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Sample records for barbara cluster comparison

  1. Barbara Cooney.

    Science.gov (United States)

    Horne, Jackie C.

    2000-01-01

    Profiles the life/work of the award winning picture-book author-illustrator Barbara Cooney. Includes her early development as an artist; early attempts at the picture-book form; experimentation with different media: watercolor, pen/ink with wash, charcoal, acrylics, pastels, and collage; later work that draws upon folk-art traditions; her love of…

  2. Comparison of fishes taken by a sportfishing party vessel around oil platforms and adjacent natural reefs near Santa Barbara, California

    International Nuclear Information System (INIS)

    Love, M.S.; Westphal, W.

    1990-01-01

    Since 1958, 29 oil platforms have been sited in the southern California Bight of which 28 still remain in place. However, little is known of the fish populations surrounding these structures, particularly those sited in water deeper than 30 m. In the course of research on the Santa Barbara, California, party vessel sport fishery, it was noted that the platforms off Santa Barbara supported considerable sportfishing activity. Those platforms, located to the southeast of Santa Barbara in depths of 48-62 m, were particularly important and were fished intensively for various rockfishes (genus Sebastes). When fishing a platform, the vessel pulled up to within 5-10 m of a platform and drifts along one side, with the vessel operator using intermittent power to keep it near the structure. Most of the desirable species, particularly rockfishes, remained close to the platforms, rarely venturing more than perhaps 20 m from the structure. The party vessels also spent considerable time fishing over nearby natural reefs. In this survey, it was noted that there appeared to be differences in species catch composition and fish size between oil platforms and these natural reefs. Increased offshore oil drilling off California has raised interest in the role platforms play in marine systems. Questions have been raised regarding what fish live around platforms, how these structures influence populations over surrounding reefs, and whether the platforms act as fish enhancers (promoting recruitment) or only as aggregators. These questions are particularly relevant when the platforms are to be decommissioned and the possibility of allowing them to remain as artificial reefs is raised. This paper describes the results of the study on the fish populations around oil platforms and nearby natural reefs off Santa Barbara

  3. Barbara Stanwyck's Anklet

    Directory of Open Access Journals (Sweden)

    Paula Rabinowitz

    2001-01-01

    Full Text Available Los objetos tienen siempre un poder ineludible como significantes. El género fílmico negro está también dotado de una identidad propia a partir de un conjunto de imágenes, argumentos, estilos visuales y objetos por ejemplo, encendedores, persianas y, como elemento central de este trabajo, zapatos. El zapato como emblema de la muerte e icono sexual deviene fundamental en la puesta en escena del género negro. Cuando la “femme fatale” Phyllis Dietrichson (Barbara Stanwyck, por ejemplo, desciende la escalera para encontrarse con el corredor de seguros Walter Neff (Fred Mc Murray en la película de Billy Wilder Persuasión (1944, la cámara enfoca sus piernas blancas y relucientes hasta alcanzar sus pies y sus tobillos, con el fin de evocar el poder fetichista del pie de una mujer a la hora de controlar a un hombre.

  4. A COMPARISON OF TWO FUZZY CLUSTERING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Samarjit Das

    2013-10-01

    Full Text Available - In fuzzy clustering, unlike hard clustering, depending on the membership value, a single object may belong exactly to one cluster or partially to more than one cluster. Out of a number of fuzzy clustering techniques Bezdek’s Fuzzy C-Means and GustafsonKessel clustering techniques are well known where Euclidian distance and Mahalanobis distance are used respectively as a measure of similarity. We have applied these two fuzzy clustering techniques on a dataset of individual differences consisting of fifty feature vectors of dimension (feature three. Based on some validity measures we have tried to see the performances of these two clustering techniques from three different aspects- first, by initializing the membership values of the feature vectors considering the values of the three features separately one at a time, secondly, by changing the number of the predefined clusters and thirdly, by changing the size of the dataset.

  5. Interview: William and Barbara Christopher.

    Science.gov (United States)

    Teaching Exceptional Children, 1986

    1986-01-01

    Asserting that the biggest mistake educators can make is to set themselves up as experts vis-a-vis parents as amateurs, Barbara and William Christopher emphasize the importance of continued education for the autistic individual and relate their experiences with the educational community as they sought help for their autistic son. (JC)

  6. Cluster policy in Europe and Asia: A comparison using selected cluster policy characteristics

    Directory of Open Access Journals (Sweden)

    Martina Sopoligová

    2017-10-01

    Full Text Available Currently, cluster concept is one of the most important tools for governments to enhance competitiveness and innovations through sectoral specialization and cooperation. The paper focuses on applications of the cluster policy in the distinct territorial context of Europe and Asia so that to perform a comparison between different approaches to the cluster concept application in real practice. The paper introduces a comparative study of the cluster policy concepts based on the characteristics defined by the authors, such as scope, approach, targeting, autonomy, institutional coordination, policy instruments and evaluation system studied for the selected European and Asian countries such as Denmark, France, Germany, China, Japan, and South Korea. The research draws upon processing the secondary data obtained through content analysis of the related literature, government documents and strategies, and also cluster funding programmes. The findings demonstrate the diversity of cluster policies implemented in the context of European and Asian conditions at the current stage of their development.

  7. Santa Barbara Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, Angela; Hansen, Sherman; Watkins, Ashley

    2013-11-30

    This report serves as the Final Report for Santa Barbara County’s Energy Efficiency and Conservation Block Grant (EECBG) BetterBuildings Neighborhood Program (BBNP) award from the U.S. Department of Energy (DOE). This report explains how DOE BBNP funding was invested to develop robust program infrastructure designed to help property owners complete energy improvements, thereby generating substantial outcomes for the local environment and economy. It provides an overview of program development and design within the grant period, program accomplishments and challenges to date, and a plan for the future sustainability of emPower, the County’s innovative clean energy and building efficiency program. During the grant period, Santa Barbara County’s emPower program primarily targeted 32,000 owner occupied, single family, detached residential homes over 25 years old within the County. In order to help these homeowners and their contractors overcome market barriers to completing residential energy improvements, the program developed and promoted six voluntary, market-based service areas: 1) low cost residential financing (loan loss reserve with two local credit unions), 2) residential rebates, 3) local customer service, 4) expert energy advising, 5) workforce development and training, and 6) marketing, education and outreach. The main goals of the program were to lower building energy use, create jobs and develop a lasting regional building performance market. These services have generated important early outcomes and lessons after the program’s first two years in service. The DOE BBNP funding was extended through October 2014 to enable Santa Barbara County to generate continued outcomes. In fact, funding related to residential financing remains wholly available for the foreseeable future to continue offering Home Upgrade Loans to approximately 1,300 homeowners. The County’s investment of DOE BBNP funding was used to build a lasting, effective, and innovative

  8. Comparison of Intra-cluster and M87 Halo Orphan Globular Clusters in the Virgo Cluster

    Science.gov (United States)

    Louie, Tiffany Kaye; Tuan, Jin Zong; Martellini, Adhara; Guhathakurta, Puragra; Toloba, Elisa; Peng, Eric; Longobardi, Alessia; Lim, Sungsoon

    2018-01-01

    We present a study of “orphan” globular clusters (GCs) — GCs with no identifiable nearby host galaxy — discovered in NGVS, a 104 deg2 CFHT/MegaCam imaging survey. At the distance of the Virgo cluster, GCs are bright enough to make good spectroscopic targets and many are barely resolved in good ground-based seeing. Our orphan GC sample is derived from a subset of NGVS-selected GC candidates that were followed up with Keck/DEIMOS spectroscopy. While our primary spectroscopic targets were candidate GC satellites of Virgo dwarf elliptical and ultra-diffuse galaxies, many objects turned out to be non-satellites based on a radial velocity mismatch with the Virgo galaxy they are projected close to. Using a combination of spectral characteristics (e.g., absorption vs. emission), Gaussian mixture modeling of radial velocity and positions, and extreme deconvolution analysis of ugrizk photometry and image morphology, these non-satellites were classified into: (1) intra-cluster GCs (ICGCs) in the Virgo cluster, (2) GCs in the outer halo of M87, (3) foreground Milky Way stars, and (4) background galaxies. The statistical distinction between ICGCs and M87 halo GCs is based on velocity distributions (mean of 1100 vs. 1300 km/s and dispersions of 700 vs. 400 km/s, respectively) and radial distribution (diffuse vs. centrally concentrated, respectively). We used coaddition to increase the spectral SNR for the two classes of orphan GCs and measured the equivalent widths (EWs) of the Mg b and H-beta absorption lines. These EWs were compared to single stellar population models to obtain mean age and metallicity estimates. The ICGCs and M87 halo GCs have = –0.6+/–0.3 and –0.4+/–0.3 dex, respectively, and mean ages of >~ 5 and >~ 10 Gyr, respectively. This suggests the M87 halo GCs formed in relatively high-mass galaxies that avoided being tidally disrupted by M87 until they were close to the cluster center, while IGCCs formed in relatively low-mass galaxies that were

  9. Barbara Trenholm | IDRC - International Development Research ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    She is a past board member of Atomic Energy Canada Limited (AECL) and CPA Canada (formerly the Canadian Institute of Chartered Accountants). Barbara also served as past president of CPA New Brunswick (formerly the New Brunswick Institute of Chartered Accountants), and past acting dean of the Faculty of Business ...

  10. Applications of cluster analysis to the creation of perfectionism profiles: a comparison of two clustering approaches.

    Science.gov (United States)

    Bolin, Jocelyn H; Edwards, Julianne M; Finch, W Holmes; Cassady, Jerrell C

    2014-01-01

    Although traditional clustering methods (e.g., K-means) have been shown to be useful in the social sciences it is often difficult for such methods to handle situations where clusters in the population overlap or are ambiguous. Fuzzy clustering, a method already recognized in many disciplines, provides a more flexible alternative to these traditional clustering methods. Fuzzy clustering differs from other traditional clustering methods in that it allows for a case to belong to multiple clusters simultaneously. Unfortunately, fuzzy clustering techniques remain relatively unused in the social and behavioral sciences. The purpose of this paper is to introduce fuzzy clustering to these audiences who are currently relatively unfamiliar with the technique. In order to demonstrate the advantages associated with this method, cluster solutions of a common perfectionism measure were created using both fuzzy clustering and K-means clustering, and the results compared. Results of these analyses reveal that different cluster solutions are found by the two methods, and the similarity between the different clustering solutions depends on the amount of cluster overlap allowed for in fuzzy clustering.

  11. Applications of Cluster Analysis to the Creation of Perfectionism Profiles: A Comparison of two Clustering Approaches

    Directory of Open Access Journals (Sweden)

    Jocelyn H Bolin

    2014-04-01

    Full Text Available Although traditional clustering methods (e.g., K-means have been shown to be useful in the social sciences it is often difficult for such methods to handle situations where clusters in the population overlap or are ambiguous. Fuzzy clustering, a method already recognized in many disciplines, provides a more flexible alternative to these traditional clustering methods. Fuzzy clustering differs from other traditional clustering methods in that it allows for a case to belong to multiple clusters simultaneously. Unfortunately, fuzzy clustering techniques remain relatively unused in the social and behavioral sciences. The purpose of this paper is to introduce fuzzy clustering to these audiences who are currently relatively unfamiliar with the technique. In order to demonstrate the advantages associated with this method, cluster solutions of a common perfectionism measure were created using both fuzzy clustering and K-means clustering, and the results compared. Results of these analyses reveal that different cluster solutions are found by the two methods, and the similarity between the different clustering solutions depends on the amount of cluster overlap allowed for in fuzzy clustering.

  12. MOCCA code for star cluster simulation: comparison with optical observations using COCOA

    Science.gov (United States)

    Askar, Abbas; Giersz, Mirek; Pych, Wojciech; Olech, Arkadiusz; Hypki, Arkadiusz

    2016-02-01

    We introduce and present preliminary results from COCOA (Cluster simulatiOn Comparison with ObservAtions) code for a star cluster after 12 Gyr of evolution simulated using the MOCCA code. The COCOA code is being developed to quickly compare results of numerical simulations of star clusters with observational data. We use COCOA to obtain parameters of the projected cluster model. For comparison, a FITS file of the projected cluster was provided to observers so that they could use their observational methods and techniques to obtain cluster parameters. The results show that the similarity of cluster parameters obtained through numerical simulations and observations depends significantly on the quality of observational data and photometric accuracy.

  13. Preliminary geologic map of the Santa Barbara coastal plain area, Santa Barbara County, California

    Science.gov (United States)

    Minor, Scott A.; Kellogg, Karl S.; Stanley, Richard G.; Stone, Paul; Powell, Charles L.; Gurrola, Larry D.; Selting, Amy J.; Brandt, Theodore R.

    2002-01-01

    This report presents a new geologic digital map of the Santa Barbara coastal plain area at a compilation scale of 1:24,000 (one inch on the map = 2,000 feet on the ground) and with a horizontal positional accuracy of at least 20 m. This preliminary map depicts the distribution of bedrock units and surficial deposits and associated deformation underlying and adjacent to the coastal plain within the contiguous Santa Barbara and Goleta 7.5' quadrangles. A planned second version will extend the mapping westward into the adjoining Dos Pueblos Canyon quadrangle and eastward into the Carpinteria quadrangle. The mapping presented here results from the collaborative efforts of geologists with the U.S. Geological Survey Southern California Areal Mapping Project (SCAMP) (Minor, Kellogg, Stanley, Stone, and Powell) and the tectonic geomorphology research group at the University of California at Santa Barbara (Gurrola and Selting). C.L. Powell, II, performed all new fossil identifications and interpretations reported herein. T.R. Brandt designed and edited the GIS database,performed GIS database integration and created the digital cartography for the map layout. The Santa Barbara coastal plain is located in the western Transverse Ranges physiographic province along a west-trending segment of the southern California coastline about 100 km (62 mi) northwest of Los Angeles. The coastal plain region, which extends from the Santa Ynez Mountains on the north to the Santa Barbara Channel on the south, is underlain by numerous active and potentially active folds and partly buried thrust faults of the Santa Barbara fold and fault belt. Strong earthquakes that occurred in the region in 1925 (6.8 magnitude) and 1978 (5.1 magnitude) are evidence that such structures pose a significant earthquake hazard to the approximately 200,000 people living within the major coastal population centers of Santa Barbara and Goleta. Also, young landslide deposits along the steep lower flank of the Santa

  14. Comparison Of Clustering Techniques And A Univariate Technique ...

    African Journals Online (AJOL)

    In further analysis of clustering technique and with the application of either complete linkage or further neighbour linkage methods, there was a positive perfect correlation on the memberships of the groups. Therefore, any of these two techniques could be used to group locations. The only difference is that clustering ...

  15. A comparison of ACO and Abell catalogs of clusters

    International Nuclear Information System (INIS)

    Scaramella, R.; Zamorani, G.; Vettolani, G.; Chincarini, G.

    1991-01-01

    The results of a statistical analysis of the ACO and Abell catalog of clusters of galaxies are presented. For both catalogs, new estimates of distances, surface, and radial densities are derived. In particular, for the ACO catalog it is found that the derived radial-density distribution (including R = 0 clusters) is consistent with a uniform density of clusters up to at least 350/h Mpc. Moreover, within this distance the ACO data do not show any significant deficiency of R = 0 clusters. In both catalogs the effects of large angular gradients and derive maximum-likelihood estimates for the interesting parameters (i.e., galactic latitude and zenithal dependencies) are also studied. The ACO catalog appears to be more complete, with a larger volume density of clusters than the Abell catalog. 30 refs

  16. Determination of hydrogen cluster velocities and comparison with numerical calculations

    International Nuclear Information System (INIS)

    Täschner, A.; Köhler, E.; Ortjohann, H.-W.; Khoukaz, A.

    2013-01-01

    The use of powerful hydrogen cluster jet targets in storage ring experiments led to the need of precise data on the mean cluster velocity as function of the stagnation temperature and pressure for the determination of the volume density of the target beams. For this purpose a large data set of hydrogen cluster velocity distributions and mean velocities was measured at a high density hydrogen cluster jet target using a trumpet shaped nozzle. The measurements have been performed at pressures above and below the critical pressure and for a broad range of temperatures relevant for target operation, e.g., at storage ring experiments. The used experimental method is described which allows for the velocity measurement of single clusters using a time-of-flight technique. Since this method is rather time-consuming and these measurements are typically interfering negatively with storage ring experiments, a method for a precise calculation of these mean velocities was needed. For this, the determined mean cluster velocities are compared with model calculations based on an isentropic one-dimensional van der Waals gas. Based on the obtained data and the presented numerical calculations, a new method has been developed which allows to predict the mean cluster velocities with an accuracy of about 5%. For this two cut-off parameters defining positions inside the nozzle are introduced, which can be determined for a given nozzle by only two velocity measurements

  17. Towards Urban High-technolgy Clusters: An International Comparison

    Directory of Open Access Journals (Sweden)

    Júlia Bosch

    2012-01-01

    Full Text Available This paper presents the results of a comparative study of 23 urban or regional high-technology clusters (media, ICT, energy, biotechnology all over the world, analyzing how they were created, how they are managed and how they operate, and the strategies followed to improve and excel in their fields of action. Special attention is given to issues related to descriptive aspects, R&D, performance of the clusters, location factors and incentives to attract companies. The empirical analysis applied to the identified clusters was done through a questionnaire sent to the representatives of the cluster’s management. When analyzing the data, the study has combined quantitative and qualitative methods, depending on the information to be processed. The data collection was done through a selection of indicators chosen in order to cover the different elements that cluster literature coincide in consider essential to develop a competitive economic cluster in urban regions. The main obstacle we find with the information available to carry out this study has been its heterogeneity and different quality of the data. 22@Barcelona appears to be in a good position to compete with other excelling clusters, but it still needs to improve in areas such as financial supply for R&D and start-ups and coordination between the different actors involved in urban economic development. Our research also contributes to the discussion on the role of public institutions in the cluster development policies. In the clusters studied here, especially in Barcelona, we have seen that a capable and resourceful public administration can determine the success of the cluster initiative.

  18. Mentors, Muses, and Mutuality: Honoring Barbara Snell Dohrenwend

    Science.gov (United States)

    Mulvey, Anne

    2012-01-01

    I describe feminist community psychology principles that have the potential to expand and enrich mentoring and that honor Barbara Snell Dohrenwend, a leader who contributed to the research, theory, and profession of community psychology. I reflect on the affect that Barbara Dohrenwend had on life and on the development of feminist community…

  19. Rannus mängitakse suvel Barbara lugu

    Index Scriptorium Estoniae

    2007-01-01

    Augustis on Rannus näitlejate ja näitejuhtide suvekool, mille tipphetk on ühine vabaõhuetendus "Barbara lugu", lavastajaks Jüri Lumiste. Artiklis ka lühidalt Barbara von Tiesenhuseni, kes oli Rannu lossi Tiesenhusenite 12 lapsest noorim, saatusest

  20. I shop, therefore I am: Barbara Kruger

    Directory of Open Access Journals (Sweden)

    Alejandra Val Cubero

    2012-06-01

    Full Text Available La artista Barbara Kruger formada en la Parson Design School de Nueva York, bebió de las corrientes feministas de los años setenta y ochenta, y sirviéndose de las técnicas publicitarias con el uso de sloganes directos, breves e impactantes en tonos rojos y negros, utilizó el lenguaje de los medios de comunicación para criticar, durante más de cuatro décadas, aspectos relativos a la sociedad de consumo y las relaciones de género. En la actualidad su obra ha sido fagocitada por el propio mercado artístico y es necesario abrir nuevos caminos que conozcan la lógica de la publicidad comercial y la subviertan.

  1. Sequence comparison on a cluster of workstations using the PVM system

    Energy Technology Data Exchange (ETDEWEB)

    Guan, X.; Mural, R.J.; Uberbacher, E.C.

    1995-02-01

    We have implemented a distributed sequence comparison algorithm on a cluster of workstations using the PVM paradigm. This implementation has achieved similar performance to the intel iPSC/860 Hypercube, a massively parallel computer. The distributed sequence comparison algorithm serves as a search tool for two Internet servers GRAIL and GENQUEST. This paper describes the implementation and the performance of the algorithm.

  2. A comparison of three clustering methods for finding subgroups in MRI, SMS or clinical data

    DEFF Research Database (Denmark)

    Kent, Peter; Jensen, Rikke K; Kongsted, Alice

    2014-01-01

    ). There is a scarcity of head-to-head comparisons that can inform the choice of which clustering method might be suitable for particular clinical datasets and research questions. Therefore, the aim of this study was to perform a head-to-head comparison of three commonly available methods (SPSS TwoStep CA, Latent Gold...

  3. A Differentiation Framework for Maritime Clusters: Comparisons across Europe

    Directory of Open Access Journals (Sweden)

    Paulo Neto

    2013-09-01

    Full Text Available The purpose of this paper is to point out some of the main characteristics and critical factors for success that can substantiate the proposal of a differentiation framework for maritime clusters. We conduct a benchmarking analysis intended to distinguish the most relevant aspects which can or should be observed in these types of clusters, applied to the following countries: Spain (Basque Country, Germany (Lander of Schleswig-Holstein, the Netherlands and Norway. The differentiation factors involve agglomeration economies and endogenous conditions derived from geographic proximity, essential for lowering transaction costs, strengthening the leverage of public/private cooperation through centres of maritime excellence, at the same time providing an adequate local environment that favours positive interactions between the different maritime industries and actors. The main results arising from this article are presented through a reconceptualisation of Porter’s Diamond framework for diagnosing the competitiveness of maritime clusters.

  4. Performance Comparison of Mainframe, Workstations, Clusters, and Desktop Computers

    Science.gov (United States)

    Farley, Douglas L.

    2005-01-01

    A performance evaluation of a variety of computers frequently found in a scientific or engineering research environment was conducted using a synthetic and application program benchmarks. From a performance perspective, emerging commodity processors have superior performance relative to legacy mainframe computers. In many cases, the PC clusters exhibited comparable performance with traditional mainframe hardware when 8-12 processors were used. The main advantage of the PC clusters was related to their cost. Regardless of whether the clusters were built from new computers or whether they were created from retired computers their performance to cost ratio was superior to the legacy mainframe computers. Finally, the typical annual maintenance cost of legacy mainframe computers is several times the cost of new equipment such as multiprocessor PC workstations. The savings from eliminating the annual maintenance fee on legacy hardware can result in a yearly increase in total computational capability for an organization.

  5. A Comparison of Methods for Player Clustering via Behavioral Telemetry

    DEFF Research Database (Denmark)

    Drachen, Anders; Thurau, C.; Sifa, R.

    2013-01-01

    patterns in the behavioral data, and developing profiles that are actionable to game developers. There are numerous methods for unsupervised clustering of user behavior, e.g. k-means/c-means, Nonnegative Matrix Factorization, or Principal Component Analysis. Although all yield behavior categorizations......, interpretation of the resulting categories in terms of actual play behavior can be difficult if not impossible. In this paper, a range of unsupervised techniques are applied together with Archetypal Analysis to develop behavioral clusters from playtime data of 70,014 World of Warcraft players, covering a five...

  6. Comparison of Cluster C personality disorders in couples with ...

    African Journals Online (AJOL)

    The main purpose of this study was to compare personality disorders in Cluster C with normal couples divorce. In this cross-sectional study.The study population consisted of men and women seeking divorce Urmia in 2010, which was referred to the offices of the two groups, men and women seeking divorce (33 males and ...

  7. A comparison of DNA barcode clustering methods applied to ...

    Indian Academy of Sciences (India)

    2012-10-15

    Oct 15, 2012 ... ABGD; biodiversity inventory; cluster analysis; cryptic species; cytochrome oxidase subunit I; DNA barcode of life; Fuzzy. Identification; GMYC; SAP .... set of phylogenetic trees is sampled using Bayesian Markov chain Monte Carlo ..... Critical factors for assembling a high volume of DNA barcodes. Philos.

  8. Comparison of CN-Band Strengths in Open Clusters

    Science.gov (United States)

    Hufnagel, B.

    1996-12-01

    Spectra at ~ 5 Angstroms resolution in the 3600--4600 Angstroms wavelength range have been obtained for 27 stars in the field of the old open cluster (M67) (NGC 2682) and for 14 stars of the younger Pleiades. Based on synthetic spectra (Briley 1996, private communication) of 23 M67 G-dwarf members and 14 Pleiads, the violet CN-band index is found to be adequate to detect a star-to-star spread in [N/H] for these G-dwarf spectra. No such [N/H] inhomogeneity was indicated. This is consistent with findings for unevolved stars in other open clusters, but is unlike the bimodality in CN-band strengths seen in globular cluster unevolved stars [Suntzeff 1989, in The Abundance Spread within Globular Clusters, (Paris, Obs. de Paris), 71: NGC 6752) and (Briley et al. 1994, AJ 108, 2183): 47 Tuc]. This homogeneity is also different than the significant spread in CN-band strengths of evolved stars in three other as old or older open clusters, Melotte 66, NGC 188, and NGC 6791 (Anthony-Twarog et al., 1994, AJ, 106, 486; McClure 1974, ApJ, 194, 355; and Hufnagel et al. 1995, AJ, 110, 693, respectively). This result is consistent with an evolutionary process that creates a dispersion in the CN-band strength distribution of evolved stars, but is only effective for stars turning off the main-sequence with a mass lower than some threshold mass, as suggested by other workers (e.g., Gilroy 1989, ApJ, 347, 835). The Pleiads were successfully modeled using enhanced [O/H] values (King 1994, PASP, 106, 423) and depleted [C/H] values, contrary to previous high-resolution results (e.g., Boesgaard & Friel 1990, ApJ, 351, 467).

  9. Comparison of wind mill cluster performance: A multicriteria approach

    Energy Technology Data Exchange (ETDEWEB)

    Rajakumar, D.G.; Nagesha, N. [Visvesvaraya Technological Univ., Karnataka (India)

    2012-07-01

    Energy is a crucial input for the economic and social development of any nation. Both renewable and non-renewable energy contribute in meeting the total requirement of the economy. As an affordable and clean energy source, wind energy is amongst the world's fastest growing renewable energy forms. Though there are several wind-mill clusters producing energy in different geographical locations, evaluating their performance is a complex task and not much of literature is available in this area. In this backdrop, an attempt is made in the current paper to estimate the performance of a wind-mill cluster through an index called Cluster Performance Index (CPI) adopting a multi-criteria approach. The proposed CPI comprises four criteria viz., Technical Performance Indicators (TePI), Economic Performance Indicators (EcPI), Environmental Performance Indicators (EnPI), and Sociological Performance Indicators (SoPI). Under each performance criterion a total of ten parameters are considered with five subjective and five objective oriented responses. The methodology is implemented by collecting empirical data from three wind-mill clusters located at Chitradurga, Davangere, and Gadag in the southern Indian State of Karnataka. Totally fifteen different stake holders are consulted through a set of structured researcher administered questionnaire to collect the relevant data in each wind farm. Stake holders involved engineers working in wind farms, wind farm developers, Government officials from energy department and a few selected residential people near the wind farms. The results of the study revealed that Chitradurga wind farm performed much better with a CPI of 45.267 as compared to Gadag (CPI of 28.362) and Davangere (CPI of 19.040) wind farms. (Author)

  10. 2017-2018 Travel Expense Reports for Barbara Lucille Trenholm ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    . Incidentals: $765.00. Other: $441.04. Total: $10,676.95. Comments: From her residence in Fredericton, NB. 2017-2018 Travel Expense Reports for Barbara. Lucille Trenholm, Governor, Chairperson of the. Finance and Audit Committee.

  11. Review of Barbara K. Seeber, Jane Austen and Animals

    Directory of Open Access Journals (Sweden)

    Lucinda Cole

    2015-03-01

    Full Text Available In this review of Barbara K. Seeber's Jane Austen and Animals (Ashgate, 2013 Lucinda Cole summarizes this foundational book and emphasizes the role of animal studies scholars in linking feminism and environmental issues.

  12. Santa Barbara, California Tsunami Forecast Grids for MOST Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Santa Barbara, California Forecast Model Grids provides bathymetric data strictly for tsunami inundation modeling with the Method of Splitting Tsunami (MOST)...

  13. A Comparison of Alternative Distributed Dynamic Cluster Formation Techniques for Industrial Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Mohammad Gholami

    2016-01-01

    Full Text Available In this paper, we investigate alternative distributed clustering techniques for wireless sensor node tracking in an industrial environment. The research builds on extant work on wireless sensor node clustering by reporting on: (1 the development of a novel distributed management approach for tracking mobile nodes in an industrial wireless sensor network; and (2 an objective comparison of alternative cluster management approaches for wireless sensor networks. To perform this comparison, we focus on two main clustering approaches proposed in the literature: pre-defined clusters and ad hoc clusters. These approaches are compared in the context of their reconfigurability: more specifically, we investigate the trade-off between the cost and the effectiveness of competing strategies aimed at adapting to changes in the sensing environment. To support this work, we introduce three new metrics: a cost/efficiency measure, a performance measure, and a resource consumption measure. The results of our experiments show that ad hoc clusters adapt more readily to changes in the sensing environment, but this higher level of adaptability is at the cost of overall efficiency.

  14. A Comparison of Alternative Distributed Dynamic Cluster Formation Techniques for Industrial Wireless Sensor Networks.

    Science.gov (United States)

    Gholami, Mohammad; Brennan, Robert W

    2016-01-06

    In this paper, we investigate alternative distributed clustering techniques for wireless sensor node tracking in an industrial environment. The research builds on extant work on wireless sensor node clustering by reporting on: (1) the development of a novel distributed management approach for tracking mobile nodes in an industrial wireless sensor network; and (2) an objective comparison of alternative cluster management approaches for wireless sensor networks. To perform this comparison, we focus on two main clustering approaches proposed in the literature: pre-defined clusters and ad hoc clusters. These approaches are compared in the context of their reconfigurability: more specifically, we investigate the trade-off between the cost and the effectiveness of competing strategies aimed at adapting to changes in the sensing environment. To support this work, we introduce three new metrics: a cost/efficiency measure, a performance measure, and a resource consumption measure. The results of our experiments show that ad hoc clusters adapt more readily to changes in the sensing environment, but this higher level of adaptability is at the cost of overall efficiency.

  15. Analysis and comparison of very large metagenomes with fast clustering and functional annotation

    Directory of Open Access Journals (Sweden)

    Li Weizhong

    2009-10-01

    Full Text Available Abstract Background The remarkable advance of metagenomics presents significant new challenges in data analysis. Metagenomic datasets (metagenomes are large collections of sequencing reads from anonymous species within particular environments. Computational analyses for very large metagenomes are extremely time-consuming, and there are often many novel sequences in these metagenomes that are not fully utilized. The number of available metagenomes is rapidly increasing, so fast and efficient metagenome comparison methods are in great demand. Results The new metagenomic data analysis method Rapid Analysis of Multiple Metagenomes with a Clustering and Annotation Pipeline (RAMMCAP was developed using an ultra-fast sequence clustering algorithm, fast protein family annotation tools, and a novel statistical metagenome comparison method that employs a unique graphic interface. RAMMCAP processes extremely large datasets with only moderate computational effort. It identifies raw read clusters and protein clusters that may include novel gene families, and compares metagenomes using clusters or functional annotations calculated by RAMMCAP. In this study, RAMMCAP was applied to the two largest available metagenomic collections, the "Global Ocean Sampling" and the "Metagenomic Profiling of Nine Biomes". Conclusion RAMMCAP is a very fast method that can cluster and annotate one million metagenomic reads in only hundreds of CPU hours. It is available from http://tools.camera.calit2.net/camera/rammcap/.

  16. clusters

    Indian Academy of Sciences (India)

    2017-09-27

    Sep 27, 2017 ... while CuCoNO, Co3NO, Cu3CoNO, Cu2Co3NO, Cu3Co3NO and Cu6CoNO clusters display stronger chemical stability. Magnetic and electronic properties are also discussed. The magnetic moment is affected by charge transfer and the spd hybridization. Keywords. CumConNO (m + n = 2–7) clusters; ...

  17. cluster

    Indian Academy of Sciences (India)

    has been investigated electrochemically in positive and negative microenvironments, both in solution and in film. Charge nature around the active centre ... in plants, bacteria and also in mammals. This cluster is also an important constituent of a ..... selection of non-cysteine amino acid in the active centre of Rieske proteins.

  18. Coresets vs clustering: comparison of methods for redundancy reduction in very large white matter fiber sets

    Science.gov (United States)

    Alexandroni, Guy; Zimmerman Moreno, Gali; Sochen, Nir; Greenspan, Hayit

    2016-03-01

    Recent advances in Diffusion Weighted Magnetic Resonance Imaging (DW-MRI) of white matter in conjunction with improved tractography produce impressive reconstructions of White Matter (WM) pathways. These pathways (fiber sets) often contain hundreds of thousands of fibers, or more. In order to make fiber based analysis more practical, the fiber set needs to be preprocessed to eliminate redundancies and to keep only essential representative fibers. In this paper we demonstrate and compare two distinctive frameworks for selecting this reduced set of fibers. The first framework entails pre-clustering the fibers using k-means, followed by Hierarchical Clustering and replacing each cluster with one representative. For the second clustering stage seven distance metrics were evaluated. The second framework is based on an efficient geometric approximation paradigm named coresets. Coresets present a new approach to optimization and have huge success especially in tasks requiring large computation time and/or memory. We propose a modified version of the coresets algorithm, Density Coreset. It is used for extracting the main fibers from dense datasets, leaving a small set that represents the main structures and connectivity of the brain. A novel approach, based on a 3D indicator structure, is used for comparing the frameworks. This comparison was applied to High Angular Resolution Diffusion Imaging (HARDI) scans of 4 healthy individuals. We show that among the clustering based methods, that cosine distance gives the best performance. In comparing the clustering schemes with coresets, Density Coreset method achieves the best performance.

  19. Clustering Scientific Publications Based on Citation Relations: A Systematic Comparison of Different Methods.

    Directory of Open Access Journals (Sweden)

    Lovro Šubelj

    Full Text Available Clustering methods are applied regularly in the bibliometric literature to identify research areas or scientific fields. These methods are for instance used to group publications into clusters based on their relations in a citation network. In the network science literature, many clustering methods, often referred to as graph partitioning or community detection techniques, have been developed. Focusing on the problem of clustering the publications in a citation network, we present a systematic comparison of the performance of a large number of these clustering methods. Using a number of different citation networks, some of them relatively small and others very large, we extensively study the statistical properties of the results provided by different methods. In addition, we also carry out an expert-based assessment of the results produced by different methods. The expert-based assessment focuses on publications in the field of scientometrics. Our findings seem to indicate that there is a trade-off between different properties that may be considered desirable for a good clustering of publications. Overall, map equation methods appear to perform best in our analysis, suggesting that these methods deserve more attention from the bibliometric community.

  20. Clustering Scientific Publications Based on Citation Relations: A Systematic Comparison of Different Methods.

    Science.gov (United States)

    Šubelj, Lovro; van Eck, Nees Jan; Waltman, Ludo

    2016-01-01

    Clustering methods are applied regularly in the bibliometric literature to identify research areas or scientific fields. These methods are for instance used to group publications into clusters based on their relations in a citation network. In the network science literature, many clustering methods, often referred to as graph partitioning or community detection techniques, have been developed. Focusing on the problem of clustering the publications in a citation network, we present a systematic comparison of the performance of a large number of these clustering methods. Using a number of different citation networks, some of them relatively small and others very large, we extensively study the statistical properties of the results provided by different methods. In addition, we also carry out an expert-based assessment of the results produced by different methods. The expert-based assessment focuses on publications in the field of scientometrics. Our findings seem to indicate that there is a trade-off between different properties that may be considered desirable for a good clustering of publications. Overall, map equation methods appear to perform best in our analysis, suggesting that these methods deserve more attention from the bibliometric community.

  1. Clustering Scientific Publications Based on Citation Relations: A Systematic Comparison of Different Methods

    Science.gov (United States)

    Šubelj, Lovro; van Eck, Nees Jan; Waltman, Ludo

    2016-01-01

    Clustering methods are applied regularly in the bibliometric literature to identify research areas or scientific fields. These methods are for instance used to group publications into clusters based on their relations in a citation network. In the network science literature, many clustering methods, often referred to as graph partitioning or community detection techniques, have been developed. Focusing on the problem of clustering the publications in a citation network, we present a systematic comparison of the performance of a large number of these clustering methods. Using a number of different citation networks, some of them relatively small and others very large, we extensively study the statistical properties of the results provided by different methods. In addition, we also carry out an expert-based assessment of the results produced by different methods. The expert-based assessment focuses on publications in the field of scientometrics. Our findings seem to indicate that there is a trade-off between different properties that may be considered desirable for a good clustering of publications. Overall, map equation methods appear to perform best in our analysis, suggesting that these methods deserve more attention from the bibliometric community. PMID:27124610

  2. Cluster A personality pathology in social anxiety disorder: a comparison with panic disorder.

    Science.gov (United States)

    O'Toole, Mia Skytte; Arendt, Mikkel; Fentz, Hanne Nørr; Hougaard, Esben; Rosenberg, Nicole K

    2014-10-01

    Social anxiety disorder (SAD) has been associated with cluster A personality disorder (PD) traits, mainly paranoid and schizoid traits. The aim of the study was to further investigate cluster A personality pathology in patients with SAD. Self-reported PD traits were investigated in a clinical sample of 161 participants with SAD and in a clinical comparison group of 145 participants with panic disorder with or without agoraphobia (PAD). A diagnosis of SAD was associated with more paranoid and schizotypal PD traits, and an association between depression and personality pathology could indicate a state-effect of depression on PD traits. Patients with SAD had more cluster A personality pathology than patients with PAD, with the most solid indication for paranoid personality pathology.

  3. Automatic video shot boundary detection using k-means clustering and improved adaptive dual threshold comparison

    Science.gov (United States)

    Sa, Qila; Wang, Zhihui

    2018-03-01

    At present, content-based video retrieval (CBVR) is the most mainstream video retrieval method, using the video features of its own to perform automatic identification and retrieval. This method involves a key technology, i.e. shot segmentation. In this paper, the method of automatic video shot boundary detection with K-means clustering and improved adaptive dual threshold comparison is proposed. First, extract the visual features of every frame and divide them into two categories using K-means clustering algorithm, namely, one with significant change and one with no significant change. Then, as to the classification results, utilize the improved adaptive dual threshold comparison method to determine the abrupt as well as gradual shot boundaries.Finally, achieve automatic video shot boundary detection system.

  4. La lecture de Merleau-Ponty par Renaud Barbaras

    Czech Academy of Sciences Publication Activity Database

    Pechar, Jiří

    2015-01-01

    Roč. 11, č. 2 (2015), s. 1-6 ISSN 1336-6556 Institutional support: RVO:67985955 Keywords : Merleau-Ponty * Husserl * phenomenology * linguistics of Ferdinand de Saussure Subject RIV: AA - Philosophy ; Religion http://www.ostium.sk/sk/la-lecture-de-merleau-ponty-par-renaud-barbaras/

  5. Barbara Thayer-Bacon on Knowers and the Known

    Science.gov (United States)

    McKenzie, Jim

    2002-01-01

    Barbara Thayer-Bacon (1999) objects to the minimum proficiency examinations that are mandated for school students in Ohio. Similar tests are required by, or are under consideration by, governments in many other parts of the world. Various writers have objected to one or other of these tests by arguing that they are crude, invalid, unreliable,…

  6. 2017-2018 Travel Expense Reports for Barbara Lucille Trenholm ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Airfare: $436.15. Other. Transportation: $98.00. Accommodation: $361.85. Meals and. Incidentals: $219.51. Other: $0.00. Total: $1,115.51. Comments: From her residence in Fredericton, NB. 2017-2018 Travel Expense Reports for. Barbara Lucille Trenholm, Governor,. Chairperson of the Finance and Audit. Committee.

  7. 2016-2017 Travel Expense Reports for Barbara Lucille Trenholm ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Beata Bialic

    2016-11-28 to 2016-11-30. Destination(s):. Ottawa. Airfare: $1,078.05. Other. Transportation: $135.00. Accommodation: $194.37. Meals and. Incidentals: $216.80. Other: $0.00. Total: $1,624.22. Comments: 2016-2017 Travel Expense Reports for Barbara. Lucille Trenholm, Governor, Chairperson of the. Finance and Audit ...

  8. 2016-2017 Travel Expense Reports for Barbara Lucille Trenholm ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Beata Bialic

    2016-06-20 to 2016-06-22. Destination(s):. Ottawa. Airfare: $603.34. Other. Transportation: $147.00. Accommodation: $393.40. Meals and. Incidentals: $154.83. Other: $0.00. Total: $1,298.57. Comments: 2016-2017 Travel Expense Reports for Barbara. Lucille Trenholm, Governor, Chairperson of the. Finance and Audit ...

  9. 2016-2017 Travel Expense Reports for Barbara Lucille Trenholm ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Beata Bialic

    Destination(s):. Peru/Colombia. Airfare: $3,662.66. Other. Transportation: $40.00. Accommodation: $1,941.64. Meals and. Incidentals: $608.10. Other: $93.22. Total: $6,345.62. Comments: 2016-2017 Travel Expense Reports for Barbara. Lucille Trenholm, Governor, Chairperson of the. Finance and Audit Committee.

  10. 2016-2017 Travel Expense Reports for Barbara Lucille Trenholm ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Beata Bialic

    2016-11-20 to 2016-11-23. Destination(s):. Ottawa. Airfare: $572.30. Other. Transportation: $130.00. Accommodation: $590.10. Meals and. Incidentals: $310.40. Other: $0.00. Total: $1,602.80. Comments: 2016-2017 Travel Expense Reports for Barbara. Lucille Trenholm, Governor, Chairperson of the. Finance and Audit ...

  11. 2016-2017 Travel Expense Reports for Barbara Lucille Trenholm ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    chantal taylor

    Finance and Audit Committee meeting. Date(s):. 2017-02-07 to 2017-02-09. Destination(s):. Ottawa. Airfare: $492.53. Other. Transportation: $70.00. Accommodation: $696.25. Meals and. Incidentals: $69.60. Other: $0.00. Total: $1,328.38. Comments: 2016-2017 Travel Expense Reports for Barbara. Lucille Trenholm ...

  12. 2017-2018 Travel Expense Reports for Barbara Lucille Trenholm ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Chantal Taylor

    Purpose: Board Meetings. Date(s):. 2017-11-19 to 2017-11-22. Destination(s):. Ottawa. Airfare: $630.16. Other. Transportation: $135.19. Accommodation: $638.43. Meals and. Incidentals: $208.98. Other: $0.00. Total: ... Reports for Barbara. Lucille Trenholm, Governor, Chairperson of the. Finance and Audit Committee.

  13. Barbara McClintock and the Discovery of Jumping Genes

    Indian Academy of Sciences (India)

    GENERAL I ARTICLE. Barbara McClintock and the Discovery of Jumping Genes. Vidyanand Nanjundiah works in the. Developmental Biology and Genetics Laboratory at the Indian Institute of. Science. After a Master's degree in physics he took up biology. He is interested in evolutionary biology and pattern formation during.

  14. Barbara Ryder to head Department of Computer Science

    OpenAIRE

    Daniilidi, Christina

    2008-01-01

    Barbara G. Ryder, professor of computer science at Rutgers, The State University of New Jersey, will become the computer science department head at Virginia Tech, starting in fall 2008. She is the first woman to serve as a department head in the history of the nationally ranked College of Engineering.

  15. A Conversation with AATE's Executive Director, Barbara Salisbury Wills.

    Science.gov (United States)

    Saldana, Johnny

    1997-01-01

    Presents an interview with the American Alliance for Theatre and Education's executive director Barbara Salisbury Wills. Discusses her interaction with the Goals 2000 Commission, development of the "National Standards for Arts Education," getting parents involved in theater education programs, working with state representatives, and…

  16. 77 FR 39638 - Safety Zone; Barbara Harder Wedding Fireworks, Lake Erie, Lake View, NY

    Science.gov (United States)

    2012-07-05

    ...-AA00 Safety Zone; Barbara Harder Wedding Fireworks, Lake Erie, Lake View, NY AGENCY: Coast Guard, DHS... during the Barbara Harder Wedding Fireworks. This temporary safety zone is necessary to protect... vessels during the Barbara Harder Wedding Fireworks. This zone will be effective and enforced from 9 p.m...

  17. Prevalence of foot disorders in captive Sardinian partridges (Alectoris barbara barbara Bonnaterre, 1790) as useful indicators of fitness to natural environment.

    Science.gov (United States)

    Cappai, M G; Abd El-Wahab, A; Arru, G; Muzzeddu, M; Pinna, W

    2018-04-01

    Foot health represents an issue in wild avifauna breeding practices. In particular, prevalence of digital ulceration (DU) and foot pad dermatitis (FPD) are valid indicators of welfare in wildlife conservation centres and may be interpreted as to fitness for bird's reintroduction into the wild. This study meant to test the effects of raising practices on foot pad health in captive Sardinian partridges (Alectoris barbara barbara Bonnaterre, 1790) reared for biodiversity conservation, to assess welfare and fitness to reintroduction into nature. A total of 22 couples were allotted into two experimental groups. In one group, 10 couples were housed in 10 cages for breeding partridges, consisting of two animals each, with metal wire flooring system, above trays where droppings were collected. The remaining 12 couples were housed in six aviaries, consisting of four animals each, on natural (earth and stones) ground. In both groups, partridges were fed identical diets. No significant differences of food pad scoring were found between birds housed in cages (2.3 ± 0.4) and those reared in aviaries on natural ground (2.5 ± 0.6). Moreover, scores of male foot pads for both groups (2.4 ± 0.6) had no significant differences in comparison with female foot pads, independently on housing (2.5 ± 0.4). Body mass (BM) was higher (+4.36%) than average BM reported for wild Sardinian partridges. Digital ulceration was found in the 20% of females, exclusively from the cage group. Body mass of females in cages with metal wire flooring appeared to be significantly (p < .001) and negatively correlated (r = -.528) with DU prevalence. These results suggest that housing conditions impacts differently on behaviour of females and males in one same couple, and this relates to foot health, in particular as to DU prevalence. © 2017 Blackwell Verlag GmbH.

  18. California State Waters Map Series: offshore of Santa Barbara, California

    Science.gov (United States)

    Johnson, Samuel Y.; Dartnell, Peter; Cochrane, Guy R.; Golden, Nadine E.; Phillips, Eleyne L.; Ritchie, Andrew C.; Greene, H. Gary; Krigsman, Lisa M.; Kvitek, Rikk G.; Dieter, Bryan E.; Endris, Charles A.; Seitz, Gordon G.; Sliter, Ray W.; Erdey, Mercedes D.; Gutierrez, Carlos I.; Wong, Florence L.; Yoklavich, Mary M.; Draut, Amy E.; Hart, Patrick E.; Conrad, James E.; Cochran, Susan A.; Johnson, Samuel Y.; Cochran, Susan A.

    2013-01-01

    In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and visualization of swath sonar data, acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow (to about 100 m) subsurface geology. The Offshore of Santa Barbara map area lies within the central Santa Barbara Channel region of the Southern California Bight. This geologically complex region forms a major biogeographic transition zone, separating the cold-temperate Oregonian province north of Point Conception from the warm-temperate California province to the south. The map area is in the southern part of the Western Transverse Ranges geologic province, which is north of the California Continental Borderland. Significant clockwise rotation—at least 90°—since the early Miocene has been proposed for the Western Transverse Ranges province, and geodetic studies indicate that the region is presently undergoing north-south shortening. Uplift rates (as much as 2.2 mm/yr) that are based on studies of onland marine terraces provide further evidence of significant shortening. The city of Santa Barbara, the main coastal population center in the map area, is part of a contiguous urban area that extends from Carpinteria to Goleta. This urban area was developed on the coalescing alluvial surfaces, uplifted marine terraces, and low hills that lie south of the east-west-trending Santa Ynez Mountains. Several beaches line the actively

  19. A novel Bayesian DNA motif comparison method for clustering and retrieval.

    Directory of Open Access Journals (Sweden)

    Naomi Habib

    2008-02-01

    Full Text Available Characterizing the DNA-binding specificities of transcription factors is a key problem in computational biology that has been addressed by multiple algorithms. These usually take as input sequences that are putatively bound by the same factor and output one or more DNA motifs. A common practice is to apply several such algorithms simultaneously to improve coverage at the price of redundancy. In interpreting such results, two tasks are crucial: clustering of redundant motifs, and attributing the motifs to transcription factors by retrieval of similar motifs from previously characterized motif libraries. Both tasks inherently involve motif comparison. Here we present a novel method for comparing and merging motifs, based on Bayesian probabilistic principles. This method takes into account both the similarity in positional nucleotide distributions of the two motifs and their dissimilarity to the background distribution. We demonstrate the use of the new comparison method as a basis for motif clustering and retrieval procedures, and compare it to several commonly used alternatives. Our results show that the new method outperforms other available methods in accuracy and sensitivity. We incorporated the resulting motif clustering and retrieval procedures in a large-scale automated pipeline for analyzing DNA motifs. This pipeline integrates the results of various DNA motif discovery algorithms and automatically merges redundant motifs from multiple training sets into a coherent annotated library of motifs. Application of this pipeline to recent genome-wide transcription factor location data in S. cerevisiae successfully identified DNA motifs in a manner that is as good as semi-automated analysis reported in the literature. Moreover, we show how this analysis elucidates the mechanisms of condition-specific preferences of transcription factors.

  20. A comparison of the near-infrared spectral features of early-type galaxies in the Coma Cluster, the Virgo cluster and the field

    Science.gov (United States)

    Houdashelt, Mark L.; Frogel, Jay A.

    1993-01-01

    Earlier researchers derived the relative distance between the Coma and Virgo clusters from color-magnitude relations of the early-type galaxies in each cluster. They found that the derived distance was color-dependent and concluded that the galaxies of similar luminosity in the two clusters differ in their red stellar populations. More recently, the color-dependence of the Coma-Virgo distance modulus has been called into question. However, because these two clusters differ so dramatically in their morphologies and kinematics, it is plausible that the star formation histories of the member galaxies also differed. If the conclusions of earlier researchers are indeed correct, then some signature of the resulting stellar population differences should appear in the near-infrared and/or infrared light of the respective galaxies. We have collected near-infrared spectra of 17 Virgo and 10 Coma early-type galaxies; this sample spans about four magnitudes in luminosity in each cluster. Seven field E/S0 galaxies have been observed for comparison. Pseudo-equivalent widths have been measured for all of the field galaxies, all but one of the Virgo members, and five of the Coma galaxies. The features examined are sensitive to the temperature, metallicity, and surface gravity of the reddest stars. A preliminary analysis of these spectral features has been performed, and, with a few notable exceptions, the measured pseudo-equivalent widths agree well with previously published values.

  1. On culture and human development: Interview with Barbara Rogoff

    DEFF Research Database (Denmark)

    Glaveanu, Vlad Petre

    2011-01-01

    In this interview Professor Barbara Rogoff explores the many ways in which culture shapes the course of human development, and illustrates this with several findings from her past as well as most recent work. These reveal the vital importance of growing up in a family and a community for the human...... child and participating, from early on, in their various rituals and practices. Building on and enriching cultural psychological sources, Professor Rogoff offers us a comprehensive framework with which to understand both cultural and developmental phenomena and, above all, their multiple intersections...

  2. BlastNeuron for Automated Comparison, Retrieval and Clustering of 3D Neuron Morphologies.

    Science.gov (United States)

    Wan, Yinan; Long, Fuhui; Qu, Lei; Xiao, Hang; Hawrylycz, Michael; Myers, Eugene W; Peng, Hanchuan

    2015-10-01

    Characterizing the identity and types of neurons in the brain, as well as their associated function, requires a means of quantifying and comparing 3D neuron morphology. Presently, neuron comparison methods are based on statistics from neuronal morphology such as size and number of branches, which are not fully suitable for detecting local similarities and differences in the detailed structure. We developed BlastNeuron to compare neurons in terms of their global appearance, detailed arborization patterns, and topological similarity. BlastNeuron first compares and clusters 3D neuron reconstructions based on global morphology features and moment invariants, independent of their orientations, sizes, level of reconstruction and other variations. Subsequently, BlastNeuron performs local alignment between any pair of retrieved neurons via a tree-topology driven dynamic programming method. A 3D correspondence map can thus be generated at the resolution of single reconstruction nodes. We applied BlastNeuron to three datasets: (1) 10,000+ neuron reconstructions from a public morphology database, (2) 681 newly and manually reconstructed neurons, and (3) neurons reconstructions produced using several independent reconstruction methods. Our approach was able to accurately and efficiently retrieve morphologically and functionally similar neuron structures from large morphology database, identify the local common structures, and find clusters of neurons that share similarities in both morphology and molecular profiles.

  3. Comparison of three methods for the estimation of cross-shock electric potential using Cluster data

    Directory of Open Access Journals (Sweden)

    A. P. Dimmock

    2011-05-01

    Full Text Available Cluster four point measurements provide a comprehensive dataset for the separation of temporal and spatial variations, which is crucial for the calculation of the cross shock electrostatic potential using electric field measurements. While Cluster is probably the most suited among present and past spacecraft missions to provide such a separation at the terrestrial bow shock, it is far from ideal for a study of the cross shock potential, since only 2 components of the electric field are measured in the spacecraft spin plane. The present paper is devoted to the comparison of 3 different techniques that can be used to estimate the potential with this limitation. The first technique is the estimate taking only into account the projection of the measured components onto the shock normal. The second uses the ideal MHD condition E·B = 0 to estimate the third electric field component. The last method is based on the structure of the electric field in the Normal Incidence Frame (NIF for which only the potential component along the shock normal and the motional electric field exist. All 3 approaches are used to estimate the potential for a single crossing of the terrestrial bow shock that took place on the 31 March 2001. Surprisingly all three methods lead to the same order of magnitude for the cross shock potential. It is argued that the third method must lead to more reliable results. The effect of the shock normal inaccuracy is investigated for this particular shock crossing. The resulting electrostatic potential appears too high in comparison with the theoretical results for low Mach number shocks. This shows the variability of the potential, interpreted in the frame of the non-stationary shock model.

  4. Morphometric traits of gizzard in relation to feeding habits of wild Sardinian partridges (Alectoris barbara barbara, Bonnaterre, 1790) with particular regard to clast selection.

    Science.gov (United States)

    Cappai, M G; Arru, G; Manconi, M; Muzzeddu, M; Pinna, W

    2017-06-01

    Housing and feeding practices of wild birds for conservation management of biodiversity or restocking play a crucial role in determining the survival rates of animals when released into nature. Failure in coping with the environment might be one of the main flaws captive animals can experience when put into natural habitat. The present investigation aimed at exploring feeding habits and related morphometric traits of gizzard with respective content from wild partridges in comparison with captive ones. A total of 52 hunted wild Sardinian adult partridges (Alectoris barbara barbara Bonnaterre, 1790) were used. By comparison, 42 captive adult partridges reared in cages were enrolled. From each animal, the morphology of gizzard was investigated and respective content analysed for gross composition and taxonomical determination of fractions. Wet sieving analysis of each gizzard content was carried out (four-sieve towers with different mesh sizes: 1 mm, 500 μm, 250 μm and 125 μm), and relative and absolute weight of fresh filled and empty gizzards were recorded. Thickness of muscular layer of gizzard wall was measured by stereomicroscope. Carcass weight significantly (p wild partridges (478 ± 21 and 305 ± 35 g respectively). Post-mortem inspection highlighted gross morphological differences of gizzards between the two groups. Fresh weight of empty gizzards was 6.37 ± 0.80 vs. 11.25 ± 1.82 g, with average pH values of digesta 4.97 ± 0.11 vs. 4.38 ± 0.28 in captive vs. wild partridges respectively. Gizzard content from wild partridges accounted a 61.7% vs. 38.3% of biological vs. non-biological material proportions (DM basis). The non-biological material was mostly represented by lithic fragments and minerals (quartz, feldspar, calcite and mica) with specific peculiarities in terms of granulometry and morphometry. Feeding the captive partridges should point to support morphological and functional adaptation of gizzards to the feeding stuffs

  5. Comparison between XAS, AWAXS and DAFS applied to nanometer scale supported metallic clusters. Pt.1; monometallic clusters

    International Nuclear Information System (INIS)

    Bazin, D.C.; Sayers, D.A.

    1993-01-01

    The structural information found using three techniques related to synchrotron radiation are compared. XAS (X-ray Absorption Spectroscopy), AWAXS (Anomalous Wide Angle X-ray Scattering) and DAFS (Diffraction Anomalous Fine Structure) are applied to nanometer scale metallic clusters. (author)

  6. Comparison between XAS, AWAXS and DAFS applied to nanometer scale supported metallic clusters. Pt.2; bimetallic clusters

    International Nuclear Information System (INIS)

    Bazin, D.; Sayers, D.

    1993-01-01

    The structural information obtained using three techniques related to synchrotron radiation are compared. XAS (X-ray Absorption Spectroscopy), AWAXS (Anomalous Wide Angle X-ray Scattering) and DAFS (Diffraction Anomalous Fine Structure) are applied to the study of nanometer scale bimetallic clusters. (author)

  7. 33 CFR 167.451 - In the Santa Barbara Channel: Between Point Vicente and Point Conception.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false In the Santa Barbara Channel: Between Point Vicente and Point Conception. 167.451 Section 167.451 Navigation and Navigable Waters COAST....451 In the Santa Barbara Channel: Between Point Vicente and Point Conception. (a) A separation zone is...

  8. 76 FR 31242 - Revisions to the California State Implementation Plan, Santa Barbara County Air Pollution Control...

    Science.gov (United States)

    2011-05-31

    ... the California State Implementation Plan, Santa Barbara County Air Pollution Control District AGENCY... limited disapproval of revisions to the Santa Barbara County Air Pollution Control District (SBCAPCD... BTU/hr and internal combustion engines with a rated brake horse power of 50 or greater. Under...

  9. Barbara Kavemann, Heike Rabe (Hg.: Das Prostitutionsgesetz. Aktuelle Forschungsergebnisse, Umsetzung und Weiterentwicklung. Opladen u.a.: Verlag Barbara Budrich 2009.

    Directory of Open Access Journals (Sweden)

    Ulrike Lembke

    2010-03-01

    Full Text Available Der von Barbara Kavemann und Heike Rabe herausgegebene Sammelband zum Prostitutionsgesetz zeichnet sich dadurch aus, dass die Thematik aus verschiedensten Blickwinkeln beleuchtet wird und insbesondere auch jene zu Wort kommen, die in der medialen Debatte oft keine Stimme haben: Prostituierte in sehr unterschiedlichen Lebens- und Arbeitssituationen ebenso wie Bordellbetreiber/-innen, Praktiker/-innen aus der Sozialen Arbeit ebenso wie aus Verwaltung und Justiz. Dadurch gelingt es, ein differenziertes und realistisches Bild von Prostitution und ihrer Regulierung in Deutschland zu zeichnen sowie weitere Hilfs- und Handlungsbedarfe überzeugend aufzuzeigen, aber auch wegweisende Modelle aus der Praxis vorzustellen.The collected volume on prostitution law, edited by Barbara Kavemann and Heike Rabe, is unique in its discussion of the topic from a variety of perspectives. It allows particularly those perspectives to come to the fore that often do not have a voice in the media debates, including prostitutes in very different life and work situations as well as brothel managers and practitioners from the areas of social work, administration, and justice. In so doing, the editors convincingly portray a differentiated and realistic image of prostitution and its regulation in Germany as well as identify areas of need for further help and action. They also offer up groundbreaking praxis-based models.

  10. A comparison of three clustering methods for finding subgroups in MRI, SMS or clinical data: SPSS TwoStep Cluster analysis, Latent Gold and SNOB.

    Science.gov (United States)

    Kent, Peter; Jensen, Rikke K; Kongsted, Alice

    2014-10-02

    There are various methodological approaches to identifying clinically important subgroups and one method is to identify clusters of characteristics that differentiate people in cross-sectional and/or longitudinal data using Cluster Analysis (CA) or Latent Class Analysis (LCA). There is a scarcity of head-to-head comparisons that can inform the choice of which clustering method might be suitable for particular clinical datasets and research questions. Therefore, the aim of this study was to perform a head-to-head comparison of three commonly available methods (SPSS TwoStep CA, Latent Gold LCA and SNOB LCA). The performance of these three methods was compared: (i) quantitatively using the number of subgroups detected, the classification probability of individuals into subgroups, the reproducibility of results, and (ii) qualitatively using subjective judgments about each program's ease of use and interpretability of the presentation of results.We analysed five real datasets of varying complexity in a secondary analysis of data from other research projects. Three datasets contained only MRI findings (n = 2,060 to 20,810 vertebral disc levels), one dataset contained only pain intensity data collected for 52 weeks by text (SMS) messaging (n = 1,121 people), and the last dataset contained a range of clinical variables measured in low back pain patients (n = 543 people). Four artificial datasets (n = 1,000 each) containing subgroups of varying complexity were also analysed testing the ability of these clustering methods to detect subgroups and correctly classify individuals when subgroup membership was known. The results from the real clinical datasets indicated that the number of subgroups detected varied, the certainty of classifying individuals into those subgroups varied, the findings had perfect reproducibility, some programs were easier to use and the interpretability of the presentation of their findings also varied. The results from the artificial datasets

  11. DNA familial binding profiles made easy: comparison of various motif alignment and clustering strategies.

    Science.gov (United States)

    Mahony, Shaun; Auron, Philip E; Benos, Panayiotis V

    2007-03-30

    Transcription factor (TF) proteins recognize a small number of DNA sequences with high specificity and control the expression of neighbouring genes. The evolution of TF binding preference has been the subject of a number of recent studies, in which generalized binding profiles have been introduced and used to improve the prediction of new target sites. Generalized profiles are generated by aligning and merging the individual profiles of related TFs. However, the distance metrics and alignment algorithms used to compare the binding profiles have not yet been fully explored or optimized. As a result, binding profiles depend on TF structural information and sometimes may ignore important distinctions between subfamilies. Prediction of the identity or the structural class of a protein that binds to a given DNA pattern will enhance the analysis of microarray and ChIP-chip data where frequently multiple putative targets of usually unknown TFs are predicted. Various comparison metrics and alignment algorithms are evaluated (a total of 105 combinations). We find that local alignments are generally better than global alignments at detecting eukaryotic DNA motif similarities, especially when combined with the sum of squared distances or Pearson's correlation coefficient comparison metrics. In addition, multiple-alignment strategies for binding profiles and tree-building methods are tested for their efficiency in constructing generalized binding models. A new method for automatic determination of the optimal number of clusters is developed and applied in the construction of a new set of familial binding profiles which improves upon TF classification accuracy. A software tool, STAMP, is developed to host all tested methods and make them publicly available. This work provides a high quality reference set of familial binding profiles and the first comprehensive platform for analysis of DNA profiles. Detecting similarities between DNA motifs is a key step in the comparative study

  12. DNA familial binding profiles made easy: comparison of various motif alignment and clustering strategies.

    Directory of Open Access Journals (Sweden)

    Shaun Mahony

    2007-03-01

    Full Text Available Transcription factor (TF proteins recognize a small number of DNA sequences with high specificity and control the expression of neighbouring genes. The evolution of TF binding preference has been the subject of a number of recent studies, in which generalized binding profiles have been introduced and used to improve the prediction of new target sites. Generalized profiles are generated by aligning and merging the individual profiles of related TFs. However, the distance metrics and alignment algorithms used to compare the binding profiles have not yet been fully explored or optimized. As a result, binding profiles depend on TF structural information and sometimes may ignore important distinctions between subfamilies. Prediction of the identity or the structural class of a protein that binds to a given DNA pattern will enhance the analysis of microarray and ChIP-chip data where frequently multiple putative targets of usually unknown TFs are predicted. Various comparison metrics and alignment algorithms are evaluated (a total of 105 combinations. We find that local alignments are generally better than global alignments at detecting eukaryotic DNA motif similarities, especially when combined with the sum of squared distances or Pearson's correlation coefficient comparison metrics. In addition, multiple-alignment strategies for binding profiles and tree-building methods are tested for their efficiency in constructing generalized binding models. A new method for automatic determination of the optimal number of clusters is developed and applied in the construction of a new set of familial binding profiles which improves upon TF classification accuracy. A software tool, STAMP, is developed to host all tested methods and make them publicly available. This work provides a high quality reference set of familial binding profiles and the first comprehensive platform for analysis of DNA profiles. Detecting similarities between DNA motifs is a key step in the

  13. Laser fluorosensor overflights of the Santa Barbara oil seeps

    International Nuclear Information System (INIS)

    Brown, C. E.; Nelson, R. D.; Fingas, M.

    1997-01-01

    Environment Canada's Laser Environmental Airborne Fluorosensor (LEAF) system was tested in a series of overflights over naturally occurring oil seeps off Santa Barbara, California. The objective was to test the system's ability to detect oil in actual marine environments and to distinguish petroleum oil from biogenic oils released by kelp beds in and around these naturally occurring oil seep areas. High resolution colour reconnaissance camera images and down-looking video images were collected concurrently with the fluorescence data for documentation purposes. Results of the experiment were analyzed in detail. They confirmed the system's ability to produce geo-referenced oil contamination location maps in real-time. The fluorescence data obtained during overflights was most similar to typical crude oil, i. e. the system successfully distinguished between biogenic oil and typical petroleum oil. 9 refs., 1 tab., 3 figs

  14. Comparison of deformation of α- and non α-cluster systems

    International Nuclear Information System (INIS)

    Kundu, S.; Bhattacharya, C.; Bhattacharya, S.

    2014-01-01

    In the present study, our aim is to see whether α-clustering is the only reason for large deformation in such systems. For this purpose the deformations of several α-cluster and non-α-cluster systems have been recalculated from LCP spectra using statistical model calculation

  15. A comparison of heuristic and model-based clustering methods for dietary pattern analysis.

    Science.gov (United States)

    Greve, Benjamin; Pigeot, Iris; Huybrechts, Inge; Pala, Valeria; Börnhorst, Claudia

    2016-02-01

    Cluster analysis is widely applied to identify dietary patterns. A new method based on Gaussian mixture models (GMM) seems to be more flexible compared with the commonly applied k-means and Ward's method. In the present paper, these clustering approaches are compared to find the most appropriate one for clustering dietary data. The clustering methods were applied to simulated data sets with different cluster structures to compare their performance knowing the true cluster membership of observations. Furthermore, the three methods were applied to FFQ data assessed in 1791 children participating in the IDEFICS (Identification and Prevention of Dietary- and Lifestyle-Induced Health Effects in Children and Infants) Study to explore their performance in practice. The GMM outperformed the other methods in the simulation study in 72 % up to 100 % of cases, depending on the simulated cluster structure. Comparing the computationally less complex k-means and Ward's methods, the performance of k-means was better in 64-100 % of cases. Applied to real data, all methods identified three similar dietary patterns which may be roughly characterized as a 'non-processed' cluster with a high consumption of fruits, vegetables and wholemeal bread, a 'balanced' cluster with only slight preferences of single foods and a 'junk food' cluster. The simulation study suggests that clustering via GMM should be preferred due to its higher flexibility regarding cluster volume, shape and orientation. The k-means seems to be a good alternative, being easier to use while giving similar results when applied to real data.

  16. Spherical Harmonic Analysis of Particle Velocity Distribution Function: Comparison of Moments and Anisotropies using Cluster Data

    Science.gov (United States)

    Gurgiolo, Chris; Vinas, Adolfo F.

    2009-01-01

    This paper presents a spherical harmonic analysis of the plasma velocity distribution function using high-angular, energy, and time resolution Cluster data obtained from the PEACE spectrometer instrument to demonstrate how this analysis models the particle distribution function and its moments and anisotropies. The results show that spherical harmonic analysis produced a robust physical representation model of the velocity distribution function, resolving the main features of the measured distributions. From the spherical harmonic analysis, a minimum set of nine spectral coefficients was obtained from which the moment (up to the heat flux), anisotropy, and asymmetry calculations of the velocity distribution function were obtained. The spherical harmonic method provides a potentially effective "compression" technique that can be easily carried out onboard a spacecraft to determine the moments and anisotropies of the particle velocity distribution function for any species. These calculations were implemented using three different approaches, namely, the standard traditional integration, the spherical harmonic (SPH) spectral coefficients integration, and the singular value decomposition (SVD) on the spherical harmonic methods. A comparison among the various methods shows that both SPH and SVD approaches provide remarkable agreement with the standard moment integration method.

  17. A comparison of IQ and memory cluster solutions in moderate and severe pediatric traumatic brain injury.

    Science.gov (United States)

    Thaler, Nicholas S; Terranova, Jennifer; Turner, Alisa; Mayfield, Joan; Allen, Daniel N

    2015-01-01

    Recent studies have examined heterogeneous neuropsychological outcomes in childhood traumatic brain injury (TBI) using cluster analysis. These studies have identified homogeneous subgroups based on tests of IQ, memory, and other cognitive abilities that show some degree of association with specific cognitive, emotional, and behavioral outcomes, and have demonstrated that the clusters derived for children with TBI are different from those observed in normal populations. However, the extent to which these subgroups are stable across abilities has not been examined, and this has significant implications for the generalizability and clinical utility of TBI clusters. The current study addressed this by comparing IQ and memory profiles of 137 children who sustained moderate-to-severe TBI. Cluster analysis of IQ and memory scores indicated that a four-cluster solution was optimal for the IQ scores and a five-cluster solution was optimal for the memory scores. Three clusters on each battery differed primarily by level of performance, while the others had pattern variations. Cross-plotting the clusters across respective IQ and memory test scores indicated that clusters defined by level were generally stable, while clusters defined by pattern differed. Notably, children with slower processing speed exhibited low-average to below-average performance on memory indexes. These results provide some support for the stability of previously identified memory and IQ clusters and provide information about the relationship between IQ and memory in children with TBI.

  18. High reactivity of nanosized niobium oxide cluster cations in methane activation: A comparison with vanadium oxides.

    Science.gov (United States)

    Ding, Xun-Lei; Wang, Dan; Wu, Xiao-Nan; Li, Zi-Yu; Zhao, Yan-Xia; He, Sheng-Gui

    2015-09-28

    The reactions between methane and niobium oxide cluster cations were studied and compared to those employing vanadium oxides. Hydrogen atom abstraction (HAA) reactions were identified over stoichiometric (Nb2O5)N(+) clusters for N as large as 14 with a time-of-flight mass spectrometer. The reactivity of (Nb2O5)N(+) clusters decreases as the N increases, and it is higher than that of (V 2O5)N(+) for N ≥ 4. Theoretical studies were conducted on (Nb2O5)N(+) (N = 2-6) by density functional calculations. HAA reactions on these clusters are all favorable thermodynamically and kinetically. The difference of the reactivity with respect to the cluster size and metal type (Nb vs V) was attributed to thermodynamics, kinetics, the electron capture ability, and the distribution of the unpaired spin density. Nanosized Nb oxide clusters show higher HAA reactivity than V oxides, indicating that niobia may serve as promising catalysts for practical methane conversion.

  19. Groundwater-quality data in the Santa Barbara study unit, 2011: results from the California GAMA Program

    Science.gov (United States)

    Davis, Tracy A.; Kulongoski, Justin T.; Belitz, Kenneth

    2013-01-01

    Groundwater quality in the 48-square-mile Santa Barbara study unit was investigated by the U.S. Geological Survey (USGS) from January to February 2011, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program’s Priority Basin Project (PBP). The GAMA-PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001 and is being conducted in collaboration with the SWRCB and Lawrence Livermore National Laboratory (LLNL). The Santa Barbara study unit was the thirty-fourth study unit to be sampled as part of the GAMA-PBP. The GAMA Santa Barbara study was designed to provide a spatially unbiased assessment of untreated-groundwater quality in the primary aquifer system, and to facilitate statistically consistent comparisons of untreated-groundwater quality throughout California. The primary aquifer system is defined as those parts of the aquifers corresponding to the perforation intervals of wells listed in the California Department of Public Health (CDPH) database for the Santa Barbara study unit. Groundwater quality in the primary aquifer system may differ from the quality in the shallower or deeper water-bearing zones; shallow groundwater may be more vulnerable to surficial contamination. In the Santa Barbara study unit located in Santa Barbara and Ventura Counties, groundwater samples were collected from 24 wells. Eighteen of the wells were selected by using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells), and six wells were selected to aid in evaluation of water-quality issues (understanding wells). The groundwater samples were analyzed for organic constituents (volatile organic compounds [VOCs], pesticides and pesticide degradates, and pharmaceutical compounds); constituents of special interest (perchlorate and N-nitrosodimethylamine [NDMA]); naturally occurring inorganic constituents (trace

  20. Coastal Processes Study of Santa Barbara and Ventura Counties, California

    Science.gov (United States)

    Barnard, Patrick L.; Revell, David L.; Hoover, Dan; Warrick, Jon; Brocatus, John; Draut, Amy E.; Dartnell, Pete; Elias, Edwin; Mustain, Neomi; Hart, Pat E.; Ryan, Holly F.

    2009-01-01

    The Santa Barbara littoral cell (SBLC) is a complex coastal system with significant management challenges. The coastline ranges broadly in exposure to wave energy, fluvial inputs, hard structures, and urbanization. Geologic influence (structural control) on coastline orientation exerts an important control on local beach behavior, with anthropogenic alterations and the episodic nature of sediment supply and transport also playing important roles. Short- and long-term temporal analyses of shoreline change, beach width, and volume change show no obvious trends in regional beach behavior. Extensive armoring along the SBLC has accreted the back beach, narrowing beach widths and in some cases increasing sediment transport. Unarmored beaches have exhibited mild erosion while maintaining similar widths. Harbor constructions have had notable impacts on downdrift beaches, but once the coastal system has equilibrated the signal becomes strongly dampened and littoral-drift gradients driven by natural shoreline orientation again become dominant. Sediment inputs from the Santa Clara River dominate sediment processes on beaches to the south. The SBLC is dominated by episodic flood and storm-wave events. Exceptionally large accretion signals along this stretch of coastline are closely tied to major flood events when large amounts of sediment are deposited in deltas. These deltas decay over time, supplying downdrift beaches with sediment. Storm-wave impacts and gradients in alongshore transport can lead to beach rotations and migrating erosion hotspots when geological controls are weak. Annual and seasonal rates of cross-shore and alongshore transport are at least 2-3 times higher for the more west- and southwest-facing beaches south of the Ventura River as compared to the more sheltered beaches to the west/north. Gross littoral transports are good approximations of net littoral transports for beaches west/north of Ventura as transport is almost purely unidirectional. However

  1. Topografia vertebromedular de irara (Eira barbara Linnaeus, 1758

    Directory of Open Access Journals (Sweden)

    Marta Adami

    2015-10-01

    Full Text Available Resumo: Um cadáver macho, adulto de irara (Eira barbara foi cedido pelo Centro de Triagem de Animais Silvestres (Cetas, localizado em Salvador/Bahia, ao Setor de Anatomia Veterinária da Escola de Medicina Veterinária e Zootecnia da Universidade Federal da Bahia. Trata-se de um mamífero carnívoro que pertence à Família Mustelidae e Subfamília Mustelinae que contém o Gênero Eira, representado apenas pela Espécie Eira barbara. Objetivamos a investigação da topografia vertebromedular do espécime e assim verificar a relação da medula espinal com o canal vertebral; a identificação, origem, emergência e quantificação dos nervos espinhais relacionados com a medula espinal. Pesquisa número 43245-1 autorizada pelo Sistema de Autorização e Informação em Biodiversidade (Sisbio-ICMBio/IBAMA. O exemplar foi fixado em solução de formaldeído a 10% e posteriormente dissecado e radiografado. Foram identificados oito pares de nervos espinhais cervicais, quatorze torácicos e na porção lombossacral da medula espinhal seis nervos espinais lombares, três sacrais e mais de três nervos espinhais caudais. O término da medula espinal ocorreu no nível quinta vértebra lombar. Os oito segmentos medulares cervicais localizaram-se entre a primeira e sétima vértebras cervicais. Os quatorze nervos espinais torácicos originaram-se na porção cranial das vértebras respectivas. Os segmentos medulares lombares, sacrais e caudais restringiram-se à região lombar da coluna vertebral. O deslocamento cranial dos segmentos medulares foi observado no oitavo cervical, terceiro, quarto e quinto lombares e todos os segmentos sacrais e caudais. As informações obtidas poderão ser utilizadas para análises comparativas com as demais espécies e com a adoção de medidas que visem proporcionar o bem-estar animal e a preservação da espécie.

  2. A Comparison between Standard and Functional Clustering Methodologies: Application to Agricultural Fields for Yield Pattern Assessment

    Directory of Open Access Journals (Sweden)

    Simone Pascucci

    2018-04-01

    Full Text Available The recognition of spatial patterns within agricultural fields, presenting similar yield potential areas, stable through time, is very important for optimizing agricultural practices. This study proposes the evaluation of different clustering methodologies applied to multispectral satellite time series for retrieving temporally stable (constant patterns in agricultural fields, related to within-field yield spatial distribution. The ability of different clustering procedures for the recognition and mapping of constant patterns in fields of cereal crops was assessed. Crop vigor patterns, considered to be related to soils characteristics, and possibly indicative of yield potential, were derived by applying the different clustering algorithms to time series of Landsat images acquired on 94 agricultural fields near Rome (Italy. Two different approaches were applied and validated using Landsat 7 and 8 archived imagery. The first approach automatically extracts and calculates for each field of interest (FOI the Normalized Difference Vegetation Index (NDVI, then exploits the standard K-means clustering algorithm to derive constant patterns at the field level. The second approach applies novel clustering procedures directly to spectral reflectance time series, in particular: (1 standard K-means; (2 functional K-means; (3 multivariate functional principal components clustering analysis; (4 hierarchical clustering. The different approaches were validated through cluster accuracy estimates on a reference set of FOIs for which yield maps were available for some years. Results show that multivariate functional principal components clustering, with an a priori determination of the optimal number of classes for each FOI, provides a better accuracy than those of standard clustering algorithms. The proposed novel functional clustering methodologies are effective and efficient for constant pattern retrieval and can be used for a sustainable management of

  3. Internal validation of risk models in clustered data: a comparison of bootstrap schemes

    NARCIS (Netherlands)

    Bouwmeester, W.; Moons, K.G.M.; Kappen, T.H.; van Klei, W.A.; Twisk, J.W.R.; Eijkemans, M.J.C.; Vergouwe, Y.

    2013-01-01

    Internal validity of a risk model can be studied efficiently with bootstrapping to assess possible optimism in model performance. Assumptions of the regular bootstrap are violated when the development data are clustered. We compared alternative resampling schemes in clustered data for the estimation

  4. Comparison of Hydrogen Elimination from Molecular Zinc and Magnesium Hydride Clusters

    NARCIS (Netherlands)

    Intemann, J.; Sirsch, Peter; Harder, Sjoerd

    2014-01-01

    In analogy to the previously reported tetranuclear magnesium hydride cluster with a bridged dianionic bis-beta-diketiminate ligand, a related zinc hydride cluster has been prepared. The crystal structures of these magnesium and zinc hydride complexes are similar: the metal atoms are situated at the

  5. Comparison of clustering methods for tracking features in RGB-D images

    CSIR Research Space (South Africa)

    Pancham, Ardhisha

    2016-10-01

    Full Text Available and the performance of k-means, mean shift, a contrario, Density-Based Spatial Clustering of Applications with Noise (DBSCAN), and Gaussian Mixture Models (GMM) clustering algorithms are validated in tests with synthetic and RGB-D data. Results indicate that mean...

  6. Comparison of Clustering Techniques for Residential Energy Behavior using Smart Meter Data

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Ling; Lee, Doris; Sim, Alex; Borgeson, Sam; Wu, Kesheng; Spurlock, C. Anna; Todd, Annika

    2017-03-21

    Current practice in whole time series clustering of residential meter data focuses on aggregated or subsampled load data at the customer level, which ignores day-to-day differences within customers. This information is critical to determine each customer’s suitability to various demand side management strategies that support intelligent power grids and smart energy management. Clustering daily load shapes provides fine-grained information on customer attributes and sources of variation for subsequent models and customer segmentation. In this paper, we apply 11 clustering methods to daily residential meter data. We evaluate their parameter settings and suitability based on 6 generic performance metrics and post-checking of resulting clusters. Finally, we recommend suitable techniques and parameters based on the goal of discovering diverse daily load patterns among residential customers. To the authors’ knowledge, this paper is the first robust comparative review of clustering techniques applied to daily residential load shape time series in the power systems’ literature.

  7. Parim Claptoni jäljendaja Eestis. Barbara Hendricks Pärnus Promfestil

    Index Scriptorium Estoniae

    2007-01-01

    Eric Claptoni tribuutbändi Classic Clapton kontsertidest 4. ja 5. apr. Tartus ja Tallinnas. Ameerika laulja Barbara Hendricksi kontserdist 7. juunil Pärnu Kontserdimajas (kaastegev rootsi pianist Love Derwinger)

  8. Reply to Barbara Pfeffer Billauer's "On Judaism and genes.

    Science.gov (United States)

    Wolpe, Paul Root

    1999-06-01

    The response of Barbara Pfeffer Billauer to my article "If I Am Only My Genes, What Am I? Genetic Essentialism and a Jewish Response" highlights the conflict between a sociological understanding of religion and the resistance to such analysis from within a faith tradition. Ms. Billauer makes three main points; the first strangely credits to me, and then attacks, an argument the article takes great pains to refute, but does so to emphasize the faith's prescient guidance in matters scientific. The second attempts to rebut my critical analysis of the tensions inhernet in Jewish views of the body with an insistence that Judaism so perfectly balances the relation between the sacred and profane that there is not now, and never was, the slightest tension between corporeality and divinity in the Jewish corpus. The third uses my article as vehicle for her to expound on an interesting but tangential formulation of three Jewish terms. In all, the need to defend her interpretation of Judaism's solutions to the problems the article raises results in un-self-critical and ahistorical theorizing, making the utility of her arguments in a discussion of the sociology of religion unsatisfactory.

  9. Comparison of tests for spatial heterogeneity on data with global clustering patterns and outliers

    Directory of Open Access Journals (Sweden)

    Hachey Mark

    2009-10-01

    Full Text Available Abstract Background The ability to evaluate geographic heterogeneity of cancer incidence and mortality is important in cancer surveillance. Many statistical methods for evaluating global clustering and local cluster patterns are developed and have been examined by many simulation studies. However, the performance of these methods on two extreme cases (global clustering evaluation and local anomaly (outlier detection has not been thoroughly investigated. Methods We compare methods for global clustering evaluation including Tango's Index, Moran's I, and Oden's I*pop; and cluster detection methods such as local Moran's I and SaTScan elliptic version on simulated count data that mimic global clustering patterns and outliers for cancer cases in the continental United States. We examine the power and precision of the selected methods in the purely spatial analysis. We illustrate Tango's MEET and SaTScan elliptic version on a 1987-2004 HIV and a 1950-1969 lung cancer mortality data in the United States. Results For simulated data with outlier patterns, Tango's MEET, Moran's I and I*pop had powers less than 0.2, and SaTScan had powers around 0.97. For simulated data with global clustering patterns, Tango's MEET and I*pop (with 50% of total population as the maximum search window had powers close to 1. SaTScan had powers around 0.7-0.8 and Moran's I has powers around 0.2-0.3. In the real data example, Tango's MEET indicated the existence of global clustering patterns in both the HIV and lung cancer mortality data. SaTScan found a large cluster for HIV mortality rates, which is consistent with the finding from Tango's MEET. SaTScan also found clusters and outliers in the lung cancer mortality data. Conclusion SaTScan elliptic version is more efficient for outlier detection compared with the other methods evaluated in this article. Tango's MEET and Oden's I*pop perform best in global clustering scenarios among the selected methods. The use of SaTScan for

  10. Metagenomes from two microbial consortia associated with Santa Barbara seep oil.

    Science.gov (United States)

    Hawley, Erik R; Malfatti, Stephanie A; Pagani, Ioanna; Huntemann, Marcel; Chen, Amy; Foster, Brian; Copeland, Alexander; del Rio, Tijana Glavina; Pati, Amrita; Jansson, Janet R; Gilbert, Jack A; Tringe, Susannah Green; Lorenson, Thomas D; Hess, Matthias

    2014-12-01

    The metagenomes from two microbial consortia associated with natural oils seeping into the Pacific Ocean offshore the coast of Santa Barbara (California, USA) were determined to complement already existing metagenomes generated from microbial communities associated with hydrocarbons that pollute the marine ecosystem. This genomics resource article is the first of two publications reporting a total of four new metagenomes from oils that seep into the Santa Barbara Channel. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. A Comparison Study of Validity Indices on Swarm-Intelligence-Based Clustering.

    Science.gov (United States)

    Rui Xu; Jie Xu; Wunsch, D C

    2012-08-01

    Swarm intelligence has emerged as a worthwhile class of clustering methods due to its convenient implementation, parallel capability, ability to avoid local minima, and other advantages. In such applications, clustering validity indices usually operate as fitness functions to evaluate the qualities of the obtained clusters. However, as the validity indices are usually data dependent and are designed to address certain types of data, the selection of different indices as the fitness functions may critically affect cluster quality. Here, we compare the performances of eight well-known and widely used clustering validity indices, namely, the Caliński-Harabasz index, the CS index, the Davies-Bouldin index, the Dunn index with two of its generalized versions, the I index, and the silhouette statistic index, on both synthetic and real data sets in the framework of differential-evolution-particle-swarm-optimization (DEPSO)-based clustering. DEPSO is a hybrid evolutionary algorithm of the stochastic optimization approach (differential evolution) and the swarm intelligence method (particle swarm optimization) that further increases the search capability and achieves higher flexibility in exploring the problem space. According to the experimental results, we find that the silhouette statistic index stands out in most of the data sets that we examined. Meanwhile, we suggest that users reach their conclusions not just based on only one index, but after considering the results of several indices to achieve reliable clustering structures.

  12. A comparison of Fe 4 S 4 clusters in high-potential iron protein and in ferredoxin.

    Science.gov (United States)

    Carter, C W; Kraut, J; Freer, S T; Alden, R A; Sieker, L C; Adman, E; Jensen, L H

    1972-12-01

    The structures of both oxidized (HP(ox)) and reduced (HP(red)) high-potential iron protein and of oxidized ferredoxin (Fd(ox)) have been partially refined at 2.0-A resolution by methods similar to those applied to the protein rubredoxin [Watenpaugh, K. D., Sieker, L. C., Herriott, J. R. & Jensen, L. H. (1971) Cold Spring Harbor Symp. Quant. Biol. 36, 359-367]. Average bond lengths and angles in the HP(red) and Fd(ox) Fe(4)S(4) (*) clusters are the same to within the root-mean square (rms) deviation of each mean value. A preliminary comparison of the two HiPIP oxidation states indicates that the HP(ox) cluster is geometrically similar to the HP(red) cluster, but that it is smaller by 0.1-0.2 A in certain dimensions. The HiPIP and ferredoxin cluster geometry is also nearly identical to that reported recently for a synthetic analog [Herskovitz, T., Averill, B. A., Holm, R. A., Ibers, J. A., Phillips, W. D. & Weither, J. F. (1972) Proc. Nat. Acad. Sci. USA 69, 2437-2441]. An apparent paradox presented by the large difference between the HiPIP and ferredoxin electrode potentials can be resolved by the assumption that the Fe(4)S(4) (*) cluster has not two but three oxidation states. The fully oxidized (HP(ox)) and fully reduced (Fd(red)) clusters are paramagnetic, and the intermediate state is spin-paired [Tsibris, J. C. M. and Woody, R. W. (1970) Coord. Chem. Rev. 5, 417-458]. This hypothesis is supported by structural and spectroscopic evidence that the "paired-spin" state exists in both HP(red) and Fd(ox).

  13. A comparison of latent class, K-means, and K-median methods for clustering dichotomous data.

    Science.gov (United States)

    Brusco, Michael J; Shireman, Emilie; Steinley, Douglas

    2017-09-01

    The problem of partitioning a collection of objects based on their measurements on a set of dichotomous variables is a well-established problem in psychological research, with applications including clinical diagnosis, educational testing, cognitive categorization, and choice analysis. Latent class analysis and K-means clustering are popular methods for partitioning objects based on dichotomous measures in the psychological literature. The K-median clustering method has recently been touted as a potentially useful tool for psychological data and might be preferable to its close neighbor, K-means, when the variable measures are dichotomous. We conducted simulation-based comparisons of the latent class, K-means, and K-median approaches for partitioning dichotomous data. Although all 3 methods proved capable of recovering cluster structure, K-median clustering yielded the best average performance, followed closely by latent class analysis. We also report results for the 3 methods within the context of an application to transitive reasoning data, in which it was found that the 3 approaches can exhibit profound differences when applied to real data. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  14. A comparison of two suffix tree-based document clustering algorithms

    OpenAIRE

    Rafi, Muhammad; Maujood, M.; Fazal, M. M.; Ali, S. M.

    2011-01-01

    Document clustering as an unsupervised approach extensively used to navigate, filter, summarize and manage large collection of document repositories like the World Wide Web (WWW). Recently, focuses in this domain shifted from traditional vector based document similarity for clustering to suffix tree based document similarity, as it offers more semantic representation of the text present in the document. In this paper, we compare and contrast two recently introduced approaches to document clus...

  15. UPDATED MASS SCALING RELATIONS FOR NUCLEAR STAR CLUSTERS AND A COMPARISON TO SUPERMASSIVE BLACK HOLES

    International Nuclear Information System (INIS)

    Scott, Nicholas; Graham, Alister W.

    2013-01-01

    We investigate whether or not nuclear star clusters and supermassive black holes (SMBHs) follow a common set of mass scaling relations with their host galaxy's properties, and hence can be considered to form a single class of central massive object (CMO). We have compiled a large sample of galaxies with measured nuclear star cluster masses and host galaxy properties from the literature and fit log-linear scaling relations. We find that nuclear star cluster mass, M NC , correlates most tightly with the host galaxy's velocity dispersion: log M NC = (2.11 ± 0.31)log (σ/54) + (6.63 ± 0.09), but has a slope dramatically shallower than the relation defined by SMBHs. We find that the nuclear star cluster mass relations involving host galaxy (and spheroid) luminosity and stellar and dynamical mass, intercept with but are in general shallower than the corresponding black hole scaling relations. In particular, M NC ∝M 0.55±0.15 Gal,dyn ; the nuclear cluster mass is not a constant fraction of its host galaxy or spheroid mass. We conclude that nuclear stellar clusters and SMBHs do not form a single family of CMOs.

  16. Relation between financial market structure and the real economy: comparison between clustering methods.

    Science.gov (United States)

    Musmeci, Nicoló; Aste, Tomaso; Di Matteo, T

    2015-01-01

    We quantify the amount of information filtered by different hierarchical clustering methods on correlations between stock returns comparing the clustering structure with the underlying industrial activity classification. We apply, for the first time to financial data, a novel hierarchical clustering approach, the Directed Bubble Hierarchical Tree and we compare it with other methods including the Linkage and k-medoids. By taking the industrial sector classification of stocks as a benchmark partition, we evaluate how the different methods retrieve this classification. The results show that the Directed Bubble Hierarchical Tree can outperform other methods, being able to retrieve more information with fewer clusters. Moreover,we show that the economic information is hidden at different levels of the hierarchical structures depending on the clustering method. The dynamical analysis on a rolling window also reveals that the different methods show different degrees of sensitivity to events affecting financial markets, like crises. These results can be of interest for all the applications of clustering methods to portfolio optimization and risk hedging [corrected].

  17. Comparison of Bayesian clustering and edge detection methods for inferring boundaries in landscape genetics

    Science.gov (United States)

    Safner, T.; Miller, M.P.; McRae, B.H.; Fortin, M.-J.; Manel, S.

    2011-01-01

    Recently, techniques available for identifying clusters of individuals or boundaries between clusters using genetic data from natural populations have expanded rapidly. Consequently, there is a need to evaluate these different techniques. We used spatially-explicit simulation models to compare three spatial Bayesian clustering programs and two edge detection methods. Spatially-structured populations were simulated where a continuous population was subdivided by barriers. We evaluated the ability of each method to correctly identify boundary locations while varying: (i) time after divergence, (ii) strength of isolation by distance, (iii) level of genetic diversity, and (iv) amount of gene flow across barriers. To further evaluate the methods' effectiveness to detect genetic clusters in natural populations, we used previously published data on North American pumas and a European shrub. Our results show that with simulated and empirical data, the Bayesian spatial clustering algorithms outperformed direct edge detection methods. All methods incorrectly detected boundaries in the presence of strong patterns of isolation by distance. Based on this finding, we support the application of Bayesian spatial clustering algorithms for boundary detection in empirical datasets, with necessary tests for the influence of isolation by distance. ?? 2011 by the authors; licensee MDPI, Basel, Switzerland.

  18. Gas stripping and mixing in galaxy clusters: a numerical comparison study

    Science.gov (United States)

    Heß, Steffen; Springel, Volker

    2012-11-01

    The ambient hot intrahalo gas in clusters of galaxies is constantly fed and stirred by infalling galaxies, a process that can be studied in detail with cosmological hydrodynamical simulations. However, different numerical methods yield discrepant predictions for crucial hydrodynamical processes, leading for example to different entropy profiles in clusters of galaxies. In particular, the widely used Lagrangian smoothed particle hydrodynamics (SPH) scheme is suspected to strongly damp fluid instabilities and turbulence, which are both crucial to establish the thermodynamic structure of clusters. In this study, we test to which extent our recently developed Voronoi particle hydrodynamics (VPH) scheme yields different results for the stripping of gas out of infalling galaxies and for the bulk gas properties of cluster. We consider both the evolution of isolated galaxy models that are exposed to a stream of intracluster medium or are dropped into cluster models, as well as non-radiative cosmological simulations of cluster formation. We also compare our particle-based method with results obtained with a fundamentally different discretization approach as implemented in the moving-mesh code AREPO. We find that VPH leads to noticeably faster stripping of gas out of galaxies than SPH, in better agreement with the mesh-code than with SPH. We show that despite the fact that VPH in its present form is not as accurate as the moving mesh code in our investigated cases, its improved accuracy of gradient estimates makes VPH an attractive alternative to SPH.

  19. Validation and Application of PHYDOTax In The Santa Barbara Channel

    Science.gov (United States)

    Schafer, C. B.; Palacios, S. L.; Broughton, J.; Kudela, R. M.

    2013-12-01

    Phytoplankton Functional Types(PFTs) are conceptual groupings of phytoplankton based on physical or functional characteristics. Understanding phytoplankton is essential in our study of how ecosystems function and in monitoring carbon flow. PHYDOTax is a PFT algorithm that discriminates taxon-specific biomass in images from airborne and spaceborne hyperspectral sensors. The PHYDOTax algorithm uses a spectral library and an inverse matrix approach to deconvolve pure phytoplankton spectral end-members from spectra of natural waters. The spectral library used in development was created from phytoplankton taxa found in Monterey Bay, CA and the California Current System (CCS). PHYDOTax has only been validated in Monterey Bay and for only one airborne sensor, Spectroscopic Aerial Mapping System with On-board Navigation (SAMSON). The objectives of this research were to apply PHYDOTax to a different region of the CCS, Santa Barbara Channel (SBC), and to test the usability of PHYDOTax with a different airborne imager, Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). PHYDOTax was modified to accommodate the reduced spectral resolution of AVIRIS, which has fewer wavelengths than the SAMSON imagery that was used to validate the model for Monterey Bay. PHYDOTax's predictions were consistent with cell-count data from whole water samples on June 5, 2013, courtesy of the Plumes and Blooms Cruise (UCSB). PHYDOTax's ability to perform in another area of the CCS shows promise that it may be accurately applied to the west coast of the US. PHYDOTax's ability to perform with lower spectral resolution imagery, suggests that it may it may be robust enough to be down-sampled to multi-spectral resolution inputs. This opens the possibility of applying PHYDOTax to historical (SeaWiFS, MODIS, MERIS), existing (VIIRS, HICO), and future (PACE, GEO-CAPE) sensors to describe temporal trends in phytoplankton distribution and carbon flow in the ocean and to build continuity among the sensor

  20. A Conversation with Martin Stannard and Barbara Cooke

    Directory of Open Access Journals (Sweden)

    Annabel Williams

    2016-10-01

    Full Text Available Martin Stannard is Professor of Modern English Literature at the University of Leicester. He read for his first degree in English at Warwick (1967-70, before taking an MA at Sussex University, and a DPhil at Oxford. Professor Stannard’s two-volume literary biography of Evelyn Waugh (1986, 1992, and his biography of Muriel Spark (2009 are essential reading for Waugh and Spark scholars, and are each studies in the value of historical contextualisation for appreciating the literary oeuvre of a writer. Stannard’s 1995 Norton Critical Edition of Ford Madox Ford’s modernist novel, The Good Soldier, similarly brings context to bear through his rigorous textual editing, annotation and critical apparatus. Stannard is currently the Principal Investigator for the Complete Works of Evelyn Waugh project, which is supported by a grant of  £822,000 from the AHRC, and which will see Oxford University Press publish 43 scholarly edition volumes of Waugh – the first of which appears next year. This year marks the fiftieth anniversary of Waugh’s death. Dr Barbara Cooke also teaches at the School of English at the University of Leicester. She received a BA and MA from Warwick (dates, and a PhD in Creative and Critical writing from the University of East Anglia for her interdisciplinary thesis Oil Men: the Twinned Lives of Arnold Wilson and Morris Young. Dr. Cooke is Research Associate for the Complete Works of Evelyn Waugh, providing a vital link between the project's 23 editors, of which she is one, editing Waugh’s autobiography A Little Learning (1964.

  1. Planck intermediate results: II. Comparison of sunyaev-zeldovich measurements from planck and from the arcminute microkelvin imager for 11 galaxy clusters

    DEFF Research Database (Denmark)

    Bucher, M.; Delabrouille, J.; Fromenteau, S.

    2013-01-01

    A comparison is presented of Sunyaev-Zeldovich measurements for 11 galaxy clusters as obtained by Planck and by the ground-based interferometer, the Arcminute Microkelvin Imager. Assuming a universal spherically-symmetric Generalised Navarro, Frenk and White (GNFW) model for the cluster gas...... pressure profile, we jointly constrain the integrated Compton-Y parameter (Y 500) and the scale radius (θ500) of each cluster. Our resulting constraints in the Y500-θ500 2D parameter space derived from the two instruments overlap significantly for eight of the clusters, although, overall...

  2. Comparison of Clustering Algorithms for the Identification of Topics on Twitter

    Directory of Open Access Journals (Sweden)

    Marjori N. M. Klinczak

    2016-05-01

    Full Text Available Topic Identification in Social Networks has become an important task when dealing with event detection, particularly when global communities are affected. In order to attack this problem, text processing techniques and machine learning algorithms have been extensively used. In this paper we compare four clustering algorithms – k-means, k-medoids, DBSCAN and NMF (Non-negative Matrix Factorization – in order to detect topics related to textual messages obtained from Twitter. The algorithms were applied to a database initially composed by tweets having hashtags related to the recent Nepal earthquake as initial context. Obtained results suggest that the NMF clustering algorithm presents superior results, providing simpler clusters that are also easier to interpret.

  3. Analysis of cost data in a cluster-randomized, controlled trial: comparison of methods

    DEFF Research Database (Denmark)

    Sokolowski, Ineta; Ørnbøl, Eva; Rosendal, Marianne

    studies have used non-valid analysis of skewed data. We propose two different methods to compare mean cost in two groups. Firstly, we use a non-parametric bootstrap method where the re-sampling takes place on two levels in order to take into account the cluster effect. Secondly, we proceed with a log......-transformation of the cost data and apply the normal theory on these data. Again we try to account for the cluster effect. The performance of these two methods is investigated in a simulation study. The advantages and disadvantages of the different approaches are discussed.......  We consider health care data from a cluster-randomized intervention study in primary care to test whether the average health care costs among study patients differ between the two groups. The problems of analysing cost data are that most data are severely skewed. Median instead of mean...

  4. Clustering of unhealthy outdoor advertisements around child-serving institutions: a comparison of three cities.

    Science.gov (United States)

    Hillier, Amy; Cole, Brian L; Smith, Tony E; Yancey, Antronette K; Williams, Jerome D; Grier, Sonya A; McCarthy, William J

    2009-12-01

    Using GPS devices and digital cameras, we surveyed outdoor advertisements in Austin, Los Angeles and Philadelphia. GIS and hot spot analysis revealed that unhealthy ads were clustered around child-serving institutions in Los Angeles and Philadelphia but not in Austin. Multivariate generalized least square (GLS) regression models showed that percent black (p<0.04) was a significant positive predictor of clustering in Philadelphia and percent white (p<0.06) was a marginally significant negative predictor of clustering in Los Angeles after controlling for several land use variables. The results emphasize the importance of zoning and land use regulations to protect children from exposure to unhealthy commercial messages, particularly in neighborhoods with significant racial/ethnic minority populations.

  5. Non-stationarity of the quasi-perpendicular bow shock: comparison between Cluster observations and simulations

    Czech Academy of Sciences Publication Activity Database

    Comisel, H.; Scholer, M.; Souček, Jan; Matsukiyo, S.

    2011-01-01

    Roč. 29, č. 2 (2011), s. 263-274 ISSN 0992-7689 Institutional research plan: CEZ:AV0Z30420517 Keywords : bow shock * Cluster * plasma waves * shock waves Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.842, year: 2011 http://www.ann-geophys.net/29/263/2011/angeo-29-263-2011.pdf

  6. Personal Learning Network Clusters: A Comparison between Mathematics and Computer Science Students

    Science.gov (United States)

    Harding, Ansie; Engelbrecht, Johann

    2015-01-01

    "Personal learning environments" (PLEs) and "personal learning networks" (PLNs) are well-known concepts. A personal learning network "cluster" is a small group of people who regularly interact academically and whose PLNs have a non-empty intersection that includes all the other members. At university level PLN…

  7. A comparison of two mass distributions applicable to globular clusters and dwarf galaxies

    Directory of Open Access Journals (Sweden)

    Ninković Slobodan D.

    2004-01-01

    Full Text Available A particular case of mass distribution in stellar systems, already described in the literature, is compared to the King model of mass distribution. For the cases which would correspond to the description of real stellar systems such as the globular clusters and dwarf galaxies, one finds a satisfactory agreement between these two mass distributions.

  8. Comparison of cluster and principal component analysis techniques to derive dietary patterns in Irish adults.

    Science.gov (United States)

    Hearty, Aine P; Gibney, Michael J

    2009-02-01

    The aims of the present study were to examine and compare dietary patterns in adults using cluster and factor analyses and to examine the format of the dietary variables on the pattern solutions (i.e. expressed as grams/day (g/d) of each food group or as the percentage contribution to total energy intake). Food intake data were derived from the North/South Ireland Food Consumption Survey 1997-9, which was a randomised cross-sectional study of 7 d recorded food and nutrient intakes of a representative sample of 1379 Irish adults aged 18-64 years. Cluster analysis was performed using the k-means algorithm and principal component analysis (PCA) was used to extract dietary factors. Food data were reduced to thirty-three food groups. For cluster analysis, the most suitable format of the food-group variable was found to be the percentage contribution to energy intake, which produced six clusters: 'Traditional Irish'; 'Continental'; 'Unhealthy foods'; 'Light-meal foods & low-fat milk'; 'Healthy foods'; 'Wholemeal bread & desserts'. For PCA, food groups in the format of g/d were found to be the most suitable format, and this revealed four dietary patterns: 'Unhealthy foods & high alcohol'; 'Traditional Irish'; 'Healthy foods'; 'Sweet convenience foods & low alcohol'. In summary, cluster and PCA identified similar dietary patterns when presented with the same dataset. However, the two dietary pattern methods required a different format of the food-group variable, and the most appropriate format of the input variable should be considered in future studies.

  9. Petroleum Weathering Associated with Hydrocarbon Migration and Seepage, a Case Study From the Santa Barbara Channel, CA.

    Science.gov (United States)

    Wardlaw, G. D.; Nelson, R. K.; Reddy, C. M.; Valentine, D. L.

    2005-12-01

    A 2003 report by the National Research Council estimates that 50 to 70 percent of oil that is released into the sea is from natural seeps (National Research Council, 2003), indicating that catastrophic oil spills or the runoff from roads and highways are not the major sources of oil in the marine environment. For example, approximately 37 tons of petroleum is emitted daily from seeps off the coast of Santa Barbara, California (Quigley et al. 1996). The Santa Barbara seeps are some of the most active in the world and have been releasing petroleum for thousands of years. Sheens of oil on the water surface and tar patches on the beaches are ubiquitous along the coastline of Santa Barbara and are continuing reminders of this natural process. Although the geochemistry of these seeps have been studied in the past, it has been hindered by the complexity of the petroleum hydrocarbons and the inability of traditional gas chromatography to separate, identify, and quantify each component of the oil. To expand on these previous efforts, we have begun to use comprehensive two-dimensional gas chromatography (GCxGC). This new technology provides at least an order of magnitude increase in the resolution and detection of petroleum hydrocarbons compared to traditional methods. Preliminary work using GCxGC has focused on examining the chemical composition of unrefined petroleum as it migrates up from depth through natural faults to the seafloor, from the seafloor to the sea surface, and from the sea surface to local beaches. Petroleum collected from a subsurface reservoir (Platform Holly Well 2342-15) is composed of a wide range of resolved petroleum hydrocarbons including n-alkanes, branched alkanes, cycloalkanes, linear alkane benzenes, polycyclic aromatic hydrocarbons, steranes, hopanes, cyclic isoprenoids, and very large branched biomarkers with 38 to 40 carbons. This product is significantly different than oil emerging from the seafloor at the Jackpot seep, which we believe is

  10. Comparison of computer-aided detection of clustered microcalcifications in digital mammography and digital breast tomosynthesis

    Science.gov (United States)

    Samala, Ravi K.; Chan, Heang-Ping; Lu, Yao; Hadjiiski, Lubomir; Wei, Jun; Helvie, Mark

    2015-03-01

    Digital breast tomosynthesis (DBT) has the potential to replace digital mammography (DM) for breast cancer screening. An effective computer-aided detection (CAD) system for microcalcification clusters (MCs) on DBT will facilitate the transition. In this study, we collected a data set with corresponding DBT and DM for the same breasts. DBT was acquired with IRB approval and informed consent using a GE GEN2 DBT prototype system. The DM acquired with a GE Essential system for the patient's clinical care was collected retrospectively from patient files. DM-based CAD (CADDM) and DBT-based CAD (CADDBT) were previously developed by our group. The major differences between the CAD systems include: (a) CADDBT uses two parallel processes whereas CADDM uses a single process for enhancing MCs and removing the structured background, (b) CADDBT has additional processing steps to reduce the false positives (FPs), including ranking of candidates of cluster seeds and cluster members and the use of adaptive CNR and size thresholds at clustering and FP reduction, (c) CADDM uses convolution neural network (CNN) and linear discriminant analysis (LDA) to differentiate true microcalcifications from FPs based on their morphological and CNN features. The performance difference is assessed by FROC analysis using test set (100 views with MCs and 74 views without MCs) independent of their respective training sets. At sensitivities of 70% and 80%, CADDBT achieved FP rates of 0.78 and 1.57 per view compared to 0.66 and 2.10 per image for the CADDM. JAFROC showed no significant difference between MC detection on DM and DBT by the two CAD systems.

  11. Comparison of Self Organizing Maps Clustering with Supervised Classification for Air Pollution Data Sets

    OpenAIRE

    Bougoudis, Ilias; Iliadis, Lazaros; Spartalis, Stephanos

    2014-01-01

    Part 10: Environmental AI; International audience; Air pollution is a serious problem of modern urban centers. The objective of this research is to investigate the problem by using Machine Learning techniques. It comprises of two parts. Firstly, it applies a well established Unsupervised Machine Learning approach (UML) namely Self Organizing Maps (SOM) for the clustering of Attica air quality big data vectors. This is done by using the concentrations of air pollutants (specific for each area)...

  12. Personality traits in patients with cluster headache: a comparison with migraine patients.

    Science.gov (United States)

    Muñoz, I; Hernández, M S; Santos, S; Jurado, C; Ruiz, L; Toribio, E; Sotelo, E M; Guerrero, A L; Molina, V; Uribe, F; Cuadrado, M L

    2016-01-01

    Cluster headache (CH) has been associated with certain personality traits and lifestyle features, but there are few studies assessing personality profiles in CH. We aimed to analyze personality traits in patients with CH, and to compare them with those found in migraine. We included all consecutive patients with CH attending 5 outpatient offices between January and December 2013. Personality traits were evaluated using the Salamanca screening test, a validated inventory assessing 11 personality traits grouped in 3 clusters. We analyzed the test results in this population, and compared them with those of a migraine population previously assessed with the same test. Eighty patients with CH (75 men, 5 women; mean age, 43.2 ± 9.9 years) were recruited. The reference population consisted of 164 migraine patients (30 men, 134 women; mean age 36.4 ± 12.7 years). In CH patients, the most frequent personality traits were anancastic (52.5 %), anxious (47.5 %), histrionic (45 %), schizoid (42.5 %), impulsive (32.5 %) and paranoid (30 %). When compared to migraine patients, paranoid (p personality traits included in cluster A (odd or eccentric disorders) are more prevalent in CH patients than in a population of migraineurs. Larger studies are needed to determine whether certain personality traits are related to CH.

  13. Comparison Analysis and Evaluation of Urban Competitiveness in Chinese Urban Clusters

    Directory of Open Access Journals (Sweden)

    Haixiang Guo

    2015-04-01

    Full Text Available With accelerating urbanization, urban competitiveness has become a worldwide academic focus. Previous studies always focused on economic factors but ignored social elements when measuring urban competitiveness. In this paper, a city was considered as a whole containing different units such as departments, individuals and economic activities, which interact with each other and affect its economic operation. Moreover, a city’s development was compared to an object’s movement, and the components were compared to different forces acting upon the object. With the analysis of the principle of object movement, this study has established a more scientific evaluation index system that involves 4 subsystems, 12 elements and 58 indexes. By using the TOPSIS method, the study has worked out the urban competitiveness of 141 cities from 28 Chinese urban clusters in 2009. According to the calculation results, these cities were divided into four levels: A, B, C, D. Furthermore, in order to analyze the competitiveness of cities and urban clusters, cities and urban clusters have been divided into four groups according to their distributive characteristics: the southeast, the northeast and Bohai Rim, the central region and the west. Suggestions and recommendations for each group are provided based on careful analysis.

  14. Comparison of illness representations dimensions and illness representation clusters in predicting outcomes in the first year following diagnosis of type 2 diabetes

    DEFF Research Database (Denmark)

    Skinner, T. C.; Carey, M. E.; Cradock, S.

    2011-01-01

    description of the data. The mean profiles of these clusters were comparable with groups identified by the independent qualitative analysis, and predicted the trajectory of illness outcomes over the 1-year follow-up. Combining illness beliefs into discrete clusters may be more useful in understanding patterns......This article explores the utility of cluster analysis of illness representations, in comparison to analysing each dimension of the individual's illness representation, to predict an individual's response to diagnosis of type 2 diabetes. Participants in a large multi-centre randomised controlled...... of the cluster analysis were compared with an independent qualitative study of participants' responses to diagnosis and participation in the study. The quantitative analysis of 564 participants for whom complete data were available, identified four clusters of illness representations as the most parsimonious...

  15. A Comparison of AOP Classification Based on Difficulty, Importance, and Frequency by Cluster Analysis and Standardized Mean

    International Nuclear Information System (INIS)

    Choi, Sun Yeong; Jung, Wondea

    2014-01-01

    In Korea, there are plants that have more than one-hundred kinds of abnormal operation procedures (AOPs). Therefore, operators have started to recognize the importance of classifying the AOPs. They should pay attention to those AOPs required to take emergency measures against an abnormal status that has a more serious effect on plant safety and/or often occurs. We suggested a measure of prioritizing AOPs for a training purpose based on difficulty, importance, and frequency. A DIF analysis based on how difficult the task is, how important it is, and how frequently they occur is a well-known method of assessing the performance, prioritizing training needs and planning. We used an SDIF-mean (Standardized DIF-mean) to prioritize AOPs in the previous paper. For the SDIF-mean, we standardized the three kinds of data respectively. The results of this research will be utilized not only to understand the AOP characteristics at a job analysis level but also to develop an effective AOP training program. The purpose of this paper is to perform a cluster analysis for an AOP classification and compare the results through a cluster analysis with that by a standardized mean based on difficulty, importance, and frequency. In this paper, we categorized AOPs into three groups by a cluster analysis based on D, I, and F. Clustering is the classification of similar objects into groups so that each group shares some common characteristics. In addition, we compared the result by the cluster analysis in this paper with the classification result by the SDIF-mean in the previous paper. From the comparison, we found that a reevaluation can be required to assign a training interval for the AOPs of group C' in the previous paper those have lower SDIF-mean. The reason for this is that some of the AOPs of group C' have quite high D and I values while they have the lowest frequencies. From an educational point of view, AOPs in group which have the highest difficulty and importance, but

  16. A comparison of methods for the analysis of binomial clustered outcomes in behavioral research.

    Science.gov (United States)

    Ferrari, Alberto; Comelli, Mario

    2016-12-01

    In behavioral research, data consisting of a per-subject proportion of "successes" and "failures" over a finite number of trials often arise. This clustered binary data are usually non-normally distributed, which can distort inference if the usual general linear model is applied and sample size is small. A number of more advanced methods is available, but they are often technically challenging and a comparative assessment of their performances in behavioral setups has not been performed. We studied the performances of some methods applicable to the analysis of proportions; namely linear regression, Poisson regression, beta-binomial regression and Generalized Linear Mixed Models (GLMMs). We report on a simulation study evaluating power and Type I error rate of these models in hypothetical scenarios met by behavioral researchers; plus, we describe results from the application of these methods on data from real experiments. Our results show that, while GLMMs are powerful instruments for the analysis of clustered binary outcomes, beta-binomial regression can outperform them in a range of scenarios. Linear regression gave results consistent with the nominal level of significance, but was overall less powerful. Poisson regression, instead, mostly led to anticonservative inference. GLMMs and beta-binomial regression are generally more powerful than linear regression; yet linear regression is robust to model misspecification in some conditions, whereas Poisson regression suffers heavily from violations of the assumptions when used to model proportion data. We conclude providing directions to behavioral scientists dealing with clustered binary data and small sample sizes. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Characteristic metabolism of free amino acids in cetacean plasma: cluster analysis and comparison with mice.

    Directory of Open Access Journals (Sweden)

    Kazuki Miyaji

    Full Text Available From an evolutionary perspective, the ancestors of cetaceans first lived in terrestrial environments prior to adapting to aquatic environments. Whereas anatomical and morphological adaptations to aquatic environments have been well studied, few studies have focused on physiological changes. We focused on plasma amino acid concentrations (aminograms since they show distinct patterns under various physiological conditions. Plasma and urine aminograms were obtained from bottlenose dolphins, pacific white-sided dolphins, Risso's dolphins, false-killer whales and C57BL/6J and ICR mice. Hierarchical cluster analyses were employed to uncover a multitude of amino acid relationships among different species, which can help us understand the complex interrelations comprising metabolic adaptations. The cetacean aminograms formed a cluster that was markedly distinguishable from the mouse cluster, indicating that cetaceans and terrestrial mammals have quite different metabolic machinery for amino acids. Levels of carnosine and 3-methylhistidine, both of which are antioxidants, were substantially higher in cetaceans. Urea was markedly elevated in cetaceans, whereas the level of urea cycle-related amino acids was lower. Because diving mammals must cope with high rates of reactive oxygen species generation due to alterations in apnea/reoxygenation and ischemia-reperfusion processes, high concentrations of antioxidative amino acids are advantageous. Moreover, shifting the set point of urea cycle may be an adaptation used for body water conservation in the hyperosmotic sea water environment, because urea functions as a major blood osmolyte. Furthermore, since dolphins are kept in many aquariums for observation, the evaluation of these aminograms may provide useful diagnostic indices for the assessment of cetacean health in artificial environments in the future.

  18. A new species of Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae) from Alectoris barbara (Aves: Phasianidae) from the Canary Islands (Spain)

    Czech Academy of Sciences Publication Activity Database

    Fernández-Alvarez, A.; Modrý, David; Foronda, P.

    2016-01-01

    Roč. 115, č. 5 (2016), s. 1817-1825 ISSN 0932-0113 Institutional support: RVO:60077344 Keywords : Coccidia * Eimeria barbarae n. sp * Alectoris barbara * Canary Island Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.329, year: 2016

  19. Cluster based on sequence comparison of homologous proteins of 95 organism species - Gclust Server | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available List Contact us Gclust Server Cluster based on sequence comparison of homologous proteins of 95 organism spe...cies Data detail Data name Cluster based on sequence comparison of homologous proteins of 95 organism specie...ta, and heuristic estimation of a similarity threshold for homologs of each protein by entropy-optimized organi...no acid sequences of predicted proteins and their annotation for 95 organism species . Data analysis method ...y threshold for homologs of each protein by entropy-optimized organism count method ( Bioinformatics 2009 Ma

  20. Submarine landslides in the Santa Barbara Channel as potential tsunami sources

    Directory of Open Access Journals (Sweden)

    H. G. Greene

    2006-01-01

    Full Text Available Recent investigations using the Monterey Bay Aquarium Research Institutes (MBARI Remotely Operated Vehicles (ROVs 'Ventana' and 'Tiburon' and interpretation of MBARI's EM 300 30 kHz multibeam bathymetric data show that the northern flank of the Santa Barbara Basin has experienced massive slope failures. Of particular concern is the large (130 km2 Goleta landslide complex located off Coal Oil Point near the town of Goleta, that measures 14.6-km long extending from a depth of 90 m to nearly 574 m deep and is 10.5 km wide. We estimate that approximately 1.75 km3 has been displaced by this slide during the Holocene. This feature is a complex compound submarine landslide that contains both surfical slump blocks and mud flows in three distinct segments. Each segment is composed of a distinct head scarp, down-dropped head block and a slide debris lobe. The debris lobes exhibit hummocky topography in the central areas that appear to result from compression during down slope movement. The toes of the western and eastern lobes are well defined in the multibeam image, whereas the toe of the central lobe is less distinct. Continuous seismic reflection profiles show that many buried slide debris lobes exist and comparison of the deformed reflectors with ODP Drill Site 149, Hole 893 suggest that at least 200 000 years of failure have occurred in the area (Fisher et al., 2005a. Based on our interpretation of the multibeam bathymetry and seismic reflection profiles we modeled the potential tsunami that may have been produced from one of the three surfical lobes of the Goleta slide. This model shows that a 10 m high wave could have run ashore along the cliffs of the Goleta shoreline. Several other smaller (2 km2 and 4 km2 slides are located on the northern flank of the Santa Barbara Basin, both to the west and east of Goleta slide and on the Conception fan along the western flank of the basin. One slide, named the Gaviota slide, is 3.8 km2, 2.6 km long and 1

  1. Comparison of combinatorial clustering methods on pharmacological data sets represented by machine learning-selected real molecular descriptors.

    Science.gov (United States)

    Rivera-Borroto, Oscar Miguel; Marrero-Ponce, Yovani; García-de la Vega, José Manuel; Grau-Ábalo, Ricardo del Corazón

    2011-12-27

    Cluster algorithms play an important role in diversity related tasks of modern chemoinformatics, with the widest applications being in pharmaceutical industry drug discovery programs. The performance of these grouping strategies depends on various factors such as molecular representation, mathematical method, algorithmical technique, and statistical distribution of data. For this reason, introduction and comparison of new methods are necessary in order to find the model that best fits the problem at hand. Earlier comparative studies report on Ward's algorithm using fingerprints for molecular description as generally superior in this field. However, problems still remain, i.e., other types of numerical descriptions have been little exploited, current descriptors selection strategy is trial and error-driven, and no previous comparative studies considering a broader domain of the combinatorial methods in grouping chemoinformatic data sets have been conducted. In this work, a comparison between combinatorial methods is performed,with five of them being novel in cheminformatics. The experiments are carried out using eight data sets that are well established and validated in the medical chemistry literature. Each drug data set was represented by real molecular descriptors selected by machine learning techniques, which are consistent with the neighborhood principle. Statistical analysis of the results demonstrates that pharmacological activities of the eight data sets can be modeled with a few of families with 2D and 3D molecular descriptors, avoiding classification problems associated with the presence of nonrelevant features. Three out of five of the proposed cluster algorithms show superior performance over most classical algorithms and are similar (or slightly superior in the most optimistic sense) to Ward's algorithm. The usefulness of these algorithms is also assessed in a comparative experiment to potent QSAR and machine learning classifiers, where they perform

  2. Optimal clustering of kinetic patterns on malignant breast lesions: comparison between K-means clustering and three-time-points method in dynamic contrast-enhanced MRI.

    Science.gov (United States)

    Lee, S H; Kim, J H; Kim, K G; Park, J S; Park, S J; Moon, W K

    2007-01-01

    Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is useful for breast cancer diagnosis and treatment planning. Nevertheless, due to the multi-temporal nature of DCE-MRI data, the assessment of early stage breast cancer is a challenging task. In this study, we applied an unsupervised clustering approach and cluster validation technique to the analysis of malignant intral-tumoral kinetic curves in DCE-MRI. K-means cluster analysis was performed from real world malignant tumor cases and the data were transformed into an optimal number of reference patterns representative each cluster. The optimal number of clusters was estimated by a cluster validation index, which was calculated with the ratio of inter-class scatter to intra-class scatter. This technique then classifies tumor specific patterns from a given MRI data by measuring the vector distances from the reference pattern set, and compared the result from the k-means clustering with that from three-time-points (3TP) method, which represents a clinical standard protocol for analysis of tumor kinetics. The evaluation of twenty five cases indicates that optimal k-means clustering reflects partitioning intra-tumoral kinetic patterns better than the 3TP technique. This method will greatly enhance the capability of radiologists to identify and characterize internal kinetic heterogeneity and vascular change of a tumor in breast DCE-MRI.

  3. Comparison of detection efficiencies of negatively charged gold-alkanethiolate-, gold-sulfur- and gold-clusters in ToF-SIMS

    International Nuclear Information System (INIS)

    Rietmann, T.; Sohn, S.; Schroeder, M.; Lipinsky, D.; Arlinghaus, H.F.

    2006-01-01

    In order to improve quantification of high mass ions, the influence of cluster composition on detection efficiencies has been studied using a TOF-SIMS IV with the extended capability of postaccelerating ions up to 20 keV. In this experimental study, we focus on the comparison of detection efficiencies for three types of negatively charged secondary cluster ions: gold-alkanethiolate-clusters (Au x M y ), gold-sulfur-clusters (Au x S y ) and gold-clusters (Au x ). The clusters were sputtered from self-assembled monolayers of hexadecanethiols on gold substrates using 10 keV Ar + primary ions. The detection efficiencies were derived on the basis of a function for the secondary electron yield and a fourth-order approximated Poisson probability distribution for electron propagation and amplification within the microchannel plate. In addition to the well-known dependence of detection efficiencies on ion mass and energy, which has already been studied for positively charged ions, we were able to show a similar behaviour for the investigated negatively charged secondary ions. We have observed major variations among the three types of clusters at similar mass and energy as predicted in a theoretical approach. The observed differences are due to the different composition of the investigated clusters which has a major influence on the kinetic ion induced electron emission within the microchannel plate. For the first time it was possible to experimentally verify these predictions for detection efficiencies

  4. Comparison of owner-reported behavioral characteristics among genetically clustered breeds of dog (Canis familiaris).

    Science.gov (United States)

    Tonoike, Akiko; Nagasawa, Miho; Mogi, Kazutaka; Serpell, James A; Ohtsuki, Hisashi; Kikusui, Takefumi

    2015-12-18

    During the domestication process, dogs were selected for their suitability for multiple purposes, resulting in a variety of behavioral characteristics. In particular, the ancient group of breeds that is genetically closer to wolves may show different behavioral characteristics when compared to other breed groups. Here, we used questionnaire evaluations of dog behavior to investigate whether behavioral characteristics of dogs were different among genetically clustered breed groups. A standardized questionnaire, the Canine Behavioral Assessment and Research Questionnaire (C-BARQ), was used, and breed group differences of privately-owned dogs from Japan (n = 2,951) and the United States (n = 10,389) were analyzed. Results indicated that dogs in the ancient and spitz breed group showed low attachment and attention-seeking behavior. This characteristic distinguished the ancient group from any other breed groups with presumed modern European origins, and may therefore, be an ancestral trait.

  5. Intensive Cultural Resources Survey for the Goleta Flood Protection Program, Santa Barbara County, California.

    Science.gov (United States)

    1982-04-01

    years old or greater, " adultos ". The percentage of people eventually baptized from the Goleta towns who were living in 1782 was 56.5%, if the midpoint... Mayor of Santa Barbara called the Slough "One of the area’s greatest economic assets, given its tourist potential, if properly developed (SBNP April

  6. Blue oak plant communities of southern San Luis Obispo and northern Santa Barbara Counties, California

    Science.gov (United States)

    Mark I. Borchert; Nancy D. Cunha; Patricia C. Krosse; Marcee L. Lawrence

    1993-01-01

    An ecological classification system has been developed for the Pacific Southwest Region of the Forest Service. As part of that classification effort, blue oak (Quercus douglasii) woodlands and forests of southern San Luis Obispo and northern Santa Barbara Counties in Los Padres National Forest were classified into I3 plant communities using...

  7. 76 FR 5319 - Revisions to the California State Implementation Plan, Santa Barbara Air Pollution Control...

    Science.gov (United States)

    2011-01-31

    ... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Santa Barbara Air Pollution Control District, Placer County Air Pollution Control District, Antelope Valley Air Quality Management District, and Ventura County Air Pollution Control District AGENCY: Environmental Protection Agency (EPA...

  8. 77 FR 34991 - Notice of Inventory Completion: University of California, Santa Barbara, Repository of...

    Science.gov (United States)

    2012-06-12

    ... permission of the private land owner, as part of W. Harrison's doctorate dissertation research at the... Barbara County, CA, by W. Harrison and P. Lyons, as part of Harrison's doctorate dissertation research... joint UCSB and University of California, Los Angeles, summer field school, directed by Claude Warren...

  9. Christian Petzold’s melodramas : From unknown woman to reciprocal unknownness in Phoenix, Wolfsburg, and Barbara

    NARCIS (Netherlands)

    Staat, W.

    2016-01-01

    Stanley Cavell’s theory of film melodrama is used for Christian Petzold’s Phoenix, Wolfsburg, and Barbara. Key for Cavell’s understanding of classical Hollywood melodrama is his notion of the ‘unknown woman.’ Remarkably, Petzold’s more contemporary melodramas feature unknown, i.e. unacknowledged,

  10. Comparison of population-averaged and cluster-specific models for the analysis of cluster randomized trials with missing binary outcomes: a simulation study

    Directory of Open Access Journals (Sweden)

    Ma Jinhui

    2013-01-01

    Full Text Available Abstracts Background The objective of this simulation study is to compare the accuracy and efficiency of population-averaged (i.e. generalized estimating equations (GEE and cluster-specific (i.e. random-effects logistic regression (RELR models for analyzing data from cluster randomized trials (CRTs with missing binary responses. Methods In this simulation study, clustered responses were generated from a beta-binomial distribution. The number of clusters per trial arm, the number of subjects per cluster, intra-cluster correlation coefficient, and the percentage of missing data were allowed to vary. Under the assumption of covariate dependent missingness, missing outcomes were handled by complete case analysis, standard multiple imputation (MI and within-cluster MI strategies. Data were analyzed using GEE and RELR. Performance of the methods was assessed using standardized bias, empirical standard error, root mean squared error (RMSE, and coverage probability. Results GEE performs well on all four measures — provided the downward bias of the standard error (when the number of clusters per arm is small is adjusted appropriately — under the following scenarios: complete case analysis for CRTs with a small amount of missing data; standard MI for CRTs with variance inflation factor (VIF 50. RELR performs well only when a small amount of data was missing, and complete case analysis was applied. Conclusion GEE performs well as long as appropriate missing data strategies are adopted based on the design of CRTs and the percentage of missing data. In contrast, RELR does not perform well when either standard or within-cluster MI strategy is applied prior to the analysis.

  11. Comparison of media literacy and usual education to prevent tobacco use: a cluster randomized trial

    Science.gov (United States)

    Douglas, Erika L.; Land, Stephanie R.; Miller, Elizabeth; Fine, Michael J.

    2014-01-01

    BACKGROUND Media literacy programs have shown potential for reduction of adolescent tobacco use. We aimed to determine if an anti-smoking media literacy curriculum improves students’ media literacy and affects factors related to adolescent smoking. METHODS We recruited 1170 9th grade students from 64 classrooms in 3 public urban high schools. Students were randomized by classroom to a media literacy curriculum versus a standard educational program. In an intent-to-treat analysis, we used multi-level modeling to determine if changes in study outcomes were associated with the curricular intervention, controlling for baseline student covariates and the clustering of students within classrooms. RESULTS Among participants, mean age was 14.5 years and 51% were male, with no significant differences in baseline characteristics between groups. Smoking media literacy changed more among intervention participants compared with control participants (0.24 vs. 0.08, p media literacy curriculum is more effective than a standard educational program in teaching media literacy and improving perceptions of the true prevalence of smoking among adolescents. PMID:25099425

  12. Comparison of Degrees of Potential-Energy-Surface Anharmonicity for Complexes and Clusters with Hydrogen Bonds

    Science.gov (United States)

    Kozlovskaya, E. N.; Doroshenko, I. Yu.; Pogorelov, V. E.; Vaskivskyi, Ye. V.; Pitsevich, G. A.

    2018-01-01

    Previously calculated multidimensional potential-energy surfaces of the MeOH monomer and dimer, water dimer, malonaldehyde, formic acid dimer, free pyridine-N-oxide/trichloroacetic acid complex, and protonated water dimer were analyzed. The corresponding harmonic potential-energy surfaces near the global minima were constructed for series of clusters and complexes with hydrogen bonds of different strengths based on the behavior of the calculated multidimensional potential-energy surfaces. This enabled the introduction of an obvious anharmonicity parameter for the calculated potential-energy surfaces. The anharmonicity parameter was analyzed as functions of the size of the analyzed area near the energy minimum, the number of points over which energies were compared, and the dimensionality of the solved vibrational problem. Anharmonicity parameters for potential-energy surfaces in complexes with strong, medium, and weak H-bonds were calculated under identical conditions. The obtained anharmonicity parameters were compared with the corresponding diagonal anharmonicity constants for stretching vibrations of the bridging protons and the lengths of the hydrogen bridges.

  13. Comparison of Three Plot Selection Methods for Estimating Change in Temporally Variable, Spatially Clustered Populations.

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, William L. [Bonneville Power Administration, Portland, OR (US). Environment, Fish and Wildlife

    2001-07-01

    Monitoring population numbers is important for assessing trends and meeting various legislative mandates. However, sampling across time introduces a temporal aspect to survey design in addition to the spatial one. For instance, a sample that is initially representative may lose this attribute if there is a shift in numbers and/or spatial distribution in the underlying population that is not reflected in later sampled plots. Plot selection methods that account for this temporal variability will produce the best trend estimates. Consequently, I used simulation to compare bias and relative precision of estimates of population change among stratified and unstratified sampling designs based on permanent, temporary, and partial replacement plots under varying levels of spatial clustering, density, and temporal shifting of populations. Permanent plots produced more precise estimates of change than temporary plots across all factors. Further, permanent plots performed better than partial replacement plots except for high density (5 and 10 individuals per plot) and 25% - 50% shifts in the population. Stratified designs always produced less precise estimates of population change for all three plot selection methods, and often produced biased change estimates and greatly inflated variance estimates under sampling with partial replacement. Hence, stratification that remains fixed across time should be avoided when monitoring populations that are likely to exhibit large changes in numbers and/or spatial distribution during the study period. Key words: bias; change estimation; monitoring; permanent plots; relative precision; sampling with partial replacement; temporary plots.

  14. Comparison of the applicability of neural networks and cluster classification methods on the example company's financial situation

    Directory of Open Access Journals (Sweden)

    Oldřich Trenz

    2010-01-01

    Full Text Available The paper is focused on comparing the classification ability of the model with self-learning neutral network and methods from cluster analysis. The emphasis is particularly on the comparison of different approaches to a specific application example of the commitment, the classification of then financial situation. The aim is to critically evaluate different approaches at the level of application and deployment options.The verify the classification capability of the different approaches were used financial data from the database „Credit Info“, in particular data describing the financial situation of the two hundred eleven farms of homogeneous and uniform primary field.Input data were from the methods used, modified and evaluated by appropriate methodology. Found the final solution showed that the used approaches do not show significant differences, and they can say that they are equivalent. Based on this finding can formulate the conclusion that the approach of artificial intelligence (self-learning neural network is as effective as a partial methods in the field of cluster analysis. In both cases, these approaches can be an invaluable tool in decision making.When the financial situation is evaluated by the expert, the calculation of liquidity, profitability and other financial indicators are making some simplification. In this respect, neural networks perform better, since these simplifications in them selves are not natively included. They can better assess and somewhat ambiguous cases, including businesses with undefined financial situation, the so-called data in the border region. In this respect, support and representation of the graphical layout of the resulting situation sorted out objects using software implemented neural network model.

  15. Unusual reactivity of dithiol protected clusters in comparison to monothiol protected clusters: studies using Ag51(BDT)19(TPP)3and Ag29(BDT)12(TPP)4.

    Science.gov (United States)

    Ghosh, Atanu; Ghosh, Debasmita; Khatun, Esma; Chakraborty, Papri; Pradeep, Thalappil

    2017-01-19

    We report the synthesis and unique reactivity of a new green dithiol protected cluster (DTPC), Ag 51 (BDT) 19 (TPP) 3 (BDT and TPP are 1,3-benzenedithiol and triphenylphosphine, respectively). The cluster composition was confirmed by electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) mass spectrometric studies as well as by other supporting data. Surprisingly, the chemical reactivity between this DTPC and Au 25 (SR) 18 involves only metal ion exchange in Au 25 (SR) 18 without any ligand exchange, while reactions between monothiol protected clusters (MTPCs) show both metal and ligand exchange, an example being the reaction between Ag 25 DMBT 18 and Au 25 PET 18 (where DMBT and PET are 2,4-dimethylbenzenethiol and phenylethanethiol, respectively). The conclusions have been confirmed by the reaction of another DTPC, Ag 29 (BDT) 12 (TPP) 4 with Au 25 BT 18 (where BT corresponds to butanethiol) in which only metal exchange happens in Au 25 BT 18 . We also show the conversion of Ag 51 (BDT) 19 (TPP) 3 to Ag 29 (BDT) 12 (TPP) 4 in the presence of a second monothiol, DMBT which does not get integrated into the product cluster. This is completely different from the previous understanding wherein the reaction between MTPCs and a second thiol leads to either mixed thiol protected clusters with the same core composition or a completely new cluster core protected with the second thiol. The present study exposes a new avenue of research for monolayer protected clusters, which in turn will give additional impetus to explore the chemistry of DTPCs.

  16. Hatching phenology and voltinism of Heterocypris barbara (Crustacea: Ostracoda from Lampedusa (Sicily, Italy

    Directory of Open Access Journals (Sweden)

    Valeria Rossi

    2013-04-01

    Full Text Available The persistence of crustacean populations in ephemeral ponds requires appropriate adaptations in life history strategies (e.g. in hatching phenology. Organisms take advantage of pond filling when it occurs and hedge their bets for the possibility to complete one or more life cycles or to produce resting stages that ensure that the population will not go extinct. We carried out laboratory experiments to investigate the dynamics of a sexual population of Heterocypris barbara from a vernal pool in Lampedusa Island (Sicily. Experimental organisms were obtained hydrating sediments from Aria Rossa temporary pond. Recruitment from resting eggs, voltinism, mean body size and sex ratio were observed in microcosms at different conductivities (high 2.0-2.7 mS cm-1, intermediate 1.0-1.1 mS cm-1 and low 0.5-0.6 mS cm-1. Microcosms were kept in laboratory controlled conditions: constant (24°C 12:12 L:D and 16°C 10:14 L:D photoperiod or fluctuating thermal regimes. The experiment lasted 7 months. Resting and non-resting egg production and up to a bivoltine life cycle were observed. Recruitment events from egg bank and voltinism varied by thermal regime and conductivity. A prolonged recruitment phase occurred in conditions that could be considered a proxy of a rainy season (16°C, 10:14 L:D and low conductivity or of long hydroperiods (spring thermal fluctuating regime and intermediate conductivity. At 24°C, age at reproduction of females from resting eggs almost doubled at low conductivity (in comparison with high conductivity. Low conductivity also reduced hatching time of resting eggs while it increased development time and age at maturity. In thermal fluctuating regime, degree-days to reproduction were about double than at constant 24°C. Males, observed in all microcosms, reached maturity faster and had a shorter life span than females. Males initially outnumbered females, but later in the experiments females became dominant. We also evaluated the

  17. Non-stationarity of the quasi-perpendicular bow shock: comparison between Cluster observations and simulations

    Directory of Open Access Journals (Sweden)

    H. Comişel

    2011-02-01

    Full Text Available We have performed full particle electromagnetic simulations of a quasi-perpendicular shock. The shock parameters have been chosen to be appropriate for the quasi-perpendicular Earth's bow shock observed by Cluster on 24 January 2001 (Lobzin et al., 2007. We have performed two simulations with different ion to electron mass ratio: run 1 with mi/me=1840 and run 2 with mi/me=100. In run 1 the growth rate of the modified two-stream instability (MTSI is large enough to get excited during the reflection and upstream gyration of part of the incident solar wind ions. The waves due to the MTSI are on the whistler mode branch and have downstream directed phase velocities in the shock frame. The Poynting flux (and wave group velocity far upstream in the foot is also directed in the downstream direction. However, in the density and magnetic field compression region of the overshoot the waves are refracted and the Poynting flux in the shock frame is directed upstream. The MTSI is suppressed in the low mass ratio run 2. The low mass ratio run shows more clearly the non-stationarity of the shock with a larger time scale of the order of an inverse ion gyrofrequency (Ωci: the magnetic field profile flattens and steepens with a period of ~1.5Ωci−1. This non-stationarity is different from reformation seen in previous simulations of perpendicular or quasi-perpendicular shocks. Beginning with a sharp shock ramp the large electric field in the normal direction leads to high reflection rate of solar wind protons. As they propagate upstream, the ion bulk velocity decreases and the magnetic field increases in the foot, which results in a flattening of the magnetic field profile and in a decrease of the normal electric field. Subsequently the reflection rate decreases and the whole shock profile steepens again. Superimposed on this 'breathing' behavior are in the realistic mass ratio case the waves due to the MTSI. The simulations lead us to a re-interpretation of

  18. A Study of the Classification Capabilities of Neural Networks Using Unsupervised Learning: A Comparison with K-Means Clustering.

    Science.gov (United States)

    Balakrishnan, P. V. (Sunder); And Others

    1994-01-01

    A simulation study compares nonhierarchical clustering capabilities of a class of neural networks using Kohonen learning with a K-means clustering procedure. The focus is on the ability of the procedures to recover correctly the known cluster structure in the data. Advantages and disadvantages of the procedures are reviewed. (SLD)

  19. Insight into acid-base nucleation experiments by comparison of the chemical composition of positive, negative, and neutral clusters.

    Science.gov (United States)

    Bianchi, Federico; Praplan, Arnaud P; Sarnela, Nina; Dommen, Josef; Kürten, Andreas; Ortega, Ismael K; Schobesberger, Siegfried; Junninen, Heikki; Simon, Mario; Tröstl, Jasmin; Jokinen, Tuija; Sipilä, Mikko; Adamov, Alexey; Amorim, Antonio; Almeida, Joao; Breitenlechner, Martin; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Kangasluoma, Juha; Keskinen, Helmi; Kim, Jaeseok; Kirkby, Jasper; Laaksonen, Ari; Lawler, Michael J; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Riccobono, Francesco; Rissanen, Matti P; Rondo, Linda; Tomé, António; Virtanen, Annele; Viisanen, Yrjö; Williamson, Christina; Wimmer, Daniela; Winkler, Paul M; Ye, Penglin; Curtius, Joachim; Kulmala, Markku; Worsnop, Douglas R; Donahue, Neil M; Baltensperger, Urs

    2014-12-02

    We investigated the nucleation of sulfuric acid together with two bases (ammonia and dimethylamine), at the CLOUD chamber at CERN. The chemical composition of positive, negative, and neutral clusters was studied using three Atmospheric Pressure interface-Time Of Flight (APi-TOF) mass spectrometers: two were operated in positive and negative mode to detect the chamber ions, while the third was equipped with a nitrate ion chemical ionization source allowing detection of neutral clusters. Taking into account the possible fragmentation that can happen during the charging of the ions or within the first stage of the mass spectrometer, the cluster formation proceeded via essentially one-to-one acid-base addition for all of the clusters, independent of the type of the base. For the positive clusters, the charge is carried by one excess protonated base, while for the negative clusters it is carried by a deprotonated acid; the same is true for the neutral clusters after these have been ionized. During the experiments involving sulfuric acid and dimethylamine, it was possible to study the appearance time for all the clusters (positive, negative, and neutral). It appeared that, after the formation of the clusters containing three molecules of sulfuric acid, the clusters grow at a similar speed, independent of their charge. The growth rate is then probably limited by the arrival rate of sulfuric acid or cluster-cluster collision.

  20. Basin-scale wind transport during the MILAGRO field campaign and comparison to climatology using cluster analysis

    Directory of Open Access Journals (Sweden)

    B. de Foy

    2008-03-01

    Full Text Available The MILAGRO field campaign was a multi-agency international collaborative project to evaluate the regional impacts of the Mexico City air pollution plume as a means of understanding urban impacts on the global climate. Mexico City lies on an elevated plateau with mountains on three sides and has complex mountain and surface-driven wind flows. This paper asks what the wind transport was in the basin during the field campaign and how representative it was of the climatology. Surface meteorology and air quality data, radiosondes and radar wind profiler data were collected at sites in the basin and its vicinity. Cluster analysis was used to identify the dominant wind patterns both during the campaign and within the past 10 years of operational data from the warm dry season. Our analysis shows that March 2006 was representative of typical flow patterns experienced in the basin. Six episode types were identified for the basin-scale circulation providing a way of interpreting atmospheric chemistry and particulate data collected during the campaign. Decoupling between surface winds and those aloft had a strong influence in leading to convection and poor air quality episodes. Hourly characterisation of wind circulation during the MILAGRO, MCMA-2003 and IMADA field campaigns enables the comparisons of similar air pollution episodes and the evaluation of the impact of wind transport on measurements of the atmospheric chemistry taking place in the basin.

  1. Reviews by Barbara Santini, Andrea Mecacci, Mariagrazia Portera, Francesca Zugno, and Alberto Ricci

    Directory of Open Access Journals (Sweden)

    Fausto Cercignani

    2014-06-01

    Full Text Available Review of Daniele Goldoni’s book Gratitudine. Voci di Hölderlin (2013, by Barbara Santini. Review of Laura Anna Macor’s book La fragilità delle virtù. Dall’antropologia alla morale e ritorno nell’epoca di Kant (2011, by Andrea Mecacci. Review of the collection of essays Friedrich Hölderlin. Pensiero e poesia, ed. by Elena Polledri (special volume of the journal «Humanitas», 2012, by Mariagrazia Portera. Review of Barbara Santini’s book Soggetto e fondamento in Hölderlin tra filosofia trascendentale e pensiero speculativo (2013, by Francesca Zugno. Review of Francesca Zugno’s book Hölderlin oltre Kant. Verso Hyperion. 1794-1797 (2011, by Alberto Ricci.

  2. Christa McAuliffe and Barbara Morgan train with Airiflex camera

    Science.gov (United States)

    1985-01-01

    Two women in training at JSC as part of the Teacher-in-Space Project and a position on NASA's STS 51-L mission learn handling of the Airiflex motion picture camera used on Shuttle flights. Sharon Christa McAuliffe (left) was named as prime crewmember for the 51-L flight; and Barbara R. Morgan, here lending help with camera's lens, will serve as backup.

  3. Rapports 2017-2018 sur les frais de voyage pour Barbara Lucille ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Billet d'avion. 436.15 $. Frais de transport au sol ou autrement. 98.00 $. Frais de logement. 361.85 $. Repas et frais divers. 219.51 $. Autre frais. 0.00 $. Total. 1 115.51 $. Commentaires. À partir de sa résidence à Fredericton, NB. Rapports 2017-2018 sur les frais de voyage pour. Barbara Lucille Trenholm, gouverneur, ...

  4. 33 CFR 167.452 - In the Santa Barbara Channel: Between Point Conception and Point Arguello.

    Science.gov (United States)

    2010-07-01

    ....452 In the Santa Barbara Channel: Between Point Conception and Point Arguello. (a) A separation zone... 120°30.16′ W. 34°18.90′ N 120°30.96′ W. 34°25.70′ N 120°51.81′ W. 34°23.75′ N 120°52.51′ W. (b) A traffic lane for westbound traffic is established between the separation zone and a line connecting the...

  5. Mineralogical characterization of the argillaceous material from the Municipality of Santa Barbara, Para, Brazil

    International Nuclear Information System (INIS)

    Hildebrando, E.A.; Sheller, T.; Angelica, R.S.; Neves, R.S.

    2009-01-01

    In the present work were investigated mineralogical phases in a material with argillaceous characteristic of the region of Genipauba, Santa Barbara, State of Para. Characterization of the collected sample was performed by X-ray diffraction (XRD), differential thermal analysis (DTA), thermogravimetric analysis (TG) and infrared spectroscopy (IR). The results of the assays indicate the presence of the clay minerals like kaolinite and muscovite, as well as minerals as quartz and anatase. (author)

  6. LoCuSS: A COMPARISON OF SUNYAEV-ZEL'DOVICH EFFECT AND GRAVITATIONAL-LENSING MEASUREMENTS OF GALAXY CLUSTERS

    International Nuclear Information System (INIS)

    Marrone, Daniel P.; Culverhouse, Thomas; Carlstrom, John E.; Greer, Christopher; Hennessy, Ryan; Leitch, Erik M.; Loh, Michael; Pryke, Clem; Smith, Graham P.; Hamilton-Morris, Victoria; Richard, Johan; Joy, Marshall; Bonamente, Massimiliano; Hasler, Nicole; Kneib, Jean-Paul; Hawkins, David; Lamb, James W.; Muchovej, Stephen; Miller, Amber; Mroczkowski, Tony

    2009-01-01

    We present the first measurement of the relationship between the Sunyaev-Zel'dovich effect (SZE) signal and the mass of galaxy clusters that uses gravitational lensing to measure cluster mass, based on 14 X-ray luminous clusters at z ≅ 0.2 from the Local Cluster Substructure Survey. We measure the integrated Compton y-parameter, Y, and total projected mass of the clusters (M GL ) within a projected clustercentric radius of 350 kpc, corresponding to mean overdensities of 4000-8000 relative to the critical density. We find self-similar scaling between M GL and Y, with a scatter in mass at fixed Y of 32%. This scatter exceeds that predicted from numerical cluster simulations, however, it is smaller than comparable measurements of the scatter in mass at fixed T X . We also find no evidence of segregation in Y between disturbed and undisturbed clusters, as had been seen with T X on the same physical scales. We compare our scaling relation to the Bonamente et al. relation based on mass measurements that assume hydrostatic equilibrium, finding no evidence for a hydrostatic mass bias in cluster cores (M GL = 0.98 ± 0.13 M HSE ), consistent with both predictions from numerical simulations and lensing/X-ray-based measurements of mass-observable scaling relations at larger radii. Overall our results suggest that the SZE may be less sensitive than X-ray observations to the details of cluster physics in cluster cores.

  7. Theoretical studies on carbon and silicon clusters: Comparison of the structures and stabilities of neutral and ionic forms

    International Nuclear Information System (INIS)

    Raghavachari, K.

    1989-01-01

    Optimized molecular geometries and electronic structures are determined for neutral, positively charged, and negatively charged carbon and silicon clusters containing up to ten atoms. The effects of polarization functions and electron correlation are included in these calculations. Carbon clusters have linear or monocyclic ground state geometries whereas silicon clusters containing five or more atoms have three-dimensional ground state structures. Neutral C 4 , C 6 and C 8 all have linear and monocyclic isomers of comparable stability whereas the ionic forms appear to be generally more stable as linear geometrical arrangements. In the case of neutral and positively charged carbon clusters, the odd-numbered clusters are significantly more stable than the adjacent even-numbered clusters whereas the opposite order of stability occurs for the negative ions. This is due to the large values of the electron affinities of the linear forms of even-numbered clusters such as C 4 and C 6 . The relative stabilities of silicon clusters do not change with the charge state of the clusters. (orig.)

  8. Charged FeCn clusters: A comparison with TMCn+/TMCn- (TM = Sc, Ti, V, Co and Zn, n = 1-8) systems

    International Nuclear Information System (INIS)

    Redondo, Pilar; Largo, Laura; Barrientos, Carmen

    2009-01-01

    The electronic and geometrical structures of the ground and excited states for the linear, fan and cyclic isomers of FeC n + andFeC n - (n = 1-8) compounds are calculated using the B3LYP method. A comparison of these results with the previously obtained for TMC n + /TMC n - (TM = Sc, Ti, V, Co and Zn) systems, is carried out. Quartet and sextet states are found the most stables for FeC n + clusters. Linear FeC n - clusters prefer doublet and quartet ground states, whereas for cyclic and fan isomers the most stables are quartet and sextet ones. n-odd linear, fan, and cyclic FeC n + isomers are more stable than adjacent n-even ones. For FeC n - clusters the opposite trend is found for linear and fan structures, whereas for cyclic isomers the relative stability decreases along the series. In general linear isomers are the most stable conformations for FeC n + /FeC n - clusters. Systematic trends of different properties are analyzed for TMC n + /TMC n - clusters.

  9. Estimating multilevel logistic regression models when the number of clusters is low: a comparison of different statistical software procedures.

    Science.gov (United States)

    Austin, Peter C

    2010-04-22

    Multilevel logistic regression models are increasingly being used to analyze clustered data in medical, public health, epidemiological, and educational research. Procedures for estimating the parameters of such models are available in many statistical software packages. There is currently little evidence on the minimum number of clusters necessary to reliably fit multilevel regression models. We conducted a Monte Carlo study to compare the performance of different statistical software procedures for estimating multilevel logistic regression models when the number of clusters was low. We examined procedures available in BUGS, HLM, R, SAS, and Stata. We found that there were qualitative differences in the performance of different software procedures for estimating multilevel logistic models when the number of clusters was low. Among the likelihood-based procedures, estimation methods based on adaptive Gauss-Hermite approximations to the likelihood (glmer in R and xtlogit in Stata) or adaptive Gaussian quadrature (Proc NLMIXED in SAS) tended to have superior performance for estimating variance components when the number of clusters was small, compared to software procedures based on penalized quasi-likelihood. However, only Bayesian estimation with BUGS allowed for accurate estimation of variance components when there were fewer than 10 clusters. For all statistical software procedures, estimation of variance components tended to be poor when there were only five subjects per cluster, regardless of the number of clusters.

  10. Clustering Educational Digital Library Usage Data: A Comparison of Latent Class Analysis and K-Means Algorithms

    Science.gov (United States)

    Xu, Beijie; Recker, Mimi; Qi, Xiaojun; Flann, Nicholas; Ye, Lei

    2013-01-01

    This article examines clustering as an educational data mining method. In particular, two clustering algorithms, the widely used K-means and the model-based Latent Class Analysis, are compared, using usage data from an educational digital library service, the Instructional Architect (IA.usu.edu). Using a multi-faceted approach and multiple data…

  11. Predictive coupled-cluster isomer orderings for some SinCm (m, n ≤ 12) clusters: A pragmatic comparison between DFT and complete basis limit coupled-cluster benchmarks

    International Nuclear Information System (INIS)

    Byrd, Jason N.; Lutz, Jesse J.; Jin, Yifan; Ranasinghe, Duminda S.; Perera, Ajith; Bartlett, Rodney J.; Montgomery, John A.; Duan, Xiaofeng F.; Burggraf, Larry W.; Sanders, Beverly A.

    2016-01-01

    The accurate determination of the preferred Si 12 C 12 isomer is important to guide experimental efforts directed towards synthesizing SiC nano-wires and related polymer structures which are anticipated to be highly efficient exciton materials for the opto-electronic devices. In order to definitively identify preferred isomeric structures for silicon carbon nano-clusters, highly accurate geometries, energies, and harmonic zero point energies have been computed using coupled-cluster theory with systematic extrapolation to the complete basis limit for set of silicon carbon clusters ranging in size from SiC 3 to Si 12 C 12 . It is found that post-MBPT(2) correlation energy plays a significant role in obtaining converged relative isomer energies, suggesting that predictions using low rung density functional methods will not have adequate accuracy. Utilizing the best composite coupled-cluster energy that is still computationally feasible, entailing a 3-4 SCF and coupled-cluster theory with singles and doubles extrapolation with triple-ζ (T) correlation, the closo Si 12 C 12 isomer is identified to be the preferred isomer in the support of previous calculations [X. F. Duan and L. W. Burggraf, J. Chem. Phys. 142, 034303 (2015)]. Additionally we have investigated more pragmatic approaches to obtaining accurate silicon carbide isomer energies, including the use of frozen natural orbital coupled-cluster theory and several rungs of standard and double-hybrid density functional theory. Frozen natural orbitals as a way to compute post-MBPT(2) correlation energy are found to be an excellent balance between efficiency and accuracy.

  12. Comparison of loline alkaloid gene clusters across fungal endophytes: predicting the co-regulatory sequence motifs and the evolutionary history.

    Science.gov (United States)

    Kutil, Brandi L; Greenwald, Charles; Liu, Gang; Spiering, Martin J; Schardl, Christopher L; Wilkinson, Heather H

    2007-10-01

    LOL, a fungal secondary metabolite gene cluster found in Epichloë and Neotyphodium species, is responsible for production of insecticidal loline alkaloids. To analyze the genetic architecture and to predict the evolutionary history of LOL, we compared five clusters from four fungal species (single clusters from Epichloë festucae, Neotyphodium sp. PauTG-1, Neotyphodium coenophialum, and two clusters we previously characterized in Neotyphodium uncinatum). Using PhyloCon to compare putative lol gene promoter regions, we have identified four motifs conserved across the lol genes in all five clusters. Each motif has significant similarity to known fungal transcription factor binding sites in the TRANSFAC database. Conservation of these motifs is further support for the hypothesis that the lol genes are co-regulated. Interestingly, the history of asexual Neotyphodium spp. includes multiple interspecific hybridization events. Comparing clusters from three Neotyphodium species and E. festucae allowed us to determine which Epichloë ancestors are the most likely contributors of LOL in these asexual species. For example, while no present day Epichloë typhina isolates are known to produce lolines, our data support the hypothesis that the E. typhina ancestor(s) of three asexual endophyte species contained a LOL gene cluster. Thus, these data support a model of evolution in which the polymorphism in loline alkaloid production phenotypes among endophyte species is likely due to the loss of the trait over time.

  13. Conventional U-Pb dating versus SHRIMP of the Santa Barbara Granite Massif, Rondonia, Brazil

    Science.gov (United States)

    Sparrenberger, I.; Bettencourt, Jorge S.; Tosdal, R.M.; Wooden, J.L.

    2002-01-01

    The Santa Ba??rbara Granite Massif is part of the Younger Granites of Rondo??nia (998 - 974 Ma) and is included in the Rondo??nia Tin Province (SW Amazonian Craton). It comprises three highly fractionated metaluminous to peraluminous within-plate A-type granite units emplaced in older medium-grade metamorphic rocks. Sn-mineralization is closely associated with the late-stage unit. U-Pb monazite conventional dating of the early-stage Serra do Cicero facies and late-stage Serra Azul facies yielded ages of 993 ?? 5 Ma and 989 ?? 13 Ma, respectively. Conventional multigrain U-Pb isotope analyses of zircon demonstrate isotopic disturbance (discordance) and the preservation of inherited older zircons of several different ages and thus yield little about the ages of Sn-granite magmatism. SHRIMP U-Pb ages for the Santa Ba??rbara facies association yielded a 207Pb/206Pb weighted-mean age of 978 ?? 13 Ma. The textural complexity of the zircon crystals of the Santa Ba??rbara facies association, the variable concentrations of U, Th and Pb, as well as the mixed inheritance of zircon populations are major obstacles to using conventional multigrain U-Pb isotopic analyses. Sm-Nd model ages and ??Nd (T) values reveal anomalous isotopic data, attesting to the complex isotopic behaviour within these highly fractionated granites. Thus, SHRIMP U-Pb zircon and conventional U-Pb monazite dating methods are the most appropriate to constrain the crystallization age of the Sn-bearing granite systems in the Rondo??nia Tin Province.

  14. Comparison of five cluster validity indices performance in brain [18 F]FET-PET image segmentation using k-means.

    Science.gov (United States)

    Abualhaj, Bedor; Weng, Guoyang; Ong, Melissa; Attarwala, Ali Asgar; Molina, Flavia; Büsing, Karen; Glatting, Gerhard

    2017-01-01

    Dynamic [ 18 F]fluoro-ethyl-L-tyrosine positron emission tomography ([ 18 F]FET-PET) is used to identify tumor lesions for radiotherapy treatment planning, to differentiate glioma recurrence from radiation necrosis and to classify gliomas grading. To segment different regions in the brain k-means cluster analysis can be used. The main disadvantage of k-means is that the number of clusters must be pre-defined. In this study, we therefore compared different cluster validity indices for automated and reproducible determination of the optimal number of clusters based on the dynamic PET data. The k-means algorithm was applied to dynamic [ 18 F]FET-PET images of 8 patients. Akaike information criterion (AIC), WB, I, modified Dunn's and Silhouette indices were compared on their ability to determine the optimal number of clusters based on requirements for an adequate cluster validity index. To check the reproducibility of k-means, the coefficients of variation CVs of the objective function values OFVs (sum of squared Euclidean distances within each cluster) were calculated using 100 random centroid initialization replications RCI 100 for 2 to 50 clusters. k-means was performed independently on three neighboring slices containing tumor for each patient to investigate the stability of the optimal number of clusters within them. To check the independence of the validity indices on the number of voxels, cluster analysis was applied after duplication of a slice selected from each patient. CVs of index values were calculated at the optimal number of clusters using RCI 100 to investigate the reproducibility of the validity indices. To check if the indices have a single extremum, visual inspection was performed on the replication with minimum OFV from RCI 100 . The maximum CV of OFVs was 2.7 × 10 -2 from all patients. The optimal number of clusters given by modified Dunn's and Silhouette indices was 2 or 3 leading to a very poor segmentation. WB and I indices suggested in

  15. Comparison of Expression of Secondary Metabolite Biosynthesis Cluster Genes in Aspergillus flavus, A. parasiticus, and A. oryzae

    Directory of Open Access Journals (Sweden)

    Kenneth C. Ehrlich

    2014-06-01

    Full Text Available Fifty six secondary metabolite biosynthesis gene clusters are predicted to be in the Aspergillus flavus genome. In spite of this, the biosyntheses of only seven metabolites, including the aflatoxins, kojic acid, cyclopiazonic acid and aflatrem, have been assigned to a particular gene cluster. We used RNA-seq to compare expression of secondary metabolite genes in gene clusters for the closely related fungi A. parasiticus, A. oryzae, and A. flavus S and L sclerotial morphotypes. The data help to refine the identification of probable functional gene clusters within these species. Our results suggest that A. flavus, a prevalent contaminant of maize, cottonseed, peanuts and tree nuts, is capable of producing metabolites which, besides aflatoxin, could be an underappreciated contributor to its toxicity.

  16. Comparison of Expression of Secondary Metabolite Biosynthesis Cluster Genes in Aspergillus flavus, A. parasiticus, and A. oryzae

    Science.gov (United States)

    Ehrlich, Kenneth C.; Mack, Brian M.

    2014-01-01

    Fifty six secondary metabolite biosynthesis gene clusters are predicted to be in the Aspergillus flavus genome. In spite of this, the biosyntheses of only seven metabolites, including the aflatoxins, kojic acid, cyclopiazonic acid and aflatrem, have been assigned to a particular gene cluster. We used RNA-seq to compare expression of secondary metabolite genes in gene clusters for the closely related fungi A. parasiticus, A. oryzae, and A. flavus S and L sclerotial morphotypes. The data help to refine the identification of probable functional gene clusters within these species. Our results suggest that A. flavus, a prevalent contaminant of maize, cottonseed, peanuts and tree nuts, is capable of producing metabolites which, besides aflatoxin, could be an underappreciated contributor to its toxicity. PMID:24960201

  17. Comparison Of Keyword Based Clustering Of Web Documents By Using Openstack 4j And By Traditional Method

    Directory of Open Access Journals (Sweden)

    Shiza Anand

    2015-08-01

    Full Text Available As the number of hypertext documents are increasing continuously day by day on world wide web. Therefore clustering methods will be required to bind documents into the clusters repositories according to the similarity lying between the documents. Various clustering methods exist such as Hierarchical Based K-means Fuzzy Logic Based Centroid Based etc. These keyword based clustering methods takes much more amount of time for creating containers and putting documents in their respective containers. These traditional methods use File Handling techniques of different programming languages for creating repositories and transferring web documents into these containers. In contrast openstack4j SDK is a new technique for creating containers and shifting web documents into these containers according to the similarity in much more less amount of time as compared to the traditional methods. Another benefit of this technique is that this SDK understands and reads all types of files such as jpg html pdf doc etc. This paper compares the time required for clustering of documents by using openstack4j and by traditional methods and suggests various search engines to adopt this technique for clustering so that they give result to the user querries in less amount of time.

  18. Environmental Audit at Santa Barbara Operations, Special Technologies Laboratory, Remote Sensing Laboratory, North Las Vegas Facilities

    International Nuclear Information System (INIS)

    1991-03-01

    This report documents the results of the Environmental Audit of selected facilities under the jurisdiction of the DOE Nevada Operations Office (NV) that are operated by EG and G Energy Measurements, Incorporated (EG and G/EM). The facilities included in this Audit are those of Santa Barbara Operation (SBO) at Goleta, California; the Special Technologies Laboratory (STL) at Santa Barbara, California; and Las Vegas Area Operations (LVAO) including the Remote Sensing Laboratory (RSL) at Nellis Air Force Base in Nevada, and the North Las Vegas Facilities (NLVF) at North Las Vegas, Nevada. The Environmental Audit was conducted by the US Department of Energy's (DOE) Office of Environmental Audit, commencing on January 28, 1991 and ending on February 15, 1991. The scope of the Audit was comprehensive, addressing environmental activities in the technical areas of air, surface water/drinking water, groundwater, waste management, toxic and chemical materials, quality assurance, radiation, inactive waste sites, and environmental management. Also assessed was compliance with applicable Federal, state, and local regulations and requirements; internal operating requirements; DOE Orders; and best management practices. 8 tabs

  19. Throat Patch Variation in Tayra (Eira barbara and the Potential for Individual Identification in the Field

    Directory of Open Access Journals (Sweden)

    Álvaro José Villafañe-Trujillo

    2018-01-01

    Full Text Available The importance of identifying individuals of a population has been extensively documented in several species of carnivores, including some species of mustelids. This information is used in many kinds of ecological studies including density estimation, behavioral ecology and analyses of animal movement patterns. The objective of the present study was to determine if individual variation in the throat patches of Tayra (Eira barbara permits individual identification. We examined 275 specimens from museum collections to determine the morphological variation of the throat patch in Eira barbara specimens collected throughout its distribution. We found differences in the shape and size of the throat patches significant enough to allow discrimination of individuals that display a throat patch (88.0% of 252 complete specimens. The proposed identification criterion was applied to photographic records obtained from a wild population using camera traps in the Peruvian Amazon. From nineteen images (54.0% of all images in which the throat patch was visible, nine different individuals were identified and two of these were recaptured on multiple occasions.

  20. Comparison of Skin Moisturizer: Consumer-Based Brand Equity (CBBE Factors in Clusters Based on Consumer Ethnocentrism

    Directory of Open Access Journals (Sweden)

    Yossy Hanna Garlina

    2014-09-01

    Full Text Available This research aims to analyze relevant factors contributing to the four dimensions of consumer-based brand equity in skin moisturizer industry. It is then followed by the clustering of female consumers of skin moisturizer based on ethnocentrism and differentiating each cluster’s consumer-based brand equity dimensions towards a domestic skin moisturizer brand Mustika Ratu, skin moisturizer. Research used descriptive survey method analysis. Primary data was obtained through questionnaire distribution to 70 female respondents for factor analysis and 120 female respondents for cluster analysis and one way analysis of variance (ANOVA. This research employed factor analysis to obtain relevant factors contributing to the five dimensions of consumer-based brand equity in skin moisturizer industry. Cluster analysis and one way analysis of variance (ANOVA were to see the difference of consumer-based brand equity between highly ethnocentric consumer and low ethnocentric consumer towards the same skin moisturizer domestic brand, Mustika Ratu skin moisturizer. Research found in all individual dimension analysis, all variable means and individual means show distinct difference between the high ethnocentric consumer and the low ethnocentric consumer. The low ethnocentric consumer cluster tends to be lower in mean score of Brand Loyalty, Perceived Quality, Brand Awareness, Brand Association, and Overall Brand Equity than the high ethnocentric consumer cluster. Research concludes consumer ethnocentrism is positively correlated with preferences towards domestic products and negatively correlated with foreign-made product preference. It is, then, highly ethnocentric consumers have positive perception towards domestic product.

  1. Comparison of pressure profiles of massive relaxed galaxy clusters using the Sunyaev-Zel'dovich and x-ray data

    International Nuclear Information System (INIS)

    Bonamente, Massimiliano; Hasler, Nicole; Bulbul, Esra; Landry, David; Carlstrom, John E; Culverhouse, Thomas L; Gralla, Megan; Greer, Christopher; Hennessy, Ryan; Leitch, Erik M; Plagge, Thomas; Pryke, Clem; Hawkins, David; Lamb, James W; Muchovej, Stephen; Joy, Marshall; Kolodziejczak, Jeffery; Marrone, Daniel P; Miller, Amber; Mroczkowski, Tony

    2012-01-01

    We present the Sunyaev-Zel'dovich (SZ) effect observations of a sample of 25 massive relaxed galaxy clusters observed with the Sunyaev-Zel'dovich array (SZA), an eight-element interferometer that is part of the Combined Array for Research in Millimeter-wave Astronomy (CARMA). We performed an analysis of new SZA data and archival Chandra observations of this sample to investigate the integrated pressure—a proxy for cluster mass—determined from x-ray and SZ observations, two independent probes of the intra-cluster medium (ICM). This analysis makes use of a model for the ICM introduced by Bulbul (2010 Astrophys. J. 720 1038) which can be applied simultaneously to the SZ and x-ray data. With this model, we estimated the pressure profile for each cluster using a joint analysis of the SZ and x-ray data, and using the SZ data alone. We found that the integrated pressures measured from the x-ray and SZ data are consistent. This conclusion is in agreement with recent results obtained using WMAP and Planck data, confirming that SZ and x-ray observations of massive clusters detect the same amount of thermal pressure from the ICM. To test for possible biases introduced by our choice of model, we also fitted the SZ data using the universal pressure profile proposed by Arnaud (2010 Astron. Astrophys. 517 A92) and found consistency between the two models out to r 500 in the pressure profiles and integrated pressures. (paper)

  2. Comparison of methods for estimating the intraclass correlation coefficient for binary responses in cancer prevention cluster randomized trials.

    Science.gov (United States)

    Wu, Sheng; Crespi, Catherine M; Wong, Weng Kee

    2012-09-01

    The intraclass correlation coefficient (ICC) is a fundamental parameter of interest in cluster randomized trials as it can greatly affect statistical power. We compare common methods of estimating the ICC in cluster randomized trials with binary outcomes, with a specific focus on their application to community-based cancer prevention trials with primary outcome of self-reported cancer screening. Using three real data sets from cancer screening intervention trials with different numbers and types of clusters and cluster sizes, we obtained point estimates and 95% confidence intervals for the ICC using five methods: the analysis of variance estimator, the Fleiss-Cuzick estimator, the Pearson estimator, an estimator based on generalized estimating equations and an estimator from a random intercept logistic regression model. We compared estimates of the ICC for the overall sample and by study condition. Our results show that ICC estimates from different methods can be quite different, although confidence intervals generally overlap. The ICC varied substantially by study condition in two studies, suggesting that the common practice of assuming a common ICC across all clusters in the trial is questionable. A simulation study confirmed pitfalls of erroneously assuming a common ICC. Investigators should consider using sample size and analysis methods that allow the ICC to vary by study condition. Copyright © 2012. Published by Elsevier Inc.

  3. Comparison of nano-sized Mn oxides with the Mn cluster of photosystem II as catalysts for water oxidation.

    Science.gov (United States)

    Najafpour, Mohammad Mahdi; Ghobadi, Mohadeseh Zarei; Haghighi, Behzad; Tomo, Tatsuya; Shen, Jian-Ren; Allakhverdiev, Suleyman I

    2015-02-01

    "Back to Nature" is a promising way to solve the problems that we face today, such as air pollution and shortage of energy supply based on conventional fossil fuels. A Mn cluster inside photosystem II catalyzes light-induced water-splitting leading to the generation of protons, electrons and oxygen in photosynthetic organisms, and has been considered as a good model for the synthesis of new artificial water-oxidizing catalysts. Herein, we surveyed the structural and functional details of this cluster and its surrounding environment. Then, we review the mechanistic findings concerning the cluster and compare this biological catalyst with nano-sized Mn oxides, which are among the best artificial Mn-based water-oxidizing catalysts. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Status of groundwater quality in the Santa Barbara Study Unit, 2011: California GAMA Priority Basin Project

    Science.gov (United States)

    Davis, Tracy A.; Kulongoski, Justin T.

    2016-10-03

    Groundwater quality in the 48-square-mile Santa Barbara study unit was investigated in 2011 as part of the California State Water Resources Control Board’s Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project. The study unit is mostly in Santa Barbara County and is in the Transverse and Selected Peninsular Ranges hydrogeologic province. The GAMA Priority Basin Project is carried out by the U.S. Geological Survey in collaboration with the California State Water Resources Control Board and Lawrence Livermore National Laboratory.The GAMA Priority Basin Project was designed to provide a statistically unbiased, spatially distributed assessment of the quality of untreated groundwater in the primary aquifer system of California. The primary aquifer system is defined as that part of the aquifer corresponding to the perforation interval of wells listed in the California Department of Public Health database for the Santa Barbara study unit. This status assessment is intended to characterize the quality of groundwater resources in the primary aquifer system of the Santa Barbara study unit, not the treated drinking water delivered to consumers by water purveyors.The status assessment for the Santa Barbara study unit was based on water-quality and ancillary data collected in 2011 by the U.S. Geological Survey from 23 sites and on water-quality data from the California Department of Public Health database for January 24, 2008–January 23, 2011. The data used for the assessment included volatile organic compounds; pesticides; pharmaceutical compounds; two constituents of special interest, perchlorate and N-nitrosodimethylamine (NDMA); and naturally present inorganic constituents, such as major ions and trace elements. Relative-concentrations (sample concentration divided by the health- or aesthetic-based benchmark concentration) were used to evaluate groundwater quality for those constituents that have federal or California regulatory and non

  5. A Comparison of Mean Models and Clustering Techniques for Vertebra Detection and Region Separation from C-Spine X-Rays

    Directory of Open Access Journals (Sweden)

    Anum Mehmood

    2017-09-01

    Full Text Available In Computer Aided Diagnosis (CAD tools, vertebra localization and detection are the essential steps for the diagnosis of cervical spine injuries. The accurate localization leads to accurate treatment, which is more challenging in case of poor contrast and noisy radiographs. This paper targets c-spine radiographs for the localization of vertebra using different vertebra templates, vertebra detection at each level using two different clustering techniques and gives a comparison between them. Moreover it separates the regions for each individual c-spine. It takes the poor contrast x-ray as input, enhance the contrast and detect the edges of enhanced image. After the edge detection, manually selected Region of Interest (ROI helps in getting the edges of area covering C3 – C7 only. These edges along with 4 different template models of vertebra are used for the localization by Generalized Hough Transform (GHT. The results obtained are analyzed visually for the best localization template. Then, on voted points obtained after pruning, two clustering techniques Fuzzy C Means and K-Means are applied separately, to form clusters and centroids for each vertebra. Another part of this paper is to separate vertebra regions. For this, intervertebral points are calculated and then along these points, centroids are rotated using Affine Transformation. It gives parallel lines to vertebrae and joining them gives region for each vertebra. The comparison and testing of proposed technique has been performed using dataset ‘NHANES II’ publicly accessible at ‘The National Library of Medicine’, total 150 cervical spine scans are used securing accuracies 93:76%, 84:21% and 83:1% for FCM, K-Means and region separation, respectively.

  6. A Mitigation Process for Impacts of the All American Pipeline on Oak Woodlands in Santa Barbara County

    Science.gov (United States)

    Germaine Reyes-French; Timothy J. Cohen

    1991-01-01

    This paper outlines a mitigation program for pipeline construction impacts to oak tree habitat by describing the requirements for the Offsite Oak Mitigation Program for the All American Pipeline (AAPL) in Santa Barbara County, California. After describing the initial environmental analysis, the County regulatory structure is described under which the plan was required...

  7. Page 1 48 V V S Sarma Garcia-Molina H, Barbara D 1984 Proc. 4th ...

    Indian Academy of Sciences (India)

    Garcia-Molina H, Barbara D 1984 Proc. 4th Int. Conf. on Distributed Computing Systems (Silver. Spring, MD: IEEE Comput. Soc. Press) pp. 340–346 -. Goel A 1983 A Guidebook for Software Reliability Assessment, Tech. Rept. 83–11 (New York,. Syracuse Univ. Dept. Ind. Eng. & OR). Goel A 1985 IEEE Trans. Software Eng.

  8. 78 FR 21580 - Revisions to the California State Implementation Plan, Santa Barbara and San Diego County Air...

    Science.gov (United States)

    2013-04-11

    ... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Santa Barbara and San Diego... District (SBCAPCD) and San Diego County Air Pollution Control District (SDCAPCD) portions of the California.... Federal eRulemaking Portal: www.regulations.gov . Follow the on- line instructions. 2. Email: steckel...

  9. 78 FR 21537 - Revisions to the California State Implementation Plan, Santa Barbara and San Diego County Air...

    Science.gov (United States)

    2013-04-11

    ... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Santa Barbara and San Diego... Air Pollution Control District (SBCAPCD) and San Diego County Air Pollution Control District (SDCAPCD..., by one of the following methods: 1. Federal eRulemaking Portal: www.regulations.gov . Follow the on...

  10. "Romeo ja Julia" Liivimaa moodi? Barbara von Tiesenhauseni legend : ajalooline tagapõhi ja kirjanduslikud variatsioonid / Juhan Kreem, Liina Lukas

    Index Scriptorium Estoniae

    Kreem, Juhan

    2008-01-01

    Käsitletakse järgnevaid ilukirjanduslikke teoseid: Fr. R. Kreutzwaldi ballaadi "Das Fräulein von Borkholm", Th. H. Panteniuse romaani "Die von Kelles" (e.k. "Kelleste omad. Romaan Liivimaa minevikust"), Marie Underi ballaadi "Porkuni preili", Aino Kallase novelli "Barbara von Tiesenhusen" ja Maimu Bergi romaani "Kirjutajad"

  11. Prospective thinking in a mustelid? Eira barbara (Carnivora) cache unripe fruits to consume them once ripened

    Science.gov (United States)

    Soley, Fernando G.; Alvarado-Díaz, Isaías

    2011-08-01

    The ability of nonhuman animals to project individual actions into the future is a hotly debated topic. We describe the caching behaviour of tayras ( Eira barbara) based on direct observations in the field, pictures from camera traps and radio telemetry, providing evidence that these mustelids pick and cache unripe fruit for future consumption. This is the first reported case of harvesting of unripe fruits by a nonhuman animal. Ripe fruits are readily taken by a variety of animals, and tayras might benefit by securing a food source before strong competition takes place. Unripe climacteric fruits need to be harvested when mature to ensure that they continue their ripening process, and tayras accurately choose mature stages of these fruits for caching. Tayras cache both native (sapote) and non-native (plantain) fruits that differ in morphology and developmental timeframes, showing sophisticated cognitive ability that might involve highly developed learning abilities and/or prospective thinking.

  12. Biotic response to late Quaternary rapid climate switches in Santa Barbara Basin: Ecological and evolutionary implications

    International Nuclear Information System (INIS)

    Cannariato, K.G.; Kennett, J.P.; Behl, R.J.

    1999-01-01

    Benthic foraminiferal assemblages from Santa Barbara Basin exhibit major faunal and ecological switches associated with late Quaternary millennial- to decadal-scale global climate oscillations. Repeated turnovers of entire faunas occurred rapidly (<40--400 yr) without extinction or speciation in conjunction with Dansgaard-Oeschger shifts in thermohaline circulation, ventilation, and climate, confirming evolutionary model predictions of Roy et al. Consistent faunal successions of dysoxic taxa during successive interstadials reflect the extreme sensitivity and adaptation of the benthic ecosystem to the rapid environmental changes that marked the late Quaternary and possibly other transitional intervals in the history of the Earth's ocean-atmosphere-cryosphere system. These data support the hypothesis that broad segments of the biosphere are well adapted to rapid climate change

  13. Dad's in the Garage: Santa Barbara Physicists in the Long 1970s

    Science.gov (United States)

    Mody, Cyrus

    2013-03-01

    American physicists faced many challenges in the 1970s: declining research budgets; public skepticism of scientific authority; declining student enrollments; and pressure to shift to topics such as biomedicine, environmental remediation, alternative energy, public housing and transport, and disability technologies. This paper examines the responses to these challenges of a small group of Santa Barbara physicists. While this group is not representative of the American physics profession, the success and failure of their responses to changed conditions tells us something about how American physicists got through the 1970s, and about the origins of some features of American physics today. The three physicists examined here are Philip Wyatt, David Phillips, and Virgil Elings. In the late `60s, Wyatt left a defense think tank to found an instrumentation firm. The Santa Barbara oil spill and other factors pushed that firm toward civilian markets in biomedicine and pollution measurement. Phillips joined Wyatt's firm from UCSB, while also founding his own company, largely to sell electronic devices for parapsychology. Phillips was also the junior partner in a master's of scientific instrumentation degree curriculum founded by Elings in order to save UCSB Physics' graduate program. Through the MSI program, Elings moved into biomedical research and became a serial entrepreneur. By the 1990s, Wyatt, Phillips, and Elings' turn toward academic entrepreneurship, dual military-civilian markets for physics start-ups, and interdisciplinary collaborations between physicists and life scientists were no longer unusual. Together, their journey through the `70s shows how varied the physics' profession's response to crisis was, and how much it pivoted on new interactions between university and industry.

  14. Automatic determination of the arterial input function in dynamic susceptibility contrast MRI: comparison of different reproducible clustering algorithms

    International Nuclear Information System (INIS)

    Yin, Jiandong; Yang, Jiawen; Guo, Qiyong

    2015-01-01

    Arterial input function (AIF) plays an important role in the quantification of cerebral hemodynamics. The purpose of this study was to select the best reproducible clustering method for AIF detection by comparing three algorithms reported previously in terms of detection accuracy and computational complexity. First, three reproducible clustering methods, normalized cut (Ncut), hierarchy (HIER), and fast affine propagation (FastAP), were applied independently to simulated data which contained the true AIF. Next, a clinical verification was performed where 42 subjects participated in dynamic susceptibility contrast MRI (DSC-MRI) scanning. The manual AIF and AIFs based on the different algorithms were obtained. The performance of each algorithm was evaluated based on shape parameters of the estimated AIFs and the true or manual AIF. Moreover, the execution time of each algorithm was recorded to determine the algorithm that operated more rapidly in clinical practice. In terms of the detection accuracy, Ncut and HIER method produced similar AIF detection results, which were closer to the expected AIF and more accurate than those obtained using FastAP method; in terms of the computational efficiency, the Ncut method required the shortest execution time. Ncut clustering appears promising because it facilitates the automatic and robust determination of AIF with high accuracy and efficiency. (orig.)

  15. LCD versus CRT monitors for digital mammography: a comparison of observer performance for the detection of clustered microcalcifications and masses.

    Science.gov (United States)

    Cha, Joo Hee; Moon, Woo Kyung; Cho, Nariya; Lee, Eun Hye; Park, Jeong Seon; Jang, Mi Jung

    2009-12-01

    There are two types of soft-copy display of digital mammograms, cathode-ray tube (CRT) and liquid-crystal display (LCD) monitors, and these present different resolutions and noise characteristics. To compare observer performances for the detection of clustered microcalcifications and masses in digital mammograms, using LCD and CRT monitors. Four radiologists evaluated 100 digital mammograms. Of these, 28 mammograms depicted clustered microcalcifications (12 benign, 16 malignant), 18 depicted masses (10 benign, eight malignant), and 54 depicted no apparent abnormality. The images were stored uncompressed as Digital Imaging and Communications in Medicine (DICOM) files and randomized for two sessions of soft-copy reading. The readers independently read all cases displayed on two 5-megapixel LCD and two CRT monitors with an interval of 3 months. Observers were asked to rate using a five-point scale the likelihoods of microcalcifications and masses independently. Receiver operating characteristic analysis was used to analyze results. For the LCD and CRT monitors, average area-under-the-curve (A(z)) values for microcalcification detection were 0.977 (0.976, 0.970, 0.980, and 0.983 for the four readers) and 0.958 (0.910, 0.990, 0.976, 0.956), respectively. Corresponding A(z) values for masses were 0.971 (0.955, 0.990, 0.949, 0.989) and 0.944 (0.928, 0.966, 0.955, 0.925). No statistically significant difference was detected between the two monitor types (P>0.05). The LCD and CRT monitors are comparable in terms of detecting clustered microcalcifications and masses in digital mammograms.

  16. Thermodynamics of Small Alkali Metal Halide Cluster Ions: Comparison of Classical Molecular Simulations with Experiment and Quantum Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Vlcek, Lukas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Uhlik, Filip [Charles Univ., Prague (Czech Republic); Moucka, Filip [Purkinje Univ. (Czech Republic); Nezbeda, Ivo [Purkinje Univ. (Czech Republic); Academy of Sciences of the Czech Republic (ASCR), Prague (Czech Republic); Chialvo, Ariel A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-12-16

    We evaluate the ability of selected classical molecular models to describe the thermodynamic and structural aspects of gas-phase hydration of alkali halide ions and the formation of small water clusters. To understand the effect of many-body interactions (polarization) and charge penetration effects on the accuracy of a force field, we perform Monte Carlo simulations with three rigid water models using different functional forms to account for these effects: (i) point charge non-polarizable SPC/E, (ii) Drude point charge polarizable SWM4- DP, and (iii) Drude Gaussian charge polarizable BK3. Model predictions are compared with experimental Gibbs free energies and enthalpies of ion hydration, and with microscopic structural properties obtained from quantum DFT calculations. We find that all three models provide comparable predictions for pure water clusters and cation hydration, but differ significantly in their description of anion hydration. None of the investigated classical force fields can consistently and quantitatively reproduce the experimental gas phase hydration thermodynamics. The outcome of this study highlights the relation between the functional form that describes the effective intermolecular interactions and the accuracy of the resulting ion hydration properties.

  17. Comparison of Molecular Typing Methods Useful for Detecting Clusters of Campylobacter jejuni and C. coli Isolates through Routine Surveillance

    Science.gov (United States)

    Taboada, Eduardo; Grant, Christopher C. R.; Blakeston, Connie; Pollari, Frank; Marshall, Barbara; Rahn, Kris; MacKinnon, Joanne; Daignault, Danielle; Pillai, Dylan; Ng, Lai-King

    2012-01-01

    Campylobacter spp. may be responsible for unreported outbreaks of food-borne disease. The detection of these outbreaks is made more difficult by the fact that appropriate methods for detecting clusters of Campylobacter have not been well defined. We have compared the characteristics of five molecular typing methods on Campylobacter jejuni and C. coli isolates obtained from human and nonhuman sources during sentinel site surveillance during a 3-year period. Comparative genomic fingerprinting (CGF) appears to be one of the optimal methods for the detection of clusters of cases, and it could be supplemented by the sequencing of the flaA gene short variable region (flaA SVR sequence typing), with or without subsequent multilocus sequence typing (MLST). Different methods may be optimal for uncovering different aspects of source attribution. Finally, the use of several different molecular typing or analysis methods for comparing individuals within a population reveals much more about that population than a single method. Similarly, comparing several different typing methods reveals a great deal about differences in how the methods group individuals within the population. PMID:22162562

  18. Automotive and aeronautical clusters in the São Paulo state’s Vale do Paraíba: a comparison of formation trajectories

    Directory of Open Access Journals (Sweden)

    Márcio da Silveira Luz

    2010-04-01

    Full Text Available This paper presents a comparison of the relevant characteristics of São Paulo State’s Vale do Paraíba automotive and aerospace clusters observed and analyzes the technological and productive chains strengthening. In order to accomplish it, the adopted methodological procedures are of qualitative nature, by means of documentary research. The results pointed out that the government established, in the mid-1945, the currently named Departamento de Ciência e Tecnologia Aeroespacial (DCTA, as a research and development (R&D center and, by 1979, Embraer, a state-owned aeronautical construction industry. It was also sought to generate conditions so that domestic companies could emerge around and replace the dependency on aerospace systems and subsystems international suppliers by developing indigenous technological capacities. The automotive cluster under study started in the São Paulo State’s Vale do Paraíba (PPV by means of the regionalization of multinational automotive construction firms migrated from ABC Paulista region looking for physical space for their growth, also relying on tax benefits. The survey results indicate that, in spite of fundamental differences with regard to their productive chains strenghtening processes, they showed similar adverse results.

  19. A Comparison of Optimal Operation of a Residential Fuel Cell Co-Generation System Using Clustered Demand Patterns Based on Kullback-Leibler Divergence

    Directory of Open Access Journals (Sweden)

    Takumi Hasizume

    2013-01-01

    Full Text Available When evaluating residential energy systems like co-generation systems, hot water and electricity demand profiles are critical. In this paper, the authors aim to extract basic time-series demand patterns from two kinds of measured demand (electricity and domestic hot water, and also aim to reveal effective demand patterns for primary energy saving. Time-series demand data are categorized with a hierarchical clustering method using a statistical pseudo-distance, which is represented by the generalized Kullback-Leibler divergence of two Gaussian mixture distributions. The classified demand patterns are built using hierarchical clustering and then a comparison is made between the optimal operation of a polymer electrolyte membrane fuel cell co-generation system and the operation of a reference system (a conventional combination of a condensing gas boiler and electricity purchased from the grid using the appropriately built demand profiles. Our results show that basic demand patterns are extracted by the proposed method, and the heat-to-power ratio of demand, the amount of daily demand, and demand patterns affect the primary energy saving of the co-generation system.

  20. CLEAN: CLustering Enrichment ANalysis

    Science.gov (United States)

    Freudenberg, Johannes M; Joshi, Vineet K; Hu, Zhen; Medvedovic, Mario

    2009-01-01

    -expressed genes over using the traditional cluster-wide scores. Using gene-specific coherence scores also simplifies the comparisons of clusterings produced by different clustering algorithms and provides a simple tool for selecting genes with a "functionally coherent" expression profile. PMID:19640299

  1. Cluster headache

    Science.gov (United States)

    Histamine headache; Headache - histamine; Migrainous neuralgia; Headache - cluster; Horton's headache; Vascular headache - cluster ... Doctors do not know exactly what causes cluster headaches. They ... (chemical in the body released during an allergic response) or ...

  2. Analysis of Radiation Damage in Light Water Reactors: Comparison of Cluster Analysis Methods for the Analysis of Atom Probe Data.

    Science.gov (United States)

    Hyde, Jonathan M; DaCosta, Gérald; Hatzoglou, Constantinos; Weekes, Hannah; Radiguet, Bertrand; Styman, Paul D; Vurpillot, Francois; Pareige, Cristelle; Etienne, Auriane; Bonny, Giovanni; Castin, Nicolas; Malerba, Lorenzo; Pareige, Philippe

    2017-04-01

    Irradiation of reactor pressure vessel (RPV) steels causes the formation of nanoscale microstructural features (termed radiation damage), which affect the mechanical properties of the vessel. A key tool for characterizing these nanoscale features is atom probe tomography (APT), due to its high spatial resolution and the ability to identify different chemical species in three dimensions. Microstructural observations using APT can underpin development of a mechanistic understanding of defect formation. However, with atom probe analyses there are currently multiple methods for analyzing the data. This can result in inconsistencies between results obtained from different researchers and unnecessary scatter when combining data from multiple sources. This makes interpretation of results more complex and calibration of radiation damage models challenging. In this work simulations of a range of different microstructures are used to directly compare different cluster analysis algorithms and identify their strengths and weaknesses.

  3. A comparison of neural network and fuzzy clustering techniques in segmenting magnetic resonance images of the brain

    Science.gov (United States)

    Hall, Lawrence O.; Bensaid, Amine M.; Clarke, Laurence P.; Velthuizen, Robert P.; Silbiger, Martin S.; Bezdek, James C.

    1992-01-01

    Magnetic resonance (MR) brain section images are segmented and then synthetically colored to give visual representations of the original data with three approaches: the literal and approximate fuzzy c-means unsupervised clustering algorithms and a supervised computational neural network, a dynamic multilayered perception trained with the cascade correlation learning algorithm. Initial clinical results are presented on both normal volunteers and selected patients with brain tumors surrounded by edema. Supervised and unsupervised segmentation techniques provide broadly similar results. Unsupervised fuzzy algorithms were visually observed to show better segmentation when compared with raw image data for volunteer studies. However, for a more complex segmentation problem with tumor/edema or cerebrospinal fluid boundary, where the tissues have similar MR relaxation behavior, inconsistency in rating among experts was observed.

  4. Report on data from the Nearshore Sediment Transport Study experiment at Leadbetter Beach, Santa Barbara, California, January-February 1980 (NODC Accession 8200080)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — THIS DATA SET CONSISTS OF THE RESULTS OF THE NEARSHORE SEDIMENT Nearshore Sediment Transport Study at Leadbetter Beach, Santa Barbara, California. These data from 28...

  5. Rita Braches-Chyrek, Jane Addams, Mary Richmond und Alice Salomon: Professionalisierung und Disziplinbildung Sozialer Arbeit. Opladen: Barbara Budrich 2013 (340 S.) [Rezension

    OpenAIRE

    Lau, Dayana

    2013-01-01

    Rezension von: Rita Braches-Chyrek, Jane Addams, Mary Richmond und Alice Salomon: Professionalisierung und Disziplinbildung Sozialer Arbeit. Opladen: Barbara Budrich 2013 (340 S.; ISBN 978-3-8474-0015-8)

  6. The Old Spanish Days Fiesta in Santa Barbara, California: Cultural Hybridity, Colonial Mythologies and the Romanticization of a Latino Heritage

    Directory of Open Access Journals (Sweden)

    Patricia Ann Hardwick

    2010-12-01

    Full Text Available Old Spanish Days Fiesta is a tradition that was invented in 1924 by civic leaders in Santa Barbara, California to celebrate the periods of the Spanish settlement and the Mexican rule of California and to promote local tourism. This article will trace the historical narrative of the complex cultural and ethnic composition of Santa Barbara before interrogating the colonial and post-colonial histories of the Californian past that are so often romanticized during the events of the Santa Barbara Fiesta. Subsequent to the American appropriation of California, Anglo-American ideas of race and identity were imposed upon Latino Californians. This development led many Spanish-speaking Californians to cultivate a Spanish identity and de-emphasize their Mexican, Native American, or African ancestry as they attempted to maintain their land grants and social prominence under American rule. Official versions of Santa Barbara’s past promoted by Santa Barbara’s civic leaders and Old Spanish Days Fiesta literature tend to privilege romanticized historical interpretations that submerge and absorb California’s hybrid ethnic and cultural histories into an idealized Spanish colonial narrative. This article explores how many individual Santa Barbara Fiesteros choose to engage, negotiate, and/or subvert this simplified official civic narrative of Santa Barbara’s Spanish past through their own personal performances during the Fiesta. An analysis of how local festival participants envision their performance in the context of the festival allows outsiders to have a glimpse into how they create and embody their own personal and nuanced understandings of history during the Fiesta.

  7. Mateship and the Female Body in Barbara Baynton's “Squeaker's Mate”

    Directory of Open Access Journals (Sweden)

    Deborah Scheidt

    2015-01-01

    Full Text Available http://dx.doi.org/10.5007/2175-8026.2015v68n2p67 “Mateship”, or companionship and loyalty in adverse situations, was a common theme for late 19th century Australian short stories. Women are excluded from the practice of mateship and are not usually the protagonists of these narratives, being either kept in the background as mothers and housewives, or not present at all in the plots.  Going against these stereotypes, in Barbara Baynton’s story “Squeaker’s Mate”, the “mate” is an independent, strong and hard-working woman. Baynton explores the gloomy consequences of this reversal of expected gender roles, especially after an accident leaves the protagonist paralysed and no longer in control of her body. What occurs in “Squeaker’s Mate” is a kind of “anti-mateship”, where irony serves as a device to expose gender relations and the exclusion of women from what is traditionally considered heroic and historical. In “Squeaker’s Mate”, Baynton questioned the adoption of “mateship” as an Australian value more than half a century before that discussion started to draw formal critical attention.

  8. Initial source and site characterization studies for the U.C. Santa Barbara campus

    Energy Technology Data Exchange (ETDEWEB)

    Archuleta, R.; Nicholson, C.; Steidl, J.; Gurrola, L.; Alex, C.; Cochran, E.; Ely, G.; Tyler, T. [University of California, Santa Barbara (United States)

    1997-12-01

    The University of California Campus-Laboratory Collaboration (CLC) project is an integrated 3 year effort involving Lawrence Livermore National Laboratory (LLNL) and four UC campuses - Los Angeles (UCLA), Riverside (UCR), Santa Barbara (UCSB), and San Diego (UCSD) - plus additional collaborators at San Diego State University (SDSU), at Los Alamos National Laboratory and in industry. The primary purpose of the project is to estimate potential ground motions from large earthquakes and to predict site-specific ground motions for one critical structure on each campus. This project thus combines the disciplines of geology, seismology, geodesy, soil dynamics, and earthquake engineering into a fully integrated approach. Once completed, the CLC project will provide a template to evaluate other buildings at each of the four UC campuses, as well as provide a methodology for evaluating seismic hazards at other critical sites in California, including other UC locations at risk from large earthquakes. Another important objective of the CLC project is the education of students and other professional in the application of this integrated, multidisciplinary, state-of-the-art approach to the assessment of earthquake hazard. For each campus targeted by the CLC project, the seismic hazard study will consist of four phases: Phase I - Initial source and site characterization, Phase II - Drilling, logging, seismic monitoring, and laboratory dynamic soil testing, Phase III - Modeling of predicted site-specific earthquake ground motions, and Phase IV - Calculations of 3D building response. This report cover Phase I for the UCSB campus and incudes results up through March 1997.

  9. Anomalously high uplift rates along the Ventura-Santa Barbara Coast, California-tectonic implications

    Science.gov (United States)

    Wehmiller, J. F.; Sarna-Wojcicki, A.; Yerkes, R.F.; Lajoie, K.R.

    1979-01-01

    The NW-SE trending segments of the California coastline from Point Arena to Point Conception (500 km) and from Los Angeles to San Diego (200 km) generally parallel major right-lateral strike-slip fault systems. Minor vertical crustal movements associated with the dominant horizontal displacements along these fault systems are recorded in local sedimentary basins and slightly deformed marine terraces. Typical maximum uplift rates during Late Quaternary time are about 0.3 m/ka, based on U-series ages of corals and amino-acid age estimates of fossil mollusks from the lowest emergent terraces. In contrast, the E-W-trending segments of the California coastline between Point Conception and Los Angeles (200 km) parallel predominantly northward-dipping thrust and high-angle reverse faults of the western Transverse Ranges. Along this coast, marine terraces display significantly greater vertical deformation. Amino-acid age estimates of mollusks from elevated marine terraces along the Ventura-Santa Barbara coast imply anomalously high uplift rates of between 1 and 6 m/ka over the past 40 to 100 ka. The deduced rate of terrace uplift decreases from Ventura to Los Angeles, conforming with a similar trend observed by others in contemporary geodetic data. The more rapid rates of terrace uplift in the western Transverse Ranges reflect N-S crustal shortening that is probably a local accommodation of the dominant right-lateral shear strain along coastal California. ?? 1979.

  10. Text as Locus, Inscription as Identity: On Barbara Honigmann's Roman von einem Kinde

    Directory of Open Access Journals (Sweden)

    Marilyn Sibley Fries

    1990-06-01

    Full Text Available Barbara Honigmann's Roman von einem Kinde (1986 constitutes the author's attempt at narrative self-definition. In this and other regards, it is similar to Christa Wolf's Kindheitsmuster (1976; Patterns of Childhood, 1980 , with which it is briefly compared. Honigmann's slim collection of stories, conceived by her as "sketches for self-portraits and landscapes," depicts the absolute isolation ofthe female Jewish narrator in the GDR and her search for community ( Heimat via language. Simultaneously, it records that narrator's desire to identify "places of transition," "boundaries at which conditions change" without fixing these in a static prison of text. The narrator-mother merges with the child born in the first story as, in the following ones, she comprehends the insignificance of her social (context, finally to simulate her own birth and the envied preverbal infant stage by means of self-expulsion—from the GDR via a "threefold salto mortale into the "Judaism of the Thora" in Strasbourg—into a "foreign language among foreign people." The narrator/author's position at a transitional boundary, underscored by the self-portrait that adorns the book's dust jacket, acknowledges the territory between two illegible texts and her reluctance to sacrifice "true reality" ( wahre Wirklichkeit by transforming "human being" into "text" ( Mensch into Schrift —a reluctance engendered by her meeting with Gershom Scholem in the central story of the volume.

  11. Remote sensing study of historical changes in natural oil slick volumes in the Santa Barbara Channel

    Energy Technology Data Exchange (ETDEWEB)

    Scepan, J.; Estes, J.; Hornafius, J.S. (Univ. of California, Santa Barbara, CA (United States))

    1996-01-01

    Large natural oil slicks are continually forming in the Santa Barbara Channel as a result of natural hydrocarbon seeps that occur above subsurface oil accumulations. Evaporation of volatile constituents in these oil slicks is a significant source of air pollution. In this study we employed a suite of remote sensing data along with a variety of image processing and geographic information system techniques to analyze the location, extent and changes in sea surface oil slicks during the period of 1975 - present. An extensive collection of airborne and spaceborne remote sensor data was accessed and examined for this study, including aerial photography, airborne spectral and microwave data, Landsat MSS and TM data and Shuttle Imaging Radar. Areas of oil slick accumulations were identified, delineated, georeferenced, measured and mapped to a common scale using both manual and digital techniques. A Gaussian mathematical model was employed to provide quantitative estimates of surface oil accumulations identified within each image over the entire twenty year period. This study indicates that variances in mapped oil slick location and extent as well as the estimated amounts of oil present within each image may be attributed to image type and quality as well as environmental conditions.

  12. Remote sensing study of historical changes in natural oil slick volumes in the Santa Barbara Channel

    Energy Technology Data Exchange (ETDEWEB)

    Scepan, J.; Estes, J.; Hornafius, J.S. [Univ. of California, Santa Barbara, CA (United States)

    1996-12-31

    Large natural oil slicks are continually forming in the Santa Barbara Channel as a result of natural hydrocarbon seeps that occur above subsurface oil accumulations. Evaporation of volatile constituents in these oil slicks is a significant source of air pollution. In this study we employed a suite of remote sensing data along with a variety of image processing and geographic information system techniques to analyze the location, extent and changes in sea surface oil slicks during the period of 1975 - present. An extensive collection of airborne and spaceborne remote sensor data was accessed and examined for this study, including aerial photography, airborne spectral and microwave data, Landsat MSS and TM data and Shuttle Imaging Radar. Areas of oil slick accumulations were identified, delineated, georeferenced, measured and mapped to a common scale using both manual and digital techniques. A Gaussian mathematical model was employed to provide quantitative estimates of surface oil accumulations identified within each image over the entire twenty year period. This study indicates that variances in mapped oil slick location and extent as well as the estimated amounts of oil present within each image may be attributed to image type and quality as well as environmental conditions.

  13. Comparison and Analysis of the Control Power Between Two Different Perfect Controlled Teleportation Schemes Using Four-particle Cluster State

    Science.gov (United States)

    Jiang, Yu-ting; Mo, Zhi-wen

    2017-10-01

    Control power is used to discuss about the controller's measurable authority. It's a new index to describe the controlled teleportation schemes from the point of view of the controller. In this paper, we introduce two perfect controlled teleportation schemes and calculate the control power under different control particles. In scheme 1, the controller just controls one particle, which is particle 2. And in scheme 2, the controller controls the particles 2 and 3. They both use the cluster state |ψ > _{1234}={1/2}(|0000> +|0011> +|1100> -|1111> )_{1234} as communication channel. By calculating the control power between two schemes, the control power of scheme 1 is 1/3, which is the minimal value of control power. On the contrary, the control power of scheme 2 is maximal, 1/2. Scheme 2 which controls two particles successfully promotes the control power comparing with scheme 1. It's evidently that controlling particle 2 is a necessary condition. And controlling particle 3 can gain the control power but the controller cannot control it solely.

  14. Comparisons of clustered regularly interspaced short palindromic repeats and viromes in human saliva reveal bacterial adaptations to salivary viruses.

    Science.gov (United States)

    Pride, David T; Salzman, Julia; Relman, David A

    2012-09-01

    Explorations of human microbiota have provided substantial insight into microbial community composition; however, little is known about interactions between various microbial components in human ecosystems. In response to the powerful impact of viral predation, bacteria have acquired potent defences, including an adaptive immune response based on the clustered regularly interspaced short palindromic repeats (CRISPRs)/Cas system. To improve our understanding of the interactions between bacteria and their viruses in humans, we analysed 13 977 streptococcal CRISPR sequences and compared them with 2 588 172 virome reads in the saliva of four human subjects over 17 months. We found a diverse array of viruses and CRISPR spacers, many of which were specific to each subject and time point. There were numerous viral sequences matching CRISPR spacers; these matches were highly specific for salivary viruses. We determined that spacers and viruses coexist at the same time, which suggests that streptococcal CRISPR/Cas systems are under constant pressure from salivary viruses. CRISPRs in some subjects were just as likely to match viral sequences from other subjects as they were to match viruses from the same subject. Because interactions between bacteria and viruses help to determine the structure of bacterial communities, CRISPR-virus analyses are likely to provide insight into the forces shaping the human microbiome. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  15. WIYN open cluster study. LXII. Comparison of isochrone systems using deep multi-band photometry of M35

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, B.; Frinchaboy, P. [Texas Christian University, Fort Worth, TX 76129 (United States); Kinemuchi, K. [Apache Point Observatory, Sunspot, NM 88349 (United States); Sarajedini, A. [University of Florida, Gainesville, FL 32611 (United States); Cohen, R., E-mail: b.a.thompson1@tcu.edu [Universidad de Concepcion, Concepcion (Chile)

    2014-11-01

    The current generation of stellar isochrone models exhibits non-negligible discrepancies due to variations in the input physics. The success of each model is determined by how well it fits the observations, and this paper aims to disentangle contributions from the various physical inputs. New deep, wide-field optical and near-infrared photometry (UBVRIJHK{sub S} ) of the cluster M35 is presented, against which several isochrone systems are compared: Padova, PARSEC, Dartmouth, and Y {sup 2}. Two different atmosphere models are applied to each isochrone: ATLAS9 and BT-Settl. For any isochrone set and atmosphere model, observed data are accurately reproduced for all stars more massive than 0.7 M {sub ☉}. For stars less massive than 0.7 M {sub ☉}, Padova and PARSEC isochrones consistently produce higher temperatures than observed. Dartmouth and Y{sup 2} isochrones with BT-Settl atmospheres reproduce optical data accurately; however, they appear too blue in IR colors. It is speculated that molecular contributions to stellar spectra in the near-infrared may not be fully explored, and that future study may reconcile these differences.

  16. Evaluating patterns of a white-band disease (WBD outbreak in Acropora palmata using spatial analysis: a comparison of transect and colony clustering.

    Directory of Open Access Journals (Sweden)

    Jennifer A Lentz

    Full Text Available BACKGROUND: Despite being one of the first documented, there is little known of the causative agent or environmental stressors that promote white-band disease (WBD, a major disease of Caribbean Acropora palmata. Likewise, there is little known about the spatiality of outbreaks. We examined the spatial patterns of WBD during a 2004 outbreak at Buck Island Reef National Monument in the US Virgin Islands. METHODOLOGY/PRINCIPAL FINDINGS: Ripley's K statistic was used to measure spatial dependence of WBD across scales. Localized clusters of WBD were identified using the DMAP spatial filtering technique. Statistics were calculated for colony- (number of A. palmata colonies with and without WBD within each transect and transect-level (presence/absence of WBD within transects data to evaluate differences in spatial patterns at each resolution of coral sampling. The Ripley's K plots suggest WBD does cluster within the study area, and approached statistical significance (p = 0.1 at spatial scales of 1100 m or less. Comparisons of DMAP results suggest the transect-level overestimated the prevalence and spatial extent of the outbreak. In contrast, more realistic prevalence estimates and spatial patterns were found by weighting each transect by the number of individual A. palmata colonies with and without WBD. CONCLUSIONS: As the search for causation continues, surveillance and proper documentation of the spatial patterns may inform etiology, and at the same time assist reef managers in allocating resources to tracking the disease. Our results indicate that the spatial scale of data collected can drastically affect the calculation of prevalence and spatial distribution of WBD outbreaks. Specifically, we illustrate that higher resolution sampling resulted in more realistic disease estimates. This should assist in selecting appropriate sampling designs for future outbreak investigations. The spatial techniques used here can be used to facilitate other

  17. Evaluating patterns of a white-band disease (WBD) outbreak in Acropora palmata using spatial analysis: a comparison of transect and colony clustering.

    Science.gov (United States)

    Lentz, Jennifer A; Blackburn, Jason K; Curtis, Andrew J

    2011-01-01

    Despite being one of the first documented, there is little known of the causative agent or environmental stressors that promote white-band disease (WBD), a major disease of Caribbean Acropora palmata. Likewise, there is little known about the spatiality of outbreaks. We examined the spatial patterns of WBD during a 2004 outbreak at Buck Island Reef National Monument in the US Virgin Islands. Ripley's K statistic was used to measure spatial dependence of WBD across scales. Localized clusters of WBD were identified using the DMAP spatial filtering technique. Statistics were calculated for colony- (number of A. palmata colonies with and without WBD within each transect) and transect-level (presence/absence of WBD within transects) data to evaluate differences in spatial patterns at each resolution of coral sampling. The Ripley's K plots suggest WBD does cluster within the study area, and approached statistical significance (p = 0.1) at spatial scales of 1100 m or less. Comparisons of DMAP results suggest the transect-level overestimated the prevalence and spatial extent of the outbreak. In contrast, more realistic prevalence estimates and spatial patterns were found by weighting each transect by the number of individual A. palmata colonies with and without WBD. As the search for causation continues, surveillance and proper documentation of the spatial patterns may inform etiology, and at the same time assist reef managers in allocating resources to tracking the disease. Our results indicate that the spatial scale of data collected can drastically affect the calculation of prevalence and spatial distribution of WBD outbreaks. Specifically, we illustrate that higher resolution sampling resulted in more realistic disease estimates. This should assist in selecting appropriate sampling designs for future outbreak investigations. The spatial techniques used here can be used to facilitate other coral disease studies, as well as, improve reef conservation and management.

  18. Quantitative comparison of clustered microcalcifications in for-presentation and for-processing mammograms in full-field digital mammography.

    Science.gov (United States)

    Wang, Juan; Nishikawa, Robert M; Yang, Yongyi

    2017-07-01

    Mammograms acquired with full-field digital mammography (FFDM) systems are provided in both "for-processing'' and "for-presentation'' image formats. For-presentation images are traditionally intended for visual assessment by the radiologists. In this study, we investigate the feasibility of using for-presentation images in computerized analysis and diagnosis of microcalcification (MC) lesions. We make use of a set of 188 matched mammogram image pairs of MC lesions from 95 cases (biopsy proven), in which both for-presentation and for-processing images are provided for each lesion. We then analyze and characterize the MC lesions from for-presentation images and compare them with their counterparts in for-processing images. Specifically, we consider three important aspects in computer-aided diagnosis (CAD) of MC lesions. First, we quantify each MC lesion with a set of 10 image features of clustered MCs and 12 textural features of the lesion area. Second, we assess the detectability of individual MCs in each lesion from the for-presentation images by a commonly used difference-of-Gaussians (DoG) detector. Finally, we study the diagnostic accuracy in discriminating between benign and malignant MC lesions from the for-presentation images by a pretrained support vector machine (SVM) classifier. To accommodate the underlying background suppression and image enhancement in for-presentation images, a normalization procedure is applied. The quantitative image features of MC lesions from for-presentation images are highly consistent with that from for-processing images. The values of Pearson's correlation coefficient between features from the two formats range from 0.824 to 0.961 for the 10 MC image features, and from 0.871 to 0.963 for the 12 textural features. In detection of individual MCs, the FROC curve from for-presentation is similar to that from for-processing. In particular, at sensitivity level of 80%, the average number of false-positives (FPs) per image region is 9

  19. Coccolithophore response to climate and surface hydrography in Santa Barbara Basin, California, AD 1917–2004

    Directory of Open Access Journals (Sweden)

    M. Grelaud

    2009-10-01

    Full Text Available The varved sedimentary AD 1917–2004 record from the depositional center of the Santa Barbara Basin (SBB, California was analyzed with monthly to triannual resolution to yield relative abundances of six coccolithophore species representing at least 96% of the coccolithophore assemblage. Seasonal/annual relative abundances respond to climatic and surface hydrographic conditions in the SBB, whereby (i the three species G. oceanica, H. carteri and F. profunda are characteristic of the strength of the northward flowing warm California Counter Current, (ii the two species G. ericsonii and G. muellerae are associated with the cold equatorward flowing California Current, (iii and E. huxleyi appears to be endemic to the SBB. Spectral analyses on relative abundances of these species show that all are influenced by the El Niño Southern Oscillation (ENSO and/or by the Pacific Decadal Oscillation (PDO. Increased relative abundances of G. oceanica and H. carteri are associated with warm ENSO events, G. muellerae responds to warm PDO events and the abundance of G. ericsonii increases during cold PDO events. Morphometric parameters measured on E. huxleyi, G. muellerae and G. oceanica indicate increasing coccolithophore shell carbonate mass from ~1917 until 2004 concomitant with rising pCO2 and sea surface temperature in the region of the SBB.

  20. Local Management of National Cluster Policies: Comparative Case Studies of Japanese, German, and French Biotechnology Clusters

    Directory of Open Access Journals (Sweden)

    Hiroyuki Okamuro

    2015-11-01

    Full Text Available Cluster policies have attracted increasing attention worldwide, but only a few studies have focused on their management by local cluster organizations. We investigate the relationship between national cluster policies and their management by local cluster organizations from a comparative perspective. For this purpose, we provide a detailed comparison of national cluster policies in Japan, Germany, and France as well as six prominent biotechnology clusters in these countries. Information on the focal clusters and on the management of cluster policies was obtained using semi-structured interviews with cluster managers. We find that national cluster policies considerably differ among these countries according to basic conditions of clusters and that the patterns of national cluster policy are closely related to those of local cluster management, despite some differences between clusters in the same country caused by various regional characteristics.

  1. Acceleration of Magnetospheric Relativistic Electrons by Ultra-Low Frequency Waves: A Comparison between Two Cases Observed by Cluster and LANL Satellites

    Science.gov (United States)

    Shao, X.; Fung, S. F.; Tan, L. C.; Sharma, A. S.

    2010-01-01

    Understanding the origin and acceleration of magnetospheric relativistic electrons (MREs) in the Earth's radiation belt during geomagnetic storms is an important subject and yet one of outstanding questions in space physics. It has been statistically suggested that during geomagnetic storms, ultra-low-frequency (ULF) Pc-5 wave activities in the magnetosphere are correlated with order of magnitude increase of MRE fluxes in the outer radiation belt. Yet, physical and observational understandings of resonant interactions between ULF waves and MREs remain minimum. In this paper, we show two events during storms on September 25, 2001 and November 25, 2001, the solar wind speeds in both cases were > 500 km/s while Cluster observations indicate presence of strong ULF waves in the magnetosphere at noon and dusk, respectively, during a approx. 3-hour period. MRE observations by the Los Alamos (LANL) spacecraft show a quadrupling of 1.1-1.5 MeV electron fluxes in the September 25, 2001 event, but only a negligible increase in the November 2.5, 2001 event. We present a detailed comparison between these two events. Our results suggest that the effectiveness of MRE acceleration during the September 25, 2001 event can be attributed to the compressional wave mode with strong ULF wave activities and the physical origin of MRE acceleration depends more on the distribution of toroidal and poloidal ULF waves in the outer radiation belt.

  2. Cluster Headache

    Science.gov (United States)

    ... re at risk of cluster headache. A family history. Having a parent or sibling who has had cluster headache might ... of Nondiscrimination Advertising Mayo Clinic is a not-for-profit organization ...

  3. Meaningful Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Sanfilippo, Antonio P.; Calapristi, Augustin J.; Crow, Vernon L.; Hetzler, Elizabeth G.; Turner, Alan E.

    2004-05-26

    We present an approach to the disambiguation of cluster labels that capitalizes on the notion of semantic similarity to assign WordNet senses to cluster labels. The approach provides interesting insights on how document clustering can provide the basis for developing a novel approach to word sense disambiguation.

  4. Sedimentary pyrite δ^(34)S differs from porewater sulfide in Santa Barbara Basin: proposed role of organic sulfur

    OpenAIRE

    Raven, Morgan Reed; Sessions, Alex L.; Fischer, Woodward W.; Adkins, Jess F.

    2016-01-01

    Santa Barbara Basin sediments host a complex network of abiotic and metabolic chemical reactions that knit together the carbon, sulfur, and iron cycles. From a 2.1-m sediment core collected in the center of the basin, we present high-resolution profiles of the concentrations and isotopic compositions of all the major species in this system: sulfate, sulfide (∑H_2S), elemental sulfur (S^0), pyrite, extractable organic sulfur (OS), proto-kerogen S, total organic and dissolved inorganic carbon, ...

  5. Moralidade, autonomia e educação em Kant : uma leitura a partir de Barbara Herman

    OpenAIRE

    Fábio C. Ribeiro Mendes

    2013-01-01

    A educação é um tema geralmente considerado periférico à teoria moral de Kant. A presente pesquisa pretende apontar para a possibilidade não usual de uma leitura da filosofia moral kantiana, a partir das contribuições de Barbara Herman. Defende-se que é possível adotar a perspectiva da formação moral do agente concreto como uma maneira de compreender uma importante conexão entre os conceitos de moralidade, autonomia e educação. O primeiro passo é observar que a discussão em torno do valor do ...

  6. Sources and Pathways of Bacterial Contamination in Urban Streams and Ocean Beaches, Santa Barbara, California

    Science.gov (United States)

    Johnson, R. D.; Mendez, G. O.; La, J. X.; Izbicki, J. A.

    2005-12-01

    Streams and ocean beaches in Santa Barbara, California, occasionally have concentrations of fecal indicator bacteria that exceed public health standards for recreational water, forcing temporary beach closures. Possible sources of fecal bacteria contamination include transient human populations, animal populations, and leaking sewer lines. The purpose of this three-year study is to identify important sources of fecal bacteria affecting the urban streams and beaches and to identify important pathways of transport. Contamination may enter streams and beaches directly by surface runoff, but also may be transmitted short distances through shallow ground water. Our analysis of existing historical data shows that fecal indicator bacteria concentrations are higher in near-shore ocean water following extreme high tides. The possible role of near shore ground water in supplying contaminants to the sea will be investigated by sampling water from an array of shallow wells installed for this study between an older city sewer line and the ocean. The ground water flux to the ocean will be inferred from water levels in these wells, and further tested by radium isotope values in near shore ocean samples. Two additional well arrays will be installed to test for leakage from residential sewage hookups and measure associated exchanges between ground water, streams, and ocean. Preliminary data collected by this study show fecal indicator bacteria concentrations in urban reaches of Mission Creek and its tributaries, the principle drainage through the city, are higher during low flow periods than during periods of higher flow. Analysis of preliminary data also shows short-term temporal variations in bacterial concentrations during twenty-four hour periods. Human enterovirus has been detected in our sample from one urban-drain tributary to Mission Creek. In order to identify the origins of fecal indicator bacteria water samples from Mission Creek, its tributaries, urban drains, and

  7. The würmian mammalian fauna of Grotta Barbara (Monte Circeo: palaeoeconomical and environment conditions data / La mammalofauna würmiana di Grotta Barbara (Monte Circeo: implicazioni paleoeconomiche e paleoambientali

    Directory of Open Access Journals (Sweden)

    Lucia Caloi

    1989-07-01

    Full Text Available Abstract A fossil fauna composed predominantly by red deer, and also containing fallow-deer and steinbock was examined. It comes from late-Mousterian levels at Grotta Barbara, and is correlated with the first moderately cold oscillations of palaeotemperature stage 3. The analysis of the remains suggests that: a among cervids, young and females were preferentially hunted; b butchering was performed mainly in the cave; c the bones were crushed in order to extract the marrow and, less frequently, the fat. Riassunto Viene esaminata una fauna a cervo dominante, daino e stambecco, proveniente dai livelli a industria tardo-musteriana di Grotta Barbara. L'associazione viene riferita alle prime oscillazioni moderatamente fredde dello stadio 3 della scala isotopica. L'analisi dei resti consente di ipotizzare che: a la caccia era rivolta in prevalenza a femmine giovani; b la macellazione avveniva prevalentemente in grotta; c le ossa erano frantumate al fine di estrarne il midollo e, meno frequentemente, il grasso.

  8. Charged FeC{sub n} clusters: A comparison with TMC{sub n}{sup +}/TMC{sub n}{sup -} (TM = Sc, Ti, V, Co and Zn, n = 1-8) systems

    Energy Technology Data Exchange (ETDEWEB)

    Redondo, Pilar, E-mail: predondo@qf.uva.es [Computacional Chemistry Group, Departamento de Quimica Fisica y Quimica Inorganica, Facultad de Ciencias, Universidad de Valladolid, 47005 Valladolid (Spain); Largo, Laura; Barrientos, Carmen [Computacional Chemistry Group, Departamento de Quimica Fisica y Quimica Inorganica, Facultad de Ciencias, Universidad de Valladolid, 47005 Valladolid (Spain)

    2009-10-16

    The electronic and geometrical structures of the ground and excited states for the linear, fan and cyclic isomers of FeC{sub n}{sup +}andFeC{sub n}{sup -} (n = 1-8) compounds are calculated using the B3LYP method. A comparison of these results with the previously obtained for TMC{sub n}{sup +}/TMC{sub n}{sup -} (TM = Sc, Ti, V, Co and Zn) systems, is carried out. Quartet and sextet states are found the most stables for FeC{sub n}{sup +} clusters. Linear FeC{sub n}{sup -} clusters prefer doublet and quartet ground states, whereas for cyclic and fan isomers the most stables are quartet and sextet ones. n-odd linear, fan, and cyclic FeC{sub n}{sup +} isomers are more stable than adjacent n-even ones. For FeC{sub n}{sup -} clusters the opposite trend is found for linear and fan structures, whereas for cyclic isomers the relative stability decreases along the series. In general linear isomers are the most stable conformations for FeC{sub n}{sup +}/FeC{sub n}{sup -} clusters. Systematic trends of different properties are analyzed for TMC{sub n}{sup +}/TMC{sub n}{sup -} clusters.

  9. Data Clustering

    Science.gov (United States)

    Wagstaff, Kiri L.

    2012-03-01

    On obtaining a new data set, the researcher is immediately faced with the challenge of obtaining a high-level understanding from the observations. What does a typical item look like? What are the dominant trends? How many distinct groups are included in the data set, and how is each one characterized? Which observable values are common, and which rarely occur? Which items stand out as anomalies or outliers from the rest of the data? This challenge is exacerbated by the steady growth in data set size [11] as new instruments push into new frontiers of parameter space, via improvements in temporal, spatial, and spectral resolution, or by the desire to "fuse" observations from different modalities and instruments into a larger-picture understanding of the same underlying phenomenon. Data clustering algorithms provide a variety of solutions for this task. They can generate summaries, locate outliers, compress data, identify dense or sparse regions of feature space, and build data models. It is useful to note up front that "clusters" in this context refer to groups of items within some descriptive feature space, not (necessarily) to "galaxy clusters" which are dense regions in physical space. The goal of this chapter is to survey a variety of data clustering methods, with an eye toward their applicability to astronomical data analysis. In addition to improving the individual researcher’s understanding of a given data set, clustering has led directly to scientific advances, such as the discovery of new subclasses of stars [14] and gamma-ray bursts (GRBs) [38]. All clustering algorithms seek to identify groups within a data set that reflect some observed, quantifiable structure. Clustering is traditionally an unsupervised approach to data analysis, in the sense that it operates without any direct guidance about which items should be assigned to which clusters. There has been a recent trend in the clustering literature toward supporting semisupervised or constrained

  10. Monitoring the content of fluorine, lead and cadmium in water for human consumption in a sector of Santa Barbara of Heredia

    International Nuclear Information System (INIS)

    Arias Sanchez, Federico; Alvarado, A.L.

    2000-01-01

    Samples of drinking water from natural sources and distribution tanks in a specific area of Santa Barbara of Heredia were analyzed. The content of fluorine, lead and cadmium was determined applying the Spans method and Anodic Stripping Voltamperometry respectively, over a period of nine months. During July 1994 to February 1995, levels of lead, cadmium and fluoride in the samples, remained under the permissible limits according to the Norma Nacional para la Calidad del Agua Potable, and therefore do not represent a toxicological danger to the population of Santa Barbara of Heredia. (author) [es

  11. Foramgeographical affinities of the west and east coasts of India: An approach through cluster analysis and comparison of taxonomical, environmental and ecological parameters of Recent foraminiferal thanatotopes

    Digital Repository Service at National Institute of Oceanography (India)

    Katha, P.K.; Bhalla, S.N.; Nigam, R.

    realms as their assemblages form two separate 'clusters' with only 0.1 level of 'Degree of Association' amongst them. The pattern of clusters shows two faunal assemblages namely- 'Inner' and 'Outer East Marginal Assemblage of Arabian Sea' along the West...

  12. A Comparison Of X-ray, Radio, And Lensing Results With GBT+MUSTANG Observations Of The Sunyaev-Zel'dovich Effect In Galaxy Clusters

    Science.gov (United States)

    Mroczkowski, Tony; Devlin, M.; Dicker, S.; Korngut, P.; Mason, B.; Reese, E.; Romero, C.; Sarazin, C.; Sun, M.; Young, A.; Lensing, Cluster; survey with Hubble, Supernova

    2012-05-01

    We present recent high angular resolution (9") Sunyaev-Zel'dovich effect (SZE) observations with MUSTANG, a 90-GHz bolometric receiver on the 100-meter Green Bank Telescope (GBT). MUSTANG is now imaging a sample of clusters with complementary Chandra X-ray observations, HST optical observations that probe the mass distribution through strong and weak lensing, radio observations that probe the non-thermal component of the intra-cluster gas, and lower resolution SZE observations that can recover larger scales (>1'). The MUSTANG observations, which will be used to assess the impact of substructure on SZE scaling relations, are some of the highest resolution SZE images to date, and are revealing complex pressure substructures in intermediate redshift clusters. Combined, these observations reveal complicated cluster dynamics, which must be understood in order to use clusters as cosmological probes.

  13. A comparison of hierarchical cluster analysis and league table rankings as methods for analysis and presentation of district health system performance data in Uganda.

    Science.gov (United States)

    Tashobya, Christine K; Dubourg, Dominique; Ssengooba, Freddie; Speybroeck, Niko; Macq, Jean; Criel, Bart

    2016-03-01

    In 2003, the Uganda Ministry of Health introduced the district league table for district health system performance assessment. The league table presents district performance against a number of input, process and output indicators and a composite index to rank districts. This study explores the use of hierarchical cluster analysis for analysing and presenting district health systems performance data and compares this approach with the use of the league table in Uganda. Ministry of Health and district plans and reports, and published documents were used to provide information on the development and utilization of the Uganda district league table. Quantitative data were accessed from the Ministry of Health databases. Statistical analysis using SPSS version 20 and hierarchical cluster analysis, utilizing Wards' method was used. The hierarchical cluster analysis was conducted on the basis of seven clusters determined for each year from 2003 to 2010, ranging from a cluster of good through moderate-to-poor performers. The characteristics and membership of clusters varied from year to year and were determined by the identity and magnitude of performance of the individual variables. Criticisms of the league table include: perceived unfairness, as it did not take into consideration district peculiarities; and being oversummarized and not adequately informative. Clustering organizes the many data points into clusters of similar entities according to an agreed set of indicators and can provide the beginning point for identifying factors behind the observed performance of districts. Although league table ranking emphasize summation and external control, clustering has the potential to encourage a formative, learning approach. More research is required to shed more light on factors behind observed performance of the different clusters. Other countries especially low-income countries that share many similarities with Uganda can learn from these experiences. © The Author 2015

  14. Density functional study on size-dependent structures, stabilities, electronic and magnetic properties of Au(n)M (M = Al and Si, n = 1-9) clusters: comparison with pure gold clusters.

    Science.gov (United States)

    Li, Yan-Fang; Mao, Ai-Jie; Li, Yang; Kuang, Xiao-Yu

    2012-07-01

    The density functional theory (DFT) method has been employed to systematically investigate the geometrical structures, relative stabilities, and electronic and magnetic properties of Au(n)M (M = Al and Si, n = 1-9) clusters for clarifying the effect of Al(Si) modulation on the gold nanostructures. Of all the clusters studied, the most stable configurations adopt a three-dimensional structure for Au(n)Al at n = 4-8 and Au(n)Si at n = 3-9, while for pure gold systems, no three-dimensional lowest energy structures are obtained. Through a careful analysis of the fragmentation energy, second-order difference of energy, HOMO-LUMO energy gap, and magnetic moment as a function of cluster size, an odd-even alternative phenomenon has been observed. The results show that the clusters with even-number valence electrons have a higher relative stability, but lower magnetic moments. Furthermore, Al(Si) doping is found to enhance the stabilities of gold frameworks. In addition, the charge analysis has been given to understand the different effects of individual doped atom on electronic properties and compared further.

  15. Weighted Clustering

    DEFF Research Database (Denmark)

    Ackerman, Margareta; Ben-David, Shai; Branzei, Simina

    2012-01-01

    the partitional and hierarchical settings, characterizing the conditions under which algorithms react to weights. Extending a recent framework for clustering algorithm selection, we propose intuitive properties that would allow users to choose between clustering algorithms in the weighted setting and classify...

  16. Cluster editing

    DEFF Research Database (Denmark)

    Böcker, S.; Baumbach, Jan

    2013-01-01

    . The problem has been the inspiration for numerous algorithms in bioinformatics, aiming at clustering entities such as genes, proteins, phenotypes, or patients. In this paper, we review exact and heuristic methods that have been proposed for the Cluster Editing problem, and also applications...

  17. Computer-aided detection system for clustered microcalcifications: comparison of performance on full-field digital mammograms and digitized screen-film mammograms

    International Nuclear Information System (INIS)

    Ge Jun; Hadjiiski, Lubomir M; Sahiner, Berkman; Wei Jun; Helvie, Mark A; Zhou Chuan; Chan Heangping

    2007-01-01

    We have developed a computer-aided detection (CAD) system to detect clustered microcalcifications automatically on full-field digital mammograms (FFDMs) and a CAD system for screen-film mammograms (SFMs). The two systems used the same computer vision algorithms but their false positive (FP) classifiers were trained separately with sample images of each modality. In this study, we compared the performance of the CAD systems for detection of clustered microcalcifications on pairs of FFDM and SFM obtained from the same patient. For case-based performance evaluation, the FFDM CAD system achieved detection sensitivities of 70%, 80% and 90% at an average FP cluster rate of 0.07, 0.16 and 0.63 per image, compared with an average FP cluster rate of 0.15, 0.38 and 2.02 per image for the SFM CAD system. The difference was statistically significant with the alternative free-response receiver operating characteristic (AFROC) analysis. When evaluated on data sets negative for microcalcification clusters, the average FP cluster rates of the FFDM CAD system were 0.04, 0.11 and 0.33 per image at detection sensitivity level of 70%, 80% and 90% compared with an average FP cluster rate of 0.08, 0.14 and 0.50 per image for the SFM CAD system. When evaluated for malignant cases only, the difference of the performance of the two CAD systems was not statistically significant with AFROC analysis

  18. Cluster-based upper body marker models for three-dimensional kinematic analysis: Comparison with an anatomical model and reliability analysis.

    Science.gov (United States)

    Boser, Quinn A; Valevicius, Aïda M; Lavoie, Ewen B; Chapman, Craig S; Pilarski, Patrick M; Hebert, Jacqueline S; Vette, Albert H

    2018-02-27

    Quantifying angular joint kinematics of the upper body is a useful method for assessing upper limb function. Joint angles are commonly obtained via motion capture, tracking markers placed on anatomical landmarks. This method is associated with limitations including administrative burden, soft tissue artifacts, and intra- and inter-tester variability. An alternative method involves the tracking of rigid marker clusters affixed to body segments, calibrated relative to anatomical landmarks or known joint angles. The accuracy and reliability of applying this cluster method to the upper body has, however, not been comprehensively explored. Our objective was to compare three different upper body cluster models with an anatomical model, with respect to joint angles and reliability. Non-disabled participants performed two standardized functional upper limb tasks with anatomical and cluster markers applied concurrently. Joint angle curves obtained via the marker clusters with three different calibration methods were compared to those from an anatomical model, and between-session reliability was assessed for all models. The cluster models produced joint angle curves which were comparable to and highly correlated with those from the anatomical model, but exhibited notable offsets and differences in sensitivity for some degrees of freedom. Between-session reliability was comparable between all models, and good for most degrees of freedom. Overall, the cluster models produced reliable joint angles that, however, cannot be used interchangeably with anatomical model outputs to calculate kinematic metrics. Cluster models appear to be an adequate, and possibly advantageous alternative to anatomical models when the objective is to assess trends in movement behavior. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Analysis and Comparison of Interdisciplinary Relations of Library Science and Information Science Based on Citation Clustering in The Period of Before and After the Appearance of the Web

    Directory of Open Access Journals (Sweden)

    Farideh Osareh

    2016-06-01

    Full Text Available The purpose of the present study was to analyze the interdisciplinary relations of “Library Science and Information Science”. For this purpose the subject categories of citing and cited journals of these fields were investigated in JCR database during the period of 1987-1997 and 2003-2013, and through the comparsion of obtained results the impact of information technology on the development of “LIS” interdisciplinarity was investigated. Methedology of the research was co-citation analysis of journals in scientometrics studies. Also the research was performed using the conventional techniques of scientometrics including Bradford law, Ward hierarchical clustering approach in statistical software SPSS, and the new measure including Proximity index. Research community includes citing and cited journals of 56 “LIS” journals during 1987-1997 and 83 journals during 2003-2013 in Journals Ctiation Report (JCR database. The results showed that “LIS” has been influenced by other subject categories more than affecting them. For example, the number of journals which “LIS” cited from 1758 (in the first period has increased to 5303 (in the second period. Co-occurrence matrix of core citing and cited subject categories was analyzed, and three main clusters in the first period and seven clusters in the second period were drawn. In general, the amount and quality of co-occurrence of subject categories in clusters showed that the domain and variety of affecting and affected subject categories were expanded in the second period. Structural similarity of clusters for affecting and affected subject categories calculated. Results showed that structural similarity of clusters in the second period was %10 higher than in the first period. Also, the Structural similarity of affecting clusters of “LIS” was more than affected clusters. Assessment of difference between subject categories groups by ANOVA and Tukey Post hoc tests showed that there were

  20. Clustering Dycom

    KAUST Repository

    Minku, Leandro L.

    2017-10-06

    Background: Software Effort Estimation (SEE) can be formulated as an online learning problem, where new projects are completed over time and may become available for training. In this scenario, a Cross-Company (CC) SEE approach called Dycom can drastically reduce the number of Within-Company (WC) projects needed for training, saving the high cost of collecting such training projects. However, Dycom relies on splitting CC projects into different subsets in order to create its CC models. Such splitting can have a significant impact on Dycom\\'s predictive performance. Aims: This paper investigates whether clustering methods can be used to help finding good CC splits for Dycom. Method: Dycom is extended to use clustering methods for creating the CC subsets. Three different clustering methods are investigated, namely Hierarchical Clustering, K-Means, and Expectation-Maximisation. Clustering Dycom is compared against the original Dycom with CC subsets of different sizes, based on four SEE databases. A baseline WC model is also included in the analysis. Results: Clustering Dycom with K-Means can potentially help to split the CC projects, managing to achieve similar or better predictive performance than Dycom. However, K-Means still requires the number of CC subsets to be pre-defined, and a poor choice can negatively affect predictive performance. EM enables Dycom to automatically set the number of CC subsets while still maintaining or improving predictive performance with respect to the baseline WC model. Clustering Dycom with Hierarchical Clustering did not offer significant advantage in terms of predictive performance. Conclusion: Clustering methods can be an effective way to automatically generate Dycom\\'s CC subsets.

  1. Comparison of the periodic slab approach with the finite cluster description of metal-organic interfaces at the example of PTCDA on Ag(110).

    Science.gov (United States)

    Banerjee, Jaita; Behnle, Stefan; Galbraith, Martin C E; Settels, Volker; Engels, Bernd; Tonner, Ralf; Fink, Reinhold F

    2018-02-05

    We present a comparative study of metal-organic interface properties obtained from dispersion corrected density functional theory calculations based on two different approaches: the periodic slab-supercell technique and cluster models with 32-290 Ag atoms. Fermi smearing and fixing of cluster borders are required to make the cluster calculation feasible and realistic. The considered adsorption structure and energy of a PTCDA molecule on the Ag(110) surface is not well reproduced with clusters containing only two metallic layers. However, all clusters with four layers of silver atoms and sufficient lateral extension reproduce the adsorbate structure within 0.04 Å with respect to the slab-supercell structure and provide adsorption energies of ( -4.45± 0.08 eV) consistent with the slab result of -4.47 eV. Thus, metal-organic adsorbate systems can be realistically represented by properly defined cluster models. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  2. Automated compilation of pseudo-lithology maps from geophysical data sets: a comparison of Gustafson-Kessel and fuzzy c-means cluster algorithms

    Science.gov (United States)

    Paasche, Hendrik; Eberle, Detlef

    2011-11-01

    The fuzzy partitioning Gustafson-Kessel cluster algorithm is employed for rapid and objective integration of multi-parameter Earth-science related databases. We begin by evaluating the Gustafson-Kessel algorithm using the example of a synthetic study and compare the results to those obtained from the more widely employed fuzzy c-means algorithm. Since the Gustafson-Kessel algorithm goes beyond the potential of the fuzzy c-means algorithm by adapting the shape of the clusters to be detected and enabling a manual control of the cluster volume, we believe the results obtained from Gustafson-Kessel algorithm to be superior. Accordingly, a field database comprising airborne and ground-based geophysical data sets is analysed, which has previously been classified by means of the fuzzy c-means algorithm. This database is integrated using the Gustafson-Kessel algorithm thus minimising the amount of empirical data processing required before and after fuzzy c-means clustering. The resultant zonal geophysical map is more evenly clustered matching regional geology information available from the survey area. Even additional information about linear structures, e.g. as typically caused by the presence of dolerite dykes or faults, is visible in the zonal map obtained from Gustafson-Kessel cluster analysis.

  3. Probing the structural and electronic properties of small vanadium dioxide clusters by density functional theory and comparison with experimental photoelectron spectroscopy

    Science.gov (United States)

    Wang, Huai-Qian; Li, Hui-Fang

    2012-10-01

    The structural evolution and bonding of a series of early transition-metal dioxide clusters, {V_n O}_2^q (n = 3-9, q = 0, -1), have been investigated using density functional theory (DFT) calculations and the results are compared with experimental literature data. For each vanadium dioxide cluster, many low-lying isomers are generated using the Saunders "Kick" global minimum stochastic search method. Theoretical electron detachment energies (both vertical and adiabatic) were compared with the experimental measurements to verify the ground states of the vanadium dioxide clusters obtained from the DFT calculations. Five kinds of dissociative adsorption configurations of ground-state structure of {V_n O}_2^q are identified. The dissociative adsorption of O2 on Vn-1, 0 is more favorable than O2 molecular adsorption. Furthermore, the adsorption energy of O2 is higher than that of a single atom on the bare Vn-1, 0 clusters, but less than twice the adsorption energy for an atom, indicating that O2 being adsorbed on vanadium clusters are more difficult than single O atom adsorbed on vanadium clusters.

  4. Evaluation of Ocean Color Scanner (OCS) photographic and digital data: Santa Barbara Channel test site, 29 October 1975 overflight

    Science.gov (United States)

    Kraus, S. P.; Estes, J. E.; Kronenberg, M. R.; Hajic, E. J.

    1977-01-01

    A summary of Ocean Color Scanner data was examined to evaluate detection and discrimination capabilities of the system for marine resources, oil pollution and man-made sea surface targets of opportunity in the Santa Barbara Channel. Assessment of the utility of OCS for the determination of sediment transport patterns along the coastal zone was a secondary goal. Data products provided 1975 overflight were in digital and analog formats. In evaluating the OCS data, automated and manual procedures were employed. A total of four channels of data in digital format were analyzed, as well as three channels of color combined imagery, and four channels of black and white imagery. In addition, 1:120,000 scale color infrared imagery acquired simultaneously with the OCS data were provided for comparative analysis purposes.

  5. Clustering analysis

    International Nuclear Information System (INIS)

    Romli

    1997-01-01

    Cluster analysis is the name of group of multivariate techniques whose principal purpose is to distinguish similar entities from the characteristics they process.To study this analysis, there are several algorithms that can be used. Therefore, this topic focuses to discuss the algorithms, such as, similarity measures, and hierarchical clustering which includes single linkage, complete linkage and average linkage method. also, non-hierarchical clustering method, which is popular name K -mean method ' will be discussed. Finally, this paper will be described the advantages and disadvantages of every methods

  6. Cluster analysis

    CERN Document Server

    Everitt, Brian S; Leese, Morven; Stahl, Daniel

    2011-01-01

    Cluster analysis comprises a range of methods for classifying multivariate data into subgroups. By organizing multivariate data into such subgroups, clustering can help reveal the characteristics of any structure or patterns present. These techniques have proven useful in a wide range of areas such as medicine, psychology, market research and bioinformatics.This fifth edition of the highly successful Cluster Analysis includes coverage of the latest developments in the field and a new chapter dealing with finite mixture models for structured data.Real life examples are used throughout to demons

  7. Bulk Velocities and Orbits of Open Clusters

    Science.gov (United States)

    Frinchaboy, Peter M.; Chojnowski, D.

    2011-01-01

    We present bulk 3D dynamics for 10+ northern hemisphere open clusters. Utilizing WIYN/Hydra multi-fiber spectroscopic observations and Tycho and/or UCAC-3 proper motions, we determine cluster membership and bulk velocities. Cluster velocities are used to derive cluster orbits with comparison to previous studies. This work was partially supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-0602221 and by a TCU SERC grant

  8. Sedimentary pyrite δ34S differs from porewater sulfide in Santa Barbara Basin: Proposed role of organic sulfur

    Science.gov (United States)

    Raven, Morgan Reed; Sessions, Alex L.; Fischer, Woodward W.; Adkins, Jess F.

    2016-08-01

    Santa Barbara Basin sediments host a complex network of abiotic and metabolic chemical reactions that knit together the carbon, sulfur, and iron cycles. From a 2.1-m sediment core collected in the center of the basin, we present high-resolution profiles of the concentrations and isotopic compositions of all the major species in this system: sulfate, sulfide (∑H2S), elemental sulfur (S0), pyrite, extractable organic sulfur (OS), proto-kerogen S, total organic and dissolved inorganic carbon, and total and reducible iron. Below 10 cm depth, the core is characterized by low apparent sulfate reduction rates (pyrite forming in shallow sediments is ∼30‰ more 34S-depleted than coexisting ∑H2S in porewater. S0 has the same strongly 34S-depleted composition as pyrite where it forms near the sediment-water interface, though not at depth. This pattern is not easily explained by conventional hypotheses in which sedimentary pyrite derives from abiotic reactions with porewater ∑H2S or from the products of S0 disproportionation. Instead, we propose that pyrite formation in this environment occurs within sulfate reducing microbial aggregates or biofilms, where it reflects the isotopic composition of the immediate products of bacterial sulfate reduction. Porewater ∑H2S in Santa Barbara Basin may be more 34S-enriched than pyrite due to equilibration with relatively 34S-enriched OS. The difference between OS and pyrite δ34S values would then reflect the balance between microbial sulfide formation and the abundance of exchangeable OS. Both OS and pyrite δ34S records thus have the potential to provide valuable information about biogeochemical cycles and redox structure in sedimentary paleoenvironments.

  9. Occupational Clusters.

    Science.gov (United States)

    Pottawattamie County School System, Council Bluffs, IA.

    The 15 occupational clusters (transportation, fine arts and humanities, communications and media, personal service occupations, construction, hospitality and recreation, health occupations, marine science occupations, consumer and homemaking-related occupations, agribusiness and natural resources, environment, public service, business and office…

  10. Cancer Clusters

    Science.gov (United States)

    ... Peer Review and Funding Outcomes Step 4: Award Negotiation & Issuance Manage Your Award Grants Management Contacts Monitoring ... potentially hazardous working conditions, including suspected cancer clusters. Employees, authorized employee representatives, and employers can request these ...

  11. Cluster generator

    Science.gov (United States)

    Donchev, Todor I [Urbana, IL; Petrov, Ivan G [Champaign, IL

    2011-05-31

    Described herein is an apparatus and a method for producing atom clusters based on a gas discharge within a hollow cathode. The hollow cathode includes one or more walls. The one or more walls define a sputtering chamber within the hollow cathode and include a material to be sputtered. A hollow anode is positioned at an end of the sputtering chamber, and atom clusters are formed when a gas discharge is generated between the hollow anode and the hollow cathode.

  12. Bussines Clusters

    Directory of Open Access Journals (Sweden)

    Sarmiza Pencea

    2010-10-01

    Full Text Available Clusters are complex economic structures in which similar companies, their up-stream and down-stream business partners, universities, research institutes, educational units, various service providers, diverse private and public institutions concentrate geografically, striving to get economies of agglomeration and scale, to capitalize on the resulting spill over effects, to cut costs, to better harness resources, to exchange information and experience, to improve quality, innovation, skills and productivity. By somehow unexpectedly combining competition and cooperation, they form a new, sophisticated stage in the evolution of production structures in quest of higher efficiency. This paper forays into the world of clusters and clusterization, which seem to increasingly capture the interest of businesses, scholars and policy makers. It looks at what clusters are, how they arise, what are their specific features, what benefits and challenges they can generate for companies and for the regions in which they locate and if and how they should be fostered by industrial policy interventions. The conclusion is that clusters can be very important development triggers and therefore they should be encouraged and nurtured by adequate policy measures. They should not only be used as a regular policy tool, but be placed at the very center of the development strategies of emerging economies.

  13. Ativismo artístico: engajamento político e questões de gênero na obra de Barbara Kruger Artistic activism: political awareness and gender issues in Barbara Kruger's work

    Directory of Open Access Journals (Sweden)

    Lina Alves Arruda

    2011-08-01

    Full Text Available O presente artigo introduz e contextualiza as primeiras manifestações feministas que compuseram o panorama artístico do final da década de 1960 até 1980. São analisadas as circunstâncias históricas (incluindo a história da arte que facilitaram a ponte entre as esferas da arte e da política, bem como os problemas formais e estéticos que a prática artística ativista apresentou e sua recepção como movimento. Para tanto, nos basearemos no trabalho da artista norte-americana Barbara Kruger, que produziu obras fundamentais para a consolidação da arte feminista, abordando criticamente uma ampla variedade de temas relacionados à mulher (violência, aborto, identidade, papel social, estética. O conteúdo das obras de Kruger está em sintonia com importantes circunstâncias políticas e temas sociais contemporâneos à sua produção e estabelece relação direta com teorias feministas da época, permitindo uma análise do contexto artístico e sócio-político do período.The present article introduces and contextualizes early feminist artworks which emerged in the late 1960's up to the 1980's. It analyzes the historical circumstances which linked the artistic and social spheres, as well as the aesthetic and formal problems that came along with the artistic activist practice and its reception as a movement. The analysis will be based on the work of the North-American artist Barbara Kruger, who has produced fundamental pieces which consolidate feminist art. Kruger's work has a critical approach towards a large variety of subjects regarding women (violence, abortion, identity, social roles, aesthetics. The content of her work is engaged with important social matters and with the political scene at the period of its production, and it also bears a direct relation with the feminist theories of that period, reasons which allow for an analysis of both the artistic and the social-political contexts.

  14. Comparison of K-Means Clustering with Linear Probability Model, Linear Discriminant Function, and Logistic Regression for Predicting Two-Group Membership.

    Science.gov (United States)

    So, Tak-Shing Harry; Peng, Chao-Ying Joanne

    This study compared the accuracy of predicting two-group membership obtained from K-means clustering with those derived from linear probability modeling, linear discriminant function, and logistic regression under various data properties. Multivariate normally distributed populations were simulated based on combinations of population proportions,…

  15. A comparison of fuzzy logic and cluster renewal approaches for heat transfer modeling in a 1296 t/h CFB boiler with low level of flue gas recirculation

    Science.gov (United States)

    Błaszczuk, Artur; Krzywański, Jarosław

    2017-03-01

    The interrelation between fuzzy logic and cluster renewal approaches for heat transfer modeling in a circulating fluidized bed (CFB) has been established based on a local furnace data. The furnace data have been measured in a 1296 t/h CFB boiler with low level of flue gas recirculation. In the present study, the bed temperature and suspension density were treated as experimental variables along the furnace height. The measured bed temperature and suspension density were varied in the range of 1131-1156 K and 1.93-6.32 kg/m3, respectively. Using the heat transfer coefficient for commercial CFB combustor, two empirical heat transfer correlation were developed in terms of important operating parameters including bed temperature and also suspension density. The fuzzy logic results were found to be in good agreement with the corresponding experimental heat transfer data obtained based on cluster renewal approach. The predicted bed-to-wall heat transfer coefficient covered a range of 109-241 W/(m2K) and 111-240 W/(m2K), for fuzzy logic and cluster renewal approach respectively. The divergence in calculated heat flux recovery along the furnace height between fuzzy logic and cluster renewal approach did not exceeded ±2%.

  16. Examining the structural evolution of bicarbonate–water clusters: insights from photoelectron spectroscopy, basin-hopping structural search, and comparison with available IR spectral studies

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Hui [Chinese Academy of Sciences (CAS), Hefei (China). Lab. of Atmospheric Physico-Chemistry, Anhui Inst. of Optics & Fine Mechanics; Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Physical Sciences Division; Hou, Gao-Lei [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Physical Sciences Division; Liu, Yi-Rong [Chinese Academy of Sciences (CAS), Hefei (China). Lab. of Atmospheric Physico-Chemistry, Anhui Inst. of Optics & Fine Mechanics; Wang, Xue-Bin [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Physical Sciences Division; Huang, Wei [Chinese Academy of Sciences (CAS), Hefei (China). Lab. of Atmospheric Physico-Chemistry, Anhui Inst. of Optics & Fine Mechanics; Univ. of Science and Technology of China, Hefei (China). School of Environmental Science & Optoelectronic Technology

    2016-05-31

    Bicarbonate serves a crucial biochemical role in the physiological pH buffering system and also has important atmospheric implications. In the current study, HCO3$-$(H2O)n (n = 0-13) clusters were successfully produced via electrospray ionization of corresponding bulk salt solution, and were characterized by combining negative ion photoelectron spectroscopy and theoretical calculations. The photoelectron spectra reveal that the electron binding energy monotonically increases with the cluster size up to n = 10 and remains largely the same after n > 10. The photo-detaching feature of the solute HCO3$-$itself, which dominates in the small clusters, diminishes with increase of water coverage. Based on the charge distribution and molecular orbital analyses, the universal high electron binding energy tail that dominates in the larger clusters can be attributed to ionization of water. Thus, the transition of ionization from solute to solvent at the size larger than n=10 has been observed. Extensive theoretical structural search based on the Basin-Hopping unbiased method was carried out, and a plethora of low energy isomers have been obtained for each medium and large size. By comparing the simulated photoelectron spectra and calculated electron binding energies with the experiments, as well as by comparing the simulated infrared spectra with previously reported IR spectra, the probable global minima and the structural evolutionary routes are presented. The nature of bicarbonate-water interactions are mainly electrostatic as implied by the electron localization function (ELF) analysis.

  17. A comparison of fuzzy logic and cluster renewal approaches for heat transfer modeling in a 1296 t/h CFB boiler with low level of flue gas recirculation

    Directory of Open Access Journals (Sweden)

    Błaszczuk Artur

    2017-03-01

    Full Text Available The interrelation between fuzzy logic and cluster renewal approaches for heat transfer modeling in a circulating fluidized bed (CFB has been established based on a local furnace data. The furnace data have been measured in a 1296 t/h CFB boiler with low level of flue gas recirculation. In the present study, the bed temperature and suspension density were treated as experimental variables along the furnace height. The measured bed temperature and suspension density were varied in the range of 1131-1156 K and 1.93-6.32 kg/m3, respectively. Using the heat transfer coefficient for commercial CFB combustor, two empirical heat transfer correlation were developed in terms of important operating parameters including bed temperature and also suspension density. The fuzzy logic results were found to be in good agreement with the corresponding experimental heat transfer data obtained based on cluster renewal approach. The predicted bed-to-wall heat transfer coefficient covered a range of 109-241 W/(m2K and 111-240 W/(m2K, for fuzzy logic and cluster renewal approach respectively. The divergence in calculated heat flux recovery along the furnace height between fuzzy logic and cluster renewal approach did not exceeded ±2%.

  18. Fuzzy Clustering

    DEFF Research Database (Denmark)

    Berks, G.; Keyserlingk, Diedrich Graf von; Jantzen, Jan

    2000-01-01

    and clustering are the basic concerns in medicine. Classification depends on definitions of the classes and their required degree of participant of the elements in the cases' symptoms. In medicine imprecise conditions are the rule and therefore fuzzy methods are much more suitable than crisp ones. Fuzzy c...

  19. Cluster Matters

    DEFF Research Database (Denmark)

    Gulati, Mukesh; Lund-Thomsen, Peter; Suresh, Sangeetha

    2018-01-01

    In this chapter, we investigate corporate social responsibility (CSR) in industrial clusters in the Indian context. We use the definition of CSR as given in the Indian Ministry of Corporate Affairs’ National Voluntary Guidelines (NVGs) for Business Responsibility: ‘the commitment of an enterprise...

  20. Application of principal component and hierarchical cluster analyses in the classification of Serbian bottled waters and a comparison with waters from some European countries

    Directory of Open Access Journals (Sweden)

    Cvejanov Jelena Đ.

    2017-01-01

    Full Text Available The contents of major ions in bottled waters were analyzed by principal component (PCA and hierarchical cluster (HCA analysis in order to investigate if these techniques could provide the information necessary for classifications of the water brands marketed in Serbia. Data on the contents of Ca2+, Mg2+, Na+, K+, Cl-, SO4 2-, HCO3 - and total dissolved solids (TDS of 33 bottled waters was used as the input data set. The waters were separated into three main clusters according to their levels of TDS, Na+ and HCO3 -; sub-clustering revealed a group of soft waters with the lowest total hardness. Based on the determined chemical parameters, the Serbian waters were further compared with available literature data on bottled waters from some other European countries. To the best of our knowledge, this is the first report applying chemometric classification of bottled waters from different European countries, thereby representing a unique attempt in contrast to previous studies reporting the results primarily on a country-to-country scale. The diverse character of Serbian bottled waters was demonstrated as well as the usefulness of PCA and HCA in the fast classification of the water brands based on their main chemical parameters. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172050

  1. Functional connectivity analysis of the neural bases of emotion regulation: A comparison of independent component method with density-based k-means clustering method.

    Science.gov (United States)

    Zou, Ling; Guo, Qian; Xu, Yi; Yang, Biao; Jiao, Zhuqing; Xiang, Jianbo

    2016-04-29

    Functional magnetic resonance imaging (fMRI) is an important tool in neuroscience for assessing connectivity and interactions between distant areas of the brain. To find and characterize the coherent patterns of brain activity as a means of identifying brain systems for the cognitive reappraisal of the emotion task, both density-based k-means clustering and independent component analysis (ICA) methods can be applied to characterize the interactions between brain regions involved in cognitive reappraisal of emotion. Our results reveal that compared with the ICA method, the density-based k-means clustering method provides a higher sensitivity of polymerization. In addition, it is more sensitive to those relatively weak functional connection regions. Thus, the study concludes that in the process of receiving emotional stimuli, the relatively obvious activation areas are mainly distributed in the frontal lobe, cingulum and near the hypothalamus. Furthermore, density-based k-means clustering method creates a more reliable method for follow-up studies of brain functional connectivity.

  2. Analyses of hydrocarbons in BLM sediment intercalibration sample from Santa Barbara basin and spiked with API South Louisiana crude oil. A preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Farrington, J W; Tripp, B W; Sass, J

    1977-01-01

    A preliminary report is made of a BLM intercalibration sediment sample from the Santa Barbara basin spiked with South Louisiana crude oil. The two subsamples reported were analyzed by a procedure described in the appendix for which a separate abstract was written. Because of the high oil content of the sediment the usual thin layer chromatography procedure resulted in an overloaded plate. An appendix was indexed separately. (JSR)

  3. The SMART CLUSTER METHOD - adaptive earthquake cluster analysis and declustering

    Science.gov (United States)

    Schaefer, Andreas; Daniell, James; Wenzel, Friedemann

    2016-04-01

    the dataset receives a unique cluster-ID which links it to its respective cluster. Utilising the knowledge of cluster classification, the method has been adjusted to provide an earthquake declustering algorithm, which is compared to common existing methods used for declustering in PSHA in detail. The SCM provides a significantly more reliable declustering method in comparison to existing approaches. Instead of simply removing events from the dataset, it first identifies clusters and analyses them to avoid artefacts and non-physical implications. Furthermore, the SCM is the foundation of a more detailed analysis of global earthquake cluster activity. Using the knowledge of identified clusters, a detailed analysis of cluster properties can be undertaken.

  4. Cluster forcing

    DEFF Research Database (Denmark)

    Christensen, Thomas Budde

    , Portugal and New Zealand have adopted the concept. Public sector interventions that aim to support cluster development in industries most often focus upon economic policy goals such as enhanced employment and improved productivity, but rarely emphasise broader societal policy goals relating to e.......g. sustainability or quality of life. The purpose of this paper is to explore how and to what extent public sector interventions that aim at forcing cluster development in industries can support sustainable development as defined in the Brundtland tradition and more recently elaborated in such concepts as eco...... in 2000 by the Welsh Automotive Task Force under the Welsh Assembly Government. The Accelerate programme takes basically different two directions: The first one, which was the first to be launched, is concerned with the upgrading of existing supply chains in the automotive industry in Wales. The programme...

  5. Regional Innovation Clusters

    Data.gov (United States)

    Small Business Administration — The Regional Innovation Clusters serve a diverse group of sectors and geographies. Three of the initial pilot clusters, termed Advanced Defense Technology clusters,...

  6. Comparison of linear mixed model analysis and genealogy-based haplotype clustering with a Bayesian approach for association mapping in a pedigreed population

    DEFF Research Database (Denmark)

    Dashab, Golam Reza; Kadri, Naveen Kumar; Mahdi Shariati, Mohammad

    2012-01-01

    with divergent approaches for GWAS can be useful in gaining confidence on the QTL identified. In our comparison, GENMIX was found to be the best method in terms of power but it needs appropriate correction for multiple testing to avoid the false positives. This study shows that the issues of multiple testing...

  7. Calculation of Heats of Formation for Zn Complexes: Comparison of Density Functional Theory, Second Order Perturbation Theory, Coupled-Cluster and Complete Active Space Methods

    Science.gov (United States)

    Weaver, Michael N.; Ma, Dongxia; Kim, Hyun Jung

    2013-01-01

    Heats of formation were predicted for nine ZnX complexes (X= Zn, H, O, F2, S, Cl, Cl2, CH3, (CH3)2) using fourteen density functionals, MP2 calculations and the CCSD and CCSD(T) coupled-cluster methods. Calculations utilized the correlation consistent cc-pVTZ and aug-cc-pVTZ basis sets. Heats of formation were most accurately predicted by the TPSSTPSS and TPSSKCIS density functionals, and the BLYP, B3LYP, MP2, CCSD and CCSD(T) levels were among the poorest performing methods based on accuracy. A wide range of Zn2 equilibrium bond distances were predicted, indicating that many of the studied levels of theory may be unable to adequately describe this transition metal dimer. To further benchmark the accuracy of the density functional methods, high-level CASSCF and CASPT2 calculations were performed to estimate bond dissociation energies, equilibrium bond lengths and heats of formation for the diatomic Zn complexes and the latter two quantities were compared with the results of DFT, MP2 and coupled-cluster calculations as well as experimental values. PMID:24409106

  8. Fission of Polyanionic Metal Clusters

    Science.gov (United States)

    König, S.; Jankowski, A.; Marx, G.; Schweikhard, L.; Wolfram, M.

    2018-04-01

    Size-selected dianionic lead clusters Pbn2 -, n =34 - 56 , are stored in a Penning trap and studied with respect to their decay products upon photoexcitation. Contrary to the decay of other dianionic metal clusters, these lead clusters show a variety of decay channels. The mass spectra of the fragments are compared to the corresponding spectra of the monoanionic precursors. This comparison leads to the conclusion that, in the cluster size region below about n =48 , the fission reaction Pbn2 -→Pbn-10 -+Pb10- is the major decay process. Its disappearance at larger cluster sizes may be an indication of a nonmetal to metal transition. Recently, the pair of Pb10- and Pbn-10 - were observed as pronounced fragments in electron-attachment studies [S. König et al., Int. J. Mass Spectrom. 421, 129 (2017), 10.1016/j.ijms.2017.06.009]. The present findings suggest that this combination is the fingerprint of the decay of doubly charged lead clusters. With this assumption, the dianion clusters have been traced down to Pb212 -, whereas the smallest size for the direct observation was as high as n =28 .

  9. Water clustering in glassy polymers.

    Science.gov (United States)

    Davis, Eric M; Elabd, Yossef A

    2013-09-12

    In this study, water solubility and water clustering in several glassy polymers, including poly(methyl methacrylate) (PMMA), poly(styrene) (PS), and poly(vinylpyrrolidone) (PVP), were measured using both quartz spring microbalance (QSM) and Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy. Specifically, QSM was used to determine water solubility, while FTIR-ATR spectroscopy provided a direct, molecular-level measurement of water clustering. The Flory-Huggins theory was employed to obtain a measure of water-polymer interaction and water solubility, through both prediction and regression, where the theory failed to predict water solubility in both PMMA and PVP. Furthermore, a comparison of water clustering between direct FTIR-ATR spectroscopy measurements and predictions from the Zimm-Lundberg clustering analysis produced contradictory results. The failure of the Flory-Huggins theory and Zimm-Lundberg clustering analysis to describe water solubility and water clustering, respectively, in these glassy polymers is in part due to the equilibrium constraints under which these models are derived in contrast to the nonequilibrium state of glassy polymers. Additionally, FTIR-ATR spectroscopy results were compared to temperature-dependent diffusivity data, where a correlation between the activation energy for diffusion and the measured water clustering was observed.

  10. Node clustering for wireless sensor networks

    International Nuclear Information System (INIS)

    Bhatti, S.; Qureshi, I.A.; Memon, S.

    2012-01-01

    Recent years have witnessed considerable growth in the development and deployment of clustering methods which are not only used to maintain network resources but also increases the reliability of the WSNs (Wireless Sensor Network) and the facts manifest by the wide range of clustering solutions. Node clustering by selecting key parameters to tackle the dynamic behaviour of resource constraint WSN is a challenging issue. This paper highlights the recent progress which has been carried out pertaining to the development of clustering solutions for the WSNs. The paper presents classification of node clustering methods and their comparison based on the objectives, clustering criteria and methodology. In addition, the potential open issues which need to be considered for future work are high lighted. Keywords: Clustering, Sensor Network, Static, Dynamic

  11. D/H Ratios of Terrestrial Lipids from Santa Barbara Basin: A Preliminary Assessment of Paleoclimatic Relevance

    Science.gov (United States)

    Sessions, A. L.; Li, C.; Valentine, D. L.; Thiagarajan, N.

    2007-12-01

    Hydrogen isotope (D/H) ratios in sedimentary lipids are increasingly used as a proxy for terrestrial paleoclimate. In arid regions such as southern California, one of the principle problems is finding long-lived lakes to provide the necessary sedimentary archive for this proxy. As a potential alternative, here we explore the D/H record of terrestrial lipids preserved in a marginal marine suboxic basin, Santa Barbara Basin (SBB). Rapid sedimentation, long continuous records, significant terrestrial inputs, and excellent organic preservation all make this site attractive from a geological perspective. But does it record terrestrial climate? To test this, we conducted a survey of lipid D/H ratios in a sediment core collected at the depocenter of SBB, extending back 1200 years before present. Long-chain fatty acids, derived from terrestrial leaf waxes, exhibit virtually no downcore variation in D/H and are uncorrelated with the record of winter Palmer Drought Severity Index (PDSI) in southern California, a proxy for regional precipitation. Long-chain n-alkanes, also derived from leaf waxes, show considerable downcore variability in D/H but are also uncorrelated with PDSI. We believe the temporal variability for n-alkanes may be caused in part by addition of D-enriched fossil hydrocarbons due to increased erosion during wet periods. Regardless, none of these leafwax compounds are a robust paleoclimate proxy in SBB at sources, are well correlated with PDSI over this time interval and could serve as a viable paleoclimate proxy. We tentatively attribute the discrepancy between leaf-wax and aquatic biomarkers to a much longer soil residence time for leaf-wax compounds in the watershed, which effectively masks changes over centennial timescales.

  12. 3D Structural and Stratigraphic Architecture of the Northwest Santa Barbara Channel and Implications for Submarine Landslide Generation

    Science.gov (United States)

    Wright, A.; Kluesner, J. W.; Brothers, D. S.; Johnson, S. Y.

    2015-12-01

    Multiple submarine landslides have been previously documented on the north flank of the Santa Barbara Channel, and such failures are considered capable of generating local tsunamis. 2D seismic-reflection datasets provide a general view of regional framework geology, including faulting and folding associated with north-south compression. However, better understanding of the relationships between faults, folds, stratigraphic architecture, and submarine landslides can be obtained with 3D seismic datasets. In this study we use an industry 3D seismic-reflection volume that encompasses the slope and shelfbreak surrounding the Gaviota submarine landslide (3.8 km2) to investigate structural and stratigraphic controls on slope failure in this region. The depth-migrated seismic volume shows a network of stacked thrust faults, backthrusts, and splays that results in both broad and local zones of compression and folding along the slope and shelf. One localized zone of enhanced folding associated with small-offset thrust faults is located directly beneath the Gaviota landslide headwall, while another zone is located directly below an imaged seafloor fissure. In addition, 3D seismic attribute analysis provides insight into the shallow sedimentary section of the failed and non-failed sedimentary packages. Calculation of RMS amplitude and dominant frequency within a windowed region below the seafloor horizon delineates an apparent zone of gas-charged strata that onlaps onto older folded sediments. The up-dip limit of these gas-charged sediments aligns with the location of a seafloor fissure that extends westward from the Gaviota landslide headwall. We propose that the combination of deformation and fluid charging acted to pre-condition and trigger the failure of the Gaviota landslide, and as a result, the presence of these conditions along the fissure adjacent to the Gaviota landslide suggests this area should be considered landslide prone.

  13. Comparison of single-use and reusable metal laryngoscope blades for orotracheal intubation during rapid sequence induction of anesthesia: a multicenter cluster randomized study.

    Science.gov (United States)

    Amour, Julien; Le Manach, Yannick Le; Borel, Marie; Lenfant, François; Nicolas-Robin, Armelle; Carillion, Aude; Ripart, Jacques; Riou, Bruno; Langeron, Olivier

    2010-02-01

    Single-use metal laryngoscope blades are cheaper and carry a lower risk of infection than reusable metal blades. The authors compared single-use and reusable metal blades during rapid sequence induction of anesthesia in a multicenter cluster randomized trial. One thousand seventy-two adult patients undergoing general anesthesia under emergency conditions and requiring rapid sequence induction were randomly assigned on a weekly basis to either single-use or reusable metal blades (cluster randomization). After induction, a 60-s period was allowed to complete intubation. In the case of failed intubation, a second attempt was performed using the opposite type of blade. The primary endpoint was the rate of failed intubation, and the secondary endpoints were the incidence of complications (oxygen desaturation, lung aspiration, and/or oropharynx trauma) and the Cormack and Lehane score. Both groups were similar in their main characteristics, including the risk factors for difficult intubation. The rate of failed intubation was significantly decreased with single-use metal blades at the first attempt compared with reusable blades (2.8 vs. 5.4%, P < 0.05). In addition, the proportion of grades III and IV in Cormack and Lehane score were also significantly decreased with single-use metal blades (6 vs. 10%, P < 0.05). The global complication rate did not reach statistical significance, although the same trend was noted (6.8% vs. 11.5%, P = not significant). An investigator survey and a measure of illumination pointed that illumination might have been responsible for this result. The single-use metal blade was more efficient than a reusable metal blade in rapid sequence induction of anesthesia.

  14. The Extended Virgo Cluster Catalog

    Science.gov (United States)

    Rey, Soo-Chang

    2015-08-01

    We present a new catalog of galaxies in the wider region of the Virgo cluster, based on the Sloan Digital Sky Survey (SDSS) Data Release 7. The Extended Virgo Cluster Catalog (EVCC) covers an area of 725 deg2 or 60.1 Mpc2. It is 5.2 times larger than the footprint of the classical Virgo Cluster Catalog (VCC) and reaches out to 3.5 times the virial radius of the Virgo cluster. We selected 1324 spectroscopically targeted galaxies with radial velocities less than 3000 km s-1. In addition, 265 galaxies that have been overlooked in the SDSS spectroscopic survey but have available redshifts in the NASA Extragalactic Database are also included. Our selection process secured a total of 1589 galaxies, 676 of which are not included in the VCC. The certain and possible cluster members are defined by means of redshift comparison with a cluster infall model. We employed two independent and complementary galaxy classification schemes: the traditional morphological classification based on the visual inspection of optical images and a characterization of galaxies from their spectroscopic features. SDSS u, g, r, i, and z passband photometry of all EVCC galaxies was performed using Source Extractor. We compare the EVCC galaxies with the VCC in terms of morphology, spatial distribution, and luminosity function. The EVCC defines a comprehensive galaxy sample covering a wider range in galaxy density that is significantly different from the inner region of the Virgo cluster. It will be the foundation for forthcoming galaxy evolution studies in the extended Virgo cluster region, complementing ongoing and planned Virgo cluster surveys at various wavelengths.

  15. THE EXTENDED VIRGO CLUSTER CATALOG

    International Nuclear Information System (INIS)

    Kim, Suk; Rey, Soo-Chang; Lee, Youngdae; Chung, Jiwon; Pak, Mina; Yi, Wonhyeong; Lee, Woong; Jerjen, Helmut; Lisker, Thorsten; Sung, Eon-Chang

    2014-01-01

    We present a new catalog of galaxies in the wider region of the Virgo cluster, based on the Sloan Digital Sky Survey (SDSS) Data Release 7. The Extended Virgo Cluster Catalog (EVCC) covers an area of 725 deg 2 or 60.1 Mpc 2 . It is 5.2 times larger than the footprint of the classical Virgo Cluster Catalog (VCC) and reaches out to 3.5 times the virial radius of the Virgo cluster. We selected 1324 spectroscopically targeted galaxies with radial velocities less than 3000 km s –1 . In addition, 265 galaxies that have been overlooked in the SDSS spectroscopic survey but have available redshifts in the NASA Extragalactic Database are also included. Our selection process secured a total of 1589 galaxies, 676 of which are not included in the VCC. The certain and possible cluster members are defined by means of redshift comparison with a cluster infall model. We employed two independent and complementary galaxy classification schemes: the traditional morphological classification based on the visual inspection of optical images and a characterization of galaxies from their spectroscopic features. SDSS u, g, r, i, and z passband photometry of all EVCC galaxies was performed using Source Extractor. We compare the EVCC galaxies with the VCC in terms of morphology, spatial distribution, and luminosity function. The EVCC defines a comprehensive galaxy sample covering a wider range in galaxy density that is significantly different from the inner region of the Virgo cluster. It will be the foundation for forthcoming galaxy evolution studies in the extended Virgo cluster region, complementing ongoing and planned Virgo cluster surveys at various wavelengths

  16. THE EXTENDED VIRGO CLUSTER CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Suk; Rey, Soo-Chang; Lee, Youngdae; Chung, Jiwon; Pak, Mina; Yi, Wonhyeong; Lee, Woong [Department of Astronomy and Space Science, Chungnam National University, 99 Daehak-ro, Daejeon 305-764 (Korea, Republic of); Jerjen, Helmut [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston, ACT 2611 (Australia); Lisker, Thorsten [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg (ZAH), Mönchhofstraße 12-14, D-69120 Heidelberg (Germany); Sung, Eon-Chang [Korea Astronomy and Space Science institute, 776 Daedeokdae-ro, Daejeon 305-348 (Korea, Republic of)

    2015-01-01

    We present a new catalog of galaxies in the wider region of the Virgo cluster, based on the Sloan Digital Sky Survey (SDSS) Data Release 7. The Extended Virgo Cluster Catalog (EVCC) covers an area of 725 deg{sup 2} or 60.1 Mpc{sup 2}. It is 5.2 times larger than the footprint of the classical Virgo Cluster Catalog (VCC) and reaches out to 3.5 times the virial radius of the Virgo cluster. We selected 1324 spectroscopically targeted galaxies with radial velocities less than 3000 km s{sup –1}. In addition, 265 galaxies that have been overlooked in the SDSS spectroscopic survey but have available redshifts in the NASA Extragalactic Database are also included. Our selection process secured a total of 1589 galaxies, 676 of which are not included in the VCC. The certain and possible cluster members are defined by means of redshift comparison with a cluster infall model. We employed two independent and complementary galaxy classification schemes: the traditional morphological classification based on the visual inspection of optical images and a characterization of galaxies from their spectroscopic features. SDSS u, g, r, i, and z passband photometry of all EVCC galaxies was performed using Source Extractor. We compare the EVCC galaxies with the VCC in terms of morphology, spatial distribution, and luminosity function. The EVCC defines a comprehensive galaxy sample covering a wider range in galaxy density that is significantly different from the inner region of the Virgo cluster. It will be the foundation for forthcoming galaxy evolution studies in the extended Virgo cluster region, complementing ongoing and planned Virgo cluster surveys at various wavelengths.

  17. Photoabsorption of small sodium and magnesium clusters

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter

    2004-01-01

    We predict the strong enhancement in the photoabsorption of small Mg clusters in the region of 4-5 eV due to the resonant excitation of the plasmon oscillations of cluster electrons. The photoabsorption spectra for neutral Mg clusters consisting of up to N=11 atoms have been calculated using it a...... deformation is analysed. The reliability of the used calculation scheme has been proved by performing the test calculation for a number of sodium clusters and the comparison of the results obtained with the results of other methods and experiment....

  18. Comparing the performance of biomedical clustering methods

    DEFF Research Database (Denmark)

    Wiwie, Christian; Baumbach, Jan; Röttger, Richard

    2015-01-01

    expression to protein domains. Performance was judged on the basis of 13 common cluster validity indices. We developed a clustering analysis platform, ClustEval (http://clusteval.mpi-inf.mpg.de), to promote streamlined evaluation, comparison and reproducibility of clustering results in the future....... This allowed us to objectively evaluate the performance of all tools on all data sets with up to 1,000 different parameter sets each, resulting in a total of more than 4 million calculated cluster validity indices. We observed that there was no universal best performer, but on the basis of this wide......-ranging comparison we were able to develop a short guideline for biomedical clustering tasks. ClustEval allows biomedical researchers to pick the appropriate tool for their data type and allows method developers to compare their tool to the state of the art....

  19. Preventing Sexual Violence in Adolescence: Comparison of a Scientist-Practitioner Program and a Practitioner Program Using a Cluster-Randomized Design.

    Science.gov (United States)

    Muck, Christoph; Schiller, Eva-Maria; Zimmermann, Maria; Kärtner, Joscha

    2018-02-01

    Numerous school-based prevention programs have been developed by scientists and practitioners to address sexual violence in adolescence. However, such programs struggle with two major challenges. First, the effectiveness of many well-established practitioner programs has not been rigorously evaluated. Second, effective scientific programs may be hard to implement into everyday school practice. Combining the knowledge of scientists and practitioners in a scientist-practitioner program could be a helpful compromise. The aim of the present study is to evaluate the effects of a scientist-practitioner program and a practitioner program using a cluster-randomized experimental design. Twenty-seven school classes were randomly assigned to either one of two programs or a control group. Outcome variables (knowledge, attitudes, behavior, and iatrogenic effects) were assessed at pretest, posttest, and a 6-month follow-up for 453 adolescents (55% female, Mage = 14.18). Short-term effects were found in both programs regarding general knowledge, knowledge of professional help, and victim-blaming attitudes. Long-term effects were found in both programs regarding general knowledge and knowledge of professional help and, in the practitioner program, in a reduction of victimization. No other effects were found on attitudes and behavior. No iatrogenic effects in the form of increased anxiety were found. Both the scientist-practitioner and the practitioner program show promise for the prevention of sexual violence in adolescence; in particular, the practitioner program may be a more cost-effective method.

  20. Vaccination Coverage Cluster Surveys in Middle Dreib - Akkar, Lebanon: Comparison of Vaccination Coverage in Children Aged 12-59 Months Pre- and Post-Vaccination Campaign.

    Science.gov (United States)

    Rossi, Rodolfo; Assaad, Ramia; Rebeschini, Arianna; Hamadeh, Randa

    2016-01-01

    With the high proportion of refugee population throughout Lebanon and continuous population movement, it is sensible to believe that, in particular vulnerable areas, vaccination coverage may not be at an optimal level. Therefore, we assessed the vaccination coverage in children under 5 in a district of the Akkar governorate before and after a vaccination campaign. During the vaccination campaign, conducted in August 2015, 2,509 children were vaccinated. We conducted a pre- and post-vaccination campaign coverage surveys adapting the WHO EPI cluster survey to the Lebanese MoPH vaccination calendar. Percentages of coverage for each dose of each vaccine were calculated for both surveys. Factors associated with complete vaccination were explored. Comparing the pre- with the post-campaign surveys, coverage for polio vaccine increased from 51.9% to 84.3%, for Pentavalent from 49.0% to 71.9%, for MMR from 36.2% to 61.0%, while the percentage of children with fully updated vaccination calendar increased from 32.9% to 53.8%. While Lebanese children were found to be better covered for some antigens compared to Syrians at the first survey, this difference disappeared at the post-campaign survey. Awareness and logistic obstacles were the primary reported causes of not complete vaccination in both surveys. Vaccination campaigns remain a quick and effective approach to increase vaccination coverage in crisis-affected areas. However, campaigns cannot be considered as a replacement of routine vaccination services to maintain a good level of coverage.

  1. Soil erosion rates in two karst peak-cluster depression basins of northwest Guangxi, China: Comparison of the RUSLE model with 137Cs measurements

    Science.gov (United States)

    Feng, Teng; Chen, Hongsong; Polyakov, Viktor O.; Wang, Kelin; Zhang, Xinbao; Zhang, Wei

    2016-01-01

    Reliable estimation of erosion in karst areas is difficult because of the heterogeneous nature of infiltration and sub-surface drainage. Understanding the processes involved is a key requirement for managing against karst rock desertification. This study used the revised Universal Soil Loss Equation (RUSLE) to estimate the annual soil erosion rates on hillslopes and compared them with 137Cs budget in the depressions at two typical karst peak-cluster depression basins in northwest Guangxi, southwestern China. Runoff plots data were used to calibrate the slope length factor (L) of the RUSLE model by adjusting the accumulated area threshold. The RUSLE model was sensitive to the value of the threshold and required DEMs with 1 m resolution, due to the discontinuous nature of the overland flow. The average annual soil erosion rates on hillslopes simulated by the RUSLE were 0.22 and 0.10 Mg ha- 1 y- 1 during 2006 through 2011 in the partially cultivated GZ1 and the undisturbed GZ2 basins, respectively. The corresponding deposition rates in the depressions agreed well with the 137Cs records when recent changes in precipitation and land use were taken into consideration. The study suggests that attention should be given to the RUSLE-L factor when applying the RUSLE on karst hillslopes because of the discontinuous nature of runoff and significant underground seepage during storm events that effectively reduces the effects of slope length.

  2. Sound quality prediction based on systematic metric selection and shrinkage: Comparison of stepwise, lasso, and elastic-net algorithms and clustering preprocessing

    Science.gov (United States)

    Gauthier, Philippe-Aubert; Scullion, William; Berry, Alain

    2017-07-01

    Sound quality is the impression of quality that is transmitted by the sound of a device. Its importance in sound and acoustical design of consumer products no longer needs to be demonstrated. One of the challenges is the creation of a prediction model that is able to predict the results of a listening test while using metrics derived from the sound stimuli. Often, these models are either derived using linear regression on a limited set of experimenter-selected metrics, or using more complex algorithms such as neural networks. In the former case, the user-selected metrics can bias the model and reflect the engineer pre-conceived idea of sound quality while missing potential features. In the latter case, although prediction might be efficient, the model is often in the form of a black-box which is difficult to use as a sound design guideline for engineers. In this paper, preprocessing by participants clustering and three different algorithms are compared in order to construct a sound quality prediction model that does not suffer from these limitations. The lasso, elastic-net and stepwise algorithms are tested for listening tests of consumer product for which 91 metrics are used as potential predictors. Based on the reported results, it is shown that the most promising algorithm is the lasso which is able to (1) efficiently limit the number of metrics, (2) most accurately predict the results of listening tests, and (3) provide a meaningful model that can be used as understandable design guidelines.

  3. Coral: an integrated suite of visualizations for comparing clusterings

    Directory of Open Access Journals (Sweden)

    Filippova Darya

    2012-10-01

    Full Text Available Abstract Background Clustering has become a standard analysis for many types of biological data (e.g interaction networks, gene expression, metagenomic abundance. In practice, it is possible to obtain a large number of contradictory clusterings by varying which clustering algorithm is used, which data attributes are considered, how algorithmic parameters are set, and which near-optimal clusterings are chosen. It is a difficult task to sift though such a large collection of varied clusterings to determine which clustering features are affected by parameter settings or are artifacts of particular algorithms and which represent meaningful patterns. Knowing which items are often clustered together helps to improve our understanding of the underlying data and to increase our confidence about generated modules. Results We present Coral, an application for interactive exploration of large ensembles of clusterings. Coral makes all-to-all clustering comparison easy, supports exploration of individual clusterings, allows tracking modules across clusterings, and supports identification of core and peripheral items in modules. We discuss how each visual component in Coral tackles a specific question related to clustering comparison and provide examples of their use. We also show how Coral could be used to visually and quantitatively compare clusterings with a ground truth clustering. Conclusion As a case study, we compare clusterings of a recently published protein interaction network of Arabidopsis thaliana. We use several popular algorithms to generate the network’s clusterings. We find that the clusterings vary significantly and that few proteins are consistently co-clustered in all clusterings. This is evidence that several clusterings should typically be considered when evaluating modules of genes, proteins, or sequences, and Coral can be used to perform a comprehensive analysis of these clustering ensembles.

  4. Velocity evolution of galaxy clustering

    Energy Technology Data Exchange (ETDEWEB)

    Saslaw, W.C.; Aarseth, S.J.

    1982-02-15

    We have examined the changing velocity distribution of galaxies as they cluster in computer models of the expanding universe. The models are 4000-body numerical simulations of galaxies with a large range of masses interacting gravitationally. Clustering in velocity space is measured by calculating the residual peculiar velocities around the Hubble expansion. These form ''Hubble streaks as clustering progresses. We distinguish isolated field galaxies from clustered galaxies. In contrast to the usual belief, the velocity dispersion of the most extreme field galaxies does not decrease adiabatically. Rather, it is dominated by the perturbations of distant large clusters as they form and it decreases much more slowly than the inverse expansion length scale, R/sup -1/. The velocity dispersion of extreme field galaxies is a good cosmological indicator of ..cap omega.. = rho/rho/sub crit/. Preliminary comparison of several simulations with observtions shows that our universe agrees better with low density models, ..cap omega..< or =0.1. The velocity dispersion of cluster centers of mass is a good cosmological marker as well. We also suggest another new method for estimating ..cap omega.., based on the history of extreme field galaxies.

  5. Heavy hitters via cluster-preserving clustering

    DEFF Research Database (Denmark)

    Larsen, Kasper Green; Nelson, Jelani; Nguyen, Huy L.

    2016-01-01

    , providing correctness whp. In fact, a simpler version of our algorithm for p = 1 in the strict turnstile model answers queries even faster than the "dyadic trick" by roughly a log n factor, dominating it in all regards. Our main innovation is an efficient reduction from the heavy hitters to a clustering...... problem in which each heavy hitter is encoded as some form of noisy spectral cluster in a much bigger graph, and the goal is to identify every cluster. Since every heavy hitter must be found, correctness requires that every cluster be found. We thus need a "cluster-preserving clustering" algorithm......, that partitions the graph into clusters with the promise of not destroying any original cluster. To do this we first apply standard spectral graph partitioning, and then we use some novel combinatorial techniques to modify the cuts obtained so as to make sure that the original clusters are sufficiently preserved...

  6. Modeling of depth to base of Last Glacial Maximum and seafloor sediment thickness for the California State Waters Map Series, eastern Santa Barbara Channel, California

    Science.gov (United States)

    Wong, Florence L.; Phillips, Eleyne L.; Johnson, Samuel Y.; Sliter, Ray W.

    2012-01-01

    Models of the depth to the base of Last Glacial Maximum and sediment thickness over the base of Last Glacial Maximum for the eastern Santa Barbara Channel are a key part of the maps of shallow subsurface geology and structure for offshore Refugio to Hueneme Canyon, California, in the California State Waters Map Series. A satisfactory interpolation of the two datasets that accounted for regional geologic structure was developed using geographic information systems modeling and graphics software tools. Regional sediment volumes were determined from the model. Source data files suitable for geographic information systems mapping applications are provided.

  7. Controls on the Location of Hydrocarbon Seeps in the Northern Santa Barbara Channel Shelf, California: A Geologic Plumbing System.

    Science.gov (United States)

    Broderick, K. G.

    2001-12-01

    The liquid and gaseous hydrocarbon seeps in the Santa Barbara Channel, CA, are among the most prolific natural seeps in the world, with gas and oil emissions on the order of 1 x 105 m3/day and 1-2 x 104 liters/day, respectively. A previously-mapped master fault at depth is probably the main transport pathway of hydrocarbons from the Miocene-age Monterey Formation source rock. At the sea floor seep plume vent locations are broadly coincident with kilometer-scale geologic structures in the northern channel shelf. The major trends of the seeps follow the ESE axes of the offshore Coal Oil Point and South Ellwood Anticlines. Seep vents are also found above source-rock structural highs along the fold axes. It is likely that the principal near-surface pathways of gas and liquid flow occur along fractures in the crests of these structural folds. A new interpretation of 100 kHz side scan sonar data suggests, however, that spatial and temporal variations in exact locations of highest seep intensity may be controlled by three factors: 1) the influence of Holocene sediment overburden, 2) lithologic contrasts in the overlying Sisquoc cap rock, and 3) a series of previously unidentified fractures or cross-faults. Some amount of variation in the locations of hydrocarbon vents may occur as westerly and southwesterly bottom currents on the shelf transport and redeposit unconsolidated sediments throughout the study area burying the vents. Detailed geologic seafloor mapping using sonar data, dart core data, and a preliminary sediment cover map indicates relatively few seeps in areas with sediment overburden greater than 4 meters. This may be attributed to a sealing effect as tar saturates and consolidates the overlying sediments, or to the emission of bubble plumes too diffuse to be detected in the sonar data. Seeps have also been mapped to coincide with areas on the seafloor that exhibit distinct across-strike changes in outcrop pattern. Hydrocarbon fluid flow here likely favors

  8. The relationship between active deformation, stratigraphic architecture, and submarine slope failure in the Santa Barbara Channel, southern California

    Science.gov (United States)

    Wright, A.; Brothers, D. S.; Kluesner, J.; Dugan, B.; Johnson, S. Y.

    2017-12-01

    Multiple submarine landslides are documented along the slope of the seismically active Santa Barbara Basin and are proposed to have been capable of generating tsunamis with 2 - 20 m wave heights. Questions remain as to what factors preconditioned sections of the continental slope for failure and whether adjacent slopes are at risk for future failure. For example, the Gaviota landslide (0.01 - 0.02 km3) and Goleta landslide complex (3 - 4 km3) are surrounded by sections of intact slope sediment, but show signs of incipient failure, emphasizing the need for detailed hazard assessment of the region. Past studies have had to rely on legacy 2D seismic reflection datasets to analyze the regional framework geology and these data did not provide the necessary resolution to identity active faults and folds beneath the slope. Here we integrate 3D multichannel seismic (MCS) reflection volumes (acquired in 1995) as well as high-resolution 2D MCS and multibeam bathymetry datasets (acquired in 2016) to analyze the relationships between slope failure and near-surface deformation, stratigraphic architecture, and substrate fluid flow. The new high-resolution data reveal evidence for active deformation along a previously undocumented network of en echelon faults striking 25° counterclockwise to the dominant structural grain of the region. We observe a locally uplifted zone beneath the Gaviota slide that evidently deforms 90 ka sediment. Analogous patterns of deformation are identified beneath adjacent sections of intact slope, suggesting these areas may be preconditioned for failure. Thinning and onlap of fluid-saturated basin strata occurs above zones of active uplift and fault-propagation folding. We present a conceptual model for differential compaction that induces a lateral pressure gradient and updip migration of fluids, which creates a mid-slope zone of overpressure (i.e., reduced shear strength) along the axis of folding and explains the positioning of the Gaviota slide and

  9. Actualidad de la fenomenología: la fenomenología de la vida de Renaud Barbaras

    Directory of Open Access Journals (Sweden)

    Larisson, Mariana

    2009-04-01

    Full Text Available In recent years we have seen a resurgence of a number of concepts connected to the notion of life, as well as to the several problematic that have their origin in this notion. Such problematic have come to be fashionable in fields such as science, politics, culture or in recent developments in economics and technology. Against this historical background, philosophical reflection on the phenomenon of life has not been, however, undertaken. In this context, the appearance of a philosophical attempt that presents itself as a phenomenology of life is of immediate interest and relevance. Such is the work of Renaud Bárbaras entitled Introduction à une phénoménologie de la vie (2008. The following analysis focuses on this text and attempts to bring to light its great problematic and possible implications.En los últimos años hemos asistido al surgimiento de toda una serie de conceptos ligados a la noción de vida y a las problemáticas que de ella se derivan. Las mismas que, hoy en día, se encuentran en boga en ámbitos tan diversos como la ciencia, la política, la cultura o los nuevos desarrollos económicos y tecnológicos. Sin embargo, y con este contexto histórico de fondo, la reflexión filosófica sobre el fenómeno de la vida resta aún por hacerse. En este sentido, la aparición de una filosofía que se presenta a sí misma como una fenomenología de la vida cobra una actualidad e interés inusitados. Tal es el caso de la reciente obra de Renaud Barbaras Introduction à une phénoménologie de la vie (2008, de la que se ocupa el presente escrito, en el que intentaremos poner de relieve la problemática que el texto revela y sus posibles derivaciones.

  10. A comparison of two short education programs for improving low back pain-related disability in the elderly: a cluster randomized controlled trial.

    Science.gov (United States)

    Kovacs, Francisco; Abraira, Víctor; Santos, Severo; Díaz, Elena; Gestoso, Mario; Muriel, Alfonso; Gil del Real, María Teresa; Mufraggi, Nicole; Noguera, Juan; Zamora, Javier

    2007-05-01

    Cluster randomized clinical trial. To assess the effectiveness of 2 minimal education programs for improving low back pain (LBP)-related disability in the elderly. No education program has shown effectiveness on low back pain (LBP)-related disability in the elderly. A total of 129 nursing homes (6389 residents) in northern Spain were invited to participate in the study. The actual participants were 12 nursing homes randomly assigned to 3 groups and 661 subjects. An independent physician gave a 20-minute talk with slide projections summarizing the content of the Back Book (active management group), the Back Guide (postural hygiene group), and a pamphlet on cardiovascular health (controls). Disability was measured with the Roland-Morris questionnaire (RMQ). Blind assessments were performed before the intervention, and 30 and 180 days later. The effect of the intervention on disability was estimated by generalized mixed linear random effects models. Mean age of participants ranged between 79.9 and 81.2 years. Disability improved in all groups, but at the 30-day assessment the postural education group showed an additional improvement of 1.1 (95% confidence interval, 0.2-1.9), RMQ points and at the 180-day assessment the active education group an additional improvement of 2.0 (95% confidence interval, 0.6-3.4). In the subset of subjects with LBP when entering the study, postural education had no advantages over controls, while an additional improvement of 3.0 (95% confidence interval, 1.5- 4.5) RMQ points at the 180-day assessment was observed in the active education group. In institutionalized elderly, the handing out of the Back Book supported by a 20-minute group talk improves disability 6 months later, and is even more effective in those subjects with LBP.

  11. Vaccination Coverage Cluster Surveys in Middle Dreib – Akkar, Lebanon: Comparison of Vaccination Coverage in Children Aged 12-59 Months Pre- and Post-Vaccination Campaign

    Science.gov (United States)

    Assaad, Ramia; Rebeschini, Arianna; Hamadeh, Randa

    2016-01-01

    Introduction With the high proportion of refugee population throughout Lebanon and continuous population movement, it is sensible to believe that, in particular vulnerable areas, vaccination coverage may not be at an optimal level. Therefore, we assessed the vaccination coverage in children under 5 in a district of the Akkar governorate before and after a vaccination campaign. During the vaccination campaign, conducted in August 2015, 2,509 children were vaccinated. Materials and Methods We conducted a pre- and post-vaccination campaign coverage surveys adapting the WHO EPI cluster survey to the Lebanese MoPH vaccination calendar. Percentages of coverage for each dose of each vaccine were calculated for both surveys. Factors associated with complete vaccination were explored. Results Comparing the pre- with the post-campaign surveys, coverage for polio vaccine increased from 51.9% to 84.3%, for Pentavalent from 49.0% to 71.9%, for MMR from 36.2% to 61.0%, while the percentage of children with fully updated vaccination calendar increased from 32.9% to 53.8%. While Lebanese children were found to be better covered for some antigens compared to Syrians at the first survey, this difference disappeared at the post-campaign survey. Awareness and logistic obstacles were the primary reported causes of not complete vaccination in both surveys. Discussion Vaccination campaigns remain a quick and effective approach to increase vaccination coverage in crisis-affected areas. However, campaigns cannot be considered as a replacement of routine vaccination services to maintain a good level of coverage. PMID:27992470

  12. santa_barbara.grd

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC builds and distributes high-resolution, coastal digital elevation models (DEMs) that integrate ocean bathymetry and land topography to support NOAA's mission to...

  13. Toward understanding environmental effects in SDSS clusters

    Energy Technology Data Exchange (ETDEWEB)

    Einasto, Jaan; Tago, E.; Einasto, M.; Saar, E.; Suhhonenko, I.; /Tartu Observ.; Heinamaki, P.; /Tartu Observ. /Tuorla Observ.; Hutsi, G.; /Tartu Observ. /Garching, Max; Tucker, D.L.; /Fermilab

    2004-11-01

    We find clusters and superclusters of galaxies using the Data Release 1 of the Sloan Digital Sky Survey. We determine the luminosity function of clusters and find that clusters in a high-density environment have a luminosity a factor of {approx}5 higher than in a low-density environment. We also study clusters and superclusters in numerical simulations. Simulated clusters in a high-density environment are also more massive than those in a low-density environment. Comparison of the density distribution at various epochs in simulations shows that in large low-density regions (voids) dynamical evolution is very slow and stops at an early epoch. In contrast, in large regions of higher density (superclusters) dynamical evolution starts early and continues until the present; here particles cluster early, and by merging of smaller groups very rich systems of galaxies form.

  14. Author Clustering on Large Bibliographies

    CERN Document Server

    Sterz, Christoph

    2014-01-01

    We analyze and design an algorithm for clustering large sets of authors in Bibliographies. Not considering a distance function for a mutual comparison, but transforming the data into a multidimensional metric space, the algorithm described is similar to locally sensitive hashing. The task lies in the field of Record-Linkage. The algorithm was designed and performed based on the data of the CERN Document Server, consisting out of more than 1.7 million metadata entries and is part of the digital assets-managing-software invenio. Meant as a prototype, the algorithm performs efficiently, clustering all authors on CDS in under 30 minutes. We will discuss extensions improving the recall rate, wich still remains inferior to the currently used clustering-approach.

  15. Brightest Cluster Galaxies in REXCESS Clusters

    Science.gov (United States)

    Haarsma, Deborah B.; Leisman, L.; Bruch, S.; Donahue, M.

    2009-01-01

    Most galaxy clusters contain a Brightest Cluster Galaxy (BCG) which is larger than the other cluster ellipticals and has a more extended profile. In the hierarchical model, the BCG forms through many galaxy mergers in the crowded center of the cluster, and thus its properties give insight into the assembly of the cluster as a whole. In this project, we are working with the Representative XMM-Newton Cluster Structure Survey (REXCESS) team (Boehringer et al 2007) to study BCGs in 33 X-ray luminous galaxy clusters, 0.055 < z < 0.183. We are imaging the BCGs in R band at the Southern Observatory for Astrophysical Research (SOAR) in Chile. In this poster, we discuss our methods and give preliminary measurements of the BCG magnitudes, morphology, and stellar mass. We compare these BCG properties with the properties of their host clusters, particularly of the X-ray emitting gas.

  16. Partitional clustering algorithms

    CERN Document Server

    2015-01-01

    This book summarizes the state-of-the-art in partitional clustering. Clustering, the unsupervised classification of patterns into groups, is one of the most important tasks in exploratory data analysis. Primary goals of clustering include gaining insight into, classifying, and compressing data. Clustering has a long and rich history that spans a variety of scientific disciplines including anthropology, biology, medicine, psychology, statistics, mathematics, engineering, and computer science. As a result, numerous clustering algorithms have been proposed since the early 1950s. Among these algorithms, partitional (nonhierarchical) ones have found many applications, especially in engineering and computer science. This book provides coverage of consensus clustering, constrained clustering, large scale and/or high dimensional clustering, cluster validity, cluster visualization, and applications of clustering. Examines clustering as it applies to large and/or high-dimensional data sets commonly encountered in reali...

  17. The distribution of clusters in the southern ACO catalog

    International Nuclear Information System (INIS)

    Batuski, D.J.; Bahcall, N.A.; Olowin, R.P.; Burns, J.O.

    1989-01-01

    The distribution of rich clusters of galaxies in the new southern catalog of Abell, Corwin, and Olowin (ACO, 1989) is examined. A comparison with the cluster distribution in the northern Abell catalog, published in 1958, is presented. The similarities as well as the differences between the catalogs are highlighted. The angular cluster correlation function of the ACO catalog is consistent with the Abell cluster correlation, showing strong superclustering to about 50/h Mpc. The correlation amplitude scales with depth, as expected for real spatial clustering. Plate-to-plate variation effects are investigated; no significant impact of the latter on the cluster correlation is observed. 19 refs

  18. Interactive visual exploration and refinement of cluster assignments.

    Science.gov (United States)

    Kern, Michael; Lex, Alexander; Gehlenborg, Nils; Johnson, Chris R

    2017-09-12

    With ever-increasing amounts of data produced in biology research, scientists are in need of efficient data analysis methods. Cluster analysis, combined with visualization of the results, is one such method that can be used to make sense of large data volumes. At the same time, cluster analysis is known to be imperfect and depends on the choice of algorithms, parameters, and distance measures. Most clustering algorithms don't properly account for ambiguity in the source data, as records are often assigned to discrete clusters, even if an assignment is unclear. While there are metrics and visualization techniques that allow analysts to compare clusterings or to judge cluster quality, there is no comprehensive method that allows analysts to evaluate, compare, and refine cluster assignments based on the source data, derived scores, and contextual data. In this paper, we introduce a method that explicitly visualizes the quality of cluster assignments, allows comparisons of clustering results and enables analysts to manually curate and refine cluster assignments. Our methods are applicable to matrix data clustered with partitional, hierarchical, and fuzzy clustering algorithms. Furthermore, we enable analysts to explore clustering results in context of other data, for example, to observe whether a clustering of genomic data results in a meaningful differentiation in phenotypes. Our methods are integrated into Caleydo StratomeX, a popular, web-based, disease subtype analysis tool. We show in a usage scenario that our approach can reveal ambiguities in cluster assignments and produce improved clusterings that better differentiate genotypes and phenotypes.

  19. Diversity among galaxy clusters

    International Nuclear Information System (INIS)

    Struble, M.F.; Rood, H.J.

    1988-01-01

    The classification of galaxy clusters is discussed. Consideration is given to the classification scheme of Abell (1950's), Zwicky (1950's), Morgan, Matthews, and Schmidt (1964), and Morgan-Bautz (1970). Galaxies can be classified based on morphology, chemical composition, spatial distribution, and motion. The correlation between a galaxy's environment and morphology is examined. The classification scheme of Rood-Sastry (1971), which is based on clusters's morphology and galaxy population, is described. The six types of clusters they define include: (1) a cD-cluster dominated by a single large galaxy, (2) a cluster dominated by a binary, (3) a core-halo cluster, (4) a cluster dominated by several bright galaxies, (5) a cluster appearing flattened, and (6) an irregularly shaped cluster. Attention is also given to the evolution of cluster structures, which is related to initial density and cluster motion

  20. Tracking Identity: Opportunity, Success, and Affiliation with Science among Fifth-Grade Latina/o Youth of Santa Barbara, California

    Science.gov (United States)

    Maas, Grayson Ford

    This dissertation is an investigation into the American public education system at the elementary school level. It highlights important factors that shape the organizational structure of schools and classrooms, and in turn, how they engender disparities in the ways students experience education, namely, in the opportunities made available to them to achieve and succeed at a high level. This dissertation operates at the confluence of notions about class, gender, language, and race, especially as they revolve around public education and the hegemonic meritocratic discourse on which it is founded. This dissertation engages and contributes to scholarship within the following areas: The political economy of education; discourse and the dialectical relationship between agency and structure; cultural perspectives on identity, voice, and learning; and, Latinas/os in science education. The data that serve as the basis for the findings presented in this dissertation were collected throughout a three-phase yearlong ethnographic study of the two tracked fifth-grade classrooms at Amblen Elementary School, serving a socioeconomically disadvantaged Latina/o student population in Santa Barbara, California. In classrooms all across the nation, while it remains true that Latina/o students disproportionally take up space in the lower-tracked courses and not in the higher ones, this study does not examine inequality in tracking assignments made along ethnic/racial lines (as 100% of the students that participated in this research identify as Latina/o), rather, it investigates the consequences of what happens when Latina/o students are tracked according to symbolic markers of their ethnic/racial identity, that is, their varying levels of English language competency. Using data from participant observation, semi-structured interviews, students' drawings, as well as free-list and rank-order exercises, I was able to answer the following central research questions: In what ways do the

  1. Distribution-Based Cluster Structure Selection.

    Science.gov (United States)

    Yu, Zhiwen; Zhu, Xianjun; Wong, Hau-San; You, Jane; Zhang, Jun; Han, Guoqiang

    2017-11-01

    The objective of cluster structure ensemble is to find a unified cluster structure from multiple cluster structures obtained from different datasets. Unfortunately, not all the cluster structures contribute to the unified cluster structure. This paper investigates the problem of how to select the suitable cluster structures in the ensemble which will be summarized to a more representative cluster structure. Specifically, the cluster structure is first represented by a mixture of Gaussian distributions, the parameters of which are estimated using the expectation-maximization algorithm. Then, several distribution-based distance functions are designed to evaluate the similarity between two cluster structures. Based on the similarity comparison results, we propose a new approach, which is referred to as the distribution-based cluster structure ensemble (DCSE) framework, to find the most representative unified cluster structure. We then design a new technique, the distribution-based cluster structure selection strategy (DCSSS), to select a subset of cluster structures. Finally, we propose using a distribution-based normalized hypergraph cut algorithm to generate the final result. In our experiments, a nonparametric test is adopted to evaluate the difference between DCSE and its competitors. We adopt 20 real-world datasets obtained from the University of California, Irvine and knowledge extraction based on evolutionary learning repositories, and a number of cancer gene expression profiles to evaluate the performance of the proposed methods. The experimental results show that: 1) DCSE works well on the real-world datasets and 2) DCSE based on DCSSS can further improve the performance of the algorithm.

  2. Towards a unified developments of cluster science

    International Nuclear Information System (INIS)

    Wang Guanghou

    1998-01-01

    In the development of cluster science many concepts and methods have been introduced from nuclear physics, condensed matter physics and quantum chemistry, forming an interdisciplinary field between atomic and molecular physics on the one hand and condensed matter physics on the other hand. Recent achievements in the study of the structures and properties of clusters are reviewed in comparison with those of nuclei and quantum dots

  3. Clustering of correlated networks

    OpenAIRE

    Dorogovtsev, S. N.

    2003-01-01

    We obtain the clustering coefficient, the degree-dependent local clustering, and the mean clustering of networks with arbitrary correlations between the degrees of the nearest-neighbor vertices. The resulting formulas allow one to determine the nature of the clustering of a network.

  4. Cluster knockout reactions

    Indian Academy of Sciences (India)

    2014-04-07

    Apr 7, 2014 ... Cluster knockout reactions are expected to reveal the amount of clustering (such as that of , d and even of heavier clusters such as 12C, 16O etc.) in the target nucleus. In simple terms, incident medium high-energy nuclear projectile interacts strongly with the cluster (present in the target nucleus) as if it ...

  5. What Makes Clusters Decline?

    DEFF Research Database (Denmark)

    Østergaard, Christian Richter; Park, Eun Kyung

    2015-01-01

    Most studies on regional clusters focus on identifying factors and processes that make clusters grow. However, sometimes technologies and market conditions suddenly shift, and clusters decline. This paper analyses the process of decline of the wireless communication cluster in Denmark. The longit...

  6. Measuring Cluster Relaxedness

    Energy Technology Data Exchange (ETDEWEB)

    Moreland, Blythe; /Michigan U. /SLAC

    2012-08-24

    When is a dark matter halo 'relaxed'? In our efforts to understand the structure of the universe, dark matter simulations have provided essential grounds for theoretical predictions. These simulations provide a wealth of ways of parameterizing and measuring the features of astronomical objects. It is these measurements on which we base comparisons of our world and our attempts to re-create it. One of the essential questions dark matter simulations help address is how dark matter halos evolve. How does one characterize different states of that evolution? The focus of this project is identifying cluster relaxedness and how it relates to the internal structure of the halo. A dark matter simulation consists of an N-body simulation which takes an initial set of positions and velocities of the dark matter particles and evolves them under the influence of gravity [6]. Though scientists have so far not been able to detect dark matter particles, the information from these simulations is still valuable especially given the relationship between dark matter halos and galaxy clusters. Galaxies sit within dark matter halos and recent evidence points to filaments of dark matter forming the framework on which galaxy clusters grow [7]. A dark matter halo is a collapsed group of gravitationally bound dark matter particles. Subsets of bound particles form subhalos or substructures. The dark matter simulation is carried out over time - with decreasing redshift (z) or increasing scale factor (a = 1/1+z ). (Thus, z = 0 or a = 1.0 is present-day.) The merger history of a halo can be represented pictorally by a merger tree. A major merger event occurs when a structure joins the main halo with the mass ratio between it and the main halo being above a certain threshold. These events mark important points in the halo's evolution. And it is at these events that one hopes, and perhaps is more likely, to relate measures of relaxedness to this mass accretion. Cluster relaxedness

  7. Clustering in analytical chemistry.

    Science.gov (United States)

    Drab, Klaudia; Daszykowski, Michal

    2014-01-01

    Data clustering plays an important role in the exploratory analysis of analytical data, and the use of clustering methods has been acknowledged in different fields of science. In this paper, principles of data clustering are presented with a direct focus on clustering of analytical data. The role of the clustering process in the analytical workflow is underlined, and its potential impact on the analytical workflow is emphasized.

  8. Creative Clusters in Visegrad Countries: Factors Conditioning Cluster Establishment and Development

    Directory of Open Access Journals (Sweden)

    Bialic-Davendra Magdalena

    2016-06-01

    Full Text Available Since the accession of the Visegrad Group of countries (V4 to the European Union, the importance of clusters has increased. With growing global competitiveness and EU 12 trends, a gradual awareness of creative industries is observed in V4 countries. Therefore, this article analyses creative clusters and factors conditioning their establishment and development. On the basis of a literature review and a questionnaire survey, a mapping of creative clusters was conducted. In addition, catalysts, main motives and key factors in the process of their establishment were identified, as were the activities and factors hampering their development. The scheme of cluster development is presented as the outcome of the qualitative analysis, along with a comparison to findings of other studies. Research findings show that trust building and administrative obstacles are among the main barriers, especially for design clusters and cultural clusters.

  9. Determination of the content of aluminium, manganese, fluorine, lead and cadmium in water for human consumption in a sector of Santa Barbara of Heredia

    International Nuclear Information System (INIS)

    Arias Sanchez, F.

    1995-01-01

    This study developed an analytical procedure dependable and precise, for the determination of manganese and aluminum by means of the technique of Atomic Emission with Plasma Fountain Coupled Inductively (Icp-Aes), and applied to the water that they supply to a sector of the community of Santa Barbara of Heredia. For the determination of aluminum and manganese, the samples showed that they don't need any prior mineralization or preconcentration processing, for which the analysis is rapid and economic. It determined the concentrations of lead and cadmium in the samples, by means of the volt amperometric method of Anodic Spoils with Differential Pulse, and the technique of standard addition for the quantization of the samples. It also determined the concentrations of fluorine by the colorimetric method of SPANDS. (author) [es

  10. Barbara Laborde, De l’enseignement du cinéma à l’éducation aux médias

    OpenAIRE

    Mathy, Adrien

    2017-01-01

    L’éducation aux médias est-elle un effet de mode, ou un projet ambitieux, porteur de multiples promesses ? Qu’auraient à gagner l’enseignement du cinéma et l’éducation aux médias à être, sinon assimilés, du moins rapprochés ? Ces questionnements jalonnent l’ouvrage de Barbara Laborde, dont la contribution déconstruit patiemment les discours sur l’enseignement du cinéma et l’éducation aux médias. Dans ce travail d’envergure, Laborde développe un discours riche, ponctué d’exemples et d’encadrés...

  11. Management of cluster headache

    DEFF Research Database (Denmark)

    Tfelt-Hansen, Peer C; Jensen, Rigmor H

    2012-01-01

    The prevalence of cluster headache is 0.1% and cluster headache is often not diagnosed or misdiagnosed as migraine or sinusitis. In cluster headache there is often a considerable diagnostic delay - an average of 7 years in a population-based survey. Cluster headache is characterized by very severe...... or severe orbital or periorbital pain with a duration of 15-180 minutes. The cluster headache attacks are accompanied by characteristic associated unilateral symptoms such as tearing, nasal congestion and/or rhinorrhoea, eyelid oedema, miosis and/or ptosis. In addition, there is a sense of restlessness...... and agitation. Patients may have up to eight attacks per day. Episodic cluster headache (ECH) occurs in clusters of weeks to months duration, whereas chronic cluster headache (CCH) attacks occur for more than 1 year without remissions. Management of cluster headache is divided into acute attack treatment...

  12. Emigrare o restare in Germania? Tre differenti risposte di autrici ebree tedesche di seconda generazione (Barbara Honigmann, Lea Fleischmann, Esther Dischereit

    Directory of Open Access Journals (Sweden)

    Alessandro Costazza

    2014-04-01

    Full Text Available The purpose of this paper is to investigate, through the analysis of the writings of three German Jewish authors of second generation – Lea Fleischmann, Esther Dischereit and Barbara Honigmann – their different responses to the complex post-war situation of Jews in both West- and East-Germany. Despite the different origins and experiences of their parents under Nazism, all three make in their youth the painful experience of a Judaism lived mainly as absence, as silence about the past and as lack of Jewish tradition and religion. Trying to achieve their own identity, Fleischmann and Dischereit seek a possible integration in post-war West-Germany in the political commitment of the 70s, but must then recognize that anti-Semitism is still widespread in that country. This discovery compels Fleischmann to leave Germany and seek in Israel and eventually in the religion of her fathers a Jewish identity. Esther Dischereit decides on the contrary to perform in Germany her "exercises to be Jewish", assuming the role of critical conscience of German society. Different is the situation of Barbara Honigmann, born and raised in East-Germany, who reacts to the dominant materialism in that state with a need for spirituality that will take her to seek in religion – lived outside of Germany and so far from "negative symbiosis" between Jews and Germans, but also far from Israel - her own diasporic identity. Despite the three different outcomes resulting from the search for Jewish identity in post-war Germany, for all three authors writing plays a crucial function as memory and critical conscience and since this writing is a German one, it imposes eventually a tight and thorough confrontation with German culture.

  13. Comprehensive cluster analysis with Transitivity Clustering.

    Science.gov (United States)

    Wittkop, Tobias; Emig, Dorothea; Truss, Anke; Albrecht, Mario; Böcker, Sebastian; Baumbach, Jan

    2011-03-01

    Transitivity Clustering is a method for the partitioning of biological data into groups of similar objects, such as genes, for instance. It provides integrated access to various functions addressing each step of a typical cluster analysis. To facilitate this, Transitivity Clustering is accessible online and offers three user-friendly interfaces: a powerful stand-alone version, a web interface, and a collection of Cytoscape plug-ins. In this paper, we describe three major workflows: (i) protein (super)family detection with Cytoscape, (ii) protein homology detection with incomplete gold standards and (iii) clustering of gene expression data. This protocol guides the user through the most important features of Transitivity Clustering and takes ∼1 h to complete.

  14. From collisions to clusters

    DEFF Research Database (Denmark)

    Loukonen, Ville; Bork, Nicolai; Vehkamaki, Hanna

    2014-01-01

    The clustering of sulphuric acid with base molecules is one of the main pathways of new-particle formation in the Earth's atmosphere. First step in the clustering process is likely the formation of a (sulphuric acid)1(base)1(water)n cluster. Here, we present results from direct first-principles m......The clustering of sulphuric acid with base molecules is one of the main pathways of new-particle formation in the Earth's atmosphere. First step in the clustering process is likely the formation of a (sulphuric acid)1(base)1(water)n cluster. Here, we present results from direct first...... bridge. In general, water is able to notably stabilise the formed clusters by allocating a fraction of the released clustering energy....

  15. Loose-cluster approximation

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Loose-cluster approximation. Continuous curve Our Theory. Dashed curve Our Simulation. Loose cluster approx. not only. captures -the anomalous. qualitative features but is also,. quantitatively, quite accurate. Notes:

  16. Cluster beam injection

    International Nuclear Information System (INIS)

    Bottiglioni, F.; Coutant, J.; Fois, M.

    1977-11-01

    Areas of possible applications of cluster injection are discussed. The deposition inside the plasma of molecules, issued from the dissociation of the injected clusters, has been computed. Some empirical scaling laws for the penetration are given

  17. Cluster beam injection

    International Nuclear Information System (INIS)

    Bottiglioni, F.; Coutant, J.; Fois, M.

    1978-01-01

    Areas of possible applications of cluster injection are discussed. The deposition inside the plasma of molecules, issued from the dissociation of the injected clusters, has been computed. Some empirical scaling laws for the penetration are given

  18. Cytological Study of Grade 3 Endometrioid Adenocarcinoma of Endometrial Origin: Cytoarchitecture and Features of Cell Clusters Assessed With Endometrial Brushing Cytology--Focusing on a comparison with endometrioid adenocarcinoma Grade 1, 2.

    Science.gov (United States)

    Matsui, Naruaki; Kajiwara, Hiroshi; Morishita, Akihiro; Tsukada, Hitomi; Nakazawa, Kazumi; Miyazawa, Masaki; Mikami, Mikio; Nakamura, Naoya; Sato, Shinkichi

    2015-06-20

    Aim of study was to clarify the cytological characteristics of grade 3 endometrioid adenocarcinoma of endometrial origin (G3 EA) by endometrial brushing cytology. The subjects were 11 patients in whom G3 EA was diagnosed by review of preoperative cytological specimens obtained at our hospital and related institutions between 2000 and 2010. These patients were investigated with respect to the preoperative cytological diagnosis, background changes, cell cluster patterns, and individual cellular findings. Background changes were classified as inflammatory or tumorous, while cell clusters were classified as overlapping cell cluster, sheet-like cell cluster, clump of high dense gland, papillary, or other cell cluster. Cellular findings were investigated by comparing the incidence of squamous and clear cell metaplasia, the nuclear rounding rate, and the nuclear area with the findings in a control group (35 patients with G1-2 EA). Background changes were classified as inflammatory in 63.6% and necrotic in 36.4%. The cell clusters were classified as overlapping cell cluster in 44.8%, cell cluster in 21.7%, clump of high dense gland in 10.0%, papillary in 4.0%, and other cell cluster in 19.5%. The incidence of squamous and clear cell metaplasia was 27.2% and 18.1%, respectively. The mean nuclear rounding rate was 0.97, and the mean nuclear area was 55.98 µm2. Investigation of the cytoarchitecture of G3 EA with endometrial brushing cytology revealed overlapping cell cluster and tumor cells of a relatively uniform size. These findings suggest that it is necessary to recognize that there are differences between the cytological findings of G3 EA and the usual features of G1-2 EA.

  19. Cluster Physics with Merging Galaxy Clusters

    Directory of Open Access Journals (Sweden)

    Sandor M. Molnar

    2016-02-01

    Full Text Available Collisions between galaxy clusters provide a unique opportunity to study matter in a parameter space which cannot be explored in our laboratories on Earth. In the standard LCDM model, where the total density is dominated by the cosmological constant ($Lambda$ and the matter density by cold dark matter (CDM, structure formation is hierarchical, and clusters grow mostly by merging.Mergers of two massive clusters are the most energetic events in the universe after the Big Bang,hence they provide a unique laboratory to study cluster physics.The two main mass components in clusters behave differently during collisions:the dark matter is nearly collisionless, responding only to gravity, while the gas is subject to pressure forces and dissipation, and shocks and turbulenceare developed during collisions. In the present contribution we review the different methods used to derive the physical properties of merging clusters. Different physical processes leave their signatures on different wavelengths, thusour review is based on a multifrequency analysis. In principle, the best way to analyze multifrequency observations of merging clustersis to model them using N-body/HYDRO numerical simulations. We discuss the results of such detailed analyses.New high spatial and spectral resolution ground and space based telescopeswill come online in the near future. Motivated by these new opportunities,we briefly discuss methods which will be feasible in the near future in studying merging clusters.

  20. Minimalist's linux cluster

    International Nuclear Information System (INIS)

    Choi, Chang-Yeong; Kim, Jeong-Hyun; Kim, Seyong

    2004-01-01

    Using barebone PC components and NIC's, we construct a linux cluster which has 2-dimensional mesh structure. This cluster has smaller footprint, is less expensive, and use less power compared to conventional linux cluster. Here, we report our experience in building such a machine and discuss our current lattice project on the machine

  1. Range-clustering queries

    DEFF Research Database (Denmark)

    Abrahamsen, Mikkel; de Berg, Mark; Buchin, Kevin

    2017-01-01

    an optimal k-clustering for S P ∩ Q. We obtain the following results. • We present a general method to compute a (1 + ϵ)-approximation to a range-clustering query, where ϵ > 0 is a parameter that can be specified as part of the query. Our method applies to a large class of clustering problems, including k...

  2. Cosmology with cluster surveys

    Indian Academy of Sciences (India)

    Surveys of clusters of galaxies provide us with a powerful probe of the density and nature of the dark energy. The red-shift distribution of detected clusters is highly sensitive to the dark energy equation of state parameter . Upcoming Sunyaev–Zel'dovich (SZ) surveys would provide us large yields of clusters to very high ...

  3. Cosmology with cluster surveys

    Indian Academy of Sciences (India)

    Cosmology with cluster surveys. SUBHABRATA MAJUMDAR. CITA, University of Toronto, Toronto, ON, M5S 3H8, Canada. E-mail: subha@cita.utoronto.ca. Abstract. Surveys of clusters of galaxies provide us with a powerful probe of the den- sity and nature of the dark energy. The red-shift distribution of detected clusters is.

  4. Structures of Mn clusters

    Indian Academy of Sciences (India)

    Abstract. The geometries of several Mn clusters in the size range Mn13–Mn23 are studied via the generalized gradient approximation to density functional theory. For the 13- and 19-atom clusters, the icosahedral structures are found to be most stable, while for the 15-atom cluster, the bcc structure is more favoured.

  5. Marketing research cluster analysis

    Directory of Open Access Journals (Sweden)

    Marić Nebojša

    2002-01-01

    Full Text Available One area of applications of cluster analysis in marketing is identification of groups of cities and towns with similar demographic profiles. This paper considers main aspects of cluster analysis by an example of clustering 12 cities with the use of Minitab software.

  6. The Durban Auto Cluster

    DEFF Research Database (Denmark)

    Lorentzen, Jochen; Robbins, Glen; Barnes, Justin

    2004-01-01

    The paper describes the formation of the Durban Auto Cluster in the context of trade liberalization. It argues that the improvement of operational competitiveness of firms in the cluster is prominently due to joint action. It tests this proposition by comparing the gains from cluster activities...

  7. Cosmology with cluster surveys

    Indian Academy of Sciences (India)

    Abstract. Surveys of clusters of galaxies provide us with a powerful probe of the den- sity and nature of the dark energy. The red-shift distribution of detected clusters is highly sensitive to the dark energy equation of state parameter w. Upcoming Sunyaev–. Zel'dovich (SZ) surveys would provide us large yields of clusters to ...

  8. Galaxy clusters in simulations of the local Universe: a matter of constraints

    OpenAIRE

    Sorce, Jenny G.; Tempel, Elmo

    2018-01-01

    To study the full formation and evolution history of galaxy clusters and their population, high resolution simulations of the latter are flourishing. However comparing observed clusters to the simulated ones on a one-to-one basis to refine the models and theories down to the details is non trivial. The large variety of clusters limits the comparisons between observed and numerical clusters. Simulations resembling the local Universe down to the cluster scales permit pushing the limit. Simulate...

  9. COCOA: Simulating Observations of Star Cluster Simulations

    Science.gov (United States)

    Askar, Abbas; Giersz, Mirek; Pych, Wojciech; Dalessandro, Emanuele

    2017-03-01

    COCOA (Cluster simulatiOn Comparison with ObservAtions) creates idealized mock photometric observations using results from numerical simulations of star cluster evolution. COCOA is able to present the output of realistic numerical simulations of star clusters carried out using Monte Carlo or N-body codes in a way that is useful for direct comparison with photometric observations. The code can simulate optical observations from simulation snapshots in which positions and magnitudes of objects are known. The parameters for simulating the observations can be adjusted to mimic telescopes of various sizes. COCOA also has a photometry pipeline that can use standalone versions of DAOPHOT (ascl:1104.011) and ALLSTAR to produce photometric catalogs for all observed stars.

  10. Performance Evaluation of Incremental K-means Clustering Algorithm

    OpenAIRE

    Chakraborty, Sanjay; Nagwani, N. K.

    2014-01-01

    The incremental K-means clustering algorithm has already been proposed and analysed in paper [Chakraborty and Nagwani, 2011]. It is a very innovative approach which is applicable in periodically incremental environment and dealing with a bulk of updates. In this paper the performance evaluation is done for this incremental K-means clustering algorithm using air pollution database. This paper also describes the comparison on the performance evaluations between existing K-means clustering and i...

  11. Cluster analysis for applications

    CERN Document Server

    Anderberg, Michael R

    1973-01-01

    Cluster Analysis for Applications deals with methods and various applications of cluster analysis. Topics covered range from variables and scales to measures of association among variables and among data units. Conceptual problems in cluster analysis are discussed, along with hierarchical and non-hierarchical clustering methods. The necessary elements of data analysis, statistics, cluster analysis, and computer implementation are integrated vertically to cover the complete path from raw data to a finished analysis.Comprised of 10 chapters, this book begins with an introduction to the subject o

  12. Excitations in clusters

    International Nuclear Information System (INIS)

    Bertsch, G.F.

    2001-01-01

    Statistical reaction theory is an important tool for understanding dynamic processes in clusters as well as for extracting information about theirs energetics. The author reviews the statistical reaction theory and establishes formulas concerning cluster evaporation rates, electron emission and radiative cooling. The author recalls a number of useful formulas for describing the electromagnetic properties of small particles, generalizes them and applies them in the case of alkali metal clusters and of silver clusters. The author ends discussing carbon structures, going from small clusters and molecules to fullerenes and nano-tubes. (A.C.)

  13. Concurrent conditional clustering of multiple networks: COCONETS.

    Directory of Open Access Journals (Sweden)

    Sabrina Kleessen

    Full Text Available The accumulation of high-throughput data from different experiments has facilitated the extraction of condition-specific networks over the same set of biological entities. Comparing and contrasting of such multiple biological networks is in the center of differential network biology, aiming at determining general and condition-specific responses captured in the network structure (i.e., included associations between the network components. We provide a novel way for comparison of multiple networks based on determining network clustering (i.e., partition into communities which is optimal across the set of networks with respect to a given cluster quality measure. To this end, we formulate the optimization-based problem of concurrent conditional clustering of multiple networks, termed COCONETS, based on the modularity. The solution to this problem is a clustering which depends on all considered networks and pinpoints their preserved substructures. We present theoretical results for special classes of networks to demonstrate the implications of conditionality captured by the COCONETS formulation. As the problem can be shown to be intractable, we extend an existing efficient greedy heuristic and applied it to determine concurrent conditional clusters on coexpression networks extracted from publically available time-resolved transcriptomics data of Escherichia coli under five stresses as well as on metabolite correlation networks from metabolomics data set from Arabidopsis thaliana exposed to eight environmental conditions. We demonstrate that the investigation of the differences between the clustering based on all networks with that obtained from a subset of networks can be used to quantify the specificity of biological responses. While a comparison of the Escherichia coli coexpression networks based on seminal properties does not pinpoint biologically relevant differences, the common network substructures extracted by COCONETS are supported by

  14. A fuzzy logic based clustering strategy for improving vehicular ad ...

    Indian Academy of Sciences (India)

    tions of cluster head selection approaches common performance metrics are utilized such as CH changes, CH stability, etc. But, reasonable comparison of various clustering approaches is a hard task due to lack of scenarios and standard testing processes, therefore standardization and more researches are needed in this ...

  15. Detecting Globular Star Cluster Tidal Streams

    Science.gov (United States)

    Powell, William Lee, Jr.; Wilhelm, Ronald; Lauchner, Adam; McWilliam, Andrew

    2006-10-01

    Globular cluster tidal streams are of interest for what they can tell us of the dynamical evolution of the clusters and of our Galaxy. Recent studies have used photometric and statistical subtraction methods to attempt to separate potential streams from the field stars that contaminate the samples. As our primary method we choose instead to use photometry to select blue stars that match the horizontal branch of the clusters. We then make spectroscopic observations of these candidates to determine their metallicities and radial velocities, which further constrains whether the candidate stars really originated in the cluster. Combining these results with the photometric data offers a better picture of the structure of tidal streams, and allows comparison of detected stars to theoretical predictions. We present preliminary photometric and spectroscopic results. Data obtained at McDonald Observatory, Kitt Peak National Observatory, and Las Campanas Observatory.

  16. Clustering high dimensional data

    DEFF Research Database (Denmark)

    Assent, Ira

    2012-01-01

    for clustering are required. Consequently, recent research has focused on developing techniques and clustering algorithms specifically for high-dimensional data. Still, open research issues remain. Clustering is a data mining task devoted to the automatic grouping of data based on mutual similarity. Each cluster......High-dimensional data, i.e., data described by a large number of attributes, pose specific challenges to clustering. The so-called ‘curse of dimensionality’, coined originally to describe the general increase in complexity of various computational problems as dimensionality increases, is known...... that provide different cluster models and different algorithmic approaches for cluster detection. Common to all approaches is the fact that they require some underlying assessment of similarity between data objects. In this article, we provide an overview of the effects of high-dimensional spaces...

  17. Spatial cluster modelling

    CERN Document Server

    Lawson, Andrew B

    2002-01-01

    Research has generated a number of advances in methods for spatial cluster modelling in recent years, particularly in the area of Bayesian cluster modelling. Along with these advances has come an explosion of interest in the potential applications of this work, especially in epidemiology and genome research. In one integrated volume, this book reviews the state-of-the-art in spatial clustering and spatial cluster modelling, bringing together research and applications previously scattered throughout the literature. It begins with an overview of the field, then presents a series of chapters that illuminate the nature and purpose of cluster modelling within different application areas, including astrophysics, epidemiology, ecology, and imaging. The focus then shifts to methods, with discussions on point and object process modelling, perfect sampling of cluster processes, partitioning in space and space-time, spatial and spatio-temporal process modelling, nonparametric methods for clustering, and spatio-temporal ...

  18. Clusters in nuclei

    CERN Document Server

    Following the pioneering discovery of alpha clustering and of molecular resonances, the field of nuclear clustering is today one of those domains of heavy-ion nuclear physics that faces the greatest challenges, yet also contains the greatest opportunities. After many summer schools and workshops, in particular over the last decade, the community of nuclear molecular physicists has decided to collaborate in producing a comprehensive collection of lectures and tutorial reviews covering the field. This third volume follows the successful Lect. Notes Phys. 818 (Vol. 1) and 848 (Vol. 2), and comprises six extensive lectures covering the following topics:  - Gamma Rays and Molecular Structure - Faddeev Equation Approach for Three Cluster Nuclear Reactions - Tomography of the Cluster Structure of Light Nuclei Via Relativistic Dissociation - Clustering Effects Within the Dinuclear Model : From Light to Hyper-heavy Molecules in Dynamical Mean-field Approach - Clusterization in Ternary Fission - Clusters in Light N...

  19. Modeling Clustered Data with Very Few Clusters.

    Science.gov (United States)

    McNeish, Daniel; Stapleton, Laura M

    2016-01-01

    Small-sample inference with clustered data has received increased attention recently in the methodological literature, with several simulation studies being presented on the small-sample behavior of many methods. However, nearly all previous studies focus on a single class of methods (e.g., only multilevel models, only corrections to sandwich estimators), and the differential performance of various methods that can be implemented to accommodate clustered data with very few clusters is largely unknown, potentially due to the rigid disciplinary preferences. Furthermore, a majority of these studies focus on scenarios with 15 or more clusters and feature unrealistically simple data-generation models with very few predictors. This article, motivated by an applied educational psychology cluster randomized trial, presents a simulation study that simultaneously addresses the extreme small sample and differential performance (estimation bias, Type I error rates, and relative power) of 12 methods to account for clustered data with a model that features a more realistic number of predictors. The motivating data are then modeled with each method, and results are compared. Results show that generalized estimating equations perform poorly; the choice of Bayesian prior distributions affects performance; and fixed effect models perform quite well. Limitations and implications for applications are also discussed.

  20. Cluster assembly in nitrogenase.

    Science.gov (United States)

    Sickerman, Nathaniel S; Rettberg, Lee A; Lee, Chi Chung; Hu, Yilin; Ribbe, Markus W

    2017-05-09

    The versatile enzyme system nitrogenase accomplishes the challenging reduction of N 2 and other substrates through the use of two main metalloclusters. For molybdenum nitrogenase, the catalytic component NifDK contains the [Fe 8 S 7 ]-core P-cluster and a [MoFe 7 S 9 C-homocitrate] cofactor called the M-cluster. These chemically unprecedented metalloclusters play a critical role in the reduction of N 2 , and both originate from [Fe 4 S 4 ] clusters produced by the actions of NifS and NifU. Maturation of P-cluster begins with a pair of these [Fe 4 S 4 ] clusters on NifDK called the P*-cluster. An accessory protein NifZ aids in P-cluster fusion, and reductive coupling is facilitated by NifH in a stepwise manner to form P-cluster on each half of NifDK. For M-cluster biosynthesis, two [Fe 4 S 4 ] clusters on NifB are coupled with a carbon atom in a radical-SAM dependent process, and concomitant addition of a 'ninth' sulfur atom generates the [Fe 8 S 9 C]-core L-cluster. On the scaffold protein NifEN, L-cluster is matured to M-cluster by the addition of Mo and homocitrate provided by NifH. Finally, matured M-cluster in NifEN is directly transferred to NifDK, where a conformational change locks the cofactor in place. Mechanistic insights into these fascinating biosynthetic processes are detailed in this chapter. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  1. AN APPROACH TO REMOVE THE EFFECT OF RANDOM INITIALIZATION FROM FUZZY C-MEANS CLUSTERING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Samarjit Das

    2014-01-01

    Full Text Available Out of the different available fuzzy clustering techniques Bezdek’s Fuzzy C-Means clustering technique is among the most popular ones. Due to the random initialization of the membership values the performance of Fuzzy C-Means clustering technique varies significantly in its different executions. We have tried to remove the effect of random initialization from Fuzzy CMeans clustering technique by using the Subtractive clustering technique of Chiu as a preprocessor to it. We have also provided a comparison of the performance of our method with those of Fuzzy C-Means clustering technique and Subtractive clustering technique.

  2. Agricultural Clusters in the Netherlands

    NARCIS (Netherlands)

    Schouten, M.A.; Heijman, W.J.M.

    2012-01-01

    Michael Porter was the first to use the term cluster in an economic context. He introduced the term in The Competitive Advantage of Nations (1990). The term cluster is also known as business cluster, industry cluster, competitive cluster or Porterian cluster. This article aims at determining and

  3. Clustering by Minimum Cut Hyperplanes.

    Science.gov (United States)

    Hofmeyr, David P

    2017-08-01

    Minimum normalised graph cuts are highly effective ways of partitioning unlabeled data, having been made popular by the success of spectral clustering. This work presents a novel method for learning hyperplane separators which minimise this graph cut objective, when data are embedded in Euclidean space. The optimisation problem associated with the proposed method can be formulated as a sequence of univariate subproblems, in which the optimal hyperplane orthogonal to a given vector is determined. These subproblems can be solved in log-linear time, by exploiting the trivial factorisation of the exponential function. Experimentation suggests that the empirical runtime of the overall algorithm is also log-linear in the number of data. Asymptotic properties of the minimum cut hyperplane, both for a finite sample, and for an increasing sample assumed to arise from an underlying probability distribution are discussed. In the finite sample case the minimum cut hyperplane converges to the maximum margin hyperplane as the scaling parameter is reduced to zero. Applying the proposed methodology, both for fixed scaling, and the large margin asymptotes, is shown to produce high quality clustering models in comparison with state-of-the-art clustering algorithms in experiments using a large collection of benchmark datasets.

  4. Mass functions for eight galactic clusters in the solar neighborhood

    International Nuclear Information System (INIS)

    Francic, S.P.

    1989-01-01

    Mass functions for eight galactic clusters in the solar neighborhood have been obtained. The mass functions have been determined from proper motion membership probabilities and unlike similar investigations, corrected for outlying cluster stars. The membership probabilities have been determined from the joint proper motion and surface density distributions for the field and clusters stars. They have also been corrected for any magnitude dependences. Comparison of the mass functions with the Salpeter IMF shows that the older clusters tend to be deficient in the number of low mass stars, while the younger clusters tend to have more. Analysis of the relaxation times shows that the deficiency of faint stars in the older clusters is likely due to their evaporation from the cluster. The combined mass function for six of the cluster results in a power law with a power law index of -1.97 ± 0.17 for 1.1 < M/Mass of sun < 2.5. This agrees with a recent determination of the field star IMF where the power law index is -2.00 ± 0.18 for 0.8 < M/Mass of sun < 18. If the older clusters are not considered, then comparison of the combined mass function with the individual cluster mass functions shows that the universality hypothesis cannot be denied

  5. Open source clustering software.

    Science.gov (United States)

    de Hoon, M J L; Imoto, S; Nolan, J; Miyano, S

    2004-06-12

    We have implemented k-means clustering, hierarchical clustering and self-organizing maps in a single multipurpose open-source library of C routines, callable from other C and C++ programs. Using this library, we have created an improved version of Michael Eisen's well-known Cluster program for Windows, Mac OS X and Linux/Unix. In addition, we generated a Python and a Perl interface to the C Clustering Library, thereby combining the flexibility of a scripting language with the speed of C. The C Clustering Library and the corresponding Python C extension module Pycluster were released under the Python License, while the Perl module Algorithm::Cluster was released under the Artistic License. The GUI code Cluster 3.0 for Windows, Macintosh and Linux/Unix, as well as the corresponding command-line program, were released under the same license as the original Cluster code. The complete source code is available at http://bonsai.ims.u-tokyo.ac.jp/mdehoon/software/cluster. Alternatively, Algorithm::Cluster can be downloaded from CPAN, while Pycluster is also available as part of the Biopython distribution.

  6. Post-irradiation Examination Plan for ORNL and University of California Santa Barbara Assessment of UCSB ATR-2 Irradiation Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Nanstad, R. K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yamamoto, T. [Univ. of California, Santa Barbara, CA (United States); Sokolov, M. A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-01-25

    New and existing databases will be combined to support development of physically based models of transition temperature shifts (TTS) for high fluence-low flux (φ < 1011n/cm2-s) conditions, beyond the existing surveillance database, to neutron fluences of at least 1×1020 n/cm2 (>1 MeV). All references to neutron flux and fluence in this report are for fast neutrons (>1 MeV). The reactor pressure vessel (RPV) task of the Light Water Reactor Sustainability (LWRS) Program is working with various organizations to obtain archival surveillance materials from commercial nuclear power plants to allow for comparisons of the irradiation-induced microstructural features from reactor surveillance materials with those from similar materials irradiated under high flux conditions in test reactors

  7. Cluster Management Institutionalization

    DEFF Research Database (Denmark)

    Normann, Leo; Agger Nielsen, Jeppe

    2015-01-01

    This article explores a new management form – cluster management – in Danish public sector day care. Although cluster management has been widely adopted in Danish day care at the municipality level, it has attracted only sparse research attention. We use theoretical insights from Scandinavian...... institutionalism together with a longitudinal case-based inquiry into how cluster management has entered and penetrated the management practices of day care in Denmark. We demonstrate how cluster management became widely adopted in the day care field not only because of its intrinsic properties but also because...... of how it was legitimized as a “ready-to-use” management model. Further, our account reveals how cluster management translated into considerably different local variants as it travelled into specific organizations. However, these processes have not occurred sequentially with cluster management first...

  8. Disentangling Porterian Clusters

    DEFF Research Database (Denmark)

    Jagtfelt, Tue

    This dissertation investigates the contemporary phenomenon of industrial clusters based on the work of Michael E. Porter, the central progenitor and promoter of the cluster notion. The dissertation pursues two central questions: 1) What is a cluster? and 2) How could Porter’s seemingly fuzzy...... to his membership on the Commission on Industrial Competitiveness, and that the cluster notion found in his influential book, Nations, represents a significant shift in his conception of cluster compared with his early conceptions. This shift, it is argued, is a deliberate attempt by Porter to create...... a paradigmatic textbook that follows Kuhn’s blueprint for scientific revolutions by instilling Nations with circular references and thus creating a local linguistic holism conceptualized through an encompassing notion of cluster. The dissertation concludes that the two research questions are philosophically...

  9. BioCluster: Tool for Identification and Clustering of Enterobacteriaceae Based on Biochemical Data

    Directory of Open Access Journals (Sweden)

    Ahmed Abdullah

    2015-06-01

    Full Text Available Presumptive identification of different Enterobacteriaceae species is routinely achieved based on biochemical properties. Traditional practice includes manual comparison of each biochemical property of the unknown sample with known reference samples and inference of its identity based on the maximum similarity pattern with the known samples. This process is labor-intensive, time-consuming, error-prone, and subjective. Therefore, automation of sorting and similarity in calculation would be advantageous. Here we present a MATLAB-based graphical user interface (GUI tool named BioCluster. This tool was designed for automated clustering and identification of Enterobacteriaceae based on biochemical test results. In this tool, we used two types of algorithms, i.e., traditional hierarchical clustering (HC and the Improved Hierarchical Clustering (IHC, a modified algorithm that was developed specifically for the clustering and identification of Enterobacteriaceae species. IHC takes into account the variability in result of 1–47 biochemical tests within this Enterobacteriaceae family. This tool also provides different options to optimize the clustering in a user-friendly way. Using computer-generated synthetic data and some real data, we have demonstrated that BioCluster has high accuracy in clustering and identifying enterobacterial species based on biochemical test data. This tool can be freely downloaded at http://microbialgen.du.ac.bd/biocluster/.

  10. BioCluster: tool for identification and clustering of Enterobacteriaceae based on biochemical data.

    Science.gov (United States)

    Abdullah, Ahmed; Sabbir Alam, S M; Sultana, Munawar; Hossain, M Anwar

    2015-06-01

    Presumptive identification of different Enterobacteriaceae species is routinely achieved based on biochemical properties. Traditional practice includes manual comparison of each biochemical property of the unknown sample with known reference samples and inference of its identity based on the maximum similarity pattern with the known samples. This process is labor-intensive, time-consuming, error-prone, and subjective. Therefore, automation of sorting and similarity in calculation would be advantageous. Here we present a MATLAB-based graphical user interface (GUI) tool named BioCluster. This tool was designed for automated clustering and identification of Enterobacteriaceae based on biochemical test results. In this tool, we used two types of algorithms, i.e., traditional hierarchical clustering (HC) and the Improved Hierarchical Clustering (IHC), a modified algorithm that was developed specifically for the clustering and identification of Enterobacteriaceae species. IHC takes into account the variability in result of 1-47 biochemical tests within this Enterobacteriaceae family. This tool also provides different options to optimize the clustering in a user-friendly way. Using computer-generated synthetic data and some real data, we have demonstrated that BioCluster has high accuracy in clustering and identifying enterobacterial species based on biochemical test data. This tool can be freely downloaded at http://microbialgen.du.ac.bd/biocluster/. Copyright © 2015 The Authors. Production and hosting by Elsevier Ltd.. All rights reserved.

  11. THE QUESTIONNAIRE ON SOCIOCULTURAL CONTEXT IN EATING DISORDERS DEVELOPED BY MACIEJ PILECKI AND BARBARA JÓZEFIK - A SUMMARY OF THE CURRENT STAGE OF WORK ON THE RESEARCH INSTRUMENT

    OpenAIRE

    Pilecki, Maciej; Sałapa, Kinga; Józefik, Barbara; Kozłowska-Jasnos, Małgorzata

    2014-01-01

    Aim. To create the most coherent version of the scales of The Questionnaire on Sociocultural Context developed by Maciej Pilecki and Barbara Józefik and to assess the relationship that they have with disordered eating and eating disorders. Method. Firstly, a factor analysis on selected items of the research instrument based on a population of 614 girls attending Krakow schools was conducted. Then, in the same group, an analysis of the relationship between the obtained factors and ...

  12. Geomorphological and geochemical characterization of the 11 August 2008 mud volcano eruption at S. Barbara village (Sicily, Italy and its possible relationship with seismic activity

    Directory of Open Access Journals (Sweden)

    P. Madonia

    2011-05-01

    Full Text Available On 11 August 2008 a paroxysmal eruption occurred at Santa Barbara mud volcano (MV, located close to Caltanissetta, one of the most densely populated cities of Sicily (Italy. An associated minor event took place on August 2009. Both the events caused severe damage to civil infrastructures located within a range of about 2 km from the eruptive vent. Geomorphological, geochemical, and seismological investigations were carried out for framing the events in the appropriate geodynamic context. Geomorphological surveys recognized, in the immediate surrounding of the main emission point, two different families of processes and landforms: (i ground deformations and (ii changes in morphology and number of the fluid emitting vents. These processes were associated to a wider network of fractures, seemingly generated by the shock wave produced by the gas blast that occurred at the main paroxysm. Geochemical characterization allowed an estimation of the source of the fluids, or at least their last standing, at about 3 km depth. Finally, the close time relationships observed between anomalous increments of seismic activity and the two main paroxysmal events accounted for a possible common trigger for both the phenomena, even with different timing due to the very different initial conditions and characteristics of the two processes, i.e. seismogenesis and gas overloading.

  13. Orientalism Reconsidered: Turkey in Barbara Frischmuth's Das Verschwinden des Schattens in der Sonne and Hanne Mede-Flock's Im Schatten der Mondsichel

    Directory of Open Access Journals (Sweden)

    Petra Fachinger

    1999-06-01

    Full Text Available Recent German criticism has demonstrated that the relationships of Austria and Germany with the "Orient" have been more complex than Edward Said's Orientalism makes it appear. Furthermore, Said only touches upon gender issues. Studies like Rana Kabbani's Europe's Myths of Orient: Devise and Rule explore the convergence of race, class, and gender in the conceptualization of the "Orient." Kabbani claims that in Elias Canetti's Die Stimmen von Marrakesch the narrator's identification with the colonizer's position enters into his representation of self as much as does his gender. My essay demonstrates how the Austrian writer Barbara Frischmuth and the German writer Hanne Mede-Flock represent their female protagonists' interaction with the "Orient" as more complex and less "colonizing" than that of Canetti's narrator. While Frischmuth rewrites the Bildungsroman to subvert Eurocentric assumptions underlying travel literature, Mede-Flock goes one step further by taking the focus away from the individual protagonist and intellectual life in the city, and by representing the encounter with Turkey as political. However, Turkey remains a Eurocentric construct in the two novels, and their authors, by attempting to undermine some cultural stereotypes, unwittingly reinforce others.

  14. Ativismo artístico: engajamento político e questões de gênero na obra de Barbara Kruger

    Directory of Open Access Journals (Sweden)

    Lina Alves Arruda

    2011-01-01

    Full Text Available http://dx.doi.org/10.1590/S0104-026X2011000200005 O presente artigo introduz e contextualiza as primeiras manifestações feministas que compuseram o panorama artístico do final da década de 1960 até 1980. São analisadas as circunstâncias históricas (incluindo a história da arte que facilitaram a ponte entre as esferas da arte e da política, bem como os problemas formais e estéticos que a prática artística ativista apresentou e sua recepção como movimento. Para tanto, nos basearemos no trabalho da artista norte-americana Barbara Kruger, que produziu obras fundamentais para a consolidação da arte feminista, abordando criticamente uma ampla variedade de temas relacionados à mulher (violência, aborto, identidade, papel social, estética. O conteúdo das obras de Kruger está em sintonia com importantes circunstâncias políticas e temas sociais  contemporâneos à sua produção e estabelece relação direta com teorias feministas da época, permitindo uma análise do contexto artístico e sócio-político do período.

  15. Geomorphological and geochemical characterization of the 11 August 2008 mud volcano eruption at S. Barbara village (Sicily, Italy) and its possible relationship with seismic activity

    Science.gov (United States)

    Madonia, P.; Grassa, F.; Cangemi, M.; Musumeci, C.

    2011-05-01

    On 11 August 2008 a paroxysmal eruption occurred at Santa Barbara mud volcano (MV), located close to Caltanissetta, one of the most densely populated cities of Sicily (Italy). An associated minor event took place on August 2009. Both the events caused severe damage to civil infrastructures located within a range of about 2 km from the eruptive vent. Geomorphological, geochemical, and seismological investigations were carried out for framing the events in the appropriate geodynamic context. Geomorphological surveys recognized, in the immediate surrounding of the main emission point, two different families of processes and landforms: (i) ground deformations and (ii) changes in morphology and number of the fluid emitting vents. These processes were associated to a wider network of fractures, seemingly generated by the shock wave produced by the gas blast that occurred at the main paroxysm. Geochemical characterization allowed an estimation of the source of the fluids, or at least their last standing, at about 3 km depth. Finally, the close time relationships observed between anomalous increments of seismic activity and the two main paroxysmal events accounted for a possible common trigger for both the phenomena, even with different timing due to the very different initial conditions and characteristics of the two processes, i.e. seismogenesis and gas overloading.

  16. 15th Cluster workshop

    CERN Document Server

    Laakso, Harri; Escoubet, C. Philippe; The Cluster Active Archive : Studying the Earth’s Space Plasma Environment

    2010-01-01

    Since the year 2000 the ESA Cluster mission has been investigating the small-scale structures and processes of the Earth's plasma environment, such as those involved in the interaction between the solar wind and the magnetospheric plasma, in global magnetotail dynamics, in cross-tail currents, and in the formation and dynamics of the neutral line and of plasmoids. This book contains presentations made at the 15th Cluster workshop held in March 2008. It also presents several articles about the Cluster Active Archive and its datasets, a few overview papers on the Cluster mission, and articles reporting on scientific findings on the solar wind, the magnetosheath, the magnetopause and the magnetotail.

  17. How atomic nuclei cluster.

    Science.gov (United States)

    Ebran, J-P; Khan, E; Nikšić, T; Vretenar, D

    2012-07-18

    Nucleonic matter displays a quantum-liquid structure, but in some cases finite nuclei behave like molecules composed of clusters of protons and neutrons. Clustering is a recurrent feature in light nuclei, from beryllium to nickel. Cluster structures are typically observed as excited states close to the corresponding decay threshold; the origin of this phenomenon lies in the effective nuclear interaction, but the detailed mechanism of clustering in nuclei has not yet been fully understood. Here we use the theoretical framework of energy-density functionals, encompassing both cluster and quantum liquid-drop aspects of nuclei, to show that conditions for cluster formation can in part be traced back to the depth of the confining nuclear potential. For the illustrative example of neon-20, we show that the depth of the potential determines the energy spacings between single-nucleon orbitals in deformed nuclei, the localization of the corresponding wavefunctions and, therefore, the degree of nucleonic density clustering. Relativistic functionals, in particular, are characterized by deep single-nucleon potentials. When compared to non-relativistic functionals that yield similar ground-state properties (binding energy, deformation, radii), they predict the occurrence of much more pronounced cluster structures. More generally, clustering is considered as a transitional phenomenon between crystalline and quantum-liquid phases of fermionic systems.

  18. Finite-temperature quantum simulations of mixed rare gas clusters.

    Science.gov (United States)

    Meuwly, Markus; Doll, J D

    2010-06-21

    Finite-temperature quantum Monte Carlo simulations are presented for mixed neon/argon rare gas clusters containing up to n=10 atoms. For the smallest clusters (n=3) comparison with rigorous bound state calculations and experiments shows that the present approach is accurate to within fractions of wavenumbers for energies and to within a few percent or better for rotational constants. For larger cluster sizes, for which no rigorous quantum calculations are available, comparison with experiment becomes even more favorable. In all simulations accurate pair potentials for the rare gas-rare gas interactions are employed and comparison with high-level electronic structure calculations suggest that many-body interactions play a minor role. For the largest clusters investigated (Ne(4)Ar(6)) gradual melting of the neon phase is observed while the argon-phase remains structurally intact.

  19. Statistical properties of convex clustering

    OpenAIRE

    Tan, Kean Ming; Witten, Daniela

    2015-01-01

    In this manuscript, we study the statistical properties of convex clustering. We establish that convex clustering is closely related to single linkage hierarchical clustering and $k$-means clustering. In addition, we derive the range of the tuning parameter for convex clustering that yields a non-trivial solution. We also provide an unbiased estimator of the degrees of freedom, and provide a finite sample bound for the prediction error for convex clustering. We compare convex clustering to so...

  20. Nonlocalized clustering and evolution of cluster structure in nuclei

    Science.gov (United States)

    Horiuchi, H.

    2017-06-01

    It is shown that the THSR (Tohsaki-Horiuchi-Schuck-Roepke) wave function describe well not only cluster-gas like structures but also ordinary cluster structures with spatial localization of clusters. Based on this fact, the container model has been proposed as a new model of cluster dynamics. For better description of cluster dynamics, extended version of container model has been introduced. The container model of cluster dynamics teaches us how is the evolution of cluster structure which starts from the ground state having shell-model structure to many kinds of cluster states up to the cluster-gas states.

  1. Message Passing Framework for Globally Interconnected Clusters

    International Nuclear Information System (INIS)

    Hafeez, M; Riaz, N; Asghar, S; Malik, U A; Rehman, A

    2011-01-01

    In prevailing technology trends it is apparent that the network requirements and technologies will advance in future. Therefore the need of High Performance Computing (HPC) based implementation for interconnecting clusters is comprehensible for scalability of clusters. Grid computing provides global infrastructure of interconnecting clusters consisting of dispersed computing resources over Internet. On the other hand the leading model for HPC programming is Message Passing Interface (MPI). As compared to Grid computing, MPI is better suited for solving most of the complex computational problems. MPI itself is restricted to a single cluster. It does not support message passing over the internet to use the computing resources of different clusters in an optimal way. We propose a model that provides message passing capabilities between parallel applications over the internet. The proposed model is based on Architecture for Java Universal Message Passing (A-JUMP) framework and Enterprise Service Bus (ESB) named as High Performance Computing Bus. The HPC Bus is built using ActiveMQ. HPC Bus is responsible for communication and message passing in an asynchronous manner. Asynchronous mode of communication offers an assurance for message delivery as well as a fault tolerance mechanism for message passing. The idea presented in this paper effectively utilizes wide-area intercluster networks. It also provides scheduling, dynamic resource discovery and allocation, and sub-clustering of resources for different jobs. Performance analysis and comparison study of the proposed framework with P2P-MPI are also presented in this paper.

  2. Message Passing Framework for Globally Interconnected Clusters

    Science.gov (United States)

    Hafeez, M.; Asghar, S.; Malik, U. A.; Rehman, A.; Riaz, N.

    2011-12-01

    In prevailing technology trends it is apparent that the network requirements and technologies will advance in future. Therefore the need of High Performance Computing (HPC) based implementation for interconnecting clusters is comprehensible for scalability of clusters. Grid computing provides global infrastructure of interconnecting clusters consisting of dispersed computing resources over Internet. On the other hand the leading model for HPC programming is Message Passing Interface (MPI). As compared to Grid computing, MPI is better suited for solving most of the complex computational problems. MPI itself is restricted to a single cluster. It does not support message passing over the internet to use the computing resources of different clusters in an optimal way. We propose a model that provides message passing capabilities between parallel applications over the internet. The proposed model is based on Architecture for Java Universal Message Passing (A-JUMP) framework and Enterprise Service Bus (ESB) named as High Performance Computing Bus. The HPC Bus is built using ActiveMQ. HPC Bus is responsible for communication and message passing in an asynchronous manner. Asynchronous mode of communication offers an assurance for message delivery as well as a fault tolerance mechanism for message passing. The idea presented in this paper effectively utilizes wide-area intercluster networks. It also provides scheduling, dynamic resource discovery and allocation, and sub-clustering of resources for different jobs. Performance analysis and comparison study of the proposed framework with P2P-MPI are also presented in this paper.

  3. Lifting to cluster-tilting objects in higher cluster categories

    OpenAIRE

    Liu, Pin

    2008-01-01

    In this note, we consider the $d$-cluster-tilted algebras, the endomorphism algebras of $d$-cluster-tilting objects in $d$-cluster categories. We show that a tilting module over such an algebra lifts to a $d$-cluster-tilting object in this $d$-cluster category.

  4. Application of cluster analysis and unsupervised learning to multivariate tissue characterization

    International Nuclear Information System (INIS)

    Momenan, R.; Insana, M.F.; Wagner, R.F.; Garra, B.S.; Loew, M.H.

    1987-01-01

    This paper describes a procedure for classifying tissue types from unlabeled acoustic measurements (data type unknown) using unsupervised cluster analysis. These techniques are being applied to unsupervised ultrasonic image segmentation and tissue characterization. The performance of a new clustering technique is measured and compared with supervised methods, such as a linear Bayes classifier. In these comparisons two objectives are sought: a) How well does the clustering method group the data?; b) Do the clusters correspond to known tissue classes? The first question is investigated by a measure of cluster similarity and dispersion. The second question involves a comparison with a supervised technique using labeled data

  5. Mixed-Initiative Clustering

    Science.gov (United States)

    Huang, Yifen

    2010-01-01

    Mixed-initiative clustering is a task where a user and a machine work collaboratively to analyze a large set of documents. We hypothesize that a user and a machine can both learn better clustering models through enriched communication and interactive learning from each other. The first contribution or this thesis is providing a framework of…

  6. Securing Personal Network Clusters

    NARCIS (Netherlands)

    Jehangir, A.; Heemstra de Groot, S.M.

    2007-01-01

    A Personal Network is a self-organizing, secure and private network of a user’s devices notwithstanding their geographic location. It aims to utilize pervasive computing to provide users with new and improved services. In this paper we propose a model for securing Personal Network clusters. Clusters

  7. Calixarene-supported clusters

    DEFF Research Database (Denmark)

    Taylor, Stephanie M.; McIntosh, Ruaraidh D.; Piligkos, Stergios

    2012-01-01

    A combination of complementary cluster ligands results in the formation of a new calixarene-supported ferromagnetic [Mn(5)] cage that displays the characteristic bonding modes of each support.......A combination of complementary cluster ligands results in the formation of a new calixarene-supported ferromagnetic [Mn(5)] cage that displays the characteristic bonding modes of each support....

  8. Reflections on cluster policies

    NARCIS (Netherlands)

    Brakman, Steven; van Marrewijk, Charles

    Economic activity tends to cluster. This results in productivity gains. For policy makers this offers an opportunity to formulate and promote policies that foster clustering of economic activity. Paradoxically, although agglomeration rents are often found in empirical research, a rationale for

  9. When Clusters become Networks

    NARCIS (Netherlands)

    S.M.W. Phlippen (Sandra); G.A. van der Knaap (Bert)

    2007-01-01

    textabstractPolicy makers spend large amounts of public resources on the foundation of science parks and other forms of geographically clustered business activities, in order to stimulate regional innovation. Underlying the relation between clusters and innovation is the assumption that co-located

  10. Fuzzy clustering of mechanisms

    Indian Academy of Sciences (India)

    type synthesis phase of mechanical design. To the best of the authors' knowledge, this type of clustering of mechanisms has not been attempted before. Thus, this is the first attempt to cluster the mechanisms based on some quantitative measures. It may help the engineers to carry out type synthesis of the mechanisms.

  11. Neurostimulation in cluster headache

    DEFF Research Database (Denmark)

    Pedersen, Jeppe L; Barloese, Mads; Jensen, Rigmor H

    2013-01-01

    PURPOSE OF REVIEW: Neurostimulation has emerged as a viable treatment for intractable chronic cluster headache. Several therapeutic strategies are being investigated including stimulation of the hypothalamus, occipital nerves and sphenopalatine ganglion. The aim of this review is to provide...... effective strategy must be preferred as first-line therapy for intractable chronic cluster headache....

  12. CSR in Industrial Clusters

    DEFF Research Database (Denmark)

    Lund-Thomsen, Peter; Pillay, Renginee G.

    2012-01-01

    development in the South. At the turn of the millennium the industrial cluster debate expanded as clusters were perceived as a potential source of poverty reduction, while their role in promoting CSR among small and medium-sized enterprises began to take shape from 2006 onwards. At present, there is still...

  13. Cluster knockout reactions

    Indian Academy of Sciences (India)

    2014-04-07

    Apr 7, 2014 ... advancements in the area of (α, 2α) reactions and heavy cluster knockout reactions are discussed. Importance of the finite-range vertex and the final-state interactions are brought out. Keywords. Cluster knockout reactions; FR-DWIA calculations; t-matrix effective interaction. PACS Nos 14.20.Pt; 24.10.

  14. Multilevel functional clustering analysis.

    Science.gov (United States)

    Serban, Nicoleta; Jiang, Huijing

    2012-09-01

    In this article, we investigate clustering methods for multilevel functional data, which consist of repeated random functions observed for a large number of units (e.g., genes) at multiple subunits (e.g., bacteria types). To describe the within- and between variability induced by the hierarchical structure in the data, we take a multilevel functional principal component analysis (MFPCA) approach. We develop and compare a hard clustering method applied to the scores derived from the MFPCA and a soft clustering method using an MFPCA decomposition. In a simulation study, we assess the estimation accuracy of the clustering membership and the cluster patterns under a series of settings: small versus moderate number of time points; various noise levels; and varying number of subunits per unit. We demonstrate the applicability of the clustering analysis to a real data set consisting of expression profiles from genes activated by immunity system cells. Prevalent response patterns are identified by clustering the expression profiles using our multilevel clustering analysis. © 2012, The International Biometric Society.

  15. Cluster Synchronization Algorithms

    NARCIS (Netherlands)

    Xia, Weiguo; Cao, Ming

    2010-01-01

    This paper presents two approaches to achieving cluster synchronization in dynamical multi-agent systems. In contrast to the widely studied synchronization behavior, where all the coupled agents converge to the same value asymptotically, in the cluster synchronization problem studied in this paper,

  16. Fuzzy clustering of mechanisms

    Indian Academy of Sciences (India)

    two clustering techniques, the mechanisms have been classified in the present work and in future, it may be extended to develop an expert system, which can automate type synthesis phase of mechanical design. To the best of the authors' knowledge, this type of clustering of mechanisms has not been attempted before.

  17. Collisions between Globular Clusters

    Science.gov (United States)

    Belloni, D. T.; Rocha-Pinto, H. J.

    2014-10-01

    The study of globular clusters (GC) plays an important role in our understanding of the Universe since these systems are true laboratories for theories of stellar dynamics and evolution. We are interested in studying a globular cluster formed by a collision between two different GC with NBODY6 (Aarseth, 2003). Firstly, in order to understand this code, we analyse how tidal streams form from a globular cluster in a circular orbit (on the disk) around the center of the Milky Way. In the next stage of this work we will study that collision. The stellar escape or capture from globular cluster can be understood with the Restricted Three Body Problem. These stars escape in a chaotic orbit, and in some cases may return (again in a chaotic orbit) to the cluster due to the Galactic potential. In most cases, such stars quickly alter their escape chaotic orbits to orbits that are similar to the parent cluster's orbit. Our results show an agglomeration of stars in a normal direction related to the direction towards the center of the Milky Way, forming thus a stream. We can explain this considering that a circular orbit around the dominant potential is the most likely orbit, since it requires minimum energy. In this coordinate systems, the tidal tails (or streams) rotates around the cluster center with the same mean motion associated to cluster around the Milky Way center.

  18. Detecting clusters of mutations.

    Directory of Open Access Journals (Sweden)

    Tong Zhou

    Full Text Available Positive selection for protein function can lead to multiple mutations within a small stretch of DNA, i.e., to a cluster of mutations. Recently, Wagner proposed a method to detect such mutation clusters. His method, however, did not take into account that residues with high solvent accessibility are inherently more variable than residues with low solvent accessibility. Here, we propose a new algorithm to detect clustered evolution. Our algorithm controls for different substitution probabilities at buried and exposed sites in the tertiary protein structure, and uses random permutations to calculate accurate P values for inferred clusters. We apply the algorithm to genomes of bacteria, fly, and mammals, and find several clusters of mutations in functionally important regions of proteins. Surprisingly, clustered evolution is a relatively rare phenomenon. Only between 2% and 10% of the genes we analyze contain a statistically significant mutation cluster. We also find that not controlling for solvent accessibility leads to an excess of clusters in terminal and solvent-exposed regions of proteins. Our algorithm provides a novel method to identify functionally relevant divergence between groups of species. Moreover, it could also be useful to detect artifacts in automatically assembled genomes.

  19. Alpha clustering in nuclei

    International Nuclear Information System (INIS)

    Hodgson, P.E.

    1990-01-01

    The effects of nucleon clustering in nuclei are described, with reference to both nuclear structure and nuclear reactions, and the advantages of using the cluster formalism to describe a range of phenomena are discussed. It is shown that bound and scattering alpha-particle states can be described in a unified way using an energy-dependent alpha-nucleus potential. (author)

  20. Mathematical classification and clustering

    CERN Document Server

    Mirkin, Boris

    1996-01-01

    I am very happy to have this opportunity to present the work of Boris Mirkin, a distinguished Russian scholar in the areas of data analysis and decision making methodologies. The monograph is devoted entirely to clustering, a discipline dispersed through many theoretical and application areas, from mathematical statistics and combina­ torial optimization to biology, sociology and organizational structures. It compiles an immense amount of research done to date, including many original Russian de­ velopments never presented to the international community before (for instance, cluster-by-cluster versions of the K-Means method in Chapter 4 or uniform par­ titioning in Chapter 5). The author's approach, approximation clustering, allows him both to systematize a great part of the discipline and to develop many in­ novative methods in the framework of optimization problems. The optimization methods considered are proved to be meaningful in the contexts of data analysis and clustering. The material presented in ...

  1. Negotiating Cluster Boundaries

    DEFF Research Database (Denmark)

    Giacomin, Valeria

    2017-01-01

    Palm oil was introduced to Malay(si)a as an alternative to natural rubber, inheriting its cluster organizational structure. In the late 1960s, Malaysia became the world’s largest palm oil exporter. Based on archival material from British colonial institutions and agency houses, this paper focuses...... on the governance dynamics that drove institutional change within this cluster during decolonization. The analysis presents three main findings: (i) cluster boundaries are defined by continuous tug-of-war style negotiations between public and private actors; (ii) this interaction produces institutional change...... within the cluster, in the form of cumulative ‘institutional rounds’ – the correction or disruption of existing institutions or the creation of new ones; and (iii) this process leads to a broader inclusion of local actors in the original cluster configuration. The paper challenges the prevalent argument...

  2. The anterior hypothalamus in cluster headache.

    Science.gov (United States)

    Arkink, Enrico B; Schmitz, Nicole; Schoonman, Guus G; van Vliet, Jorine A; Haan, Joost; van Buchem, Mark A; Ferrari, Michel D; Kruit, Mark C

    2017-10-01

    Objective To evaluate the presence, localization, and specificity of structural hypothalamic and whole brain changes in cluster headache and chronic paroxysmal hemicrania (CPH). Methods We compared T1-weighted magnetic resonance images of subjects with cluster headache (episodic n = 24; chronic n = 23; probable n = 14), CPH ( n = 9), migraine (with aura n = 14; without aura n = 19), and no headache ( n = 48). We applied whole brain voxel-based morphometry (VBM) using two complementary methods to analyze structural changes in the hypothalamus: region-of-interest analyses in whole brain VBM, and manual segmentation of the hypothalamus to calculate volumes. We used both conservative VBM thresholds, correcting for multiple comparisons, and less conservative thresholds for exploratory purposes. Results Using region-of-interest VBM analyses mirrored to the headache side, we found enlargement ( p cluster headache compared to controls, and in all participants with episodic or chronic cluster headache taken together compared to migraineurs. After manual segmentation, hypothalamic volume (mean±SD) was larger ( p cluster headache compared to controls (1.72 ± 0.15 ml) and migraineurs (1.68 ± 0.19 ml). Similar but non-significant trends were observed for participants with probable cluster headache (1.82 ± 0.19 ml; p = 0.07) and CPH (1.79 ± 0.20 ml; p = 0.15). Increased hypothalamic volume was primarily explained by bilateral enlargement of the anterior hypothalamus. Exploratory whole brain VBM analyses showed widespread changes in pain-modulating areas in all subjects with headache. Interpretation The anterior hypothalamus is enlarged in episodic and chronic cluster headache and possibly also in probable cluster headache or CPH, but not in migraine.

  3. Searching remote homology with spectral clustering with symmetry in neighborhood cluster kernels.

    Directory of Open Access Journals (Sweden)

    Ujjwal Maulik

    Full Text Available Remote homology detection among proteins utilizing only the unlabelled sequences is a central problem in comparative genomics. The existing cluster kernel methods based on neighborhoods and profiles and the Markov clustering algorithms are currently the most popular methods for protein family recognition. The deviation from random walks with inflation or dependency on hard threshold in similarity measure in those methods requires an enhancement for homology detection among multi-domain proteins. We propose to combine spectral clustering with neighborhood kernels in Markov similarity for enhancing sensitivity in detecting homology independent of "recent" paralogs. The spectral clustering approach with new combined local alignment kernels more effectively exploits the unsupervised protein sequences globally reducing inter-cluster walks. When combined with the corrections based on modified symmetry based proximity norm deemphasizing outliers, the technique proposed in this article outperforms other state-of-the-art cluster kernels among all twelve implemented kernels. The comparison with the state-of-the-art string and mismatch kernels also show the superior performance scores provided by the proposed kernels. Similar performance improvement also is found over an existing large dataset. Therefore the proposed spectral clustering framework over combined local alignment kernels with modified symmetry based correction achieves superior performance for unsupervised remote homolog detection even in multi-domain and promiscuous domain proteins from Genolevures database families with better biological relevance. Source code available upon request.sarkar@labri.fr.

  4. Searching remote homology with spectral clustering with symmetry in neighborhood cluster kernels.

    Science.gov (United States)

    Maulik, Ujjwal; Sarkar, Anasua

    2013-01-01

    Remote homology detection among proteins utilizing only the unlabelled sequences is a central problem in comparative genomics. The existing cluster kernel methods based on neighborhoods and profiles and the Markov clustering algorithms are currently the most popular methods for protein family recognition. The deviation from random walks with inflation or dependency on hard threshold in similarity measure in those methods requires an enhancement for homology detection among multi-domain proteins. We propose to combine spectral clustering with neighborhood kernels in Markov similarity for enhancing sensitivity in detecting homology independent of "recent" paralogs. The spectral clustering approach with new combined local alignment kernels more effectively exploits the unsupervised protein sequences globally reducing inter-cluster walks. When combined with the corrections based on modified symmetry based proximity norm deemphasizing outliers, the technique proposed in this article outperforms other state-of-the-art cluster kernels among all twelve implemented kernels. The comparison with the state-of-the-art string and mismatch kernels also show the superior performance scores provided by the proposed kernels. Similar performance improvement also is found over an existing large dataset. Therefore the proposed spectral clustering framework over combined local alignment kernels with modified symmetry based correction achieves superior performance for unsupervised remote homolog detection even in multi-domain and promiscuous domain proteins from Genolevures database families with better biological relevance. Source code available upon request. sarkar@labri.fr.

  5. Flexible And Secure Access To Computing Clusters

    Directory of Open Access Journals (Sweden)

    Jan Meizner

    2010-01-01

    Full Text Available The investigation presented in this paper was prompted by the need to provide a manageablesolution for secure access to computing clusters with a federated authentication framework.This requirement is especially important for scientists who need direct access to computingnodes in order to run their applications (e.g. chemical or medical simulations with proprietary,open-source or custom-developed software packages. Our existing software, whichenables non-Web clients to use Shibboleth-secured services, has been extended to providedirect SSH access to cluster nodes using the Linux Pluggable Authentication Modules mechanism.This allows Shibboleth users to run the required software on clusters. Validationand performance comparison with existing SSH authentication mechanisms confirm that thepresented tools satisfy the stated requirements.

  6. Comparative genomics of Cluster O mycobacteriophages.

    Directory of Open Access Journals (Sweden)

    Steven G Cresawn

    Full Text Available Mycobacteriophages--viruses of mycobacterial hosts--are genetically diverse but morphologically are all classified in the Caudovirales with double-stranded DNA and tails. We describe here a group of five closely related mycobacteriophages--Corndog, Catdawg, Dylan, Firecracker, and YungJamal--designated as Cluster O with long flexible tails but with unusual prolate capsids. Proteomic analysis of phage Corndog particles, Catdawg particles, and Corndog-infected cells confirms expression of half of the predicted gene products and indicates a non-canonical mechanism for translation of the Corndog tape measure protein. Bioinformatic analysis identifies 8-9 strongly predicted SigA promoters and all five Cluster O genomes contain more than 30 copies of a 17 bp repeat sequence with dyad symmetry located throughout the genomes. Comparison of the Cluster O phages provides insights into phage genome evolution including the processes of gene flux by horizontal genetic exchange.

  7. Document clustering methods, document cluster label disambiguation methods, document clustering apparatuses, and articles of manufacture

    Science.gov (United States)

    Sanfilippo, Antonio [Richland, WA; Calapristi, Augustin J [West Richland, WA; Crow, Vernon L [Richland, WA; Hetzler, Elizabeth G [Kennewick, WA; Turner, Alan E [Kennewick, WA

    2009-12-22

    Document clustering methods, document cluster label disambiguation methods, document clustering apparatuses, and articles of manufacture are described. In one aspect, a document clustering method includes providing a document set comprising a plurality of documents, providing a cluster comprising a subset of the documents of the document set, using a plurality of terms of the documents, providing a cluster label indicative of subject matter content of the documents of the cluster, wherein the cluster label comprises a plurality of word senses, and selecting one of the word senses of the cluster label.

  8. Studies in clustering theory

    Science.gov (United States)

    Stell, George

    In recent years the properties of percolation models have been studied intensively. The purpose of our project was to develop a general theory of percolation and clustering between particles of arbitrary size and shape, with arbitrary correlations between them. The goal of such a theory includes the treatment of continuum percolation as well as a novel treatment of lattice percolation. We made substantial progress toward this goal. The quantities basic to a description of clustering, the mean cluster size, mean number of clusters, etc., were developed. Concise formulas were given for the terms in such series, and proved, at least for sufficiently low densities, that the series are absolutely convergent. These series can now be used to construct Pade approximants that will allow one to probe the percolation transition. A scaled-particle theory of percolation was developed which gives analytic approximants for the mean number of clusters in a large class of two and three dimensional percolation models. Although this quantity is essential in many applications, e.g., explaining colligative properties, and interpreting low-angle light-scattering data, no systematic studies of it have been done before this work. Recently carried out detailed computer simulations show that the mean number of clusters is given to high accuracy by several of there approximations. Extensions of this work will allow calculation of the complete cluster size distribution.

  9. Structure and Mobility of Metal Clusters in MOFs: Au, Pd, and AuPd Clusters in MOF-74

    DEFF Research Database (Denmark)

    Vilhelmsen, Lasse; Walton, Krista S.; Sholl, David S.

    2012-01-01

    Understanding the adsorption and mobility of metal–organic framework (MOF)-supported metal nanoclusters is critical to the development of these catalytic materials. We present the first theoretical investigation of Au-, Pd-, and AuPd-supported clusters in a MOF, namely MOF-74. We combine density...... functional theory (DFT) calculations with a genetic algorithm (GA) to reliably predict the structure of the adsorbed clusters. This approach allows comparison of hundreds of adsorbed configurations for each cluster. From the investigation of Au8, Pd8, and Au4Pd4 we find that the organic part of the MOF...... is just as important for nanocluster adsorption as open Zn or Mg metal sites. Using the large number of clusters generated by the GA, we developed a systematic method for predicting the mobility of adsorbed clusters. Through the investigation of diffusion paths a relationship between the cluster...

  10. Natural Offshore Oil Seepage and Related Tarball Accumulation on the California Coastline - Santa Barbara Channel and the Southern Santa Maria Basin: Source Identification and Inventory

    Science.gov (United States)

    Lorenson, T.D.; Hostettler, Frances D.; Rosenbauer, Robert J.; Peters, Kenneth E.; Dougherty, Jennifer A.; Kvenvolden, Keith A.; Gutmacher, Christina E.; Wong, Florence L.; Normark, William R.

    2009-01-01

    Oil spillage from natural sources is very common in the waters of southern California. Active oil extraction and shipping is occurring concurrently within the region and it is of great interest to resource managers to be able to distinguish between natural seepage and anthropogenic oil spillage. The major goal of this study was to establish the geologic setting, sources, and ultimate dispersal of natural oil seeps in the offshore southern Santa Maria Basin and Santa Barbara Basins. Our surveys focused on likely areas of hydrocarbon seepage that are known to occur between Point Arguello and Ventura, California. Our approach was to 1) document the locations and geochemically fingerprint natural seep oils or tar; 2) geochemically fingerprint coastal tar residues and potential tar sources in this region, both onshore and offshore; 3) establish chemical correlations between offshore active seeps and coastal residues thus linking seep sources to oil residues; 4) measure the rate of natural seepage of individual seeps and attempt to assess regional natural oil and gas seepage rates; and 5) interpret the petroleum system history for the natural seeps. To document the location of sub-sea oil seeps, we first looked into previous studies within and near our survey area. We measured the concentration of methane gas in the water column in areas of reported seepage and found numerous gas plumes and measured high concentrations of methane in the water column. The result of this work showed that the seeps were widely distributed between Point Conception east to the vicinity of Coal Oil Point, and that they by in large occur within the 3-mile limit of California State waters. Subsequent cruises used sidescan and high resolution seismic to map the seafloor, from just south of Point Arguello, east to near Gaviota, California. The results of the methane survey guided the exploration of the area west of Point Conception east to Gaviota using a combination of seismic instruments. The

  11. Evolution Properties of Clusters and AXAF Contributions to understanding Clusters

    Science.gov (United States)

    Jones, Christine

    1998-01-01

    Our ROSAT survey for distant clusters of galaxies contains the largest solid angle of all ROSAT pointed surveying and thus has sufficient area to test the previously reported cluster evolution. We find significant negative cluster evolution, i.e,, at high redshifts there are fewer luminous clusters than at present. We compare optical cluster properties for the most distant clusters in the ROSAT survey with those measured for nearby clusters. We also present AXAF capabilities and show how AXAF will significantly extend our understanding of cluster properties and their cosmological evolution.

  12. Major Barbara Stimson: A Historical Perspective on the American Board of Surgery Through the Accomplishments of the First Woman to Achieve Board Certification.

    Science.gov (United States)

    Haisley, Kelly R; Drexel, Sabrina E; Watters, Jennifer M; Hunter, John G; Mullins, Richard J

    2017-12-21

    : Dr. Barbara Bartlett Stimson, AB, MD, MedScD, FACS (1898-1986) was a pioneering orthopedic surgeon from a prominent American family who, in 1940, became the first woman certified by the American Board of Surgery (ABS, certificate number 860). It would be another 7 years and approximately 2500 candidates before the next female surgeon would be certified. A member of the third class to admit women to Columbia Medical School and the second female surgical resident to complete training at Columbia-Presbyterian Medical Center, Dr. Stimson was a confident and exceptionally accomplished trailblazer for women in surgery. In this biographical sketch based upon documents from the ABS, and the archives of Vassar College and the College of Physicians and Surgeons at Columbia-Presbyterian Medical Center, Dr. Stimson's motivations, attitudes, and unique accomplishments emerge as testimony to the exceptional career of this driven, self-possessed woman. Stimson was undaunted by the sex-based conventions of her time, and achieved a notable career as a surgeon in the profession she loved; first honing her skills at a busy urban fracture service in New York, then serving with distinction in the Royal Army Medical Corps during World War II, and finally returning to the states to become a respected leader in her field. Her life story and unprecedented ABS certification affirm her conviction that proven skill and ability can be used as a means of overcoming unfounded biases, and helped pave the way for future generations of board certified female surgeons in the United States.

  13. Abrupt termination of Marine Isotope Stage 16 (Termination VII) at 631.5 ka in Santa Barbara Basin, Californi

    Science.gov (United States)

    Dean, Walter E.; Kennett, James P.; Behl, Richard J.; Nicholson, Craig; Sorlien, Christopher C.

    2015-01-01

    The Marine Isotope Stage 16–15 boundary (Termination VII) is the first deglacial warming step of the late Quaternary following the mid-Pleistocene transition (MPT), when 41 kyr climatic cycles shifted to strong 100 kyr cycles. The detailed structure of this important climatic event has remained unknown until now. Core MV0508-19JPC from Santa Barbara Basin, California, contains a decadal-scale climatic and geochemical sediment record of 4000 years duration that includes the early part of this deglacial episode. This record reveals that the climatic shift during the early deglacial occurred rapidly (<700 years), in a progression of three abrupt warming steps. The onset of Marine Isotope Stage (MIS) 15 was remarkably abrupt with 4–5°C sea surface warming in ~50 years. The deglacial sequence contains the well-dated Lava Creek tephra (631.3 ± 4 ka) from Yellowstone Caldera used to date the onset of Termination VII at 631.5 ka. The late MIS 16 and early MIS 15 interval exhibits multiple decadal-scale negative excursions in δ13C of planktic foraminifera, likely the result of repeated discharges of methane from methane hydrates associated with both ocean warming and low sea level. A warm interstadial that interrupts late MIS 16 is marked by elevated concentrations of redox-sensitive elements indicating sulfidic, oxygen-deficient bottom and pore-waters, and elevated concentrations of total organic carbon and Cd, reflecting increased surface productivity. Unlike younger sediments on the California margin, these indicators of increased productivity and low dissolved oxygen do not consistently correspond with each other or with preserved laminations, possibly reflecting instability of a still evolving ocean-atmosphere system following the MPT.

  14. A History of Warming Sea Surface Temperature and Ocean Acidification Recorded by Planktonic Foraminifera Geochemistry from the Santa Barbara Basin, California

    Science.gov (United States)

    Osborne, E.; Thunell, R.; Bizimis, M.; Buckley, W. P., Jr.; benitez-Nelson, C. R.; Chartier, C. J.

    2015-12-01

    The geochemistry of foraminiferal shells has been widely used to reconstruct past conditions of the ocean and climate. Since the onset of the Industrial Revolution, anthropogenically produced CO2 has resulted in an increase in global temperatures and a decline in the mean pH of the world's oceans. The California Current System is a particularly susceptible region to ocean acidification due to natural upwelling processes that also cause a reduction in seawater pH. The trace element concentration of magnesium and boron in planktonic foraminiferal shells are used here as proxies for temperature and carbonate ion concentration ([CO32-]), respectively. Newly developed calibrations relating Mg/Ca ratios to temperature (R2 0.91) and B/Ca ratios to [CO32-] (R2 0.84) for the surface-mixed layer species Globogerina bulloides were generated using material collected in the Santa Barbara Basin sediment trap time-series. Using these empirical relationships, temperature and [CO32-] are reconstructed using a 0.5 meter long multi-core collected within the basin. 210Pb activities were used to determine a sedimentation rate for the core to estimate ages for core samples (sedimentation rate: 0.341 cm/yr). A spike in 137Cs activity is used as a tie-point to the year 1965 coinciding with the peak of nuclear bomb testing. Our down-core record extends through the mid-19th century to create a history of rising sea surface temperatures and declining [CO32-] as a result of anthropogenic CO2 emissions.

  15. X-ray Spectra of Distant Clusters

    Science.gov (United States)

    Ellingson, E.

    1998-01-01

    The masses of galaxy clusters are dominated by dark matter, and a robust determination of their temperatures and masses has the potential of indicating how much dark matter exists on large scales in the universe, and the cosmological parameter Omega. X-ray observations of galaxy clusters provide a direct measure of both the gas mass in the intra-cluster medium, and also the total gravitating mass of the cluster. We used new and archival ASCA and ROSAT observations to measure these quantities for a sample of intermediate redshift clusters which have also been subject to intensive dynamical studies, in order to compare the mass estimates from different methods. We used data from 12 of the CNOC cluster sample at 0.18 less than z less than 0.55 for this study. A direct comparison of dynamical mass estimates from Carlberg, Yee & Ellingson (1997) yielded surprisingly good results. The X-ray/dynamical mass ratios have a mean of 0.96+/- 0.10, indicating that for this sample, both methods are probably yielding very robust mass estimates. Comparison with mass estimates from gravitational lensing studies from the literature showed a small systematic with weak lensing estimates, and large discrepancies with strong lensing estimates. This latter is not surprising, given that these measurements are made close to the central core, where optical and Xray estimates are less certain, and where substructure and the effects of individual galaxies will be more pronounced. These results are presented in Lewis, Ellingson, Morris \\& Carlberg, 1998, submitted to the Astrophysical Journal.

  16. Spanning Tree Based Attribute Clustering

    DEFF Research Database (Denmark)

    Zeng, Yifeng; Jorge, Cordero Hernandez

    2009-01-01

    inconsistent edges from a maximum spanning tree by starting appropriate initial modes, therefore generating stable clusters. It discovers sound clusters through simple graph operations and achieves significant computational savings. We compare the Star Discovery algorithm against earlier attribute clustering...

  17. Tune Your Brown Clustering, Please

    DEFF Research Database (Denmark)

    Derczynski, Leon; Chester, Sean; Bøgh, Kenneth Sejdenfaden

    2015-01-01

    Brown clustering, an unsupervised hierarchical clustering technique based on ngram mutual information, has proven useful in many NLP applications. However, most uses of Brown clustering employ the same default configuration; the appropriateness of this configuration has gone predominantly...

  18. Extending Beowulf Clusters

    Science.gov (United States)

    Steinwand, Daniel R.; Maddox, Brian; Beckmann, Tim; Hamer, George

    2003-01-01

    Beowulf clusters can provide a cost-effective way to compute numerical models and process large amounts of remote sensing image data. Usually a Beowulf cluster is designed to accomplish a specific set of processing goals, and processing is very efficient when the problem remains inside the constraints of the original design. There are cases, however, when one might wish to compute a problem that is beyond the capacity of the local Beowulf system. In these cases, spreading the problem to multiple clusters or to other machines on the network may provide a cost-effective solution.

  19. Distant galactic open clusters

    International Nuclear Information System (INIS)

    Christian, C.A.

    1980-01-01

    The motivation for studying distant open clusters primarily arose out of a desire to gain some understanding of star formation processes in the general context of galactic structure. Of specific interest are faint open clusters near the galactic anticenter which are part of a larger survey of objects which may be located in the 'periphery' of the Galaxy. A sample of results from broad-band photometric studies for clusters near lsup(II)=180 0 , bsup(II)=0 0 is presented. (Auth.)

  20. Introduction to cluster dynamics

    CERN Document Server

    Reinhard, Paul-Gerhard

    2008-01-01

    Clusters as mesoscopic particles represent an intermediate state of matter between single atoms and solid material. The tendency to miniaturise technical objects requires knowledge about systems which contain a ""small"" number of atoms or molecules only. This is all the more true for dynamical aspects, particularly in relation to the qick development of laser technology and femtosecond spectroscopy. Here, for the first time is a highly qualitative introduction to cluster physics. With its emphasis on cluster dynamics, this will be vital to everyone involved in this interdisciplinary subje

  1. Raspberry Pi super cluster

    CERN Document Server

    Dennis, Andrew K

    2013-01-01

    This book follows a step-by-step, tutorial-based approach which will teach you how to develop your own super cluster using Raspberry Pi computers quickly and efficiently.Raspberry Pi Super Cluster is an introductory guide for those interested in experimenting with parallel computing at home. Aimed at Raspberry Pi enthusiasts, this book is a primer for getting your first cluster up and running.Basic knowledge of C or Java would be helpful but no prior knowledge of parallel computing is necessary.

  2. Contextualizing the Cluster

    DEFF Research Database (Denmark)

    Giacomin, Valeria

    This dissertation examines the case of the palm oil cluster in Malaysia and Indonesia, today one of the largest agricultural clusters in the world. My analysis focuses on the evolution of the cluster from the 1880s to the 1970s in order to understand how it helped these two countries to integrate...... into the global economy in both colonial and post-colonial times. The study is based on empirical material drawn from five UK archives and background research using secondary sources, interviews, and archive visits to Malaysia and Singapore. The dissertation comprises three articles, each discussing a major under...

  3. Partially supervised speaker clustering.

    Science.gov (United States)

    Tang, Hao; Chu, Stephen Mingyu; Hasegawa-Johnson, Mark; Huang, Thomas S

    2012-05-01

    Content-based multimedia indexing, retrieval, and processing as well as multimedia databases demand the structuring of the media content (image, audio, video, text, etc.), one significant goal being to associate the identity of the content to the individual segments of the signals. In this paper, we specifically address the problem of speaker clustering, the task of assigning every speech utterance in an audio stream to its speaker. We offer a complete treatment to the idea of partially supervised speaker clustering, which refers to the use of our prior knowledge of speakers in general to assist the unsupervised speaker clustering process. By means of an independent training data set, we encode the prior knowledge at the various stages of the speaker clustering pipeline via 1) learning a speaker-discriminative acoustic feature transformation, 2) learning a universal speaker prior model, and 3) learning a discriminative speaker subspace, or equivalently, a speaker-discriminative distance metric. We study the directional scattering property of the Gaussian mixture model (GMM) mean supervector representation of utterances in the high-dimensional space, and advocate exploiting this property by using the cosine distance metric instead of the euclidean distance metric for speaker clustering in the GMM mean supervector space. We propose to perform discriminant analysis based on the cosine distance metric, which leads to a novel distance metric learning algorithm—linear spherical discriminant analysis (LSDA). We show that the proposed LSDA formulation can be systematically solved within the elegant graph embedding general dimensionality reduction framework. Our speaker clustering experiments on the GALE database clearly indicate that 1) our speaker clustering methods based on the GMM mean supervector representation and vector-based distance metrics outperform traditional speaker clustering methods based on the “bag of acoustic features” representation and statistical

  4. Two-Way Regularized Fuzzy Clustering of Multiple Correspondence Analysis.

    Science.gov (United States)

    Kim, Sunmee; Choi, Ji Yeh; Hwang, Heungsun

    2017-01-01

    Multiple correspondence analysis (MCA) is a useful tool for investigating the interrelationships among dummy-coded categorical variables. MCA has been combined with clustering methods to examine whether there exist heterogeneous subclusters of a population, which exhibit cluster-level heterogeneity. These combined approaches aim to classify either observations only (one-way clustering of MCA) or both observations and variable categories (two-way clustering of MCA). The latter approach is favored because its solutions are easier to interpret by providing explicitly which subgroup of observations is associated with which subset of variable categories. Nonetheless, the two-way approach has been built on hard classification that assumes observations and/or variable categories to belong to only one cluster. To relax this assumption, we propose two-way fuzzy clustering of MCA. Specifically, we combine MCA with fuzzy k-means simultaneously to classify a subgroup of observations and a subset of variable categories into a common cluster, while allowing both observations and variable categories to belong partially to multiple clusters. Importantly, we adopt regularized fuzzy k-means, thereby enabling us to decide the degree of fuzziness in cluster memberships automatically. We evaluate the performance of the proposed approach through the analysis of simulated and real data, in comparison with existing two-way clustering approaches.

  5. Quantification of the clustering properties of nuclear states

    International Nuclear Information System (INIS)

    Beck, R.; Dickmann, F.

    1985-05-01

    The amount of particular type of clustering in a nuclear state is defined in this paper as the norm square of the projection of the wave function onto the particular cluster model subspace. It is pointed out that, although the clusters can not be localized in space by measurement, the amount of clustering characterizes the cluster formation in close analogy with a quantum mechanical probability. The cluster model component of the wave function is proved to have a variational property. This facilitates the computation of the amount of clustering. The model dependence of the amounts of various clusterings and their relationship to the corresponding spectroscopic factors are studied via numerical examples for two models of sup(6)Li. It is concluded that, in a relative sense, the spectroscopic factor, which is more directly related to experiment, is also characteristic of the clustering contents of different states of the same nucleus, but it can not be used for comparisons between different nuclei or clusterings. (author)

  6. COCOA code for creating mock observations of star cluster models

    Science.gov (United States)

    Askar, Abbas; Giersz, Mirek; Pych, Wojciech; Dalessandro, Emanuele

    2018-04-01

    We introduce and present results from the COCOA (Cluster simulatiOn Comparison with ObservAtions) code that has been developed to create idealized mock photometric observations using results from numerical simulations of star cluster evolution. COCOA is able to present the output of realistic numerical simulations of star clusters carried out using Monte Carlo or N-body codes in a way that is useful for direct comparison with photometric observations. In this paper, we describe the COCOA code and demonstrate its different applications by utilizing globular cluster (GC) models simulated with the MOCCA (MOnte Carlo Cluster simulAtor) code. COCOA is used to synthetically observe these different GC models with optical telescopes, perform point spread function photometry, and subsequently produce observed colour-magnitude diagrams. We also use COCOA to compare the results from synthetic observations of a cluster model that has the same age and metallicity as the Galactic GC NGC 2808 with observations of the same cluster carried out with a 2.2 m optical telescope. We find that COCOA can effectively simulate realistic observations and recover photometric data. COCOA has numerous scientific applications that maybe be helpful for both theoreticians and observers that work on star clusters. Plans for further improving and developing the code are also discussed in this paper.

  7. How Clusters Work

    Science.gov (United States)

    Technology innovation clusters are geographic concentrations of interconnected companies, universities, and other organizations with a focus on environmental technology. They play a key role in addressing the nation’s pressing environmental problems.

  8. Clustering of Emerging Flux

    Science.gov (United States)

    Ruzmaikin, A.

    1997-01-01

    Observations show that newly emerging flux tends to appear on the Solar surface at sites where there is flux already. This results in clustering of solar activity. Standard dynamo theories do not predict this effect.

  9. Evolution of clustered storage

    CERN Multimedia

    CERN. Geneva; Van de Vyvre, Pierre

    2007-01-01

    The session actually featured two presentations: * Evolution of clustered storage by Lance Hukill, Quantum Corporation * ALICE DAQ - Usage of a Cluster-File System: Quantum StorNext by Pierre Vande Vyvre, CERN-PH the second one prepared at short notice by Pierre (thanks!) to present how the Quantum technologies are being used in the ALICE experiment. The abstract to Mr Hukill's follows. Clustered Storage is a technology that is driven by business and mission applications. The evolution of Clustered Storage solutions starts first at the alignment between End-users needs and Industry trends: * Push-and-Pull between managing for today versus planning for tomorrow * Breaking down the real business problems to the core applications * Commoditization of clients, servers, and target devices * Interchangeability, Interoperability, Remote Access, Centralized control * Oh, and yes, there is a budget and the "real world" to deal with This presentation will talk through these needs and trends, and then ask the question, ...

  10. Transition Matrix Cluster Algorithms

    OpenAIRE

    Yevick, David; Lee, Yong Hwan

    2018-01-01

    We demonstrate that a series of simple procedures for increasing the efficiency of transition matrix calculations can be realized by integrating the standard single-spin reversal transition matrix method with global cluster inversion techniques.

  11. Remarks on stellar clusters

    International Nuclear Information System (INIS)

    Teller, E.

    1985-01-01

    In the following, a few simple remarks on the evolution and properties of stellar clusters will be collected. In particular, globular clusters will be considered. Though details of such clusters are often not known, a few questions can be clarified with the help of primitive arguments. These are:- why are spherical clusters spherical, why do they have high densities, why do they consist of approximately a million stars, how may a black hole of great mass form within them, may they be the origin of gamma-ray bursts, may their invisible remnants account for the missing mass of our galaxy. The available data do not warrant a detailed evaluation. However, it is remarkable that exceedingly simple models can shed some light on the questions enumerated above. (author)

  12. Clustering on Membranes

    DEFF Research Database (Denmark)

    Johannes, Ludger; Pezeshkian, Weria; Ipsen, John H

    2018-01-01

    Clustering of extracellular ligands and proteins on the plasma membrane is required to perform specific cellular functions, such as signaling and endocytosis. Attractive forces that originate in perturbations of the membrane's physical properties contribute to this clustering, in addition to direct...... protein-protein interactions. However, these membrane-mediated forces have not all been equally considered, despite their importance. In this review, we describe how line tension, lipid depletion, and membrane curvature contribute to membrane-mediated clustering. Additional attractive forces that arise...... from protein-induced perturbation of a membrane's fluctuations are also described. This review aims to provide a survey of the current understanding of membrane-mediated clustering and how this supports precise biological functions....

  13. Applications of Clustering

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Applications of Clustering. Biology – medical imaging, bioinformatics, ecology, phylogenies problems etc. Market research. Data Mining. Social Networks. Any problem measuring similarity/correlation. (dimensions represent different parameters)

  14. Air void clustering.

    Science.gov (United States)

    2015-06-01

    Air void clustering around coarse aggregate in concrete has been identified as a potential source of : low strengths in concrete mixes by several Departments of Transportation around the country. Research was : carried out to (1) develop a quantitati...

  15. Cauchy cluster process

    DEFF Research Database (Denmark)

    Ghorbani, Mohammad

    2013-01-01

    In this paper we introduce an instance of the well-know Neyman–Scott cluster process model with clusters having a long tail behaviour. In our model the offspring points are distributed around the parent points according to a circular Cauchy distribution. Using a modified Cramér-von Misses test...... statistic and the simulated pointwise envelopes it is shown that this model fits better than the Thomas process to the frequently analyzed long-leaf pine data-set....

  16. Structure of Silicon Clusters

    OpenAIRE

    Pan, Jun; Bahel, Atul; Ramakrishna, Mushti V.

    1995-01-01

    We determined the structures of silicon clusters in the 11-14 atom size range using the tight-binding molecular dynamics method. These calculations reveal that \\Si{11} is an icosahedron with one missing cap, \\Si{12} is a complete icosahedron, \\Si{13} is a surface capped icosahedron, and \\Si{14} is a 4-4-4 layer structure with two caps. The characteristic feature of these clusters is that they are all surface.

  17. Robust continuous clustering.

    Science.gov (United States)

    Shah, Sohil Atul; Koltun, Vladlen

    2017-09-12

    Clustering is a fundamental procedure in the analysis of scientific data. It is used ubiquitously across the sciences. Despite decades of research, existing clustering algorithms have limited effectiveness in high dimensions and often require tuning parameters for different domains and datasets. We present a clustering algorithm that achieves high accuracy across multiple domains and scales efficiently to high dimensions and large datasets. The presented algorithm optimizes a smooth continuous objective, which is based on robust statistics and allows heavily mixed clusters to be untangled. The continuous nature of the objective also allows clustering to be integrated as a module in end-to-end feature learning pipelines. We demonstrate this by extending the algorithm to perform joint clustering and dimensionality reduction by efficiently optimizing a continuous global objective. The presented approach is evaluated on large datasets of faces, hand-written digits, objects, newswire articles, sensor readings from the Space Shuttle, and protein expression levels. Our method achieves high accuracy across all datasets, outperforming the best prior algorithm by a factor of 3 in average rank.

  18. Cluster fusion algorithm: application to Lennard-Jones clusters

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter

    2006-01-01

    We present a new general theoretical framework for modelling the cluster structure and apply it to description of the Lennard-Jones clusters. Starting from the initial tetrahedral cluster configuration, adding new atoms to the system and absorbing its energy at each step, we find cluster growing ...

  19. Determination of atomic cluster structure with cluster fusion algorithm

    DEFF Research Database (Denmark)

    Obolensky, Oleg I.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2005-01-01

    We report an efficient scheme of global optimization, called cluster fusion algorithm, which has proved its reliability and high efficiency in determination of the structure of various atomic clusters.......We report an efficient scheme of global optimization, called cluster fusion algorithm, which has proved its reliability and high efficiency in determination of the structure of various atomic clusters....

  20. Near infrared photometry of globular clusters

    International Nuclear Information System (INIS)

    Evans, T.L.; Menzies, J.W.

    1977-01-01

    Photographic photometry on the V, Isub(K) system has been obtained for giant stars in the metal-rich globular clusters NGC 5927, 6171, 6352, 6356, 6388, 6522, 6528, 6712 and 6723. Colour-magnitude diagrams are presented. These data, with earlier observations of NGC 104 (47 Tuc), yield new parameters to describe the giant branch. These are the colour of the red variables, represented by their mean colour (V - Isub(K)) 0 or by the colour (V - Isub(K))sub(BO) of the bluest red variable on the giant branch of a cluster, and ΔV' which is the magnitude difference between the horizontal branch and the highest point on the giant branch. The latter is independent of reddening, since the giant branch of the most metal-rich clusters passes through a maximum in the V, V - Isub(K) plane. These parameters are correlated with the metal content, deduced from integrated photometry: the red variables are redder and the giant branch fainter the higher the metal content. Comparison with theoretical evolutionary tracks suggests that the range in metal content of these clusters is at most a factor of 10, the most metal-rich clusters possibly approaching the solar value. The cluster giant branches and those of open clusters, groups and field stars of the old disk population are compared. The assumption that all the globular clusters have an absolute magnitude on the horizontal branch of Msub(v) = + 0.9, as found recently for 47 Tuc, gives good agreement between the magnitudes of giant stars in the most metal rich of the globular clusters and those of field stars deduced from statistical parallaxes and moving group parallaxes. The values of the parameters ΔV' and (V - Isub(k))sub(BO) also approach those in the moving groups. The globular clusters have a longer horizontal branch, however, and the subgiants are bluer even when the values of ) 7Fe/H{ appear to be the same. (author). )

  1. Enhanced peptide quantification using spectral count clustering and cluster abundance

    Directory of Open Access Journals (Sweden)

    Lee Seungmook

    2011-10-01

    Full Text Available Abstract Background Quantification of protein expression by means of mass spectrometry (MS has been introduced in various proteomics studies. In particular, two label-free quantification methods, such as spectral counting and spectra feature analysis have been extensively investigated in a wide variety of proteomic studies. The cornerstone of both methods is peptide identification based on a proteomic database search and subsequent estimation of peptide retention time. However, they often suffer from restrictive database search and inaccurate estimation of the liquid chromatography (LC retention time. Furthermore, conventional peptide identification methods based on the spectral library search algorithms such as SEQUEST or SpectraST have been found to provide neither the best match nor high-scored matches. Lastly, these methods are limited in the sense that target peptides cannot be identified unless they have been previously generated and stored into the database or spectral libraries. To overcome these limitations, we propose a novel method, namely Quantification method based on Finding the Identical Spectral set for a Homogenous peptide (Q-FISH to estimate the peptide's abundance from its tandem mass spectrometry (MS/MS spectra through the direct comparison of experimental spectra. Intuitively, our Q-FISH method compares all possible pairs of experimental spectra in order to identify both known and novel proteins, significantly enhancing identification accuracy by grouping replicated spectra from the same peptide targets. Results We applied Q-FISH to Nano-LC-MS/MS data obtained from human hepatocellular carcinoma (HCC and normal liver tissue samples to identify differentially expressed peptides between the normal and disease samples. For a total of 44,318 spectra obtained through MS/MS analysis, Q-FISH yielded 14,747 clusters. Among these, 5,777 clusters were identified only in the HCC sample, 6,648 clusters only in the normal tissue sample

  2. Cluster fusion algorithm: application to Lennard-Jones clusters

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter

    2008-01-01

    We present a new general theoretical framework for modelling the cluster structure and apply it to description of the Lennard-Jones clusters. Starting from the initial tetrahedral cluster configuration, adding new atoms to the system and absorbing its energy at each step, we find cluster growing...... paths up to the cluster size of 150 atoms. We demonstrate that in this way all known global minima structures of the Lennard-Jones clusters can be found. Our method provides an efficient tool for the calculation and analysis of atomic cluster structure. With its use we justify the magic number sequence...... for the clusters of noble gas atoms and compare it with experimental observations. We report the striking correspondence of the peaks in the dependence of the second derivative of the binding energy per atom on cluster size calculated for the chain of the Lennard-Jones clusters based on the icosahedral symmetry...

  3. Isospin breaking from diquark clustering

    Science.gov (United States)

    Gibbs, W. R.; Dedonder, Jean-Pierre

    2017-09-01

    Background: Although SU(2) isospin symmetry is generally assumed in the basic theory of the strong interaction, a number of significant violations have been observed in scattering and bound states of nucleons. Many of these violations can be attributed to the electromagnetic interaction but the question of how much of the violation is due to it remains open. Purpose: To establish the connection between diquark clustering in the two-nucleon system and isospin breaking from the Coulomb interaction between the members of diquark pairs. Method: A schematic model based on clustering of quarks in the interior of the confinement region of the two-nucleon system is introduced and evaluated. In this model the Coulomb interaction is the source of all isospin breaking. It draws on a picture of the quark density based on the diquark-quark model of hadron structure which has been investigated by a number of groups. Results: The model produces three isospin breaking potentials connecting the unbroken value of the low-energy scattering amplitude to those of the p p , n n , and n p singlet channels. A simple test of the potentials in the three-nucleon energy difference problem yields results in agreement with the known binding energy difference. Conclusion: The illustrative model suggests that the breaking seen in the low-energy nucleon-nucleon (NN) interaction may be understood in terms of the Coulomb force between members of diquark clusters. It allows the prediction of the charge symmetry breaking interaction and the n n scattering length from the well measured n p singlet scattering length. Values of the n n scattering length around -18 fm are favored. Since the model is based on the quark picture, it can be easily extended, in the SU(3) limit, to calculate isospin breaking in the strange sector in the corresponding channels. A natural consequence of isospin breaking from diquark clustering is that the breaking in the strange sector, as measured by the separation energy

  4. Relation chain based clustering analysis

    Science.gov (United States)

    Zhang, Cheng-ning; Zhao, Ming-yang; Luo, Hai-bo

    2011-08-01

    Clustering analysis is currently one of well-developed branches in data mining technology which is supposed to find the hidden structures in the multidimensional space called feature or pattern space. A datum in the space usually possesses a vector form and the elements in the vector represent several specifically selected features. These features are often of efficiency to the problem oriented. Generally, clustering analysis goes into two divisions: one is based on the agglomerative clustering method, and the other one is based on divisive clustering method. The former refers to a bottom-up process which regards each datum as a singleton cluster while the latter refers to a top-down process which regards entire data as a cluster. As the collected literatures, it is noted that the divisive clustering is currently overwhelming both in application and research. Although some famous divisive clustering methods are designed and well developed, clustering problems are still far from being solved. The k - means algorithm is the original divisive clustering method which initially assigns some important index values, such as the clustering number and the initial clustering prototype positions, and that could not be reasonable in some certain occasions. More than the initial problem, the k - means algorithm may also falls into local optimum, clusters in a rigid way and is not available for non-Gaussian distribution. One can see that seeking for a good or natural clustering result, in fact, originates from the one's understanding of the concept of clustering. Thus, the confusion or misunderstanding of the definition of clustering always derives some unsatisfied clustering results. One should consider the definition deeply and seriously. This paper demonstrates the nature of clustering, gives the way of understanding clustering, discusses the methodology of designing a clustering algorithm, and proposes a new clustering method based on relation chains among 2D patterns. In

  5. Exploring cosmic origins with CORE: Cluster science

    Science.gov (United States)

    Melin, J.-B.; Bonaldi, A.; Remazeilles, M.; Hagstotz, S.; Diego, J. M.; Hernández-Monteagudo, C.; Génova-Santos, R. T.; Luzzi, G.; Martins, C. J. A. P.; Grandis, S.; Mohr, J. J.; Bartlett, J. G.; Delabrouille, J.; Ferraro, S.; Tramonte, D.; Rubiño-Martín, J. A.; Macìas-Pérez, J. F.; Achúcarro, A.; Ade, P.; Allison, R.; Ashdown, M.; Ballardini, M.; Banday, A. J.; Banerji, R.; Bartolo, N.; Basak, S.; Basu, K.; Battye, R. A.; Baumann, D.; Bersanelli, M.; Bonato, M.; Borrill, J.; Bouchet, F.; Boulanger, F.; Brinckmann, T.; Bucher, M.; Burigana, C.; Buzzelli, A.; Cai, Z.-Y.; Calvo, M.; Carvalho, C. S.; Castellano, M. G.; Challinor, A.; Chluba, J.; Clesse, S.; Colafrancesco, S.; Colantoni, I.; Coppolecchia, A.; Crook, M.; D'Alessandro, G.; de Bernardis, P.; de Gasperis, G.; De Petris, M.; De Zotti, G.; Di Valentino, E.; Errard, J.; Feeney, S. M.; Fernández-Cobos, R.; Finelli, F.; Forastieri, F.; Galli, S.; Gerbino, M.; González-Nuevo, J.; Greenslade, J.; Hanany, S.; Handley, W.; Hervias-Caimapo, C.; Hills, M.; Hivon, E.; Kiiveri, K.; Kisner, T.; Kitching, T.; Kunz, M.; Kurki-Suonio, H.; Lamagna, L.; Lasenby, A.; Lattanzi, M.; Le Brun, A. M. C.; Lesgourgues, J.; Lewis, A.; Liguori, M.; Lindholm, V.; Lopez-Caniego, M.; Maffei, B.; Martinez-Gonzalez, E.; Masi, S.; Mazzotta, P.; McCarthy, D.; Melchiorri, A.; Molinari, D.; Monfardini, A.; Natoli, P.; Negrello, M.; Notari, A.; Paiella, A.; Paoletti, D.; Patanchon, G.; Piat, M.; Pisano, G.; Polastri, L.; Polenta, G.; Pollo, A.; Poulin, V.; Quartin, M.; Roman, M.; Salvati, L.; Tartari, A.; Tomasi, M.; Trappe, N.; Triqueneaux, S.; Trombetti, T.; Tucker, C.; Väliviita, J.; van de Weygaert, R.; Van Tent, B.; Vennin, V.; Vielva, P.; Vittorio, N.; Weller, J.; Young, K.; Zannoni, M.

    2018-04-01

    We examine the cosmological constraints that can be achieved with a galaxy cluster survey with the future CORE space mission. Using realistic simulations of the millimeter sky, produced with the latest version of the Planck Sky Model, we characterize the CORE cluster catalogues as a function of the main mission performance parameters. We pay particular attention to telescope size, key to improved angular resolution, and discuss the comparison and the complementarity of CORE with ambitious future ground-based CMB experiments that could be deployed in the next decade. A possible CORE mission concept with a 150 cm diameter primary mirror can detect of the order of 50,000 clusters through the thermal Sunyaev-Zeldovich effect (SZE). The total yield increases (decreases) by 25% when increasing (decreasing) the mirror diameter by 30 cm. The 150 cm telescope configuration will detect the most massive clusters (>1014 Msolar) at redshift z>1.5 over the whole sky, although the exact number above this redshift is tied to the uncertain evolution of the cluster SZE flux-mass relation; assuming self-similar evolution, CORE will detect 0~ 50 clusters at redshift z>1.5. This changes to 800 (200) when increasing (decreasing) the mirror size by 30 cm. CORE will be able to measure individual cluster halo masses through lensing of the cosmic microwave background anisotropies with a 1-σ sensitivity of 4×1014 Msolar, for a 120 cm aperture telescope, and 1014 Msolar for a 180 cm one. From the ground, we estimate that, for example, a survey with about 150,000 detectors at the focus of 350 cm telescopes observing 65% of the sky would be shallower than CORE and detect about 11,000 clusters, while a survey with the same number of detectors observing 25% of sky with a 10 m telescope is expected to be deeper and to detect about 70,000 clusters. When combined with the latter, CORE would reach a limiting mass of M500 ~ 2‑3 × 1013 Msolar and detect 220,000 clusters (5 sigma detection limit

  6. Subspace K-means clustering

    NARCIS (Netherlands)

    Timmerman, Marieke E.; Ceulemans, Eva; De Roover, Kim; Van Leeuwen, Karla

    2013-01-01

    To achieve an insightful clustering of multivariate data, we propose subspace K-means. Its central idea is to model the centroids and cluster residuals in reduced spaces, which allows for dealing with a wide range of cluster types and yields rich interpretations of the clusters. We review the

  7. FINDCLUS : Fuzzy INdividual Differences CLUStering

    NARCIS (Netherlands)

    Giordani, Paolo; Kiers, Henk A. L.

    ADditive CLUStering (ADCLUS) is a tool for overlapping clustering of two-way proximity matrices (objects x objects). In Simple Additive Fuzzy Clustering (SAFC), a variant of ADCLUS is introduced providing a fuzzy partition of the objects, that is the objects belong to the clusters with the so-called

  8. Misty Mountain clustering: application to fast unsupervised flow cytometry gating

    Directory of Open Access Journals (Sweden)

    Sealfon Stuart C

    2010-10-01

    Full Text Available Abstract Background There are many important clustering questions in computational biology for which no satisfactory method exists. Automated clustering algorithms, when applied to large, multidimensional datasets, such as flow cytometry data, prove unsatisfactory in terms of speed, problems with local minima or cluster shape bias. Model-based approaches are restricted by the assumptions of the fitting functions. Furthermore, model based clustering requires serial clustering for all cluster numbers within a user defined interval. The final cluster number is then selected by various criteria. These supervised serial clustering methods are time consuming and frequently different criteria result in different optimal cluster numbers. Various unsupervised heuristic approaches that have been developed such as affinity propagation are too expensive to be applied to datasets on the order of 106 points that are often generated by high throughput experiments. Results To circumvent these limitations, we developed a new, unsupervised density contour clustering algorithm, called Misty Mountain, that is based on percolation theory and that efficiently analyzes large data sets. The approach can be envisioned as a progressive top-down removal of clouds covering a data histogram relief map to identify clusters by the appearance of statistically distinct peaks and ridges. This is a parallel clustering method that finds every cluster after analyzing only once the cross sections of the histogram. The overall run time for the composite steps of the algorithm increases linearly by the number of data points. The clustering of 106 data points in 2D data space takes place within about 15 seconds on a standard laptop PC. Comparison of the performance of this algorithm with other state of the art automated flow cytometry gating methods indicate that Misty Mountain provides substantial improvements in both run time and in the accuracy of cluster assignment. Conclusions

  9. Fuzzy and hard clustering analysis for thyroid disease.

    Science.gov (United States)

    Azar, Ahmad Taher; El-Said, Shaimaa Ahmed; Hassanien, Aboul Ella

    2013-07-01

    Thyroid hormones produced by the thyroid gland help regulation of the body's metabolism. A variety of methods have been proposed in the literature for thyroid disease classification. As far as we know, clustering techniques have not been used in thyroid diseases data set so far. This paper proposes a comparison between hard and fuzzy clustering algorithms for thyroid diseases data set in order to find the optimal number of clusters. Different scalar validity measures are used in comparing the performances of the proposed clustering systems. To demonstrate the performance of each algorithm, the feature values that represent thyroid disease are used as input for the system. Several runs are carried out and recorded with a different number of clusters being specified for each run (between 2 and 11), so as to establish the optimum number of clusters. To find the optimal number of clusters, the so-called elbow criterion is applied. The experimental results revealed that for all algorithms, the elbow was located at c=3. The clustering results for all algorithms are then visualized by the Sammon mapping method to find a low-dimensional (normally 2D or 3D) representation of a set of points distributed in a high dimensional pattern space. At the end of this study, some recommendations are formulated to improve determining the actual number of clusters present in the data set. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  10. Cluster Implantation and Deposition Apparatus

    DEFF Research Database (Denmark)

    Hanif, Muhammad; Popok, Vladimir

    2015-01-01

    In the current report, a design and capabilities of a cluster implantation and deposition apparatus (CIDA) involving two different cluster sources are described. The clusters produced from gas precursors (Ar, N etc.) by PuCluS-2 can be used to study cluster ion implantation in order to develop...... contributions to the theory of cluster stopping in matter as well as for practical applications requiring ultra-shallow implantation and modification of surfaces on the nanoscale. Metal clusters from the magnetron cluster source are of interest for the production of optical sensors to detect specific biological...

  11. Cosmology and cluster formation

    International Nuclear Information System (INIS)

    Peebles, P.J.E.

    1990-01-01

    I discuss some issues that arise in the attempt to understand what rich clusters of galaxies might teach us about cosmology. First, the mean mass per galaxy in a cluster, if applied to all bright galaxies, yields a mean mass density ∼ 30 percent of the critical Einstein-de Sitter value. Is this because the mass per galaxy is biased low in clusters, or is there in a low density universe? Second, what is the sequence of creation? There are theories in which protoclusters form before galaxies, or after, or the two are more or less coeval. Third, can clusters have formed by gravitational instability out of Gaussian primeval density fluctuations? Or do the observations point to the non-Gaussian perturbations to be expected from cosmic strings, or explosions, or even some variants of inflation? These issues depend on a fourth: do we know the gross physical properties of clusters well enough to use them as constraints on cosmology? I argue that some are too well established to ignore. Their implications for the other issues are not so clear, but progress can be seen. (author)

  12. Projected coupled cluster theory.

    Science.gov (United States)

    Qiu, Yiheng; Henderson, Thomas M; Zhao, Jinmo; Scuseria, Gustavo E

    2017-08-14

    Coupled cluster theory is the method of choice for weakly correlated systems. But in the strongly correlated regime, it faces a symmetry dilemma, where it either completely fails to describe the system or has to artificially break certain symmetries. On the other hand, projected Hartree-Fock theory captures the essential physics of many kinds of strong correlations via symmetry breaking and restoration. In this work, we combine and try to retain the merits of these two methods by applying symmetry projection to broken symmetry coupled cluster wave functions. The non-orthogonal nature of states resulting from the application of symmetry projection operators furnishes particle-hole excitations to all orders, thus creating an obstacle for the exact evaluation of overlaps. Here we provide a solution via a disentanglement framework theory that can be approximated rigorously and systematically. Results of projected coupled cluster theory are presented for molecules and the Hubbard model, showing that spin projection significantly improves unrestricted coupled cluster theory while restoring good quantum numbers. The energy of projected coupled cluster theory reduces to the unprojected one in the thermodynamic limit, albeit at a much slower rate than projected Hartree-Fock.

  13. Rotating clusters in nuclei

    International Nuclear Information System (INIS)

    Pauling, L.; Robinson, A.B.

    1975-01-01

    Values of R, the radius of rotation of the rotating cluster, are calculated from the energy of the lowest 2 + level of even-even nuclei with the assumption that the cluster consists of p 2 or n 2 respectively, for N or P magic, and of a helion (α) for N or P differing from a magic number by +-2. The values as a function of A show a zigzag course, which is correlated with the polyspheron structure of the nuclei. If the mantle is not overcrowded the cluster glides over the surface of the mantle and the value of R increases by one spheron diameter, about 3.2 fm. At certain values of N a change in structure of the nucleus occurs, with increase in radius of the core by half a spheron diameter, permitting the cluster to drop back into the mantle, with decrease in R by half a spheron diameter. In the lanthanon region of permanent prolate deformation the rotating cluster is a polyhelion, containing the number of helions permitted by the difference between Z or N and the nearest magic number, and in the actinon region it contains all the nucleons beyond 208 Pb, with maximum p 10 n 16 . An explanation is given of the difference between these regions. (author)

  14. Globular Clusters - Guides to Galaxies

    CERN Document Server

    Richtler, Tom; Joint ESO-FONDAP Workshop on Globular Clusters

    2009-01-01

    The principal question of whether and how globular clusters can contribute to a better understanding of galaxy formation and evolution is perhaps the main driving force behind the overall endeavour of studying globular cluster systems. Naturally, this splits up into many individual problems. The objective of the Joint ESO-FONDAP Workshop on Globular Clusters - Guides to Galaxies was to bring together researchers, both observational and theoretical, to present and discuss the most recent results. Topics covered in these proceedings are: internal dynamics of globular clusters and interaction with host galaxies (tidal tails, evolution of cluster masses), accretion of globular clusters, detailed descriptions of nearby cluster systems, ultracompact dwarfs, formations of massive clusters in mergers and elsewhere, the ACS Virgo survey, galaxy formation and globular clusters, dynamics and kinematics of globular cluster systems and dark matter-related problems. With its wide coverage of the topic, this book constitute...

  15. Comparison of two modes of vitamin B12 supplementation on neuroconduction and cognitive function among older people living in Santiago, Chile: a cluster randomized controlled trial. a study protocol [ISRCTN 02694183

    Directory of Open Access Journals (Sweden)

    Brito Alex

    2011-09-01

    Full Text Available Abstract Background Older people have a high risk of vitamin B12 deficiency; this can lead to varying degrees of cognitive and neurological impairment. CBL deficiency may present as macrocytic anemia, subacute combined degeneration of the spinal cord, or as neuropathy, but is often asymptomatic in older people. Less is known about subclinical vitamin B12 deficiency and concurrent neuroconduction and cognitive impairment. A Programme of Complementary Feeding for the Older Population (PACAM in Chile delivers 2 complementary fortified foods that provide approximately 1.4 μg/day of vitamin B12 (2.4 μg/day elderly RDA. The aim of the present study is to assess whether supplementation with vitamin B12 will improve neuroconduction and cognitive function in older people who have biochemical evidence of vitamin B12 insufficiency in the absence of clinical deficiency. Methods We designed a cluster double-blind placebo-controlled trial involving community dwelling people aged 70-79 living in Santiago, Chile. We randomized 15 clusters (health centers involving 300 people (20 per cluster. Each cluster will be randomly assigned to one of three arms: a a 1 mg vitamin B12 pill taken daily and a routine PACAM food; b a placebo pill and the milk-PACAM food fortified to provide 1 mg of vitamin B12; c the routine PACAM food and a placebo pill. The study has been designed as an 18 month follow up period. The primary outcomes assessed at baseline, 4, 9 and 18 months will be: serum levels of vitamin B12, neuroconduction and cognitive function. Conclusions In view of the high prevalence of vitamin B12 deficiency in later life, the present study has potential public health interest because since it will measure the impact of the existing program of complementary feeding as compared to two options that provide higher vitamin B12 intakes that might potentially may contribute in preserving neurophysiologic and cognitive function and thus improve quality of life for older

  16. Nuclear Structure Calculations with Coupled Cluster Methods from Quantum Chemistry

    CERN Document Server

    Dean, D.J.; Hagen, G.; Hjorth-Jensen, M.; Kowalski, K.; Papenbrock, T.; Piecuch, P.; Wloch, M.

    2005-01-01

    We present several coupled-cluster calculations of ground and excited states of 4He and 16O employing methods from quantum chemistry. A comparison of coupled cluster results with the results of exact diagonalization of the hamiltonian in the same model space and other truncated shell-model calculations shows that the quantum chemistry inspired coupled cluster approximations provide an excellent description of ground and excited states of nuclei, with much less computational effort than traditional large-scale shell-model approaches. Unless truncations are made, for nuclei like 16O, full-fledged shell-model calculations with four or more major shells are not possible. However, these and even larger systems can be studied with the coupled cluster methods due to the polynomial rather than factorial scaling inherent in standard shell-model studies. This makes the coupled cluster approaches, developed in quantum chemistry, viable methods for describing weakly bound systems of interest for future nuclear facilities...

  17. Clustering Game Behavior Data

    DEFF Research Database (Denmark)

    Bauckhage, C.; Drachen, Anders; Sifa, Rafet

    2015-01-01

    Recent years have seen a deluge of behavioral data from players hitting the game industry. Reasons for this data surge are many and include the introduction of new business models, technical innovations, the popularity of online games, and the increasing persistence of games. Irrespective...... of the causes, the proliferation of behavioral data poses the problem of how to derive insights therefrom. Behavioral data sets can be large, time-dependent and high-dimensional. Clustering offers a way to explore such data and to discover patterns that can reduce the overall complexity of the data. Clustering...... scientists and present a review and tutorial focusing on the application of clustering techniques to mine behavioral game data. Several algorithms are reviewed and examples of their application shown. Key topics such as feature normalization are discussed and open problems in the context of game analytics...

  18. Spanish clitic clusters

    Directory of Open Access Journals (Sweden)

    María Cristina Cuervo

    2013-11-01

    Full Text Available This paper deals with a small set of data from clusters of three clitics in Spanish that questions the empirical adequacy and scope of previous analyses of clitic clusters in Romance. It is shown that the output of the Spurious se Rule is not identical to genuine se, at some level that is relevant for linearization of clitics within a cluster. A proposal is presented to capture the neglected data, and this is done in a way that illuminates the debate on the division of labour in clitic phenomena between phonology, morphology and syntax. Central questions in morphology, such as ordering of operations, syncretisms, linearization principles and consequences of lexical insertion are addressed and re-examined.

  19. Exotic cluster structures on

    CERN Document Server

    Gekhtman, M; Vainshtein, A

    2017-01-01

    This is the second paper in the series of papers dedicated to the study of natural cluster structures in the rings of regular functions on simple complex Lie groups and Poisson-Lie structures compatible with these cluster structures. According to our main conjecture, each class in the Belavin-Drinfeld classification of Poisson-Lie structures on \\mathcal{G} corresponds to a cluster structure in \\mathcal{O}(\\mathcal{G}). The authors have shown before that this conjecture holds for any \\mathcal{G} in the case of the standard Poisson-Lie structure and for all Belavin-Drinfeld classes in SL_n, n<5. In this paper the authors establish it for the Cremmer-Gervais Poisson-Lie structure on SL_n, which is the least similar to the standard one.

  20. The concept of cluster

    DEFF Research Database (Denmark)

    Laursen, Lea Louise Holst; Møller, Jørgen

    2013-01-01

    villages in order to secure their future. This paper will address the concept of cluster-villages as a possible approach to strengthen the conditions of contemporary Danish villages. Cluster-villages is a concept that gather a number of villages in a network-structure where the villages both work together...... important role to play in both the popular and the political debate and in relation to everyday living conditions. The debate about the future of rural Denmark is also very much a debate about the kind of welfare model we choose in self-governing, municipal Denmark. The centralised, specialised model based...... to forskellige positioner ser vi en ny mulighed for landsbyudvikling, som vi kalder Clustervillages. In order to investigate the potentials and possibilities of the cluster-village concept the paper will seek to unfold the concept strategically; looking into the benefits of such concept. Further, the paper seeks...

  1. Hierarchical clustering techniques for image database organization and summarization

    Science.gov (United States)

    Vellaikal, Asha; Kuo, C.-C. Jay

    1998-10-01

    This paper investigates clustering techniques as a method of organizing image databases to support popular visual management functions such as searching, browsing and navigation. Different types of hierarchical agglomerative clustering techniques are studied as a method of organizing features space as well as summarizing image groups by the selection of a few appropriate representatives. Retrieval performance using both single and multiple level hierarchies are experimented with and the algorithms show an interesting relationship between the top k correct retrievals and the number of comparisons required. Some arguments are given to support the use of such cluster-based techniques for managing distributed image databases.

  2. Topological modeling and classification of mammographic microcalcification clusters.

    Science.gov (United States)

    Chen, Zhili; Strange, Harry; Oliver, Arnau; Denton, Erika R E; Boggis, Caroline; Zwiggelaar, Reyer

    2015-04-01

    The presence of microcalcification clusters is a primary sign of breast cancer; however, it is difficult and time consuming for radiologists to classify microcalcifications as malignant or benign. In this paper, a novel method for the classification of microcalcification clusters in mammograms is proposed. The topology/connectivity of individual microcalcifications is analyzed within a cluster using multiscale morphology. This is distinct from existing approaches that tend to concentrate on the morphology of individual microcalcifications and/or global (statistical) cluster features. A set of microcalcification graphs are generated to represent the topological structure of microcalcification clusters at different scales. Subsequently, graph theoretical features are extracted, which constitute the topological feature space for modeling and classifying microcalcification clusters. k-nearest-neighbors-based classifiers are employed for classifying microcalcification clusters. The validity of the proposed method is evaluated using two well-known digitized datasets (MIAS and DDSM) and a full-field digital dataset. High classification accuracies (up to 96%) and good ROC results (area under the ROC curve up to 0.96) are achieved. A full comparison with related publications is provided, which includes a direct comparison. The results indicate that the proposed approach is able to outperform the current state-of-the-art methods. Significance: This study shows that topology modeling is an important tool for microcalcification analysis not only because of the improved classification accuracy but also because the topological measures can be linked to clinical understanding.

  3. Clustering via Kernel Decomposition

    DEFF Research Database (Denmark)

    Have, Anna Szynkowiak; Girolami, Mark A.; Larsen, Jan

    2006-01-01

    Methods for spectral clustering have been proposed recently which rely on the eigenvalue decomposition of an affinity matrix. In this work it is proposed that the affinity matrix is created based on the elements of a non-parametric density estimator. This matrix is then decomposed to obtain...... posterior probabilities of class membership using an appropriate form of nonnegative matrix factorization. The troublesome selection of hyperparameters such as kernel width and number of clusters can be obtained using standard cross-validation methods as is demonstrated on a number of diverse data sets....

  4. South Asian Cluster

    Directory of Open Access Journals (Sweden)

    Ionel Sergiu Pirju

    2014-12-01

    Full Text Available This article aims at presenting the South Asian cluster composed of India, Indonesia, Iran and Malaysia, the intercultural values that characterizes it, the supported leadership style and tracing the main macroeconomic considerations which characterizes them. The research is synchronic, analysing the contemporary situation of these countries without reference to their evolution in time, by using the positivist paradigm that explains the reality at one point. It will be analysed the overall cluster with the existing interactions between the countries that composes it, while the article being one of information will avoid building recommendation, or new theories.

  5. Chemical ionization of clusters formed from sulfuric acid and dimethylamine or diamines

    Science.gov (United States)

    Jen, Coty N.; Zhao, Jun; McMurry, Peter H.; Hanson, David R.

    2016-10-01

    Chemical ionization (CI) mass spectrometers are used to study atmospheric nucleation by detecting clusters produced by reactions of sulfuric acid and various basic gases. These instruments typically use nitrate to deprotonate and thus chemically ionize the clusters. In this study, we compare cluster concentrations measured using either nitrate or acetate. Clusters were formed in a flow reactor from vapors of sulfuric acid and dimethylamine, ethylene diamine, tetramethylethylene diamine, or butanediamine (also known as putrescine). These comparisons show that nitrate is unable to chemically ionize clusters with high base content. In addition, we vary the ion-molecule reaction time to probe ion processes which include proton-transfer, ion-molecule clustering, and decomposition of ions. Ion decomposition upon deprotonation by acetate/nitrate was observed. More studies are needed to quantify to what extent ion decomposition affects observed cluster content and concentrations, especially those chemically ionized with acetate since it deprotonates more types of clusters than nitrate.Model calculations of the neutral and ion cluster formation pathways are also presented to better identify the cluster types that are not efficiently deprotonated by nitrate. Comparison of model and measured clusters indicate that sulfuric acid dimers with two diamines and sulfuric acid trimers with two or more base molecules are not efficiently chemical ionized by nitrate. We conclude that acetate CI provides better information on cluster abundancies and their base content than nitrate CI.

  6. Effective implementation of hierarchical clustering

    Science.gov (United States)

    Verma, Mudita; Vijayarajan, V.; Sivashanmugam, G.; Bessie Amali, D. Geraldine

    2017-11-01

    Hierarchical clustering is generally used for cluster analysis in which we build up a hierarchy of clusters. In order to find that which cluster should be split a large amount of observations are being carried out. Here the data set of US based personalities has been considered for clustering. After implementation of hierarchical clustering on the data set we group it in three different clusters one is of politician, sports person and musicians. Training set is the main parameter which decides the category which has to be assigned to the observations that are being collected. The category of these observations must be known. Recognition comes from the formulation of classification. Supervised learning has the main instance in the form of classification. While on the other hand Clustering is an instance of unsupervised procedure. Clustering consists of grouping of data that have similar properties which are either their own or are inherited from some other sources.

  7. Clustering of resting state networks.

    Directory of Open Access Journals (Sweden)

    Megan H Lee

    Full Text Available The goal of the study was to demonstrate a hierarchical structure of resting state activity in the healthy brain using a data-driven clustering algorithm.The fuzzy-c-means clustering algorithm was applied to resting state fMRI data in cortical and subcortical gray matter from two groups acquired separately, one of 17 healthy individuals and the second of 21 healthy individuals. Different numbers of clusters and different starting conditions were used. A cluster dispersion measure determined the optimal numbers of clusters. An inner product metric provided a measure of similarity between different clusters. The two cluster result found the task-negative and task-positive systems. The cluster dispersion measure was minimized with seven and eleven clusters. Each of the clusters in the seven and eleven cluster result was associated with either the task-negative or task-positive system. Applying the algorithm to find seven clusters recovered previously described resting state networks, including the default mode network, frontoparietal control network, ventral and dorsal attention networks, somatomotor, visual, and language networks. The language and ventral attention networks had significant subcortical involvement. This parcellation was consistently found in a large majority of algorithm runs under different conditions and was robust to different methods of initialization.The clustering of resting state activity using different optimal numbers of clusters identified resting state networks comparable to previously obtained results. This work reinforces the observation that resting state networks are hierarchically organized.

  8. Clustering of resting state networks.

    Science.gov (United States)

    Lee, Megan H; Hacker, Carl D; Snyder, Abraham Z; Corbetta, Maurizio; Zhang, Dongyang; Leuthardt, Eric C; Shimony, Joshua S

    2012-01-01

    The goal of the study was to demonstrate a hierarchical structure of resting state activity in the healthy brain using a data-driven clustering algorithm. The fuzzy-c-means clustering algorithm was applied to resting state fMRI data in cortical and subcortical gray matter from two groups acquired separately, one of 17 healthy individuals and the second of 21 healthy individuals. Different numbers of clusters and different starting conditions were used. A cluster dispersion measure determined the optimal numbers of clusters. An inner product metric provided a measure of similarity between different clusters. The two cluster result found the task-negative and task-positive systems. The cluster dispersion measure was minimized with seven and eleven clusters. Each of the clusters in the seven and eleven cluster result was associated with either the task-negative or task-positive system. Applying the algorithm to find seven clusters recovered previously described resting state networks, including the default mode network, frontoparietal control network, ventral and dorsal attention networks, somatomotor, visual, and language networks. The language and ventral attention networks had significant subcortical involvement. This parcellation was consistently found in a large majority of algorithm runs under different conditions and was robust to different methods of initialization. The clustering of resting state activity using different optimal numbers of clusters identified resting state networks comparable to previously obtained results. This work reinforces the observation that resting state networks are hierarchically organized.

  9. Clustering: a neural network approach.

    Science.gov (United States)

    Du, K-L

    2010-01-01

    Clustering is a fundamental data analysis method. It is widely used for pattern recognition, feature extraction, vector quantization (VQ), image segmentation, function approximation, and data mining. As an unsupervised classification technique, clustering identifies some inherent structures present in a set of objects based on a similarity measure. Clustering methods can be based on statistical model identification (McLachlan & Basford, 1988) or competitive learning. In this paper, we give a comprehensive overview of competitive learning based clustering methods. Importance is attached to a number of competitive learning based clustering neural networks such as the self-organizing map (SOM), the learning vector quantization (LVQ), the neural gas, and the ART model, and clustering algorithms such as the C-means, mountain/subtractive clustering, and fuzzy C-means (FCM) algorithms. Associated topics such as the under-utilization problem, fuzzy clustering, robust clustering, clustering based on non-Euclidean distance measures, supervised clustering, hierarchical clustering as well as cluster validity are also described. Two examples are given to demonstrate the use of the clustering methods.

  10. XCluSim: a visual analytics tool for interactively comparing multiple clustering results of bioinformatics data

    Science.gov (United States)

    2015-01-01

    Background Though cluster analysis has become a routine analytic task for bioinformatics research, it is still arduous for researchers to assess the quality of a clustering result. To select the best clustering method and its parameters for a dataset, researchers have to run multiple clustering algorithms and compare them. However, such a comparison task with multiple clustering results is cognitively demanding and laborious. Results In this paper, we present XCluSim, a visual analytics tool that enables users to interactively compare multiple clustering results based on the Visual Information Seeking Mantra. We build a taxonomy for categorizing existing techniques of clustering results visualization in terms of the Gestalt principles of grouping. Using the taxonomy, we choose the most appropriate interactive visualizations for presenting individual clustering results from different types of clustering algorithms. The efficacy of XCluSim is shown through case studies with a bioinformatician. Conclusions Compared to other relevant tools, XCluSim enables users to compare multiple clustering results in a more scalable manner. Moreover, XCluSim supports diverse clustering algorithms and dedicated visualizations and interactions for different types of clustering results, allowing more effective exploration of details on demand. Through case studies with a bioinformatics researcher, we received positive feedback on the functionalities of XCluSim, including its ability to help identify stably clustered items across multiple clustering results. PMID:26328893

  11. Large Crater Clustering tool

    Science.gov (United States)

    Laura, Jason; Skinner, James A.; Hunter, Marc A.

    2017-08-01

    In this paper we present the Large Crater Clustering (LCC) tool set, an ArcGIS plugin that supports the quantitative approximation of a primary impact location from user-identified locations of possible secondary impact craters or the long-axes of clustered secondary craters. The identification of primary impact craters directly supports planetary geologic mapping and topical science studies where the chronostratigraphic age of some geologic units may be known, but more distant features have questionable geologic ages. Previous works (e.g., McEwen et al., 2005; Dundas and McEwen, 2007) have shown that the source of secondary impact craters can be estimated from secondary impact craters. This work adapts those methods into a statistically robust tool set. We describe the four individual tools within the LCC tool set to support: (1) processing individually digitized point observations (craters), (2) estimating the directional distribution of a clustered set of craters, back projecting the potential flight paths (crater clusters or linearly approximated catenae or lineaments), (3) intersecting projected paths, and (4) intersecting back-projected trajectories to approximate the local of potential source primary craters. We present two case studies using secondary impact features mapped in two regions of Mars. We demonstrate that the tool is able to quantitatively identify primary impacts and supports the improved qualitative interpretation of potential secondary crater flight trajectories.

  12. PVM Support for Clusters

    Science.gov (United States)

    Springer, P.

    2000-01-01

    The latest version of PVM (3.4.3) now contains support for a PC cluster running Linux, also known as a Beowulf system. A PVM user of a computer outside the Beowulf system can add the Beowulf as a single machine.

  13. Size selected metal clusters

    Indian Academy of Sciences (India)

    Soft Landing and Fragmentation of Small Clusters Deposited in Noble-Gas Films. Harbich, W.; Fedrigo, S.; Buttet, J. Phys. Rev. B 1998, 58, 7428 ... When gold is not noble: Nanoscale gold catalysts. Sanchez A, Abbet S, Heiz U J. Phys. Chem. A. 1999, 103, 9573.

  14. Structures of Mn clusters

    Indian Academy of Sciences (India)

    Unknown

    agreement about this), while Mn3–Mn8 are clearly ferro- magnetic (Pederson et al 1998; Nayak et al 1998), and the most stable bulk structure, α Mn, is an antiferromag- net. A recent Stern–Gerlach study by Knickelbein (2001) has added fresh interest to the study of Mn. The experi- mental results show that clusters in the ...

  15. Greedy subspace clustering.

    Science.gov (United States)

    2016-09-01

    We consider the problem of subspace clustering: given points that lie on or near the union of many low-dimensional linear subspaces, recover the subspaces. To this end, one first identifies sets of points close to the same subspace and uses the sets ...

  16. On small clusters

    International Nuclear Information System (INIS)

    Bernardes, N.

    1984-01-01

    A discussion is presented of zero-point motion effects on the binding energy of a small cluster of identical particles interacting through short range attractive-repulsive forces. The model is appropriate to a discussion of both Van der Waals as well as nuclear forces. (Author) [pt

  17. Clustering in Ethiopia

    African Journals Online (AJOL)

    Background: The importance of local variations in patterns of health and disease are increasingly recognised, but, particularly in the case of tropical infections, available methods and resources for characterising disease clusters in time and space are limited. Whilst the Global Positioning System. (GPS) allows accurate and ...

  18. Hardness of Clustering

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Hardness of Clustering. Both k-means and k-medians intractable (when n and d are both inputs even for k =2). The best known deterministic algorithms. are based on Voronoi partitioning that. takes about time. Need for approximation – “close” to optimal.

  19. Structures of Mn clusters

    Indian Academy of Sciences (India)

    Unknown

    Mn clusters were studied with a planewave method employing ultrasoft ... using quasi Newton–Raphson and conjugate gradient methods. The optimizations were deemed sufficiently converged when the forces were about 1 meV/Å. The net magnetic moments were ... with LCAO-type local moments. Differing geometries ...

  20. Extended Fuzzy Clustering Algorithms

    NARCIS (Netherlands)

    U. Kaymak (Uzay); M. Setnes

    2000-01-01

    textabstractFuzzy clustering is a widely applied method for obtaining fuzzy models from data. It has been applied successfully in various fields including finance and marketing. Despite the successful applications, there are a number of issues that must be dealt with in practical applications of

  1. Cluster Decline and Resilience

    DEFF Research Database (Denmark)

    Østergaard, Christian Richter; Park, Eun Kyung

    -2011. Our longitudinal study reveals that technological lock-in and exit of key firms have contributed to impairment of the cluster’s resilience in adapting to disruptions. Entrepreneurship has a positive effect on cluster resilience, while multinational companies have contradicting effects by bringing...

  2. Emergence of regional clusters

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Østergaard, Christian Richter; Dalum, Bent

    2010-01-01

    , networks, labour market pooling and specialised suppliers). However, these factors are not sufficient to explain the early formation of clusters. The dominant theories focus more on explaining ex-post dynamics than their early development. This chapter focuses on the early phase and uses an alternative...

  3. Barbara Storck: Erzählte Enge. Raum und Weiblichkeit in französischen Erzähltexten des 18. und frühen 19. Jahrhunderts. Heidelberg: Universitätsverlag Winter 2009.

    Directory of Open Access Journals (Sweden)

    Zuzanna Aleksandra Jakubowski

    2009-11-01

    Full Text Available Barbara Storck untersucht in ihrer Arbeit die geschlechtsspezifischen Semantisierung literarischer Räume in Erzähltexten Denis Diderots, Jean-Jacques Rousseaus, Mme de Genlis’, Mme de Staëls und Charles Nodiers. Im Zentrum steht dabei das Motiv der räumlichen Enge, insbesondere das der eingeschlossenen Frau. Zielsetzung ist die Erforschung der weiblichen Subjektkonstituierung durch literarische Räume. Leider bleibt eine geschlechteranalytische Perspektive − zugunsten der Darstellung einer Vielzahl ins Verhältnis zur Subjekt-Raum-Konstitution gesetzter zeitgenössischer Diskurse − wenig entwickelt.In her work, Barbara Storck examines the gender-specific semantics of literary spaces in narrative texts by Denis Diderot, Jean-Jacques Rousseau, Mme de Genlis, Mme de Staël, and Charles Nodier. Central to her examination is the motif of spatial constriction and in particular that of the enclosed woman. The goal of the investigation is to uncover the constitution of the female subject through literary spaces. Unfortunately there is little development of a gender analytical perspective – to the benefit, however, of the presentation of multiple contemporary discourses on subject-space constitution.

  4. On the preequilibrium emission of clusters

    Energy Technology Data Exchange (ETDEWEB)

    Lunev, V.P.; Masterov, V.S.; Pronyaev, A.V. [Institute of Physics and Power Engineering, Obninsk (Russian Federation)] [and others

    1995-10-01

    An approach for the description of the preequilibrium emission of light composite particles in the framework of the exciton model is proposed. The description is analogous to the Iwamoto-Harada (I-H) model in which formation factors (FF) of clusters are obtained and the possibility of pick up process is taken into account. In the model proposed phase-space volume corresponding some arbitrary type of cluster with fixed excitation energies of nucleons picked up below and above Fermi Surface (FS) is calculated. This allows the authors to obtain the correct distribution of excitation energy between particle and hole degrees of freedom in the final state density of system: compound nucleus - cluster. The simple factorized form of the final state density of system can be obtained by introducing the average values of excitation energy of cluster constituent particles. The result of I-H treatment is valid only if one neglects the hole energy of picked up m particles, and thus it results in the overestimation of final states density and correspondingly overestimates cross-sections in comparison with the approach proposed. The numerical calculations of modified formation factors (MFF) of alpha particle and tritium are performed.

  5. Space Structure and Clustering of Categorical Data.

    Science.gov (United States)

    Qian, Yuhua; Li, Feijiang; Liang, Jiye; Liu, Bing; Dang, Chuangyin

    2016-10-01

    Learning from categorical data plays a fundamental role in such areas as pattern recognition, machine learning, data mining, and knowledge discovery. To effectively discover the group structure inherent in a set of categorical objects, many categorical clustering algorithms have been developed in the literature, among which k -modes-type algorithms are very representative because of their good performance. Nevertheless, there is still much room for improving their clustering performance in comparison with the clustering algorithms for the numeric data. This may arise from the fact that the categorical data lack a clear space structure as that of the numeric data. To address this issue, we propose, in this paper, a novel data-representation scheme for the categorical data, which maps a set of categorical objects into a Euclidean space. Based on the data-representation scheme, a general framework for space structure based categorical clustering algorithms (SBC) is designed. This framework together with the applications of two kinds of dissimilarities leads two versions of the SBC-type algorithms. To verify the performance of the SBC-type algorithms, we employ as references four representative algorithms of the k -modes-type algorithms. Experiments show that the proposed SBC-type algorithms significantly outperform the k -modes-type algorithms.

  6. Galaxy Clustering and Merging

    Science.gov (United States)

    Wen, Z. L.

    2011-09-01

    Cosmic structure formation and galaxy evolution are important subjects in astrophysics. The thesis consists of two parts: (1) identification of galaxy clusters and studies of their properties; (2) identification of the mergers of luminous early-type galaxies and gravitational waves (GWs). Most of the galaxy clusters in the previous catalogs have redshifts z≤0.3 with richnesses not well determined. Using the photometric redshifts of galaxies from the Sixth Data Release of Sloan Digital Sky Survey (SDSS DR6), we identify 39716 clusters in the redshift range of 0.05contamination rate and the completeness of member galaxies are found to be ˜20% and ∼90%, respectively. Monte Carlo simulations show that the cluster detection rate is larger than 90% for the massive (M_{200}>2×10^{14} M_{⊙}) clusters with z≤0.42. The false detection rate is ˜5%. We obtain the richness, the summed luminosity and the gross galaxy number. They are tightly correlated with the X-ray luminosity and the temperature of clusters. The cluster mass is also found to be tightly related to the richness and summed luminosity in the form of M_{200}∝ R^{1.90±0.04} and M_{200}∝ L_r^{1.64±0.03}, respectively. In addition, 790 new candidates of X-ray clusters are found by cross-identification of our clusters with the unidentified source list of the ROSAT X-ray survey. By visual inspections of the detected clusters, we recognize 13 gravitational lensing candidates. Among all the candidates, four can be sure strong lensing systems even without further spectroscopic identification, five are more probable and four are possible lenses. In the second part, we discuss the merger rates of luminous early-type galaxies and GWs from the mergers of supermassive black holes (SMBHs). The merger rates of massive galaxies in the local universe are still not clear so far. We select a large sample (1209) of close pairs of galaxies with projected separations 7 kpc

  7. Cluster analysis of autoantibodies in 852 patients with systemic lupus erythematosus from a single center.

    Science.gov (United States)

    Artim-Esen, Bahar; Çene, Erhan; Şahinkaya, Yasemin; Ertan, Semra; Pehlivan, Özlem; Kamali, Sevil; Gül, Ahmet; Öcal, Lale; Aral, Orhan; Inanç, Murat

    2014-07-01

    Associations between autoantibodies and clinical features have been described in systemic lupus erythematosus (SLE). Herein, we aimed to define autoantibody clusters and their clinical correlations in a large cohort of patients with SLE. We analyzed 852 patients with SLE who attended our clinic. Seven autoantibodies were selected for cluster analysis: anti-DNA, anti-Sm, anti-RNP, anticardiolipin (aCL) immunoglobulin (Ig)G or IgM, lupus anticoagulant (LAC), anti-Ro, and anti-La. Two-step clustering and Kaplan-Meier survival analyses were used. Five clusters were identified. A cluster consisted of patients with only anti-dsDNA antibodies, a cluster of anti-Sm and anti-RNP, a cluster of aCL IgG/M and LAC, and a cluster of anti-Ro and anti-La antibodies. Analysis revealed 1 more cluster that consisted of patients who did not belong to any of the clusters formed by antibodies chosen for cluster analysis. Sm/RNP cluster had significantly higher incidence of pulmonary hypertension and Raynaud phenomenon. DsDNA cluster had the highest incidence of renal involvement. In the aCL/LAC cluster, there were significantly more patients with neuropsychiatric involvement, antiphospholipid syndrome, autoimmune hemolytic anemia, and thrombocytopenia. According to the Systemic Lupus International Collaborating Clinics damage index, the highest frequency of damage was in the aCL/LAC cluster. Comparison of 10 and 20 years survival showed reduced survival in the aCL/LAC cluster. This study supports the existence of autoantibody clusters with distinct clinical features in SLE and shows that forming clinical subsets according to autoantibody clusters may be useful in predicting the outcome of the disease. Autoantibody clusters in SLE may exhibit differences according to the clinical setting or population.

  8. The next generation Virgo cluster survey. VIII. The spatial distribution of globular clusters in the Virgo cluster

    Energy Technology Data Exchange (ETDEWEB)

    Durrell, Patrick R.; Accetta, Katharine [Department of Physics and Astronomy, Youngstown State University, Youngstown, OH 44555 (United States); Côté, Patrick; Blakeslee, John P.; Ferrarese, Laura; McConnachie, Alan; Gwyn, Stephen [Herzberg Astronomy and Astrophysics, National Research Council, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Peng, Eric W.; Zhang, Hongxin [Department of Astronomy, Peking University, Beijing 100871 (China); Mihos, J. Christopher [Department of Astronomy, Case Western Reserve University, Cleveland, OH 44106 (United States); Puzia, Thomas H.; Jordán, Andrés [Institute of Astrophysics, Pontificia Universidad Catolica, Av. Vicu' a Mackenna 4860, Macul 7820436, Santiago (Chile); Lançon, Ariane [Observatoire astronomique de Strasbourg, Université de Strasbourg, CNRS, UMR 7550, 11 rue de l' Université, F-67000 Strasbourg (France); Liu, Chengze [Center for Astronomy and Astrophysics, Department of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Cuillandre, Jean-Charles [Canada-France-Hawaii Telescope Corporation, Kamuela, HI 96743 (United States); Boissier, Samuel; Boselli, Alessandro [Aix Marseille Université, CNRS, LAM (Laboratoire d' Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France); Courteau, Stéphane [Department of Physics, Engineering Physics and Astronomy, Queen' s University, Kingston, ON K7L 3N6 (Canada); Duc, Pierre-Alain [AIM Paris Saclay, CNRS/INSU, CEA/Irfu, Université Paris Diderot, Orme des Merisiers, F-91191 Gif sur Yvette cedex (France); Emsellem, Eric [Université de Lyon 1, CRAL, Observatoire de Lyon, 9 av. Charles André, F-69230 Saint-Genis Laval (France); CNRS, UMR 5574, ENS de Lyon (France); and others

    2014-10-20

    We report on a large-scale study of the distribution of globular clusters (GCs) throughout the Virgo cluster, based on photometry from the Next Generation Virgo Cluster Survey (NGVS), a large imaging survey covering Virgo's primary subclusters (Virgo A = M87 and Virgo B = M49) out to their virial radii. Using the g{sub o}{sup ′}, (g' – i') {sub o} color-magnitude diagram of unresolved and marginally resolved sources within the NGVS, we have constructed two-dimensional maps of the (irregular) GC distribution over 100 deg{sup 2} to a depth of g{sub o}{sup ′} = 24. We present the clearest evidence to date showing the difference in concentration between red and blue GCs over the full extent of the cluster, where the red (more metal-rich) GCs are largely located around the massive early-type galaxies in Virgo, while the blue (metal-poor) GCs have a much more extended spatial distribution with significant populations still present beyond 83' (∼215 kpc) along the major axes of both M49 and M87. A comparison of our GC maps to the diffuse light in the outermost regions of M49 and M87 show remarkable agreement in the shape, ellipticity, and boxiness of both luminous systems. We also find evidence for spatial enhancements of GCs surrounding M87 that may be indicative of recent interactions or an ongoing merger history. We compare the GC map to that of the locations of Virgo galaxies and the X-ray intracluster gas, and find generally good agreement between these various baryonic structures. We calculate the Virgo cluster contains a total population of N {sub GC} = 67, 300 ± 14, 400, of which 35% are located in M87 and M49 alone. For the first time, we compute a cluster-wide specific frequency S {sub N,} {sub CL} = 2.8 ± 0.7, after correcting for Virgo's diffuse light. We also find a GC-to-baryonic mass fraction ε {sub b} = 5.7 ± 1.1 × 10{sup –4} and a GC-to-total cluster mass formation efficiency ε {sub t} = 2.9 ± 0.5 × 10{sup –5

  9. Cluster model of the nucleus

    International Nuclear Information System (INIS)

    Horiuchi, H.; Ikeda, K.

    1986-01-01

    This article reviews the development of the cluster model study. The stress is put on two points; one is how the cluster structure has come to be regarded as a fundamental structure in light nuclei together with the shell-model structure, and the other is how at present the cluster model is extended to and connected with the studies of the various subjects many of which are in the neighbouring fields. The authors the present the main theme with detailed explanations of the fundamentals of the microscopic cluster model which have promoted the development of the cluster mode. Examples of the microscopic cluster model study of light nuclear structure are given

  10. Benchmark of a Cubieboard cluster

    Science.gov (United States)

    Schnepf, M. J.; Gudu, D.; Rische, B.; Fischer, M.; Jung, C.; Hardt, M.

    2015-12-01

    We built a cluster of ARM-based Cubieboards2 which has a SATA interface to connect a harddrive. This cluster was set up as a storage system using Ceph and as a compute cluster for high energy physics analyses. To study the performance in these applications, we ran two benchmarks on this cluster. We also checked the energy efficiency of the cluster using the preseted benchmarks. Performance and energy efficency of our cluster were compared with a network-attached storage (NAS), and with a desktop PC.

  11. TreeCluster: Massively scalable transmission clustering using phylogenetic trees

    OpenAIRE

    Moshiri, Alexander

    2018-01-01

    Background: The ability to infer transmission clusters from molecular data is critical to designing and evaluating viral control strategies. Viral sequencing datasets are growing rapidly, but standard methods of transmission cluster inference do not scale well beyond thousands of sequences. Results: I present TreeCluster, a cross-platform tool that performs transmission cluster inference on a given phylogenetic tree orders of magnitude faster than existing inference methods and supports multi...

  12. Structure and mass segregation in Galactic stellar clusters

    Science.gov (United States)

    Dib, Sami; Schmeja, Stefan; Parker, Richard J.

    2018-01-01

    We quantify the structure of a very large number of Galactic open clusters and look for evidence of mass segregation for the most massive stars in the clusters. We characterize the structure and mass segregation ratios of 1276 clusters in the Milky Way Stellar Cluster (MWSC) catalogue containing each at least 40 stars and that are located at a distance of up to ≈2 kpc from the Sun. We use an approach based on the calculation of the minimum spanning tree of the clusters, and for each one of them, we calculate the structure parameter Q and the mass segregation ratio ΛMSR. Our findings indicate that most clusters possess a Q parameter that falls in the range 0.7-0.8 and are thus neither strongly concentrated nor do they show significant substructure. Only 27 per cent can be considered centrally concentrated with Q values >0.8. Of the 1276 clusters, only 14 per cent show indication of significant mass segregation (ΛMSR > 1.5). Furthermore, no correlation is found between the structure of the clusters or the degree of mass segregation with their position in the Galaxy. A comparison of the measured Q values for the young open clusters in the MWSC to N-body numerical simulations that follow the evolution of the Q parameter over the first 10 Myr of the clusters life suggests that the young clusters found in the MWSC catalogue initially possessed local mean volume densities of ρ* ≈ 10-100 M⊙ pc-3.

  13. How are small endohedral silicon clusters stabilized?

    Science.gov (United States)

    Avaltroni, Fabrice; Steinmann, Stephan N; Corminboeuf, Clémence

    2012-11-21

    Clusters in the (Be, B, C)@Si(n)((0,1,2+)) (n = 6-10) series, isoelectronic to Si(n)(2-), present multiple symmetric structures, including rings, cages and open structures, which the doping atom stabilizes using contrasting bonding mechanisms. The most striking feature of these clusters is the absence of electron transfer (for Be) or even the inversion (for B and C) in comparison to classic endohedral metallofullerenes (e.g. from the outer frameworks towards the enclosed atom). The relatively small cavity of the highly symmetric Si(8) cubic cage benefits more strongly from the encapsulation of a boron atom than from the insertion of a too large beryllium atom. Overall, the maximization of multicenter-type bonding, as visualized by the Localized Orbital Locator (LOL), is the key to the stabilization of the small Si(n) cages. Boron offers the best balance between size, electronegativity and delocalized bonding pattern when compared to beryllium and carbon.

  14. Choosing the Number of Clusters in K-Means Clustering

    Science.gov (United States)

    Steinley, Douglas; Brusco, Michael J.

    2011-01-01

    Steinley (2007) provided a lower bound for the sum-of-squares error criterion function used in K-means clustering. In this article, on the basis of the lower bound, the authors propose a method to distinguish between 1 cluster (i.e., a single distribution) versus more than 1 cluster. Additionally, conditional on indicating there are multiple…

  15. Cluster forest based fuzzy logic for massive data clustering

    Science.gov (United States)

    Lahmar, Ines; Ben Ayed, Abdelkarim; Ben Halima, Mohamed; Alimi, Adel M.

    2017-03-01

    This article is focused in developing an improved cluster ensemble method based cluster forests. Cluster forests (CF) is considered as a version of clustering inspired from Random Forests (RF) in the context of clustering for massive data. It aggregates intermediate Fuzzy C-Means (FCM) clustering results via spectral clustering since pseudo-clustering results are presented in the spectral space in order to classify these data sets in the multidimensional data space. One of the main advantages is the use of FCM, which allows building fuzzy membership to all partitions of the datasets due to the fuzzy logic whereas the classical algorithms as K-means permitted to build just hard partitions. In the first place, we ameliorate the CF clustering algorithm with the integration of fuzzy FCM and we compare it with other existing clustering methods. In the second place, we compare K-means and FCM clustering methods with the agglomerative hierarchical clustering (HAC) and other theory presented methods using data benchmarks from UCI repository.

  16. Single-cluster dynamics for the random-cluster model

    NARCIS (Netherlands)

    Deng, Y.; Qian, X.; Blöte, H.W.J.

    2009-01-01

    We formulate a single-cluster Monte Carlo algorithm for the simulation of the random-cluster model. This algorithm is a generalization of the Wolff single-cluster method for the q-state Potts model to noninteger values q>1. Its results for static quantities are in a satisfactory agreement with those

  17. Photoionization Spectroscopy of Clusters

    Science.gov (United States)

    Dao, Phan Danh

    Studies of the electronic energies in van der Waals molecules (sometimes referred to as clusters or complexes) help one unravel the microscopic details of the condensed state. Furthermore, they provide the connection between gas-phase and condensed-phase sciences. To achieve this goal, we undertake (1) the spectroscopic studies of van der Waals complexes; (2) the determination of the ionization energies of van der Waals complexes, as well as of mixed alkali metal clusters (e.g., K(,n)O); and (3) the studies of processes that occur upon and after the ionization of van der Waals molecules (namely, dissociation and intracluster reactions). A brief discussion of the non-equilibrium synthesis of weakly bound molecules is given. The operation and performance of the pulsed supersonic jet are described along with some theoretical considerations. The characteristic features of the technique of laser ionization are presented with emphasis on its performance as a spectroscopic tool. Resonance two-photon ionization and time-of-flight mass spectrometry provide us with the tool to measure the perturbed electronic excited state of van der Waals complexes. In these studies, the chromophore species is an aromatic molecule having a single ring (phenylacetylene and para-xylene); and the "solvent" species are rare gas atoms, as well as a variey of molecules. In the case of chromophore-rare gas complexes, the S(,1) excited state is red-shifted, with respect to the nascent chromophore, and the magnitude of the shift shows a definite dependence on the atomic polarizability. Other salient trends of the measured spectral shifts are also discussed. In the measurement of complex ionization energies, the use of two tunable UV lasers is required. With p-xylene(.)Ar(,n) complexes (n = 1-6), these energies vary almost linearly with the number of atoms. Also discussed in the text are the effects of ionization in a weak DC field. A simple hydrogenic model of field-ionization is experimentally

  18. Structure and bonding in clusters

    International Nuclear Information System (INIS)

    Kumar, V.

    1991-10-01

    We review here the recent progress made in the understanding of the electronic and atomic structure of small clusters of s-p bonded materials using the density functional molecular dynamics technique within the local density approximation. Starting with a brief description of the method, results are presented for alkali metal clusters, clusters of divalent metals such as Mg and Be which show a transition from van der Waals or weak chemical bonding to metallic behaviour as the cluster size grows and clusters of Al, Sn and Sb. In the case of semiconductors, we discuss results for Si, Ge and GaAs clusters. Clusters of other materials such as P, C, S, and Se are also briefly discussed. From these and other available results we suggest the possibility of unique structures for the magic clusters. (author). 69 refs, 7 figs, 1 tab

  19. Eclipsing binaries in open clusters

    DEFF Research Database (Denmark)

    Southworth, John; Clausen, J.V.

    2006-01-01

    Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August......Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August...

  20. CLUSTERING SU GRAFO

    Directory of Open Access Journals (Sweden)

    M. Maravalle

    1992-04-01

    general graphs based on the solution of a sequence of restricted problems where G is replaced by one of its spanning tree ; a complete set of real-life applications and a comparison with a hiernrchical algorithm.

  1. Quantum Annealing for Combinatorial Clustering

    OpenAIRE

    Kumar, Vaibhaw; Bass, Gideon; Tomlin, Casey; Dulny III, Joseph

    2017-01-01

    Clustering is a powerful machine learning technique that groups "similar" data points based on their characteristics. Many clustering algorithms work by approximating the minimization of an objective function, namely the sum of within-the-cluster distances between points. The straightforward approach involves examining all the possible assignments of points to each of the clusters. This approach guarantees the solution will be a global minimum, however the number of possible assignments scale...

  2. Remodularization Analysis Using Semantic Clustering

    OpenAIRE

    Santos, Gustavo; Tulio Valente, Marco; Anquetil, Nicolas

    2014-01-01

    International audience; In this paper, we report an experience on using and adapting Semantic Clustering to evaluate software remodularizations. Semantic Clustering is an approach that relies on information retrieval and clustering techniques to extract sets of similar classes in a system, according to their vocabularies. We adapted Semantic Clustering to support remodularization analysis. We evaluate our adaptation using six real-world remodularizations of four software systems. We report th...

  3. The spatial evaluation of neighborhood clusters of birth defects

    Energy Technology Data Exchange (ETDEWEB)

    Frisch, J.D.

    1990-04-16

    Spatial statistics have recently been applied in epidemiology to evaluate clusters of cancer and birth defects. Their use requires a comparison population, drawn from the population at risk for disease, that may not always be readily available. In this dissertation the plausibility of using data on all birth defects, available from birth defects registries, as a surrogate for the spatial distribution of all live births in the analysis of clusters is assessed. Three spatial statistics that have been applied in epidemiologic investigations of clusters, nearest neighbor distance, average interpoint distance, and average distance to a fixed point, were evaluated by computer simulation for their properties in a unit square, and in a zip code region. Comparison of spatial distributions of live births and birth defects was performed by drawing samples of live births and birth defects from Santa Clara County, determining the street address at birth, geocoding this address and evaluating the resultant maps using various statistical techniques. The proposed method was then demonstrated on a previously confirmed cluster of oral cleft cases. All live births for the neighborhood were geocoded, as were all birth defects. Evaluation of this cluster using the nearest neighbor and average interpoint distance statistics was performed using randomization techniques with both the live births population and the birth defect population as comparison groups. 113 refs., 36 figs., 16 tabs.

  4. Refractory chronic cluster headache

    DEFF Research Database (Denmark)

    Mitsikostas, Dimos D; Edvinsson, Lars; Jensen, Rigmor H

    2014-01-01

    Chronic cluster headache (CCH) often resists to prophylactic pharmaceutical treatments resulting in patients' life damage. In this rare but pragmatic situation escalation to invasive management is needed but framing criteria are lacking. We aimed to reach a consensus for refractory CCH definition...... for clinical and research use. The preparation of the final consensus followed three stages. Internal between authors, a larger between all European Headache Federation members and finally an international one among all investigators that have published clinical studies on cluster headache the last five years....... Eighty-five investigators reached by email. Proposed criteria were in the format of the International Classification of Headache Disorders III-beta (description, criteria, notes, comments and references). Following this evaluation eight drafts were prepared before the final. Twenty-four (28...

  5. Di - lambpha cluster states

    International Nuclear Information System (INIS)

    Motoba, Toshio

    1982-01-01

    The lightest (p, n, Λ) closed-shell hypernucleus sub(ΛΛ) sup(6)He can be considered as a most likely candidate for the unit of hypernuclear cluster structure. First the internal structure of lambpha, α sub(Λ) = sub(ΛΛ) sup(6)He, is investigated by solving the α + Λ + Λ three-body problem microscopically. The compact h. o. wave function (0 s) 6 is found to be a good description for α sub(Λ). Secondly, by using the fully microscopic GCM, we have demonstrated that di - α sub(Λ) cluster states constitute a characteristic rotational band of J = 0 + -- 6 + . The E2 transition rate from particle - stable 2 + to 0 + states is predicted to be 2 - order faster than the weak decay rate of this system. (author)

  6. Arabia Crater Cluster

    Science.gov (United States)

    2004-01-01

    27 May 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of a large field of small craters clustered together in northeastern Arabia Terra. Crater clusters usually result from the secondary impact of debris thrown from a much larger impact or from the break-up and impact of fragments of a large meteor. Each crater has subsequently been partially filled by material that erodes to form a rugged crater floor surface, and the general appearance of each crater has been somewhat eroded and modified, as well. The image is located near 34.7oN, 314.7oW, and covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the lower left.

  7. Cluster knockout reactions

    Indian Academy of Sciences (India)

    2014-04-07

    Apr 7, 2014 ... (figure 2), the corresponding α–α t-matrix effective interactions are seen to be widely different (figure 3). 2. Formalism. The finite-range transition matrix element T n,l. BA in the triple differential cross-section [13], d3σ d 1d 2dE1. = Fkin × Sl × |T n,l. BA (kf 1, kf 2, ki)|2 for the (α, 2α) cluster knockout reactions is ...

  8. Cosmology, Clusters and Calorimeters

    Science.gov (United States)

    Figueroa-Feliciano, Enectali

    2005-01-01

    I will review the current state of Cosmology with Clusters and discuss the application of microcalorimeter arrays to this field. With the launch of Astro-E2 this summer and a slew of new missions being developed, microcalorimeters are the next big thing in x-ray astronomy. I will cover the basics and not-so-basic concepts of microcalorimeter designs and look at the future to see where this technology will go.

  9. Three-atom clusters

    International Nuclear Information System (INIS)

    Pen'kov, F.M.

    1998-01-01

    The Born-Oppenheimer approximation is used to obtain an equation for the effective interaction in three atoms bound by a single electron. For low binding energies in an 'electron + atom' pair, long-range forces arise between the atoms, leading to bound states when the size of the three-atom cluster is a few tens of angstrom. A system made of alkali-metal atoms is considered as an example

  10. On clusters and clustering from atoms to fractals

    CERN Document Server

    Reynolds, PJ

    1993-01-01

    This book attempts to answer why there is so much interest in clusters. Clusters occur on all length scales, and as a result occur in a variety of fields. Clusters are interesting scientifically, but they also have important consequences technologically. The division of the book into three parts roughly separates the field into small, intermediate, and large-scale clusters. Small clusters are the regime of atomic and molecular physics and chemistry. The intermediate regime is the transitional regime, with its characteristics including the onset of bulk-like behavior, growth and aggregation, a

  11. Infrared study of new star cluster candidates associated to dusty globules

    Science.gov (United States)

    Soto King, P.; Barbá, R.; Roman-Lopes, A.; Jaque, M.; Firpo, V.; Nilo, J. L.; Soto, M.; Minniti, D.

    2014-10-01

    We present results from a study of a sample of small star clusters associated to dusty globules and bright-rimmed clouds that have been observed under ESO/Chile public infrared survey Vista Variables in the Vía Láctea (VVV). In this short communication, we analyse the near-infrared properties of a set of four small clusters candidates associated to dark clouds. This sample of clusters associated to dusty globules are selected from the new VVV stellar cluster candidates developed by members of La Serena VVV Group (Barbá et al. 2014). Firstly, we are producing color-color and color-magnitude diagrams for both, cluster candidates and surrounding areas for comparison through PSF photometry. The cluster positions are determined from the morphology on the images and also from the comparison of the observed luminosity function for the cluster candidates and the surrounding star fields. Now, we are working in the procedures to establish the full sample of clusters to be analyzed and methods for subtraction of the star field contamination. These clusters associated to dusty globules are simple laboratories to study the star formation relatively free of the influence of large star-forming regions and populous clusters, and they will be compared with those clusters associated to bright-rimmed globules, which are influenced by the energetic action of nearby O and B massive stars.

  12. Electron localization in water clusters

    International Nuclear Information System (INIS)

    Landman, U.; Barnett, R.N.; Cleveland, C.L.; Jortner, J.

    1987-01-01

    Electron attachment to water clusters was explored by the quantum path integral molecular dynamics method, demonstrating that the energetically favored localization mode involves a surface state of the excess electron, rather than the precursor of the hydrated electron. The cluster size dependence, the energetics and the charge distribution of these novel electron-cluster surface states are explored. 20 refs., 2 figs., 1 tab

  13. Subspace K-means clustering.

    Science.gov (United States)

    Timmerman, Marieke E; Ceulemans, Eva; De Roover, Kim; Van Leeuwen, Karla

    2013-12-01

    To achieve an insightful clustering of multivariate data, we propose subspace K-means. Its central idea is to model the centroids and cluster residuals in reduced spaces, which allows for dealing with a wide range of cluster types and yields rich interpretations of the clusters. We review the existing related clustering methods, including deterministic, stochastic, and unsupervised learning approaches. To evaluate subspace K-means, we performed a comparative simulation study, in which we manipulated the overlap of subspaces, the between-cluster variance, and the error variance. The study shows that the subspace K-means algorithm is sensitive to local minima but that the problem can be reasonably dealt with by using partitions of various cluster procedures as a starting point for the algorithm. Subspace K-means performs very well in recovering the true clustering across all conditions considered and appears to be superior to its competitor methods: K-means, reduced K-means, factorial K-means, mixtures of factor analyzers (MFA), and MCLUST. The best competitor method, MFA, showed a performance similar to that of subspace K-means in easy conditions but deteriorated in more difficult ones. Using data from a study on parental behavior, we show that subspace K-means analysis provides a rich insight into the cluster characteristics, in terms of both the relative positions of the clusters (via the centroids) and the shape of the clusters (via the within-cluster residuals).

  14. Recovery Rate of Clustering Algorithms

    NARCIS (Netherlands)

    Li, Fajie; Klette, Reinhard; Wada, T; Huang, F; Lin, S

    2009-01-01

    This article provides a simple and general way for defining the recovery rate of clustering algorithms using a given family of old clusters for evaluating the performance of the algorithm when calculating a family of new clusters. Under the assumption of dealing with simulated data (i.e., known old

  15. Information Theoretic Subspace Clustering.

    Science.gov (United States)

    He, Ran; Wang, Liang; Sun, Zhenan; Zhang, Yingya; Li, Bo

    2016-12-01

    This paper addresses the problem of grouping the data points sampled from a union of multiple subspaces in the presence of outliers. Information theoretic objective functions are proposed to combine structured low-rank representations (LRRs) to capture the global structure of data and information theoretic measures to handle outliers. In theoretical part, we point out that group sparsity-induced measures ( l 2,1 -norm, l α -norm, and correntropy) can be justified from the viewpoint of half-quadratic (HQ) optimization, which facilitates both convergence study and algorithmic development. In particular, a general formulation is accordingly proposed to unify HQ-based group sparsity methods into a common framework. In algorithmic part, we develop information theoretic subspace clustering methods via correntropy. With the help of Parzen window estimation, correntropy is used to handle either outliers under any distributions or sample-specific errors in data. Pairwise link constraints are further treated as a prior structure of LRRs. Based on the HQ framework, iterative algorithms are developed to solve the nonconvex information theoretic loss functions. Experimental results on three benchmark databases show that our methods can further improve the robustness of LRR subspace clustering and outperform other state-of-the-art subspace clustering methods.

  16. Selective Conversion of Methane by Rh1-Doped Aluminum Oxide Cluster Anions RhAl2O4-: A Comparison with the Reactivity of PtAl2O4.

    Science.gov (United States)

    Li, Ya-Ke; Zhao, Yan-Xia; He, Sheng-Gui

    2018-04-04

    Studying the elementary reactions of single-noble-metal-atom-doped species can give theoretical guidance for the design of related single-atom catalysis. Using a combination of mass spectrometry and density functional theory calculations, the reaction of RhAl 2 O 4 - with the most stable alkane molecule CH 4 under thermal conditions has been studied. The methane tends to be converted into syngas (free H 2 and adsorbed CO) with activation of four C-H bonds. In sharp contrast, formaldehyde was generated in the previously reported reaction of PtAl 2 O 4 - with CH 4 . Density functional theory calculations show that the difference in reactivity between RhAl 2 O 4 - and PtAl 2 O 4 - is found to be due to a higher energy barrier of the third C-H bond activation for the Pt analogue. This work provides the first comparative study on the reactivity of single noble-metal atoms (Rh, Pt) on the same cluster support (Al 2 O 4 - ) and can be helpful for rational design of single-atom catalysts for selective methane conversion.

  17. First-principles calculations of the structural and thermodynamic properties of bcc, fcc and hcp solid solutions in the Al-TM (TM = Ti, Zr and Hf) systems: A comparison of cluster expansion and supercell methods

    International Nuclear Information System (INIS)

    Ghosh, G.; Walle, A. van de; Asta, M.

    2008-01-01

    The thermodynamic properties of solid solutions with body-centered cubic (bcc), face-centered cubic (fcc) and hexagonal close-packed (hcp) structures in the Al-TM (TM = Ti, Zr and Hf) systems are calculated from first-principles using cluster expansion (CE), Monte-Carlo simulation and supercell methods. The 32-atom special quasirandom structure (SQS) supercells are employed to compute properties at 25, 50 and 75 at.% TM compositions, and 64-atom supercells have been employed to compute properties of alloys in the dilute concentration limit (one solute and 63 solvent atoms). In general, the energy of mixing (Δ m E) calculated by CE and dilute supercells agree very well. In the concentrated region, the Δ m E values calculated by CE and SQS methods also agree well in many cases; however, noteworthy discrepancies are found in some cases, which we argue originate from inherent elastic and dynamic instabilities of the relevant parent lattice structures. The importance of short-range order on the calculated values of Δ m E for hcp Al-Ti alloys is demonstrated. We also present calculated results for the composition dependence of the atomic volumes in random solid solutions with bcc, fcc and hcp structures. The properties of solid solutions reported here may be integrated within the CALPHAD formalism to develop reliable thermodynamic databases in order to facilitate: (i) calculations of stable and metastable phase diagrams of binary and multicomponent systems, (ii) alloy design, and (iii) processing of Al-TM-based alloys

  18. A cluster algorithm for jet studies

    International Nuclear Information System (INIS)

    Daum, H.J.; Meyer, H.; Buerger, J.

    1980-10-01

    A procedure is described which determines the number of jets in hadronic final states by means of a cluster algorithm. In addition it yields a measurement of the energy and the direction of each jet. The properties of this method are studied using Monte Carlo simulations of different types of e + e - -annihilation final states. It is shown that in case of 3-jet events direct comparison with the underlying parton structure can be made. Possible further applications of this method are discussed. (orig.)

  19. Support Policies in Clusters: Prioritization of Support Needs by Cluster Members According to Cluster Life Cycle

    Directory of Open Access Journals (Sweden)

    Gulcin Salıngan

    2012-07-01

    Full Text Available Economic development has always been a moving target. Both the national and local governments have been facing the challenge of implementing the effective and efficient economic policy and program in order to best utilize their limited resources. One of the recent approaches in this area is called cluster-based economic analysis and strategy development. This study reviews key literature and some of the cluster based economic policies adopted by different governments. Based on this review, it proposes “the cluster life cycle” as a determining factor to identify the support requirements of clusters. A survey, designed based on literature review of International Cluster support programs, was conducted with 30 participants from 3 clusters with different maturity stage. This paper discusses the results of this study conducted among the cluster members in Eskişehir- Bilecik-Kütahya Region in Turkey on the requirement of the support to foster the development of related clusters.

  20. Dynamics of Stars and Globular Clusters in Galaxy Halos

    NARCIS (Netherlands)

    Romanowsky, Aaron J.; Douglas, Nigel G.; Kuijken, Konrad; Arnaboldi, Magda; Kissler-Patig, Markus; Sharples, Ray M.; Zepf, Stephen E.; Rhode, Katherine L.; Kissler-Patig, M.

    2003-01-01

    We have obtained kinematical data in the halos of the giant ellipticals M49 and M87. These include globular cluster velocities in M49 to 10 R_eff and planetary nebula velocities in M49 and M87 to 4 R_eff. We report initial results, including dynamical comparisons between the diffuse stellar

  1. BVRI CCD photometry of the globular cluster NGC 2808

    International Nuclear Information System (INIS)

    Alcaino, G.; Liller, W.; Alvarado, F.; Wenderoth, E.

    1990-01-01

    As a part of a continuing program, CCD color-magnitude diagrams are presented for the bright globular cluster NGC 2808 in the four colors comprising BVRI. From a comparison of four different CMDs with theoretical isochrones, an age of 16 + or - 2 Gyr is obtained, assuming a value for Fe/H near -1.3. 28 refs

  2. Excited electronic state decomposition mechanisms of clusters of ...

    Indian Academy of Sciences (India)

    In this report, electronically non-adiabatic decomposition pathways of clusters of dimethylnitramine and aluminum (DMNA-Al and DMNA-Al2) are discussed in comparison to isolated dimethylnitramine (DMNA). Electronically excited state processes of DMNA-Al and DMNA-Al2 are explored using the complete active space ...

  3. Quark cluster model of nuclei and lepton scattering results

    International Nuclear Information System (INIS)

    Vary, J.P.; Iowa State Univ. of Science and Technology, Ames

    1984-01-01

    A review of the quark cluster model (QCM) of nuclei is presented along with applications to deep inelastic lepton scattering and elastic lepton scattering experiments. In addition a sample comparison is made with high momentum transfer (p, π) data. The QCM prediction for the ratio of nuclear structure functions in the x > 1 domain is discussed as a critical test of the model

  4. Sparse matrix decompositions for clustering

    OpenAIRE

    Blumensath, Thomas

    2014-01-01

    Clustering can be understood as a matrix decomposition problem, where a feature vector matrix is represented as a product of two matrices, a matrix of cluster centres and a matrix with sparse columns, where each column assigns individual features to one of the cluster centres. This matrix factorisation is the basis of classical clustering methods, such as those based on non-negative matrix factorisation but can also be derived for other methods, such as k-means clustering. In this paper we de...

  5. Cluster Based Text Classification Model

    DEFF Research Database (Denmark)

    Nizamani, Sarwat; Memon, Nasrullah; Wiil, Uffe Kock

    2011-01-01

    We propose a cluster based classification model for suspicious email detection and other text classification tasks. The text classification tasks comprise many training examples that require a complex classification model. Using clusters for classification makes the model simpler and increases......, the classifier is trained on each cluster having reduced dimensionality and less number of examples. The experimental results show that the proposed model outperforms the existing classification models for the task of suspicious email detection and topic categorization on the Reuters-21578 and 20 Newsgroups...... datasets. Our model also outperforms A Decision Cluster Classification (ADCC) and the Decision Cluster Forest Classification (DCFC) models on the Reuters-21578 dataset....

  6. Centroid based clustering of high throughput sequencing reads based on n-mer counts.

    Science.gov (United States)

    Solovyov, Alexander; Lipkin, W Ian

    2013-09-08

    Many problems in computational biology require alignment-free sequence comparisons. One of the common tasks involving sequence comparison is sequence clustering. Here we apply methods of alignment-free comparison (in particular, comparison using sequence composition) to the challenge of sequence clustering. We study several centroid based algorithms for clustering sequences based on word counts. Study of their performance shows that using k-means algorithm with or without the data whitening is efficient from the computational point of view. A higher clustering accuracy can be achieved using the soft expectation maximization method, whereby each sequence is attributed to each cluster with a specific probability. We implement an open source tool for alignment-free clustering. It is publicly available from github: https://github.com/luscinius/afcluster. We show the utility of alignment-free sequence clustering for high throughput sequencing analysis despite its limitations. In particular, it allows one to perform assembly with reduced resources and a minimal loss of quality. The major factor affecting performance of alignment-free read clustering is the length of the read.

  7. Application of fuzzy C-means clustering to geophysical transport

    Science.gov (United States)

    Allshouse, Michael

    2017-11-01

    Lagrangian techniques have been used to identify the underlying structures of time varying flows. The fuzzy C-means trajectory clustering is one such approach, which is based on the partitioning of trajectories into sets that remain close in Euclidean space throughout the interval of study. We apply this method first to an analytic geophysical system to determine a procedure that produces robust clusters and to determine characteristics of systems suitable for fuzzy C-means analysis. One challenge of the method is the initial seeding dependence of clustering results, which requires multiple implementations to confirm robustness. Direct comparison with the spectral clustering method demonstrates the limitations of applying the fuzzy C-means method to systems with a large number of coherent structures. We then apply our procedure to a geophysical fluid dynamics numerical simulation to visualize the dominant mechanism of transport.

  8. A novel clustering algorithm based on quantum games

    International Nuclear Information System (INIS)

    Li Qiang; He Yan; Jiang Jingping

    2009-01-01

    Enormous successes have been made by quantum algorithms during the last decade. In this paper, we combine the quantum game with the problem of data clustering, and then develop a quantum-game-based clustering algorithm, in which data points in a dataset are considered as players who can make decisions and implement quantum strategies in quantum games. After each round of a quantum game, each player's expected payoff is calculated. Later, he uses a link-removing-and-rewiring (LRR) function to change his neighbors and adjust the strength of links connecting to them in order to maximize his payoff. Further, algorithms are discussed and analyzed in two cases of strategies, two payoff matrixes and two LRR functions. Consequently, the simulation results have demonstrated that data points in datasets are clustered reasonably and efficiently, and the clustering algorithms have fast rates of convergence. Moreover, the comparison with other algorithms also provides an indication of the effectiveness of the proposed approach.

  9. Seismic Signal Compression Using Nonparametric Bayesian Dictionary Learning via Clustering

    Directory of Open Access Journals (Sweden)

    Xin Tian

    2017-06-01

    Full Text Available We introduce a seismic signal compression method based on nonparametric Bayesian dictionary learning method via clustering. The seismic data is compressed patch by patch, and the dictionary is learned online. Clustering is introduced for dictionary learning. A set of dictionaries could be generated, and each dictionary is used for one cluster’s sparse coding. In this way, the signals in one cluster could be well represented by their corresponding dictionaries. A nonparametric Bayesian dictionary learning method is used to learn the dictionaries, which naturally infers an appropriate dictionary size for each cluster. A uniform quantizer and an adaptive arithmetic coding algorithm are adopted to code the sparse coefficients. With comparisons to other state-of-the art approaches, the effectiveness of the proposed method could be validated in the experiments.

  10. Bioinformatics Prediction of Polyketide Synthase Gene Clusters from Mycosphaerella fijiensis.

    Directory of Open Access Journals (Sweden)

    Roslyn D Noar

    Full Text Available Mycosphaerella fijiensis, causal agent of black Sigatoka disease of banana, is a Dothideomycete fungus closely related to fungi that produce polyketides important for plant pathogenicity. We utilized the M. fijiensis genome sequence to predict PKS genes and their gene clusters and make bioinformatics predictions about the types of compounds produced by these clusters. Eight PKS gene clusters were identified in the M. fijiensis genome, placing M. fijiensis into the 23rd percentile for the number of PKS genes compared to other Dothideomycetes. Analysis of the PKS domains identified three of the PKS enzymes as non-reducing and two as highly reducing. Gene clusters contained types of genes frequently found in PKS clusters including genes encoding transporters, oxidoreductases, methyltransferases, and non-ribosomal peptide synthases. Phylogenetic analysis identified a putative PKS cluster encoding melanin biosynthesis. None of the other clusters were closely aligned with genes encoding known polyketides, however three of the PKS genes fell into clades with clusters encoding alternapyrone, fumonisin, and solanapyrone produced by Alternaria and Fusarium species. A search for homologs among available genomic sequences from 103 Dothideomycetes identified close homologs (>80% similarity for six of the PKS sequences. One of the PKS sequences was not similar (< 60% similarity to sequences in any of the 103 genomes, suggesting that it encodes a unique compound. Comparison of the M. fijiensis PKS sequences with those of two other banana pathogens, M. musicola and M. eumusae, showed that these two species have close homologs to five of the M. fijiensis PKS sequences, but three others were not found in either species. RT-PCR and RNA-Seq analysis showed that the melanin PKS cluster was down-regulated in infected banana as compared to growth in culture. Three other clusters, however were strongly upregulated during disease development in banana, suggesting that

  11. Bioinformatics Prediction of Polyketide Synthase Gene Clusters from Mycosphaerella fijiensis.

    Science.gov (United States)

    Noar, Roslyn D; Daub, Margaret E

    2016-01-01

    Mycosphaerella fijiensis, causal agent of black Sigatoka disease of banana, is a Dothideomycete fungus closely related to fungi that produce polyketides important for plant pathogenicity. We utilized the M. fijiensis genome sequence to predict PKS genes and their gene clusters and make bioinformatics predictions about the types of compounds produced by these clusters. Eight PKS gene clusters were identified in the M. fijiensis genome, placing M. fijiensis into the 23rd percentile for the number of PKS genes compared to other Dothideomycetes. Analysis of the PKS domains identified three of the PKS enzymes as non-reducing and two as highly reducing. Gene clusters contained types of genes frequently found in PKS clusters including genes encoding transporters, oxidoreductases, methyltransferases, and non-ribosomal peptide synthases. Phylogenetic analysis identified a putative PKS cluster encoding melanin biosynthesis. None of the other clusters were closely aligned with genes encoding known polyketides, however three of the PKS genes fell into clades with clusters encoding alternapyrone, fumonisin, and solanapyrone produced by Alternaria and Fusarium species. A search for homologs among available genomic sequences from 103 Dothideomycetes identified close homologs (>80% similarity) for six of the PKS sequences. One of the PKS sequences was not similar (< 60% similarity) to sequences in any of the 103 genomes, suggesting that it encodes a unique compound. Comparison of the M. fijiensis PKS sequences with those of two other banana pathogens, M. musicola and M. eumusae, showed that these two species have close homologs to five of the M. fijiensis PKS sequences, but three others were not found in either species. RT-PCR and RNA-Seq analysis showed that the melanin PKS cluster was down-regulated in infected banana as compared to growth in culture. Three other clusters, however were strongly upregulated during disease development in banana, suggesting that they may encode

  12. CLASSIFICATION OF IRANIAN NURSES ACCORDING TO THEIR MENTAL HEALTH OUTCOMES USING GHQ-12 QUESTIONNAIRE: A COMPARISON BETWEEN LATENT CLASS ANALYSIS AND K-MEANS CLUSTERING WITH TRADITIONAL SCORING METHOD.

    Science.gov (United States)

    Jamali, Jamshid; Ayatollahi, Seyyed Mohammad Taghi

    2015-10-01

    Nurses constitute the most providers of health care systems. Their mental health can affect the quality of services and patients' satisfaction. General Health Questionnaire (GHQ-12) is a general screening tool used to detect mental disorders. Scoring method and determining thresholds for this questionnaire are debatable and the cut-off points can vary from sample to sample. This study was conducted to estimate the prevalence of mental disorders among Iranian nurses using GHQ-12 and also compare Latent Class Analysis (LCA) and K-means clustering with traditional scoring method. A cross-sectional study was carried out in Fars and Bushehr provinces of southern Iran in 2014. Participants were 771 Iranian nurses, who filled out the GHQ-12 questionnaire. Traditional scoring method, LCA and K-means were used to estimate the prevalence of mental disorder among Iranian nurses. Cohen's kappa statistic was applied to assess the agreement between the LCA and K-means with traditional scoring method of GHQ-12. The nurses with mental disorder by scoring method, LCA and K-mean were 36.3% (n=280), 32.2% (n=248), and 26.5% (n=204), respectively. LCA and logistic regression revealed that the prevalence of mental disorder in females was significantly higher than males. Mental disorder in nurses was in a medium level compared to other people living in Iran. There was a little difference between prevalence of mental disorder estimated by scoring method, K-means and LCA. According to the advantages of LCA than K-means and different results in scoring method, we suggest LCA for classification of Iranian nurses according to their mental health outcomes using GHQ-12 questionnaire.

  13. Ionization of nitrogen cluster beam

    International Nuclear Information System (INIS)

    Yano, Katsuki; Be, S.H.; Enjoji, Hiroshi; Okamoto, Kosuke

    1975-01-01

    A nitrogen cluster beam (neutral particle intensity of 28.6 mAsub(eq)) is ionized by electron collisions in a Bayard-Alpert gauge type ionizer. The extraction efficiency of about 65% is obtained at an electron current of 10 mA with an energy of 50 eV. The mean cluster size produced at a pressure of 663 Torr and temperature of 77.3 K is 2x10 5 molecules per cluster. By the Coulomb repulsion force, multiply ionized cluster ions are broken up into smaller fragments and the cluster ion size reduces to one-fourth at an electron current of 15 mA. Mean neutral cluster sizes depend strongly on the initial degree of saturation PHI 0 and are 2x10 5 , 7x10 4 and 3x10 4 molecules per cluster at PHI 0 's of 0.87, 0.66 and 0.39, respectively. (auth.)

  14. Statistics of sunspot group clusters

    Directory of Open Access Journals (Sweden)

    Getko Ryszarda

    2013-03-01

    Full Text Available The Zubrzycki method is utilized to find all sunspot groups which are close to each other during each Carrington rotation. The sunspot group areas and their positions for the years 1874–2008 are used. The descending, the ascending and the maximum phases of solar cycles for each solar hemisphere are considered separately. To establish the size of the region D where the clusters are searched, the correlation function dependent on the distance between two groups is applied. The method estimates the weighted area of each cluster. The weights dependent on the correlation function of distances between sunspot groups created each cluster. For each cluster the weighted position is also evaluated. The weights dependent on the areas of sunspot groups created a given cluster. The number distribution of the sunspot groups created each cluster and the cluster statistics within different phases of the 11-year cycle and within all considered solar cycles are also presented.

  15. Dense Fe cluster-assembled films by energetic cluster deposition

    International Nuclear Information System (INIS)

    Peng, D.L.; Yamada, H.; Hihara, T.; Uchida, T.; Sumiyama, K.

    2004-01-01

    High-density Fe cluster-assembled films were produced at room temperature by an energetic cluster deposition. Though cluster-assemblies are usually sooty and porous, the present Fe cluster-assembled films are lustrous and dense, revealing a soft magnetic behavior. Size-monodispersed Fe clusters with the mean cluster size d=9 nm were synthesized using a plasma-gas-condensation technique. Ionized clusters are accelerated electrically and deposited onto the substrate together with neutral clusters from the same cluster source. Packing fraction and saturation magnetic flux density increase rapidly and magnetic coercivity decreases remarkably with increasing acceleration voltage. The Fe cluster-assembled film obtained at the acceleration voltage of -20 kV has a packing fraction of 0.86±0.03, saturation magnetic flux density of 1.78±0.05 Wb/m 2 , and coercivity value smaller than 80 A/m. The resistivity at room temperature is ten times larger than that of bulk Fe metal

  16. Convex Clustering: An Attractive Alternative to Hierarchical Clustering

    Science.gov (United States)

    Chen, Gary K.; Chi, Eric C.; Ranola, John Michael O.; Lange, Kenneth

    2015-01-01

    The primary goal in cluster analysis is to discover natural groupings of objects. The field of cluster analysis is crowded with diverse methods that make special assumptions about data and address different scientific aims. Despite its shortcomings in accuracy, hierarchical clustering is the dominant clustering method in bioinformatics. Biologists find the trees constructed by hierarchical clustering visually appealing and in tune with their evolutionary perspective. Hierarchical clustering operates on multiple scales simultaneously. This is essential, for instance, in transcriptome data, where one may be interested in making qualitative inferences about how lower-order relationships like gene modules lead to higher-order relationships like pathways or biological processes. The recently developed method of convex clustering preserves the visual appeal of hierarchical clustering while ameliorating its propensity to make false inferences in the presence of outliers and noise. The solution paths generated by convex clustering reveal relationships between clusters that are hidden by static methods such as k-means clustering. The current paper derives and tests a novel proximal distance algorithm for minimizing the objective function of convex clustering. The algorithm separates parameters, accommodates missing data, and supports prior information on relationships. Our program CONVEXCLUSTER incorporating the algorithm is implemented on ATI and nVidia graphics processing units (GPUs) for maximal speed. Several biological examples illustrate the strengths of convex clustering and the ability of the proximal distance algorithm to handle high-dimensional problems. CONVEXCLUSTER can be freely downloaded from the UCLA Human Genetics web site at http://www.genetics.ucla.edu/software/ PMID:25965340

  17. K-means Clustering: Lloyd's algorithm

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. K-means Clustering: Lloyd's algorithm. Refines clusters iteratively. Cluster points using Voronoi partitioning of the centers; Centroids of the clusters determine the new centers. Bad example k = 3, n =4.

  18. Cross-entropy clustering framework for catchment classification

    Science.gov (United States)

    Tongal, Hakan; Sivakumar, Bellie

    2017-09-01

    There is an increasing interest in catchment classification and regionalization in hydrology, as they are useful for identification of appropriate model complexity and transfer of information from gauged catchments to ungauged ones, among others. This study introduces a nonlinear cross-entropy clustering (CEC) method for classification of catchments. The method specifically considers embedding dimension (m), sample entropy (SampEn), and coefficient of variation (CV) to represent dimensionality, complexity, and variability of the time series, respectively. The method is applied to daily streamflow time series from 217 gauging stations across Australia. The results suggest that a combination of linear and nonlinear parameters (i.e. m, SampEn, and CV), representing different aspects of the underlying dynamics of streamflows, could be useful for determining distinct patterns of flow generation mechanisms within a nonlinear clustering framework. For the 217 streamflow time series, nine hydrologically homogeneous clusters that have distinct patterns of flow regime characteristics and specific dominant hydrological attributes with different climatic features are obtained. Comparison of the results with those obtained using the widely employed k-means clustering method (which results in five clusters, with the loss of some information about the features of the clusters) suggests the superiority of the cross-entropy clustering method. The outcomes from this study provide a useful guideline for employing the nonlinear dynamic approaches based on hydrologic signatures and for gaining an improved understanding of streamflow variability at a large scale.

  19. A diagnostic cluster system for skilled nursing facilities.

    Science.gov (United States)

    Odio, A; Deamer, R L; Cheadle, M; Parker, C E; Herbst, M; Liu, I; Amico, M

    1996-01-01

    Diagnostic cluster systems have been developed to assist in analyzing diagnoses in outpatient and inpatient settings but not in convalescent hospital settings. We developed a diagnostic cluster system for skilled nursing facilities (SNFs) designed to include or capture a greater proportion of such diagnoses than a previously established inpatient diagnostic cluster system. We tested the ability of the new SNF diagnostic cluster system to code diagnoses on records from SNFs in different geographic areas. Then we compared the proportion of admitting diagnoses captured by the new SNF diagnostic cluster system and by a previously established inpatient system. The new diagnostic cluster system captured between 92% and 96% of admitting diagnoses at the study SNFs. There was no statistically significant difference among the facilities in the proportion of diagnoses captured by the new system. By comparison, the previously established inpatient system captured only 59%-65% of these admitting diagnoses. The new system captured significantly more diagnoses than the previously established inpatient system. The new SNF diagnostic cluster system can be used to capture and code diagnostic data from SNFs.

  20. Simulation-based marginal likelihood for cluster strong lensing cosmology

    Science.gov (United States)

    Killedar, M.; Borgani, S.; Fabjan, D.; Dolag, K.; Granato, G.; Meneghetti, M.; Planelles, S.; Ragone-Figueroa, C.

    2018-01-01

    Comparisons between observed and predicted strong lensing properties of galaxy clusters have been routinely used to claim either tension or consistency with Λ cold dark matter cosmology. However, standard approaches to such cosmological tests are unable to quantify the preference for one cosmology over another. We advocate approximating the relevant Bayes factor using a marginal likelihood that is based on the following summary statistic: the posterior probability distribution function for the parameters of the scaling relation between Einstein radii and cluster mass, α and β. We demonstrate, for the first time, a method of estimating the marginal likelihood using the X-ray selected z > 0.5 Massive Cluster Survey clusters as a case in point and employing both N-body and hydrodynamic simulations of clusters. We investigate the uncertainty in this estimate and consequential ability to compare competing cosmologies, which arises from incomplete descriptions of baryonic processes, discrepancies in cluster selection criteria, redshift distribution and dynamical state. The relation between triaxial cluster masses at various overdensities provides a promising alternative to the strong lensing test.