01
The main feature of Bessel beams realized in practice is their ability to resist diffractive effects over distances exceeding the usual diffraction length. The theory and experimental demonstration of such waves can be traced back to the seminal work of Durnin and co-workers already in 1987. Despite that fact, to the best of our knowledge, the study of propagation of apertured Bessel beams found no solution in closed analytic form and it often leads to the numerical evaluation of diffraction integrals, which can be very awkward. In the context of paraxial optics, wave propagation in lossless media is described by an equation similar to the non-relativistic Schrödinger equation of quantum mechanics, but replacing the time t in quantum mechanics by the longitudinal coordinate z. Thus, the same mathematical methods can be employed in both cases. Using Bessel functions of the first kind as basis functions in a Hilbert space, here we present a new approach where it is possible to expand the optical wave field in a series, allowing to obtain analytic expressions for the propagation of any given initial field distribution. To demonstrate the robustness of the method two cases were taken into account: Gaussian and zeroth-order Bessel beam propagation.
Indian Academy of Sciences (India)
Pawan Kumar Gupta; Joy Kuri
2007-06-01
TCP performs poorly in wireless mobile networks due to large bit error rates. Basically, the TCP sender responds to these losses as if they were due to congestion in the network, and reduces the congestion window unnecessarily. In earlier work, it has been shown that adding a TCP header checksum is very useful in differentiating between congestion loss and corruption loss. With the modiﬁed TCP, receivers can explicitly indicate corruption of received packets by generating “Explicit Loss Notiﬁcations (ELNs).” This paper focuses on an analytical study of this modiﬁed TCP protocol. We derive an expression for the probability of a receiver generating successful ELN, assuming a generic link layer protocol for data transfer over wireless links. Next, we develop an analytical approach for TCP throughput evaluation under the modiﬁed scheme. We compare the throughput results obtained by analysis and simulation, and ﬁnd very close agreement between the two sets. We also compare the performance of the modiﬁed scheme with the standard NewReno TCP, and ﬁnd considerable improvement in data throughput over wireless links.
A Practical Approach Based on Analytic Deformable Algorithm for Scenic Image Registration.
Directory of Open Access Journals (Sweden)
Wei-Yen Hsu
Full Text Available Image registration is to produce an entire scene by aligning all the acquired image sequences. A registration algorithm is necessary to tolerance as much as possible for intensity and geometric variation among images. However, captured image views of real scene usually produce unexpected distortions. They are generally derived from the optic characteristics of image sensors or caused by the specific scenes and objects.An analytic registration algorithm considering the deformation is proposed for scenic image applications in this study. After extracting important features by the wavelet-based edge correlation method, an analytic registration approach is then proposed to achieve deformable and accurate matching of point sets. Finally, the registration accuracy is further refined to obtain subpixel precision by a feature-based Levenberg-Marquardt (FLM method. It converges evidently faster than most other methods because of its feature-based characteristic.We validate the performance of proposed method by testing with synthetic and real image sequences acquired by a hand-held digital still camera (DSC and in comparison with an optical flow-based motion technique in terms of the squared sum of intensity differences (SSD and correlation coefficient (CC. The results indicate that the proposed method is satisfactory in the registration accuracy and quality of DSC images.
Beam steering in superconducting quarter-wave resonators: An analytical approach
Directory of Open Access Journals (Sweden)
Alberto Facco
2011-07-01
Full Text Available Beam steering in superconducting quarter-wave resonators (QWRs, which is mainly caused by magnetic fields, has been pointed out in 2001 in an early work [A. Facco and V. Zviagintsev, in Proceedings of the Particle Accelerator Conference, Chicago, IL, 2001 (IEEE, New York, 2001, p. 1095], where an analytical formula describing it was proposed and the influence of cavity geometry was discussed. Since then, the importance of this effect was recognized and effective correction techniques have been found [P. N. Ostroumov and K. W. Shepard, Phys. Rev. ST Accel. Beams 4, 110101 (2001PRABFM1098-440210.1103/PhysRevSTAB.4.110101]. This phenomenon was further studied in the following years, mainly with numerical methods. In this paper we intend to go back to the original approach and, using well established approximations, derive a simple analytical expression for QWR steering which includes correction methods and reproduces the data starting from a few calculable geometrical constants which characterize every cavity. This expression, of the type of the Panofski equation, can be a useful tool in the design of superconducting quarter-wave resonators and in the definition of their limits of application with different beams.
Durante, Caterina; Baschieri, Carlo; Bertacchini, Lucia; Bertelli, Davide; Cocchi, Marina; Marchetti, Andrea; Manzini, Daniela; Papotti, Giulia; Sighinolfi, Simona
2015-04-15
Geographical origin and authenticity of food are topics of interest for both consumers and producers. Among the different indicators used for traceability studies, (87)Sr/(86)Sr isotopic ratio has provided excellent results. In this study, two analytical approaches for wine sample pre-treatment, microwave and low temperature mineralisation, were investigated to develop accurate and precise analytical method for (87)Sr/(86)Sr determination. The two procedures led to comparable results (paired t-test, with twine sample), processed during each sample batch (calculated Relative Standard Deviation, RSD%, equal to 0.002%. Lambrusco PDO (Protected Designation of Origin) wines coming from four different vintages (2009, 2010, 2011 and 2012) were pre-treated according to the best procedure and their isotopic values were compared with isotopic data coming from (i) soils of their territory of origin and (ii) wines obtained by same grape varieties cultivated in different districts. The obtained results have shown no significant variability among the different vintages of wines and a perfect agreement between the isotopic range of the soils and wines has been observed. Nevertheless, the investigated indicator was not enough powerful to discriminate between similar products. To this regard, it is worth to note that more soil samples as well as wines coming from different districts will be considered to obtain more trustworthy results.
Dąbrowska, Monika; Starek, Małgorzata
2014-01-01
l-Carnitine is a vitamin-like amino acid derivative, which is an essential factor in fatty acid metabolism as acyltransferase cofactor and in energy production processes, such as interconversion in the mechanisms of regulation of cetogenesis and termogenesis, and it is also used in the therapy of primary and secondary deficiency, and in other diseases. The determination of carnitine and acyl-carnitines can provide important information about inherited or acquired metabolic disorders, and for monitoring the biochemical effect of carnitine therapy. The endogenous carnitine pool in humans is maintained by biosynthesis and absorption of carnitine from the diet. Carnitine has one asymmetric carbon giving two stereoisomers d and l, but only the l form has a biological positive effect, thus chiral recognition of l-carnitine enantiomers is extremely important in biological, chemical and pharmaceutical sciences. In order to get more insight into carnitine metabolism and synthesis, a sensitive analysis for the determination of the concentration of free carnitine, carnitine esters and the carnitine precursors is required. Carnitine has been investigated in many biochemical, pharmacokinetic, metabolic and toxicokinetic studies and thus many analytical methods have been developed and published for the determination of carnitine in foods, dietary supplements, pharmaceutical formulations, biological tissues and body fluid. The analytical procedures presented in this review have been validated in terms of basic parameters (linearity, limit of detection, limit of quantitation, sensitivity, accuracy, and precision). This article presented the impact of different analytical techniques, and provides an overview of applications that address a diverse array of pharmaceutical and biological questions and samples. Copyright © 2013 Elsevier Ltd. All rights reserved.
Friedlander, Myrna L.; And Others
1985-01-01
Used a multidimensional content analysis to compare four expert counselors' approaches to family treatment. Two common change factors in family counseling were proposed: disruption of the existing balance of power among family members and education in the nature and strength of family systems. (JAC)
Friedlander, Myrna L.; And Others
1985-01-01
Used a multidimensional content analysis to compare four expert counselors' approaches to family treatment. Two common change factors in family counseling were proposed: disruption of the existing balance of power among family members and education in the nature and strength of family systems. (JAC)
Viswanathan, G M
2006-01-01
A challenging problem in physics concerns the possibility of forecasting rare but extreme phenomena such as large earthquakes, financial market crashes, and material rupture. A promising line of research involves the early detection of precursory log-periodic oscillations to help forecast extreme events in collective phenomena where discrete scale invariance plays an important role. Here I investigate two distinct approaches towards the general problem of how to detect log-periodic oscillations in arbitrary time series without prior knowledge of the location of the moveable singularity. I first show that the problem has a definite solution in Fourier space, however the technique involved requires an unrealistically large signal to noise ratio. I then show that the quadrature signal obtained via analytic continuation onto the imaginary axis, using the Hilbert transform, necessarily retains the log-periodicities found in the original signal. This finding allows the development of a new method of detecting log-p...
A New Approach to Analytic, Non-Perturbative and Gauge-Invariant QCD
Fried, H M; Sheu, Y -M
2012-01-01
Following a previous calculation of quark scattering in eikonal approximation, this paper presents a new, analytic and rigorous approach to the calculation of QCD phenomena. In this formulation a basic distinction between the conventional "idealistic" description of QCD and a more "realistic" description is brought into focus by a non-perturbative, gauge-invariant evaluation of the Schwinger solution for the QCD generating functional in terms of the exact Fradkin representations of the Green's functional and the vacuum functional. Because quarks exist asymptotically only in bound states, their transverse coordinates can never be measured with arbitrary precision; the non-perturbative neglect of this statement leads to obstructions that are easily corrected by invoking in the basic Lagrangian a probability amplitude which describes such transverse imprecision. The second result of this non-perturbative analysis is the appearance of a new and simplifying output called "Effective Locality", in which the interact...
Abidi, Syed Sibte Raza; Singh, Abhinav Kumar; Christie, Sean
2016-01-01
In this paper we present a framework for the semi-automatic extraction of medical entities from referral letters and use them to transcribe a case report form. Our framework offers the functionality to: (a) extract the medical entity from the unstructured referral letters, (b) classify them according to their semantic type, and (c) transcribe a case report form based on the extracted information from the referral letter. We take a semantic text analytics approach where SNOMED-CT ontology is used to both classify referral concepts and to establish semantic similarities between referral concepts and CRF elements. We used 100 spine injury referral letters, and a standard case report form used by Association of Dalhousie Neurosurgeons, Dalhousie University.
Oud, Bart; Maris, Antonius J A; Daran, Jean-Marc; Pronk, Jack T
2012-01-01
Successful reverse engineering of mutants that have been obtained by nontargeted strain improvement has long presented a major challenge in yeast biotechnology. This paper reviews the use of genome-wide approaches for analysis of Saccharomyces cerevisiae strains originating from evolutionary engineering or random mutagenesis. On the basis of an evaluation of the strengths and weaknesses of different methods, we conclude that for the initial identification of relevant genetic changes, whole genome sequencing is superior to other analytical techniques, such as transcriptome, metabolome, proteome, or array-based genome analysis. Key advantages of this technique over gene expression analysis include the independency of genome sequences on experimental context and the possibility to directly and precisely reproduce the identified changes in naive strains. The predictive value of genome-wide analysis of strains with industrially relevant characteristics can be further improved by classical genetics or simultaneous analysis of strains derived from parallel, independent strain improvement lineages. PMID:22152095
Esteve, Clara; D'Amato, Alfonsina; Marina, María Luisa; García, María Concepción; Righetti, Pier Giorgio
2013-10-30
Proteins in olive oil have been scarcely investigated probably due to the difficulty of working with such a lipidic matrix and the dramatically low abundance of proteins in this biological material. Additionally, this scarce information has generated contradictory results, thus requiring further investigations. This work treats this subject from a comprehensive point of view and proposes the use of different analytical approaches to delve into the characterization and identification of proteins in olive oil. Different extraction methodologies, including capture via combinational hexapeptide ligand libraries (CPLLs), were tried. A sequence of methodologies, starting with off-gel isoelectric focusing (IEF) followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) or high-performance liquid chromatography (HPLC) using an ultraperformance liquid chromatography (UPLC) column, was applied to profile proteins from olive seed, pulp, and oil. Besides this, and for the first time, a tentative identification of oil proteins by mass spectrometry has been attempted.
An Analytical Approach for Synthesizing Line Actuation Spaces of Parallel Flexure Mechanisms.
Yu, Jingjun; Li, Shouzhong; Qiu, Chen
2013-12-01
In this study, we present an analytical approach for synthesizing line actuation spaces of a parallel flexure mechanism (PFM) that can help designers to arrange linear actuators within the PFM in a correct and optimal way. On the basis of screw theory and upon an assumption of small deformations, an important synthesis criterion stated as "any actuation space of a flexure mechanism is always linearly independent of its constraint space" has been derived and disclosed for the first time. Guided by this criterion, a general synthesis process for the line actuation spaces of PFMs is introduced and demonstrated with several selective examples. The proposed synthesis criterion and process will enable designers to (i) systematically formulate line actuation spaces in the format of screw systems; (ii) likely yield a multiple solution to actuation spaces; and (iii) potentially determine an optimal result from those alternatives for actuator placement.
Casadio, Francesca; Douglas, Janet G; Faber, Katherine T
2007-02-01
This paper reports on an integrated analytical approach for the noninvasive characterization of Chinese nephrite samples, encompassing both geological reference specimens and museum objects. Natural variations induced by cationic substitutions, as well as human-induced alterations such as heating, which both affect color, are the focus of this contribution. Totally noninvasive methods of analysis were used, including X-ray fluorescence spectroscopy, Raman microspectroscopy, visible reflectance spectroscopy and X-ray diffraction; moreover, the feasibility of using a portable Raman spectrometer for the in-field identification of jades has been demonstrated. Fe/Fe+Mg (% p.f.u.) ratios of the jades have been calculated based on hydroxyl stretching Raman bands, which will provide an important addition to similar data that are being collected at major museums in the Western and Eastern hemispheres.
Free radicals in tobacco smoke – analytical approach and biomedical significanc
Directory of Open Access Journals (Sweden)
Leon Kośmider
2013-09-01
Full Text Available Free radicals, i.e. atoms or groups of atoms containing one or more unpaired electrons, are significant constituents of tobacco smoke that contribute to its toxic properties. Radicals are generated during complex pyrolysis and combustion reactions in burning a cigarette cone. It has been shown that some free radicals found in tobacco smoke have relatively long half-time life (over 5 mins. We have reviewed modern analytical methods used for identification and quantitative analysis of free radicals in tobacco smoke, particularly the electron paramagnetic resonance combined with a spin-trapping approach. We also discussed the role of free radicals in etiology of respiratory and cardiovascular conditions among smokers. Finally, we reviewed biochemical mechanisms of various pathological conditions, including disturbances in lipid peroxidation, activity modification of lecithin-cholesterol acyltransferase and level high density lipoprotein, hyperactivity to substance P, and inactivation of neutral endopeptidase, that are thought to be contributed by free radicals from tobacco smoke.
A Bayesian approach to the semi-analytic model of galaxy formation: methodology
Lu, Yu; Weinberg, Martin D; Katz, Neal S
2010-01-01
We believe that a wide range of physical processes conspire to shape the observed galaxy population but we remain unsure of their detailed interactions. The semi-analytic model (SAM) of galaxy formation uses multi-dimensional parameterizations of the physical processes of galaxy formation and provides a tool to constrain these underlying physical interactions. Because of the high dimensionality, the parametric problem of galaxy formation may be profitably tackled with a Bayesian-inference based approach, which allows one to constrain theory with data in a statistically rigorous way. In this paper, we develop a generalized SAM using the framework of Bayesian inference. We show that, with a parallel implementation of an advanced Markov-Chain Monte-Carlo algorithm, it is now possible to rigorously sample the posterior distribution of the high-dimensional parameter space of typical SAMs. As an example, we characterize galaxy formation in the current $\\Lambda$CDM cosmology using stellar mass function of galaxies a...
Battista, Natalia; Sergi, Manuel; Montesano, Camilla; Napoletano, Sabino; Compagnone, Dario; Maccarrone, Mauro
2014-01-01
Over the last two decades, the role played by phytocannabinoids and endocannabinoids in medicine has gained increasing interest in the scientific community. Upon identification of the plant compound Δ(9)-tetrahydrocannabinol (THC) and of the endogenous substance anandamide (AEA), different methodological approaches and innovative techniques have been developed, in order to evaluate the content of these molecules in various human matrices. In this review, we discuss the analytical methods that are currently used for the identification of phytocannabinoids and endocannabinoids, and we summarize the benefits and limitations of these procedures. Moreover, we provide an overview of the main biological matrices that have been analyzed to date for qualitative detection and quantitative determination of these compounds.
Analytical slave-spin mean-field approach to orbital selective Mott insulators
Komijani, Yashar; Kotliar, Gabriel
2017-09-01
We use the slave-spin mean-field approach to study particle-hole symmetric one- and two-band Hubbard models in the presence of Hund's coupling interaction. By analytical analysis of the Hamiltonian, we show that the locking of the two orbitals vs orbital selective Mott transition can be formulated within a Landau-Ginzburg framework. By applying the slave-spin mean field to impurity problems, we are able to make a correspondence between impurity and lattice. We also consider the stability of the orbital selective Mott phase to the hybridization between the orbitals and study the limitations of the slave-spin method for treating interorbital tunnelings in the case of multiorbital Bethe lattices with particle-hole symmetry.
Optimizing Photovoltaic Charge Generation of Nanowire Arrays: A Simple Semi-Analytic Approach
Sturmberg, Björn C P; Botten, Lindsay C; Asatryan, Ara A; Poulton, Christopher G; McPhedran, Ross C; de Sterke, C Martijn
2014-01-01
Nanowire arrays exhibit efficient light coupling and strong light trapping, making them well suited to solar cell applications. The processes that contribute to their absorption are interrelated and highly dispersive, so the only current method of optimizing the absorption is by intensive numerical calculations. We present an efficient alternative which depends solely on the wavelength-dependent refractive indices of the constituent materials. We choose each array parameter such that the number of modes propagating away from the absorber is minimized while the number of resonant modes within the absorber is maximized. From this we develop a semi-analytic method that quantitatively identifies the small range of parameters where arrays achieve maximum short circuit currents. This provides a fast route to optimizing NW array cell efficiencies by greatly reducing the geometries to study with full device models. Our approach is general and applies to a variety of materials and to a large range of array thicknesses...
Institute of Scientific and Technical Information of China (English)
Tianjiao; WEI; Yiru; WANG; Sen; HUANG
2013-01-01
From the perspective of students,the effectiveness of task-based approach in In-organic and Analytical Chemistry course were summarized.The strength and weak points of TBA were analyzed,and the specific suggestions for obtaining better effect were put forward.The result showed a satisfactory achievement and unexpected result in showing the effectiveness of this teaching model.Not only could this TBA enhance student’s overall knowledge of discipline but also cultivate students’ multi-dimensional competence:competence in searching literatures, communication and management,autonomous,co-operative and reflective learning,and competence in analyzing and problem-solving,as well as improving their language expression ability,and skills in using multi-media and internet technology into their academic course learning and research.The implication of this research on the classroom teaching practice will shed light on the future teaching reform of other courses in China.
ANALYTICAL APPROACH TO AERODYNAMIC CHARACTERISTICS OF THE HELICOPTER ROTOR WITH ANHEDRAL TIP SHAPE
Institute of Scientific and Technical Information of China (English)
1998-01-01
A new analytical approach, based on a lifting surface model and a full-span free wake analysis using the curved vortex element on the circular arc, is established for evaluating the aerodynamic characteristics of the helicopter rotor with an anhedral blade-tip and is emphasized to be applicable to various blade-tip configurations, such as the tapered, swept, anhedral and combined shapes. Sample calculations on the rotor aerodynamic characteristics for different anhedral tips in both hover and forward flight are performed. The results on the induced velocity, blade section lift distribution, tip vortex path and rotor performance are presented so that the effect of the anhedral tip on the rotor aerodynamic characteristics is fully analyzed.
Analytical approach to calculation of response spectra from seismological models of ground motion
Safak, Erdal
1988-01-01
An analytical approach to calculate response spectra from seismological models of ground motion is presented. Seismological models have three major advantages over empirical models: (1) they help in an understanding of the physics of earthquake mechanisms, (2) they can be used to predict ground motions for future earthquakes and (3) they can be extrapolated to cases where there are no data available. As shown with this study, these models also present a convenient form for the calculation of response spectra, by using the methods of random vibration theory, for a given magnitude and site conditions. The first part of the paper reviews the past models for ground motion description, and introduces the available seismological models. Then, the random vibration equations for the spectral response are presented. The nonstationarity, spectral bandwidth and the correlation of the peaks are considered in the calculation of the peak response.
Oud, Bart; van Maris, Antonius J A; Daran, Jean-Marc; Pronk, Jack T
2012-03-01
Successful reverse engineering of mutants that have been obtained by nontargeted strain improvement has long presented a major challenge in yeast biotechnology. This paper reviews the use of genome-wide approaches for analysis of Saccharomyces cerevisiae strains originating from evolutionary engineering or random mutagenesis. On the basis of an evaluation of the strengths and weaknesses of different methods, we conclude that for the initial identification of relevant genetic changes, whole genome sequencing is superior to other analytical techniques, such as transcriptome, metabolome, proteome, or array-based genome analysis. Key advantages of this technique over gene expression analysis include the independency of genome sequences on experimental context and the possibility to directly and precisely reproduce the identified changes in naive strains. The predictive value of genome-wide analysis of strains with industrially relevant characteristics can be further improved by classical genetics or simultaneous analysis of strains derived from parallel, independent strain improvement lineages.
Development of Analytical Approach to Evaluate (DiffServ-MIPv6 Scheme
Directory of Open Access Journals (Sweden)
Loay F. Hussien
2014-03-01
Full Text Available The aspiration of Mobile IPv6 is to provide uninterrupted network connectivity while the mobile node is moving between different access points or domains. Nonetheless, it does not provide QoS guaranteed to its users same as the traditional Internet protocol IP. It merely can provide Best-Effort (BE service to all its applications despite of the application requirements. The future wireless network would be based on IPv6 to provide services to Internet mobile users. Hence, one of main requirements of next generation IP based networks is providing QoS for real-time traffic that will be transporting through MIPv6 networks. This study presents the analytical analysis for the previously proposed scheme (DiffServ-MIPv6 that applies the DiffServ platform to Mobile IPv6 network in order to suit the needs of both QoS guaranteed and mobility in communication. The analytical evaluation is developed to assess the performance of the proposed scheme (DiffServ-MIPv6 compared to the standard MIPv6 protocol in terms of signaling cost. The signaling cost is measured against two factors session-to-mobility ratio and packet arrival rate.
Chung, Heeteak; Prado, Karl L; Yi, Byong Yong
2014-02-21
Phantom Scatter Factors, Sp in the Khan formalism (Khan et al 1980 J. Radiat. Oncol. Biol. Phys. 6 745-51) describe medium-induced changes in photon-beam intensity as a function of size of the beam. According to the British Journal of Radiology, Supplement 25, megavoltage phantom scatter factors are invariant as a function of photon-beam energy. However, during the commissioning of an accelerator with flattening filter free (FFF) photon beams (Varian TrueBeam(TM) 6-MV FFF and 10-MV FFF), differences were noted in phantom scatter between the filtered beams and FFF-mode beams. The purpose of this work was to evaluate this difference and provide an analytical formalism to explain the phantom scatter differences between FFF-mode and the filtered mode. An analytical formalism was devised to demonstrate the source of phantom scatter differences between the filtered and the FFF-mode beams. The reason for the differences in the phantom scatter factors between the filtered and the FFF-mode beams is hypothesized to be the non-uniform beam profiles of the FFF-mode beams. The analytical formalism proposed here is based on this idea, taking the product of the filtered phantom scatter factors and the ratio of the off-axis ratio between the FFF-mode and the filtered beams. All measurements were performed using a Varian TrueBeam(TM) linear accelerator with photon energies of 6-MV and 10-MV in both filtered and FFF-modes. For all measurements, a PTW Farmer type chamber and a Scanditronix CC04 cylindrical ionization were used. The in-water measurements were made at depth dose maximum and 100 cm source-to-axis distance. The in-air measurements were done at 100 cm source-to-axis distance with appropriate build-up cap. From these measurements, the phantom scatter factors were derived for the filtered beams and the FFF-mode beams for both energies to be evaluated against the phantoms scatter factors calculated using the proposed algorithm. For 6-MV, the difference between the measured
Directory of Open Access Journals (Sweden)
Ping Jiang
2015-01-01
Full Text Available Multidisciplinary design optimization (MDO has been applied widely in the design of complex engineering systems. To ease MDO problems, analytical target cascading (ATC organizes MDO process into multilevels according to the components of engineering systems, which provides a promising way to deal with MDO problems. ATC adopts a coordination strategy to coordinate the couplings between two adjacent levels in the design optimization process; however, existing coordination strategies in ATC face the obstacles of complicated coordination process and heavy computation cost. In order to conquer this problem, a quadratic exterior penalty function (QEPF based ATC (QEPF-ATC approach is proposed, where QEPF is adopted as the coordination strategy. Moreover, approximate models are adopted widely to replace the expensive simulation models in MDO; a QEPF-ATC and Kriging model combined approach is further proposed to deal with MDO problems, owing to the comprehensive performance, high approximation accuracy, and robustness of Kriging model. Finally, the geometric programming and reducer design cases are given to validate the applicability and efficiency of the proposed approach.
Almufti, R; Wilbaux, M; Oza, A; Henin, E; Freyer, G; Tod, M; Colomban, O; You, B
2014-01-01
Changes in serum tumor biomarkers may indicate treatment efficacy. Traditional tumor markers may soon be replaced by novel serum biomarkers, such as circulating tumor cells (CTCs) or circulating tumor nucleic acids. Given their promising predictive values, studies of their kinetics are warranted. Many methodologies meant to assess kinetics of traditional marker kinetics during anticancer treatment have been reported. Here, we review the methodologies, the advantages and the limitations of the analytical approaches reported in the literature. Strategies based on a single time point were first used (baseline value, normalization, nadir, threshold at a time t), followed by approaches based on two or more time points [half-life (HL), percentage decrease, time-to-events…]. Heterogeneities in methodologies and lack of consideration of inter- and intra-individual variability may account for the inconsistencies and the poor utility in routine. More recently, strategies based on a population kinetics approach and mathematical modeling have been reported. The identification of equations describing individual kinetic profiles of biomarkers may be an alternative strategy despite its complexity and higher number of necessary measurements. Validation studies are required. Efforts should be made to standardize biomarker kinetic analysis methodologies to ensure the optimized development of novel serum biomarkers and avoid the pitfalls of traditional markers.
Hubert, C; Houari, S; Rozet, E; Lebrun, P; Hubert, Ph
2015-05-22
When using an analytical method, defining an analytical target profile (ATP) focused on quantitative performance represents a key input, and this will drive the method development process. In this context, two case studies were selected in order to demonstrate the potential of a quality-by-design (QbD) strategy when applied to two specific phases of the method lifecycle: the pre-validation study and the validation step. The first case study focused on the improvement of a liquid chromatography (LC) coupled to mass spectrometry (MS) stability-indicating method by the means of the QbD concept. The design of experiments (DoE) conducted during the optimization step (i.e. determination of the qualitative design space (DS)) was performed a posteriori. Additional experiments were performed in order to simultaneously conduct the pre-validation study to assist in defining the DoE to be conducted during the formal validation step. This predicted protocol was compared to the one used during the formal validation. A second case study based on the LC/MS-MS determination of glucosamine and galactosamine in human plasma was considered in order to illustrate an innovative strategy allowing the QbD methodology to be incorporated during the validation phase. An operational space, defined by the qualitative DS, was considered during the validation process rather than a specific set of working conditions as conventionally performed. Results of all the validation parameters conventionally studied were compared to those obtained with this innovative approach for glucosamine and galactosamine. Using this strategy, qualitative and quantitative information were obtained. Consequently, an analyst using this approach would be able to select with great confidence several working conditions within the operational space rather than a given condition for the routine use of the method. This innovative strategy combines both a learning process and a thorough assessment of the risk involved.
Risk factor detection for heart disease by applying text analytics in electronic medical records.
Torii, Manabu; Fan, Jung-Wei; Yang, Wei-Li; Lee, Theodore; Wiley, Matthew T; Zisook, Daniel S; Huang, Yang
2015-12-01
In the United States, about 600,000 people die of heart disease every year. The annual cost of care services, medications, and lost productivity reportedly exceeds 108.9 billion dollars. Effective disease risk assessment is critical to prevention, care, and treatment planning. Recent advancements in text analytics have opened up new possibilities of using the rich information in electronic medical records (EMRs) to identify relevant risk factors. The 2014 i2b2/UTHealth Challenge brought together researchers and practitioners of clinical natural language processing (NLP) to tackle the identification of heart disease risk factors reported in EMRs. We participated in this track and developed an NLP system by leveraging existing tools and resources, both public and proprietary. Our system was a hybrid of several machine-learning and rule-based components. The system achieved an overall F1 score of 0.9185, with a recall of 0.9409 and a precision of 0.8972.
Analytical Solution for Model-Based Dynamic Power Factor Measurement in AC Resistance Spot Welding
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
On the basis of welding transformer circuit model, a new measuring method was proposed. This method measures the peak angle of the welding current, and then calculates the dynamic power factor in each half-wave.An artificial neural network is trained and used to generate simulation data for the analytical solution, i.e. a highorder binary polynomial, which can be easily adopted to calculate the power factor online. The tailored sensing and computing system ensures that the method possesses a real-time computational capacity and satisfying accuracy. A DSP-based resistance spot welding monitoring system was developed to perform ANN computation. The experimental results suggest that this measuring method is feasible.
Analysis of 10B by PIGE with factor analytical gamma-ray peak identification.
Savolainen, S; Räisänen, J; Eteläniemi, V; Abo Ramadan, U A; Kallio, M
1995-09-01
Studying the biodistribution of boronated compounds for B neutron capture therapy (BNCT) requires the accurate detection of low levels of boron (10B) in biological samples. Proton induced gamma-ray emission analysis (PIGE) of 10B was found to be viable in a study of low density lipoprotein (LDL), in tissue and blood samples. However, the method is sensitive to Na present in the samples and can therefore not be used for accurate measurements of 10B concentrations below 5 ppm in samples containing Na. PIGE can be considered to be an appropriate reference method for chemical B analysis. The factor analytical method presented here is the most objective way to separate Na and B peaks from each other, and the factorizing method can be applied in different forms of spectral analysis.
An analytical approach to evaluation of space radiation effects on materials for long-life missions
Moacanin, J.; Gupta, A.; Carroll, W. F.
1979-01-01
An analytical model was developed which quantifies effects on organic composite matrix materials of high energy electrons and of UV as well as interactions between the two radiations. Literature data on polyethylene were used to construct a degradation kinetics scheme corresponding to an Earth orbit at L=3. Analysis of the model showed that steady state concentrations of radicals put limits on accelerated test conditions. These conclusions were validated by an experimental study on polymethylmethacrylate using UV laser excitation. Relationships for balancing electron and UV radiations to equal acceleration factors are derived. Pulse radiolysis using an electron-beam along with time-resolved spectroscopy is shown to be able to separate primary form secondary reactions. Implications of these reactions to changes in engineering material properties are indicated. The use of mechanistic studies is discussed in the context of general test strategies for evaluating materials for space applications.
Han, Jie
2014-01-01
We investigate time-dependent probability for a Brownian particle passing over the barrier to stay at a metastable potential pocket against escaping over the barrier. This is related to whole fusion-fission dynamical process and can be called the reverse Kramers problem. By the passing probability over the saddle point of inverse harmonic potential multiplying the exponential decay factor of a particle in the metastable potential, we present an approximate expression for the modified passing probability over the barrier, in which the effect of reflection boundary of potential is taken into account. Our analytical result and Langevin Monte-Carlo simulation show that the probability passing and against escaping over the barrier is a non-monotonous function of time and its maximal value is less than the stationary result of passing probability over the saddle point of inverse harmonic potential.
A novel fast and accurate pseudo-analytical simulation approach for MOAO
Gendron, É.; Charara, A.; Abdelfattah, A.; Gratadour, D.; Keyes, D.; Ltaief, H.; Morel, C.; Vidal, F.; Sevin, A.; Rousset, G.
2014-08-01
Multi-object adaptive optics (MOAO) is a novel adaptive optics (AO) technique for wide-field multi-object spectrographs (MOS). MOAO aims at applying dedicated wavefront corrections to numerous separated tiny patches spread over a large field of view (FOV), limited only by that of the telescope. The control of each deformable mirror (DM) is done individually using a tomographic reconstruction of the phase based on measurements from a number of wavefront sensors (WFS) pointing at natural and artificial guide stars in the field. We have developed a novel hybrid, pseudo-analytical simulation scheme, somewhere in between the end-to- end and purely analytical approaches, that allows us to simulate in detail the tomographic problem as well as noise and aliasing with a high fidelity, and including fitting and bandwidth errors thanks to a Fourier-based code. Our tomographic approach is based on the computation of the minimum mean square error (MMSE) reconstructor, from which we derive numerically the covariance matrix of the tomographic error, including aliasing and propagated noise. We are then able to simulate the point-spread function (PSF) associated to this covariance matrix of the residuals, like in PSF reconstruction algorithms. The advantage of our approach is that we compute the same tomographic reconstructor that would be computed when operating the real instrument, so that our developments open the way for a future on-sky implementation of the tomographic control, plus the joint PSF and performance estimation. The main challenge resides in the computation of the tomographic reconstructor which involves the inversion of a large matrix (typically 40 000 × 40 000 elements). To perform this computation efficiently, we chose an optimized approach based on the use of GPUs as accelerators and using an optimized linear algebra library: MORSE providing a significant speedup against standard CPU oriented libraries such as Intel MKL. Because the covariance matrix is
A novel fast and accurate pseudo-analytical simulation approach for MOAO
Gendron, É.
2014-08-04
Multi-object adaptive optics (MOAO) is a novel adaptive optics (AO) technique for wide-field multi-object spectrographs (MOS). MOAO aims at applying dedicated wavefront corrections to numerous separated tiny patches spread over a large field of view (FOV), limited only by that of the telescope. The control of each deformable mirror (DM) is done individually using a tomographic reconstruction of the phase based on measurements from a number of wavefront sensors (WFS) pointing at natural and artificial guide stars in the field. We have developed a novel hybrid, pseudo-analytical simulation scheme, somewhere in between the end-to- end and purely analytical approaches, that allows us to simulate in detail the tomographic problem as well as noise and aliasing with a high fidelity, and including fitting and bandwidth errors thanks to a Fourier-based code. Our tomographic approach is based on the computation of the minimum mean square error (MMSE) reconstructor, from which we derive numerically the covariance matrix of the tomographic error, including aliasing and propagated noise. We are then able to simulate the point-spread function (PSF) associated to this covariance matrix of the residuals, like in PSF reconstruction algorithms. The advantage of our approach is that we compute the same tomographic reconstructor that would be computed when operating the real instrument, so that our developments open the way for a future on-sky implementation of the tomographic control, plus the joint PSF and performance estimation. The main challenge resides in the computation of the tomographic reconstructor which involves the inversion of a large matrix (typically 40 000 × 40 000 elements). To perform this computation efficiently, we chose an optimized approach based on the use of GPUs as accelerators and using an optimized linear algebra library: MORSE providing a significant speedup against standard CPU oriented libraries such as Intel MKL. Because the covariance matrix is
Yao, Yijun; Wu, Yun; Tang, Mengling; Wang, Yue; Wang, Jianjin; Suuberg, Eric M; Jiang, Lin; Liu, Jing
2015-11-15
In 2002, U.S. EPA proposed a general buffer zone of approximately 100 feet (30 m) laterally to determine which buildings to include in vapor intrusion (VI) investigations. However, this screening distance can be threatened by factors such as extensive surface pavements. Under such circumstances, EPA recommended investigating soil vapor migration distance on a site-specific basis. To serve this purpose, we present an analytical model (AAMLPH) as an alternative to estimate lateral VI screening distances at chlorinated compound-contaminated sites. Based on a previously introduced model (AAML), AAMLPH is developed by considering the effects of impervious surface cover and soil geology heterogeneities, providing predictions consistent with the three-dimensional (3-D) numerical simulated results. By employing risk-based and contribution-based screening levels of subslab concentrations (50 and 500 μg/m(3), respectively) and source-to-subslab attenuation factor (0.001 and 0.01, respectively), AAMLPH suggests that buildings greater than 30 m from a plume boundary can still be affected by VI in the presence of any two of the three factors, which are high source vapor concentration, shallow source and significant surface cover. This finding justifies the concern that EPA has expressed about the application of the 30 m lateral separation distance in the presence of physical barriers (e.g., asphalt covers or ice) at the ground surface.
Therapeutic approaches for tumor necrosis factor inhibition
Directory of Open Access Journals (Sweden)
Maria Letícia de Castro Barbosa
2011-09-01
Full Text Available Tumor necrosis factor (TNF consists of an inflammatory cytokine essential for homeostasis and organism defense. Despite its physiological relevance, both increased biosynthesis and release of TNF lead to the exacerbation of inflammatory and oxidative responses, which are related to the pathogenesis of a host of diseases of an inflammatory, autoimmune and/or infectious nature. In this context, effective therapeutic approaches for the modulation of TNF have been the focus of research efforts. Approximately one million individuals worldwide have been treated with biotechnological inhibitors of this cytokine, the so-called anti-TNF biopharmaceuticals. However, given the high risk of infection and the limitations related to cost and administration routes, new therapeutic approaches aimed at biological targets that directly or indirectly modulate the production and/or activation of TNF appear promising alternatives for the discovery of new anti-inflammatory and immunomodulatory orally active drugs and are therefore discussed in this paper.O fator de necrose tumoral (do inglês, tumor necrosis factor - TNF consiste em uma citocina inflamatória essencial para a homeostase e defesa do organismo. A despeito de sua relevância fisiológica, o aumento da biossíntese e liberação do TNF conduzem à exacerbação das respostas inflamatória e oxidativa, as quais estão relacionadas à patogênese de várias doenças de natureza inflamatória, auto-imune e/ou infecciosa. A busca por abordagens terapêuticas eficientes na modulação do TNF tem sido alvo de diversos esforços de pesquisa. Aproximadamente um milhão de pessoas ao redor do mundo já foi tratado com inibidores biotecnológicos desta citocina, os chamados biofármacos anti-TNF. Entretanto, em face ao elevado risco de infecções e as limitações relacionadas ao custo e a via de administração, novas abordagens terapêuticas com foco em alvos que modulem, de forma direta ou indireta, a produ
Analytical Assessment of Simultaneous Parallel Approach Feasibility from Total System Error
Madden, Michael M.
2014-01-01
In a simultaneous paired approach to closely-spaced parallel runways, a pair of aircraft flies in close proximity on parallel approach paths. The aircraft pair must maintain a longitudinal separation within a range that avoids wake encounters and, if one of the aircraft blunders, avoids collision. Wake avoidance defines the rear gate of the longitudinal separation. The lead aircraft generates a wake vortex that, with the aid of crosswinds, can travel laterally onto the path of the trail aircraft. As runway separation decreases, the wake has less distance to traverse to reach the path of the trail aircraft. The total system error of each aircraft further reduces this distance. The total system error is often modeled as a probability distribution function. Therefore, Monte-Carlo simulations are a favored tool for assessing a "safe" rear-gate. However, safety for paired approaches typically requires that a catastrophic wake encounter be a rare one-in-a-billion event during normal operation. Using a Monte-Carlo simulation to assert this event rarity with confidence requires a massive number of runs. Such large runs do not lend themselves to rapid turn-around during the early stages of investigation when the goal is to eliminate the infeasible regions of the solution space and to perform trades among the independent variables in the operational concept. One can employ statistical analysis using simplified models more efficiently to narrow the solution space and identify promising trades for more in-depth investigation using Monte-Carlo simulations. These simple, analytical models not only have to address the uncertainty of the total system error but also the uncertainty in navigation sources used to alert an abort of the procedure. This paper presents a method for integrating total system error, procedure abort rates, avionics failures, and surveillance errors into a statistical analysis that identifies the likely feasible runway separations for simultaneous paired
Contaminant ingress into multizone buildings: An analytical state-space approach
Parker, Simon
2013-08-13
The ingress of exterior contaminants into buildings is often assessed by treating the building interior as a single well-mixed space. Multizone modelling provides an alternative way of representing buildings that can estimate concentration time series in different internal locations. A state-space approach is adopted to represent the concentration dynamics within multizone buildings. Analysis based on this approach is used to demonstrate that the exposure in every interior location is limited to the exterior exposure in the absence of removal mechanisms. Estimates are also developed for the short term maximum concentration and exposure in a multizone building in response to a step-change in concentration. These have considerable potential for practical use. The analytical development is demonstrated using a simple two-zone building with an inner zone and a range of existing multizone models of residential buildings. Quantitative measures are provided of the standard deviation of concentration and exposure within a range of residential multizone buildings. Ratios of the maximum short term concentrations and exposures to single zone building estimates are also provided for the same buildings. © 2013 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.
An Analytical Approach for Fast Recovery of the LSI Properties in Magnetic Particle Imaging
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Hamed Jabbari Asl
2016-01-01
Full Text Available Linearity and shift invariance (LSI characteristics of magnetic particle imaging (MPI are important properties for quantitative medical diagnosis applications. The MPI image equations have been theoretically shown to exhibit LSI; however, in practice, the necessary filtering action removes the first harmonic information, which destroys the LSI characteristics. This lost information can be constant in the x-space reconstruction method. Available recovery algorithms, which are based on signal matching of multiple partial field of views (pFOVs, require much processing time and a priori information at the start of imaging. In this paper, a fast analytical recovery algorithm is proposed to restore the LSI properties of the x-space MPI images, representable as an image of discrete concentrations of magnetic material. The method utilizes the one-dimensional (1D x-space imaging kernel and properties of the image and lost image equations. The approach does not require overlapping of pFOVs, and its complexity depends only on a small-sized system of linear equations; therefore, it can reduce the processing time. Moreover, the algorithm only needs a priori information which can be obtained at one imaging process. Considering different particle distributions, several simulations are conducted, and results of 1D and 2D imaging demonstrate the effectiveness of the proposed approach.
A Hybrid Fuzzy Analytic Network Process Approach to the New Product Development Selection Problem
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Chiuh-Cheng Chyu
2014-01-01
Full Text Available New product development selection is a complex decision-making process. To uphold their competence in competitive business environments, enterprises are required to continuously introduce novel products into markets. This paper presents a fuzzy analytic network process (FANP for solving the product development selection problem. The fuzzy set theory is adopted to represent ambiguities and vagueness involved in each expert’s judgment. In the proposed model, the fuzzy Kano method and fuzzy DEMATEL are employed to filter criteria and establish interactions among the criteria, whereas the SAM is applied to aggregate experts’ opinions. Unlike the commonly used top-down relation-structuring approach, the proposed FANP first identifies the interdependence among the criteria and then the identified relationships are mapped to the clusters. This approach is more realistic, since the inner and outer relationships between criteria are simultaneously considered to establish the relationships among clusters. The proposed model is illustrated through a real life example, with a comparative analysis using modified TOPSIS and gray relation analysis in the synthesizing phase. The concluded results were approved by the case company. The proposed methodology not only is useful in the case study, but also can be generally applied in other similar decision situations.
A Deep Learning Approach to on-Node Sensor Data Analytics for Mobile or Wearable Devices.
Ravi, Daniele; Wong, Charence; Lo, Benny; Yang, Guang-Zhong
2017-01-01
The increasing popularity of wearable devices in recent years means that a diverse range of physiological and functional data can now be captured continuously for applications in sports, wellbeing, and healthcare. This wealth of information requires efficient methods of classification and analysis where deep learning is a promising technique for large-scale data analytics. While deep learning has been successful in implementations that utilize high-performance computing platforms, its use on low-power wearable devices is limited by resource constraints. In this paper, we propose a deep learning methodology, which combines features learned from inertial sensor data together with complementary information from a set of shallow features to enable accurate and real-time activity classification. The design of this combined method aims to overcome some of the limitations present in a typical deep learning framework where on-node computation is required. To optimize the proposed method for real-time on-node computation, spectral domain preprocessing is used before the data are passed onto the deep learning framework. The classification accuracy of our proposed deep learning approach is evaluated against state-of-the-art methods using both laboratory and real world activity datasets. Our results show the validity of the approach on different human activity datasets, outperforming other methods, including the two methods used within our combined pipeline. We also demonstrate that the computation times for the proposed method are consistent with the constraints of real-time on-node processing on smartphones and a wearable sensor platform.
A Visual Analytics Approach for Station-Based Air Quality Data
Directory of Open Access Journals (Sweden)
Yi Du
2016-12-01
Full Text Available With the deployment of multi-modality and large-scale sensor networks for monitoring air quality, we are now able to collect large and multi-dimensional spatio-temporal datasets. For these sensed data, we present a comprehensive visual analysis approach for air quality analysis. This approach integrates several visual methods, such as map-based views, calendar views, and trends views, to assist the analysis. Among those visual methods, map-based visual methods are used to display the locations of interest, and the calendar and the trends views are used to discover the linear and periodical patterns. The system also provides various interaction tools to combine the map-based visualization, trends view, calendar view and multi-dimensional view. In addition, we propose a self-adaptive calendar-based controller that can flexibly adapt the changes of data size and granularity in trends view. Such a visual analytics system would facilitate big-data analysis in real applications, especially for decision making support.
A Visual Analytics Approach for Station-Based Air Quality Data.
Du, Yi; Ma, Cuixia; Wu, Chao; Xu, Xiaowei; Guo, Yike; Zhou, Yuanchun; Li, Jianhui
2016-12-24
With the deployment of multi-modality and large-scale sensor networks for monitoring air quality, we are now able to collect large and multi-dimensional spatio-temporal datasets. For these sensed data, we present a comprehensive visual analysis approach for air quality analysis. This approach integrates several visual methods, such as map-based views, calendar views, and trends views, to assist the analysis. Among those visual methods, map-based visual methods are used to display the locations of interest, and the calendar and the trends views are used to discover the linear and periodical patterns. The system also provides various interaction tools to combine the map-based visualization, trends view, calendar view and multi-dimensional view. In addition, we propose a self-adaptive calendar-based controller that can flexibly adapt the changes of data size and granularity in trends view. Such a visual analytics system would facilitate big-data analysis in real applications, especially for decision making support.
Gravity field error analysis for pendulum formations by a semi-analytical approach
Li, Huishu; Reubelt, Tilo; Antoni, Markus; Sneeuw, Nico
2017-03-01
Many geoscience disciplines push for ever higher requirements on accuracy, homogeneity and time- and space-resolution of the Earth's gravity field. Apart from better instruments or new observables, alternative satellite formations could improve the signal and error structure compared to Grace. One possibility to increase the sensitivity and isotropy by adding cross-track information is a pair of satellites flying in a pendulum formation. This formation contains two satellites which have different ascending nodes and arguments of latitude, but have the same orbital height and inclination. In this study, the semi-analytical approach for efficient pre-mission error assessment is presented, and the transfer coefficients of range, range-rate and range-acceleration gravitational perturbations are derived analytically for the pendulum formation considering a set of opening angles. The new challenge is the time variations of the opening angle and the range, leading to temporally variable transfer coefficients. This is solved by Fourier expansion of the sine/cosine of the opening angle and the central angle. The transfer coefficients are further applied to assess the error patterns which are caused by different orbital parameters. The simulation results indicate that a significant improvement in accuracy and isotropy is obtained for small and medium initial opening angles of single polar pendulums, compared to Grace. The optimal initial opening angles are 45° and 15° for accuracy and isotropy, respectively. For a Bender configuration, which is constituted by a polar Grace and an inclined pendulum in this paper, the behaviour of results is dependent on the inclination (prograde vs. retrograde) and on the relative baseline orientation (left or right leading). The simulation for a sun-synchronous orbit shows better results for the left leading case.
Gravity field error analysis for pendulum formations by a semi-analytical approach
Li, Huishu; Reubelt, Tilo; Antoni, Markus; Sneeuw, Nico
2016-10-01
Many geoscience disciplines push for ever higher requirements on accuracy, homogeneity and time- and space-resolution of the Earth's gravity field. Apart from better instruments or new observables, alternative satellite formations could improve the signal and error structure compared to uc(Grace). One possibility to increase the sensitivity and isotropy by adding cross-track information is a pair of satellites flying in a pendulum formation. This formation contains two satellites which have different ascending nodes and arguments of latitude, but have the same orbital height and inclination. In this study, the semi-analytical approach for efficient pre-mission error assessment is presented, and the transfer coefficients of range, range-rate and range-acceleration gravitational perturbations are derived analytically for the pendulum formation considering a set of opening angles. The new challenge is the time variations of the opening angle and the range, leading to temporally variable transfer coefficients. This is solved by Fourier expansion of the sine/cosine of the opening angle and the central angle. The transfer coefficients are further applied to assess the error patterns which are caused by different orbital parameters. The simulation results indicate that a significant improvement in accuracy and isotropy is obtained for small and medium initial opening angles of single polar pendulums, compared to uc(Grace). The optimal initial opening angles are 45° and 15° for accuracy and isotropy, respectively. For a Bender configuration, which is constituted by a polar uc(Grace) and an inclined pendulum in this paper, the behaviour of results is dependent on the inclination (prograde vs. retrograde) and on the relative baseline orientation (left or right leading). The simulation for a sun-synchronous orbit shows better results for the left leading case.
Maglaveras, Nicos; Kilintzis, Vassilis; Koutkias, Vassilis; Chouvarda, Ioanna
2016-01-01
Integrated care and connected health are two fast evolving concepts that have the potential to leverage personalised health. From the one side, the restructuring of care models and implementation of new systems and integrated care programs providing coaching and advanced intervention possibilities, enable medical decision support and personalized healthcare services. From the other side, the connected health ecosystem builds the means to follow and support citizens via personal health systems in their everyday activities and, thus, give rise to an unprecedented wealth of data. These approaches are leading to the deluge of complex data, as well as in new types of interactions with and among users of the healthcare ecosystem. The main challenges refer to the data layer, the information layer, and the output of information processing and analytics. In all the above mentioned layers, the primary concern is the quality both in data and information, thus, increasing the need for filtering mechanisms. Especially in the data layer, the big biodata management and analytics ecosystem is evolving, telemonitoring is a step forward for data quality leverage, with numerous challenges still left to address, partly due to the large number of micro-nano sensors and technologies available today, as well as the heterogeneity in the users' background and data sources. This leads to new R&D pathways as it concerns biomedical information processing and management, as well as to the design of new intelligent decision support systems (DSS) and interventions for patients. In this paper, we illustrate these issues through exemplar research targeting chronic patients, illustrating the current status and trends in PHS within the integrated care and connected care world.
Effective factors on optimizing banks’ balance sheet using fuzzy analytical hierarchy process
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Shoja Rezaei
2013-11-01
Full Text Available Every bank seeks methods to optimize its assets and liabilities, thus the main subject is managing assets-liabilities in the balance sheet and the main question is by which factor banks will be enabled to have an optimized combination of assets and liabilities in a common level of risk to get the most return. This case study is dedicated to Refah bank and is an applicable study. The data has collected from the headquarter by a questionnaire and finally effective factors weight on optimizing bank balance sheet determined by using Fuzzy analytical hierarchy process. Results showed that revenue has more effect on optimizing for %39.5 and also loan to deposit ratio for %.74, regarding revenue as a symbol of efficiency in banks, it seems to be the most important factor and goal in banking industry. Furthermore banks need to have some liquidity to respond customers demand to cover one of the most important risks of banking. This factor importance determined to be %18 in Refah Bank by using model and experts view.
Directory of Open Access Journals (Sweden)
Mousavi
2016-02-01
Full Text Available Background Cardiovascular Disease (CVD is developing treacherously along industrialization and development of urbanization Objectives The aim of this study was to compare cardiovascular risk factors between subjects with and without diabetes mellitus in the Minoodar district of Qazvin. Patients and Methods This analytical study was conducted on 100 subjects with diabetes and 140 subjects without diabetes in Qazvin from September 2010 to April 2011. Standardized measurements were available for waist circumference (WC, blood pressure (BP, fasting serum cholesterol, high-density lipoprotein cholesterol (HDL, and triglycerides (TGs. Cardiovascular risk factors were defined according to the diagnostic criteria proposed by the national cholesterol education program. Data were analyzed using the t-test, Mann-Whitney U test, and Chi-square test. Results Overall, 12% of subjects with diabetes and 17.9% of subjects without diabetes were smokers (P = 0.277. The WC, TGs, systolic and diastolic BP were significantly higher in subjects with diabetes compared to subjects without diabetes. The prevalence of high WC, high BP, low HDL, and high TGs were significantly higher in subjects with diabetes compared to subjects without diabetes. Conclusions Cardiovascular risk factors were higher in subjects with diabetes compared to subjects without diabetes. Lifestyle intervention programs should be focused on community education about reduction of CVD risk factors in patients with diabetes.
Exploration of Simple Analytical Approaches for Rapid Detection of Pathogenic Bacteria
Energy Technology Data Exchange (ETDEWEB)
Rahman, Salma [Iowa State Univ., Ames, IA (United States)
2005-01-01
Many of the current methods for pathogenic bacterial detection require long sample-preparation and analysis time, as well as complex instrumentation. This dissertation explores simple analytical approaches (e.g., flow cytometry and diffuse reflectance spectroscopy) that may be applied towards ideal requirements of a microbial detection system, through method and instrumentation development, and by the creation and characterization of immunosensing platforms. This dissertation is organized into six sections. In the general Introduction section a literature review on several of the key aspects of this work is presented. First, different approaches for detection of pathogenic bacteria will be reviewed, with a comparison of the relative strengths and weaknesses of each approach, A general overview regarding diffuse reflectance spectroscopy is then presented. Next, the structure and function of self-assembled monolayers (SAMs) formed from organosulfur molecules at gold and micrometer and sub-micrometer patterning of biomolecules using SAMs will be discussed. This section is followed by four research chapters, presented as separate manuscripts. Chapter 1 describes the efforts and challenges towards the creation of imunosensing platforms that exploit the flexibility and structural stability of SAMs of thiols at gold. 1H, 1H, 2H, 2H-perfluorodecyl-1-thiol SAM (PFDT) and dithio-bis(succinimidyl propionate)-(DSP)-derived SAMs were used to construct the platform. Chapter 2 describes the characterization of the PFDT- and DSP-derived SAMs, and the architectures formed when it is coupled to antibodies as well as target bacteria. These studies used infrared reflection spectroscopy (IRS), X-ray photoelectron spectroscopy (XPS), and electrochemical quartz crystal microbalance (EQCM), Chapter 3 presents a new sensitive, and portable diffuse reflection based technique for the rapid identification and quantification of pathogenic bacteria. Chapter 4 reports research efforts in the
Drury, Colin G
2015-01-01
In recent years, advances in sensor technology, connectedness and computational power have come together to produce huge data-sets. The treatment and analysis of these data-sets is known as big data analytics (BDA), and the somewhat related term data mining. Fields allied to human factors/ergonomics (HFE), e.g. statistics, have developed computational methods to derive meaningful, actionable conclusions from these data bases. This paper examines BDA, often characterised by volume, velocity and variety, giving examples of successful BDA use. This examination provides context by considering examples of using BDA on human data, using BDA in HFE studies, and studies of how people perform BDA. Significant issues for HFE are the reliance of BDA on correlation rather than hypotheses and theory, the ethics of BDA and the use of HFE in data visualisation.
Mougeot, X
2016-03-01
From a review of the available literature, a database of experimental shape factors from measured beta spectra was created in previous work. Classical assumptions applied in beta spectra calculations which avoid the determination of the electron and nuclear wave functions were tested by comparison with each measured spectrum present in the database. From this systematic comparison, it was demonstrated that the typical assumption λk=1 is inappropriate for all forbidden unique transitions. Moreover, the equally common ξ-approximation was also proved to be incorrect for about half of the listed first forbidden non-unique transitions and for all second non-unique ones. In present work, this study has been performed once again using an improved analytical screening correction. General results from previous study still remain the same. Except for allowed transitions, the mean energies in current nuclear databases are expected to be erroneous. Some selected beta spectra are also given to illustrate these results.
Energy Technology Data Exchange (ETDEWEB)
Morini, Filippo; Deleuze, Michael S., E-mail: michael.deleuze@uhasselt.be [Center of Molecular and Materials Modelling, Hasselt University, Agoralaan Gebouw D, B-3590 Diepenbeek (Belgium); Watanabe, Noboru; Takahashi, Masahiko [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan)
2015-03-07
The influence of thermally induced nuclear dynamics (molecular vibrations) in the initial electronic ground state on the valence orbital momentum profiles of furan has been theoretically investigated using two different approaches. The first of these approaches employs the principles of Born-Oppenheimer molecular dynamics, whereas the so-called harmonic analytical quantum mechanical approach resorts to an analytical decomposition of contributions arising from quantized harmonic vibrational eigenstates. In spite of their intrinsic differences, the two approaches enable consistent insights into the electron momentum distributions inferred from new measurements employing electron momentum spectroscopy and an electron impact energy of 1.2 keV. Both approaches point out in particular an appreciable influence of a few specific molecular vibrations of A{sub 1} symmetry on the 9a{sub 1} momentum profile, which can be unravelled from considerations on the symmetry characteristics of orbitals and their energy spacing.
Hanson, Jordan C
2016-01-01
The Askaryan effect describes coherent electromagnetic radiation from the collective charge within high-energy cascades in dense media. We present the first fully analytic model of Askaryan radiation that accounts simultaneously for the three-dimensional form factor of the electromagnetic cascade and the Landau-Pomeranchuk-Migdal (LPM) effect. Analytic calculations avoid computationally intensive Monte Carlo simulations of the cascades. Searches for cosmogenic neutrinos in Askaryan- based detectors benefit from computational speed, because neutrino event parameters affect the shape of the electromagnetic field, requiring scans of parameter space. The Askaryan field is derived and verified against Geant4 simulations, and compared with prior numerical and semi-analytic calculations. Finally, two special cases of the model are transformed from the Fourier domain to the time-domain, analytically. Next-generation in situ detectors like ARA and ARIANNA can use analytic time-domain signal models to search for phase ...
All-coupling polaron optical response: Analytic approaches beyond the adiabatic approximation
Klimin, S. N.; Tempere, J.; Devreese, J. T.
2016-09-01
In the present work, the problem of an all-coupling analytic description for the optical conductivity of the Fröhlich polaron is treated, with the goal being to bridge the gap in the validity range that exists between two complementary methods: on the one hand, the memory-function formalism and, on the other hand, the strong-coupling expansion based on the Franck-Condon picture for the polaron response. At intermediate coupling, both methods were found to fail as they do not reproduce diagrammatic quantum Monte Carlo results. To resolve this, we modify the memory-function formalism with respect to the Feynman-Hellwarth-Iddings-Platzman approach in order to take into account a nonquadratic interaction in a model system for the polaron. The strong-coupling expansion is extended beyond the adiabatic approximation by including in the treatment nonadiabatic transitions between excited polaron states. The polaron optical conductivity that we obtain at T =0 by combining the two extended methods agrees well, both qualitatively and quantitatively, with the diagrammatic quantum Monte Carlo results in the whole available range of the electron-phonon coupling strength.
Schmidt, Catherine M; Walton, Marc S; Trentelman, Karen
2009-10-15
Many of the Raman spectra obtained from areas painted with ultramarine pigments in illuminated manuscript leaves from the 14th century Italian manuscript the Laudario of Sant'Agnese, in the collection of the J. Paul Getty Museum, also contain strong bands not typically associated with this pigment. The source of these features was investigated using a multitechnique analytical approach. Techniques employed include Raman microspectroscopy, scanning electron microscopy with energy-dispersive spectroscopy, electron probe microanalysis, and laser ablation inductively coupled plasma mass spectrometry. The results indicate the presence of diopside (CaMgSi(2)O(6)), a mineral commonly associated with lapis lazuli in nature, and suggest that transition metal dopants in the diopside may be responsible for the Raman features, likely the result of fluorescence with vibronic coupling. The implication of this result with respect to using Raman spectroscopy as a fast, noninvasive, and nondestructive method for determining the geological provenance of natural lapis lazuli pigments used in art is discussed.
A Bayesian approach to the semi-analytic model of galaxy formation: methodology
Lu, Yu; Mo, H. J.; Weinberg, Martin D.; Katz, Neal
2011-09-01
We believe that a wide range of physical processes conspire to shape the observed galaxy population, but we remain unsure of their detailed interactions. The semi-analytic model (SAM) of galaxy formation uses multidimensional parametrizations of the physical processes of galaxy formation and provides a tool to constrain these underlying physical interactions. Because of the high dimensionality, the parametric problem of galaxy formation may be profitably tackled with a Bayesian-inference-based approach, which allows one to constrain theory with data in a statistically rigorous way. In this paper, we develop a SAM in the framework of Bayesian inference. We show that, with a parallel implementation of an advanced Markov chain Monte Carlo algorithm, it is now possible to rigorously sample the posterior distribution of the high-dimensional parameter space of typical SAMs. As an example, we characterize galaxy formation in the current Λ cold dark matter cosmology using the stellar mass function of galaxies as an observational constraint. We find that the posterior probability distribution is both topologically complex and degenerate in some important model parameters, suggesting that thorough explorations of the parameter space are needed to understand the models. We also demonstrate that because of the model degeneracy, adopting a narrow prior strongly restricts the model. Therefore, the inferences based on SAMs are conditional to the model adopted. Using synthetic data to mimic systematic errors in the stellar mass function, we demonstrate that an accurate observational error model is essential to meaningful inference.
An analytic approach to 2D electronic PE spectra of molecular systems
Energy Technology Data Exchange (ETDEWEB)
Szoecs, V., E-mail: szocs@fns.uniba.sk [Institute of Chemistry, Comenius University, Mlynska dolina CH2, 842 15 Bratislava (Slovakia)
2011-05-26
Graphical abstract: The three-pulse photon echo (3P-PE) spectra of finite molecular systems using direct calculation from electronic Hamiltonians allows peak classification from 3P-PE spectra dynamics. Display Omitted Highlights: {yields} RWA approach to electronic photon echo. {yields} A straightforward calculation of 2D electronic spectrograms in finite molecular systems. {yields} Importance of population time dynamics in relation to inter-site coherent coupling. - Abstract: The three-pulse photon echo (3P-PE) spectra of finite molecular systems and simplified line broadening models is presented. The Fourier picture of a heterodyne detected three-pulse rephasing PE signal in the {delta}-pulse limit of the external field is derived in analytic form. The method includes contributions of one and two-excitonic states and allows direct calculation of Fourier PE spectrogram from corresponding Hamiltonian. As an illustration, the proposed treatment is applied to simple systems, e.g. 2-site two-level system (TLS) and n-site TLS model of photosynthetic unit. The importance of relation between Fourier picture of 3P-PE dynamics (corresponding to nonzero population time, T) and coherent inter-state coupling is emphasized.
Canevali, Carmen; Gentile, Paolo; Orlandi, Marco; Modugno, Francesca; Lucejko, Jeannette Jacqueline; Colombini, Maria Perla; Brambilla, Laura; Goidanich, Sara; Riedo, Chiara; Chiantore, Oscar; Baraldi, Pietro; Baraldi, Cecilia; Gamberini, Maria Cristina
2011-10-01
Nine black powders found in Pompeii houses in three different types of bronze vessels (cylindrical theca atramentaria, unguentaries, and aryballoi) were characterized in order to assess a correspondence between the composition and the type of vessel and, possibly, to verify if these powders were inks or not. For the compositional characterization, a multi-analytical approach was adopted, which involved the use of scanning electron microscopy-energy dispersive X-ray, Fourier-transformed infrared spectroscopy, Raman, X-ray diffraction, electron paramagnetic resonance spectroscopy, thermogravimetric analysis, gas chromatography coupled with mass spectrometry (GC/MS), and pyrolysis GC/MS. Powders contained in cylindrical theca atramentaria form a homogeneous group, and their organic and inorganic compositions suggest that they were writing inks, while powders contained in unguentaries and aryballoi could have had several different uses, including writing inks and cosmetics. Furthermore, the composition profile of the powders found in cylindrical cases shows that, at 79 AD: , in Pompeii, carbon-based inks were still used for writing, and iron gall inks had not been introduced yet.
Shigayeva, Altynay; Coker, Richard J
2015-04-01
There is renewed concern over the sustainability of disease control programmes, and re-emergence of policy recommendations to integrate programmes with general health systems. However, the conceptualization of this issue has remarkably received little critical attention. Additionally, the study of programmatic sustainability presents methodological challenges. In this article, we propose a conceptual framework to support analyses of sustainability of communicable disease programmes. Through this work, we also aim to clarify a link between notions of integration and sustainability. As a part of development of the conceptual framework, we conducted a systematic literature review of peer-reviewed literature on concepts, definitions, analytical approaches and empirical studies on sustainability in health systems. Identified conceptual proposals for analysis of sustainability in health systems lack an explicit conceptualization of what a health system is. Drawing upon theoretical concepts originating in sustainability sciences and our review here, we conceptualize a communicable disease programme as a component of a health system which is viewed as a complex adaptive system. We propose five programmatic characteristics that may explain a potential for sustainability: leadership, capacity, interactions (notions of integration), flexibility/adaptability and performance. Though integration of elements of a programme with other system components is important, its role in sustainability is context specific and difficult to predict. The proposed framework might serve as a basis for further empirical evaluations in understanding complex interplay between programmes and broader health systems in the development of sustainable responses to communicable diseases.
Offshore drilling effects in Brazilian SE marine sediments: a meta-analytical approach.
Dore, Marina Pereira; Farias, Cássia; Hamacher, Cláudia
2017-01-01
The exploration and production of oil and gas reserves often result to drill cutting accumulations on the seafloor adjacent to drill locations. In this study, the detection of drilling influence on marine sediments was performed by meta-analytical comparison between data from pre- and post-drilling surveys undertaken in offshore Campos Basin, southeast of Brazil. Besides this overall appraisal on the geochemical variables, a multivariate assessment, considering only the post-drilling data, was performed. Among the variables, fines content, carbonates, total organic carbon, barium, chromium, copper, iron, manganese, nickel, lead, vanadium, zinc, and total petroleum hydrocarbons, only barium, copper, and hydrocarbons were related to drilling impacts. In relation to the point of discharge, relative elevated levels in the post-drilling campaigns were observed preferentially up to 500 m in the northeast and southwest directions, associated to the Brazil Current-predominant direction. Other distributed concentrations in the surroundings seem to indicate the dilution and dispersion of drilling waste promoted by meteoceanographic factors.
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Hemant Bamoriya
2012-12-01
Full Text Available The Indian Pharma market is highly fragmented & nature of competition is intense. Further, in modern times influencing doctors’ prescription decision has become very complex as there is little systematic knowledge about factors affecting the doctors’ prescription behaviour and the weight of individual factor. This study aims to demystify this complex prescription behaviour of doctors, through examining the above mentioned factors. For this purpose, a focus group study will be followed by a quantitative study using the Analytic Hierarchy Process (AHP approach. The findings of the study will have important implications for the marketers in order to do proper allocation of their resources, to improve their promotional efficiency.
DEFF Research Database (Denmark)
Thanki, Shashank; Govindan, Kannan; Thakkar, Jitesh
2016-01-01
the positive impact of integrated lean and green paradigms on a firm's performance and competitiveness. This paper applies an analytical hierarchy process approach to investigate the impact of select lean and green practices on performance benefits, and to evaluate the influence of lean and green paradigms...
López-García, Jeanett; Jiménez Zamudio, Jorge Javier
2017-01-01
It is very common to find in contemporary literature of Differential Equations, the need to incorporate holistically in teaching and learning the three different approaches: analytical, qualitative, and numerical, for continuous dynamical systems. However, nowadays, in some Bachelor of Science that includes only one course in differential…
D.L. Roorda; H.M.Y. Koomen; J.L. Spilt; F.J. Oort
2010-01-01
A meta-analytic approach was used to investigate the associations between affective qualities of teacher-student relationships (TSRs) and students’ school engagement and achievement. Results were based on 99 studies, including students from preschool to high school. Separate analyses were conducted
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Marc Lochbaum
2015-06-01
Conclusion: The performance goal contrast holds value for sport performance research. Contrary to approach-avoidance predictions, the mastery-approach goal and performance effect size was significant and of equal magnitude as the performance approach goal and performance effect size. Thus, future research should closely test the efficacy of both the mastery- and performance contrasts in impacting performance of sport tasks. Last, the significant effect sizes reported in this review are in stark contrast to contemporary meta-analytic findings in education. Differences in the approach-avoidance goals in sport and education relative to performance should be researched further.
A Semi-Analytical Approach for the Response of Nonlinear Conservative Systems
DEFF Research Database (Denmark)
Kimiaeifar, Amin; Barari, Amin; Fooladi, M;
2011-01-01
This work applies Parameter expanding method (PEM) as a powerful analytical technique in order to obtain the exact solution of nonlinear problems in the classical dynamics. Lagrange method is employed to derive the governing equations. The nonlinear governing equations are solved analytically by ...... that this method is an effective and convenient tool for solving these types of problems....
An Analytic Approach to Projectile Motion in a Linear Resisting Medium
Stewart, Sean M.
2006-01-01
The time of flight, range and the angle which maximizes the range of a projectile in a linear resisting medium are expressed in analytic form in terms of the recently defined Lambert W function. From the closed-form solutions a number of results characteristic to the motion of the projectile in a linear resisting medium are analytically confirmed,…
Analytical Psychology: A Review of a Theoretical Approach and Its Application to Counseling.
Ziff, Katherine K.
Analytical psychology is a field supported by training centers, specially trained analysts, and a growing body of literature. While it receives much recognition, it remains mostly outside the mainstream of counseling and counselor education. This document presents a brief history of analytical psychology and how it has been revisited and renamed…
Analytic validity of genetic tests to identify factor V Leiden and prothrombin G20210A.
Emadi, Ashkan; Crim, Matthew T; Brotman, Daniel J; Necochea, Alejandro J; Samal, Lipika; Wilson, Lisa M; Bass, Eric B; Segal, Jodi B
2010-04-01
The objective of this study is to systematically review methods for detecting Factor V Leiden or prothrombin G20210A. English-language literature from MEDLINE, EMBASE, The Cochrane Library, the Cumulative Index to Nursing and Allied Health Literature, PsycInfo(c), 2000-December 2008. Studies assessed methods for detection of these mutations in at least 10 human blood samples and reported concordance, discordance, or reproducibility. Two investigators abstracted data on the sample selection criteria, test operators, DNA extraction, experimental test, reference standard, commercial instruments, concordance rates, explanation of any discordance, and whether discordance resolved after repetition. We assessed strength of the evidence using the GRADE criteria. We reviewed 7,777 titles and included 66 articles. The majority of the reviewed studies used PCR-RFLP or AS-PCR as the reference standard. The studies demonstrated that commercially available and precommercial tests have high analytic validity with all having greater than 99% concordance with the reference standard. With a few exceptions, discordance resolved with repetition of the test, suggesting operator or administrative errors were responsible for the discordant results. In the quality assurance studies, greater than 98% of laboratories demonstrated high, even perfect, accuracy when asked to diagnose a sample with a known mutation. The majority of errors came from a limited number of laboratories. Although not all methods may be accurate, there is high-grade evidence that genetic tests for the detection of FVL and prothrombin G20210A have excellent analytic validity. There is high-grade evidence that most, but not all, clinical laboratories test for FVL and prothrombin G20210A accurately.
Super stellar clusters with a bimodal hydrodynamic solution: an Approximate Analytic Approach
Wünsch, R; Palous, J; Tenorio-Tagle, G
2007-01-01
We look for a simple analytic model to distinguish between stellar clusters undergoing a bimodal hydrodynamic solution from those able to drive only a stationary wind. Clusters in the bimodal regime undergo strong radiative cooling within their densest inner regions, which results in the accumulation of the matter injected by supernovae and stellar winds and eventually in the formation of further stellar generations, while their outer regions sustain a stationary wind. The analytic formulae are derived from the basic hydrodynamic equations. Our main assumption, that the density at the star cluster surface scales almost linearly with that at the stagnation radius, is based on results from semi-analytic and full numerical calculations. The analytic formulation allows for the determination of the threshold mechanical luminosity that separates clusters evolving in either of the two solutions. It is possible to fix the stagnation radius by simple analytic expressions and thus to determine the fractions of the depo...
A cross-battery, reference variable, confirmatory factor analytic investigation of the CHC taxonomy.
Reynolds, Matthew R; Keith, Timothy Z; Flanagan, Dawn P; Alfonso, Vincent C
2013-08-01
The Cattell-Horn-Carroll (CHC) taxonomy has been used to classify and describe human cognitive abilities. The ability factors derived from the CHC taxonomy are often assumed to be invariant across multiple populations and intelligence batteries, which is an important assumption for research and assessment. In this study, data from five different test batteries that were collected during separate Kaufman Assessment Battery for Children-Second Edition (KABC-II; Kaufman & Kaufman, 2004) concurrent validity studies were factor-analyzed jointly. Because the KABC-II was administered to everyone in the validity studies, it was used as a reference battery to link the separate test batteries in a "cross-battery" confirmatory factor analysis. Some findings from this analysis were that CHC-based test classifications based on theory and prior research were straightforward and accurate, a first-order Fluid/Novel Reasoning (Gf) factor was equivalent to a second-order g factor, and sample heterogeneity related to SES and sex influenced factor loadings. It was also shown that a reference variable approach, used in studies that incorporate planned missingness into data collection, may be used successfully to analyze data from several test batteries and studies. One implication from these findings is that CHC theory should continue to serve as a useful guide that can be used for intelligence research, assessment, and test development.
Fernández-Marín, Beatriz; Hernández, Antonio; Garcia-Plazaola, Jose I; Esteban, Raquel; Míguez, Fátima; Artetxe, Unai; Gómez-Sagasti, Maria T
2017-01-01
Despite being a small geographic extension, Mediterranean Basin is characterized by an exceptional plant biodiversity. Adaptive responses of this biocoenosis are delineated by an unusual temporal dissociation along the year between optimal temperature for growth and water availability. This fact generates the combination of two environmental stress factors: a period of summer drought, variable in length and intensity, and the occurrence of mild to cold winters. Both abiotic factors, trigger the generation of (photo)oxidative stress and plants orchestrate an arsenal of structural, physiological, biochemical, and molecular mechanisms to withstand such environmental injuries. In the last two decades an important effort has been made to characterize the adaptive morphological and ecophysiological traits behind plant survival strategies with an eye to predict how they will respond to future climatic changes. In the present work, we have compiled data from 89 studies following a meta-analytical approach with the aim of assessing the composition and plasticity of photosynthetic pigments and low-molecular-weight antioxidants (tocopherols, glutathione, and ascorbic acid) of wild Mediterranean plant species. The influence of internal plant and leaf factors on such composition together with the stress responsiveness, were also analyzed. This approach enabled to obtain data from 73 species of the Mediterranean flora, with the genus Quercus being the most frequently studied. Main highlights of present analysis are: (i) sort of photoprotective mechanisms do not differ between Mediterranean plants and other floras but they show higher plasticity indexes; (ii) α-tocopherol among the antioxidants and violaxanthin-cycle pigments show the highest responsiveness to environmental factors; (iii) both winter and drought stresses induce overnight retention of de-epoxidised violaxanthin-cycle pigments; (iv) this retention correlates with depressions of Fv/Fm; and (v) contrary to what
Directory of Open Access Journals (Sweden)
Beatriz Fernández-Marín
2017-06-01
Full Text Available Despite being a small geographic extension, Mediterranean Basin is characterized by an exceptional plant biodiversity. Adaptive responses of this biocoenosis are delineated by an unusual temporal dissociation along the year between optimal temperature for growth and water availability. This fact generates the combination of two environmental stress factors: a period of summer drought, variable in length and intensity, and the occurrence of mild to cold winters. Both abiotic factors, trigger the generation of (photooxidative stress and plants orchestrate an arsenal of structural, physiological, biochemical, and molecular mechanisms to withstand such environmental injuries. In the last two decades an important effort has been made to characterize the adaptive morphological and ecophysiological traits behind plant survival strategies with an eye to predict how they will respond to future climatic changes. In the present work, we have compiled data from 89 studies following a meta-analytical approach with the aim of assessing the composition and plasticity of photosynthetic pigments and low-molecular-weight antioxidants (tocopherols, glutathione, and ascorbic acid of wild Mediterranean plant species. The influence of internal plant and leaf factors on such composition together with the stress responsiveness, were also analyzed. This approach enabled to obtain data from 73 species of the Mediterranean flora, with the genus Quercus being the most frequently studied. Main highlights of present analysis are: (i sort of photoprotective mechanisms do not differ between Mediterranean plants and other floras but they show higher plasticity indexes; (ii α−tocopherol among the antioxidants and violaxanthin-cycle pigments show the highest responsiveness to environmental factors; (iii both winter and drought stresses induce overnight retention of de-epoxidised violaxanthin-cycle pigments; (iv this retention correlates with depressions of Fv/Fm; and (v
Aragonés-Beltrán, Pablo; Pastor-Ferrando, Juan Pascual; García-García, Fernando; Pascual-Agulló, Amadeo
2010-05-01
In this paper the Analytic Network Process (ANP) is applied to select the best location for the construction of a municipal solid waste (MSW) plant in the Metropolitan area of Valencia (Spain). Selection of the appropriate MSW facility location can be viewed as a complex multicriteria decision-making problem that requires an extensive evaluation process of the potential MSW plant locations and other factors as diverse as economic, technical, legal, social or environmental issues. The decision-making process includes the identification of six candidate MSW plant sites and 21 criteria grouped into clusters for the construction of a network. Two technicians of the Metropolitan Waste Disposal Agency acted as decision makers (DMs). The influences between the elements of the network were identified and analyzed using the ANP multicriteria decision method. Two different ANP models were used: one hierarchy model (that considers AHP as a particular case of ANP) and another network-based model. The results obtained in each model were compared and analyzed. The strengths and weaknesses of ANP as a multicriteria decision analysis tool are also described in the paper. The main findings of this research have proved that ANP is a useful tool to help technicians to make their decision process traceable and reliable. Moreover, this approach helps DMs undertake a sound reflection of the siting problem.
Cosgrave Elizabeth M; Cotton Sue M; Buckby Joe A; Killackey Eoin J; Yung Alison R
2008-01-01
Abstract Background The Mood and Anxiety Symptom Questionnaire (MASQ) was designed to specifically measure the Tripartite model of affect and is proposed to offer a delineation between the core components of anxiety and depression. Factor analytic data from adult clinical samples has shown mixed results; however no studies employing confirmatory factor analysis (CFA) have supported the predicted structure of distinct Depression, Anxiety and General Distress factors. The Tripartite model has n...
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Shashwat Nagar
2013-04-01
Full Text Available Introduction: Increased attention to health promotion and disease prevention are important for the appropriate care of the elderly. With the increasing life expectancy, a focus on preventive measures to decrease morbidity and improve quality of life in old age has also developed. To that end, health behavior and lifestyle have become important areas of concern over the last 20 years. Social factors lay a significant impact on the health practices. This study was therefore taken up to study the above factor and draw conclusions. Aims and objectives: 1. To study the various health practices of the elderly. 2. To find out association between the socio demographic features and the prevailing health practices. Methods: A Cross sectional analytical study was carried out. All the subjects were interviewed personally to know the details and were treated with due respect after a consent. Out of all the talukas in rural Surendranagar, Sayla was selected randomly after which Sayla village was selected in a similar manner from all the villages in the talukas. Results: The mean age of the subjects was 68±7.5. Majority of the subjects were unemployed and illiterate (58%. Social factors like Social class, staying with children and staying in joint family were significantly associated with good health practices. Conclusions: The Health practices of the elderly can be improved upon by large scale health education programmes which can be targeted on the age group. Patient compliance improvement can be achieved by explaining them about the disease and treatment protocol in detail at the time of their health visit. [Int J Res Med Sci 2013; 1(2.000: 116-122
An Algebraic Approach to Form Factors
Niedermaier, M. R.
1994-01-01
An associative $*$-algebra is introduced (containing a $TTR$-algebra as a subalgebra) that implements the form factor axioms, and hence indirectly the Wightman axioms, in the following sense: Each $T$-invariant linear functional over the algebra automatically satisfies all the form factor axioms. It is argued that this answers the question (posed in the functional Bethe ansatz) how to select the dynamically correct representations of the $TTR$-algebra. Applied to the case of integrable QFTs w...
Mishra, S.; Mishra, D. R.; Tucker, C.
2011-12-01
Cyanobacterial harmful algal blooms (CHAB) are notorious for depleting dissolved oxygen level, producing various toxins, causing threats to aquatic life, altering the food-web dynamics and the overall ecosystem functioning in inland lakes, estuaries, and coastal waters. Most of these algal blooms produce various toxins that can damage cells, tissues and even cause mortality of living organisms. Frequent monitoring of water quality in a synoptic scale has been possible by the virtue of remote sensing techniques. In this research, we present a novel technique to monitor CHAB using remote sensing reflectance products. We have modified a multi-band quasi analytical algorithm that determines phytoplankton absorption coefficients from above surface remote sensing reflectance measurements using an inversion method. In situ hyperspectral remote sensing reflectance data were collected from several highly turbid and productive aquaculture ponds. A novel technique was developed to further decompose the phytoplankton absorption coefficients at 620 nm and obtain phycocyanin absorption coefficient at the same wavelength. An empirical relationship was established between phycocyanin absorption coefficients at 620 nm and measured phycocyanin concentrations. Model calibration showed strong relationship between phycocyanin absorption coefficients and phycocyanin pigment concentration (r2=0.94). Validation of the model in a separate dataset produced a root mean squared error of 167 mg m-3 (phycocyanin range: 26-1012 mg m-3). Results demonstrate that the new approach will be suitable for quantifying phycocyanin concentration in cyanobacteria dominated turbid productive waters. Band architecture of the model matches with the band configuration of the Medium Resolution Imaging Spectrometer (MERIS) and assures that MERIS reflectance products can be used to quantify phycocyanin in cyanobacterial harmful algal blooms in optically complex waters.
Morgado, Manuel P; Rolo, Sandra A; Castelo-Branco, Miguel
2011-01-01
Background: Single-pill combinations of aliskiren/hydrochlorothiazide have recently been approved by the European Medicines Agency for the treatment of hypertension. Objective: This study aimed to assess the antihypertensive efficacy of aliskiren/hydrochlorothiazide combination in reducing systolic and diastolic blood pressure in hypertensive patients. Methods: A search in International Pharmaceutical Abstracts, MEDLINE, The Cochrane Library and ISI Web of Knowledge was performed from 2000 to November 2009, to identify randomized, double-blind, clinical trials using aliskiren/hydrochlorothiazide for the treatment of hypertension. Studies were included if they evaluated the antihypertensive efficacy of aliskiren/hydrochlorothiazide in patients with mild or moderate essential hypertension and age ≥ 18 years. The meta-analytical approach calculated the weighted average reductions of systolic and diastolic blood pressure for each daily dosage combination. Results: We included 5 clinical trials testing several combinations of aliskiren/hydrochlorothiazide and containing data on 5448 patients. In all studies blood pressure was assessed at inclusion (baseline) and after 8 weeks of therapy. Blood pressure reductions and control rates were significantly (p < 0.05) higher with the aliskiren/hydrochlorothiazide combinations than with placebo and the same doses of aliskiren or hydrochlorothiazide alone. The weighted mean reductions (mm Hg) from baseline of systolic and diastolic blood pressure for each aliskiren/hydrochlorothiazide combination were: -15.8/-10.3 (150/25 mg); -15.9/-11.8 (300/12.5 mg); -16.9/-11.6 (300/25 mg). Blood pressure control rates (%) for the above combinations were, at least, respectively: 43.8, 50.1 and 51.9. Conclusions: Aliskiren/hydrochlorothiazide provided clinically significant additional blood pressure reductions and improved blood pressure control rates over aliskiren or hydrochlorothiazide monotherapy. PMID:21660247
Kanthaswamy, S
2015-10-01
This review highlights the importance of domestic animal genetic evidence sources, genetic testing, markers and analytical approaches as well as the challenges this field is facing in view of the de facto 'gold standard' human DNA identification. Because of the genetic similarity between humans and domestic animals, genetic analysis of domestic animal hair, saliva, urine, blood and other biological material has generated vital investigative leads that have been admitted into a variety of court proceedings, including criminal and civil litigation. Information on validated short tandem repeat, single nucleotide polymorphism and mitochondrial DNA markers and public access to genetic databases for forensic DNA analysis is becoming readily available. Although the fundamental aspects of animal forensic genetic testing may be reliable and acceptable, animal forensic testing still lacks the standardized testing protocols that human genetic profiling requires, probably because of the absence of monetary support from government agencies and the difficulty in promoting cooperation among competing laboratories. Moreover, there is a lack in consensus about how to best present the results and expert opinion to comply with court standards and bear judicial scrutiny. This has been the single most persistent challenge ever since the earliest use of domestic animal forensic genetic testing in a criminal case in the mid-1990s. Crime laboratory accreditation ensures that genetic test results have the courts' confidence. Because accreditation requires significant commitments of effort, time and resources, the vast majority of animal forensic genetic laboratories are not accredited nor are their analysts certified forensic examiners. The relevance of domestic animal forensic genetics in the criminal justice system is undeniable. However, further improvements are needed in a wide range of supporting resources, including standardized quality assurance and control protocols for sample
An Analytical Approach for Analysis of Slider Bearings with Non-Newtonian Lubricants
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Li-Ming Chu
2014-01-01
Full Text Available In this study, a regular perturbation technique is utilized to derive the modified Reynolds equation which is applicable to power-law lubricant. The performance of slider bearings including pressure distributions, velocity distributions, film thickness, load capacity, flow rate, shear force, and friction coefficient is also derived analytically for various ξ, flow indices (n, and outlet film thicknesses (H0. These analytical solutions are clear to find the effects of the operation parameters rather than numerical methods. It can be simply and fast used for engineers. Subsequently, these proposed analytical solutions are used to analyze the lubrication performance of slider bearing with the power-law fluids.
Analytical approach using KS elements to near-earth orbit predictions including drag
Sharma, Ram Krishnan
1991-04-01
An analytical theory for the motion of near-earth satellite orbits with the air drag effect is evolved in terms of the KS elements, using an analytical oblate exponential atmospheric density model. Due to the symmetry of the KS element equations, only one of the eight equations is integrated analytically to acquire the state vector at the close of each revolution. In the numerical studies performed, it is shown that after 100 revolutions, with a ballistic coefficient of 50, a maximum difference of 39 meters is found in the semimajor axis comparison for a very small eccentricity (0.001) instance having an initial perigee height of 391.425 km.
Modeling of Coaxial Slot Waveguides Using Analytical and Numerical Approaches: Revisited
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Kok Yeow You
2012-01-01
Full Text Available Our reviews of analytical methods and numerical methods for coaxial slot waveguides are presented. The theories, background, and physical principles related to frequency-domain electromagnetic equations for coaxial waveguides are reassessed. Comparisons of the accuracies of various types of admittance and impedance equations and numerical simulations are made, and the fringing field at the aperture sensor, which is represented by the lumped capacitance circuit, is evaluated. The accuracy and limitations of the analytical equations are explained in detail. The reasons for the replacement of analytical methods by numerical methods are outlined.
Using Gephi to visualize online course participation: a Social Learning Analytics approach
Directory of Open Access Journals (Sweden)
Ángel Hernández-García
2014-12-01
Social learning analytics provides tools and methods for extracting information that is useful for improving the learning process. This case study shows how instructors and course coordinators can use the tool Gephi to generate relevant information that would otherwise be difficult to gain. Analysis of empirical data from a cross-curricular course with 656 students proves the usefulness of Gephi for social learning analytics studies and demonstrates how the tool can provide relevant indicators of student activity and engagement. The study also discusses the potential of social learning analytics for improving online instruction via learning data visualization.
Harne, R. L.; Zhang, Chunlin; Li, Bing; Wang, K. W.
2016-07-01
Impulsive energies are abundant throughout the natural and built environments, for instance as stimulated by wind gusts, foot-steps, or vehicle-road interactions. In the interest of maximizing the sustainability of society's technological developments, one idea is to capture these high-amplitude and abrupt energies and convert them into usable electrical power such as for sensors which otherwise rely on less sustainable power supplies. In this spirit, the considerable sensitivity to impulse-type events previously uncovered for bistable oscillators has motivated recent experimental and numerical studies on the power generation performance of bistable vibration energy harvesters. To lead to an effective and efficient predictive tool and design guide, this research develops a new analytical approach to estimate the electroelastic response and power generation of a bistable energy harvester when excited by an impulse. Comparison with values determined by direct simulation of the governing equations shows that the analytically predicted net converted energies are very accurate for a wide range of impulse strengths. Extensive experimental investigations are undertaken to validate the analytical approach and it is seen that the predicted estimates of the impulsive energy conversion are in excellent agreement with the measurements, and the detailed structural dynamics are correctly reproduced. As a result, the analytical approach represents a significant leap forward in the understanding of how to effectively leverage bistable structures as energy harvesting devices and introduces new means to elucidate the transient and far-from-equilibrium dynamics of nonlinear systems more generally.
Directory of Open Access Journals (Sweden)
Xiangyu Li
2015-01-01
Full Text Available An experimental investigation on deformation shape of a cylindrical shell with internal medium subjected to lateral contact explosion was carried out briefly. Deformation shapes at different covered width of lateral explosive were recovered experimentally. Based on the experimental results, a corresponding analytical approach has been undertaken with rigid plastic hinge theory. In the analytical model, the cylindrical shell is divided into end-to-end rigid square bars. Deformation process of the cylindrical shell is described by using the translations and rotations of all rigid square bars. Expressions of the spring force, buckling moment, and deflection angle between adjacent rigid square bars are conducted theoretically. Given the structure parameters of the cylinder and the type of the lateral explosive charge, deformation processes and shapes are reported and discussed using the analytical approach. A good agreement has been obtained between calculated and experimental results, and thus the analytical approach can be considered as a valuable tool in understanding the deformation mechanism and predicting the deformation shapes of the cylindrical shell with internal medium subjected to lateral contact explosion. Finally, parametric studies are carried out to analyze the effects of deformation shape, including the covered width of the lateral explosive, explosive charge material, and distribution of initial velocity.
Converse, Sarah J.; Shelley, Kevin J.; Morey, Steve; Chan, Jeffrey; LaTier, Andrea; Scafidi, Carolyn; Crouse, Deborah T.; Runge, Michael C.
2011-01-01
The resources available to support conservation work, whether time or money, are limited. Decision makers need methods to help them identify the optimal allocation of limited resources to meet conservation goals, and decision analysis is uniquely suited to assist with the development of such methods. In recent years, a number of case studies have been described that examine optimal conservation decisions under fiscal constraints; here we develop methods to look at other types of constraints, including limited staff and regulatory deadlines. In the US, Section Seven consultation, an important component of protection under the federal Endangered Species Act, requires that federal agencies overseeing projects consult with federal biologists to avoid jeopardizing species. A benefit of consultation is negotiation of project modifications that lessen impacts on species, so staff time allocated to consultation supports conservation. However, some offices have experienced declining staff, potentially reducing the efficacy of consultation. This is true of the US Fish and Wildlife Service's Washington Fish and Wildlife Office (WFWO) and its consultation work on federally-threatened bull trout (Salvelinus confluentus). To improve effectiveness, WFWO managers needed a tool to help allocate this work to maximize conservation benefits. We used a decision-analytic approach to score projects based on the value of staff time investment, and then identified an optimal decision rule for how scored projects would be allocated across bins, where projects in different bins received different time investments. We found that, given current staff, the optimal decision rule placed 80% of informal consultations (those where expected effects are beneficial, insignificant, or discountable) in a short bin where they would be completed without negotiating changes. The remaining 20% would be placed in a long bin, warranting an investment of seven days, including time for negotiation. For formal
Combined analytical and numerical approaches in Dynamic Stability analyses of engineering systems
Náprstek, Jiří
2015-03-01
Dynamic Stability is a widely studied area that has attracted many researchers from various disciplines. Although Dynamic Stability is usually associated with mechanics, theoretical physics or other natural and technical disciplines, it is also relevant to social, economic, and philosophical areas of our lives. Therefore, it is useful to occasionally highlight the general aspects of this amazing area, to present some relevant examples and to evaluate its position among the various branches of Rational Mechanics. From this perspective, the aim of this study is to present a brief review concerning the Dynamic Stability problem, its basic definitions and principles, important phenomena, research motivations and applications in engineering. The relationships with relevant systems that are prone to stability loss (encountered in other areas such as physics, other natural sciences and engineering) are also noted. The theoretical background, which is applicable to many disciplines, is presented. In this paper, the most frequently used Dynamic Stability analysis methods are presented in relation to individual dynamic systems that are widely discussed in various engineering branches. In particular, the Lyapunov function and exponent procedures, Routh-Hurwitz, Liénard, and other theorems are outlined together with demonstrations. The possibilities for analytical and numerical procedures are mentioned together with possible feedback from experimental research and testing. The strengths and shortcomings of these approaches are evaluated together with examples of their effective complementing of each other. The systems that are widely encountered in engineering are presented in the form of mathematical models. The analyses of their Dynamic Stability and post-critical behaviour are also presented. The stability limits, bifurcation points, quasi-periodic response processes and chaotic regimes are discussed. The limit cycle existence and stability are examined together with their
Predicting the accumulation of mercury-contaminated sediment on riverbanks—An analytical approach
Pizzuto, Jim
2012-07-01
Mercury was introduced into the South River, Virginia, as a result of industrial use from 1929 to 1950. To guide remediation, an analytical model is developed to predict the mercury inventory resulting from deposition of mercury-contaminated sediment on subhorizontal surfaces adjacent to the river channel from 1930 to 2007. Sediment cores and geomorphic data were obtained from 27 sites. Mercury inventories range from 0.00019 to 0.573 kg m-2. High mercury inventories are associated with frequent inundation by floodwaters, forested riparian vegetation, and (at only four sites) unusually high sediment accumulation. Over the 10 km study reach, mercury inventories do not vary with downstream distance. The frequency of inundation at each coring site is determined from hydrologic data and a streamtube stage-discharge model. Water levels are exponentially distributed. A simple parameterization represents the enhanced ability of forested vegetation to trap mercury-contaminated sediments compared to nonforest vegetation. The calibrated model explains 62% of the observed variation in mercury inventories; 15 of the 27 predicted values are within a factor of 1.8 of the observed values. Calibration indicates a mercury deposition rate during inundation of 0.040 kg m-2 yr-1 (95% C.I. 0.032-0.048), that forested areas accumulate mercury-contaminated sediment 3.05 (95% C.I. 2.43-3.67) times faster than nonforested areas, and that floodwaters deeper than 0.98 (95% C.I. 0.45-1.53) m do not accumulate suspended sediment or mercury. At four sites, floodplain accumulation of 0.8-1.2 m occurred over a period of 39 (95% C.I. 22-56) years, while sedimentation is negligible (mean: 0.1 m, median: 0.03 m) at other sites.
Directory of Open Access Journals (Sweden)
Rakhshan Ihsan
Full Text Available Complex disease such as cancer results from interactions of multiple genetic and environmental factors. Studying these factors singularly cannot explain the underlying pathogenetic mechanism of the disease. Multi-analytical approach, including logistic regression (LR, classification and regression tree (CART and multifactor dimensionality reduction (MDR, was applied in 188 lung cancer cases and 290 controls to explore high order interactions among xenobiotic metabolizing genes and environmental risk factors. Smoking was identified as the predominant risk factor by all three analytical approaches. Individually, CYP1A1*2A polymorphism was significantly associated with increased lung cancer risk (OR = 1.69;95%CI = 1.11-2.59,p = 0.01, whereas EPHX1 Tyr113His and SULT1A1 Arg213His conferred reduced risk (OR = 0.40;95%CI = 0.25-0.65,p<0.001 and OR = 0.51;95%CI = 0.33-0.78,p = 0.002 respectively. In smokers, EPHX1 Tyr113His and SULT1A1 Arg213His polymorphisms reduced the risk of lung cancer, whereas CYP1A1*2A, CYP1A1*2C and GSTP1 Ile105Val imparted increased risk in non-smokers only. While exploring non-linear interactions through CART analysis, smokers carrying the combination of EPHX1 113TC (Tyr/His, SULT1A1 213GG (Arg/Arg or AA (His/His and GSTM1 null genotypes showed the highest risk for lung cancer (OR = 3.73;95%CI = 1.33-10.55,p = 0.006, whereas combined effect of CYP1A1*2A 6235CC or TC, SULT1A1 213GG (Arg/Arg and betel quid chewing showed maximum risk in non-smokers (OR = 2.93;95%CI = 1.15-7.51,p = 0.01. MDR analysis identified two distinct predictor models for the risk of lung cancer in smokers (tobacco chewing, EPHX1 Tyr113His, and SULT1A1 Arg213His and non-smokers (CYP1A1*2A, GSTP1 Ile105Val and SULT1A1 Arg213His with testing balance accuracy (TBA of 0.6436 and 0.6677 respectively. Interaction entropy interpretations of MDR results showed non-additive interactions of tobacco chewing with
Band structure and Bloch states in birefringent 1D magnetophotonic crystals: An analytical approach
Lévy, M; Levy, Miguel; Jalali, Amir A
2007-01-01
An analytical formulation for the band structure and Bloch modes in elliptically birefringent magnetophotonic crystals is presented. The model incorporates both the effects of gyrotropy and linear birefringence generally present in magneto-optic thin film devices. Full analytical expressions are obtained for the dispersion relation and Bloch modes in a layered stack photonic crystal and their properties are analyzed. It is shown that other models recently discussed in the literature are contained as special limiting cases of the formulation presented herein.
An analytic approach to the design of survivable optical mesh networks
Bhardwaj, Manish
2007-12-01
One of the key components of the cost of building and operating optical mesh communication networks is the requirement of survivability and many mesh survivability schemes have been suggested and their cost and performance numerically evaluated in the literature. However, little work has been done in developing comprehensive and tractable analytic models of the requirements in terms of capacity deployment and performance of the different mesh restoration schemes. Such analytic models are all the more significant given the large computation time required to numerically evaluate every possible network scenario. The focus of this thesis is to fill this void in our understanding of the costs and performance of mesh restoration schemes. Analytic models of the capacity requirements of mesh restoration schemes are presented and the accuracy of the analytic models evaluated over a wide range of network scenarios. Analytic models of the temporal performance of mesh restoration schemes are also presented thus extending for the first time the network modeling effort into the operational expenditure domain. Consequently, the number and nature of variables incorporated into the analysis is also enhanced from just the network topology and demand profile to include the switch hardware and routing protocols. We show for the first time in a quantifiable fashion the consequences of certain technology choices on the operational expenditure of optical mesh networks. Finally, the analytic models are leveraged to design a novel mesh network restoration architecture with lower restoration capacity requirement and better temporal performance than existing architectures. Such an architecture, although relevant in its own right due to its lower cost and better performance also represents a paradigm shift in the design philosophy of mesh networks wherein the analytic model guides the design process and numerical analysis confirms improvements predicted by the model. Future applications of
Salsman, John M; Pustejovsky, James E; Jim, Heather S L; Munoz, Alexis R; Merluzzi, Thomas V; George, Login; Park, Crystal L; Danhauer, Suzanne C; Sherman, Allen C; Snyder, Mallory A; Fitchett, George
2015-11-01
Religion and spirituality (R/S) are patient-centered factors and often are resources for managing the emotional sequelae of the cancer experience. Studies investigating the correlation between R/S (eg, beliefs, experiences, coping) and mental health (eg, depression, anxiety, well being) in cancer have used very heterogeneous measures and have produced correspondingly inconsistent results. A meaningful synthesis of these findings has been lacking; thus, the objective of this review was to conduct a meta-analysis of the research on R/S and mental health. Four electronic databases were systematically reviewed, and 2073 abstracts met initial selection criteria. Reviewer pairs applied standardized coding schemes to extract indices of the correlation between R/S and mental health. In total, 617 effect sizes from 148 eligible studies were synthesized using meta-analytic generalized estimating equations, and subgroup analyses were performed to examine moderators of effects. The estimated mean correlation (Fisher z) was 0.19 (95% confidence interval [CI], 0.16-0.23), which varied as a function of R/S dimensions: affective R/S (z = 0.38; 95% CI, 0.33-0.43), behavioral R/S (z = 0.03; 95% CI, -0.02-0.08), cognitive R/S (z = 0.10; 95% CI, 0.06-0.14), and 'other' R/S (z = 0.08; 95% CI, 0.03-0.13). Aggregate, study-level demographic and clinical factors were not predictive of the relation between R/S and mental health. There was little indication of publication or reporting biases. The correlation between R/S and mental health generally was positive. The strength of that correlation was modest and varied as a function of the R/S dimensions and mental health domains assessed. The identification of optimal R/S measures and more sophisticated methodological approaches are needed to advance research.
Salsman, John M.; Pustejovsky, James E.; Jim, Heather S.L.; Munoz, Alexis R.; Merluzzi, Thomas V.; George, Login; Park, Crystal L.; Danhauer, Suzanne C.; Sherman, Allen C.; Snyder, Mallory A.; Fitchett, George
2015-01-01
Purpose Religion and spirituality (R/S) are patient-centered factors and often resources for managing the emotional sequelae of the cancer experience. Studies investigating the relationship between R/S (e.g., beliefs, experiences, coping) and mental health (e.g., depression, anxiety, well-being) in cancer have used very heterogeneous measures, with correspondingly inconsistent results. A meaningful synthesis of these findings has been lacking; thus, the purpose of this study was to conduct a meta-analysis of the research on R/S and mental health. Methods Four electronic databases were systematically reviewed and 2,073 abstracts met initial selection criteria. Reviewer pairs applied standardized coding schemes to extract correlational indices of the relationship between R/S and mental health. A total of 617 effect sizes from 148 eligible studies were synthesized using meta-analytic generalized estimating equations; subgroup analyses were performed to examine moderators of effects. Results The estimated mean correlation (Fisher z) was 0.19 (95% CI 0.16–0.23), which varied as a function of R/S dimension: affective, z=0.38 (95% CI 0.33-0.43); behavioral, z=0.03 (95% CI -0.02-0.08); cognitive, z=0.10 (95% CI 0.06-0.14); and ‘other,’ z=0.08 (95% CI 0.03-0.13). Aggregate, study-level demographic and clinical factors were not predictive of the relationship between R/S and mental health. There was little indication of publication or reporting biases. Conclusions The relationship between R/S and mental health is generally a positive one. The strength of that relationship is modest and varies as a function of R/S dimensions and mental health domains assessed. Identification of optimal R/S measures and more sophisticated methodological approaches are needed to advance research. PMID:26258536
Tang, Sanyi; Xiao, Yanni
2007-12-01
The purpose of this article is to provide the analytical solutions of one-compartment models with Michaelis-Menten elimination kinetics for three different inputs (single intravenous dose, multiple-dose bolus injection and constant). All analytical solutions obtained in present paper can be described by the well defined Lambert W function which can be easily implemented in most mathematical softwares such as Matlab and Maple. These results will play an important role in fitting the Michaelis-Menten parameters and in designing a dosing regimen to maintain steady-state plasma concentrations. In particular, the analytical periodic solution for multi-dose inputs is also given, and we note that the maximum and minimum values of the periodic solution depends on the Michaelis-Menten parameters, dose and time interval of drug administration. In practice, it is important to maintain a concentration above the minimum therapeutic level at all times without exceeding the minimum toxic concentration. Therefore, the one-compartment model with therapeutic window is proposed, and further the existence of periodic solution, analytical expression and its period are analyzed. The analytical formula of period plays a key role in designing a dose regimen to maintain the plasma concentration within a specified range over long periods of therapy. Finally, the completely analytical solution for the constant input rate is derived and discussed which depends on the relations between constant input rate and maximum rate of change of concentration.
Factors Influencing Beliefs for Adoption of a Learning Analytics Tool: An Empirical Study
Ali, Liaqat; Asadi, Mohsen; Gasevic, Dragan; Jovanovic, Jelena; Hatala, Marek
2013-01-01
Present research and development offer various learning analytics tools providing insights into different aspects of learning processes. Adoption of a specific tool for practice is based on how its learning analytics are perceived by educators to support their pedagogical and organizational goals. In this paper, we propose and empirically validate…
Learning Approaches, Demographic Factors to Predict Academic Outcomes
Nguyen, Tuan Minh
2016-01-01
Purpose: The purpose of this paper is to predict academic outcome in math and math-related subjects using learning approaches and demographic factors. Design/Methodology/Approach: ASSIST was used as the instrumentation to measure learning approaches. The study was conducted in the International University of Vietnam with 616 participants. An…
HSE management excellence: a Human Factors approach
Directory of Open Access Journals (Sweden)
Roberto Theobald
2007-04-01
Full Text Available Present work discusses the integration of Human Factors in Health, Safety and Enviroment(HSE Management System allowing it as a way of checking the progress obtained, therebyminimizing the efforts and maximizing the result. A bibliographical research was carried outon the theoretical elements of the theme. As a result of this work, a proposal “conceptualstructure” for the integration of “Humais Factors” with the HSE management system ofAssociation of Oil & Gas Produces was presented.
[Risk factors for cesarean section: epidemiologic approach].
Trujillo Hernández, B; Tene Pérez, C E; Ríos Silva, M
2000-07-01
The increase in frequency of cesareans that has been noted through 70's, not diminished--like it was expected--perinatal morbidity and mortality. The most important indications to cesarean are distocias, previous cesarean and fetal stress. In 1998 frequency of cesarean deliveries in our hospital was 35% of the pregnancy attended. The claim of this study was to determine risks factors to cesarean in our hospital. A case-control study was performed, selecting 165 cases (cesareans) and 328 controls (via vaginal). It was determined OR of the risks factors and atribuible fraction. Data were analyzed by X2. The most important indications to cesarean delivery were: distocias (39%, n = 64); previous cesarean (23%, n = 41) and fetal stress (11%, n = 21). There was not significative differences in age, height and rupture membrane time in both groups. History of cesarean delivery gave major risk to another surgical intervention (OR = 12.7, p = < 0.0001, atribuible fraction 92%). Nuliparous (OR = 6.6, p < 0.00000, atribuible fraction 85%), second gestation (OR = 1.8, p = 0.002) or history of abortion (OR = 1.8, p = 0.04) were factors mainly associated to cesarean delivery. We concluded that the precise 'medications of this surgical intervention specially in nuliparous or previous cesarean delivery cases must be replanteated to diminish its elevated frequency.
Bonaduce, Ilaria; Ribechini, Erika; Modugno, Francesca; Colombini, Maria Perla
2016-02-01
Gas chromatography/mass spectrometry (GC/MS), after appropriate wet chemical sample pre-treatments or pyrolysis, is one of the most commonly adopted analytical techniques in the study of organic materials from cultural heritage objects. Organic materials in archaeological contexts, in classical art objects, or in modern and contemporary works of art may be the same or belong to the same classes, but can also vary considerably, often presenting different ageing pathways and chemical environments. This paper provides an overview of the literature published in the last 10 years on the research based on the use of GC/MS for the analysis of organic materials in artworks and archaeological objects. The latest progresses in advancing analytical approaches, characterising materials and understanding their degradation, and developing methods for monitoring their stability are discussed. Case studies from the literature are presented to examine how the choice of the working conditions and the analytical approaches is driven by the analytical and technical question to be answered, as well as the nature of the object from which the samples are collected.
Fahad, M.; Iqbal, Y.; Riaz, M.; Ubic, R.; Redfern, S. A. T.
2015-12-01
- 628oC. The multi-analytical approach applied in the present study allows the best possible discrimination. The detailed databank relating to the quarried material, created here for the first time, provides a solid basis for possible studies on the provenance and distribution of building stones from these areas.
Vanlaar, Ward; Mayhew, Dan; Marcoux, Kyla; Wets, Geert; Brijs, Tom; Shope, Jean
2009-09-01
Most jurisdictions in North America have some version of graduated driver licensing (GDL). A sound body of evidence documenting the effectiveness of GDL programs in reducing collisions, fatalities and injuries among novice drivers is available. However, information about the relative importance of individual components of GDL is lacking. The objectives of this study are to calculate a summary statistic of GDL effectiveness and to identify the most effective components of GDL programs using a meta-analytic approach. Data from 46 American States, the District of Columbia and 11 Canadian jurisdictions are used and were obtained from the Fatality Analysis Reporting System (FARS) for the U.S. and from Transport Canada's Traffic Accident Information Database (TRAID) for Canada. The timeframe of this evaluation is 1992 through 2006, inclusive. Relative fatality risks and their 95% confidence intervals were calculated using fatality counts and population data for target and comparison groups, both in a pre-implementation and post-implementation period in each jurisdiction. The target groups were 16-, 17-, 18- and 19-year-old drivers. The comparison group was 25-54-year-old drivers. The relative fatality risks of all jurisdictions were summarized using the random effects DerSimonian and Laird model. Meta-regression using Restricted Maximum Likelihood (REML) and Markov Chain Monte Carlo (MCMC) Gibbs sampling was also conducted. Strong evidence in support of GDL was found. GDL had a positive and significant impact on the relative fatality risk of 16-year-old drivers (reduction of 19.1%). Significant effects were found for meta-regression models with 16-, 18- and 19-year-old drivers. These effects include length of night restriction in the learner stage, country, driver education in the learner stage and in the intermediate stage, whether night restrictions are lifted in the intermediate stage for work purposes, passenger restriction in the intermediate stage, whether
A Novel Approach for Estimating Truck Factors
Avelino, Guilherme; Passos, Leonardo; Hora, Andre; Valente, Marco Tulio
2016-01-01
Truck Factor (TF) is a metric proposed by the agile community as a tool to identify concentration of knowledge in software development environments. It states the minimal number of developers that have to be hit by a truck (or quit) before a project is incapacitated. In other words, TF helps to measure how prepared is a project to deal with developer turnover. Despite its clear relevance, few studies explore this metric. Altogether there is no consensus about how to calculate it, and no suppo...
Gonçalves, P A D; Bludov, Yu V; Peres, N M R
2016-01-01
We study electromagnetic scattering and subsequent plasmonic excitations in periodic grids of graphene ribbons. To address this problem, we develop an analytical method to describe the plasmon-assisted absorption of electromagnetic radiation by a periodic structure of graphene ribbons forming a diffraction grating for THz and mid-IR light. The major advantage of this method lies in its ability to accurately describe the excitation of graphene surface plasmons (GSPs) in one-dimensional (1D) graphene gratings without the use of both time-consuming, and computationally-demanding full-wave numerical simulations. We thus provide analytical expressions for the reflectance, transmittance and plasmon-enhanced absorbance spectra, which can be readily evaluated in any personal laptop with little-to-none programming. We also introduce a semi-analytical method to benchmark our previous results and further compare the theoretical data with spectra taken from experiments, to which we observe a very good agreement. These th...
Institute of Scientific and Technical Information of China (English)
LIU Hong-Zhun; PAN Zu-Liang; LI Peng
2006-01-01
In this article, we will derive an equality, where the Taylor series expansion around ε = 0for any asymptotical analytical solution of the perturbed partial differential equation (PDE) with perturbing parameter ε must be admitted.By making use of the equality, we may obtain a transformation, which directly map the analytical solutions of a given unperturbed PDE to the asymptotical analytical solutions of the corresponding perturbed one. The notion of Lie-B(a)cklund symmetries is introduced in order to obtain more transformations. Hence, we can directly create more transformations in virtue of known Lie-B(a)cklund symmetries and recursion operators of corresponding unperturbed equation. The perturbed Burgers equation and the perturbed Korteweg-de Vries (KdV) equation are used as examples.
Bozkaya, Uğur; Sherrill, C David
2014-11-28
Orbital-optimized MP2.5 [or simply "optimized MP2.5," OMP2.5, for short] and its analytic energy gradients are presented. The cost of the presented method is as much as that of coupled-cluster singles and doubles (CCSD) [O(N(6)) scaling] for energy computations. However, for analytic gradient computations the OMP2.5 method is only half as expensive as CCSD because there is no need to solve λ2-amplitude equations for OMP2.5. The performance of the OMP2.5 method is compared with that of the standard second-order Møller-Plesset perturbation theory (MP2), MP2.5, CCSD, and coupled-cluster singles and doubles with perturbative triples (CCSD(T)) methods for equilibrium geometries, hydrogen transfer reactions between radicals, and noncovalent interactions. For bond lengths of both closed and open-shell molecules, the OMP2.5 method improves upon MP2.5 and CCSD by 38%-43% and 31%-28%, respectively, with Dunning's cc-pCVQZ basis set. For complete basis set (CBS) predictions of hydrogen transfer reaction energies, the OMP2.5 method exhibits a substantially better performance than MP2.5, providing a mean absolute error of 1.1 kcal mol(-1), which is more than 10 times lower than that of MP2.5 (11.8 kcal mol(-1)), and comparing to MP2 (14.6 kcal mol(-1)) there is a more than 12-fold reduction in errors. For noncovalent interaction energies (at CBS limits), the OMP2.5 method maintains the very good performance of MP2.5 for closed-shell systems, and for open-shell systems it significantly outperforms MP2.5 and CCSD, and approaches CCSD(T) quality. The MP2.5 errors decrease by a factor of 5 when the optimized orbitals are used for open-shell noncovalent interactions, and comparing to CCSD there is a more than 3-fold reduction in errors. Overall, the present application results indicate that the OMP2.5 method is very promising for open-shell noncovalent interactions and other chemical systems with difficult electronic structures.
Fuller, Nathaniel J
2016-01-01
Obtaining a detailed understanding of the physical interactions between a cell and its environment often requires information about the flow of fluid surrounding the cell. Cells must be able to effectively absorb and discard material in order to survive. Strategies for nutrient acquisition and toxin disposal, which have been evolutionarily selected for their efficacy, should reflect knowledge of the physics underlying this mass transport problem. Motivated by these considerations, in this paper we consider a two-dimensional advection-diffusion problem at small Reynolds number and large P\\'eclet number. We discuss the problem of mass transport for a circular cell in a uniform far-field flow. We approach the problem numerically, and also analytically through a rescaling of the concentration boundary layer. A biophysically motivated first-passage problem for the absorption of material by the cell demonstrates quantitative agreement between the numerical and analytical approaches.
Carter, James L.; Resh, Vincent H.
2013-01-01
Biomonitoring programs based on benthic macroinvertebrates are well-established worldwide. Their value, however, depends on the appropriateness of the analytical techniques used. All United States State, benthic macroinvertebrate biomonitoring programs were surveyed regarding the purposes of their programs, quality-assurance and quality-control procedures used, habitat and water-chemistry data collected, treatment of macroinvertebrate data prior to analysis, statistical methods used, and data-storage considerations. State regulatory mandates (59 percent of programs), biotic index development (17 percent), and Federal requirements (15 percent) were the most frequently reported purposes of State programs, with the specific tasks of satisfying the requirements for 305b/303d reports (89 percent), establishment and monitoring of total maximum daily loads, and developing biocriteria being the purposes most often mentioned. Most states establish reference sites (81 percent), but classify them using State-specific methods. The most often used technique for determining the appropriateness of a reference site was Best Professional Judgment (86 percent of these states). Macroinvertebrate samples are almost always collected by using a D-frame net, and duplicate samples are collected from approximately 10 percent of sites for quality assurance and quality control purposes. Most programs have macroinvertebrate samples processed by contractors (53 percent) and have identifications confirmed by a second taxonomist (85 percent). All States collect habitat data, with most using the Rapid Bioassessment Protocol visual-assessment approach, which requires ~1 h/site. Dissolved oxygen, pH, and conductivity are measured in more than 90 percent of programs. Wide variation exists in which taxa are excluded from analyses and the level of taxonomic resolution used. Species traits, such as functional feeding groups, are commonly used (96 percent), as are tolerance values for organic pollution
Response of plasmonic resonant nanorods: an analytical approach to optical antennas.
Kalousek, Radek; Dub, Petr; Břínek, Lukáš; Šikola, Tomáš
2012-07-30
An analytical model of the response of a free-electron gas within the nanorod to the incident electromagnetic wave is developed to investigate the optical antenna problem. Examining longitudinal oscillations of the free-electron gas along the antenna nanorod a simple formula for antenna resonance wavelengths proving a linear scaling is derived. Then the nanorod polarizability and scattered fields are evaluated. Particularly, the near-field amplitudes are expressed in a closed analytical form and the shift between near-field and far-field intensity peaks is deduced.
Rainer Diaz-Bone
2006-01-01
Abstract: The German discourse researcher Siegfried JÄGER from Duisburg is the first to have published a German-language book about the methodology of discourse analysis after FOUCAULT. JÄGER integrates in his work the discourse analytic work of Jürgen LINK as well as the interdisciplinary discussion carried on in the discourse analytic journal "kultuRRevolution" (Journal for Applied Discourse Analysis). JÄGER and his co-workers were associated with the Duisburger Institute for Language Resea...
DEFF Research Database (Denmark)
Bellotti, Filipe Furlan; Salami Dehkharghani, Amin; Zinner, Nikolaj Thomas
2017-01-01
We investigate one-dimensional harmonically trapped two-component systems for repulsive interaction strengths ranging from the non-interacting to the strongly interacting regime for Fermi-Fermi mixtures. A new and powerful mapping between the interaction strength parameters from a continuous......) and exact diagonalization) and analytically. Since DMRG results do not converge as the interaction strength is increased, analytical solutions are used as a benchmark to identify the point where these calculations become unstable. We use the proposed mapping to set a quantitative limit on the interaction...
Institute of Scientific and Technical Information of China (English)
CAI Liang; ZHANG Ping; YANG Tao; PAN Xiao-Yin
2011-01-01
By using the path integral approach, we investigate the problem of Hooke's atom (two electrons interacting with Coulomb potential in an external harmonic-oscillator potential) in an arbitrary time-dependent electric field. For a certain infinite set of discrete oscillator frequencies, we obtain the analytical solutions. The ground state polarization of the atom is then calculated. The same result is also obtained through linear response theory.
Radek eTrnka; Alek eLačev; Karel eBalcar; Martin eKuška; Peter eTavel
2016-01-01
The widely accepted two-dimensional circumplex model of emotions posits that most instances of human emotional experience can be understood within the two general dimensions of valence and activation. Currently, this model is facing some criticism, because complex emotions in particular are hard to define within only these two general dimensions. The present theory-driven study introduces an innovative analytical approach working in a way other than the conventional, two-dimensional paradigm....
Hajrahimi, Nafiseh; Dehaghani, Sayed Mehdi Hejazi; Hajrahimi, Nargess; Sarmadi, Sima
2014-01-01
Implementing information technology in the best possible way can bring many advantages such as applying electronic services and facilitating tasks. Therefore, assessment of service providing systems is a way to improve the quality and elevate these systems including e-commerce, e-government, e-banking, and e-learning. This study was aimed to evaluate the electronic services in the website of Isfahan University of Medical Sciences in order to propose solutions to improve them. Furthermore, we aim to rank the solutions based on the factors that enhance the quality of electronic services by using analytic hierarchy process (AHP) method. Non-parametric test was used to assess the quality of electronic services. The assessment of propositions was based on Aqual model and they were prioritized using AHP approach. The AHP approach was used because it directly applies experts' deductions in the model, and lead to more objective results in the analysis and prioritizing the risks. After evaluating the quality of the electronic services, a multi-criteria decision making frame-work was used to prioritize the proposed solutions. Non-parametric tests and AHP approach using Expert Choice software. The results showed that students were satisfied in most of the indicators. Only a few indicators received low satisfaction from students including, design attractiveness, the amount of explanation and details of information, honesty and responsiveness of authorities, and the role of e-services in the user's relationship with university. After interviewing with Information and Communications Technology (ICT) experts at the university, measurement criteria, and solutions to improve the quality were collected. The best solutions were selected by EC software. According to the results, the solution "controlling and improving the process in handling users complaints" is of the utmost importance and authorities have to have it on the website and place great importance on updating this process
Career Decision Statuses among Portuguese Secondary School Students: A Cluster Analytical Approach
Santos, Paulo Jorge; Ferreira, Joaquim Armando
2012-01-01
Career indecision is a complex phenomenon and an increasing number of authors have proposed that undecided individuals do not form a group with homogeneous characteristics. This study examines career decision statuses among a sample of 362 12th-grade Portuguese students. A cluster-analytical procedure, based on a battery of instruments designed to…
Feynman Path Integral Approach to Electron Diffraction for One and Two Slits: Analytical Results
Beau, Mathieu
2012-01-01
In this paper we present an analytic solution of the famous problem of diffraction and interference of electrons through one and two slits (for simplicity, only the one-dimensional case is considered). In addition to exact formulae, various approximations of the electron distribution are shown which facilitate the interpretation of the results.…
A Social Media Practicum: An Action-Learning Approach to Social Media Marketing and Analytics
Atwong, Catherine T.
2015-01-01
To prepare students for the rapidly evolving field of digital marketing, which requires more and more technical skills every year, a social media practicum creates a learning environment in which students can apply marketing principles and become ready for collaborative work in social media marketing and analytics. Using student newspapers as…
Cheung, Mike W. L.; Chan, Wai
2009-01-01
Structural equation modeling (SEM) is widely used as a statistical framework to test complex models in behavioral and social sciences. When the number of publications increases, there is a need to systematically synthesize them. Methodology of synthesizing findings in the context of SEM is known as meta-analytic SEM (MASEM). Although correlation…
Empirical Evaluation of Meta-Analytic Approaches for Nutrient and Health Outcome Dose-Response Data
Yu, Winifred W.; Schmid, Christopher H.; Lichtenstein, Alice H.; Lau, Joseph; Trikalinos, Thomas A.
2013-01-01
The objective of this study is to empirically compare alternative meta-analytic methods for combining dose-response data from epidemiological studies. We identified meta-analyses of epidemiological studies that analyzed the association between a single nutrient and a dichotomous outcome. For each topic, we performed meta-analyses of odds ratios…
Mattarozzi, Monica; Suman, Michele; Cascio, Claudia; Calestani, Davide; Weigel, Stefan; Undas, Anna; Peters, Ruud
2016-01-01
Estimating consumer exposure to nanomaterials (NMs) in food products and predicting their toxicological properties are necessary steps in the assessment of the risks of this technology. To this end, analytical methods have to be available to detect, characterize and quantify NMs in food and mater
Organic geochemistry of Amynteo lignite deposit, northern Greece: a Multi-analytical approach
Iordanidis, A.; Schwarzbauer, J.; Georgakopoulos, A.; Lagen, van B.
2012-01-01
Several lignite samples were collected from boreholes of the Amynteo opencast lignite mine, northern Greece. Organic geochemical characteristics were investigated with the help of various analytical techniques, comprising Gas Chromatography (GC) and Gas-chromatography-Mass Spectrometry (GC-MS), Four
A Social Media Practicum: An Action-Learning Approach to Social Media Marketing and Analytics
Atwong, Catherine T.
2015-01-01
To prepare students for the rapidly evolving field of digital marketing, which requires more and more technical skills every year, a social media practicum creates a learning environment in which students can apply marketing principles and become ready for collaborative work in social media marketing and analytics. Using student newspapers as…
Mattarozzi, Monica; Suman, Michele; Cascio, Claudia; Calestani, Davide; Weigel, Stefan; Undas, Anna; Peters, Ruud
2017-01-01
Estimating consumer exposure to nanomaterials (NMs) in food products and predicting their toxicological properties are necessary steps in the assessment of the risks of this technology. To this end, analytical methods have to be available to detect, characterize and quantify NMs in food and mater
A Comparison of Analytic and Synthetic Approaches to the Teaching of College Writing.
Witte, Stephen P.; Faigley, Lester
This report provides information drawn from a study that compared two components of the freshman English program at the University of Texas at Austin. The first chapter of the report contains background material and describes the two course components--the analytic option, which emphasizes writing skills in the context of complete pieces of…
Boyce, Mary C.; Singh, Kuki
2008-01-01
This paper describes a student-focused activity that promotes effective learning in analytical chemistry. Providing an environment where students were responsible for their own learning allowed them to participate at all levels from designing the problem to be addressed, planning the laboratory work to support their learning, to providing evidence…
Cheung, Mike W. L.; Chan, Wai
2009-01-01
Structural equation modeling (SEM) is widely used as a statistical framework to test complex models in behavioral and social sciences. When the number of publications increases, there is a need to systematically synthesize them. Methodology of synthesizing findings in the context of SEM is known as meta-analytic SEM (MASEM). Although correlation…
Assessment of Learning in Digital Interactive Social Networks: A Learning Analytics Approach
Wilson, Mark; Gochyyev, Perman; Scalise, Kathleen
2016-01-01
This paper summarizes initial field-test results from data analytics used in the work of the Assessment and Teaching of 21st Century Skills (ATC21S) project, on the "ICT Literacy--Learning in digital networks" learning progression. This project, sponsored by Cisco, Intel and Microsoft, aims to help educators around the world enable…
Career Decision Statuses among Portuguese Secondary School Students: A Cluster Analytical Approach
Santos, Paulo Jorge; Ferreira, Joaquim Armando
2012-01-01
Career indecision is a complex phenomenon and an increasing number of authors have proposed that undecided individuals do not form a group with homogeneous characteristics. This study examines career decision statuses among a sample of 362 12th-grade Portuguese students. A cluster-analytical procedure, based on a battery of instruments designed to…
Directory of Open Access Journals (Sweden)
Sushila
2013-09-01
Full Text Available In this paper, we present an efficient analytical approach based on new homotopy perturbation sumudu transform method (HPSTM to investigate the magnetohydrodynamics (MHD viscous flow due to a stretching sheet. The viscous fluid is electrically conducting in the presence of magnetic field and the induced magnetic field is neglected for small magnetic Reynolds number. Finally, some numerical comparisons among the new HPSTM, the homotopy perturbation method and the exact solution have been made. The numerical solutions obtained by the proposed method show that the approach is easy to implement and computationally very attractive.
Li, Xing; Tao LIU; Lin, Lifeng; Song, Tie; Du, Xiaolong; Lin, Hualiang; Xiao, Jianpeng; He, Jianfeng; Liu, Liping; Zhu, Guanghu; Zeng, Weilin; Guo, Lingchuan; Cao, Zheng; Ma, Wenjun; Zhang, Yonghui
2017-01-01
Background An international spread of Zika virus (ZIKV) infection has attracted global attention in 2015. The infection also affected Guangdong province, which is located in southern China. Multiple factors, including frequent communication with South America and Southeast Asia, suitable climate (sub-tropical) for the habitat of Aedes species, may increase the risk of ZIKV disease transmission in this region. Methods An analytic hierarchy process (AHP) method was used to develop a semi-quanti...
Hanson, Jordan C.; Connolly, Amy L.
2017-05-01
The Askaryan effect describes coherent electromagnetic radiation from high-energy cascades in dense media with a collective charge. We present an analytic model of Askaryan radiation that accounts simultaneously for the three-dimensional form factor of the cascade, and quantum mechanical cascade elongation via the Landau-Pomeranchuk-Migdal effect. These calculations, and the associated open-source code, allow the user to avoid computationally intensive Monte Carlo cascade simulations. Searches for cosmogenic neutrinos in Askaryan-based detectors benefit from computational speed, because scans of Askaryan parameter-space are required to match neutrino signals. The Askaryan field is derived from cascade equations verified with Geant4 simulations, and compared with prior numerical and semi-analytic calculations. Finally, instructive cases of the model are transformed from the Fourier domain to the time-domain. Next-generation in situ detectors like ARA and ARIANNA can use analytic time-domain signal models to search for correlations with event candidates.
Institute of Scientific and Technical Information of China (English)
WANG YouYu; HUANG Tian; ZHAO XueMan; MEI JiangPing; Derek G CHETWYND
2008-01-01
Stiffness modeling is one of the most significant issues in the design of parallel kinematic machine (PKM).This paper presents a semi-analytical approach that enables the stiffness of PKM with complex machine frame geometry to be estimated effectively.This approach can be implemented by three steps:(i) decomposition of the entire system into two sub-systems associated with the parallel mechanism and the machine frame respectively;(ii) stiffness modeling of each sub-system using the analytical approach and the finite element analysis;and (iii) generation of the stiffness model of the entire system by means of linear superposition.In the modeling process of each sub-system,the virtual work princi-ple and overall deflection Jacobian are employed with special attention to the bending rigidity of the constrained passive limb and the interface stiffness of the machine frame.The stiffness distribution of a 5-DOF hybrid robot named TriVariant-B is investigated as an example to illustrate the effectivaness of this approach.The contributions of component rigidities to that of the system are evaluated using global indices.It shows that the results achieved by this approach have a good match to those obtained through finite element analysis and experiments.
Remane, Daniela; Meyer, Markus R; Wissenbach, Dirk K; Maurer, Hans H
2010-11-15
In multi-analyte procedures, sufficient separation is important to avoid interferences, particularly when using liquid chromatography/mass spectrometry (LC/MS) because of possible ion suppression or enhancement. However, even using ultra-high-performance LC, baseline separation is not always possible. For development and validation of an LC/MS/MS approach for quantification of 140 antidepressants, benzodiazepines, neuroleptics, beta-blockers, oral antidiabetics, and analytes measured in the context of brain death diagnosis in plasma, the extent of ion suppression or enhancement of co-eluting analytes within and between the drug classes was investigated using atmospheric-pressure chemical ionization (APCI) or electrospray ionization (ESI). Within the drug classes, five analytes showed ion enhancement of over 25% and six analytes ion suppression of over 25% using APCI and 16 analytes ion suppression of over 25% using ESI. Between the drug classes, two analytes showed ion suppression of over 25% using APCI. Using ESI, one analyte showed ion enhancement of over 25% and five analytes ion suppression of over 25%. These effects may influence the drug quantification using calibrators made in presence of overlapping and thus interfering analytes. Ion suppression/enhancement effects induced by co-eluting drugs of different classes present in the patient sample may also lead to false measurements using class-specific calibrators made in absence of overlapping and thus interfering analytes. In conclusion, ion suppression and enhancement tests are essential during method development and validation in LC/MS/MS multi-analyte procedures, with special regards to co-eluting analytes.
Analytical approach to cross-layer protocol optimization in wireless sensor networks
Hortos, William S.
2008-04-01
In the distributed operations of route discovery and maintenance, strong interaction occurs across mobile ad hoc network (MANET) protocol layers. Quality of service (QoS) requirements of multimedia service classes must be satisfied by the cross-layer protocol, along with minimization of the distributed power consumption at nodes and along routes to battery-limited energy constraints. In previous work by the author, cross-layer interactions in the MANET protocol are modeled in terms of a set of concatenated design parameters and associated resource levels by multivariate point processes (MVPPs). Determination of the "best" cross-layer design is carried out using the optimal control of martingale representations of the MVPPs. In contrast to the competitive interaction among nodes in a MANET for multimedia services using limited resources, the interaction among the nodes of a wireless sensor network (WSN) is distributed and collaborative, based on the processing of data from a variety of sensors at nodes to satisfy common mission objectives. Sensor data originates at the nodes at the periphery of the WSN, is successively transported to other nodes for aggregation based on information-theoretic measures of correlation and ultimately sent as information to one or more destination (decision) nodes. The "multimedia services" in the MANET model are replaced by multiple types of sensors, e.g., audio, seismic, imaging, thermal, etc., at the nodes; the QoS metrics associated with MANETs become those associated with the quality of fused information flow, i.e., throughput, delay, packet error rate, data correlation, etc. Significantly, the essential analytical approach to MANET cross-layer optimization, now based on the MVPPs for discrete random events occurring in the WSN, can be applied to develop the stochastic characteristics and optimality conditions for cross-layer designs of sensor network protocols. Functional dependencies of WSN performance metrics are described in
Kaplun, Veronika; Stepensky, David
2014-08-04
In our previous studies, we developed a nanodrug delivery system (nano-DDS) based on poly(lactic-co-glycolic acid) PLGA nanoparticles encapsulating antigenic peptide and fluorescent marker and 3-stage approach for its decoration with peptide targeting residues. The objectives of this study were (a) to develop methods for quantitative analysis of efficiency of individual conjugation steps and (b) to determine, based on these methods, the efficiency of our 3-stage approach of nano-DDS decoration. We prepared antigenic peptide-loaded PLGA-based nano-DDSs and sequentially decorated them with specific residues using carbodiimide and Click (azide-alkyne Huisgen cycloaddition using copper(I) catalysis) reactions. The extent of cargo encapsulation and release kinetics were analyzed using HPLC-based and colorimetric analytical methods. The efficiency of residue conjugation to the nano-DDSs was analyzed using FTIR spectroscopy and by quantifying the unreacted residues in the reaction mixture (i.e., by indirect analysis of reaction efficiencies). We revealed that copper, the catalyst of the Click reactions, formed complexes with unreacted targeting residues and interfered with the analysis of their conjugation efficiency. We used penicillamine (a chelator) to disrupt these complexes, and to recover the unreacted residues. Quantitative analysis revealed that 28,800-34,000 targeting residues (corresponding to 11-13 nm(2) surface area per residue) had been conjugated to a single nano-DDS using our 3-stage decoration approach, which is much higher than previously reported conjugation efficiencies. We conclude that the applied analytical tools allow quantitative analysis of nano-DDSs and the efficiency of their conjugation with targeting residues. The 3-stage decoration approach resulted in dense conjugation of nano-DDSs with targeting residues. The present decoration and analytical approaches can be effectively applied to other types of delivery systems and other targeting
Kelisani, M. Dayyani; Doebert, S.; Aslaninejad, M.
2016-08-01
The critical process of beam loading compensation in high intensity accelerators brings under control the undesired effect of the beam induced fields to the accelerating structures. A new analytical approach for optimizing standing wave accelerating structures is found which is hugely fast and agrees very well with simulations. A perturbative analysis of cavity and waveguide excitation based on the Bethe theorem and normal mode expansion is developed to compensate the beam loading effect and excite the maximum field gradient in the cavity. The method provides the optimum values for the coupling factor and the cavity detuning. While the approach is very accurate and agrees well with simulation software, it massively shortens the calculation time compared with the simulation software.
Energy Technology Data Exchange (ETDEWEB)
Kelisani, M. Dayyani, E-mail: mdayyani@cern.ch [Institute for Research in Fundamental Sciences (IPM), School of Particles and Accelerators, P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); European Organization for Nuclear Research (CERN), BE Department, CH-1211 Geneva 23 (Switzerland); Doebert, S. [European Organization for Nuclear Research (CERN), BE Department, CH-1211 Geneva 23 (Switzerland); Aslaninejad, M. [Institute for Research in Fundamental Sciences (IPM), School of Particles and Accelerators, P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)
2016-08-21
The critical process of beam loading compensation in high intensity accelerators brings under control the undesired effect of the beam induced fields to the accelerating structures. A new analytical approach for optimizing standing wave accelerating structures is found which is hugely fast and agrees very well with simulations. A perturbative analysis of cavity and waveguide excitation based on the Bethe theorem and normal mode expansion is developed to compensate the beam loading effect and excite the maximum field gradient in the cavity. The method provides the optimum values for the coupling factor and the cavity detuning. While the approach is very accurate and agrees well with simulation software, it massively shortens the calculation time compared with the simulation software.
A network analytical approach to the study of labour market mobility
DEFF Research Database (Denmark)
Toubøl, Jonas; Larsen, Anton Grau; Jensen, Carsten Strøby
The aim of this paper is to present a new network analytical method for analysis of social mobility between categories like occupations or industries. The method consists of two core components; the algorithm MONECA (Mobility Network Clustering Algorithm), and the intensity measure of Relative Ri...... of the typical theory driven definition of the labour market segments, the use of social network analysis enable a data driven definition of the segments based on the direct observation of mobility between job-positions, which reveals a number of new findings.......The aim of this paper is to present a new network analytical method for analysis of social mobility between categories like occupations or industries. The method consists of two core components; the algorithm MONECA (Mobility Network Clustering Algorithm), and the intensity measure of Relative Risk...
An Analytical Approach to Thermal and Electrical Transport in a Mesoscopic Conductor
Institute of Scientific and Technical Information of China (English)
WANG Zheng-Chuan; SU Gang; LI Ling; GAO Jie
2005-01-01
In order to consider the thermal and electrical coherent transport in a mesoscopic conductor under the influence of electron-electron interaction, in this paper, we establish a method in terms of which one can analytically obtain the Hartree self-consistent potential instead of computing it by the numerical iterative procedure as usual, which is convenient for us to describe the thermal and electric current flow through a mesoscopic conductor. If we study the electron-electron interaction at the Hartree approximation level, the Hartree potential satisfies the Poisson equation and Schrodinger equation, so when we expand the action function S(x) by Planck constant h, the self-consistent potential and the wavefunction can be solved analytically order by order, and the thermal and electrical conductance can thus be obtained readily. However, we just show the quantum corrections up to the second order.
Annual banned-substance review: analytical approaches in human sports drug testing.
Thevis, Mario; Kuuranne, Tiia; Geyer, Hans; Schänzer, Wilhelm
2017-01-01
There has been an immense amount of visibility of doping issues on the international stage over the past 12 months with the complexity of doping controls reiterated on various occasions. Hence, analytical test methods continuously being updated, expanded, and improved to provide specific, sensitive, and comprehensive test results in line with the World Anti-Doping Agency's (WADA) 2016 Prohibited List represent one of several critical cornerstones of doping controls. This enterprise necessitates expediting the (combined) exploitation of newly generated information on novel and/or superior target analytes for sports drug testing assays, drug elimination profiles, alternative test matrices, and recent advances in instrumental developments. This paper is a continuation of the series of annual banned-substance reviews appraising the literature published between October 2015 and September 2016 concerning human sports drug testing in the context of WADA's 2016 Prohibited List. Copyright © 2016 John Wiley & Sons, Ltd.
A new analytical approach to solve some of the fractional-order partial differential equations
Manafian, Jalil; Lakestani, Mehrdad
2017-03-01
The aim of the present paper is to present an analytical method for the time fractional biological population model, time fractional Burgers, time fractional Cahn-Hilliard, space-time fractional Whitham-Broer-Kaup, space-time fractional Fokas equations by using the generalized tanh-coth method. The fractional derivative is described in the sense of the modified Riemann-Liouville derivatives. The method gives an analytic solution in the form of a convergent series with easily computable components, requiring no linearization or small perturbation. We have obtained the exact solutions for the aforementioned nonlinear fractional equations. A generalized fractional complex transform is appropriately used to convert these fractional equations to ordinary differential equations which subsequently resulted into number of exact solutions.
A new analytical approach to solve some of the fractional-order partial differential equations
Manafian, Jalil; Lakestani, Mehrdad
2016-09-01
The aim of the present paper is to present an analytical method for the time fractional biological population model, time fractional Burgers, time fractional Cahn-Hilliard, space-time fractional Whitham-Broer-Kaup, space-time fractional Fokas equations by using the generalized tanh-coth method. The fractional derivative is described in the sense of the modified Riemann-Liouville derivatives. The method gives an analytic solution in the form of a convergent series with easily computable components, requiring no linearization or small perturbation. We have obtained the exact solutions for the aforementioned nonlinear fractional equations. A generalized fractional complex transform is appropriately used to convert these fractional equations to ordinary differential equations which subsequently resulted into number of exact solutions.
Analytical approach to linear fractional partial differential equations arising in fluid mechanics
Energy Technology Data Exchange (ETDEWEB)
Momani, Shaher [Department of Mathematics, Mutah University, P.O. Box 7, Al-Karak (Jordan)]. E-mail: shahermm@yahoo.com; Odibat, Zaid [Prince Abdullah Bin Ghazi Faculty of Science and IT, Al-Balqa' Applied University, Salt (Jordan)]. E-mail: odibat@bau.edu.jo
2006-07-10
In this Letter, we implement relatively new analytical techniques, the variational iteration method and the Adomian decomposition method, for solving linear fractional partial differential equations arising in fluid mechanics. The fractional derivatives are described in the Caputo sense. The two methods in applied mathematics can be used as alternative methods for obtaining analytic and approximate solutions for different types of fractional differential equations. In these methods, the solution takes the form of a convergent series with easily computable components. The corresponding solutions of the integer order equations are found to follow as special cases of those of fractional order equations. Some numerical examples are presented to illustrate the efficiency and reliability of the two methods.
Bellotti, Filipe F.; Dehkharghani, Amin S.; Zinner, Nikolaj T.
2017-02-01
We investigate one-dimensional harmonically trapped two-component systems for repulsive interaction strengths ranging from the non-interacting to the strongly interacting regime for Fermi-Fermi mixtures. A new and powerful mapping between the interaction strength parameters from a continuous Hamiltonian and a discrete lattice Hamiltonian is derived. As an example, we show that this mapping does not depend neither on the state of the system nor on the number of particles. Energies, density profiles and correlation functions are obtained both numerically (density matrix renormalization group (DMRG) and exact diagonalization) and analytically. Since DMRG results do not converge as the interaction strength is increased, analytical solutions are used as a benchmark to identify the point where these calculations become unstable. We use the proposed mapping to set a quantitative limit on the interaction parameter of a discrete lattice Hamiltonian above which DMRG gives unrealistic results.
An Analytical Approach to Scattering Between Two Thin Magnetic Flux Tubes in a Stratified Atmosphere
Hanson, Chris S
2014-01-01
We expand on recent studies to analytically model the behavior of two thin flux tubes interacting through the near- and acoustic far-field. The multiple scattering that occurs between the pair alters the absorption and phase of the outgoing wave, when compared to non-interacting tubes. We have included both the sausage and kink scatter produced by the pair. It is shown that the sausage mode's contribution to the scattered wave field is significant, and plays an equally important role in the multiple scattering regime. A disparity between recent numerical results and analytical studies, in particular the lack of symmetry between the two kink modes, is addressed. This symmetry break is found to be caused by an incorrect solution for the near-field modes.
An analytical and hypothesis-driven approach to elasmobranch movement studies.
Papastamatiou, Y P; Lowe, C G
2012-04-01
The study of elasmobranch movements has increased steadily since the early 1970s. A great deal is now known about the horizontal and vertical movements of many elasmobranch species over multiple spatial and temporal scales. These studies illustrate that many species share certain behaviours such as diel shifts in habitat (both horizontal and vertical), continuous yo-yo bounce diving and in many cases, seasonal migrations. Hypothesis-driven studies explaining these behaviours or utilizing an eco-physiological predictive framework are, however, relatively rare. In this review, the descriptive and hypothesis-driven studies of elasmobranch movements are discussed, in addition to some of the analytical tools that can be used to generate or test predictions. There are many tools and analytical techniques available which are not currently being utilized for most studies of elasmobranch movements. With the constant improvement in technology and statistical techniques, the development of hypothesis-driven studies of elasmobranch movements should continue to increase.
An analytical approach to scattering between two thin magnetic flux tubes in a stratified atmosphere
Energy Technology Data Exchange (ETDEWEB)
Hanson, Chris S.; Cally, Paul S., E-mail: christopher.hanson@monash.edu [Monash Centre for Astrophysics and School of Mathematical Sciences, Monash University, Clayton, Victoria 3800 (Australia)
2014-02-01
We expand on recent studies to analytically model the behavior of two thin flux tubes interacting through the near- and acoustic far-field. The multiple scattering that occurs between the pair alters the absorption and phase of the outgoing wave when compared to non-interacting tubes. We have included both the sausage and kink scatter produced by the pair. It is shown that the sausage mode's contribution to the scattered wave field is significant, and plays an equally important role in the multiple scattering regime. A disparity between recent numerical results and analytical studies, in particular the lack of symmetry between the two kink modes, is addressed. This symmetry break is found to be caused by an incorrect solution for the near-field modes.
Chinonye Ugboma; Ogochukwu Ugboma; Innocent C Ogwude
2006-01-01
This study presents the findings of a survey to determine the service characteristics that shippers consider important when selecting a port and the way these characteristics are prioritised according to their importance. Seven criteria for the port selection decision and four ports were identified, and the decision problem was structured into a three-level hierarchy using the Analytic Hierarchy Process. The findings suggest that shippers place high emphasis on efficiency, frequency of ship v...
MULTI-ANALYTICAL APPROACH FOR THE STUDY OF GLAZED POTTERY FROM AL-FUSTAT, EGYPT
Sadek, H
2016-01-01
This work presents the archaeometric characterizations of glazed pottery from Al-Fustat by using multi- analytical techniques. Pot sherds investigated by colorimetry, Polarized Light Microscope OLM, XRD and SEM. In the studied samples, quartz added to the pottery body paste. In addition, additive materials commonly added to the raw materials such feldspars, mica, amphibole, pyroxene and calcite. Mineralogical and morphological analysis of the matrix indicate that the firing temperature carrie...
Analytical Approach to the Beam-Beam Interaction with the Hourglass Effect
AUTHOR|(CDS)2090622; Appleby, Robert Barrie
2015-01-01
The hourglass effect arises due to a coupling between the longitudinal and transverse bunch planes. This coupling will result in a charge density distribution that will vary parabolically through the Interaction Point (IP). Here a method of analytically determining the electric field a particle receives from a charge density distribution which varies parabolically when centred at the IP, is derived for a 2D transverse model of a Gaussian bunch.
CDT coupled to dimer matter: An analytical approach via tree bijections
Atkin, Max R
2012-01-01
We review a recently obtained analytical solution of a restricted so-called hard dimers model coupled to two-dimensional CDT. The combinatorial solution is obtained via bijections of causal triangulations with dimers and decorated trees. We show that the scaling limit of this model can also be obtained from a multi-critical point of the transfer matrix for dynamical triangulations of triangles and squares when one disallows for spatial topology changes to occur.
An Analytic Approach for Calculating Frame Erasue Rate in Cellular GSM Networks
Directory of Open Access Journals (Sweden)
Ahmed M. Alaa
2013-11-01
Full Text Available The Quality of Service (QoS of a GSM system is quantified in terms of Bit Error Rate (BER and Frame Erasure Rate (FER observed by the user. The problem of obtaining analytical expressions for BER and FER in a fading channel with multiple cochannel interferers (CCI is an extremely complex mathematical problem. The reason for this complexity is that the involvement of several GSM physical layer modules is required to obtain an expression for the probability of bit error. Besides, one needs to obtain the statistical properties of faded cochannel interferers in order to obtain the raw BER of GMSK modulation. Thus, error rate metrics are usually obtained by simulating the GSM physical layer rather than treating the problem analytically. A reliable interface between system and link level models can be obtained by evaluating the BER and FER in terms of the Signal-to-Interference Ratio (SIR analytically, instead of the pre-defined statistical mapping data usually used in literature. In this work, bounds on the uplink BER and FER are obtained for the GSM physical layer assuming a CCI limited system where both the desired and interference signals are subjected to Rayleigh fading. The analysis considers GMSK modulation, convolutional coding and Frequency Hopping.
Analytical Modeling of Wind Farms: A New Approach for Power Prediction
Directory of Open Access Journals (Sweden)
Amin Niayifar
2016-09-01
Full Text Available Wind farm power production is known to be strongly affected by turbine wake effects. The purpose of this study is to develop and test a new analytical model for the prediction of wind turbine wakes and the associated power losses in wind farms. The new model is an extension of the one recently proposed by Bastankhah and Porté-Agel for the wake of stand-alone wind turbines. It satisfies the conservation of mass and momentum and assumes a self-similar Gaussian shape of the velocity deficit. The local wake growth rate is estimated based on the local streamwise turbulence intensity. Superposition of velocity deficits is used to model the interaction of the multiple wakes. Furthermore, the power production from the wind turbines is calculated using the power curve. The performance of the new analytical wind farm model is validated against power measurements and large-eddy simulation (LES data from the Horns Rev wind farm for a wide range of wind directions, corresponding to a variety of full-wake and partial-wake conditions. A reasonable agreement is found between the proposed analytical model, LES data, and power measurements. Compared with a commonly used wind farm wake model, the new model shows a significant improvement in the prediction of wind farm power.
Dynamic response of cylindrical cavity to anti-plane impact load by using analytical approach
Institute of Scientific and Technical Information of China (English)
翟朝娇; 夏唐代; 杜国庆; 丁智
2014-01-01
The transient response of an unlimited cylindrical cavity buried in the infinite elastic soil subjected to an anti-plane impact load along the cavern axis direction was studied. Using Laplace transform combining with contour integral of the Laplace inverse transform specifically, the general analytical expressions of the soil displacement and stress are obtained in the time domain, respectively. And the numerical solutions of the problem computed by analytical expressions are presented. In the time domain, the dynamic responses of the infinite elastic soil are analyzed, and the calculation results are compared with those from numerical inversion proposed by Durbin and the static results. One observes good agreement between analytical and numerical inversion results, lending the further support to the method presented. Finally, some valuable shear wave propagation laws are gained:the displacement of the soil remains zero before the wave arrival, and after the shear wave arrival, the stress and the displacement at this point increase abruptly, then reduce and tend to the static value gradually at last. The wave attenuates along the radial, therefore the farther the wave is from the source, the smaller the stress and the displacement are, and the stress and the displacement are just functions of the radial distance from the axis.
Study on the behaviour of rubber aggregates concrete beams using analytical approach
Directory of Open Access Journals (Sweden)
Priyanka Asutkar
2017-02-01
Full Text Available Concrete is one the most extensively used construction material all over the world. Many scientists and researchers are in quest for developing alternate construction material that are environment friendly and contribute towards sustainable development. Huge amount of rubber tyres waste is being generated day by day which creates the disposal problem and has many environmental issues. As this scrap rubber waste is an elastic material having less specific gravity, energy absorbent material can be used as a replacement material for obtaining lightweight concrete. In present study an attempt is made to partially replace the rubber aggregates by coarse aggregates in concrete and to study its impact on properties of concrete. A modified concrete is prepared by replacing coarse aggregates in concrete with rubber aggregates by varying the replacement proportion from 0% to 20% with increment of 5%. 3 cubes for each percentage of replacement are casted and tested after 28th days of curing. The physiomechanical properties like density, compressive strength and elastic properties of modified concrete are determined from concrete cubes experimentally and further stresses and displacement at every 50 mm depth of beams are determined analytically by method of initial functions (MIF. MIF is an analytical method in which elastic properties and theoretical loads are used to analyse the beams without conducting any experimental programme. The analytical results by MIF are compared with bending theory.
Profiling Approaches to Teaching in Higher Education: A Cluster-Analytic Study
Stes, Ann; Van Petegem, Peter
2014-01-01
Teaching approaches in higher education have already been the subject of a considerable body of research. An important contribution was Prosser and Trigwell's development of the Approaches to Teaching Inventory (ATI). The present study aims to map out the approaches to teaching profiles of teachers in higher education on the basis of their scores…
Directory of Open Access Journals (Sweden)
Luisa Pellegrino
2013-05-01
Full Text Available Hen egg-white lysozyme (LSZ is currently used in the food industry to limit the proliferation of lactic acid bacteria spoilage in the production of wine and beer, and to inhibit butyric acid fermentation in hard and extra hard cheeses (late blowing caused by the outgrowth of clostridial spores. The aim of this work was to evaluate how the enzyme activity in commercial preparations correlates to the enzyme concentration and can be affected by the presence of process-related impurities. Different analytical approaches, including turbidimetric assay, SDS-PAGE and HPLC were used to analyse 17 commercial preparations of LSZ marketed in different countries. The HPLC method adopted by ISO allowed the true LSZ concentration to be determined with accuracy. The turbidimetric assay was the most suitable method to evaluate LSZ activity, whereas SDS-PAGE allowed the presence of other egg proteins, which are potential allergens, to be detected. The analytical results showed that the purity of commercially available enzyme preparations can vary significantly, and evidenced the effectiveness of combining different analytical approaches in this type of control.
Peraman, R; Bhadraya, K; Reddy, Y Padmanabha; Reddy, C Surayaprakash; Lokesh, T
2015-01-01
By considering the current regulatory requirement for an analytical method development, a reversed phase high performance liquid chromatographic method for routine analysis of etofenamate in dosage form has been optimized using analytical quality by design approach. Unlike routine approach, the present study was initiated with understanding of quality target product profile, analytical target profile and risk assessment for method variables that affect the method response. A liquid chromatography system equipped with a C18 column (250×4.6 mm, 5 μ), a binary pump and photodiode array detector were used in this work. The experiments were conducted based on plan by central composite design, which could save time, reagents and other resources. Sigma Tech software was used to plan and analyses the experimental observations and obtain quadratic process model. The process model was used for predictive solution for retention time. The predicted data from contour diagram for retention time were verified actually and it satisfied with actual experimental data. The optimized method was achieved at 1.2 ml/min flow rate of using mobile phase composition of methanol and 0.2% triethylamine in water at 85:15, % v/v, pH adjusted to 6.5. The method was validated and verified for targeted method performances, robustness and system suitability during method transfer.
Subtypes of borderline personality disorder patients: a cluster-analytic approach.
Smits, Maaike L; Feenstra, Dine J; Bales, Dawn L; de Vos, Jasmijn; Lucas, Zwaan; Verheul, Roel; Luyten, Patrick
2017-01-01
The borderline personality disorder (BPD) population is notably heterogeneous, and this has potentially important implications for intervention. Identifying distinct subtypes of patients may represent a first step in identifying which treatments work best for which individuals. A cluster-analysis on dimensional personality disorder (PD) features, as assessed with the SCID-II, was performed on a sample of carefully screened BPD patients (N = 187) referred for mentalization-based treatment. The optimal cluster solution was determined using multiple indices of fit. The validity of the clusters was explored by investigating their relationship with borderline pathology, symptom severity, interpersonal problems, quality of life, personality functioning, attachment, and trauma history, in addition to demographic and clinical features. A three-cluster solution was retained, which identified three clusters of BPD patients with distinct profiles. The largest cluster (n = 145) consisted of patients characterized by "core BPD" features, without marked elevations on other PD dimensions. A second "Extravert/externalizing" cluster of patients (n = 27) was characterized by high levels of histrionic, narcissistic, and antisocial features. A third, smaller "Schizotypal/paranoid" cluster (n = 15) consisted of patients with marked schizotypal and paranoid features. Patients in these clusters showed theoretically meaningful differences in terms of demographic and clinical features. Three meaningful subtypes of BPD patients were identified with distinct profiles. Differences were small, even when controlling for severity of PD pathology, suggesting a strong common factor underlying BPD. These results may represent a stepping stone toward research with larger samples aimed at replicating the findings and investigating differential trajectories of change, treatment outcomes, and treatment approaches for these subtypes. The study was retrospectively registered 16 April 2010 in the
Do the Critical Success Factors from Learning Analytics Predict Student Outcomes?
Strang, Kenneth David
2016-01-01
This article starts with a detailed literature review of recent studies that focused on using learning analytics software or learning management system data to determine the nature of any relationships between online student activity and their academic outcomes within university-level business courses. The article then describes how data was…
Jurjiu, Aurel; Galiceanu, Mircea; Farcasanu, Alexandru; Chiriac, Liviu; Turcu, Flaviu
2016-12-01
In this paper, we focus on the relaxation dynamics of Sierpinski hexagon fractal polymer. The relaxation dynamics of this fractal polymer is investigated in the framework of the generalized Gaussian structure model using both Rouse and Zimm approaches. In the Rouse-type approach, by performing real-space renormalization transformations, we determine analytically the complete eigenvalue spectrum of the connectivity matrix. Based on the eigenvalues obtained through iterative algebraic relations we calculate the averaged monomer displacement and the mechanical relaxation moduli (storage modulus and loss modulus). The evaluation of the dynamical properties in the Rouse-type approach reveals that they obey scaling in the intermediate time/frequency domain. In the Zimm-type approach, which includes the hydrodynamic interactions, the relaxation quantities do not show scaling. The theoretical findings with respect to scaling in the intermediate domain of the relaxation quantities are well supported by experimental results.
Light-cone sum rule approach for Baryon form factors
Offen, Nils
2016-01-01
We present the state-of-the-art of the light-cone sum rule approach to Baryon form factors. The essence of this approach is that soft Feynman contributions are calculated in terms of small transverse distance quantities using dispersion relations and duality. The form factors are thus expressed in terms of nucleon wave functions at small transverse separations, called distribution amplitudes, without any additional parameters. The distribution amplitudes, therefore, can be extracted from the comparison with the experimental data on form factors and compared to the results of lattice QCD simulations.
Light-Cone Sum Rule Approach for Baryon Form Factors
Offen, Nils
2016-10-01
We present the state-of-the-art of the light-cone sum rule approach to Baryon form factors. The essence of this approach is that soft Feynman contributions are calculated in terms of small transverse distance quantities using dispersion relations and duality. The form factors are thus expressed in terms of nucleon wave functions at small transverse separations, called distribution amplitudes, without any additional parameters. The distribution amplitudes, therefore, can be extracted from the comparison with the experimental data on form factors and compared to the results of lattice QCD simulations.
Directory of Open Access Journals (Sweden)
Natalia V. Mamaeva
2014-01-01
Full Text Available The article presents the results of analysis of functioning at university and federal levels information-analytical systems describing the scientifi c sphere. It is concluded that there is no automatic link between the information analytical systems of given levels, so an approach is suggested to architecting a single information-analytical system of state and development of scientifi c sphere in institutions of higher education.
An analytic approach to sunset diagrams in chiral perturbation theory: Theory and practice
Energy Technology Data Exchange (ETDEWEB)
Ananthanarayan, B.; Ghosh, Shayan [Indian Institute of Science, Centre for High Energy Physics, Karnataka (India); Bijnens, Johan [Lund University, Department of Astronomy and Theoretical Physics, Lund (Sweden); Hebbar, Aditya [Indian Institute of Science, Centre for High Energy Physics, Karnataka (India); University of Delaware, Department of Physics and Astronomy, Newark, DE (United States)
2016-12-15
We demonstrate the use of several code implementations of the Mellin-Barnes method available in the public domain to derive analytic expressions for the sunset diagrams that arise in the two-loop contribution to the pion mass and decay constant in three-flavoured chiral perturbation theory. We also provide results for all possible two mass configurations of the sunset integral, and derive a new one-dimensional integral representation for the one mass sunset integral with arbitrary external momentum. Thoroughly annotated Mathematica notebooks are provided as ancillary files in the Electronic Supplementary Material to this paper, which may serve as pedagogical supplements to the methods described in this paper. (orig.)
Analytical approach for temperature of the evaporating droplets on solid substrates
Dunin, Stanislav Z.; Nagornov, Oleg V.; Starostin, Nikolay V.; Trifonenkov, Vladimir P.
2016-06-01
Non-isothermal evaporation of sessile liquid drops is analyzed. For temperature and concentration distributions the analytical formulae are derived as functions of the system and ambient parameters. Non-uniform temperature distribution on drop surface results in Marangonni force. Extremes of surface temperature cause Marangonni force to change its direction in stagnation points. Critical values of system parameters, at which stagnation points take place, are found. Position of these points is derived as function of thermal properties of substrate, liquid and gas and contact angle.
A network analytical approach to the study of labour market mobility
DEFF Research Database (Denmark)
Toubøl, Jonas; Larsen, Anton Grau; Jensen, Carsten Strøby
The aim of this paper is to present a new network analytical method for analysis of social mobility between categories like occupations or industries. The method consists of two core components; the algorithm MONECA (Mobility Network Clustering Algorithm), and the intensity measure of Relative Risk...... of the typical theory driven definition of the labour market segments, the use of social network analysis enable a data driven definition of the segments based on the direct observation of mobility between job-positions, which reveals a number of new findings....
An analytical approach of thermodynamic behavior in a gas target system on a medical cyclotron.
Jahangiri, Pouyan; Zacchia, Nicholas A; Buckley, Ken; Bénard, François; Schaffer, Paul; Martinez, D Mark; Hoehr, Cornelia
2016-01-01
An analytical model has been developed to study the thermo-mechanical behavior of gas targets used to produce medical isotopes, assuming that the system reaches steady-state. It is based on an integral analysis of the mass and energy balance of the gas-target system, the ideal gas law, and the deformation of the foil. The heat transfer coefficients for different target bodies and gases have been calculated. Excellent agreement is observed between experiments performed at TRIUMF's 13 MeV cyclotron and the model. Copyright © 2015 Elsevier Ltd. All rights reserved.
Trombe walls and green-houses: an analytical approach to long-term performances analysis
Energy Technology Data Exchange (ETDEWEB)
Cuomo, V.; Fontana, F.; Serio, C.
1985-08-01
Statistical properties of sequences of solar radiation data, and RC properties of buildings suggest that, the fraction of the thermal load covered by solar passive elements can be expressed by simple analytical functions, which asymptotic behaviour is determined by the physical properties of the system. We analyse the asymptotic properties of these functions. We, then, determine their explicit expression for two cases of passive systems: Trombe walls and green-houses. Using the meteorological data of some Italian stations, we calculate also the numerical values of the parameters.
Delayed feedback control of time-delayed chaotic systems: Analytical approach at Hopf bifurcation
Energy Technology Data Exchange (ETDEWEB)
Vasegh, Nastaran [Faculty of Electrical Engineering, K.N. Toosi University of Technology, PO Box 16315-1355, Tehran (Iran, Islamic Republic of)], E-mail: vasegh@eetd.kntu.ac.ir; Sedigh, Ali Khaki [Faculty of Electrical Engineering, K.N. Toosi University of Technology, PO Box 16315-1355, Tehran (Iran, Islamic Republic of)
2008-07-28
This Letter is concerned with bifurcation and chaos control in scalar delayed differential equations with delay parameter {tau}. By linear stability analysis, the conditions under which a sequence of Hopf bifurcation occurs at the equilibrium points are obtained. The delayed feedback controller is used to stabilize unstable periodic orbits. To find the controller delay, it is chosen such that the Hopf bifurcation remains unchanged. Also, the controller feedback gain is determined such that the corresponding unstable periodic orbit becomes stable. Numerical simulations are used to verify the analytical results.
Rosen, Jacob; Lum, Mitch; Trimble, Denny; Hannaford, Blake; Sinanan, Mika
2005-01-01
Recent advances in technology have led to the fusion of MIS techniques and robot devices. However, current systems are large and cumbersome. Optimizing the surgical robot mechanism will eventually lead to its integration into the operating room (OR) of the future becoming the extended presence of the surgeon and nurses in a room occupied by the patient alone. By optimizing a spherical mechanism using data collected in-vivo during MIS procedures, this study is focused on a bottom-up approach to developing a new class of surgical robotic arms while maximizing their performance and minimizing their size. The spherical mechanism is a rotational manipulator with all axes intersecting at the center of the sphere. Locating the rotation center of the mechanism at the MIS port makes this class of mechanism a suitable candidate for the first two links of a surgical robot for MIS. The required dexterous workspace (DWS) is defined as the region in which 95% of the tool motions are contained based on in-vivo measurements. The extended dexterous workspace (EDWS) is defined as the entire abdominal cavity reachable by a MIS instruments. The DWS is defined by a right circular cone with a vertex angle of 60 degrees and the EDWS is defined by a cone with an elliptical cross section created by two orthogonal vertex angles of 60 degrees and 90 degrees. A compound function based on the mechanism's isotropy and the mechanism stiffness was considered as the performance metric cost function. Optimization across both the DWS and the EDWS lead to a serial mechanism configuration with link length angles of 74 degrees and 60 degrees for a serial configuration. This mechanism configuration maximized the kinematic performance in the DWS while keeping the EDWS as its reachable workspace. Surgeons, using a mockup of two mechanisms in a MIS setup, validated these results experimentally. From these experiments the serial configuration was deemed most applicable for MIS robotic applications compared
Brouwers, H J H
2007-10-01
The geometrical stability of the three lattices of the cubic crystal system, viz. face-centered cubic (fcc), body-centered cubic (bcc), and simple cubic (sc), consisting of bimodal discrete hard spheres, and the transition to amorphous packing is studied. First, the random close packing (rcp) fraction of binary mixtures of amorphously packed spheres is recapitulated. Next, the packing of a binary mixture of hard spheres in randomly disordered cubic structures is analyzed, resulting in original analytical expressions for the unit cell volume and the packing fraction, and which are also valid for the other five crystal systems. The bimodal fcc lattice parameter appears to be in close agreement with empirical hard sphere data from literature, and this parameter could be used to distinguish the size mismatch effect from all other effects in distorted binary lattices of materials. Here, as a first model application, bimodal amorphous and crystalline fcc/bcc packing fractions are combined, yielding the optimum packing configuration, which depends on mixture composition and diameter ratio only. Maps of the closest packing mode are established and applied to colloidal mixtures of polydisperse spheres and to binary alloys of bcc, fcc, and hcp metals. The extensive comparison between the analytical expressions derived here and the published numerical and empirical data yields good agreement. Hence, it is seen that basic space-filling theories on "simple" noninteracting hard spheres are a valuable tool for the study of crystalline materials.
Brouwers, H. J. H.
2007-10-01
The geometrical stability of the three lattices of the cubic crystal system, viz. face-centered cubic (fcc), body-centered cubic (bcc), and simple cubic (sc), consisting of bimodal discrete hard spheres, and the transition to amorphous packing is studied. First, the random close packing (rcp) fraction of binary mixtures of amorphously packed spheres is recapitulated. Next, the packing of a binary mixture of hard spheres in randomly disordered cubic structures is analyzed, resulting in original analytical expressions for the unit cell volume and the packing fraction, and which are also valid for the other five crystal systems. The bimodal fcc lattice parameter appears to be in close agreement with empirical hard sphere data from literature, and this parameter could be used to distinguish the size mismatch effect from all other effects in distorted binary lattices of materials. Here, as a first model application, bimodal amorphous and crystalline fcc/bcc packing fractions are combined, yielding the optimum packing configuration, which depends on mixture composition and diameter ratio only. Maps of the closest packing mode are established and applied to colloidal mixtures of polydisperse spheres and to binary alloys of bcc, fcc, and hcp metals. The extensive comparison between the analytical expressions derived here and the published numerical and empirical data yields good agreement. Hence, it is seen that basic space-filling theories on “simple” noninteracting hard spheres are a valuable tool for the study of crystalline materials.
An integrated modular approach for Visual Analytic Systems in Electronic Health Records
Directory of Open Access Journals (Sweden)
Muhammad Sheraz Arshad Malik
2012-09-01
Full Text Available Latest visual analytic tools help physicians to visualize temporal data in regards to medical health records. Existing systems lack vast support in the generalized collaboration, a single user-centered and task based design for Electronic Health Records (EHR. Already existing frameworks are unable to mentor the interface gaps due to problems like complexity of data sets, increased temporal information density and no support to live databases. These are significant reasons for a single model to comply the end user requirements. We propose an integrated model termed as CARE 1.0 as a future Visual analytic process model for resolving these kinds of issues based on mix method studies. This will base on different disciplines of HCI, Statistics as well as Computer Sciences. This proposed model encompasses the cognitive behavioral requirements of its stake holder’s i.e. physicians, database administrators and visualization designers. It helps in presenting a more generalized and detailed visualization for desired medical data sets.
Directory of Open Access Journals (Sweden)
Sulaimon Olanrewaju Adebiyi
2015-10-01
Full Text Available This paper describes the application of Analytic Hierarchy Process (AHP for unraveling customers’ motivation for churn of telecommunication network in Nigeria. By identifying, modeling and measuring of customers` churn motivations across four mobile telecommunication service providers in Nigeria. AHP was used to design a hierarchical model of seven criteria for customers` churning of network and investigates the relative priorities of the criteria through a pairwise comparison. The questionnaire were administered through convenient sampling to 480 mobile telecommunication customers and was completed and returned by 438 mobile phone subscribers in Lagos state, Nigeria, but only 408 copies were useful for the analysis of this study. The result shows that six out of the seven criteria have weight above 10% in their individual contribution to motivating customer churn behavior in the Nigeria telecommunication industry. The inefficient data/ internet plan criterion has the highest weight of 18.81% relative to the churn decision. Thus, AHP effectively supported modeling and analyzing subscribers` motivation toward good marketing decision for both the individual and the organization. It helps in developing an analytic and intelligible framework of decision-making on complex problem of customer churn in an emerging market like Nigeria
Optimal diffusion MRI acquisition for fiber orientation density estimation: an analytic approach.
White, Nathan S; Dale, Anders M
2009-11-01
An important challenge in the design of diffusion MRI experiments is how to optimize statistical efficiency, i.e., the accuracy with which parameters can be estimated from the diffusion data in a given amount of imaging time. In model-based spherical deconvolution analysis, the quantity of interest is the fiber orientation density (FOD). Here, we demonstrate how the spherical harmonics (SH) can be used to form an explicit analytic expression for the efficiency of the minimum variance (maximally efficient) linear unbiased estimator of the FOD. Using this expression, we calculate optimal b-values for maximum FOD estimation efficiency with SH expansion orders of L = 2, 4, 6, and 8 to be approximately b = 1,500, 3,000, 4,600, and 6,200 s/mm(2), respectively. However, the arrangement of diffusion directions and scanner-specific hardware limitations also play a role in determining the realizable efficiency of the FOD estimator that can be achieved in practice. We show how some commonly used methods for selecting diffusion directions are sometimes inefficient, and propose a new method for selecting diffusion directions in MRI based on maximizing the statistical efficiency. We further demonstrate how scanner-specific hardware limitations generally lead to optimal b-values that are slightly lower than the ideal b-values. In summary, the analytic expression for the statistical efficiency of the unbiased FOD estimator provides important insight into the fundamental tradeoff between angular resolution, b-value, and FOD estimation accuracy.
Guided Wave Based Crack Detection in the Rivet Hole Using Global Analytical with Local FEM Approach
Directory of Open Access Journals (Sweden)
Md Yeasin Bhuiyan
2016-07-01
Full Text Available In this article, ultrasonic guided wave propagation and interaction with the rivet hole cracks has been formulated using closed-form analytical solution while the local damage interaction, scattering, and mode conversion have been obtained from finite element analysis. The rivet hole cracks (damage in the plate structure gives rise to the non-axisymmetric scattering of Lamb wave, as well as shear horizontal (SH wave, although the incident Lamb wave source (primary source is axisymmetric. The damage in the plate acts as a non-axisymmetric secondary source of Lamb wave and SH wave. The scattering of Lamb and SH waves are captured using wave damage interaction coefficient (WDIC. The scatter cubes of complex-valued WDIC are formed that can describe the 3D interaction (frequency, incident direction, and azimuth direction of Lamb waves with the damage. The scatter cubes are fed into the exact analytical framework to produce the time domain signal. This analysis enables us to obtain the optimum design parameters for better detection of the cracks in a multiple-rivet-hole problem. The optimum parameters provide the guideline of the design of the sensor installation to obtain the most noticeable signals that represent the presence of cracks in the rivet hole.
An analysis of beam parameters on proton-acoustic waves through an analytic approach.
Aytac Kipergil, Esra; Erkol, Hakan; Kaya, Serhat; Gulsen, Gultekin; Unlu, Mehmet
2017-03-02
It has been reported that acoustic waves are generated when a high energy pulsed proton beam is deposited in a small volume within tissue. One possible application of the proton induced acoustics is to get a real-time feedback for intratreatment adjustments by monitoring such acoustic waves. High spatial resolution in ultrasound imaging may reduce proton range uncertainty. Thus, it is crucial to understand the dependence of the acoustic waves on the proton beam characteristics. In this manuscript, firstly, an analytic solution to the proton induced acoustic wave is presented to reveal the dependence of signal on beam parameters, and then combined with an analytic approximation of the Bragg curve. The influence of the beam energy, pulse duration, and beam diameter variation on the acoustic waveform are investigated. Further analysis is performed regarding the Fourier decomposition of proton-acoustic signals. Our results show that smaller spill time of proton beam upsurges the amplitude of acoustic wave for constant number of protons, and hence beneficial for dose monitoring. The increase in the energy of each individual proton in the beam leads to spatial broadening of the Bragg curve, which also yields acoustic waves of greater amplitude. The pulse duration and the beam width of the proton beam do not affect the central frequency of the acoustic wave, but they change the amplitude of the spectral components.
An analytical model of the heat of chemisorption: A perturbation LCAO MO approach
Shustorovich, Evgeny
1982-11-01
An analytical LCAO MO perturbation model has been developed for treating the heat of chemisorption Q of an adsorbate A monolayer on a transition metal M film. The model combines parameters of the metal band (the Fermi level E F, band width W = W occ + W vac, the d occupancy N d, density of states n(ɛ), etc.) with those of the local A-M interactions (the adorbital energy ɛ A, off-diagonal matrix elements βAM, etc.). The major cases of A's having lone pair, singly occupied, and vacant adorbitals have been considered, and the analytical expressions for Q as well as some numerical estimations are presented. The relative values of Q seem to be crucially dependent on the ratio β/( ɛA - E F). The Q vs. N d plots for the donor and radical A's are rather flat, typically Q decreasing monotonically as N d increases, but for the acceptor A's the plots are very parameter dependent and show a variety of trends. The results obtained agree with straightforward computations and (scarce) experimental data.
Quantum state engineering and reconstruction in cavity QED. An analytical approach
Energy Technology Data Exchange (ETDEWEB)
Lougovski, P.
2004-09-25
The models of a strongly-driven micromaser and a one-atom laser are developed. Their analytical solutions are obtained by means of phase space techniques. It is shown how to exploit the model of a one-atom laser for simultaneous generation and monitoring of the decoherence of the atom-field ''Schroedinger cat'' states. The similar machinery applied to the problem of the generation of the maximally-entangled states of two atoms placed inside an optical cavity permits its analytical solution. The steady-state solution of the problem exhibits a structure in which the two-atom maximally-entangled state correlates with the vacuum state of the cavity. As a consequence, it is demonstrated that the atomic maximally-entangled state, depending on a coupling regime, can be produced via a single or a sequence of no-photon measurements. The question of the implementation of a quantum memory device using a dispersive interaction between the collective internal ground state of an atomic ensemble and two orthogonal modes of a cavity is addressed. The problem of quantum state reconstruction in the context of cavity quantum electrodynamics is considered. The optimal operational definition of the Wigner function of a cavity field is worked out. It is based on the Fresnel transform of the atomic inversion of a probe atom. The general integral transformation for the Wigner function reconstruction of a particle in an arbitrary symmetric potential is derived.
Turnheim, Bruno; Berkhout, Frans; Geels, Frank; Hof, Andries|info:eu-repo/dai/nl/240412397; McMeekin, Andy; Nykvist, Björn; van Vuuren, Detlef|info:eu-repo/dai/nl/11522016X
2015-01-01
The paper sets out a proposal for bridging and linking three approaches to the analysis of transitions to sustainable and low-carbon societies: quantitative systems modelling; socio-technical transition analysis; and initiative-based learning. We argue that each of these approaches presents a
Wright, D. J.; Raad, M.; Hoel, E.; Park, M.; Mollenkopf, A.; Trujillo, R.
2016-12-01
Introduced is a new approach for processing spatiotemporal big data by leveraging distributed analytics and storage. A suite of temporally-aware analysis tools summarizes data nearby or within variable windows, aggregates points (e.g., for various sensor observations or vessel positions), reconstructs time-enabled points into tracks (e.g., for mapping and visualizing storm tracks), joins features (e.g., to find associations between features based on attributes, spatial relationships, temporal relationships or all three simultaneously), calculates point densities, finds hot spots (e.g., in species distributions), and creates space-time slices and cubes (e.g., in microweather applications with temperature, humidity, and pressure, or within human mobility studies). These "feature geo analytics" tools run in both batch and streaming spatial analysis mode as distributed computations across a cluster of servers on typical "big" data sets, where static data exist in traditional geospatial formats (e.g., shapefile) locally on a disk or file share, attached as static spatiotemporal big data stores, or streamed in near-real-time. In other words, the approach registers large datasets or data stores with ArcGIS Server, then distributes analysis across a cluster of machines for parallel processing. Several brief use cases will be highlighted based on a 16-node server cluster at 14 Gb RAM per node, allowing, for example, the buffering of over 8 million points or thousands of polygons in 1 minute. The approach is "hybrid" in that ArcGIS Server integrates open-source big data frameworks such as Apache Hadoop and Apache Spark on the cluster in order to run the analytics. In addition, the user may devise and connect custom open-source interfaces and tools developed in Python or Python Notebooks; the common denominator being the familiar REST API.
Institute of Scientific and Technical Information of China (English)
余永亮; 童秉纲; 马晖扬
2003-01-01
Numerous studies on the aerodynamics of insect wing flapping were carried out on different approaches of flight investigations, model experiments, and numerical simulations, but the theoretical modeling remains to be explored. In the present paper, an analytic approach is presented to model the flow interactions of wing flapping in air for small insects with the surrounding flow fields being highly unsteady and highly viscous. The model of wing flapping is a 2-D flat plate, which makes plunging and pitching oscillations as well as quick rotations reversing its positions of leading and trailing edges, respectively, during stroke reversals. It contains three simplified aerodynamic assumptions:(i) unsteady potential flow; (ii) discrete vortices shed from both leading and trailing edges of the wing; (iii) Kutta conditions applied at both edges. Then the problem is reduced to the solution of the unsteady Laplace equation, by using distributed singularities, i.e., sources/sinks, and vortices in the field. To validate the present physical model and analytic method proposed via benchmark examples, two elemental motions in wing flapping and a case of whole flapping cycles are analyzed,and the predicted results agree well with available experimental and numerical data. This verifies that the present analytical approach may give qualitatively correct and quantitatively reasonable results.Furthermore, the total fluid-dynamic force in the present method can be decomposed into three parts:one due to the added inertial (or mass) effect, the other and the third due to the induction of vortices shed from the leading- and the trailing-edge and their images respectively, and this helps to reveal the flow control mechanisms in insect wing flapping.
Lin, Yi-Hui; Lu, Chi-Yu; Jiang, Shiuh-Jen; Hsiao, Wen-Yao; Cheng, Hui-Ling; Chen, Yen-Ling
2015-10-01
The operating parameters that affect the performance of the online preconcentration technique "analyte focusing by micelle collapse-MEKC (AFMC-MEKC)" were examined using a multivariate approach involving experimental design to determine the sunscreen agents in cosmetics. Compared to the single-variable approach, the advantage of the multivariate approach was that many factors could be investigated simultaneously to obtain the best separation condition. A fractional factorial design was used to identify the fewest significant factors in the central composite design (cCD). The cCD was adopted for evaluating the location of the minimum or maximum response in this study. The influences of the experimental variables on the response were investigated by applying a chromatographic exponential function. The optimized condition and the relationship between the experimental variables were acquired using the JMP software. The ANOVA analysis indicated that the Tris pH value, SDS concentration, and ethanol percentage influenced the separation quality and significantly contributed to the model. The optimized condition of the running buffer was 10 mM Tris buffer (pH 9.5) containing 60 mM SDS, 7 mM γ-CD, and 20% v/v ethanol. The sample was prepared in 100 mM Tris buffer (pH 9.0) containing 7.5 mM SDS and 20% v/v ethanol. The SDS concentration in the sample matrix was slightly greater than the CMC value that makes the micelle be easily collapsed and the analytes be accumulated in the capillary. In addition, sunscreen agents in cosmetics after 1000-fold dilution were successfully determined by AFMC-MEKC. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
A Factor Analytic Study of the Beck Depression Inventory for Female College Students.
Hedl, John J., Jr.
Previous factor studies of the Beck Depression Inventory (BDI) have not analyzed the item data as a function of sex, or reported more than one factor solution. To further study the factor structure of the BDI, items were factor analyzed and multiple solutions were examined for simple structure, parsimony, and psychological meaningfulness. A sample…
A New Rational Algebraic Approach to Find Exact Analytical Solutions to a (2+1)-Dimensional System
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
In this paper, we present a new rational algebraic approach to uniformly construct a series of exact analytical solutions for nonlinear partial differential equations. Compared with most existing tanh methods and other sophisticated methods, the proposed method not only recovers some known solutions, but also finds some new and general solutions.The solutions obtained in this paper include rational form triangular periodic wave solutions, solitary wave solutions,and elliptic doubly periodic wave solutions. The efficiency of the method can be demonstrated on (2+1)-dimensional dispersive long-wave equation.
Institute of Scientific and Technical Information of China (English)
SANG Hong-Yi; LI Zhi-Yuan; GU Ben-Yuan
2005-01-01
@@ Defect modes in one-dimensional photonic crystals (PCs) can be readily detected from the solution of the transmission spectra via the standard transfer-matrix method. We adopt an analytic Bloch-mode approach to examine this problem in terms of eigenmode solutions and investigate the dispersion behaviour of localized defect modes supported by a defect layer sandwiched within two symmetric semi-infinite PCs that are made from multiple constituents. The results show that the number of defect modes grows when the dielectric constant and width of the defect layer increase.
The earrings of Pancas treasure: Analytical study by X-ray based techniques – A first approach
Energy Technology Data Exchange (ETDEWEB)
Tissot, I., E-mail: isabel.tissot@archeofactu.pt [Archeofactu – Rua do Cerrado das Oliveiras, No. 14, 2°Dto., 2610-035 Alfragide (Portugal); Tissot, M., E-mail: matthias.tissot@archeofactu.pt [Archeofactu – Rua do Cerrado das Oliveiras, No. 14, 2°Dto., 2610-035 Alfragide (Portugal); Museu Nacional de Arqueologia – Praça do Império, 1400-206 Lisboa (Portugal); Manso, M., E-mail: marta974@gmail.com [Centro de Física Atómica da Universidade de Lisboa, Av., Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); Alves, L.C., E-mail: luisa@cii.fc.ul.pt [IST/ITN, Univ. Técnica de Lisboa, E.N. 10, UFA-LFI, 2686-953 Sacavém (Portugal); Barreiros, M.A., E-mail: alexandra.barreiros@lneg.pt [LNEG, I.P., Estrada do Paço do Lumiar 22, 1649-038 Lisboa (Portugal); Marcelo, T., E-mail: teresa.marcelo@lneg.pt [LNEG, I.P., Estrada do Paço do Lumiar 22, 1649-038 Lisboa (Portugal); Carvalho, M.L., E-mail: lcalves@itn.pt [Centro de Física Atómica da Universidade de Lisboa, Av., Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); Corregidor, V., E-mail: vicky.corregidor@itn.pt [IST/ITN, Univ. Técnica de Lisboa, E.N. 10, UFA-LFI, 2686-953 Sacavém (Portugal); Guerra, M.F., E-mail: maria.guerra@culture.gouv.fr [Centre de Recherche et de Restauration des Musées de France and UMR8220 CNRS - 14, quai François Mitterrand, 75001 Paris (France)
2013-07-01
The development of new metallurgical technologies in the Iberian Peninsula during the Iron Age is well represented by the 10 gold earrings from the treasure of Pancas. This work presents a first approach to the analytical study of these earrings and contributes to the construction of a typological evolution of the Iberian earrings. The manufacture techniques and the alloys composition were studied with three complementary X-ray spectroscopy techniques: portable EDXRF, μ-PIXE and SEM–EDS. The results were compared with earrings from the same and previous periods.
Xu, Tianhua
2016-01-01
The analytical study on the carrier phase estimation (CPE) approaches, involving a one-tap normalized least-mean-square (NLMS) algorithm, a block-wise average (BWA) algorithm, and a Viterbi-Viterbi (VV) algorithm has been investigated in the long-haul high-speed n-level phase shift keying (n-PSK) coherent optical fiber communication systems. The close-form predictions for the bit-error-rate (BER) performance have been derived and analyzed by considering both the intrinsic laser phase noise and the equalization enhanced phase noise (EEPN).
Genre Analytic Approach in ESP Research%ESP研究中的语类分析路径
Institute of Scientific and Technical Information of China (English)
庞继贤; 程乐
2012-01-01
ESP是以特定学习者的特定交际需求为指向的一种教学路径。从语言分析角度看,ESP重在探究不同专业话语社团语言运用的特定性。语类理论重在辨析不同语类语篇的交际目的以及与此相关的结构和语言体现特点,这与ESP的特定性直接相关。近年来,ESP领域中语类分析有三个研究焦点：语类的整体结构与语言特点;语类资源、功能多样性及文化语境;语类集、篇际互文性与批评语类分析。语类分析并非仅仅局限于对语篇的语步结构分析,当前ESP的语类分析已是一种跨学科、多维度、多视角、带有批评性的研究;语类的观念和语类分析为ESP理论建构和教学实践提供了强有力的实证理据。%English for Specific Purposes(ESP) is a teaching strategy which aims to meet the specific communicative needs of language learners.From the perspective of linguistic analysis,ESP focuses on language use in specialist discourse communities to which prospective language users belong.The genre-analytic approach,with its power to clarify the communicative purposes and linguistic features of genre texts,supports the characteristic feature of specificity in ESP.This paper reviews the three main focuses of genre-analytic research in ESP literature: 1) generic integrity and linguistic features,2) generic resources,functional variation and cultural contexts,and 3) genre sets,interdiscursivity and critical genre analysis.The analysis indicates that the genre approach is not limited to move analysis as is generally understood,and that the genre-analytic approach in ESP has now become a cross disciplinary,multi dimensional,multi perspective and critical analysis of discourse.The paper also illuminates how the genre analytic approach has provided strong empirical support for the development of theory and practice in ESP.
DEFF Research Database (Denmark)
Ryberg, Thomas; Dirckinck-Holmfeld, Lone
2008-01-01
This paper sets out to problematize generational categories such as ‘Power Users’ or ‘New Millennium Learners’ by discussing these in the light of recent research on youth and ICT. We then suggest analytic and conceptual pathways to engage in more critical and empirically founded studies of young...... of understanding learning as a process of patchworking and discusses how we might use this to understand young people’s learning with digital media....... people’s learning in technology and media-rich settings. Based on a study of a group of young ‘Power Users’ it is argued, that conceptualising and analysing learning as a process of patchworking can enhance our knowledge of young people’s learning in such settings. We argue that the analytical approach...... gives us ways of critically investigating young people’s learning in technology and media-rich settings, and study if these are processes of critical, reflexive enquiry where resources are creatively re-appropriated. With departure in an analytical example the paper presents the proposed metaphor...
Tuzkaya, Gülfem; Onüt, Semih; Tuzkaya, Umut R; Gülsün, Bahadir
2008-09-01
Locating an undesirable facility is a sophisticated problem, for the evaluation procedures involve several objectives and the solution to the problem calls for some compromises to be made between probable conflicting criteria. This paper addresses the problem of undesirable facility location selection using the analytic network process (ANP), a multi-criteria decision-making technique. The ANP technique enables us to consider both qualitative and quantitative criteria as well as the interdependencies and feedbacks. A number of criteria (benefits, opportunities, costs and risks) and their sub-criteria are considered for siting a new facility with which this study has dealt. The questions of what criteria would be considered and what the interdependencies between these criteria and their weights would be were discussed and determined via interviews with some competent authorities of the Istanbul Municipality and of two environmental organizations. Four representative locations were evaluated and the most convenient one was selected. This was followed by the sensitivity analyses of the results.
DEFF Research Database (Denmark)
Kushch, V.I.; Shmegera, S.V.; Mishnaevsky, Leon
2011-01-01
Two micromechanical, representative unit cell type models of fiber reinforced composite (FRC) are applied to simulate explicitly onset and accumulation of scattered local damage in the form of interface debonding. The first model is based on the analytical, multipole expansion type solution...... of the multiple inclusion problem by means of complex potentials. The second, finite element model of FRC is based on the cohesive zone model of interface. Simulation of progressive debonding in FRC using the many-fiber models of composite has been performed. The advantageous features and applicability areas...... of both models are discussed. It has been shown that the developed models provide detailed analysis of the progressive debonding phenomena including the interface crack cluster formation, overall stiffness reduction and induced anisotropy of the effective elastic moduli of composite....
The evolution of stable magnetic fields in stars: an analytical approach
Mestel, Leon; Moss, David
2010-07-01
The absence of a rigorous proof of the existence of dynamically stable, large-scale magnetic fields in radiative stars has been for many years a missing element in the fossil field theory for the magnetic Ap/Bp stars. Recent numerical simulations, by Braithwaite & Spruit and Braithwaite & Nordlund, have largely filled this gap, demonstrating convincingly that coherent global scale fields can survive for times of the order of the main-sequence lifetimes of A stars. These dynamically stable configurations take the form of magnetic tori, with linked poloidal and toroidal fields, that slowly rise towards the stellar surface. This paper studies a simple analytical model of such a torus, designed to elucidate the physical processes that govern its evolution. It is found that one-dimensional numerical calculations reproduce some key features of the numerical simulations, with radiative heat transfer, Archimedes' principle, Lorentz force and Ohmic decay all playing significant roles.
Analytical parametrization and shape classification of anomalous HH production in EFT approach
Carvalho Antunes De Oliveira, Alexandra; De Castro Manzano, Pablo; Dorigo, Tommaso; Goertz, Florian; Gouzevitch, Maxime; Tosi, Mia
2016-01-01
In this document we study the effect of anomalous Higgs boson couplings on non-resonant pair production of Higgs bosons (HH) at the LHC. We explore the space of the five parameters $\\kappa_\\lambda$, $\\kappa_t$, $c_2$, $c_{g}$, and $c_{2g}$ in terms of the corresponding kinematics of the final state, and describe a suggested partition of the space into a limited number of regions featuring similar phenomenology in the kinematics of HH final state, along with a corresponding set of representative benchmark points. We also provide an analytical parametrization of the cross-section modifications that the variation of anomalous couplings produces with respect to standard model HH production along with a recipe to translate our results into other parameter-space bases. Finally, we provide a preliminary analysis of variations in the topology of the final state within each region based on recent LHC results.
An Improved Analytical Approach to Determine the Explosive Effects of Flammable Gas-Air Mixtures
Energy Technology Data Exchange (ETDEWEB)
Yang, J M
2005-11-10
The U.S. Department of Energy (DOE) Complex includes many sites and laboratories that store quantities of low-level, solid nuclear waste in drums and other types of shipping containers. The drums may be stored for long periods of time prior to being transported and final dispositioning. Based on the radioactivity (e.g., Pu{sup 239} equivalent), chemical nature (e.g. volatile organic compounds) and other characteristics of the stored waste, flammable gases may evolve. Documented safety analyses (DSAs) for storage of these drums must address storage and safety management issues to protect workers, the general public, and the environment. This paper discusses an improved analytical method for determining the explosion effects flammable gas-air mixtures as well as the subsequent accident phenomenology.
Directory of Open Access Journals (Sweden)
Srinivas Bulusu
2016-06-01
Full Text Available An operational consistency model for real-time dynamic traffic assignment (DTA applications seeks to correct the time-dependent path assignment within a rolling horizon scheme. This study extends an existing consistency framework to develop a hierarchy for the time-dependent path set based upon their relative importance to ensuring consistency. Using the analytic hierarchy process, the eigenvalue associated with a path is identified as the parameter which enables the rank ordering of paths. The ability to identify a subset of dominant paths relative to enhancing consistency enhances the computational viability of the consistency framework for real-time implementation and has significant practical implications. Additionally, it provides insights on the complex dynamics that are inherent to the operational consistency problem.
Energy Technology Data Exchange (ETDEWEB)
Brockmann, T.; Lammering, R. [Universitaet der Bundeswehr, Hamburg (Germany). Inst. fuer Mechanik
2001-07-01
In the context of adaptive systems, the technology of piezoelectric fiber composites with its capabilities for high-speed actuation and the beneficial effects of tailorable anisotropy is of great interest for structurally integrated vibration suppression and acoustic control. In order to study the interaction between active and load carrying functionalities and to analyze the influence of the diverse parameters, an analytic model containing all major characteristics from the micromechanics to the structural mechanics level is described. The effective electroelastic properties of a lamina with embedded continuous piezoceramic fibers exposed to an electric field in fiber direction are examined in the close-up investigation of a representative volume. With the aid of the classical lamination theory, extended by the internal actuation loads, such plies can be combined for the respective purpose. Finally, the active and passive properties of a single-cell closed cross-section beam with walls made from these laminated composites are derived. (orig.)
A Highly Accurate and Efficient Analytical Approach to Bridge Deck Free Vibration Analysis
Directory of Open Access Journals (Sweden)
D.J. Gorman
2000-01-01
Full Text Available The superposition method is employed to obtain an accurate analytical type solution for the free vibration frequencies and mode shapes of multi-span bridge decks. Free edge conditions are imposed on the long edges running in the direction of the deck. Inter-span support is of the simple (knife-edge type. The analysis is valid regardless of the number of spans or their individual lengths. Exact agreement is found when computed results are compared with known eigenvalues for bridge decks with all spans of equal length. Mode shapes and eigenvalues are presented for typical bridge decks of three and four span lengths. In each case torsional and non-torsional modes are studied.
Lie-Algebraic Approach for Pricing Zero-Coupon Bonds in Single-Factor Interest Rate Models
Directory of Open Access Journals (Sweden)
C. F. Lo
2013-01-01
Full Text Available The Lie-algebraic approach has been applied to solve the bond pricing problem in single-factor interest rate models. Four of the popular single-factor models, namely, the Vasicek model, Cox-Ingersoll-Ross model, double square-root model, and Ahn-Gao model, are investigated. By exploiting the dynamical symmetry of their bond pricing equations, analytical closed-form pricing formulae can be derived in a straightfoward manner. Time-varying model parameters could also be incorporated into the derivation of the bond price formulae, and this has the added advantage of allowing yield curves to be fitted. Furthermore, the Lie-algebraic approach can be easily extended to formulate new analytically tractable single-factor interest rate models.
A confirmatory factor analytical study of a servant leadership measure in South Africa
Directory of Open Access Journals (Sweden)
Bright Mahembe
2013-03-01
Full Text Available Orientation: Servant leadership is a value-based leadership practice that plays a critical role in team effectiveness and organisational success.Research purpose: The goal of the study was to validate the Servant Leadership Questionnaire(SLQ, which Barbuto and Wheeler developed, on a South African sample.Motivation for the study: The literature is replete with evidence of the role of follower focused leadership practices in improving team effectiveness, employee engagement and organisational success. We need to complement these efforts with psychometrically sound measuring instruments.Research design, approach and method: The authors drew a convenience sample of 288 school teachers from schools in the Western Cape Province of South Africa. They used the SLQ that Barbuto and Wheeler developed to measure servant leadership.Main findings: The authors found high levels of reliability for the sub-scales of the latent variables. They found good fit with the data for the measurement model of the five latent servant leadership dimensions (altruistic calling, persuasive mapping, emotional healing, wisdom and organisational stewardship through confirmatory factor analyses (CFA. They obtained reasonable fit for the first- and second-order servant leadership CFA. The authors concluded that the SLQ shows reasonable fit.Practical/managerial implications: The SLQ showed evidence of reliability and construct validity. It can contribute to the scientific selection and development of education leaders in South African schools.Contribution/value add: Servant leadership incorporates a service ethic that fosters participatory management, teacher development and team building. The department of education should increase team effectiveness in schools by selecting and developing servant leadership.
Analytical Approach to Ballistic Dispersion of Projectile Weapons Based on Variant Launch Velocity
2013-04-01
When a low coefficient of variation of 1% is used for vz0, through Monte Carlo simulation, a correction factor of 0.969 is needed in the elevation...feasible, the statistics of ach individual factor can be estimated with a few data points, ollowed by comprehensive Monte Carlo simulation for the cor...DEFENSE TECHNICAL (PDF) INFORMATION CTR DTIC OCA 8725 JOHN J KINGMAN RD STE 0944 FORT BELVOIR VA 22060-6218 1 DIRECTOR (PDF) US
Lin, Long-Ze; Harnly, James M.
2007-01-01
A screening method was developed for the systematic identification of glycosylated flavonoids and other phenolic compounds in plant food materials based on an initial, standard analytical method. This approach applies the same analytical scheme (aqueous methanol extraction, reverse phase liquid chromatographic separation, and diode array and mass spectrometric detection) to every sample and standard. This standard approach allows the cross-comparison of compounds in samples, standards, and pl...
Banchi, Leonardo; Ishizaki, Akihito; Giorda, Paolo
2013-01-01
In large photosynthetic chromophore-protein complexes not all chromophores are coupled strongly, and thus the situation is well described by formation of delocalized states in certain domains of strongly coupled chromophores. In order to describe excitation energy transfer among different domains without performing extensive numerical calculations,one of the most popular techniques is a generalization of Forster theory to multichromophoric aggregates (generalized Forster theory) proposed by Sumi [J.Phys.Chem.B,103,252(1999)] and Scholes and Fleming [J.Phys.Chem.B 104,1854(2000)]. The aim of this paper is twofold. In the first place, by means of analytic continuation and a time convolutionless quantum master equation approach, a theory of emission lineshape of multichromophoric systems or molecular aggregates is proposed. In the second place,a comprehensive framework that allows for a clear,compact and effective study of the multichromophoric approach in the full general version proposed by Jang, Newton and Si...
Starkov, Alexander S; Starkov, Ivan A
2013-12-01
We have proposed a new theoretical approach for the determination of the electric field distribution in the ferroelectric/dielectric system with the presence of the SPM tip. The initial statement of the model has only a numerical solution. To find an analytical solution of the problem, some assumptions are introduced: the domain wall thickness can be considered to be much smaller than the domain size, and we use a high ferroelectric dielectric permittivity. The developed approach allows us to obtain explicit formulas for the polarization and electric field intensity. We have calculated and then analyzed the tip capacitance as a function of the distance from the ferroelectric interface. Additionally, different forms of the SPM tip are considered. It is demonstrated that in the presence of charges at the domain, the results differ from those obtained with the widely used dielectric model by 30%.
Human factors systems approach to healthcare quality and patient safety
Carayon, Pascale; Wetterneck, Tosha B.; Rivera-Rodriguez, A. Joy; Hundt, Ann Schoofs; Hoonakker, Peter; Holden, Richard; Gurses, Ayse P.
2013-01-01
Human factors systems approaches are critical for improving healthcare quality and patient safety. The SEIPS (Systems Engineering Initiative for Patient Safety) model of work system and patient safety is a human factors systems approach that has been successfully applied in healthcare research and practice. Several research and practical applications of the SEIPS model are described. Important implications of the SEIPS model for healthcare system and process redesign are highlighted. Principles for redesigning healthcare systems using the SEIPS model are described. Balancing the work system and encouraging the active and adaptive role of workers are key principles for improving healthcare quality and patient safety. PMID:23845724
Trnka, Radek; Lačev, Alek; Balcar, Karel; Kuška, Martin; Tavel, Peter
2016-01-01
The widely accepted two-dimensional circumplex model of emotions posits that most instances of human emotional experience can be understood within the two general dimensions of valence and activation. Currently, this model is facing some criticism, because complex emotions in particular are hard to define within only these two general dimensions. The present theory-driven study introduces an innovative analytical approach working in a way other than the conventional, two-dimensional paradigm. The main goal was to map and project semantic emotion space in terms of mutual positions of various emotion prototypical categories. Participants (N = 187; 54.5% females) judged 16 discrete emotions in terms of valence, intensity, controllability and utility. The results revealed that these four dimensional input measures were uncorrelated. This implies that valence, intensity, controllability and utility represented clearly different qualities of discrete emotions in the judgments of the participants. Based on this data, we constructed a 3D hypercube-projection and compared it with various two-dimensional projections. This contrasting enabled us to detect several sources of bias when working with the traditional, two-dimensional analytical approach. Contrasting two-dimensional and three-dimensional projections revealed that the 2D models provided biased insights about how emotions are conceptually related to one another along multiple dimensions. The results of the present study point out the reductionist nature of the two-dimensional paradigm in the psychological theory of emotions and challenge the widely accepted circumplex model.
A Simple Analytical Approach to the Aeroelastic Stability Problem of Long-Span Cable-Stayed Bridges
Vairo, Giuseppe
2010-01-01
This paper deals with the aeroelastic stability problem of long-span cable-stayed bridges under an approaching crosswind flow. Starting from a continuous model of the fan-shaped bridge scheme with both H- or A-shaped towers, critical states of the coupled wind-structure system are identified by means of a variational formulation, accounting for torsional and flexural (vertical and lateral) bridge oscillations. The overall bridge dynamics is described by introducing simple mechanical systems with equivalent stiffness properties and, under the assumption of a prevailing truss-like bridge behavior, analytical estimates for dominant stiffness contributions are proposed. Several case studies are discussed and comparisons with experimental evidences as well as with available analytical and numerical results are presented. The proposed simplified approach proves to be consistent and effective for successfully capturing the main wind-bridge interaction mechanisms, and it could be considered as a useful engineering tool for the aeroelastic stability analysis of long-span cable-stayed bridges.
Thompson, Seonaid M; Craven, Rachel A; Nirmalan, Niroshini J; Harnden, Patricia; Selby, Peter J; Banks, Rosamonde E
2013-04-01
Formalin-fixed paraffin-embedded (FFPE) tissue samples represent a tremendous potential resource for biomarker discovery, with large numbers of samples in hospital pathology departments and links to clinical information. However, the cross-linking of proteins and nucleic acids by formalin fixation has hampered analysis and proteomic studies have been restricted to using frozen tissue, which is more limited in availability as it needs to be collected specifically for research. This means that rare disease subtypes cannot be studied easily. Recently, improved extraction techniques have enabled analysis of FFPE tissue by a number of proteomic techniques. As with all clinical samples, pre-analytical factors are likely to impact on the results obtained, although overlooked in many studies. The aim of this review is to discuss the various pre-analytical factors, which include warm and cold ischaemic time, size of sample, fixation duration and temperature, tissue processing conditions, length of storage of archival tissue and storage conditions, and to review the studies that have considered these factors in more detail. In those areas where investigations are few or non-existent, illustrative examples of the possible importance of specific factors have been drawn from studies using frozen tissue or from immunohistochemical studies of FFPE tissue. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Visual analytics for spatial clustering: using a heuristic approach for guided exploration.
Packer, Eli; Bak, Peter; Nikkilä, Mikko; Polishchuk, Valentin; Ship, Harold J
2013-12-01
We propose a novel approach of distance-based spatial clustering and contribute a heuristic computation of input parameters for guiding users in the search of interesting cluster constellations. We thereby combine computational geometry with interactive visualization into one coherent framework. Our approach entails displaying the results of the heuristics to users, as shown in Figure 1, providing a setting from which to start the exploration and data analysis. Addition interaction capabilities are available containing visual feedback for exploring further clustering options and is able to cope with noise in the data. We evaluate, and show the benefits of our approach on a sophisticated artificial dataset and demonstrate its usefulness on real-world data.
Stahl, Cynthia; Cimorelli, Alan
2013-01-01
Because controversy, conflict, and lawsuits frequently characterize US Environmental Protection Agency (USEPA) decisions, it is important that USEPA decision makers understand how to evaluate and then make decisions that have simultaneously science-based, social, and political implications. Air quality management is one category of multidimensional decision making at USEPA. The Philadelphia, Pennsylvania metropolitan area experiences unhealthy levels of ozone, fine particulate matter, and air toxics. Many ozone precursors are precursors for particulate matter and certain air toxics. Additionally, some precursors for particulate matter are air toxics. However, air quality management practices have typically evaluated these problems separately. This approach has led to the development of independent (and potentially counterproductive) implementation strategies. This is a methods article about the necessity and feasibility of using a clumsy approach on wicked problems, using an example case study. Air quality management in Philadelphia is a wicked problem. Wicked problems are those where stakeholders define or view the problem differently, there are many different ways to describe the problem (i.e., different dimensions or levels of abstraction), no efficient or optimal solutions exist, and they are often complicated by moral, political, or professional dimensions. The USEPA has developed the multicriteria integrated resource assessment (MIRA) decision analytic approach that engages stakeholder participation through transparency, transdisciplinary learning, and the explicit use of value sets; in other words, a clumsy approach. MIRA's approach to handling technical indicators, expert judgment, and stakeholder values makes it a potentially effective method for tackling wicked environmental problems.
Humanistic Approach and Affective Factors in Foreign Language Teaching
Institute of Scientific and Technical Information of China (English)
罗馨
2010-01-01
For a long time,Chinese EFL teaching has been following the teacher-centered model,which emphasizes the cognitive aspect but ignores the affective factors. So "emotional illiteracy" is a common phemenon and harmful to language learning and students' all-round development. This essay lays special stress on humanistic approach and analyzes the influence of some important affective factors on language learning,for the purpose of inviting teachers' attention to students' emotions in fulfilling their teaching task.
Factorization approach to superintegrable systems: Formalism and applications
Ballesteros, Á.; Herranz, F. J.; Kuru, Ş.; Negro, J.
2017-03-01
The factorization technique for superintegrable Hamiltonian systems is revisited and applied in order to obtain additional (higher-order) constants of the motion. In particular, the factorization approach to the classical anisotropic oscillator on the Euclidean plane is reviewed, and new classical (super) integrable anisotropic oscillators on the sphere are constructed. The Tremblay-Turbiner-Winternitz system on the Euclidean plane is also studied from this viewpoint.
Factorization approach to superintegrable systems: Formalism and applications
Energy Technology Data Exchange (ETDEWEB)
Ballesteros, Á., E-mail: angelb@ubu.es; Herranz, F. J., E-mail: fjherranz@ubu.es [Universidad de Burgos, Departamento de Física (Spain); Kuru, Ş., E-mail: kuru@science.ankara.edu.tr [Ankara University, Department of Physics, Faculty of Science (Turkey); Negro, J., E-mail: jnegro@fta.uva.es [Universidad de Valladolid, Departamento de Física Teórica, Atómica y Óptica (Spain)
2017-03-15
The factorization technique for superintegrable Hamiltonian systems is revisited and applied in order to obtain additional (higher-order) constants of the motion. In particular, the factorization approach to the classical anisotropic oscillator on the Euclidean plane is reviewed, and new classical (super) integrable anisotropic oscillators on the sphere are constructed. The Tremblay–Turbiner–Winternitz system on the Euclidean plane is also studied from this viewpoint.
VAET: A Visual Analytics Approach for E-Transactions Time-Series.
Xie, Cong; Chen, Wei; Huang, Xinxin; Hu, Yueqi; Barlowe, Scott; Yang, Jing
2014-12-01
Previous studies on E-transaction time-series have mainly focused on finding temporal trends of transaction behavior. Interesting transactions that are time-stamped and situation-relevant may easily be obscured in a large amount of information. This paper proposes a visual analytics system, Visual Analysis of E-transaction Time-Series (VAET), that allows the analysts to interactively explore large transaction datasets for insights about time-varying transactions. With a set of analyst-determined training samples, VAET automatically estimates the saliency of each transaction in a large time-series using a probabilistic decision tree learner. It provides an effective time-of-saliency (TOS) map where the analysts can explore a large number of transactions at different time granularities. Interesting transactions are further encoded with KnotLines, a compact visual representation that captures both the temporal variations and the contextual connection of transactions. The analysts can thus explore, select, and investigate knotlines of interest. A case study and user study with a real E-transactions dataset (26 million records) demonstrate the effectiveness of VAET.
Molinos-Senante, María; Gómez, Trinidad; Caballero, Rafael; Hernández-Sancho, Francesc; Sala-Garrido, Ramón
2015-11-01
The selection of the most appropriate wastewater treatment (WWT) technology is a complex problem since many alternatives are available and many criteria are involved in the decision-making process. To deal with this challenge, the analytic network process (ANP) is applied for the first time to rank a set of seven WWT technology set-ups for secondary treatment in small communities. A major advantage of ANP is that it incorporates interdependent relationships between elements. Results illustrated that extensive technologies, constructed wetlands and pond systems are the most preferred alternatives by WWT experts. The sensitivity analysis performed verified that the ranking of WWT alternatives is very stable since constructed wetlands are almost always placed in the first position. This paper showed that ANP analysis is suitable to deal with complex decision-making problems, such as the selection of the most appropriate WWT system contributing to better understand the multiple interdependences among elements involved in the assessment. Copyright © 2015 Elsevier B.V. All rights reserved.
Analytic approach to nonlinear hydrodynamic instabilities driven by time-dependent accelerations
Energy Technology Data Exchange (ETDEWEB)
Mikaelian, K O
2009-09-28
We extend our earlier model for Rayleigh-Taylor and Richtmyer-Meshkov instabilities to the more general class of hydrodynamic instabilities driven by a time-dependent acceleration g(t) . Explicit analytic solutions for linear as well as nonlinear amplitudes are obtained for several g(t)'s by solving a Schroedinger-like equation d{sup 2}{eta}/dt{sup 2} - g(t)kA{eta} = 0 where A is the Atwood number and k is the wavenumber of the perturbation amplitude {eta}(t). In our model a simple transformation k {yields} k{sub L} and A {yields} A{sub L} connects the linear to the nonlinear amplitudes: {eta}{sup nonlinear} (k,A) {approx} (1/k{sub L})ln{eta}{sup linear} (k{sub L}, A{sub L}). The model is found to be in very good agreement with direct numerical simulations. Bubble amplitudes for a variety of accelerations are seen to scale with s defined by s = {integral} {radical}g(t)dt, while spike amplitudes prefer scaling with displacement {Delta}x = {integral}[{integral}g(t)dt]dt.
Amendment to "Performance Analysis of the V-BLAST Algorithm: An Analytical Approach." [1
Loyka, Sergey
2008-01-01
An analytical technique for the outage and BER analysis of the nx2 V-BLAST algorithm with the optimal ordering has been presented in [1], including closed-form exact expressions for average BER and outage probabilities, and simple high-SNR approximations. The analysis in [1] is based on the following essential approximations: 1. The SNR was defined in terms of total after-projection signal and noise powers, and the BER was analyzed based on their ratio. This corresponds to a non-coherent (power-wise) equal-gain combining of both the signal and the noise, and it is not optimum since it does not provide the maximum output SNR. 2. The definition of the total after-projection noise power at each step ignored the fact that the after-projection noise vector had correlated components. 3. The after-combining noises at different steps (and hence the errors) were implicitly assumed to be independent of each other. Under non-coherent equal-gain combining, that is not the case. It turns out that the results in [1] hold a...
An Analytical/Computational Approach to the Effect of Roughness on Erosion: Global and Local Angles
Lasa, A.; Canik, J. M.; Unterberg, E. A.; Rapp, J.; Chrobak, C.; Stangeby, P. C.
2016-10-01
Plasma-material interactions lead to erosion of plasma facing surfaces, limiting component lifetime, and leading to impurity production and plasma contamination. Surface erosion depends, among other parameters, on the impact angle, which is determined both by local plasma conditions and surface morphology. For rough surfaces (O(μ m)), the ``local'' particle impact angle can differ significantly from the ``global'' impact angle defined by the average surface contour. So far, studies targeted at bridging these local and global angles have been of interpretative focus, aiming to model and understand erosion of naturally occurring surfaces following their exposure to plasma. Here, a more general study of how surface morphology impacts erosion is undertaken by deriving impact angle and density distributions for analytically described surfaces, while systematically varying the ``global angle'' and degree of roughness. These distributions are used to derive spatially resolved erosion yields, as well as estimating the impact of roughness on the total erosion. Surfaces of interest also include ones intentionally sculpted to control material surface migration. This work is supported by the US DOE under contract DE-AC05-00OR22725.
Transient Heat Conduction in a Wall Exposed to a Fire: an Analytic Approach
Casano, G.; Piva, S.
2017-01-01
Fire safety engineering requires a detailed understanding of fire behaviour and of its effects on structures and people. Currently, advanced numerical codes for the prediction of the fire behaviour are available. However, they often require heavy calculations and long times. In this context analytical solutions can be useful for a fast analysis of simplified schematizations. It allows a more effective final utilization of the advanced fire codes. In this contribution, for a separation wall exposed to a fire the temperature history is analysed of the unexposed wall surface. Due to the limitations of the model, the temperature in the fire room changes stepwise, with a final value typical of a post-flashover condition. Nevertheless, with an appropriate choice of the heat transfer coefficient, the thermal action on the surface exposed to fire becomes that due to a fire following the standard temperature-time curve. The solution is then obtained by applying the separation of variables to the heat conduction equation. The problem is made dimensionless and the results are analysed in order to validate their significance. This simplified model allows to obtain useful information on the magnitude of the temperature reached.
Magrini, Donata; Bracci, Susanna; Cantisani, Emma; Conti, Claudia; Rava, Antonio; Sansonetti, Antonio; Shank, Will; Colombini, MariaPerla
2017-02-01
Samples from Keith Haring's wall painting of the Necker Children Hospital in Paris were studied by a multi-analytical protocol. X-ray fluorescence (XRF), powder X-ray diffraction (XRDP), Electron microscope (SEM-EDS), Infrared and Raman spectroscopy (μ-FT-IR and μ-Raman) measurements were performed in order to characterize the materials and to identify the art technique used to produce this contemporary work. Materials from the mural suffered from severe detachments of materials and several fragments were found on the ground beneath. Some of these fragments, which were representative of the whole palette and stratigraphic sequence, were collected and studied. The fragments were sufficiently large to enable non-invasive measurements to be performed in order to characterize the materials. A comparison of the data of the techniques applied revealed that Haring's palette was composed of organic pigments such as Naphtol red, phthalocyanine blue and green and Hansa yellow, in accordance with those used previously by the artist in other painted murals.
Analytical approaches to identify potential migrants in polyester-polyurethane can coatings.
Louise Bradley, Emma; Driffield, Malcolm; Guthrie, James; Harmer, Nick; Thomas Oldring, Peter Kenneth; Castle, Laurence
2009-12-01
The safety of a polyester-polyurethane can coating has been assessed using a suite of complementary analytical methods to identify and estimate the concentrations of potential chemical migrants. The polyester was based on phthalic acids and aliphatic diols. The polyisocyanate cross-linking agent was 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethyl cyclohexane homopolymer (IPDI) blocked with methylethylketone oxime (MEKO) to make a one-part formulation. The overall migrate, obtained using solvent extraction of cured films, comprised almost completely of 12 cyclic and one linear polyester oligomer up to molecular weight 800 and containing up to six monomer units. These 13 oligomers covered a total of 28 isomeric forms. Other minor components detected were plasticisers and surfactants as well as impurities present in the starting materials. There was no detectable residue of either the blocked isocyanate (<0.01 microg/dm(2)) used as the starting substance or the unblocked isocyanate (<0.02 microg/dm(2)). The level of extractable IPDI was used as an indicator of the completeness of cure in experimental coatings. These studies revealed that there was an influence of time, temperature and catalyst content. Polymerisation was also influenced by the additives used and by the ageing of the wet coating formulation over several months. These studies allow parameters to be specified to ensure that commercial production coatings receive a full cure giving low migration characteristics.
Analytical parametrization and shape classification of anomalous HH production in the EFT approach
Carvalho, Alexandra; Manzano, Pablo de Castro; Dorigo, Tommaso; Goertz, Florian; Gouzevich, Maxime; Tosi, Mia
2016-01-01
In this document we study the effect of anomalous Higgs boson couplings on non-resonant pair production of Higgs bosons ($HH$) at the LHC. We explore the space of the five parameters $\\kappa_{\\lambda}$, $\\kappa_{t}$, $c_2$, $c_g$, and $c_{2g}$ in terms of the corresponding kinematics of the final state, and describe a partition of the space into a limited number of regions featuring similar phenomenology in the kinematics of $HH$ final state. We call clusters the sets of points belonging to the same region; to each cluster corresponds a representative point which we call a benchmark. We discuss a possible technique to estimate the sensitivity of an experimental search to the kinematical differences between the phenomenology of the benchmark points and the rest of the parameter space contained in the corresponding cluster. We also provide an analytical parametrization of the cross-section modifications that the variation of anomalous couplings produces with respect to standard model $HH$ production along with ...
Directory of Open Access Journals (Sweden)
Mr. Yogesh Rai
2011-09-01
Full Text Available Many methods have been researched to prolong sensor network lifetime using mobile technologies. In the mobile sink research, there are the track based methods and the anchor points based methods as representative operation methods for mobile sinks. However, the existing methods decrease Quality of Service (QoS and lead the routing hotspot in the vicinity of the mobile sink. In large scale wireless sensor networks, clustering is an effective technique for the purpose of improving the utilization of limited energy and prolonging the network lifetime. However, the problem of unbalanced energy dissipation exists in the multi-hop clustering model, where the cluster heads closer to the sink have to relay heavier traffic and consume more energy than farther nodes. In this paper we analyze several aspects based on the optimal clustering architecture for maximizing lifetime for large scale wireless sensor network. We also provide some analytical concepts for energy-aware head rotation and routing protocols to further balance the energy consumption among all nodes.
On the evolution of primordial gravitational waves: a semi-analytic detailed approach
Soares-Santos, M
2006-01-01
A cosmological gravitational wave background resulting from space-time quantum perturbations at energy scales of $\\sim 10^{15}$GeV is expected as a consequence of the general relativity theory in the context of the standard cosmological model. Initial conditions %for the problem are determined during the inflationary (de Sitter) era, at $z \\gtrsim 10^{25} $. A semi-analytic method was developed to evolve the system up to the present with no need of simplifying approximations as the thin-horizon (super-adiabatic) or the instantaneous transitions between the successive phases of domain of the different cosmic fluids. The accuracy of such assumptions, broadly employed in the literature, is put in check. Since the physical nature of the fluid (known as dark energy) leading to the accelerated expansion observed in the recent Universe is still uncertain, four categories of models were analyzed: cosmological constant, X-fluid (phantom or not), generalized Chaplygin gas and (a parametric form of) quintessence. The re...
Zednik, S.
2015-12-01
Recent data publication practices have made increasing amounts of diverse datasets available online for the general research community to explore and integrate. Even with the abundance of data online, relevant data discovery and successful integration is still highly dependent upon the data being published with well-formed and understandable metadata. Tagging a dataset with well-known or controlled community terms is a common mechanism to indicate the intended purpose, subject matter, or other relevant facts of a dataset, however controlled domain terminology can be difficult for cross-domain researchers to interpret and leverage. It is also a challenge for integration portals to successfully provide cross-domain search capabilities over data holdings described using many different controlled vocabularies. Mappings between controlled vocabularies can be challenging because communities frequently develop specialized terminologies and have highly specific and contextual usages of common words. Despite this specificity it is highly desirable to produce cross-domain mappings to support data integration. In this contribution we evaluate the applicability of several data analytic techniques for the purpose of generating mappings between hierarchies of controlled science terms. We hope our efforts initiate more discussion on the topic and encourage future mapping efforts.
A visual analytics approach for understanding biclustering results from microarray data
Directory of Open Access Journals (Sweden)
Quintales Luis
2008-05-01
Full Text Available Abstract Background Microarray analysis is an important area of bioinformatics. In the last few years, biclustering has become one of the most popular methods for classifying data from microarrays. Although biclustering can be used in any kind of classification problem, nowadays it is mostly used for microarray data classification. A large number of biclustering algorithms have been developed over the years, however little effort has been devoted to the representation of the results. Results We present an interactive framework that helps to infer differences or similarities between biclustering results, to unravel trends and to highlight robust groupings of genes and conditions. These linked representations of biclusters can complement biological analysis and reduce the time spent by specialists on interpreting the results. Within the framework, besides other standard representations, a visualization technique is presented which is based on a force-directed graph where biclusters are represented as flexible overlapped groups of genes and conditions. This microarray analysis framework (BicOverlapper, is available at http://vis.usal.es/bicoverlapper Conclusion The main visualization technique, tested with different biclustering results on a real dataset, allows researchers to extract interesting features of the biclustering results, especially the highlighting of overlapping zones that usually represent robust groups of genes and/or conditions. The visual analytics methodology will permit biology experts to study biclustering results without inspecting an overwhelming number of biclusters individually.
A Soft OR Approach to Fostering Systems Thinking: SODA Maps plus Joint Analytical Process
Wang, Shouhong; Wang, Hai
2016-01-01
Higher order thinking skills are important for managers. Systems thinking is an important type of higher order thinking in business education. This article investigates a soft Operations Research approach to teaching and learning systems thinking. It outlines the integrative use of Strategic Options Development and Analysis maps for visualizing…
Analytical approaches to food-based dietary guidelines in the European setting
Hulshof, K.F.A.M.; Valsta, L.M.; Welten, D.C.; Löwik, M.R.H.
2001-01-01
Objective: To show the effects of statistical approaches of data analysis to be used in the development of Food-Based Dietary Guidelines (FBDG). Setting: Databases from dietary surveys in 6 European countries. Results: Quantile analysis based on iron intake among adult women resulted in differences
Linear operators and linear systems an analytical approach to control theory
Partington, Jonathan R
2004-01-01
This book presents an introduction to the common ground between operator theory and linear systems theory. Suitable for students of functional analysis, this book also acts as an introduction to a mathematical approach to systems and control for graduate students in departments of applied mathematics or engineering.
Analytical Review of Universal Grammar (UG) Approach on Second Language Acquisition (SLA)
Irwandy
2015-01-01
The aim of this paper is to explore the analysis of Universal Grammar (UG) approach on Second Language Acquisition (SLA). This paper is significant as the sources for teacher or researcher of the second language since this elaboration is deeply focusing on the use of UG on SLA. The method used in this academic writing is inductive method of…
Microeconomics of the Productivity, Price Indicators and Farm Incomes. Analytical Approach
Directory of Open Access Journals (Sweden)
Włodzimierz Rembisz
2011-07-01
Full Text Available The paper develops a farm producer behavior type model to analyze the impact of a input productivity and price change on farm incomes. The theoretical analysis shows the consequences of the balance between the increase of production factor prices and their productivity improvement in the condition of stable procurement price for the farm producers income. The cost effect of the production factors price increment and its neutralization by productivity (TFP-type growth is examined as well as some aspects of the inputs shares (returns and costs in the produce value. The article argues that labor input productivity as an endogenous factor, is an essential for farm incomes growth assuming the specified type of the farm producer utility function (its equations and variables as well as no the compensative procurement price change conditions. Some empirical evidence is attached however more work in that respect is foreseen.
Sharafi, Mojtaba Meidan; Nikravesh, Majid Yadavar; Safarpour, Pedram
2017-09-01
In this paper, bending, longitudinal and torsional stiffness of an eccentric circumferential crack is investigated with taking into account contact condition on the crack surfaces based on fracture mechanics. Although several researches have analyzed stress intensity factors of symmetric circumferential crack, the stiffness of an asymmetric circumferential crack in different directions (along and perpendicular to eccentricity) regarding contact condition has not been studied by an analytical method until now. In this paper we aim to describe behavior of eccentric circumferential crack under axial loading and establish a relation between axial force and the resulting displacement vector. The twisting angle of asymmetric circumferential crack due to torsional loading is also calculated and compared to twisting angle of a symmetric crack. In order to simulate the local bending stiffness in the contact condition, nonlinear governing equations of bending stiffness associated to cracked beam section is developed by dividing it to strip elements and utilizing stiffness equations related to noncontact condition. It is validated by 3D finite element (FE) nonlinear model. Results show a significant compatibility between presented analytical and 3D FE methods. Moreover results of simulations show that without taking into account contact condition, axial, torsional and bending stiffness of symmetric and asymmetric circumferential crack are equal and radius of un-cracked area is the only influential factor.
Thevis, Mario; Schänzer, Wilhelm
2014-12-01
The number and diversity of potentially performance-enhancing substances is continuously growing, fueled by new pharmaceutical developments but also by the inventiveness and, at the same time, unscrupulousness of black-market (designer) drug producers and providers. In terms of sports drug testing, this situation necessitates reactive as well as proactive research and expansion of the analytical armamentarium to ensure timely, adequate, and comprehensive doping controls. This review summarizes literature published over the past 5 years on new drug entities, discontinued therapeutics, and 'tailored' compounds classified as doping agents according to the regulations of the World Anti-Doping Agency, with particular attention to analytical strategies enabling their detection in human blood or urine. Among these compounds, low- and high-molecular mass substances of peptidic (e.g. modified insulin-like growth factor-1, TB-500, hematide/peginesatide, growth hormone releasing peptides, AOD-9604, etc.) and non-peptidic (selective androgen receptor modulators, hypoxia-inducible factor stabilizers, siRNA, S-107 and ARM036/aladorian, etc.) as well as inorganic (cobalt) nature are considered and discussed in terms of specific requirements originating from physicochemical properties, concentration levels, metabolism, and their amenability for chromatographic-mass spectrometric or alternative detection methods.
DEFF Research Database (Denmark)
Radchenko, T. M.; Shylau, A. A.; Zozoulenko, I. V.
2013-01-01
Charge carrier transport in single-layer graphene with one-dimensional charged defects is studied theoretically. Extended charged defects, considered an important factor for mobility degradation in chemically vapor-deposited graphene, are described by a self-consistent Thomas-Fermi potential. A n...
W. Ketter (Wolfgang); M. Peters (Markus); J. Collins (John); A. Gupta (Alok)
2015-01-01
textabstractWicked problems like sustainable energy and financial market stability are societal challenges that arise from complex socio-technical systems in which numerous social, economic, political, and technical factors interact. Understanding and mitigating them requires research methods that s
A convective-advective balance approach for solving some nonlinear evolution equations analytically
Energy Technology Data Exchange (ETDEWEB)
Abdel Hamid, B. [United Arab Emirates Univ. (United Arab Emirates). Dept. of Mathematics and Computer Science
1999-09-01
A symbolic computation-based approach of balancing the convective and advective effects in a nonlinear evolution equation leads to a transformation that maps the nonlinear equation onto either a linear one or to a system of linear and homogeneous equations. The method is demonstrated by mapping Burgers' equation and nonlinear heat equation onto the linear heat equation. It is shown that the transformation obtained by balancing the convective-advective effects are reducible to those obtained by the Cole and Hopf through Backlund transformation. The method is also used to transform the modified KdV equation into a system of linear and homogeneous functions in the partial derivatives which leads to an exact solution. Computations in the presented approach are carried out in a straightforward way.
Chambers, Alan H; Pillet, Jeremy; Plotto, Anne; Bai, Jinhe; Whitaker, Vance M; Folta, Kevin M
2014-04-17
There is interest in improving the flavor of commercial strawberry (Fragaria × ananassa) varieties. Fruit flavor is shaped by combinations of sugars, acids and volatile compounds. Many efforts seek to use genomics-based strategies to identify genes controlling flavor, and then designing durable molecular markers to follow these genes in breeding populations. In this report, fruit from two cultivars, varying for presence-absence of volatile compounds, along with segregating progeny, were analyzed using GC/MS and RNAseq. Expression data were bulked in silico according to presence/absence of a given volatile compound, in this case γ-decalactone, a compound conferring a peach flavor note to fruits. Computationally sorting reads in segregating progeny based on γ-decalactone presence eliminated transcripts not directly relevant to the volatile, revealing transcripts possibly imparting quantitative contributions. One candidate encodes an omega-6 fatty acid desaturase, an enzyme known to participate in lactone production in fungi, noted here as FaFAD1. This candidate was induced by ripening, was detected in certain harvests, and correlated with γ-decalactone presence. The FaFAD1 gene is present in every genotype where γ-decalactone has been detected, and it was invariably missing in non-producers. A functional, PCR-based molecular marker was developed that cosegregates with the phenotype in F1 and BC1 populations, as well as in many other cultivars and wild Fragaria accessions. Genetic, genomic and analytical chemistry techniques were combined to identify FaFAD1, a gene likely controlling a key flavor volatile in strawberry. The same data may now be re-sorted based on presence/absence of any other volatile to identify other flavor-affecting candidates, leading to rapid generation of gene-specific markers.
Procida, Giuseppe; Cichelli, Angelo; Lagazio, Corrado; Conte, Lanfranco S
2016-01-15
The volatile fraction of virgin olive oil is characterised by low molecular weight compounds that vaporise at room temperature. In order to obtain an aroma profile similar to natural olfactory perception, the composition of the volatile compounds was determined by applying dynamic headspace gas chromatography, performed at room temperature, with a cryogenic trap directly connected to a gas chromatograph-mass spectrometer system. Samples were also evaluated according to European Union and International Olive Council official methods for sensory evaluation. In this paper, the composition of the volatile fraction of 25 extra virgin olive oils from different regions of Italy was analysed and some preliminary considerations on relationships between chemical composition of volatile fraction and sensory characteristics are reported. Forty-two compounds were identified by means of the particular analytical technique used. All the analysed samples, classified as extra virgin by the panel test, never present peaks whose magnitude is important enough in defected oils. The study was focused on the evaluation of volatile compounds responsible for the positive impact on olive odour properties ('green-fruity' and 'sweet') and olfactory perception. Chemometric evaluation of data, obtained through headspace analysis and the panel test evaluation, showed a correlation between chemical compounds and sensory properties. On the basis of the results, the positive attributes of virgin olive oil are divided into two separated groups: sweet types or green types. Sixteen volatile compounds with known positive impact on odour properties were extracted and identified. In particular, eight compounds seem correlated with sweet properties whereas the green sensation appears to be correlated with eight other different substances. The content of the compounds at six carbon atoms proves to be very important in defining positive attributes of extra virgin olive oils and sensory evaluation. © 2015
Remote Internet access to advanced analytical facilities: a new approach with Web-based services.
Sherry, N; Qin, J; Fuller, M Suominen; Xie, Y; Mola, O; Bauer, M; McIntyre, N S; Maxwell, D; Liu, D; Matias, E; Armstrong, C
2012-09-04
Over the past decade, the increasing availability of the World Wide Web has held out the possibility that the efficiency of scientific measurements could be enhanced in cases where experiments were being conducted at distant facilities. Examples of early successes have included X-ray diffraction (XRD) experimental measurements of protein crystal structures at synchrotrons and access to scanning electron microscopy (SEM) and NMR facilities by users from institutions that do not possess such advanced capabilities. Experimental control, visual contact, and receipt of results has used some form of X forwarding and/or VNC (virtual network computing) software that transfers the screen image of a server at the experimental site to that of the users' home site. A more recent development is a web services platform called Science Studio that provides teams of scientists with secure links to experiments at one or more advanced research facilities. The software provides a widely distributed team with a set of controls and screens to operate, observe, and record essential parts of the experiment. As well, Science Studio provides high speed network access to computing resources to process the large data sets that are often involved in complex experiments. The simple web browser and the rapid transfer of experimental data to a processing site allow efficient use of the facility and assist decision making during the acquisition of the experimental results. The software provides users with a comprehensive overview and record of all parts of the experimental process. A prototype network is described involving X-ray beamlines at two different synchrotrons and an SEM facility. An online parallel processing facility has been developed that analyzes the data in near-real time using stream processing. Science Studio and can be expanded to include many other analytical applications, providing teams of users with rapid access to processed results along with the means for detailed
Ramli, Razamin; Cheng, Kok-Min
2014-07-01
One of the important areas of concern in order to obtain a competitive level of productivity in a manufacturing system is the layout design and material transportation system (conveyor system). However, changes in customers' requirements have triggered the need to design other alternatives of the manufacturing layout for existing production floor. Hence, this paper discusses effective alternatives of the process layout specifically, the conveyor system layout. Subsequently, two alternative designs for the conveyor system were proposed with the aims to increase the production output and minimize space allocation. The first proposed layout design includes the installation of conveyor oven in the particular manufacturing room based on priority, and the second one is the one without the conveyor oven in the layout. Simulation technique was employed to design the new facility layout. Eventually, simulation experiments were conducted to understand the performance of each conveyor layout design based on operational characteristics, which include predicting the output of layouts. Utilizing the Analytic Hierarchy Process (AHP), the newly and improved layout designs were assessed before the final selection was done. As a comparison, the existing conveyor system layout was included in the assessment process. Relevant criteria involved in this layout design problem were identified as (i) usage of space of each design, (ii) operator's utilization rates, (iii) return of investment (ROI) of the layout, and (iv) output of the layout. In the final stage of AHP analysis, the overall priority of each alternative layout was obtained and thus, a selection for final use by the management was made based on the highest priority value. This efficient planning and designing of facility layout in a particular manufacturing setting is able to minimize material handling cost, minimize overall production time, minimize investment in equipment, and optimize utilization of space.
A Visual Analytics Approach for Understanding Reasons behind Snowballing and Comeback in MOBA Games.
Li, Quan; Xu, Peng; Chan, Yeuk Yin; Wang, Yun; Wang, Zhipeng; Qu, Huamin; Ma, Xiaojuan
2017-01-01
To design a successful Multiplayer Online Battle Arena (MOBA) game, the ratio of snowballing and comeback occurrences to all matches played must be maintained at a certain level to ensure its fairness and engagement. Although it is easy to identify these two types of occurrences, game developers often find it difficult to determine their causes and triggers with so many game design choices and game parameters involved. In addition, the huge amounts of MOBA game data are often heterogeneous, multi-dimensional and highly dynamic in terms of space and time, which poses special challenges for analysts. In this paper, we present a visual analytics system to help game designers find key events and game parameters resulting in snowballing or comeback occurrences in MOBA game data. We follow a user-centered design process developing the system with game analysts and testing with real data of a trial version MOBA game from NetEase Inc. We apply novel visualization techniques in conjunction with well-established ones to depict the evolution of players' positions, status and the occurrences of events. Our system can reveal players' strategies and performance throughout a single match and suggest patterns, e.g., specific player' actions and game events, that have led to the final occurrences. We further demonstrate a workflow of leveraging human analyzed patterns to improve the scalability and generality of match data analysis. Finally, we validate the usability of our system by proving the identified patterns are representative in snowballing or comeback matches in a one-month-long MOBA tournament dataset.