A Novel Automatic Detection System for ECG Arrhythmias Using Maximum Margin Clustering with Immune Evolutionary Algorithm

Directory of Open Access Journals (Sweden)

Bohui Zhu

2013-01-01

Full Text Available This paper presents a novel maximum margin clustering method with immune evolution (IEMMC for automatic diagnosis of electrocardiogram (ECG arrhythmias. This diagnostic system consists of signal processing, feature extraction, and the IEMMC algorithm for clustering of ECG arrhythmias. First, raw ECG signal is processed by an adaptive ECG filter based on wavelet transforms, and waveform of the ECG signal is detected; then, features are extracted from ECG signal to cluster different types of arrhythmias by the IEMMC algorithm. Three types of performance evaluation indicators are used to assess the effect of the IEMMC method for ECG arrhythmias, such as sensitivity, specificity, and accuracy. Compared with K-means and iterSVR algorithms, the IEMMC algorithm reflects better performance not only in clustering result but also in terms of global search ability and convergence ability, which proves its effectiveness for the detection of ECG arrhythmias.

Weakly and strongly polynomial algorithms for computing the maximum decrease in uniform arc capacities

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Ghiyasvand Mehdi

2016-01-01

Full Text Available In this paper, a new problem on a directed network is presented. Let D be a feasible network such that all arc capacities are equal to U. Given a t > 0, the network D with arc capacities U - t is called the t-network. The goal of the problem is to compute the largest t such that the t-network is feasible. First, we present a weakly polynomial time algorithm to solve this problem, which runs in O(log(nU maximum flow computations, where n is the number of nodes. Then, an O(m2n time approach is presented, where m is the number of arcs. Both the weakly and strongly polynomial algorithms are inspired by McCormick and Ervolina (1994.

Developing the fuzzy c-means clustering algorithm based on maximum entropy for multitarget tracking in a cluttered environment

Science.gov (United States)

Chen, Xiao; Li, Yaan; Yu, Jing; Li, Yuxing

2018-01-01

For fast and more effective implementation of tracking multiple targets in a cluttered environment, we propose a multiple targets tracking (MTT) algorithm called maximum entropy fuzzy c-means clustering joint probabilistic data association that combines fuzzy c-means clustering and the joint probabilistic data association (PDA) algorithm. The algorithm uses the membership value to express the probability of the target originating from measurement. The membership value is obtained through fuzzy c-means clustering objective function optimized by the maximum entropy principle. When considering the effect of the public measurement, we use a correction factor to adjust the association probability matrix to estimate the state of the target. As this algorithm avoids confirmation matrix splitting, it can solve the high computational load problem of the joint PDA algorithm. The results of simulations and analysis conducted for tracking neighbor parallel targets and cross targets in a different density cluttered environment show that the proposed algorithm can realize MTT quickly and efficiently in a cluttered environment. Further, the performance of the proposed algorithm remains constant with increasing process noise variance. The proposed algorithm has the advantages of efficiency and low computational load, which can ensure optimum performance when tracking multiple targets in a dense cluttered environment.

Stability of maximum-likelihood-based clustering methods: exploring the backbone of classifications

International Nuclear Information System (INIS)

Mungan, Muhittin; Ramasco, José J

2010-01-01

Components of complex systems are often classified according to the way they interact with each other. In graph theory such groups are known as clusters or communities. Many different techniques have been recently proposed to detect them, some of which involve inference methods using either Bayesian or maximum likelihood approaches. In this paper, we study a statistical model designed for detecting clusters based on connection similarity. The basic assumption of the model is that the graph was generated by a certain grouping of the nodes and an expectation maximization algorithm is employed to infer that grouping. We show that the method admits further development to yield a stability analysis of the groupings that quantifies the extent to which each node influences its neighbors' group membership. Our approach naturally allows for the identification of the key elements responsible for the grouping and their resilience to changes in the network. Given the generality of the assumptions underlying the statistical model, such nodes are likely to play special roles in the original system. We illustrate this point by analyzing several empirical networks for which further information about the properties of the nodes is available. The search and identification of stabilizing nodes constitutes thus a novel technique to characterize the relevance of nodes in complex networks

On the low SNR capacity of maximum ratio combining over rician fading channels with full channel state information

KAUST Repository

Benkhelifa, Fatma; Rezki, Zouheir; Alouini, Mohamed-Slim

2013-01-01

In this letter, we study the ergodic capacity of a maximum ratio combining (MRC) Rician fading channel with full channel state information (CSI) at the transmitter and at the receiver. We focus on the low Signal-to-Noise Ratio (SNR) regime and we show that the capacity scales as L ΩK+L SNRx log(1SNR), where Ω is the expected channel gain per branch, K is the Rician fading factor, and L is the number of diversity branches. We show that one-bit CSI feedback at the transmitter is enough to achieve this capacity using an on-off power control scheme. Our framework can be seen as a generalization of recently established results regarding the fading-channels capacity characterization in the low-SNR regime. © 2012 IEEE.

On the low SNR capacity of maximum ratio combining over rician fading channels with full channel state information

KAUST Repository

Benkhelifa, Fatma

2013-04-01

In this letter, we study the ergodic capacity of a maximum ratio combining (MRC) Rician fading channel with full channel state information (CSI) at the transmitter and at the receiver. We focus on the low Signal-to-Noise Ratio (SNR) regime and we show that the capacity scales as L ΩK+L SNRx log(1SNR), where Ω is the expected channel gain per branch, K is the Rician fading factor, and L is the number of diversity branches. We show that one-bit CSI feedback at the transmitter is enough to achieve this capacity using an on-off power control scheme. Our framework can be seen as a generalization of recently established results regarding the fading-channels capacity characterization in the low-SNR regime. © 2012 IEEE.

Progressive Exponential Clustering-Based Steganography

Directory of Open Access Journals (Sweden)

Li Yue

2010-01-01

Full Text Available Cluster indexing-based steganography is an important branch of data-hiding techniques. Such schemes normally achieve good balance between high embedding capacity and low embedding distortion. However, most cluster indexing-based steganographic schemes utilise less efficient clustering algorithms for embedding data, which causes redundancy and leaves room for increasing the embedding capacity further. In this paper, a new clustering algorithm, called progressive exponential clustering (PEC, is applied to increase the embedding capacity by avoiding redundancy. Meanwhile, a cluster expansion algorithm is also developed in order to further increase the capacity without sacrificing imperceptibility.

Economic feasibility of district heating delivery from industrial excess heat: A case study of a Swedish petrochemical cluster

International Nuclear Information System (INIS)

Morandin, Matteo; Hackl, Roman; Harvey, Simon

2014-01-01

The present work discusses the potential and the economic feasibility of DH (district heating) delivery using industrial excess heat from a petrochemical cluster at the Swedish West Coast. Pinch Analysis was used for estimating the DH capacity targets and for estimating the cost of heat exchanger installation. A discounted cash flow rate of return of 10% was used as a criterion for identifying the minimum yearly DH delivery that should be guaranteed for a given DH capacity at different DH sales prices. The study was conducted for the current scenario in which no heat recovery is achieved between the cluster plants and for a possible future scenario in which 50% of the fuel currently used for heating purposes is saved by increasing the heat recovery at the site. The competition between excess heat export and local energy efficiency measures is also discussed in terms of CO 2 emission consequences. The maximum capacity of DH delivery amounts today to around 235 MW, which reduces to 110 MW in the future scenario of increased site heat recovery. The results of our analysis show that feasible conditions exist that make DH delivery profitable in the entire capacity range. - Highlights: • Pinch Analysis targeting approach and short-cut cost accounting procedure. • Economic analysis for different DH delivery capacities up to maximum targets. • Sensitivity analysis of heat sales prices. • Parallel plants and cluster wide heat collection systems considered. • Competition between cluster internal heat recovery and excess heat export is discussed

The maximum reservoir capacity of soils for persistent organic pollutants: implications for global cycling

International Nuclear Information System (INIS)

Dalla Valle, M.; Jurado, E.; Dachs, J.; Sweetman, A.J.; Jones, K.C.

2005-01-01

The concept of maximum reservoir capacity (MRC), the ratio of the capacities of the surface soil and of the atmospheric mixed layer (AML) to hold chemical under equilibrium conditions, is applied to selected persistent organic pollutants (POPs) in the surface 'skin' (1 mm) of soils. MRC is calculated as a function of soil organic matter (SOM) content and temperature-dependent K OA and mapped globally for selected PCB congeners (PCB-28; -153; -180) and HCB, to identify regions with a higher tendency to retain POPs. It is shown to vary over many orders of magnitude, between compounds, locations and time (seasonally/diurnally). The MRC approach emphasises the very large capacity of soils as a storage compartment for POPs. The theoretical MRC concept is compared to reality and its implications for the global cycling of POPs are discussed. Sharp gradients in soil MRC can exist in mountainous areas and between the land and ocean. Exchanges between oceans and land masses via the atmosphere is likely to be an important driver to the global cycling of these compounds, and net ocean-land transfers could occur in some areas. - Major global terrestrial sinks/stores for POPs are identified and the significance of gradients between them discussed

Measuring galaxy cluster masses with CMB lensing using a Maximum Likelihood estimator: statistical and systematic error budgets for future experiments

Energy Technology Data Exchange (ETDEWEB)

Raghunathan, Srinivasan; Patil, Sanjaykumar; Bianchini, Federico; Reichardt, Christian L. [School of Physics, University of Melbourne, 313 David Caro building, Swanston St and Tin Alley, Parkville VIC 3010 (Australia); Baxter, Eric J. [Department of Physics and Astronomy, University of Pennsylvania, 209 S. 33rd Street, Philadelphia, PA 19104 (United States); Bleem, Lindsey E. [Argonne National Laboratory, High-Energy Physics Division, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Crawford, Thomas M. [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Holder, Gilbert P. [Department of Astronomy and Department of Physics, University of Illinois, 1002 West Green St., Urbana, IL 61801 (United States); Manzotti, Alessandro, E-mail: srinivasan.raghunathan@unimelb.edu.au, E-mail: s.patil2@student.unimelb.edu.au, E-mail: ebax@sas.upenn.edu, E-mail: federico.bianchini@unimelb.edu.au, E-mail: bleeml@uchicago.edu, E-mail: tcrawfor@kicp.uchicago.edu, E-mail: gholder@illinois.edu, E-mail: manzotti@uchicago.edu, E-mail: christian.reichardt@unimelb.edu.au [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)

2017-08-01

We develop a Maximum Likelihood estimator (MLE) to measure the masses of galaxy clusters through the impact of gravitational lensing on the temperature and polarization anisotropies of the cosmic microwave background (CMB). We show that, at low noise levels in temperature, this optimal estimator outperforms the standard quadratic estimator by a factor of two. For polarization, we show that the Stokes Q/U maps can be used instead of the traditional E- and B-mode maps without losing information. We test and quantify the bias in the recovered lensing mass for a comprehensive list of potential systematic errors. Using realistic simulations, we examine the cluster mass uncertainties from CMB-cluster lensing as a function of an experiment's beam size and noise level. We predict the cluster mass uncertainties will be 3 - 6% for SPT-3G, AdvACT, and Simons Array experiments with 10,000 clusters and less than 1% for the CMB-S4 experiment with a sample containing 100,000 clusters. The mass constraints from CMB polarization are very sensitive to the experimental beam size and map noise level: for a factor of three reduction in either the beam size or noise level, the lensing signal-to-noise improves by roughly a factor of two.

Assessment of precast beam-column using capacity demand response spectrum subject to design basis earthquake and maximum considered earthquake

Science.gov (United States)

Ghani, Kay Dora Abd.; Tukiar, Mohd Azuan; Hamid, Nor Hayati Abdul

2017-08-01

Malaysia is surrounded by the tectonic feature of the Sumatera area which consists of two seismically active inter-plate boundaries, namely the Indo-Australian and the Eurasian Plates on the west and the Philippine Plates on the east. Hence, Malaysia experiences tremors from far distant earthquake occurring in Banda Aceh, Nias Island, Padang and other parts of Sumatera Indonesia. In order to predict the safety of precast buildings in Malaysia under near field ground motion the response spectrum analysis could be used for dealing with future earthquake whose specific nature is unknown. This paper aimed to develop of capacity demand response spectrum subject to Design Basis Earthquake (DBE) and Maximum Considered Earthquake (MCE) in order to assess the performance of precast beam column joint. From the capacity-demand response spectrum analysis, it can be concluded that the precast beam-column joints would not survive when subjected to earthquake excitation with surface-wave magnitude, Mw, of more than 5.5 Scale Richter (Type 1 spectra). This means that the beam-column joint which was designed using the current code of practice (BS8110) would be severely damaged when subjected to high earthquake excitation. The capacity-demand response spectrum analysis also shows that the precast beam-column joints in the prototype studied would be severely damaged when subjected to Maximum Considered Earthquake (MCE) with PGA=0.22g having a surface-wave magnitude of more than 5.5 Scale Richter, or Type 1 spectra.

Bayesian modeling of the assimilative capacity component of nutrient total maximum daily loads

Science.gov (United States)

Faulkner, B. R.

2008-08-01

Implementing stream restoration techniques and best management practices to reduce nonpoint source nutrients implies enhancement of the assimilative capacity for the stream system. In this paper, a Bayesian method for evaluating this component of a total maximum daily load (TMDL) load capacity is developed and applied. The joint distribution of nutrient retention metrics from a literature review of 495 measurements was used for Monte Carlo sampling with a process transfer function for nutrient attenuation. Using the resulting histograms of nutrient retention, reference prior distributions were developed for sites in which some of the metrics contributing to the transfer function were measured. Contributing metrics for the prior include stream discharge, cross-sectional area, fraction of storage volume to free stream volume, denitrification rate constant, storage zone mass transfer rate, dispersion coefficient, and others. Confidence of compliance (CC) that any given level of nutrient retention has been achieved is also determined using this approach. The shape of the CC curve is dependent on the metrics measured and serves in part as a measure of the information provided by the metrics to predict nutrient retention. It is also a direct measurement, with a margin of safety, of the fraction of export load that can be reduced through changing retention metrics. For an impaired stream in western Oklahoma, a combination of prior information and measurement of nutrient attenuation was used to illustrate the proposed approach. This method may be considered for TMDL implementation.

Spatial clustering of pixels of a multispectral image

Science.gov (United States)

Conger, James Lynn

2014-08-19

A method and system for clustering the pixels of a multispectral image is provided. A clustering system computes a maximum spectral similarity score for each pixel that indicates the similarity between that pixel and the most similar neighboring. To determine the maximum similarity score for a pixel, the clustering system generates a similarity score between that pixel and each of its neighboring pixels and then selects the similarity score that represents the highest similarity as the maximum similarity score. The clustering system may apply a filtering criterion based on the maximum similarity score so that pixels with similarity scores below a minimum threshold are not clustered. The clustering system changes the current pixel values of the pixels in a cluster based on an averaging of the original pixel values of the pixels in the cluster.

A new approach to hierarchical data analysis: Targeted maximum likelihood estimation for the causal effect of a cluster-level exposure.

Science.gov (United States)

Balzer, Laura B; Zheng, Wenjing; van der Laan, Mark J; Petersen, Maya L

2018-01-01

We often seek to estimate the impact of an exposure naturally occurring or randomly assigned at the cluster-level. For example, the literature on neighborhood determinants of health continues to grow. Likewise, community randomized trials are applied to learn about real-world implementation, sustainability, and population effects of interventions with proven individual-level efficacy. In these settings, individual-level outcomes are correlated due to shared cluster-level factors, including the exposure, as well as social or biological interactions between individuals. To flexibly and efficiently estimate the effect of a cluster-level exposure, we present two targeted maximum likelihood estimators (TMLEs). The first TMLE is developed under a non-parametric causal model, which allows for arbitrary interactions between individuals within a cluster. These interactions include direct transmission of the outcome (i.e. contagion) and influence of one individual's covariates on another's outcome (i.e. covariate interference). The second TMLE is developed under a causal sub-model assuming the cluster-level and individual-specific covariates are sufficient to control for confounding. Simulations compare the alternative estimators and illustrate the potential gains from pairing individual-level risk factors and outcomes during estimation, while avoiding unwarranted assumptions. Our results suggest that estimation under the sub-model can result in bias and misleading inference in an observational setting. Incorporating working assumptions during estimation is more robust than assuming they hold in the underlying causal model. We illustrate our approach with an application to HIV prevention and treatment.

Stopping of hypervelocity clusters in solids

International Nuclear Information System (INIS)

Anders, Christian; Ziegenhain, Gerolf; Urbassek, Herbert M; Bringa, Eduardo M

2011-01-01

Using molecular-dynamics simulations, we study the processes underlying the stopping of energetic clusters upon impact in matter. We investigate self-bombardment of both a metallic (Cu) and a van-der-Waals bonded (frozen Ar) target. Clusters with sizes up to N = 10 4 atoms and with energies per atom of E/N = 0.1-1600 eV atom -1 were studied. We find that the stopping force exerted on a cluster follows an N 2/3 -dependence with cluster size N; thus large clusters experience less stopping than equi-velocity atoms. In the course of being stopped, the cluster is strongly deformed and attains a roughly pancake shape. Due to the cluster inertia, maximum deformation occurs later than the maximum stopping force. The time scale of projectile stopping is set by t 0 , the time the cluster needs to cover its own diameter before impacting the target; it thus depends on both cluster size and velocity. The time when the cluster experiences its maximum stopping force is around (0.7-0.8)t 0 . We find that the cluster is deformed with huge strain rates of around 1/2t 0 ; this amounts to 10 11 -10 13 s -1 for the cases studied here. (paper)

GAS SURFACE DENSITY, STAR FORMATION RATE SURFACE DENSITY, AND THE MAXIMUM MASS OF YOUNG STAR CLUSTERS IN A DISK GALAXY. II. THE GRAND-DESIGN GALAXY M51

International Nuclear Information System (INIS)

González-Lópezlira, Rosa A.; Pflamm-Altenburg, Jan; Kroupa, Pavel

2013-01-01

We analyze the relationship between maximum cluster mass and surface densities of total gas (Σ gas ), molecular gas (Σ H 2 ), neutral gas (Σ H I ), and star formation rate (Σ SFR ) in the grand-design galaxy M51, using published gas data and a catalog of masses, ages, and reddenings of more than 1800 star clusters in its disk, of which 223 are above the cluster mass distribution function completeness limit. By comparing the two-dimensional distribution of cluster masses and gas surface densities, we find for clusters older than 25 Myr that M 3rd ∝Σ H I 0.4±0.2 , whereM 3rd is the median of the five most massive clusters. There is no correlation withΣ gas ,Σ H2 , orΣ SFR . For clusters younger than 10 Myr, M 3rd ∝Σ H I 0.6±0.1 and M 3rd ∝Σ gas 0.5±0.2 ; there is no correlation with either Σ H 2 orΣ SFR . The results could hardly be more different from those found for clusters younger than 25 Myr in M33. For the flocculent galaxy M33, there is no correlation between maximum cluster mass and neutral gas, but we have determined M 3rd ∝Σ gas 3.8±0.3 , M 3rd ∝Σ H 2 1.2±0.1 , and M 3rd ∝Σ SFR 0.9±0.1 . For the older sample in M51, the lack of tight correlations is probably due to the combination of strong azimuthal variations in the surface densities of gas and star formation rate, and the cluster ages. These two facts mean that neither the azimuthal average of the surface densities at a given radius nor the surface densities at the present-day location of a stellar cluster represent the true surface densities at the place and time of cluster formation. In the case of the younger sample, even if the clusters have not yet traveled too far from their birth sites, the poor resolution of the radio data compared to the physical sizes of the clusters results in measuredΣ that are likely quite diluted compared to the actual densities relevant for the formation of the clusters.

Maximum capacity model of grid-connected multi-wind farms considering static security constraints in electrical grids

International Nuclear Information System (INIS)

Zhou, W; Oodo, S O; He, H; Qiu, G Y

2013-01-01

An increasing interest in wind energy and the advance of related technologies have increased the connection of wind power generation into electrical grids. This paper proposes an optimization model for determining the maximum capacity of wind farms in a power system. In this model, generator power output limits, voltage limits and thermal limits of branches in the grid system were considered in order to limit the steady-state security influence of wind generators on the power system. The optimization model was solved by a nonlinear primal-dual interior-point method. An IEEE-30 bus system with two wind farms was tested through simulation studies, plus an analysis conducted to verify the effectiveness of the proposed model. The results indicated that the model is efficient and reasonable.

Maximum capacity model of grid-connected multi-wind farms considering static security constraints in electrical grids

Science.gov (United States)

Zhou, W.; Qiu, G. Y.; Oodo, S. O.; He, H.

2013-03-01

An increasing interest in wind energy and the advance of related technologies have increased the connection of wind power generation into electrical grids. This paper proposes an optimization model for determining the maximum capacity of wind farms in a power system. In this model, generator power output limits, voltage limits and thermal limits of branches in the grid system were considered in order to limit the steady-state security influence of wind generators on the power system. The optimization model was solved by a nonlinear primal-dual interior-point method. An IEEE-30 bus system with two wind farms was tested through simulation studies, plus an analysis conducted to verify the effectiveness of the proposed model. The results indicated that the model is efficient and reasonable.

The capacity limitations of orientation summary statistics

Science.gov (United States)

Attarha, Mouna; Moore, Cathleen M.

2015-01-01

The simultaneous–sequential method was used to test the processing capacity of establishing mean orientation summaries. Four clusters of oriented Gabor patches were presented in the peripheral visual field. One of the clusters had a mean orientation that was tilted either left or right while the mean orientations of the other three clusters were roughly vertical. All four clusters were presented at the same time in the simultaneous condition whereas the clusters appeared in temporal subsets of two in the sequential condition. Performance was lower when the means of all four clusters had to be processed concurrently than when only two had to be processed in the same amount of time. The advantage for establishing fewer summaries at a given time indicates that the processing of mean orientation engages limited-capacity processes (Experiment 1). This limitation cannot be attributed to crowding, low target-distractor discriminability, or a limited-capacity comparison process (Experiments 2 and 3). In contrast to the limitations of establishing multiple summary representations, establishing a single summary representation unfolds without interference (Experiment 4). When interpreted in the context of recent work on the capacity of summary statistics, these findings encourage reevaluation of the view that early visual perception consists of summary statistic representations that unfold independently across multiple areas of the visual field. PMID:25810160

Hydrogen storage capacity of titanium met-cars

International Nuclear Information System (INIS)

Akman, N; Durgun, E; Yildirim, T; Ciraci, S

2006-01-01

The adsorption of hydrogen molecules on the titanium metallocarbohedryne (met-car) cluster has been investigated by using the first-principles plane wave method. We have found that, while a single Ti atom at the corner can bind up to three hydrogen molecules, a single Ti atom on the surface of the cluster can bind only one hydrogen molecule. Accordingly, a Ti 8 C 12 met-car can bind up to 16 H 2 molecules and hence can be considered as a high-capacity hydrogen storage medium. Strong interaction between two met-car clusters leading to the dimer formation can affect H 2 storage capacity slightly. Increasing the storage capacity by directly inserting H 2 into the met-car or by functionalizing it with an Na atom have been explored. It is found that the insertion of neither an H 2 molecule nor an Na atom could further promote the H 2 storage capacity of a Ti 8 C 12 cluster. We have also tested the stability of the H 2 -adsorbed Ti 8 C 12 met-car with ab initio molecular dynamics calculations which have been carried out at room temperature

Liposomal solubilization of new 3-hydroxy-quinolinone derivatives with promising anticancer activity: a screening method to identify maximum incorporation capacity

DEFF Research Database (Denmark)

Di Cagno, Massimiliano; Styskala, Jakub; Hlaváč, Jan

2011-01-01

Four new 3-hydroxy-quinolinone derivatives with promising anticancer activity could be solubilized using liposomes as vehicle to an extent that allows their in vitro and in vivo testing without use of toxic solvent(s). A screening method to identify the maximum incorporation capacity of hydrophobic......, resulting in a 200-500-fold increase in apparent solubility. Drug-to-lipid ratios in the range of 2-5 µg/mg were obtained. Interestingly, the four quinolinone derivatives have shown different association tendencies with liposomes, probably due to the physicochemical properties of the different group bonded...

Capacity Expansion and Reliability Evaluation on the Networks Flows with Continuous Stochastic Functional Capacity

Directory of Open Access Journals (Sweden)

F. Hamzezadeh

2014-01-01

Full Text Available In many systems such as computer network, fuel distribution, and transportation system, it is necessary to change the capacity of some arcs in order to increase maximum flow value from source s to sink t, while the capacity change incurs minimum cost. In real-time networks, some factors cause loss of arc’s flow. For example, in some flow distribution systems, evaporation, erosion or sediment in pipes waste the flow. Here we define a real capacity, or the so-called functional capacity, which is the operational capacity of an arc. In other words, the functional capacity of an arc equals the possible maximum flow that may pass through the arc. Increasing the functional arcs capacities incurs some cost. There is a certain resource available to cover the costs. First, we construct a mathematical model to minimize the total cost of expanding the functional capacities to the required levels. Then, we consider the loss of flow on each arc as a stochastic variable and compute the system reliability.

Spanning Tree Based Attribute Clustering

DEFF Research Database (Denmark)

Zeng, Yifeng; Jorge, Cordero Hernandez

2009-01-01

Attribute clustering has been previously employed to detect statistical dependence between subsets of variables. We propose a novel attribute clustering algorithm motivated by research of complex networks, called the Star Discovery algorithm. The algorithm partitions and indirectly discards...... 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...

Peculiar features of heat capacity for Cu and Ni nanoclusters

International Nuclear Information System (INIS)

Gafner, S. L.; Redel, L. V.; Gafner, Yu. Ya.; Samsonov, V. M.

2011-01-01

The heat capacity of copper and nickel clusters (from 2 to 6 nm in diameter) was investigated in the temperature range 200–800 K using molecular dynamics method and a modified tight-binding potential. The simulation results demonstrate a very good agreement with the available experimental data at T = 200 K and a fairy good agreement at higher temperatures. A number of regular trends are revealed in computer experiments which agree with the corresponding theoretical predictions. A conclusion is made that in the case of single free clusters the heat capacity may exceed the capacity of the corresponding bulk material. It is found that at 200 K, the copper nanocluster (D = 6 nm) heat capacity is higher by 10% and for nickel cluster by 13%. The difference diminishes with increasing the nanoparticles size proportionally to the relative number of surface atoms. A conclusion is made that very high values of the nanostructure heat capacity observed in laboratory experiments should not be attributed to free clusters, i.e., the effect in question is caused by other reasons.

Intercalating graphene with clusters of Fe3O4 nanocrystals for electrochemical supercapacitors

Science.gov (United States)

Ke, Qingqing; Tang, Chunhua; Liu, Yanqiong; Liu, Huajun; Wang, John

2014-04-01

A hierarchical nanostructure consisting of graphene sheets intercalated by clusters of Fe3O4 nanocystals is developed for high-performance supercapacitor electrode. Here we show that the negatively charged graphene oxide (GO) and positively charged Fe3O4 clusters enable a strong electrostatic interaction, generating a hierarchical 3D nanostructure, which gives rise to the intercalated composites through a rational hydrothermal process. The electrocapacitive behavior of the resultant composites is systematically investigated by cyclic voltammeter and galvanostatic charge-discharge techniques, where a positive synergistic effect between graphene and Fe3O4 clusters is identified. A maximum specific capacitance of 169 F g-1 is achieved in the Fe3O4 clusters decorated with effectively reduced graphene oxide (Fe3O4-rGO-12h), which is much higher than those of rGO (101 F g-1) and Fe3O4 (68 F g-1) at the current density of 1 Ag-1. Moreover, this intercalated hierarchical nanostructure demonstrates a good capacitance retention, retaining over 88% of the initial capacity after 1000 cycles.

A data-driven approach to estimating the number of clusters in hierarchical clustering [version 1; referees: 2 approved, 1 approved with reservations

Directory of Open Access Journals (Sweden)

Antoine E. Zambelli

2016-12-01

Full Text Available DNA microarray and gene expression problems often require a researcher to perform clustering on their data in a bid to better understand its structure. In cases where the number of clusters is not known, one can resort to hierarchical clustering methods. However, there currently exist very few automated algorithms for determining the true number of clusters in the data. We propose two new methods (mode and maximum difference for estimating the number of clusters in a hierarchical clustering framework to create a fully automated process with no human intervention. These methods are compared to the established elbow and gap statistic algorithms using simulated datasets and the Biobase Gene ExpressionSet. We also explore a data mixing procedure inspired by cross validation techniques. We find that the overall performance of the maximum difference method is comparable or greater to that of the gap statistic in multi-cluster scenarios, and achieves that performance at a fraction of the computational cost. This method also responds well to our mixing procedure, which opens the door to future research. We conclude that both the mode and maximum difference methods warrant further study related to their mixing and cross-validation potential. We particularly recommend the use of the maximum difference method in multi-cluster scenarios given its accuracy and execution times, and present it as an alternative to existing algorithms.

A study of the dynamical state of the hot plasma in galaxy clusters using XMM-Newton data and numerical simulation

International Nuclear Information System (INIS)

Solovyeva, Lilia

2008-01-01

Cluster of galaxies are the largest and youngest objects in the Universe and these objects are very interesting for study the cosmology. In this moment with the capacity of the instruments (XMM-Newton, Chandra) and with numerical simulations it is possible to study the dynamical state of gas in the cluster during their formation. And plus, now, we have the possibility to study the cluster in different wavelengths (optics, radio, X-ray). Our study helps us to understand the physics processes in clusters. In our work we studied the galaxy cluster around the maximum core collapse. We used the X-ray data, how the first indicators of dynamical state of gas. After with the help of numerical simulation and optics data we performed the completed analysis with the proposition of merger scenario possible. We performed the detailed analysis of two clusters (CL0016+16 and A548b), these clusters presents the signature of major merger and also we studied the cluster from numerical simulation (Cluster 6) around the major merger. (author) [fr

Performance of heat engines with non-zero heat capacity

International Nuclear Information System (INIS)

Odes, Ron; Kribus, Abraham

2013-01-01

Highlights: ► Finite heat capacity is a second irreversibility mechanism in addition to thermal resistance. ► Heat capacity introduces thermal transients and reverse heat flow. ► Engine maximum power and efficiency are lower for finite heat capacity. ► Implementing the optimal engine cycle requires active control. - Abstract: The performance of a heat engine is analyzed subject to two types of irreversibility: a non-zero heat capacity, together with the more common finite heat transfer rate between the engine and the external heat reservoirs. The heat capacity represents an engine body that undergoes significant temperature variations during the engine cycle. An option to cut off the heat exchange between the engine and the external surrounding for part of the engine cycle is also explored. A variational approach was taken to find the engine’s internal temperature profile (which defines the internal thermodynamic cycle) that would produce maximum power. The maximum power is shown to be lower than the case of zero heat capacity, due to a loss of heat that is stored in the engine body and then lost, bypassing the thermodynamic cycle. The maximum efficiency and the efficiency at maximum power are also lower than the zero heat capacity case. Similar to the Curzon–Ahlborn analysis, power can be traded for increased efficiency, but for high heat capacity, the range of efficiency that is available for such a trade is diminished. Isolating the engine during part of the cycle reduces maximum power, but the efficiency at maximum power and the maximum efficiency are improved, due to better exploitation of heat stored in the engine body. This might be useful for real engines that are limited by the internal energy change during a single engine cycle or by the operating frequency, leading to a broader power–efficiency curve.

Genetic Diversity and Relationships of Neolamarckia cadamba (Roxb. Bosser progenies through cluster analysis

Directory of Open Access Journals (Sweden)

M. Preethi Shree

2018-04-01

Full Text Available Genetic diversity analysis was conducted for biometric attributes in 20 progenies of Neolamarckia cadamba. The application of D2 clustering technique in Neolamarckia cadamba genetic resources resolved the 20 progenies into five clusters. The maximum intra cluster distance was shown by the cluster II. The maximum inter cluster distance was recorded between cluster III and V which indicated the presence of wider genetic distance between Neolamarckia cadamba progenies. Among the growth attributes, volume (36.84 % contributed maximum towards genetic divergence followed by bole height, basal diameter, tree height, number of branches in Neolamarckia cadamba progenies.

Maximum Acceptable Weight of Lift reflects peak lumbosacral extension moments in a Functional Capacity Evaluation test using free style, stoop, and squat lifting

OpenAIRE

Kuijer, P.P.F.M.; van Oostrom, S.H.; Duijzer, K.; van Dieen, J.H.

2012-01-01

It is unclear whether the maximum acceptable weight of lift (MAWL), a common psychophysical method, reflects joint kinetics when different lifting techniques are employed. In a within-participants study (n = 12), participants performed three lifting techniques - free style, stoop and squat lifting from knee to waist level - using the same dynamic functional capacity evaluation lifting test to assess MAWL and to calculate low back and knee kinetics. We assessed which knee and back kinetic para...

Maximum acceptable weight of lift reflects peak lumbosacral extension moments in a functional capacity evaluation test using free style, stoop and squat lifting.

Science.gov (United States)

Kuijer, P P F M; van Oostrom, S H; Duijzer, K; van Dieën, J H

2012-01-01

It is unclear whether the maximum acceptable weight of lift (MAWL), a common psychophysical method, reflects joint kinetics when different lifting techniques are employed. In a within-participants study (n = 12), participants performed three lifting techniques--free style, stoop and squat lifting from knee to waist level--using the same dynamic functional capacity evaluation lifting test to assess MAWL and to calculate low back and knee kinetics. We assessed which knee and back kinetic parameters increased with the load mass lifted, and whether the magnitudes of the kinetic parameters were consistent across techniques when lifting MAWL. MAWL was significantly different between techniques (p = 0.03). The peak lumbosacral extension moment met both criteria: it had the highest association with the load masses lifted (r > 0.9) and was most consistent between the three techniques when lifting MAWL (ICC = 0.87). In conclusion, MAWL reflects the lumbosacral extension moment across free style, stoop and squat lifting in healthy young males, but the relation between the load mass lifted and lumbosacral extension moment is different between techniques. Tests of maximum acceptable weight of lift (MAWL) from knee to waist height are used to assess work capacity of individuals with low-back disorders. This article shows that the MAWL reflects the lumbosacral extension moment across free style, stoop and squat lifting in healthy young males, but the relation between the load mass lifted and lumbosacral extension moment is different between techniques. This suggests that standardisation of lifting technique used in tests of the MAWL would be indicated if the aim is to assess the capacity of the low back.

An alternative methodological approach to value analysis of regions, municipal corporations and clusters

Directory of Open Access Journals (Sweden)

Mojmír Sabolovič

2011-01-01

Full Text Available The paper deals with theoretical conception of value analysis of regions, municipal corporations and clusters. The subject of this paper is heterodox approach to sensitivity analysis of finite set of variables based on non-additive measure. For dynamic analysis of trajectory of general value are sufficient robust models based on maximum entropy principle. Findings concern explanation of proper fuzzy integral – Choquet integral. The fuzzy measure is represented by theory of capacities (Choquet, 1953 on powerset. In fine, the conception of the New integral for capacities (Lehler, 2005 is discussed. Value analysis and transmission constitutes remarkable aspect of performance evaluation of regions, municipal corporations and clusters. In the light of high ratio of soft variables, social behavior, intangible assets and human capital within those types of subjects the fuzzy integral introduce useful tool for modeling. The New integral afterwards concerns considerable characteristic of people behavior – risk averse articulated concave function and non-additive operator. Results comprehended tools enabling observation of synergy, redundancy and inhibition of value variables as consequence of non-additive measure. In fine, results induced issues for future research.

Using Evaluation for CBNRM Capacity Development (Southeast Asia)

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

Using Evaluation for CBNRM Capacity Development (Southeast Asia) ... for evaluating both the process and outcome of capacity development efforts in CBNRM. ... Cluster Case Studies Planning Workshop, Beijing, September 21-23, 2006; ...

Clustering algorithms for Stokes space modulation format recognition

DEFF Research Database (Denmark)

Boada, Ricard; Borkowski, Robert; Tafur Monroy, Idelfonso

2015-01-01

influences the performance of the detection process, particularly at low signal-to-noise ratios. This paper reports on an extensive study of six different clustering algorithms: k-means, expectation maximization, density-based DBSCAN and OPTICS, spectral clustering and maximum likelihood clustering, used...

33 CFR 183.41 - Persons capacity: Outboard boats.

Science.gov (United States)

2010-07-01

... tank weight from table 4 of subpart H of this part; or (2) For boats with a maximum persons capacity less than 550 pounds, the maximum persons capacity determined in the following manner: (i) Float the... control weight, battery weight, and full portable fuel tank weight, if any, shown in table 4 of subpart H...

Hierarchical Star Formation in Turbulent Media: Evidence from Young Star Clusters

Energy Technology Data Exchange (ETDEWEB)

Grasha, K.; Calzetti, D. [Astronomy Department, University of Massachusetts, Amherst, MA 01003 (United States); Elmegreen, B. G. [IBM Research Division, T.J. Watson Research Center, Yorktown Heights, NY (United States); Adamo, A.; Messa, M. [Department of Astronomy, The Oskar Klein Centre, Stockholm University, Stockholm (Sweden); Aloisi, A.; Bright, S. N.; Lee, J. C.; Ryon, J. E.; Ubeda, L. [Space Telescope Science Institute, Baltimore, MD (United States); Cook, D. O. [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA (United States); Dale, D. A. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY (United States); Fumagalli, M. [Institute for Computational Cosmology and Centre for Extragalactic Astronomy, Department of Physics, Durham University, Durham (United Kingdom); Gallagher III, J. S. [Department of Astronomy, University of Wisconsin–Madison, Madison, WI (United States); Gouliermis, D. A. [Zentrum für Astronomie der Universität Heidelberg, Institut für Theoretische Astrophysik, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Grebel, E. K. [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12-14, D-69120, Heidelberg (Germany); Kahre, L. [Department of Astronomy, New Mexico State University, Las Cruces, NM (United States); Kim, H. [Gemini Observatory, La Serena (Chile); Krumholz, M. R., E-mail: kgrasha@astro.umass.edu [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia)

2017-06-10

We present an analysis of the positions and ages of young star clusters in eight local galaxies to investigate the connection between the age difference and separation of cluster pairs. We find that star clusters do not form uniformly but instead are distributed so that the age difference increases with the cluster pair separation to the 0.25–0.6 power, and that the maximum size over which star formation is physically correlated ranges from ∼200 pc to ∼1 kpc. The observed trends between age difference and separation suggest that cluster formation is hierarchical both in space and time: clusters that are close to each other are more similar in age than clusters born further apart. The temporal correlations between stellar aggregates have slopes that are consistent with predictions of turbulence acting as the primary driver of star formation. The velocity associated with the maximum size is proportional to the galaxy’s shear, suggesting that the galactic environment influences the maximum size of the star-forming structures.

Simulations of floor cooling system capacity

International Nuclear Information System (INIS)

Odyjas, Andrzej; Górka, Andrzej

2013-01-01

Floor cooling system capacity depends on its physical and operative parameters. Using numerical simulations, it appears that cooling capacity of the system largely depends on the type of cooling loads occurring in the room. In the case of convective cooling loads capacity of the system is small. However, when radiation flux falls directly on the floor the system significantly increases productivity. The article describes the results of numerical simulations which allow to determine system capacity in steady thermal conditions, depending on the type of physical parameters of the system and the type of cooling load occurring in the room. Moreover, the paper sets out the limits of system capacity while maintaining a minimum temperature of the floor surface equal to 20 °C. The results are helpful for designing system capacity in different type of cooling loads and show maximum system capacity in acceptable thermal comfort condition. -- Highlights: ► We have developed numerical model for simulation of floor cooling system. ► We have described floor system capacity depending on its physical parameters. ► We have described floor system capacity depending on type of cooling loads. ► The most important in the obtained cooling capacities is the type of cooling loads. ► The paper sets out the possible maximum cooling floor system capacity

Assessment of Maximum Aerobic Capacity and Anaerobic Threshold of Elite Ballet Dancers.

Science.gov (United States)

Wyon, Matthew A; Allen, Nick; Cloak, Ross; Beck, Sarah; Davies, Paul; Clarke, Frances

2016-09-01

An athlete's cardiorespiratory profile, maximal aerobic capacity, and anaerobic threshold is affected by training regimen and competition demands. The present study aimed to ascertain whether there are company rank differences in maximal aerobic capacity and anaerobic threshold in elite classical ballet dancers. Seventy-four volunteers (M 34, F 40) were recruited from two full-time professional classical ballet companies. All participants completed a continuous incremental treadmill protocol with a 1-km/hr speed increase at the end of each 1-min stage until termination criteria had been achieved (e.g., voluntary cessation, respiratory exchange ratio ballet companies are probably due to the different rehearsal and performance demands.

Fitting Latent Cluster Models for Networks with latentnet

Directory of Open Access Journals (Sweden)

Pavel N. Krivitsky

2007-12-01

Full Text Available latentnet is a package to fit and evaluate statistical latent position and cluster models for networks. Hoff, Raftery, and Handcock (2002 suggested an approach to modeling networks based on positing the existence of an latent space of characteristics of the actors. Relationships form as a function of distances between these characteristics as well as functions of observed dyadic level covariates. In latentnet social distances are represented in a Euclidean space. It also includes a variant of the extension of the latent position model to allow for clustering of the positions developed in Handcock, Raftery, and Tantrum (2007.The package implements Bayesian inference for the models based on an Markov chain Monte Carlo algorithm. It can also compute maximum likelihood estimates for the latent position model and a two-stage maximum likelihood method for the latent position cluster model. For latent position cluster models, the package provides a Bayesian way of assessing how many groups there are, and thus whether or not there is any clustering (since if the preferred number of groups is 1, there is little evidence for clustering. It also estimates which cluster each actor belongs to. These estimates are probabilistic, and provide the probability of each actor belonging to each cluster. It computes four types of point estimates for the coefficients and positions: maximum likelihood estimate, posterior mean, posterior mode and the estimator which minimizes Kullback-Leibler divergence from the posterior. You can assess the goodness-of-fit of the model via posterior predictive checks. It has a function to simulate networks from a latent position or latent position cluster model.

Capacity in the energy underwriting market - an overview

International Nuclear Information System (INIS)

Mulhall, L.

1992-01-01

It is important to clarify the different definitions of capacity, and in the insurance business this work has two distinct interpretations. The capacity of a Lloyd's syndicate is described by its ability to write premium income. Of more interest is the maximum ability and willingness of an underwriter, whether Lloyds's or Company, to commit itself to catastrophe loss policies. Or put more simply, what is the size of their line? It is this capacity for covering high value catastrophic exposure or Target Risks that will be discussed using the definition that capacity in this case is: ''The ability of insurance markets to cover any single maximum loss''. (Author)

Effect of a Nutrition Supplement and Physical Activity Program on Pneumonia and Walking Capacity in Chilean Older People: A Factorial Cluster Randomized Trial

Science.gov (United States)

Dangour, Alan D.; Albala, Cecilia; Allen, Elizabeth; Grundy, Emily; Walker, Damian G.; Aedo, Cristian; Sanchez, Hugo; Fletcher, Olivia; Elbourne, Diana; Uauy, Ricardo

2011-01-01

Background Ageing is associated with increased risk of poor health and functional decline. Uncertainties about the health-related benefits of nutrition and physical activity for older people have precluded their widespread implementation. We investigated the effectiveness and cost-effectiveness of a national nutritional supplementation program and/or a physical activity intervention among older people in Chile. Methods and Findings We conducted a cluster randomized factorial trial among low to middle socioeconomic status adults aged 65–67.9 years living in Santiago, Chile. We randomized 28 clusters (health centers) into the study and recruited 2,799 individuals in 2005 (∼100 per cluster). The interventions were a daily micronutrient-rich nutritional supplement, or two 1-hour physical activity classes per week, or both interventions, or neither, for 24 months. The primary outcomes, assessed blind to allocation, were incidence of pneumonia over 24 months, and physical function assessed by walking capacity 24 months after enrolment. Adherence was good for the nutritional supplement (∼75%), and moderate for the physical activity intervention (∼43%). Over 24 months the incidence rate of pneumonia did not differ between intervention and control clusters (32.5 versus 32.6 per 1,000 person years respectively; risk ratio = 1.00; 95% confidence interval 0.61–1.63; p = 0.99). In intention-to-treat analysis, after 24 months there was a significant difference in walking capacity between the intervention and control clusters (mean difference 33.8 meters; 95% confidence interval 13.9–53.8; p = 0.001). The overall cost of the physical activity intervention over 24 months was US$164/participant; equivalent to US$4.84/extra meter walked. The number of falls and fractures was balanced across physical activity intervention arms and no serious adverse events were reported for either intervention. Conclusions Chile's nutritional supplementation program for older

Effect of a nutrition supplement and physical activity program on pneumonia and walking capacity in Chilean older people: a factorial cluster randomized trial.

Directory of Open Access Journals (Sweden)

Alan D Dangour

2011-04-01

Full Text Available Ageing is associated with increased risk of poor health and functional decline. Uncertainties about the health-related benefits of nutrition and physical activity for older people have precluded their widespread implementation. We investigated the effectiveness and cost-effectiveness of a national nutritional supplementation program and/or a physical activity intervention among older people in Chile.We conducted a cluster randomized factorial trial among low to middle socioeconomic status adults aged 65-67.9 years living in Santiago, Chile. We randomized 28 clusters (health centers into the study and recruited 2,799 individuals in 2005 (~100 per cluster. The interventions were a daily micronutrient-rich nutritional supplement, or two 1-hour physical activity classes per week, or both interventions, or neither, for 24 months. The primary outcomes, assessed blind to allocation, were incidence of pneumonia over 24 months, and physical function assessed by walking capacity 24 months after enrollment. Adherence was good for the nutritional supplement (~75%, and moderate for the physical activity intervention (~43%. Over 24 months the incidence rate of pneumonia did not differ between intervention and control clusters (32.5 versus 32.6 per 1,000 person years respectively; risk ratio = 1.00; 95% confidence interval 0.61-1.63; p = 0.99. In intention-to-treat analysis, after 24 months there was a significant difference in walking capacity between the intervention and control clusters (mean difference 33.8 meters; 95% confidence interval 13.9-53.8; p = 0.001. The overall cost of the physical activity intervention over 24 months was US$164/participant; equivalent to US$4.84/extra meter walked. The number of falls and fractures was balanced across physical activity intervention arms and no serious adverse events were reported for either intervention.Chile's nutritional supplementation program for older people is not effective in reducing the

Cluster infall in the concordance LCDM model

OpenAIRE

Pivato, Maximiliano C.; Padilla, Nelson D.; Lambas, Diego G.

2005-01-01

We perform statistical analyses of the infall of dark-matter onto clusters in numerical simulations within the concordance LCDM model. By studying the infall profile around clusters of different mass, we find a linear relation between the maximum infall velocity and mass which reach 900km/s for the most massive groups. The maximum infall velocity and the group mass follow a suitable power law fit of the form, V_{inf}^{max} = (M/m_0)^{gamma}. By comparing the measured infall velocity to the li...

Estimation of Maximum Allowable PV Connection to LV Residential Power Networks

DEFF Research Database (Denmark)

Demirok, Erhan; Sera, Dezso; Teodorescu, Remus

2011-01-01

Maximum photovoltaic (PV) hosting capacity of low voltage (LV) power networks is mainly restricted by either thermal limits of network components or grid voltage quality resulted from high penetration of distributed PV systems. This maximum hosting capacity may be lower than the available solar...... potential of geographic area due to power network limitations even though all rooftops are fully occupied with PV modules. Therefore, it becomes more of an issue to know what exactly limits higher PV penetration level and which solutions should be engaged efficiently such as over sizing distribution...

Defining clusters in APT reconstructions of ODS steels.

Science.gov (United States)

Williams, Ceri A; Haley, Daniel; Marquis, Emmanuelle A; Smith, George D W; Moody, Michael P

2013-09-01

Oxide nanoclusters in a consolidated Fe-14Cr-2W-0.3Ti-0.3Y₂O₃ ODS steel and in the alloy powder after mechanical alloying (but before consolidation) are investigated by atom probe tomography (APT). The maximum separation method is a standard method to define and characterise clusters from within APT data, but this work shows that the extent of clustering between the two materials is sufficiently different that the nanoclusters in the mechanically alloyed powder and in the consolidated material cannot be compared directly using the same cluster selection parameters. As the cluster selection parameters influence the size and composition of the clusters significantly, a procedure to optimise the input parameters for the maximum separation method is proposed by sweeping the d(max) and N(min) parameter space. By applying this method of cluster parameter selection combined with a 'matrix correction' to account for trajectory aberrations, differences in the oxide nanoclusters can then be reliably quantified. Copyright © 2012 Elsevier B.V. All rights reserved.

Connectivity strategies to enhance the capacity of weight-bearing networks

International Nuclear Information System (INIS)

Janaki, T.M.; Gupte, Neelima

2003-01-01

The connectivity properties of a weight-bearing network are exploited to enhance its capacity. We study a 2D network of sites where the weight-bearing capacity of a given site depends on the capacities of the sites connected to it in the layers above. The network consists of clusters, viz., a set of sites connected with each other with the largest such collection of sites being denoted as the maximal cluster. New connections are made between sites in successive layers using two distinct strategies. The key element of our strategies consists of adding as many disjoint clusters as possible to the sites on the trunk T of the maximal cluster. In the first strategy the reconnections start from the last layer upwards and stop when no new sites are added. In the second case, the reconnections start from the top layer and go all the way down to the last layer. The new networks can bear much higher weights than the original networks and have much lower failure rates. The first strategy leads to a greater enhancement of stability, whereas the second leads to a greater enhancement of capacity compared to the original networks. The original network used here is a typical example of the branching hierarchical class. However, the application of strategies similar to ours can yield useful results in other types of networks as well

Maximum Likelihood Blind Channel Estimation for Space-Time Coding Systems

Directory of Open Access Journals (Sweden)

Hakan A. Çırpan

2002-05-01

Full Text Available Sophisticated signal processing techniques have to be developed for capacity enhancement of future wireless communication systems. In recent years, space-time coding is proposed to provide significant capacity gains over the traditional communication systems in fading wireless channels. Space-time codes are obtained by combining channel coding, modulation, transmit diversity, and optional receive diversity in order to provide diversity at the receiver and coding gain without sacrificing the bandwidth. In this paper, we consider the problem of blind estimation of space-time coded signals along with the channel parameters. Both conditional and unconditional maximum likelihood approaches are developed and iterative solutions are proposed. The conditional maximum likelihood algorithm is based on iterative least squares with projection whereas the unconditional maximum likelihood approach is developed by means of finite state Markov process modelling. The performance analysis issues of the proposed methods are studied. Finally, some simulation results are presented.

Cluster Analysis of Maize Inbred Lines

Directory of Open Access Journals (Sweden)

Jiban Shrestha

2016-12-01

Full Text Available The determination of diversity among inbred lines is important for heterosis breeding. Sixty maize inbred lines were evaluated for their eight agro morphological traits during winter season of 2011 to analyze their genetic diversity. Clustering was done by average linkage method. The inbred lines were grouped into six clusters. Inbred lines grouped into Clusters II had taller plants with maximum number of leaves. The cluster III was characterized with shorter plants with minimum number of leaves. The inbred lines categorized into cluster V had early flowering whereas the group into cluster VI had late flowering time. The inbred lines grouped into the cluster III were characterized by higher value of anthesis silking interval (ASI and those of cluster VI had lower value of ASI. These results showed that the inbred lines having widely divergent clusters can be utilized in hybrid breeding programme.

Simple product-form bounds for queueing networks with finite clusters

NARCIS (Netherlands)

van Dijk, N.M.; van der Sluis, E.

2001-01-01

Queueing networks are studied with finite capacity constraints for clusters of stations. First, by an instructive tandem cluster example it is shown how a product-form modification method for networks with finite stations can be extended to networks with finite clusters. Next, a general result is

Dynamical resonance shift and unification of resonances in short-pulse laser-cluster interaction

Science.gov (United States)

Mahalik, S. S.; Kundu, M.

2018-06-01

Pronounced maximum absorption of laser light irradiating a rare-gas or metal cluster is widely expected during the linear resonance (LR) when Mie-plasma wavelength λM of electrons equals the laser wavelength λ . On the contrary, by performing molecular dynamics (MD) simulations of an argon cluster irradiated by short 5-fs (FWHM) laser pulses it is revealed that, for a given laser pulse energy and a cluster, at each peak intensity there exists a λ —shifted from the expected λM—that corresponds to a unified dynamical LR at which evolution of the cluster happens through very efficient unification of possible resonances in various stages, including (i) the LR in the initial time of plasma creation, (ii) the LR in the Coulomb expanding phase in the later time, and (iii) anharmonic resonance in the marginally overdense regime for a relatively longer pulse duration, leading to maximum laser absorption accompanied by maximum removal of electrons from cluster and also maximum allowed average charge states for the argon cluster. Increasing the laser intensity, the absorption maxima is found to shift to a higher wavelength in the band of λ ≈(1 -1.5 ) λM than permanently staying at the expected λM. A naive rigid sphere model also corroborates the wavelength shift of the absorption peak as found in MD and unequivocally proves that maximum laser absorption in a cluster happens at a shifted λ in the marginally overdense regime of λ ≈(1 -1.5 ) λM instead of λM of LR. The present study is important for guiding an optimal condition laser-cluster interaction experiment in the short-pulse regime.

Capacity limits introduced by data fusion on cooperative spectrum sensing under correlated environments

DEFF Research Database (Denmark)

Pratas, Nuno; Marchetti, Nicola; Rodrigues, Antonio

2010-01-01

spectrum sensing scheme, by measuring the perceived capacity limits introduced by the use of data fusion on cooperative sensing schemes. The analysis is supported by evaluation metrics which account for the perceived capacity limits. The analysis is performed along the data fusion chain, comparing several...... scenarios encompassing different degree of environment correlation between the cluster nodes, number of cluster nodes and sensed channel occupation statistics. Through this study we motivate that to maximize the perceived capacity by the cooperative spectrum sensing, the use of data fusion needs...

MEASUREMENT OF SPECIFIC HEAT CAPACITY OF SALTSTONE

International Nuclear Information System (INIS)

Harbour, J.; Williams, V.

2008-01-01

One of the goals of the Saltstone variability study is to identify (and quantify the impact of) the operational and compositional variables that control or influence the important processing and performance properties of Saltstone grout mixtures. The heat capacity of the Saltstone waste form is one of the important properties of Saltstone mixes that was last measured at SRNL in 1997. It is therefore important to develop a core competency for rapid and accurate analysis of the specific heat capacity of the Saltstone mixes in order to quantify the impact of compositional and operational variations on this property as part of the variability study. The heat capacity, coupled with the heat of hydration data obtained from isothermal calorimetry for a given Saltstone mix, can be used to predict the maximum temperature increase in the cells within the vaults of the Saltstone Disposal Facility (SDF). The temperature increase controls the processing rate and the pour schedule. The maximum temperature is also important to the performance properties of the Saltstone. For example, in mass pours of concrete or grout of which Saltstone is an example, the maximum temperature increase and the maximum temperature difference (between the surface and the hottest location) are controlled to ensure durability of the product and prevent or limit the cracking caused by the thermal gradients produced during curing. This report details the development and implementation of a method for the measurement of the heat capacities of Saltstone mixes as well as the heat capacities of the cementitious materials of the premix and the simulated salt solutions used to batch the mixes. The developed method utilizes the TAM Air isothermal calorimeter and takes advantage of the sophisticated heat flow measurement capabilities of the instrument. Standards and reference materials were identified and used to validate the procedure and ensure accuracy of testing. Heat capacities of Saltstone mixes were �

MEASUREMENT OF SPECIFIC HEAT CAPACITY OF SALTSTONE

Energy Technology Data Exchange (ETDEWEB)

Harbour, J; Vickie Williams, V

2008-09-29

One of the goals of the Saltstone variability study is to identify (and quantify the impact of) the operational and compositional variables that control or influence the important processing and performance properties of Saltstone grout mixtures. The heat capacity of the Saltstone waste form is one of the important properties of Saltstone mixes that was last measured at SRNL in 1997. It is therefore important to develop a core competency for rapid and accurate analysis of the specific heat capacity of the Saltstone mixes in order to quantify the impact of compositional and operational variations on this property as part of the variability study. The heat capacity, coupled with the heat of hydration data obtained from isothermal calorimetry for a given Saltstone mix, can be used to predict the maximum temperature increase in the cells within the vaults of the Saltstone Disposal Facility (SDF). The temperature increase controls the processing rate and the pour schedule. The maximum temperature is also important to the performance properties of the Saltstone. For example, in mass pours of concrete or grout of which Saltstone is an example, the maximum temperature increase and the maximum temperature difference (between the surface and the hottest location) are controlled to ensure durability of the product and prevent or limit the cracking caused by the thermal gradients produced during curing. This report details the development and implementation of a method for the measurement of the heat capacities of Saltstone mixes as well as the heat capacities of the cementitious materials of the premix and the simulated salt solutions used to batch the mixes. The developed method utilizes the TAM Air isothermal calorimeter and takes advantage of the sophisticated heat flow measurement capabilities of the instrument. Standards and reference materials were identified and used to validate the procedure and ensure accuracy of testing. Heat capacities of Saltstone mixes were

'MATRI-SUMAN' a capacity building and text messaging intervention to enhance maternal and child health service utilization among pregnant women from rural Nepal: study protocol for a cluster randomised controlled trial.

Science.gov (United States)

Singh, Jitendra Kumar; Kadel, Rajendra; Acharya, Dilaram; Lombard, Daniel; Khanal, Saval; Singh, Shri Prakash

2018-06-14

Capacity development of health volunteers and text messaging to pregnant women through mobile phones have shown improved maternal and child health (MCH) outcomes and is associated with increased utilisation of MCH services. However, such interventions are uncommon in Nepal. We aim to carry out an intervention with the hypothesis that capacity building and text messaging intervention will increase the MCH service utilisation. MATRI-SUMAN is a 12-month cluster randomized controlled trial (RCT). The trial involves pregnant women from 52 clusters of six village development committees (VDCs) covering 66,000 populations of Dhanusha district of Nepal. In the intervention clusters, Female Community Health Volunteers (FCHVs) will receive capacity development skills through reinforcement training, supervision and monitoring skills for the promotion of health seeking behaviour among pregnant women and study participants will receive periodic promotional text messaging service about MCH components through mobile phones. A sample of 354with equal numbers in each study arm is estimated using power calculation formula. The primary outcomes of this study are the rate of utilization of skilled birth attendants and consumption of a specified diversified meal. The secondary outcomes are: four antenatal (ANC) visits, weight gain of women during pregnancy, delivery of a baby at the health facility, postnatal care (PNC) visits, positive changes in child feeding practices among mothers, performance of FCHVs in MCH service utilization. The intervention is designed to enhance the capacity of health volunteers for the promotion of health seeking behaviour among pregnant women and text messaging through a mobile phone to expecting mothers to increase MCH service utilization. The trial if proven effective will have policy implications in poor resource settings. ISRCTN60684155, ( https://doi.org/10.1186/ISRCTN60684155 ). The trial was registered retrospectively.

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/.

A polynomial time algorithm for solving the maximum flow problem in directed networks

International Nuclear Information System (INIS)

Tlas, M.

2015-01-01

An efficient polynomial time algorithm for solving maximum flow problems has been proposed in this paper. The algorithm is basically based on the binary representation of capacities; it solves the maximum flow problem as a sequence of O(m) shortest path problems on residual networks with nodes and m arcs. It runs in O(m"2r) time, where is the smallest integer greater than or equal to log B , and B is the largest arc capacity of the network. A numerical example has been illustrated using this proposed algorithm.(author)

Liquid films on shake flask walls explain increasing maximum oxygen transfer capacities with elevating viscosity.

Science.gov (United States)

Giese, Heiner; Azizan, Amizon; Kümmel, Anne; Liao, Anping; Peter, Cyril P; Fonseca, João A; Hermann, Robert; Duarte, Tiago M; Büchs, Jochen

2014-02-01

In biotechnological screening and production, oxygen supply is a crucial parameter. Even though oxygen transfer is well documented for viscous cultivations in stirred tanks, little is known about the gas/liquid oxygen transfer in shake flask cultures that become increasingly viscous during cultivation. Especially the oxygen transfer into the liquid film, adhering on the shake flask wall, has not yet been described for such cultivations. In this study, the oxygen transfer of chemical and microbial model experiments was measured and the suitability of the widely applied film theory of Higbie was studied. With numerical simulations of Fick's law of diffusion, it was demonstrated that Higbie's film theory does not apply for cultivations which occur at viscosities up to 10 mPa s. For the first time, it was experimentally shown that the maximum oxygen transfer capacity OTRmax increases in shake flasks when viscosity is increased from 1 to 10 mPa s, leading to an improved oxygen supply for microorganisms. Additionally, the OTRmax does not significantly undermatch the OTRmax at waterlike viscosities, even at elevated viscosities of up to 80 mPa s. In this range, a shake flask is a somehow self-regulating system with respect to oxygen supply. This is in contrary to stirred tanks, where the oxygen supply is steadily reduced to only 5% at 80 mPa s. Since, the liquid film formation at shake flask walls inherently promotes the oxygen supply at moderate and at elevated viscosities, these results have significant implications for scale-up. © 2013 Wiley Periodicals, Inc.

Binary model for the coma cluster of galaxies

International Nuclear Information System (INIS)

Valtonen, M.J.; Byrd, G.G.

1979-01-01

We study the dynamics of galaxies in the Coma cluster and find that the cluster is probably dominated by a central binary of galaxies NGC 4874--NGC4889. We estimate their total mass to be about 3 x 10 14 M/sub sun/ by two independent methods (assuming in Hubble constant of 100 km s -1 Mpc -1 ). This binary is efficient in dynamically ejecting smaller galaxies, some of of which are seen in projection against the inner 3 0 radius of the cluster and which, if erroneously considered as bound members, cause a serious overestimate of the mass of the entire cluster. Taking account of the ejected galaxies, we estimate the total cluster mass to be 4--9 x 10 14 M/sub sun/, with a corresponding mass-to-light ratio for a typical galaxy in the range of 20--120 solar units. The origin of the secondary maximum observed in the radial surface density profile is studied. We consider it to be a remnant of a shell of galaxies which formed around the central binary. This shell expanded, then collapsed into the binary, and is now reexpanding. This is supported by the coincidence of the minimum in the cluster eccentricity and radical velocity dispersion at the same radial distance as the secondary maximum. Numerical simulations of a cluster model with a massive central binary and a spherical shell of test particles are performed, and they reproduce the observed shape, galaxy density, and radial velocity distributions in the Coma cluster fairly well. Consequences of extending the model to other clusters are discussed

Capacity factors of a mixed speed railway network

DEFF Research Database (Denmark)

Harrod, Steven

2009-01-01

Fifty-four combinations of track network and speed differential are evaluated within a linear, discrete time network model that maximizes an objective function of train volume, delays, and idle train time. The results contradict accepted dispatching practice by suggesting that when introducing...... a priority, high-speed train onto a network, maximum network now is attained when the priority train operates at maximum speed. in addition, increasing siding capacity at meeting points may offer a network capacity improvement comparable to partial double track. (C) 2009 Elsevier Ltd. All rights reserved....

Eigenstructures of MIMO Fading Channel Correlation Matrices and Optimum Linear Precoding Designs for Maximum Ergodic Capacity

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Hamid Reza Bahrami

2007-01-01

Full Text Available The ergodic capacity of MIMO frequency-flat and -selective channels depends greatly on the eigenvalue distribution of spatial correlation matrices. Knowing the eigenstructure of correlation matrices at the transmitter is very important to enhance the capacity of the system. This fact becomes of great importance in MIMO wireless systems where because of the fast changing nature of the underlying channel, full channel knowledge is difficult to obtain at the transmitter. In this paper, we first investigate the effect of eigenvalues distribution of spatial correlation matrices on the capacity of frequency-flat and -selective channels. Next, we introduce a practical scheme known as linear precoding that can enhance the ergodic capacity of the channel by changing the eigenstructure of the channel by applying a linear transformation. We derive the structures of precoders using eigenvalue decomposition and linear algebra techniques in both cases and show their similarities from an algebraic point of view. Simulations show the ability of this technique to change the eigenstructure of the channel, and hence enhance the ergodic capacity considerably.

Enriching the hydrogen storage capacity of carbon nanotube doped with polylithiated molecules

Science.gov (United States)

Panigrahi, P.; Naqvi, S. R.; Hankel, M.; Ahuja, R.; Hussain, T.

2018-06-01

In a quest to find optimum materials for efficient storage of clean energy, we have performed first principles calculations to study the structural and energy storage properties of one-dimensional carbon nanotubes (CNTs) functionalized with polylithiated molecules (PLMs). Van der Waals corrected calculations disclosed that various PLMs like CLi, CLi2, CLi3, OLi, OLi2, OLi3, bind strongly to CNTs even at high doping concentrations ensuring a uniform distribution of dopants without forming clusters. Bader charge analysis reveals that each Li in all the PLMs attains a partial positive charge and transform into Li+ cations. This situation allows multiple H2 molecules adsorbed with each Li+ through the polarization of incident H2 molecules via electrostatic and van der Waals type of interaction. With a maximum doping concentration, that is 3CLi2/3CLi3 and 3OLi2/3OLi3 a maximum of 36 H2 molecules could be adsorbed that corresponds to a reasonably high H2 storage capacity with the adsorption energies in the range of -0.33 to -0.15 eV/H2. This suits the ambient condition applications.

49 CFR 237.71 - Determination of bridge load capacities.

Science.gov (United States)

2010-10-01

... capacity shall be determined. (g) Bridge load capacity may be expressed in terms of numerical values related to a standard system of bridge loads, but shall in any case be stated in terms of weight and...) Bridge load capacity may be expressed in terms of both normal and maximum load conditions. Operation of...

Urban development control based on transportation carrying capacity

Science.gov (United States)

Miharja, M.; Sjafruddin, A. H.

2017-06-01

Severe transportation problems in Indonesian urban areas are stimulated by one fundamental factor, namely lack of awareness on transportation carrying capacity in these areas development control. Urban land use development towards more physical coverage is typically not related with the capability of transportation system to accommodate additional trips volume. Lack of clear connection between development permit with its implication on the transportation side has led to a phenomenon of exceeding transport demand over supply capacity. This paper discusses the concept of urban land use development control which will be related with transport carrying capacity. The discussion would cover both supply and demand sides of transportation. From supply side, the analysis regarding the capacity of transport system would take both existing as well as potential road network capacity could be developed. From demand side, the analysis would be through the control of a maximum floor area and public transport provision. Allowed maximum floor area for development would be at the level of generating traffic at reasonable volume. Ultimately, the objective of this paper is to introduce model to incorporate transport carrying capacity in Indonesian urban land use development control.

Clustering recommendations to compute agent reputation

Science.gov (United States)

Bedi, Punam; Kaur, Harmeet

2005-03-01

Traditional centralized approaches to security are difficult to apply to multi-agent systems which are used nowadays in e-commerce applications. Developing a notion of trust that is based on the reputation of an agent can provide a softer notion of security that is sufficient for many multi-agent applications. Our paper proposes a mechanism for computing reputation of the trustee agent for use by the trustier agent. The trustier agent computes the reputation based on its own experience as well as the experience the peer agents have with the trustee agents. The trustier agents intentionally interact with the peer agents to get their experience information in the form of recommendations. We have also considered the case of unintentional encounters between the referee agents and the trustee agent, which can be directly between them or indirectly through a set of interacting agents. The clustering is done to filter off the noise in the recommendations in the form of outliers. The trustier agent clusters the recommendations received from referee agents on the basis of the distances between recommendations using the hierarchical agglomerative method. The dendogram hence obtained is cut at the required similarity level which restricts the maximum distance between any two recommendations within a cluster. The cluster with maximum number of elements denotes the views of the majority of recommenders. The center of this cluster represents the reputation of the trustee agent which can be computed using c-means algorithm.

The self limiting effect of hydrogen cluster in gas jet under liquid nitrogen temperature

International Nuclear Information System (INIS)

Han Jifeng; Yang Chaowen; Miao Jingwei; Fu Pengtao; Luo Xiaobing; Shi Miangong

2010-01-01

The generation of hydrogen clusters in gas jet is tested using the Rayleigh scattering method under liquid nitrogen temperature of 79 K. The self limiting effect of hydrogen cluster is studied and it is found that the cluster formation is greatly affected by the number of expanded molecules. The well designed liquid nitrogen cold trap ensured that the hydrogen cluster would keep maximum size for maximum 15 ms during one gas jet. The scattered light intensity exhibits a power scaling on the backing pressure ranging from 5 to 48 bar with the power value of 4.1.

Significance of flow clustering and sequencing on sediment transport: 1D sediment transport modelling

Science.gov (United States)

Hassan, Kazi; Allen, Deonie; Haynes, Heather

2016-04-01

This paper considers 1D hydraulic model data on the effect of high flow clusters and sequencing on sediment transport. Using observed flow gauge data from the River Caldew, England, a novel stochastic modelling approach was developed in order to create alternative 50 year flow sequences. Whilst the observed probability density of gauge data was preserved in all sequences, the order in which those flows occurred was varied using the output from a Hidden Markov Model (HMM) with generalised Pareto distribution (GP). In total, one hundred 50 year synthetic flow series were generated and used as the inflow boundary conditions for individual flow series model runs using the 1D sediment transport model HEC-RAS. The model routed graded sediment through the case study river reach to define the long-term morphological changes. Comparison of individual simulations provided a detailed understanding of the sensitivity of channel capacity to flow sequence. Specifically, each 50 year synthetic flow sequence was analysed using a 3-month, 6-month or 12-month rolling window approach and classified for clusters in peak discharge. As a cluster is described as a temporal grouping of flow events above a specified threshold, the threshold condition used herein is considered as a morphologically active channel forming discharge event. Thus, clusters were identified for peak discharges in excess of 10%, 20%, 50%, 100% and 150% of the 1 year Return Period (RP) event. The window of above-peak flows also required cluster definition and was tested for timeframes 1, 2, 10 and 30 days. Subsequently, clusters could be described in terms of the number of events, maximum peak flow discharge, cumulative flow discharge and skewness (i.e. a description of the flow sequence). The model output for each cluster was analysed for the cumulative flow volume and cumulative sediment transport (mass). This was then compared to the total sediment transport of a single flow event of equivalent flow volume

Mathematical description and program documentation for CLASSY, an adaptive maximum likelihood clustering method

Science.gov (United States)

Lennington, R. K.; Rassbach, M. E.

1979-01-01

Discussed in this report is the clustering algorithm CLASSY, including detailed descriptions of its general structure and mathematical background and of the various major subroutines. The report provides a development of the logic and equations used with specific reference to program variables. Some comments on timing and proposed optimization techniques are included.

Balanced score card for cluster of building materials scrap recycling in Voronezh

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Potekhi Igor

2018-01-01

Full Text Available In this article is described an effort to develop a new system of management and economy of building materials scrap recycling cluster. For this task is used conception “Management by Objective” by American legend Peter Drucker. Thus cluster participants have divergent purposes, but have common purpose, the present conception match the most for develop business strategy of uniting companies in this cluster. As result, it was developed a “Balanced Scorecard” for the cluster. This “Balanced Scorecard” take into account technological features of companies in cluster and developed common purpose system. In base of system structure of indicators there is exist model of cluster. This model can show capacity, output flows and throughput capacity of participants. During develop a system of cluster’s purposes it were learned priorities balance of economy efficiency and natural resource management. There are shown calculation of costs of reuse building recycled materials, located on solid waste landfill. Developed strategic system of purpose of cluster activity allows to get economical benefit all participants and for citizens to save environment from nature disaster.

Cluster headache - clinical pattern and a new severity scale in a Swedish cohort.

Science.gov (United States)

Steinberg, Anna; Fourier, Carmen; Ran, Caroline; Waldenlind, Elisabet; Sjöstrand, Christina; Belin, Andrea Carmine

2018-06-01

Background The aim of this study was to investigate clinical features of a cluster headache cohort in Sweden and to construct and test a new scale for grading severity. Methods Subjects were identified by screening medical records for the ICD 10 code G44.0, that is, cluster headache. Five hundred participating research subjects filled in a questionnaire including personal, demographic and medical aspects. We constructed a novel scale for grading cluster headache in this cohort: The Cluster Headache Severity Scale, which included number of attacks per day, attack and period duration. The lowest total score was three and the highest 12, and we used the Cluster Headache Severity Scale to grade subjects suffering from cluster headache. We further implemented the scale by defining a cluster headache maximum severity subgroup with a high Cluster Headache Severity Scale score ≥ 9. Results A majority (66.7%) of the patients reported that attacks appear at certain time intervals. In addition, cluster headache patients who were current tobacco users or had a history of tobacco consumption had a later age of disease onset (31.7 years) compared to non-tobacco users (28.5 years). The Cluster Headache Severity Scale score was higher in the patient group reporting sporadic or no alcohol intake than in the groups reporting an alcohol consumption of three to four standard units per week or more. Maximum severity cluster headache patients were characterised by higher age at disease onset, greater use of prophylactic medication, reduced hours of sleep, and lower alcohol consumption compared to the non-cluster headache maximum severity group. Conclusion There was a wide variation of severity grade among cluster headache patients, with a very marked impact on daily living for the most profoundly affected.

Melting of size-selected gallium clusters with 60-183 atoms.

Science.gov (United States)

Pyfer, Katheryne L; Kafader, Jared O; Yalamanchali, Anirudh; Jarrold, Martin F

2014-07-10

Heat capacities have been measured as a function of temperature for size-selected gallium cluster cations with between 60 and 183 atoms. Almost all clusters studied show a single peak in the heat capacity that is attributed to a melting transition. The peaks can be fit by a two-state model incorporating only fully solid-like and fully liquid-like species, and hence no partially melted intermediates. The exceptions are Ga90(+), which does not show a peak, and Ga80(+) and Ga81(+), which show two peaks. For the clusters with two peaks, the lower temperature peak is attributed to a structural transition. The melting temperatures for clusters with less than 50 atoms have previously been shown to be hundreds of degrees above the bulk melting point. For clusters with more than 60 atoms the melting temperatures decrease, approaching the bulk value (303 K) at around 95 atoms, and then show several small upward excursions with increasing cluster size. A plot of the latent heat against the entropy change for melting reveals two groups of clusters: the latent heats and entropy changes for clusters with less than 94 atoms are distinct from those for clusters with more than 93 atoms. This observation suggests that a significant change in the nature of the bonding or the structure of the clusters occurs at 93-94 atoms. Even though the melting temperatures are close to the bulk value for the larger clusters studied here, the latent heats and entropies of melting are still far from the bulk values.

PERHITUNGAN IDLE CAPACITY DENGAN MENGGUNAKAN CAM-I CAPACITY MODEL DALAM RANGKA EFISIENSI BIAYA PADA PT X

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Muammar Aditya

2015-09-01

Full Text Available Aim for this research are to analyze capacity cost which incure from company production machines and human resources whose operate the production machine using CAM-I capacity model. CAM-I capacity model is an approach which focus  upon how to manage company resources. This research initiated at PT X which focus to production activity that used small mixer machine, extruder machine, oven drying machine, enrober machine, pan coting machine which consist of hot and cold pan coating machine, and packing machine which consist of vertical packing machine and horizontal packing machine as well as human resources that operates those machine. This research focus on rate capacity, productive capacity, idle capacity, and nonproductive capacity to measure capacity cost. Result of this research shows most of the capacity owned by either by production machine or human resources are not utilized to its maximum potential. There are need to reduce capacity cost owned by production machine and human resoures to increase the product sales but if its unachieveable there will be need to increase efficiency from production machine and human resources by reducing their quantityDOI: 10.15408/ess.v4i1.1961

The Effects of Topology on Throughput Capacity of Large Scale Wireless Networks

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Qiuming Liu

2017-03-01

Full Text Available In this paper, we jointly consider the inhomogeneity and spatial dimension in large scale wireless networks. We study the effects of topology on the throughput capacity. This problem is inherently difficult since it is complex to handle the interference caused by simultaneous transmission. To solve this problem, we, according to the inhomogeneity of topology, divide the transmission into intra-cluster transmission and inter-cluster transmission. For the intra-cluster transmission, a spheroidal percolation model is constructed. The spheroidal percolation model guarantees a constant rate when a power control strategy is adopted. We also propose a cube percolation mode for the inter-cluster transmission. Different from the spheroidal percolation model, a constant transmission rate can be achieved without power control. For both transmissions, we propose a routing scheme with five phases. By comparing the achievable rate of each phase, we get the rate bottleneck, which is the throughput capacity of the network.

Identifying Clusters with Mixture Models that Include Radial Velocity Observations

Science.gov (United States)

Czarnatowicz, Alexis; Ybarra, Jason E.

2018-01-01

The study of stellar clusters plays an integral role in the study of star formation. We present a cluster mixture model that considers radial velocity data in addition to spatial data. Maximum likelihood estimation through the Expectation-Maximization (EM) algorithm is used for parameter estimation. Our mixture model analysis can be used to distinguish adjacent or overlapping clusters, and estimate properties for each cluster.Work supported by awards from the Virginia Foundation for Independent Colleges (VFIC) Undergraduate Science Research Fellowship and The Research Experience @Bridgewater (TREB).

Heat capacity and solid solubility of iron in scandium

International Nuclear Information System (INIS)

Tsang, T.-W.E.

1981-01-01

The maximum solid solubility of iron in scandium was determined to be between 50 and 85 at.ppm in the as-cast condition. As the concentration of iron increases, it segregates along the grain boundary, as is evident from optical metallography and electron microprobe examinations. Annealing also causes the iron dissolved in scandium to separate out and cluster along the grain boundary. Heat capacity measurements show an anomaly in the C/T versus T 2 plots for iron concentrations of 19 at.ppm or greater. For iron dissolved in solid scandium the excess entropy due to the iron impurity is in agreement with the theoretical prediction of ck ln(2S + 1) for an impurity-conduction electron (Kondo) interaction, but is 4 - 8 times larger than the theoretical prediction when iron segregates along the grain boundary. Furthermore, our results suggest that most of the previously reported low temperature physical properties of scandium are probably in error because of either iron impurity-conduction electron interactions or Fe-Fe interactions in the precipitated second-phase Sc-Fe compound. (Auth.)

Novel radial vanadium pentoxide nanobelt clusters for Li-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Liu, Yanping; Zhong, Wenwu [Department of Physics and Electronic Engineering, Taizhou University, Taizhou, Zhejiang 318000 (China); Du, Yinxiao, E-mail: duyinxiao@zzia.edu.cn [Department of Mathematics and Physics, Zhengzhou Institute of Aeronautical Industry Management, Zhengzhou 450015 (China); Yuan, Q.X. [Department of Mathematics and Physics, Zhengzhou Institute of Aeronautical Industry Management, Zhengzhou 450015 (China); Wang, Xu [School of Microelectronics, Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, Xidian University, Xi' an 710071 (China); Jia, Renxu, E-mail: rxjia@mail.xidian.edu.cn [School of Microelectronics, Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, Xidian University, Xi' an 710071 (China)

2015-06-05

Highlights: • Radial V{sub 2}O{sub 5} nanobelt clusters were synthesized by a novel hydrothermal process. • The V{sub 2}O{sub 5} clusters are single crystallites with [0 1 0] growth direction. • Specific discharge capacity of V{sub 2}O{sub 5} is 134 mA h/g coupled with good cycle stability. - Abstract: This paper reports the synthesis, characterization and Li-ion intercalation properties of moundlily-like radial vanadium pentoxide (V{sub 2}O{sub 5}) nanobelt clusters. The V{sub 2}O{sub 5} nanobelt clusters was successfully synthesized by a novel soft template assisted hydrothermal process followed by thermal annealing. The as-prepared products were characterized by X-ray diffraction, thermogravimetric analysis, FT-IR spectrometry, scanning electron microscopy and high resolution transmission electron microscopy. The obtained V{sub 2}O{sub 5} possesses a single-crystalline structure with a preferred orientation along the [0 1 0] crystal plane. Electrochemical analysis shows that the specific discharge capacity of the V{sub 2}O{sub 5} nanobelt clusters reaches 134 mA h/g at a current density of 2 A/g coupled with good cycle stability.

Probing dark energy via galaxy cluster outskirts

Science.gov (United States)

Morandi, Andrea; Sun, Ming

2016-04-01

We present a Bayesian approach to combine Planck data and the X-ray physical properties of the intracluster medium in the virialization region of a sample of 320 galaxy clusters (0.056 definition of cluster boundary radius is more tenable, namely based on a fixed overdensity with respect to the critical density of the Universe. This novel cosmological test has the capacity to provide a generational leap forward in our understanding of the equation of state of dark energy.

Light dependence of carboxylation capacity for C3 photosynthesis models

Science.gov (United States)

Photosynthesis at high light is often modelled by assuming limitation by the maximum capacity of Rubisco carboxylation at low carbon dioxide concentrations, by electron transport capacity at higher concentrations, and sometimes by triose-phosphate utilization rate at the highest concentrations. Pho...

Evaluating Maximum Photovoltaic Integration in District Distribution Systems Considering Optimal Inverter Dispatch and Cloud Shading Conditions

DEFF Research Database (Denmark)

Ding, Tao; Kou, Yu; Yang, Yongheng

2017-01-01

. However, the intermittency of solar PV energy (e.g., due to passing clouds) may affect the PV generation in the district distribution network. To address this issue, the voltage magnitude constraints under the cloud shading conditions should be taken into account in the optimization model, which can......As photovoltaic (PV) integration increases in distribution systems, to investigate the maximum allowable PV integration capacity for a district distribution system becomes necessary in the planning phase, an optimization model is thus proposed to evaluate the maximum PV integration capacity while...

From antinode clusters to node clusters: the concentration-dependent transition of floaters on a standing Faraday wave.

Science.gov (United States)

Sanlı, Ceyda; Lohse, Detlef; van der Meer, Devaraj

2014-05-01

A hydrophilic floating sphere that is denser than water drifts to an amplitude maximum (antinode) of a surface standing wave. A few identical floaters therefore organize into antinode clusters. However, beyond a transitional value of the floater concentration ϕ, we observe that the same spheres spontaneously accumulate at the nodal lines, completely inverting the self-organized particle pattern on the wave. From a potential energy estimate we show (i) that at low ϕ antinode clusters are energetically favorable over nodal ones and (ii) how this situation reverses at high ϕ, in agreement with the experiment.

Infrared dust emission from globular clusters

International Nuclear Information System (INIS)

Angeletti, L.; Capuzzo-Dolcetta, R.; Giannone, P.; Blanco, A.; Bussoletti, E.

1982-01-01

The implications of the presence of a central cloud in the cores of globular clusters were investigated recently. A possible mechanism of confinement of dust in the central region of our cluster models was also explored. The grain temperature and infrared emission have now been computed for rather realistic grain compositions. The grain components were assumed to be graphite and/or silicates. The central clouds turned out to be roughly isothermal. The wavelengths of maximum emission came out to be larger than 20 μm in all studied cases. An application of the theoretical results to five globular clusters showed that the predictable infrared emission for 47 Tuc, M4 and M22 should be detectable by means of present instrumentation aboard flying platforms. (author)

Infrared dust emission from globular clusters

Energy Technology Data Exchange (ETDEWEB)

Angeletti, L; Capuzzo-Dolcetta, R; Giannone, P. (Rome Univ. (Italy). Osservatorio Astronomico); Blanco, A; Bussoletti, E [Lecce Univ. (Italy). Ist. di Fisica

1982-05-01

The implications of the presence of a central cloud in the cores of globular clusters were investigated recently. A possible mechanism of confinement of dust in the central region of our cluster models was also explored. The grain temperature and infrared emission have now been computed for rather realistic grain compositions. The grain components were assumed to be graphite and/or silicates. The central clouds turned out to be roughly isothermal. The wavelengths of maximum emission came out to be larger than 20 ..mu..m in all studied cases. An application of the theoretical results to five globular clusters showed that the predictable infrared emission for 47 Tuc, M4 and M22 should be detectable by means of present instrumentation aboard flying platforms.

Quantum reading capacity

International Nuclear Information System (INIS)

Pirandola, Stefano; Braunstein, Samuel L; Lupo, Cosmo; Mancini, Stefano; Giovannetti, Vittorio

2011-01-01

The readout of a classical memory can be modelled as a problem of quantum channel discrimination, where a decoder retrieves information by distinguishing the different quantum channels encoded in each cell of the memory (Pirandola 2011 Phys. Rev. Lett. 106 090504). In the case of optical memories, such as CDs and DVDs, this discrimination involves lossy bosonic channels and can be remarkably boosted by the use of nonclassical light (quantum reading). Here we generalize these concepts by extending the model of memory from single-cell to multi-cell encoding. In general, information is stored in a block of cells by using a channel-codeword, i.e. a sequence of channels chosen according to a classical code. Correspondingly, the readout of data is realized by a process of ‘parallel’ channel discrimination, where the entire block of cells is probed simultaneously and decoded via an optimal collective measurement. In the limit of a large block we define the quantum reading capacity of the memory, quantifying the maximum number of readable bits per cell. This notion of capacity is nontrivial when we suitably constrain the physical resources of the decoder. For optical memories (encoding bosonic channels), such a constraint is energetic and corresponds to fixing the mean total number of photons per cell. In this case, we are able to prove a separation between the quantum reading capacity and the maximum information rate achievable by classical transmitters, i.e. arbitrary classical mixtures of coherent states. In fact, we can easily construct nonclassical transmitters that are able to outperform any classical transmitter, thus showing that the advantages of quantum reading persist in the optimal multi-cell scenario. (paper)

Construction and Capacity Analysis of High-Rank LoS MIMO Channels in High Speed Railway Scenarios

Directory of Open Access Journals (Sweden)

Jingya Yang

2012-01-01

Full Text Available The validity of the maximum capacity criterion applied to realize high-rank line-of-sight (LoS multiple-input multiple-output (MIMO channels is investigated for high speed railway scenarios. Performance is evaluated by ergodic capacity. Numerical results demonstrate that by simply adjusting antenna spacing according to the maximum capacity criterion, significant capacity gains are achievable. We find relatively low sensitivity of the system to displacements from the optimal point and angle in relatively short range. Thus, we present two proposals to reconfigure antenna arrays so as to maximize LoS MIMO capacity in the high speed railway scenarios

A heuristic approach to handle capacitated facility location problem evaluated using clustering internal evaluation

Science.gov (United States)

Sutanto, G. R.; Kim, S.; Kim, D.; Sutanto, H.

2018-03-01

One of the problems in dealing with capacitated facility location problem (CFLP) is occurred because of the difference between the capacity numbers of facilities and the number of customers that needs to be served. A facility with small capacity may result in uncovered customers. These customers need to be re-allocated to another facility that still has available capacity. Therefore, an approach is proposed to handle CFLP by using k-means clustering algorithm to handle customers’ allocation. And then, if customers’ re-allocation is needed, is decided by the overall average distance between customers and the facilities. This new approach is benchmarked to the existing approach by Liao and Guo which also use k-means clustering algorithm as a base idea to decide the facilities location and customers’ allocation. Both of these approaches are benchmarked by using three clustering evaluation methods with connectedness, compactness, and separations factors.

Clustering and phase transitions on a neutral landscape

Science.gov (United States)

Scott, Adam D.; King, Dawn M.; Marić, Nevena; Bahar, Sonya

2013-06-01

Recent computational studies have shown that speciation can occur under neutral conditions, i.e., when the simulated organisms all have identical fitness. These works bear comparison with mathematical studies of clustering on neutral landscapes in the context of branching and coalescing random walks. Here, we show that sympatric clustering/speciation can occur on a neutral landscape whose dimensions specify only the simulated organisms’ phenotypes. We demonstrate that clustering occurs not only in the case of assortative mating, but also in the case of asexual fission; it is not observed in the control case of random mating. We find that the population size and the number of clusters undergo a second-order non-equilibrium phase transition as the maximum mutation size is varied.

STUDY ON MAXIMUM SPECIFIC SLUDGE ACIVITY OF DIFFERENT ANAEROBIC GRANULAR SLUDGE BY BATCH TESTS

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

The maximum specific sludge activity of granular sludge from large-scale UASB, IC and Biobed anaerobic reactors were investigated by batch tests. The limitation factors related to maximum specific sludge activity (diffusion, substrate sort, substrate concentration and granular size) were studied. The general principle and procedure for the precise measurement of maximum specific sludge activity were suggested. The potential capacity of loading rate of the IC and Biobed anaerobic reactors were analyzed and compared by use of the batch tests results.

The composite sequential clustering technique for analysis of multispectral scanner data

Science.gov (United States)

Su, M. Y.

1972-01-01

The clustering technique consists of two parts: (1) a sequential statistical clustering which is essentially a sequential variance analysis, and (2) a generalized K-means clustering. In this composite clustering technique, the output of (1) is a set of initial clusters which are input to (2) for further improvement by an iterative scheme. This unsupervised composite technique was employed for automatic classification of two sets of remote multispectral earth resource observations. The classification accuracy by the unsupervised technique is found to be comparable to that by traditional supervised maximum likelihood classification techniques. The mathematical algorithms for the composite sequential clustering program and a detailed computer program description with job setup are given.

Pullout capacity of batter pile in sand.

Science.gov (United States)

Nazir, Ashraf; Nasr, Ahmed

2013-03-01

Many offshore structures are subjected to overturning moments due to wind load, wave pressure, and ship impacts. Also most of retaining walls are subjected to horizontal forces and bending moments, these forces are due to earth pressure. For foundations in such structures, usually a combination of vertical and batter piles is used. Little information is available in the literature about estimating the capacity of piles under uplift. In cases where these supporting piles are not vertical, the behavior under axial pullout is not well established. In order to delineate the significant variables affecting the ultimate uplift shaft resistance of batter pile in dry sand, a testing program comprising 62 pullout tests was conducted. The tests are conducted on model steel pile installed in loose, medium, and dense sand to an embedded depth ratio, L/d, vary from 7.5 to 30 and with various batter angles of 0°, 10°, 20°, and 30°. Results indicate that the pullout capacity of a batter pile constructed in dense and/or medium density sand increases with the increase of batter angle attains maximum value and then decreases, the maximum value of Pα occurs at batter angle approximately equal to 20°, and it is about 21-31% more than the vertical pile capacity, while the pullout capacity for batter pile that constructed in loose sand decreases with the increase of pile inclination. The results also indicated that the circular pile is more resistant to pullout forces than the square and rectangular pile shape. The rough model piles tested is experienced 18-75% increase in capacity compared with the smooth model piles. The suggested relations for the pullout capacity of batter pile regarding the vertical pile capacity are well predicted.

Pullout capacity of batter pile in sand

Directory of Open Access Journals (Sweden)

Ashraf Nazir

2013-03-01

Full Text Available Many offshore structures are subjected to overturning moments due to wind load, wave pressure, and ship impacts. Also most of retaining walls are subjected to horizontal forces and bending moments, these forces are due to earth pressure. For foundations in such structures, usually a combination of vertical and batter piles is used. Little information is available in the literature about estimating the capacity of piles under uplift. In cases where these supporting piles are not vertical, the behavior under axial pullout is not well established. In order to delineate the significant variables affecting the ultimate uplift shaft resistance of batter pile in dry sand, a testing program comprising 62 pullout tests was conducted. The tests are conducted on model steel pile installed in loose, medium, and dense sand to an embedded depth ratio, L/d, vary from 7.5 to 30 and with various batter angles of 0°, 10°, 20°, and 30°. Results indicate that the pullout capacity of a batter pile constructed in dense and/or medium density sand increases with the increase of batter angle attains maximum value and then decreases, the maximum value of Pα occurs at batter angle approximately equal to 20°, and it is about 21–31% more than the vertical pile capacity, while the pullout capacity for batter pile that constructed in loose sand decreases with the increase of pile inclination. The results also indicated that the circular pile is more resistant to pullout forces than the square and rectangular pile shape. The rough model piles tested is experienced 18–75% increase in capacity compared with the smooth model piles. The suggested relations for the pullout capacity of batter pile regarding the vertical pile capacity are well predicted.

Clustering of near clusters versus cluster compactness

International Nuclear Information System (INIS)

Yu Gao; Yipeng Jing

1989-01-01

The clustering properties of near Zwicky clusters are studied by using the two-point angular correlation function. The angular correlation functions for compact and medium compact clusters, for open clusters, and for all near Zwicky clusters are estimated. The results show much stronger clustering for compact and medium compact clusters than for open clusters, and that open clusters have nearly the same clustering strength as galaxies. A detailed study of the compactness-dependence of correlation function strength is worth investigating. (author)

Bioinformatics and Astrophysics Cluster (BinAc)

Science.gov (United States)

Krüger, Jens; Lutz, Volker; Bartusch, Felix; Dilling, Werner; Gorska, Anna; Schäfer, Christoph; Walter, Thomas

2017-09-01

BinAC provides central high performance computing capacities for bioinformaticians and astrophysicists from the state of Baden-Württemberg. The bwForCluster BinAC is part of the implementation concept for scientific computing for the universities in Baden-Württemberg. Community specific support is offered through the bwHPC-C5 project.

An Experimental Observation of Axial Variation of Average Size of Methane Clusters in a Gas Jet

International Nuclear Information System (INIS)

Ji-Feng, Han; Chao-Wen, Yang; Jing-Wei, Miao; Jian-Feng, Lu; Meng, Liu; Xiao-Bing, Luo; Mian-Gong, Shi

2010-01-01

Axial variation of average size of methane clusters in a gas jet produced by supersonic expansion of methane through a cylindrical nozzle of 0.8 mm in diameter is observed using a Rayleigh scattering method. The scattered light intensity exhibits a power scaling on the backing pressure ranging from 16 to 50 bar, and the power is strongly Z dependent varying from 8.4 (Z = 3 mm) to 5.4 (Z = 11 mm), which is much larger than that of the argon cluster. The scattered light intensity versus axial position shows that the position of 5 mm has the maximum signal intensity. The estimation of the average cluster size on axial position Z indicates that the cluster growth process goes forward until the maximum average cluster size is reached at Z = 9 mm, and the average cluster size will decrease gradually for Z > 9 mm

Evaluation model for safety capacity of chemical industrial park based on acceptable regional risk

Institute of Scientific and Technical Information of China (English)

Guohua Chen; Shukun Wang; Xiaoqun Tan

2015-01-01

The paper defines the Safety Capacity of Chemical Industrial Park (SCCIP) from the perspective of acceptable regional risk. For the purpose of exploring the evaluation model for the SCCIP, a method based on quantitative risk assessment was adopted for evaluating transport risk and to confirm reasonable safety transport capacity of chemical industrial park, and then by combining with the safety storage capacity, a SCCIP evaluation model was put forward. The SCCIP was decided by the smaller one between the largest safety storage capacity and the maximum safety transport capacity, or else, the regional risk of the park will exceed the acceptable level. The developed method was applied to a chemical industrial park in Guangdong province to obtain the maximum safety transport capacity and the SCCIP. The results can be realized in the regional risk control of the park effectively.

Cluster-cluster clustering

International Nuclear Information System (INIS)

Barnes, J.; Dekel, A.; Efstathiou, G.; Frenk, C.S.; Yale Univ., New Haven, CT; California Univ., Santa Barbara; Cambridge Univ., England; Sussex Univ., Brighton, England)

1985-01-01

The cluster correlation function xi sub c(r) is compared with the particle correlation function, xi(r) in cosmological N-body simulations with a wide range of initial conditions. The experiments include scale-free initial conditions, pancake models with a coherence length in the initial density field, and hybrid models. Three N-body techniques and two cluster-finding algorithms are used. In scale-free models with white noise initial conditions, xi sub c and xi are essentially identical. In scale-free models with more power on large scales, it is found that the amplitude of xi sub c increases with cluster richness; in this case the clusters give a biased estimate of the particle correlations. In the pancake and hybrid models (with n = 0 or 1), xi sub c is steeper than xi, but the cluster correlation length exceeds that of the points by less than a factor of 2, independent of cluster richness. Thus the high amplitude of xi sub c found in studies of rich clusters of galaxies is inconsistent with white noise and pancake models and may indicate a primordial fluctuation spectrum with substantial power on large scales. 30 references

Manipulation of Microbubble Clusters Using Focused Ultrasound

Science.gov (United States)

Matsuzaki, Hironobu; Osaki, Taichi; Kawaguchi, Kei; Unga, Johan; Ichiyanagi, Mitsuhisa; Azuma, Takashi; Suzuki, Ryo; Maruyama, Kazuo; Takagi, Shu

2017-11-01

In recent years, microbubbles (MBs) are expected to be utilized for the ultrasound drug delivery system (DDS). For the MB-DDS, it is important to establish a method of controlling bubbles and bubble clusters using ultrasound field. The objective of this study is to clarify behaviors of bubble clusters with various physical conditions. MBs in the ultrasound field are subjected to the primary Bjerknes force. The force traps MBs at the focal region of the focused ultrasound field. The trapped MBs form a bubble cluster at the region. A bubble cluster continues growing with absorbing surrounding bubbles until it reaches a maximum size beyond which it disappears from the focal region. In the present study, two kinds of MBs are used for the experiment. One is Sonazoid with average diameter of 2.6 um and resonant frequency of 5 MHz. The other is developed by Teikyo Univ., with average diameter of 1.5 um and presumed resonant frequency of 4 MHz. The bubble cluster's behaviors are analyzed using the high-speed camera. Sonazoid clusters have larger critical size than the other in every frequency, and its cluster size is inversely proportional to the ultrasound frequency, while Teikyo-bubble clusters have different tendency. These results are discussed in the presentation.

Dual capacity reciprocating compressor

Science.gov (United States)

Wolfe, Robert W.

1984-01-01

A multi-cylinder compressor 10 particularly useful in connection with northern climate heat pumps and in which different capacities are available in accordance with reversing motor 16 rotation is provided with an eccentric cam 38 on a crank pin 34 under a fraction of the connecting rods, and arranged for rotation upon the crank pin between opposite positions 180.degree. apart so that with cam rotation on the crank pin such that the crank throw is at its normal maximum value all pistons pump at full capacity, and with rotation of the crank shaft in the opposite direction the cam moves to a circumferential position on the crank pin such that the overall crank throw is zero. Pistons 24 whose connecting rods 30 ride on a crank pin 36 without a cam pump their normal rate with either crank rotational direction. Thus a small clearance volume is provided for any piston that moves when in either capacity mode of operation.

OPPORTUNITIES FOR ORGANISING CLUSTERS IN THE BULGARIAN GRAPE-WINE SECTOR

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Albena MITEVA

2015-04-01

Full Text Available Bulgaria's membership in the European Union defines the development of clusters as a key element of the National Strategy for increasing the competitiveness. The role of the clusters becomes especially important at this time because SME do not have the capacity to meet EU requirements and to survive without uniting themselves. Moreover the National Strategy for Vine-wine Sector in Bulgaria stipulates the transformation of the sector in a leading one and securing a decent place of Bulgarian wines on international market which may be succeed through cluster introduction in the sector. In the paper is presented an overview of the initiatives for cluster development in the Bulgarian grape-wine sector and are disclosed the structure and role of cluster participants.

Inhibition delay increases neural network capacity through Stirling transform

Science.gov (United States)

Nogaret, Alain; King, Alastair

2018-03-01

Inhibitory neural networks are found to encode high volumes of information through delayed inhibition. We show that inhibition delay increases storage capacity through a Stirling transform of the minimum capacity which stabilizes locally coherent oscillations. We obtain both the exact and asymptotic formulas for the total number of dynamic attractors. Our results predict a (ln2) -N-fold increase in capacity for an N -neuron network and demonstrate high-density associative memories which host a maximum number of oscillations in analog neural devices.

Building a cluster computer for the computing grid of tomorrow

International Nuclear Information System (INIS)

Wezel, J. van; Marten, H.

2004-01-01

The Grid Computing Centre Karlsruhe takes part in the development, test and deployment of hardware and cluster infrastructure, grid computing middleware, and applications for particle physics. The construction of a large cluster computer with thousands of nodes and several PB data storage capacity is a major task and focus of research. CERN based accelerator experiments will use GridKa, one of only 8 world wide Tier-1 computing centers, for its huge computer demands. Computing and storage is provided already for several other running physics experiments on the exponentially expanding cluster. (orig.)

A theoretical model to determine the capacity performance of shape-specific electrodes

Science.gov (United States)

Yue, Yuan; Liang, Hong

2018-06-01

A theory is proposed to explain and predict the electrochemical process during reaction between lithium ions and electrode materials. In the model, the process of reaction is proceeded into two steps, surface adsorption and diffusion of lithium ions. The surface adsorption is an instantaneous process for lithium ions to adsorb onto the surface sites of active materials. The diffusion of lithium ions into particles is determined by the charge-discharge condition. A formula to determine the maximum specific capacity of active materials at different charging rates (C-rates) is derived. The maximum specific capacity is correlated to characteristic parameters of materials and cycling - such as size, aspect ratio, surface area, and C-rate. Analysis indicates that larger particle size or greater aspect ratio of active materials and faster C-rates can reduce maximum specific capacity. This suggests that reducing particle size of active materials and slowing the charge-discharge speed can provide enhanced electrochemical performance of a battery cell. Furthermore, the model is validated by published experimental results. This model brings new understanding in quantification of electrochemical kinetics and capacity performance. It enables development of design strategies for novel electrodes and future generation of energy storage devices.

Developing cluster strategy of apples dodol SMEs by integration K-means clustering and analytical hierarchy process method

Science.gov (United States)

Mustaniroh, S. A.; Effendi, U.; Silalahi, R. L. R.; Sari, T.; Ala, M.

2018-03-01

The purposes of this research were to determine the grouping of apples dodol small and medium enterprises (SMEs) in Batu City and to determine an appropriate development strategy for each cluster. The methods used for clustering SMEs was k-means. The Analytical Hierarchy Process (AHP) approach was then applied to determine the development strategy priority for each cluster. The variables used in grouping include production capacity per month, length of operation, investment value, average sales revenue per month, amount of SMEs assets, and the number of workers. Several factors were considered in AHP include industry cluster, government, as well as related and supporting industries. Data was collected using the methods of questionaire and interviews. SMEs respondents were selected among SMEs appels dodol in Batu City using purposive sampling. The result showed that two clusters were formed from five apples dodol SMEs. The 1stcluster of apples dodol SMEs, classified as small enterprises, included SME A, SME C, and SME D. The 2ndcluster of SMEs apples dodol, classified as medium enterprises, consisted of SME B and SME E. The AHP results indicated that the priority development strategy for the 1stcluster of apples dodol SMEs was improving quality and the product standardisation, while for the 2nd cluster was increasing the marketing access.

Carrying capacity of Chaetoceros gracilis in Homa Lagoon and the ...

African Journals Online (AJOL)

The possibility for nutrient limitation to affect C. gracilis was assessed from two different ecosystems (Izmir Bay and Homa Lagoon). Our goal was to determine the growth rate of all nutrients and the maximum levels of the C. gracilis phytoplankton biomass (the maximum biomass carrying capacity) on the extent of its full ...

Modification of MSDR algorithm and ITS implementation on graph clustering

Science.gov (United States)

Prastiwi, D.; Sugeng, K. A.; Siswantining, T.

2017-07-01

Maximum Standard Deviation Reduction (MSDR) is a graph clustering algorithm to minimize the distance variation within a cluster. In this paper we propose a modified MSDR by replacing one technical step in MSDR which uses polynomial regression, with a new and simpler step. This leads to our new algorithm called Modified MSDR (MMSDR). We implement the new algorithm to separate a domestic flight network of an Indonesian airline into two large clusters. Further analysis allows us to discover a weak link in the network, which should be improved by adding more flights.

Efficient heuristics for maximum common substructure search.

Science.gov (United States)

Englert, Péter; Kovács, Péter

2015-05-26

Maximum common substructure search is a computationally hard optimization problem with diverse applications in the field of cheminformatics, including similarity search, lead optimization, molecule alignment, and clustering. Most of these applications have strict constraints on running time, so heuristic methods are often preferred. However, the development of an algorithm that is both fast enough and accurate enough for most practical purposes is still a challenge. Moreover, in some applications, the quality of a common substructure depends not only on its size but also on various topological features of the one-to-one atom correspondence it defines. Two state-of-the-art heuristic algorithms for finding maximum common substructures have been implemented at ChemAxon Ltd., and effective heuristics have been developed to improve both their efficiency and the relevance of the atom mappings they provide. The implementations have been thoroughly evaluated and compared with existing solutions (KCOMBU and Indigo). The heuristics have been found to greatly improve the performance and applicability of the algorithms. The purpose of this paper is to introduce the applied methods and present the experimental results.

Research on configuration of railway self-equipped tanker based on minimum cost maximum flow model

Science.gov (United States)

Yang, Yuefang; Gan, Chunhui; Shen, Tingting

2017-05-01

In the study of the configuration of the tanker of chemical logistics park, the minimum cost maximum flow model is adopted. Firstly, the transport capacity of the park loading and unloading area and the transportation demand of the dangerous goods are taken as the constraint condition of the model; then the transport arc capacity, the transport arc flow and the transport arc edge weight are determined in the transportation network diagram; finally, the software calculations. The calculation results show that the configuration issue of the tankers can be effectively solved by the minimum cost maximum flow model, which has theoretical and practical application value for tanker management of railway transportation of dangerous goods in the chemical logistics park.

Lung function profiles and aerobic capacity of adult cigarette and ...

African Journals Online (AJOL)

Lung function profiles and aerobic capacity of adult cigarette and hookah smokers after 12 weeks intermittent training. ... All subjects performed 30 min of interval exercise (2 min of work followed by 1 min of rest) three times a week for 12 weeks at an intensity estimated at 70% of the subject's maximum aerobic capacity ...

Pattern of language-related potential maps in cluster and noncluster initial consonants in consonant-vowel (CV syllables

Directory of Open Access Journals (Sweden)

Naiphinich Kotchabhakdi

2006-09-01

Full Text Available Mismatch negativity (MMN was used to investigate the processing of cluster and noncluster initial consonants in consonant vowel syllables in the human brain. The MMN was elicited by either syllable with cluster or noncluster initial consonant, phonetic contrasts being identical in both syllables. Compared to the noncluster consonant, the cluster consonant elicited a more prominent MMN. The MMN to the cluster consonant occurred later than that of the noncluster consonant. The topography of the mismatch responses showed clear left-hemispheric laterality in both syllables. However, the syllable with an initial noncluster consonant stimulus produced MMN maximum over the middle temporal gyrus, whereas maximum of the MMN activated by the syllable with initial cluster consonant was observed over the superior temporal gyrus. We suggest that the MMN component in consonant-vowel syllables is more sensitive to cluster compared to noncluster initial consonants. Spatial and temporal features of the cluster consonant indicate delayed activation of left-lateralized perisylvian cell assemblies that function as cortical memory traces of cluster initial consonant in consonant-vowel syllables.

High-Intensity Femtosecond Laser Interaction with Rare Gas Clusters

Institute of Scientific and Technical Information of China (English)

林亚风; 钟钦; 曾淳; 陈哲

2001-01-01

With a 45 fs multiterawatt 790 nm laser system and jets of argon and krypton atomic clusters, a study of the interaction of fs intense laser pulses with large size rare gas dusters was conducted. The maximum laser intensity of about 7 × 1016 W/cm2 and dusters composed of thousands of atoms which were determined through Rayleigh scattering measurements were involved inthe experiments. On the one hand, the results indicate that the interaction is strongly cluster size dependent. The stronger the interaction, the larger the clusters are. On the other hand, a saturation followed by a drop of the energy of ions ejected from the interaction will occur when the laser intensity exceeds a definite value for clusters of a certain size.

Building the capacity of family day care educators to promote children's social and emotional wellbeing: an exploratory cluster randomised controlled trial

Directory of Open Access Journals (Sweden)

Sims Margaret

2011-11-01

Full Text Available Abstract Background Childhood mental health problems are highly prevalent, experienced by one in five children living in socioeconomically disadvantaged families. Although childcare settings, including family day care are ideal to promote children's social and emotional wellbeing at a population level in a sustainable way, family day care educators receive limited training in promoting children's mental health. This study is an exploratory wait-list control cluster randomised controlled trial to test the appropriateness, acceptability, cost, and effectiveness of "Thrive," an intervention program to build the capacity of family day care educators to promote children's social and emotional wellbeing. Thrive aims to increase educators' knowledge, confidence and skills in promoting children's social and emotional wellbeing. Methods/Design This study involves one family day care organisation based in a low socioeconomic area of Melbourne. All family day care educators (term used for registered carers who provide care for children for financial reimbursement in the carers own home are eligible to participate in the study. The clusters for randomisation will be the fieldworkers (n = 5 who each supervise 10-15 educators. The intervention group (field workers and educators will participate in a variety of intervention activities over 12 months, including workshops; activity exchanges with other educators; and focused discussion about children's social and emotional wellbeing during field worker visits. The control group will continue with their normal work practice. The intervention will be delivered to the intervention group and then to the control group after a time delay of 15 months post intervention commencement. A baseline survey will be conducted with all consenting educators and field workers (n = ~70 assessing outcomes at the cluster and individual level. The survey will also be administered at one month, six months and 12 months post

Strategic process strengthens and orientates the regional RandD capacity

Energy Technology Data Exchange (ETDEWEB)

Knuuttila, Kirsi [JAMK Univ. of Applied Sciences, Jyvaeskylae (Finland)], e-mail: kirsi.knuuttila@jamk.fi; Krissakova, Ingrid [National Forest Centre-Forest Research Inst., Zvolen (Slovakia); Barbena, Goizeder [Centro Nacional de Energias Renovables/ Departamento de Biomasa, CENER, Pamplona (Spain); Hryniewicz, Marek [Inst. of Technology and Life Sciences, ITP, Raszyn (Poland); Ketikidis, Chrysovalantis [Centre for Research and Technology Hellas, CERTH/ Inst. for Solid Fuels Technology and Applications, Thessaloniki (Greece); Wihersaari, Margareta [Jyvaeskylae Univ., Jyvaeskylae (Finland)

2012-11-01

The use of biomasses and competition for biomass resources are rapidly increasing in Europe due to the positive environmental advantages that this energy source entails, including climate change prevention. Central Finland, Navarra (Spain), Western Macedonia (Greece), Slovakia and Wielkopolska (Poland) have taken the joint initiative to strengthen the regional expertise, cooperation capacities and innovation environment in the field of sustainable use of biomass resources. The initiative to develop the regional research driven clusters is supported by BIOCLUS project (www.bioclus.eu) co-financed by FP7 Regions of Knowledge Programme. The biomass research orientated clusters have built up Regional Strategic RandD Agendas (SRA) and Joint Action Plans (JAP) based on the SRAs. The starting point for SRA is the comprehensive understanding of regional biomass resources. SRA and JAP process orientates and strengthens research activities and capacity building in the selected research fields related to sustainable use of biomass. The agenda supports expertise development and cooperation in the regional research-driven cluster. It identifies the focus of research activities in the future and supports the authorities in directing the use of human and financial resources.

Capacity competition in electricity markets

International Nuclear Information System (INIS)

Crampes, Claude; Creti, Anna

2005-01-01

The article analyzed a two-stage game where capacity constrained electricity generators first choose how much capacity they make available and then compete in a uniform-rice auction. It is studied how capacity withholding can be used strategically to enforce market power and how uniform auctions in the price game change the results of capacity constrained competition models. The uniform auction procedure gives strong incentives to capacity restriction. At equilibrium, however, power shortage never occurs. Though auctions in electricity markets have already been studied by several economists, yet an important feature of spot trading is the capacity availability decision. In fact, for technical reasons, such as equipment maintenance or failures, the installed capacity may not work at maximum operating level and the spot market rules oblige generators to announce which plants they are willing to use and simultaneously their offer prices. Beside technical reasons, the so-called 'capacity declarations' also offer a strategic instrument for firms: by restricting capacity, operators can benefit from scarcity rents. Assessing whether generators withhold capacity is an intriguing issue for real electricity markets, though proving it is a difficult task. Several theoretical papers show that generators are able to keep wholesale prices high as compared to their generation costs. In our model, a generator is not obliged to declare all installed capacity as available, but decides on the amount of MW of electricity that is available. Hence the available capacity is an endogenous variable while the installed one is exogenous. The distinction between installed capacities and 'available' capacities allows to explain clearly whether generators exert market power by declaring unavailable some production units. Although we find multiple sub game perfect equilibria that cannot be eliminated by Pareto-dominance, all the outcomes are characterized by market price at the highest

Heat capacity characterization at phase transition temperature of Agl superionic

International Nuclear Information System (INIS)

Widowati, Arie

2000-01-01

The phase transition of Agl superionic conductor was investigated by calorometric. A single phase transition was found at (153±5) o C which corresponds to the α - β transition. Calorimetric measurement showed an anomalously high heat capacity with a large discontinues change in the Arrhenius plot, was found above the transition temperature of β - α phase. The maximum heat capacity was found to be ±19.7 cal/gmol. Key words : superionic conductor, thermal capacity

Heat capacity of the neutron star inner crust within an extended nuclear statistical equilibrium model

Science.gov (United States)

Burrello, S.; Gulminelli, F.; Aymard, F.; Colonna, M.; Raduta, Ad. R.

2015-11-01

Background: Superfluidity in the crust is a key ingredient for the cooling properties of proto-neutron stars. Present theoretical calculations employ the quasiparticle mean-field Hartree-Fock-Bogoliubov theory with temperature-dependent occupation numbers for the quasiparticle states. Purpose: Finite temperature stellar matter is characterized by a whole distribution of different nuclear species. We want to assess the importance of this distribution on the calculation of heat capacity in the inner crust. Method: Following a recent work, the Wigner-Seitz cell is mapped into a model with cluster degrees of freedom. The finite temperature distribution is then given by a statistical collection of Wigner-Seitz cells. We additionally introduce pairing correlations in the local density BCS approximation both in the homogeneous unbound neutron component, and in the interface region between clusters and neutrons. Results: The heat capacity is calculated in the different baryonic density conditions corresponding to the inner crust, and in a temperature range varying from 100 KeV to 2 MeV. We show that accounting for the cluster distribution has a small effect at intermediate densities, but it considerably affects the heat capacity both close to the outer crust and close to the core. We additionally show that it is very important to consider the temperature evolution of the proton fraction for a quantitatively reliable estimation of the heat capacity. Conclusions: We present the first modelization of stellar matter containing at the same time a statistical distribution of clusters at finite temperature, and pairing correlations in the unbound neutron component. The effect of the nuclear distribution on the superfluid properties can be easily added in future calculations of the neutron star cooling curves. A strong influence of resonance population on the heat capacity at high temperature is observed, which deserves to be further studied within more microscopic calculations.

Ionic cluster size distributions of swollen nafion/sulfated beta-cyclodextrin membranes characterized by nuclear magnetic resonance cryoporometry.

Science.gov (United States)

Jeon, Jae-Deok; Kwak, Seung-Yeop

2007-08-16

Nafion/sb-CD membranes were prepared by mixing 5 wt% Nafion solution with H+-form sulfated beta-cyclodextrin (sb-CD), and their water uptakes, ion exchange capacities (IECs), and ionic cluster size distributions were measured. Gravimetric and thermogravimetric measurements showed that the water uptake of the membranes increased with increases in their sb-CD content. The IECs of the membrane were measured with acid-base titration and found to increase with increases in the sb-CD content, reaching 0.96 mequiv/g for NC5 ("NCx" denotes a Nafion/sb-CD composite membrane containing x wt% of sb-CD). The cluster-correlation peaks and ionic cluster size distributions of the water-swollen membranes were determined using small-angle X-ray scattering (SAXS) and 1H nuclear magnetic resonance (NMR) cryoporometry, respectively. The SAXS experiments confirmed that increases in the sb-CD content of the membranes shifted the maximum SAXS peaks to lower angles, indicating an increase in the cluster correlation peak. NMR cryoporometry is based on the theory of the melting point depression, Delta Tm, of a liquid confined within a pore, which is dependent on the pore diameter. The melting point depression was determined by analyzing the variation of the NMR signal intensity with temperature. Our analysis of the intensity-temperature (IT) curves showed that the ionic cluster size distribution gradually became broader with increases in the membrane sb-CD content due to the increased water content, indicating an increase in the ionic cluster size. This result indicates that the presence of sb-CD with its many sulfonic acid sites in the Nafion membranes results in increases in the ionic cluster size as well as in the water uptake and the IEC. We conclude that NMR cryoporometry provides a method for determining the ionic cluster size on the nanometer scale in an aqueous environment, which cannot be obtained using other methods.

Exercise therapy improves aerobic capacity of inpatients with major depressive disorder.

Science.gov (United States)

Kerling, Arno; von Bohlen, Anne; Kück, Momme; Tegtbur, Uwe; Grams, Lena; Haufe, Sven; Gützlaff, Elke; Kahl, Kai G

2016-06-01

Unipolar depression is one of the most common diseases worldwide and is associated with a higher cardiovascular risk partly due to reduced aerobic capacity. Therefore, the aim of our study was to examine whether a structured aerobic training program can improve aerobic capacity in inpatients with MDD (major depressive disorder). Overall, 25 patients (13 women, 12 men) diagnosed with MDD were included in the study. Parameters of aerobic capacity, such as maximum performance, maximum oxygen consumption, and VAT (ventilatory anaerobic threshold), were assessed on a bicycle ergometer before and 6 weeks after a training period (three times per week for 45 min on two endurance machines). In addition, a constant load test was carried out at 50% of the maximum performance prior to and after the training period. The performance data were compared with 25 healthy controls matched for sex, age, and body mass index before and after the training period. Compared to controls, patients with MDD had significantly lower aerobic capacity. After training, there was a significant improvement in their performance data. A significant difference remained only for VAT between patients with MDD and healthy controls. With regard to the coincidence of MDD with cardiovascular and cardiometabolic disorders, a structured supervised exercise program carried out during hospitalization is a useful supplement for patients with MDD.

Supervised maximum-likelihood weighting of composite protein networks for complex prediction

Directory of Open Access Journals (Sweden)

Yong Chern Han

2012-12-01

Full Text Available Abstract Background Protein complexes participate in many important cellular functions, so finding the set of existent complexes is essential for understanding the organization and regulation of processes in the cell. With the availability of large amounts of high-throughput protein-protein interaction (PPI data, many algorithms have been proposed to discover protein complexes from PPI networks. However, such approaches are hindered by the high rate of noise in high-throughput PPI data, including spurious and missing interactions. Furthermore, many transient interactions are detected between proteins that are not from the same complex, while not all proteins from the same complex may actually interact. As a result, predicted complexes often do not match true complexes well, and many true complexes go undetected. Results We address these challenges by integrating PPI data with other heterogeneous data sources to construct a composite protein network, and using a supervised maximum-likelihood approach to weight each edge based on its posterior probability of belonging to a complex. We then use six different clustering algorithms, and an aggregative clustering strategy, to discover complexes in the weighted network. We test our method on Saccharomyces cerevisiae and Homo sapiens, and show that complex discovery is improved: compared to previously proposed supervised and unsupervised weighting approaches, our method recalls more known complexes, achieves higher precision at all recall levels, and generates novel complexes of greater functional similarity. Furthermore, our maximum-likelihood approach allows learned parameters to be used to visualize and evaluate the evidence of novel predictions, aiding human judgment of their credibility. Conclusions Our approach integrates multiple data sources with supervised learning to create a weighted composite protein network, and uses six clustering algorithms with an aggregative clustering strategy to

Clustering aspects in nuclear structure functions

International Nuclear Information System (INIS)

Hirai, M.; Saito, K.; Watanabe, T.; Kumano, S.

2011-01-01

For understanding an anomalous nuclear effect experimentally observed for the beryllium-9 nucleus at the Thomas Jefferson National Accelerator Facility, clustering aspects are studied in structure functions of deep inelastic lepton-nucleus scattering by using momentum distributions calculated in antisymmetrized (or fermionic) molecular dynamics (AMD) and also in a simple shell model for comparison. According to AMD, the 9 Be nucleus consists of two α-like clusters with a surrounding neutron. The clustering produces high-momentum components in nuclear wave functions, which affects nuclear modifications of the structure functions. We investigated whether clustering features could appear in the structure function F 2 of 9 Be along with studies for other light nuclei. We found that nuclear modifications of F 2 are similar in both AMD and shell models within our simple convolution description although there are slight differences in 9 Be. It indicates that the anomalous 9 Be result should be explained by a different mechanism from the nuclear binding and Fermi motion. If nuclear-modification slopes d(F 2 A /F 2 D )/dx are shown by the maximum local densities, the 9 Be anomaly can be explained by the AMD picture, namely by the clustering structure, whereas it certainly cannot be described in the simple shell model. This fact suggests that the large nuclear modification in 9 Be should be explained by large densities in the clusters. For example, internal nucleon structure could be modified in the high-density clusters. The clustering aspect of nuclear structure functions is an unexplored topic which is interesting for future investigations.

REGIONAL DEVELOPMENT BASED ON CLUSTER IN LIVESTOCK DEVELOPMENT. CLUSTER IN LIVESTOCK SECTOR IN THE KYRGYZ REPUBLIC

Directory of Open Access Journals (Sweden)

Meerim SYDYKOVA

2014-11-01

Full Text Available In most developing countries, where agriculture is the main economical source, clusters have been found as a booster to develop their economy. The Asian countries are now starting to implement agro-food clusters into the mainstream of changes in agriculture, farming and food industry. The long-term growth of meat production in the Kyrgyz Republic during the last decade, as well as the fact that agriculture has become one of the prioritized sectors of the economy, proved the importance of livestock sector in the economy of the Kyrgyz Republic. The research question is “Does the Kyrgyz Republic has strong economic opportunities and prerequisites in agriculture in order to implement an effective agro cluster in the livestock sector?” Paper focuses on describing the prerequisites of the Kyrgyz Republic in agriculture to implement livestock cluster. The main objective of the paper is to analyse the livestock sector of the Kyrgyz Republic and observe the capacity of this sector to implement agro-cluster. The study focuses on investigating livestock sector and a complex S.W.O.T. The analysis was carried out based on local and regional database and official studies. The results of research demonstrate the importance of livestock cluster for national economy. It can be concluded that cluster implementation could provide to its all members with benefits if they could build strong collaborative relationship in order to facilitate the access to the labour market and implicitly, the access to exchange of good practices. Their ability of potential cluster members to act as a convergence pole is critical for acquiring practical skills necessary for the future development of the livestock sector.

Phase correlation and clustering of a nearest neighbour coupled oscillators system

CERN Document Server

Ei-Nashar, H F

2002-01-01

We investigated the phases in a system of nearest neighbour coupled oscillators before complete synchronization in frequency occurs. We found that when oscillators under the influence of coupling form a cluster of the same time-average frequency, their phases start to correlate. An order parameter, which measures this correlation, starts to grow at this stage until it reaches maximum. This means that a time-average phase locked state is reached between the oscillators inside the cluster of the same time- average frequency. At this strength the cluster attracts individual oscillators or a cluster to join in. We also observe that clustering in averaged frequencies orders the phases of the oscillators. This behavior is found at all the transition points studied.

Phase correlation and clustering of a nearest neighbour coupled oscillators system

International Nuclear Information System (INIS)

EI-Nashar, Hassan F.

2002-09-01

We investigated the phases in a system of nearest neighbour coupled oscillators before complete synchronization in frequency occurs. We found that when oscillators under the influence of coupling form a cluster of the same time-average frequency, their phases start to correlate. An order parameter, which measures this correlation, starts to grow at this stage until it reaches maximum. This means that a time-average phase locked state is reached between the oscillators inside the cluster of the same time- average frequency. At this strength the cluster attracts individual oscillators or a cluster to join in. We also observe that clustering in averaged frequencies orders the phases of the oscillators. This behavior is found at all the transition points studied. (author)

Anvil Productivities of Tropical Deep Convective Clusters and Their Regional Differences

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Deng Min

2016-01-01

The total anvil clouds detrained from convection counts for 0.4 to 0.8 of the cluster horizontal scale, 0.2 to 0.6 of the cluster cross section volume, and 0.05 to 0.20 of the cluster ice mass, depending on the cluster scales and height. There are two main detrainment layers. When the convective clusters is less than about 100 km, the anvil clouds are mainly detrained at about 6-8 km with a spreading ratio (ratio of maximum cluster width to convection rainy core width less than 1.5. When convective clusters becomes 100 km or wider, it reaches the dominate detrainment layer at about 12 km, the detrainment index increase from 2 to more 6. Among 8 regions, convection clusters in MA produce the most anvil volume fraction. The more the ice mass is pumped upward in the anvil clouds till clusters are about 500 km wider. Nevertheless, the anvil ice mass pumped above 15 km is less than 0.1% of the total ice mass in the convective cluster.

Overview of Maximum Power Point Tracking Techniques for Photovoltaic Energy Production Systems

DEFF Research Database (Denmark)

Koutroulis, Eftichios; Blaabjerg, Frede

2015-01-01

A substantial growth of the installed photovoltaic systems capacity has occurred around the world during the last decade, thus enhancing the availability of electric energy in an environmentally friendly way. The maximum power point tracking technique enables maximization of the energy production...... of photovoltaic sources during stochastically varying solar irradiation and ambient temperature conditions. Thus, the overall efficiency of the photovoltaic energy production system is increased. Numerous techniques have been presented during the last decade for implementing the maximum power point tracking...... process in a photovoltaic system. This article provides an overview of the operating principles of these techniques, which are suited for either uniform or non-uniform solar irradiation conditions. The operational characteristics and implementation requirements of these maximum power point tracking...

Cluster size matters: Size-driven performance of subnanometer clusters in catalysis, electrocatalysis and Li-air batteries

Science.gov (United States)

Vajda, Stefan

2015-03-01

This paper discusses the strongly size-dependent performance of subnanometer cluster based catalysts in 1) heterogeneous catalysis, 2) electrocatalysis and 3) Li-air batteries. The experimental studies are based on I. fabrication of ultrasmall clusters with atomic precision control of particle size and their deposition on oxide and carbon based supports; II. test of performance, III. in situand ex situ X-ray characterization of cluster size, shape and oxidation state; and IV.electron microscopies. Heterogeneous catalysis. The pronounced effect of cluster size and support on the performance of the catalyst (catalyst activity and the yield of Cn products) will be illustrated on the example of nickel and cobalt clusters in Fischer-Tropsch reaction. Electrocatalysis. The study of the oxygen evolution reaction (OER) on size-selected palladium clusters supported on ultrananocrystalline diamond show pronounced size effects. While Pd4 clusters show no reaction, Pd6 and Pd17 clusters are among the most active catalysts known (in in terms of turnover rate per Pd atom). The system (soft-landed Pd4, Pd6, or Pd17 clusters on an UNCD Si coated electrode) shows stable electrochemical potentials over several cycles, and the characterization of the electrodes show no evidence for evolution or dissolution of either the support Theoretical calculations suggest that this striking difference may be a demonstration that bridging Pd-Pd sites, which are only present in three-dimensional clusters, are active for the oxygen evolution reaction in Pd6O6. Li-air batteries. The studies show that sub-nm silver clusters have dramatic size-dependent effect on the lowering of the overpotential, charge capacity, morphology of the discharge products, as well as on the morphology of the nm size building blocks of the discharge products. The results suggest that by precise control of the active surface sites on the cathode, the performance of Li-air cells can be significantly improved

Effective capacity of multiple antenna channels: Correlation and keyhole

KAUST Repository

Zhong, Caijun; Ratnarajah, Tharm; Wong, Kaikit; Alouini, Mohamed-Slim

2012-01-01

In this study, the authors derive the effective capacity limits for multiple antenna channels which quantify the maximum achievable rate with consideration of link-layer delay-bound violation probability. Both correlated multiple-input single

Artificial Neural Network In Maximum Power Point Tracking Algorithm Of Photovoltaic Systems

Directory of Open Access Journals (Sweden)

Modestas Pikutis

2014-05-01

Full Text Available Scientists are looking for ways to improve the efficiency of solar cells all the time. The efficiency of solar cells which are available to the general public is up to 20%. Part of the solar energy is unused and a capacity of solar power plant is significantly reduced – if slow controller or controller which cannot stay at maximum power point of solar modules is used. Various algorithms of maximum power point tracking were created, but mostly algorithms are slow or make mistakes. In the literature more and more oftenartificial neural networks (ANN in maximum power point tracking process are mentioned, in order to improve performance of the controller. Self-learner artificial neural network and IncCond algorithm were used for maximum power point tracking in created solar power plant model. The algorithm for control was created. Solar power plant model is implemented in Matlab/Simulink environment.

Inulin-type fructan degradation capacity of Clostridium cluster IV and XIVa butyrate-producing colon bacteria and their associated metabolic outcomes.

Science.gov (United States)

Moens, F; De Vuyst, L

2017-05-30

Four selected butyrate-producing colon bacterial strains belonging to Clostridium cluster IV (Butyricicoccus pullicaecorum DSM 23266 T and Faecalibacterium prausnitzii DSM 17677 T ) and XIVa (Eubacterium hallii DSM 17630 and Eubacterium rectale CIP 105953 T ) were studied as to their capacity to degrade inulin-type fructans and concomitant metabolite production. Cultivation of these strains was performed in bottles and fermentors containing a modified medium for colon bacteria, including acetate, supplemented with either fructose, oligofructose, or inulin as the sole energy source. Inulin-type fructan degradation was not a general characteristic among these strains. B. pullicaecorum DSM 23266 T and E. hallii DSM 17630 could only ferment fructose and did not degrade oligofructose or inulin. E. rectale CIP 105953 T and F. prausnitzii DSM 17677 T fermented fructose and could degrade both oligofructose and inulin. All chain length fractions of oligofructose were degraded simultaneously (both strains) and both long and short chain length fractions of inulin were degraded either simultaneously (E. rectale CIP 105953 T ) or consecutively (F. prausnitzii DSM 17677 T ), indicating an extracellular polymer degradation mechanism. B. pullicaecorum DSM 23266 T and E. hallii DSM 17630 produced high concentrations of butyrate, CO 2 , and H 2 from fructose. E. rectale CIP 105953 T produced lactate, butyrate, CO 2 , and H 2 , from fructose, oligofructose, and inulin, whereas F. prausnitzii DSM 17677 T produced butyrate, formate, CO 2 , and traces of lactate from fructose, oligofructose, and inulin. Based on carbon recovery and theoretical metabolite production calculations, an adapted stoichiometrically balanced metabolic pathway for butyrate, formate, lactate, CO 2 , and H 2 production by members of both Clostridium cluster IV and XIVa butyrate-producing bacteria was constructed.

Maximum Profit Configurations of Commercial Engines

Directory of Open Access Journals (Sweden)

Yiran Chen

2011-06-01

Full Text Available An investigation of commercial engines with finite capacity low- and high-price economic subsystems and a generalized commodity transfer law [n ∝ Δ (P m] in commodity flow processes, in which effects of the price elasticities of supply and demand are introduced, is presented in this paper. Optimal cycle configurations of commercial engines for maximum profit are obtained by applying optimal control theory. In some special cases, the eventual state—market equilibrium—is solely determined by the initial conditions and the inherent characteristics of two subsystems; while the different ways of transfer affect the model in respects of the specific forms of the paths of prices and the instantaneous commodity flow, i.e., the optimal configuration.

Is the Comma cluster a zel'dovich disk

International Nuclear Information System (INIS)

Thompson, L.A.; Gregory, S.A.

1978-01-01

The two-dimensional structure of the Coma cluster is analyzed with the use of galaxies from a wide-area redshift survey. Since redshift observations allow us to sort cluster galaxies from foreground and background galaxies, we can accurately trace the cluster structure to large radii. The following results have been obtained: (1) The center of mass of the Coma cluster is coincident with NGC 4874, the brightest S0 (or cD) galaxy. (2) The cluster has an elliptical shape with axis ratio-0.55 and position angle 67 0 . (3) There is a sharp falloff in the distribution of bright galaxies at a radius ab)/sup 1/2/=rapprox. =3.1. (4) The radial distribution of galaxies contains a slight secondary maximum at a radius (ab) 12 =rapprox. =1 0 .4. The observations are used to show that the cluster may be composed of two components, a central spherical core plus a more widely idspersed flattened disk. We suggest that the observed structure of Coma can be consistently explained using the model of Doroshkevich, Sunyaev, and Zel'kovich which involves the formation of massive protoclusters prior to the epoch of galaxy formation

Bonded Joints with “Nano-Stitches”: Effect of Carbon Nanotubes on Load Capacity and Failure Modes

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Henrique N. P. Oliva

Full Text Available Abstract Carbon nanotubes were employed as adhesive reinforcement/nano-stitches to aluminum bonded joints. The CNT addition to an epoxy adhesive not only lead to an increase on load capacity but it is also the most probable cause of the mixed failure mode (adhesive/cohesive. The damage evolution was described as the stiffness decrease and the failure mixed modes were related to the load capacity. Although the presence of CNT cluster were observed, in small concentrations (< 1.0 wt. %, these clusters acted as crack stoppers and lead to an increase on lap joint shear strength. The addition of 2.0 wt. % carbon nanotubes lead to an increase on load capacity of approximately 116.2 % when the results were compared against the single lap joints without carbon nanotubes.

Collision cascades and sputtering induced by larger cluster ions

International Nuclear Information System (INIS)

Sigmund, P.

1988-01-01

Recent experimental work on larger cluster impact on solid surfaces suggests large deviations from the standard case of additive sputter yields both in the nuclear and electronic stopping regime. The paper concentrates on elastic collision cascades. In addition to very pronounced spike effects, two phenomena are pointed out that are specific to cluster bombardment. Multiple hits of cluster atoms on one and the same target atom may result in recoil atoms that move faster than the maximum recoil speed for monomer bombardment at the same projectile speed. This effect is important when the atomic mass of a beam atom is less than that of a target atom, M 1 2 . In the opposite case, M 1 >> M 2 , collisions between beam particles may accelerate some beam particles and slow down others. Some consequences are mentioned. Remarks on the nuclear stopping power of larger clusters and on electronic sputtering by cluster bombardment conclude the paper. 38 refs., 2 figs

Constraints on H(0) from globular clusters

International Nuclear Information System (INIS)

Vandenberg, D.A.

1988-01-01

On the basis of canonical stellar evolutionary computations, the maximum age of the globular clusters is suggested to be near either 14 Gyr or 18 Gyr, depending on how (O/Fe) varies with (Fe/H) in the cluster stars. The lower estimate requires that H(0) = 65 km/s/Mpc or less, for all Omega(0) = O or greater, if the standard Big-Bang cosmological theory is correct - while the higher age value similarly constrains the Hubble constant to be smaller than 46 km/s/Mpc. Some reduction in the upper limit to cluster ages and a consequent increase in H(0) may be expected if helium diffusion is important in Population II stars; nevertheless, values of H(0) greater than 75 km/s/Mpc still appear to be precluded unless the cosmological constant is nonzero. 51 refs

Bounds on the Capacity of Weakly constrained two-dimensional Codes

DEFF Research Database (Denmark)

Forchhammer, Søren

2002-01-01

Upper and lower bounds are presented for the capacity of weakly constrained two-dimensional codes. The maximum entropy is calculated for two simple models of 2-D codes constraining the probability of neighboring 1s as an example. For given models of the coded data, upper and lower bounds...... on the capacity for 2-D channel models based on occurrences of neighboring 1s are considered....

Evaluation of maximum voided volume in Korean children by use of a 48-h frequency volume chart.

Science.gov (United States)

Kim, Sun-Ouck; Kim, Kyung Do; Kim, Young Sig; Kim, Jun Mo; Moon, Du Geon; Park, Sungchan; Lee, Sang Don; Chung, Jae Min; Cho, Won Yeol

2012-08-01

Study Type - Diagnostic (validating cohort). Level of Evidence 2a. What's known on the subject? and What does the study add? The relationship between the maximum voided volume followed a linear curve. The formula presented, bladder capacity (mL) = 12 ×[age (years) + 11], is thought to be a reasonable one for Korean children. Korean children have a smaller bladder capacity than that reported in previous Western studies. • To develop practical guidelines for the prediction of normal bladder capacity in Korean children measured by a frequency volume chart (FVC), maximum voided volume (MVV) is an important factor in the diagnosis of children with abnormal voiding function. • In all, 298 children, aged 3-13 years, with no history of voiding disorders volunteered for the study. The MVV was determined in 219 subjects by use of a completely recorded FVC. • Linear regression analysis was used to define the exact relationship between age and bladder capacity. An approximate formula related age to bladder capacity as follows: bladder capacity (mL) = 12 ×[age (years) + 11]. • The relationship between the MVV measured by a FVC by age (3-13 years) of Korean children followed a linear curve. • When applied to normal voiding patterns, the formula presented appears to be a reasonable one for Korean children. © 2011 BJU INTERNATIONAL.

Fatigue Feature Extraction Analysis based on a K-Means Clustering Approach

Directory of Open Access Journals (Sweden)

M.F.M. Yunoh

2015-06-01

Full Text Available This paper focuses on clustering analysis using a K-means approach for fatigue feature dataset extraction. The aim of this study is to group the dataset as closely as possible (homogeneity for the scattered dataset. Kurtosis, the wavelet-based energy coefficient and fatigue damage are calculated for all segments after the extraction process using wavelet transform. Kurtosis, the wavelet-based energy coefficient and fatigue damage are used as input data for the K-means clustering approach. K-means clustering calculates the average distance of each group from the centroid and gives the objective function values. Based on the results, maximum values of the objective function can be seen in the two centroid clusters, with a value of 11.58. The minimum objective function value is found at 8.06 for five centroid clusters. It can be seen that the objective function with the lowest value for the number of clusters is equal to five; which is therefore the best cluster for the dataset.

Deployment Strategies and Clustering Protocols Efficiency

Directory of Open Access Journals (Sweden)

Chérif Diallo

2017-06-01

Full Text Available Wireless sensor networks face significant design challenges due to limited computing and storage capacities and, most importantly, dependence on limited battery power. Energy is a critical resource and is often an important issue to the deployment of sensor applications that claim to be omnipresent in the world of future. Thus optimizing the deployment of sensors becomes a major constraint in the design and implementation of a WSN in order to ensure better network operations. In wireless networking, clustering techniques add scalability, reduce the computation complexity of routing protocols, allow data aggregation and then enhance the network performance. The well-known MaxMin clustering algorithm was previously generalized, corrected and validated. Then, in a previous work we have improved MaxMin by proposing a Single- node Cluster Reduction (SNCR mechanism which eliminates single-node clusters and then improve energy efficiency. In this paper, we show that MaxMin, because of its original pathological case, does not support the grid deployment topology, which is frequently used in WSN architectures. The unreliability feature of the wireless links could have negative impacts on Link Quality Indicator (LQI based clustering protocols. So, in the second part of this paper we show how our distributed Link Quality based d- Clustering Protocol (LQI-DCP has good performance in both stable and high unreliable link environments. Finally, performance evaluation results also show that LQI-DCP fully supports the grid deployment topology and is more energy efficient than MaxMin.

Evaluation of lung volumes, vital capacity and respiratory muscle strength after cervical, thoracic and lumbar spinal surgery.

Science.gov (United States)

Oliveira, Marcio Aparecido; Vidotto, Milena Carlos; Nascimento, Oliver Augusto; Almeida, Renato; Santoro, Ilka Lopes; Sperandio, Evandro Fornias; Jardim, José Roberto; Gazzotti, Mariana Rodrigues

2015-01-01

Studies have shown that physiopathological changes to the respiratory system can occur following thoracic and abdominal surgery. Laminectomy is considered to be a peripheral surgical procedure, but it is possible that thoracic spinal surgery exerts a greater influence on lung function. The aim of this study was to evaluate the pulmonary volumes and maximum respiratory pressures of patients undergoing cervical, thoracic or lumbar spinal surgery. Prospective study in a tertiary-level university hospital. Sixty-three patients undergoing laminectomy due to diagnoses of tumors or herniated discs were evaluated. Vital capacity, tidal volume, minute ventilation and maximum respiratory pressures were evaluated preoperatively and on the first and second postoperative days. Possible associations between the respiratory variables and the duration of the operation, surgical diagnosis and smoking status were investigated. Vital capacity and maximum inspiratory pressure presented reductions on the first postoperative day (20.9% and 91.6%, respectively) for thoracic surgery (P = 0.01), and maximum expiratory pressure showed reductions on the first postoperative day in cervical surgery patients (15.3%; P = 0.004). The incidence of pulmonary complications was 3.6%. There were reductions in vital capacity and maximum respiratory pressures during the postoperative period in patients undergoing laminectomy. Surgery in the thoracic region was associated with greater reductions in vital capacity and maximum inspiratory pressure, compared with cervical and lumbar surgery. Thus, surgical manipulation of the thoracic region appears to have more influence on pulmonary function and respiratory muscle action.

Clustered DNA damage induced by proton and heavy ion irradiation

International Nuclear Information System (INIS)

Davidkova, M.; Pachnerova Brabcova, K; Stepan, V.; Vysin, L.; Sihver, L.; Incerti, S.

2014-01-01

Ionizing radiation induces in DNA strand breaks, damaged bases and modified sugars, which accumulate with increasing density of ionizations in charged particle tracks. Compared to isolated DNA damage sites, the biological toxicity of damage clusters can be for living cells more severe. We investigated the clustered DNA damage induced by protons (30 MeV) and high LET radiation (C 290 MeV/u and Fe 500 MeV/u) in pBR322 plasmid DNA. To distinguish between direct and indirect pathways of radiation damage, the plasmid was irradiated in pure water or in aqueous solution of one of the three scavengers (coumarin-3-carboxylic acid, dimethylsulfoxide, and glycylglycine). The goal of the contribution is the analysis of determined types of DNA damage in dependence on radiation quality and related contribution of direct and indirect radiation effects. The yield of double strand breaks (DSB) induced in the DNA plasmid-scavenger system by heavy ion radiation was found to decrease with increasing scavenging capacity due to reaction with hydroxyl radical, linearly with high correlation coefficients. The yield of non-DSB clusters was found to occur twice as much as the DSB. Their decrease with increasing scavenging capacity had lower linear correlation coefficients. This indicates that the yield of non-DSB clusters depends on more factors, which are likely connected to the chemical properties of individual scavengers. (authors)

Chain Networks as a Leverage for Innovation Capacity: The Case of Food SMEs

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Bianka Kühne

2011-02-01

Full Text Available  Nowadays, innovation is no longer limited to the individual firm but involves increasingly the chain network in which the firm is embedded. The chain network is considered as the place where the internal and external resources of a firm are combined and transformed, leading to innovation capacity. In the increasingly globalizing market, innovation is an important strategic tool for small and medium sized enterprises (SMEs to achieve competitive advantage. However, SMEs are often confronted with barriers for developing and introducing innovations, such as the lack of economies of scale. Our paper investigates how the chain network is contributing to the enhancement of the innovation capacity and which chain network characteristics are crucial in this process. In contrast to previous studies at chain network level, in our research specific chain networks are investigated and compared to each other. Hence, data collection took place at different chain network levels, being the supplier, the food manufacturer and the customer, working together and consequently belonging to one specific and unique chain network.The analysis of innovation capacity at the chain network level is realized by means of cluster analysis. This results in a three-cluster solution dividing the sample into Non-innovator chain networks, Customer-driven innovator chain networks and food manufacturer-supplier-driven innovator chain networks. Next, the influence of the chain network on the innovation capacity is examined. Thereby, the three achieved clusters differ significantly related to certain chain network characteristics. The following characteristics form an important leverage for the innovation capacity: firm size, profitability and business growth of the chain network members, as well as higher dependency, and lower levels of integration, rewarding power, social satisfaction and collaboration. The distinction of Customer-driven and food manufacturer

Dirichlet Process Parsimonious Mixtures for clustering

OpenAIRE

Chamroukhi, Faicel; Bartcus, Marius; Glotin, Hervé

2015-01-01

The parsimonious Gaussian mixture models, which exploit an eigenvalue decomposition of the group covariance matrices of the Gaussian mixture, have shown their success in particular in cluster analysis. Their estimation is in general performed by maximum likelihood estimation and has also been considered from a parametric Bayesian prospective. We propose new Dirichlet Process Parsimonious mixtures (DPPM) which represent a Bayesian nonparametric formulation of these parsimonious Gaussian mixtur...

Secrecy Capacity Analysis over α−μ Fading Channels

KAUST Repository

Lei, Hongjiang

2017-02-15

In this work, we study the secrecy capacity of the classic Wyner’s model over the α − μ fading channels, where α and μ specify the nonlinearity and clustering of fading channels, respectively. The average secrecy capacity (ASC) is derived in closed-form by using the extended generalized bivariate Fox’s Hfunction (EGBFHF). Moreover, the asymptotic analysis of ASC in high signal-to-noise ratio (SNR) regime is conducted. The asymptotic results unveil that the ASC follows the scaling law of Θ(ln p), where p stands for the ratio between the average powers of main channels and eavesdropping channels. Moreover, the ASC can be enhanced by increasing the transmit SNR, while there exists a ceiling of ASC as the SNRs at both sides are improved simultaneously. The accuracy of the analytical results is validated by Monte-Carlo simulations. The numerical results show that rigorous fading channels are beneficial to the secrecy performance, that is, serious nonlinearity (small α) and sparse clustering (small μ) will lead to the improvement of ASC.

Secrecy Capacity Analysis over α−μ Fading Channels

KAUST Repository

Lei, Hongjiang; Ansari, Imran Shafique; Pan, Gaofeng; Alomair, Basel; Alouini, Mohamed-Slim

2017-01-01

In this work, we study the secrecy capacity of the classic Wyner’s model over the α − μ fading channels, where α and μ specify the nonlinearity and clustering of fading channels, respectively. The average secrecy capacity (ASC) is derived in closed-form by using the extended generalized bivariate Fox’s Hfunction (EGBFHF). Moreover, the asymptotic analysis of ASC in high signal-to-noise ratio (SNR) regime is conducted. The asymptotic results unveil that the ASC follows the scaling law of Θ(ln p), where p stands for the ratio between the average powers of main channels and eavesdropping channels. Moreover, the ASC can be enhanced by increasing the transmit SNR, while there exists a ceiling of ASC as the SNRs at both sides are improved simultaneously. The accuracy of the analytical results is validated by Monte-Carlo simulations. The numerical results show that rigorous fading channels are beneficial to the secrecy performance, that is, serious nonlinearity (small α) and sparse clustering (small μ) will lead to the improvement of ASC.

Sodium fire aerosol loading capacity of several sand and gravel filters

International Nuclear Information System (INIS)

Barreca, J.R.; McCormack, J.D.

1980-04-01

Improved specific loading capacity for sodium fire aerosols was the objective of a sand and gravel test series. The aerosol capacity and related differential pressure of eight aggregate filters is presented. A maximum specific aerosol capacity, for dry aerosol, of 2.4 kg (Na) m -2 was obtained. This filter was loaded to a final differential pressure of 2.6 kPa. The average superficial face velocity was 0.5 cm/s and the average efficiency was 99.8%. The test results indicate that filter capacity increases with aerosol moisture content and with decreasing superficial velocity

Optimal wavelength band clustering for multispectral iris recognition.

Science.gov (United States)

Gong, Yazhuo; Zhang, David; Shi, Pengfei; Yan, Jingqi

2012-07-01

This work explores the possibility of clustering spectral wavelengths based on the maximum dissimilarity of iris textures. The eventual goal is to determine how many bands of spectral wavelengths will be enough for iris multispectral fusion and to find these bands that will provide higher performance of iris multispectral recognition. A multispectral acquisition system was first designed for imaging the iris at narrow spectral bands in the range of 420 to 940 nm. Next, a set of 60 human iris images that correspond to the right and left eyes of 30 different subjects were acquired for an analysis. Finally, we determined that 3 clusters were enough to represent the 10 feature bands of spectral wavelengths using the agglomerative clustering based on two-dimensional principal component analysis. The experimental results suggest (1) the number, center, and composition of clusters of spectral wavelengths and (2) the higher performance of iris multispectral recognition based on a three wavelengths-bands fusion.

A Lagrangian Analysis of Cold Cloud Clusters and Their Life Cycles With Satellite Observations

Science.gov (United States)

Esmaili, Rebekah Bradley; Tian, Yudong; Vila, Daniel Alejandro; Kim, Kyu-Myong

2016-01-01

Cloud movement and evolution signify the complex water and energy transport in the atmosphere-ocean-land system. Detecting, clustering, and tracking clouds as semi coherent cluster objects enables study of their evolution which can complement climate model simulations and enhance satellite retrieval algorithms, where there are large gaps between overpasses. Using an area-overlap cluster tracking algorithm, in this study we examine the trajectories, horizontal extent, and brightness temperature variations of millions of individual cloud clusters over their lifespan, from infrared satellite observations at 30-minute, 4-km resolution, for a period of 11 years. We found that the majority of cold clouds were both small and short-lived and that their frequency and location are influenced by El Nino. More importantly, this large sample of individually tracked clouds shows their horizontal size and temperature evolution. Longer lived clusters tended to achieve their temperature and size maturity milestones at different times, while these stages often occurred simultaneously in shorter lived clusters. On average, clusters with this lag also exhibited a greater rainfall contribution than those where minimum temperature and maximum size stages occurred simultaneously. Furthermore, by examining the diurnal cycle of cluster development over Africa and the Indian subcontinent, we observed differences in the local timing of the maximum occurrence at different life cycle stages. Over land there was a strong diurnal peak in the afternoon while over the ocean there was a semi-diurnal peak composed of longer-lived clusters in the early morning hours and shorter-lived clusters in the afternoon. Building on regional specific work, this study provides a long-term, high-resolution, and global survey of object-based cloud characteristics.

Molecular dynamic simulation of interaction of low-energy Ar and Xe ions with copper clusters at graphite surface

International Nuclear Information System (INIS)

Kornich, G.V.; Lozovskaya, L.I.; Betts, G.; Zaporozhchenko, V.I.; Faupel, F.

2005-01-01

One conducted molecular and dynamic simulation of sputtering of isolated clusters consisting of 13, 27 and 195 Cu atoms from the (0001) graphite surface by 200 eV energy Ar and Xe ions. It is shown that the factors of reflection of Ar and Xe ions from copper clusters differ from one another insignificantly, though the energy of the reflected Xe ions is essentially lower than that of Ar ions. The values of the factor of cluster sputtering by Xe ions are higher in contrast to sputtering by Ar ions. One identified two mechanisms of cluster sputtering resulting in the maximum of sputtering intensity at the polar angles near the normal one, and in periodicity of maximums within the azimuth distributions of sputtering intensity with 60 deg period [ru

Interstellar Extinction in 20 Open Star Clusters

Science.gov (United States)

Rangwal, Geeta; Yadav, R. K. S.; Durgapal, Alok K.; Bisht, D.

2017-12-01

The interstellar extinction law in 20 open star clusters namely, Berkeley 7, Collinder 69, Hogg 10, NGC 2362, Czernik 43, NGC 6530, NGC 6871, Bochum 10, Haffner 18, IC 4996, NGC 2384, NGC 6193, NGC 6618, NGC 7160, Collinder 232, Haffner 19, NGC 2401, NGC 6231, NGC 6823, and NGC 7380 have been studied in the optical and near-IR wavelength ranges. The difference between maximum and minimum values of E(B - V) indicates the presence of non-uniform extinction in all the clusters except Collinder 69, NGC 2362, and NGC 2384. The colour excess ratios are consistent with a normal extinction law for the clusters NGC 6823, Haffner 18, Haffner 19, NGC 7160, NGC 6193, NGC 2401, NGC 2384, NGC 6871, NGC 7380, Berkeley 7, Collinder 69, and IC 4996. We have found that the differential colour-excess ΔE(B - V), which may be due to the occurrence of dust and gas inside the clusters, decreases with the age of the clusters. A spatial variation of colour excess is found in NGC 6193 in the sense that it decreases from east to west in the cluster region. For the clusters Berkeley 7, NGC 7380, and NGC 6871, a dependence of colour excess E(B - V) with spectral class and luminosity is observed. Eight stars in Collinder 232, four stars in NGC 6530, and one star in NGC 6231 have excess flux in near-IR. This indicates that these stars may have circumstellar material around them.

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). )

The range of variation of the mass of the most massive star in stellar clusters derived from 35 million Monte Carlo simulations

International Nuclear Information System (INIS)

Popescu, Bogdan; Hanson, M. M.

2014-01-01

A growing fraction of simple stellar population models, in an aim to create more realistic simulations capable of including stochastic variation in their outputs, begin their simulations with a distribution of discrete stars following a power-law function of masses. Careful attention is needed to create a correctly sampled initial mass function (IMF), and here we provide a solid mathematical method, called MASSCLEAN IMF Sampling, for doing so. We use our method to perform 10 million MASSCLEAN Monte Carlo stellar cluster simulations to determine the most massive star in a mass distribution as a function of the total mass of the cluster. We find that a maximum mass range is predicted, not a single maximum mass. This range is (1) dependent on the total mass of the cluster and (2) independent of an upper stellar mass limit, M limit , for unsaturated clusters and emerges naturally from our IMF sampling method. We then turn our analysis around, starting with our new database of 25 million simulated clusters, to constrain the highest mass star from the observed integrated colors of a sample of 40 low-mass Large Magellanic Cloud stellar clusters of known age and mass. Finally, we present an analytical description of the maximum mass range of the most massive star as a function of the cluster's total mass and present a new M max -M cluster relation.

Deuterium cluster model for low energy nuclear reactions (LENR)

Science.gov (United States)

Miley, George; Hora, Heinrich

2007-11-01

For studying the possible reactions of high density deuterons on the background of a degenerate electron gas, a summary of experimental observations resulted in the possibility of reactions in pm distance and more than ksec duration similar to the K-shell electron capture [1]. The essential reason was the screening of the deuterons by a factor of 14 based on the observations. Using the bosonic properties for a cluster formation of the deuterons and a model of compound nuclear reactions [2], the measured distribution of the resulting nuclei may be explained as known from the Maruhn-Greiner theory for fission. The local maximum of the distribution at the main minimum indicates the excited states of the compound nuclei during their intermediary state. This measured local maximum may be an independent proof for the deuteron clusters at LENR. [1] H. Hora, G.H. Miley et al. Physics Letters A175, 138 (1993) [2] H. Hora and G.H. Miley, APS March Meeting 2007, Program p. 116

Unbiased structural search of small copper clusters within DFT

Energy Technology Data Exchange (ETDEWEB)

Cogollo-Olivo, Beatriz H., E-mail: bcogolloo@unicartagena.edu.co [Maestría en Ciencias Físicas, Universidad de Cartagena, 130001 Cartagena de Indias, Bolívar (Colombia); Seriani, Nicola, E-mail: nseriani@ictp.it [Condensed Matter and Statistical Physics Section, The Abdus Salam ICTP, Strada Costiera 11, 34151 Trieste (Italy); Montoya, Javier A., E-mail: jmontoyam@unicartagena.edu.co [Instituto de Matemáticas Aplicadas, Universidad de Cartagena, 130001 Cartagena de Indias, Bolívar (Colombia); Associates Program, The Abdus Salam ICTP, Strada Costiera 11, 34151 Trieste (Italy)

2015-11-05

Highlights: • We have been able to identify novel metastable structures for small Cu clusters. • We have shown that a linear structure reported for Cu{sub 3} is actually a local maximum. • Some of the structures reported in literature are actually unstable within DFT. • Some of the isomer structures found shows the limits of educated guesses. - Abstract: The atomic structure of small Cu clusters with 3–6 atoms has been investigated by density functional theory and random search algorithm. New metastable structures have been found that lie merely tens of meV/atom above the corresponding ground state, and could therefore be present at thermodynamic equilibrium at room temperature or slightly above. Moreover, we show that the previously proposed linear configuration for Cu{sub 3} is in fact a local maximum of the energy. Finally, we argue that the random search algorithm also provides qualitative information about the attraction basin of each structure in the energy landscape.

Unbiased structural search of small copper clusters within DFT

International Nuclear Information System (INIS)

Cogollo-Olivo, Beatriz H.; Seriani, Nicola; Montoya, Javier A.

2015-01-01

Highlights: • We have been able to identify novel metastable structures for small Cu clusters. • We have shown that a linear structure reported for Cu_3 is actually a local maximum. • Some of the structures reported in literature are actually unstable within DFT. • Some of the isomer structures found shows the limits of educated guesses. - Abstract: The atomic structure of small Cu clusters with 3–6 atoms has been investigated by density functional theory and random search algorithm. New metastable structures have been found that lie merely tens of meV/atom above the corresponding ground state, and could therefore be present at thermodynamic equilibrium at room temperature or slightly above. Moreover, we show that the previously proposed linear configuration for Cu_3 is in fact a local maximum of the energy. Finally, we argue that the random search algorithm also provides qualitative information about the attraction basin of each structure in the energy landscape.

Anharmonic effects in the quantum cluster equilibrium method

Science.gov (United States)

von Domaros, Michael; Perlt, Eva

2017-03-01

The well-established quantum cluster equilibrium (QCE) model provides a statistical thermodynamic framework to apply high-level ab initio calculations of finite cluster structures to macroscopic liquid phases using the partition function. So far, the harmonic approximation has been applied throughout the calculations. In this article, we apply an important correction in the evaluation of the one-particle partition function and account for anharmonicity. Therefore, we implemented an analytical approximation to the Morse partition function and the derivatives of its logarithm with respect to temperature, which are required for the evaluation of thermodynamic quantities. This anharmonic QCE approach has been applied to liquid hydrogen chloride and cluster distributions, and the molar volume, the volumetric thermal expansion coefficient, and the isobaric heat capacity have been calculated. An improved description for all properties is observed if anharmonic effects are considered.

Capacity of weakly (d,k)-constrained sequences

NARCIS (Netherlands)

Schouhamer Immink, K.A.; Janssen, A.J.E.M.

2000-01-01

In the presentation we find an analytic expression for the maximum of the normalized entropy - ¿ieT pi In pi / ¿ieT ipi where the set T is the disjoint union of sets Sn of positive integers that are assigned probabilities Pn, ¿n Pn = 1. This result is applied to the computation of the capacity of

Rocky Mountain Regional CO{sub 2} Storage Capacity and Significance

Energy Technology Data Exchange (ETDEWEB)

Laes, Denise; Eisinger, Chris; Esser, Richard; Morgan, Craig; Rauzi, Steve; Scholle, Dana; Matthews, Vince; McPherson, Brian

2013-08-30

The purpose of this study includes extensive characterization of the most promising geologic CO{sub 2} storage formations on the Colorado Plateau, including estimates of maximum possible storage capacity. The primary targets of characterization and capacity analysis include the Cretaceous Dakota Formation, the Jurassic Entrada Formation and the Permian Weber Formation and their equivalents in the Colorado Plateau region. The total CO{sub 2} capacity estimates for the deep saline formations of the Colorado Plateau region range between 9.8 metric GT and 143 metric GT, depending on assumed storage efficiency, formations included, and other factors.

Uncertainty of a detected spatial cluster in 1D: quantification and visualization

KAUST Repository

Lee, Junho; Gangnon, Ronald E.; Zhu, Jun; Liang, Jingjing

2017-01-01

Spatial cluster detection is an important problem in a variety of scientific disciplines such as environmental sciences, epidemiology and sociology. However, there appears to be very limited statistical methodology for quantifying the uncertainty of a detected cluster. In this paper, we develop a new method for the quantification and visualization of uncertainty associated with a detected cluster. Our approach is defining a confidence set for the true cluster and visualizing the confidence set, based on the maximum likelihood, in time or in one-dimensional space. We evaluate the pivotal property of the statistic used to construct the confidence set and the coverage rate for the true cluster via empirical distributions. For illustration, our methodology is applied to both simulated data and an Alaska boreal forest dataset. Copyright © 2017 John Wiley & Sons, Ltd.

Uncertainty of a detected spatial cluster in 1D: quantification and visualization

KAUST Repository

Lee, Junho

2017-10-19

Spatial cluster detection is an important problem in a variety of scientific disciplines such as environmental sciences, epidemiology and sociology. However, there appears to be very limited statistical methodology for quantifying the uncertainty of a detected cluster. In this paper, we develop a new method for the quantification and visualization of uncertainty associated with a detected cluster. Our approach is defining a confidence set for the true cluster and visualizing the confidence set, based on the maximum likelihood, in time or in one-dimensional space. We evaluate the pivotal property of the statistic used to construct the confidence set and the coverage rate for the true cluster via empirical distributions. For illustration, our methodology is applied to both simulated data and an Alaska boreal forest dataset. Copyright © 2017 John Wiley & Sons, Ltd.

Dimensional scale effects on surface enhanced Raman scattering efficiency of self-assembled silver nanoparticle clusters

International Nuclear Information System (INIS)

Fasolato, C.; Domenici, F.; De Angelis, L.; Luongo, F.; Postorino, P.; Sennato, S.; Mura, F.; Costantini, F.; Bordi, F.

2014-01-01

A study of the Surface Enhanced Raman Scattering (SERS) from micrometric metallic nanoparticle aggregates is presented. The sample is obtained from the self-assembly on glass slides of micro-clusters of silver nanoparticles (60 and 100 nm diameter), functionalized with the organic molecule 4-aminothiophenol in water solution. For nanoparticle clusters at the micron scale, a maximum enhancement factor of 10 9 is estimated from the SERS over the Raman intensity ratio normalized to the single molecule contribution. Atomic force microscopy, correlated to spatially resolved Raman measurements, allows highlighting the connection between morphology and efficiency of the plasmonic system. The correlation between geometric features and SERS response of the metallic structures reveals a linear trend of the cluster maximum scattered intensity as a function of the surface area of the aggregate. On given clusters, the intensity turns out to be also influenced by the number of stacking planes of the aggregate, thus suggesting a plasmonic waveguide effect. The linear dependence results weakened for the largest area clusters, suggesting 30 μm 2 as the upper limit for exploiting the coherence over large scale of the plasmonic response.

Effective capacity of multiple antenna channels: Correlation and keyhole

KAUST Repository

Zhong, Caijun

2012-01-01

In this study, the authors derive the effective capacity limits for multiple antenna channels which quantify the maximum achievable rate with consideration of link-layer delay-bound violation probability. Both correlated multiple-input single-output and multiple-input multiple-output keyhole channels are studied. Based on the closed-form exact expressions for the effective capacity of both channels, the authors look into the asymptotic high and low signal-to-noise ratio regimes, and derive simple expressions to gain more insights. The impact of spatial correlation on effective capacity is also characterised with the aid of a majorisation theory result. It is revealed that antenna correlation reduces the effective capacity of the channels and a stringent quality-of-service requirement causes a severe reduction in the effective capacity but can be alleviated by increasing the number of antennas. © 2012 The Institution of Engineering and Technology.

Dark energy and key physical parameters of clusters of galaxies

Science.gov (United States)

Bisnovatyi-Kogan, G. S.; Chernin, A. D.

2012-04-01

We study physics of clusters of galaxies embedded in the cosmic dark energy background. Under the assumption that dark energy is described by the cosmological constant, we show that the dynamical effects of dark energy are strong in clusters like the Virgo cluster. Specifically, the key physical parameters of the dark mater halos in clusters are determined by dark energy: (1) the halo cut-off radius is practically, if not exactly, equal to the zero-gravity radius at which the dark matter gravity is balanced by the dark energy antigravity; (2) the halo averaged density is equal to two densities of dark energy; (3) the halo edge (cut-off) density is the dark energy density with a numerical factor of the unity order slightly depending on the halo profile. The cluster gravitational potential well in which the particles of the dark halo (as well as galaxies and intracluster plasma) move is strongly affected by dark energy: the maximum of the potential is located at the zero-gravity radius of the cluster.

Phosphorus retention capacity of sediments in Mandovi estuary (Goa)

Digital Repository Service at National Institute of Oceanography (India)

Rajagopal, M.D.; Reddy, C

Experiments carried out under controlled conditions to study P retention capacity of sediments indicate that the processes of adsorption and desorption of P are pH dependent. Adsorption of P is maximum (58-99%) at pH 4. Both the exchangeable P...

Nucleation from a cluster of inclusions, leading to void coalescense

DEFF Research Database (Denmark)

Tvergaard, Viggo

2017-01-01

A cell model analysis is used to study the nucleation and subsequent growth of voids from a non-uniform distribution of inclusions in a ductile material. Nucleation is modeled as either stress controlled or strain controlled. The special clusters considered consist of a number of uniformly spaced...... inclusions located along a plane perpendicular to the maximum principal tensile stress. A plane strain approximation is used, where the inclusions are parallel cylinders perpendicular to the plane. Clusters with different numbers of inclusions are compared with the nucleation and growth from a single...... inclusion, such that the total initial volume of the inclusions is the same for the clusters and the single inclusion. After nucleation, local void coalescence inside the clusters is accounted for, since this makes it possible to compare the rate of growth of the single larger void that results from...

Low-SNR Capacity of MIMO Optical Intensity Channels

KAUST Repository

Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

2017-01-01

The capacity of the multiple-input multiple-output (MIMO) optical intensity channel is studied, under both average and peak intensity constraints. We focus on low SNR, which can be modeled as the scenario where both constraints proportionally vanish, or where the peak constraint is held constant while the average constraint vanishes. A capacity upper bound is derived, and is shown to be tight at low SNR under both scenarios. The capacity achieving input distribution at low SNR is shown to be a maximally-correlated vector-binary input distribution. Consequently, the low-SNR capacity of the channel is characterized. As a byproduct, it is shown that for a channel with peak intensity constraints only, or with peak intensity constraints and individual (per aperture) average intensity constraints, a simple scheme composed of coded on-off keying, spatial repetition, and maximum-ratio combining is optimal at low SNR.

Low-SNR Capacity of MIMO Optical Intensity Channels

KAUST Repository

Chaaban, Anas

2017-09-18

The capacity of the multiple-input multiple-output (MIMO) optical intensity channel is studied, under both average and peak intensity constraints. We focus on low SNR, which can be modeled as the scenario where both constraints proportionally vanish, or where the peak constraint is held constant while the average constraint vanishes. A capacity upper bound is derived, and is shown to be tight at low SNR under both scenarios. The capacity achieving input distribution at low SNR is shown to be a maximally-correlated vector-binary input distribution. Consequently, the low-SNR capacity of the channel is characterized. As a byproduct, it is shown that for a channel with peak intensity constraints only, or with peak intensity constraints and individual (per aperture) average intensity constraints, a simple scheme composed of coded on-off keying, spatial repetition, and maximum-ratio combining is optimal at low SNR.

Adsorption and Formation of Small Na Clusters on Pristine and Double-Vacancy Graphene for Anodes of Na-Ion Batteries.

Science.gov (United States)

Liang, Zhicong; Fan, Xiaofeng; Zheng, Weitao; Singh, David J

2017-05-24

Layered carbon is a likely anode material for Na-ion batteries (NIBs). Graphitic carbon has a low capacity of approximately 35 (mA h)/g due to the formation of NaC 64 . Using first-principles methods including van der Waals interactions, we analyze the adsorption of Na ions and clusters on graphene in the context of anodes. The interaction between Na ions and graphene is found to be weak. Small Na clusters are not stable on the surface of pristine graphene in the electrochemical environment of NIBs. However, we find that Na ions and clusters can be stored effectively on defected graphene that has double vacancies. In addition, the adsorption energy of small Na clusters near a double vacancy is found to decrease with increasing cluster size. With high concentrations of vacancies the capacity of Na on defective graphene is found to be as much as 10-30 times higher than that of graphitic carbon.

Does cluster loading enhance lower body power development in preseason preparation of elite rugby union players?

Science.gov (United States)

Hansen, Keir T; Cronin, John B; Pickering, Stuart L; Newton, Michael J

2011-08-01

The purpose of this study was to ascertain whether cluster training led to improved power training adaptations in the preseason preparation of elite level rugby union players. Eighteen highly trained athletes were divided into 2 training groups, a traditional training (TT, N = 9) group and a cluster training (CT, N = 9) group before undertaking 8 weeks of lower body resistance training. Force-velocity-power profiling in the jump squat movement was undertaken, and maximum strength was assessed in the back squat before and after the training intervention. Two-way analysis of variance and magnitude-based inferences were used to assess changes in maximum strength and force, velocity, and power values pretraining to posttraining. Both TT and CT groups significantly (p benefit of cluster type loading in training prescription for lower body power development.

REDUCTION CAPACITY OF SALTSTONE AND SALTSTONE COMPONENTS

Energy Technology Data Exchange (ETDEWEB)

Roberts, K.; Kaplan, D.

2009-11-30

The duration that saltstone retains its ability to immobilize some key radionuclides, such as technetium (Tc), plutonium (Pu), and neptunium (Np), depends on its capacity to maintain a low redox status (or low oxidation state). The reduction capacity is a measure of the mass of reductants present in the saltstone; the reductants are the active ingredients that immobilize Tc, Pu, and Np. Once reductants are exhausted, the saltstone loses its ability to immobilize these radionuclides. The reduction capacity values reported here are based on the Ce(IV)/Fe(II) system. The Portland cement (198 {micro}eq/g) and especially the fly ash (299 {micro}eq/g) had a measurable amount of reduction capacity, but the blast furnace slag (820 {micro}eq/g) not surprisingly accounted for most of the reduction capacity. The blast furnace slag contains ferrous iron and sulfides which are strong reducing and precipitating species for a large number of solids. Three saltstone samples containing 45% slag or one sample containing 90% slag had essentially the same reduction capacity as pure slag. There appears to be some critical concentration between 10% and 45% slag in the Saltstone formulation that is needed to create the maximum reduction capacity. Values from this work supported those previously reported, namely that the reduction capacity of SRS saltstone is about 820 {micro}eq/g; this value is recommended for estimating the longevity that the Saltstone Disposal Facility will retain its ability to immobilize radionuclides.

Spatial cluster detection using dynamic programming

Directory of Open Access Journals (Sweden)

Sverchkov Yuriy

2012-03-01

Full Text Available Abstract Background The task of spatial cluster detection involves finding spatial regions where some property deviates from the norm or the expected value. In a probabilistic setting this task can be expressed as finding a region where some event is significantly more likely than usual. Spatial cluster detection is of interest in fields such as biosurveillance, mining of astronomical data, military surveillance, and analysis of fMRI images. In almost all such applications we are interested both in the question of whether a cluster exists in the data, and if it exists, we are interested in finding the most accurate characterization of the cluster. Methods We present a general dynamic programming algorithm for grid-based spatial cluster detection. The algorithm can be used for both Bayesian maximum a-posteriori (MAP estimation of the most likely spatial distribution of clusters and Bayesian model averaging over a large space of spatial cluster distributions to compute the posterior probability of an unusual spatial clustering. The algorithm is explained and evaluated in the context of a biosurveillance application, specifically the detection and identification of Influenza outbreaks based on emergency department visits. A relatively simple underlying model is constructed for the purpose of evaluating the algorithm, and the algorithm is evaluated using the model and semi-synthetic test data. Results When compared to baseline methods, tests indicate that the new algorithm can improve MAP estimates under certain conditions: the greedy algorithm we compared our method to was found to be more sensitive to smaller outbreaks, while as the size of the outbreaks increases, in terms of area affected and proportion of individuals affected, our method overtakes the greedy algorithm in spatial precision and recall. The new algorithm performs on-par with baseline methods in the task of Bayesian model averaging. Conclusions We conclude that the dynamic

Palladium clusters deposited on the heterogeneous substrates

Energy Technology Data Exchange (ETDEWEB)

Wang, Kun, E-mail: cqdxwk@126.com [College of Power Engineering, Chongqing University, Chongqing 400044 (China); Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Ministry of Education of PRC, Chongqing 400044 (China); Liu, Juanfang, E-mail: juanfang@cqu.edu.cn [College of Power Engineering, Chongqing University, Chongqing 400044 (China); Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Ministry of Education of PRC, Chongqing 400044 (China); Chen, Qinghua, E-mail: qhchen@cqu.edu.cn [College of Power Engineering, Chongqing University, Chongqing 400044 (China); Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Ministry of Education of PRC, Chongqing 400044 (China)

2016-07-15

Graphical abstract: The site-exchange between the substrate and cluster atoms can result in the formation of the surface alloys and the reconstruction of the cluster structure before the collision system approaching the thermal equilibrium. The deposited cluster adjusted the atom arrangement as possibly as to match the substrate lattice arrangement from bottom to up. The structural reconstruction is accompanied by the system potential energy minimization. - Highlights: • The deposition process can divide explicitly into three stages: adsorption, collision, relaxation. • The local melt does not emerge inside the substrate during the deposition process. • Surface alloys are formed by the site-exchange between the cluster and substrate atoms. • The cluster reconstructs the atom arrangement following as the substrate lattice arrangement from bottom to up. • The structural reconstruction ability and scope depend on the cluster size and incident energy. - Abstract: To improve the performance of the Pd composite membrane prepared by the cold spraying technology, it is extremely essential to give insights into the deposition process of the cluster and the heterogeneous deposition of the big Pd cluster at the different incident velocities on the atomic level. The deposition behavior, morphologies, energetic and interfacial configuration were examined by the molecular dynamic simulation and characterized by the cluster flattening ratio, the substrate maximum local temperature, the atom-embedded layer number and the surface-alloy formation. According to the morphology evolution, three deposition stages and the corresponding structural and energy evolution were clearly identified. The cluster deformation and penetrating depth increased with the enhancement of the incident velocity, but the increase degree also depended on the substrate hardness. The interfacial interaction between the cluster and the substrate can be improved by the higher substrate local temperature

Preparation and characterization of magnetic polymer nanospheres with high protein binding capacity

International Nuclear Information System (INIS)

Liu Xianqiao; Guan Yueping; Liu Huizhou; Ma Zhiya; Yang Yu; Wu Xiaobing

2005-01-01

A novel magnetic support with high protein binding capacity was prepared by mini-emulsion polymerization. The magnetic poly(methacrylate-divinylbenzene) nanospheres prepared are 390 nm in diameter with narrow size distribution and star-like external morphology which leads to a large increase in specific surface area. Experimental results indicate that the maximum protein binding capacity is 316 mg bovine hemoglobin (BHb)/g support

Disease clusters, exact distributions of maxima, and P-values.

Science.gov (United States)

Grimson, R C

1993-10-01

This paper presents combinatorial (exact) methods that are useful in the analysis of disease cluster data obtained from small environments, such as buildings and neighbourhoods. Maxwell-Boltzmann and Fermi-Dirac occupancy models are compared in terms of appropriateness of representation of disease incidence patterns (space and/or time) in these environments. The methods are illustrated by a statistical analysis of the incidence pattern of bone fractures in a setting wherein fracture clustering was alleged to be occurring. One of the methodological results derived in this paper is the exact distribution of the maximum cell frequency in occupancy models.

Cosmological Constraints From SDSS MaxBCG Cluster Abundances

International Nuclear Information System (INIS)

Rozo, Eduardo; Wechsler, Risa H.; KICP, Chicago; Koester, Benjamin P.; McKay, Timothy A.; Evrard, August E.; Johnston, David; Sheldon, Erin S.; Annis, James; Frieman, Joshua A.

2007-01-01

We perform a maximum likelihood analysis of the cluster abundance measured in the SDSS using the maxBCG cluster finding algorithm. Our analysis is aimed at constraining the power spectrum normalization σ 8 , and assumes flat cosmologies with a scale invariant spectrum, massless neutrinos, and CMB and supernova priors (Omega) m h 2 = 0.128 ± 0.01 and h = 0.72 ± 0.05 respectively. Following the method described in the companion paper Rozo et al. (2007), we derive σ 8 = 0.92 ± 0.10 (1σ) after marginalizing over all major systematic uncertainties. We place strong lower limits on the normalization, σ 8 > 0.76 (95% CL) (> 0.68 at 99% CL). We also find that our analysis favors relatively low values for the slope of the Halo Occupation Distribution (HOD), α = 0.83 ± 0.06. The uncertainties of these determinations will substantially improve upon completion of an ongoing campaign to estimate dynamical, weak lensing, and X-ray cluster masses in the SDSS maxBCG cluster sample

The range of variation of the mass of the most massive star in stellar clusters derived from 35 million Monte Carlo simulations

Energy Technology Data Exchange (ETDEWEB)

Popescu, Bogdan; Hanson, M. M., E-mail: bogdan.popescu@uc.edu, E-mail: margaret.hanson@uc.edu [Department of Physics, University of Cincinnati, P.O. Box 210011, Cincinnati, OH 45221-0011 (United States)

2014-01-01

A growing fraction of simple stellar population models, in an aim to create more realistic simulations capable of including stochastic variation in their outputs, begin their simulations with a distribution of discrete stars following a power-law function of masses. Careful attention is needed to create a correctly sampled initial mass function (IMF), and here we provide a solid mathematical method, called MASSCLEAN IMF Sampling, for doing so. We use our method to perform 10 million MASSCLEAN Monte Carlo stellar cluster simulations to determine the most massive star in a mass distribution as a function of the total mass of the cluster. We find that a maximum mass range is predicted, not a single maximum mass. This range is (1) dependent on the total mass of the cluster and (2) independent of an upper stellar mass limit, M{sub limit} , for unsaturated clusters and emerges naturally from our IMF sampling method. We then turn our analysis around, starting with our new database of 25 million simulated clusters, to constrain the highest mass star from the observed integrated colors of a sample of 40 low-mass Large Magellanic Cloud stellar clusters of known age and mass. Finally, we present an analytical description of the maximum mass range of the most massive star as a function of the cluster's total mass and present a new M{sub max} -M{sub cluster} relation.

Clustering of two genes putatively involved in cyanate detoxification evolved recently and independently in multiple fungal lineages

Science.gov (United States)

Fungi that have the enzymes cyanase and carbonic anhydrase show a limited capacity to detoxify cyanate, a fungicide employed by both plants and humans. Here, we describe a novel two-gene cluster that comprises duplicated cyanase and carbonic anhydrase copies, which we name the CCA gene cluster, trac...

Seismic fragility capacity of equipment--horizontal shaft pump test

International Nuclear Information System (INIS)

Iijima, T.; Abe, H.; Suzuki, K.

2005-01-01

The current seismic fragility capacity of horizontal shaft pump is 1.6 x 9.8 m/s 2 (1.6 g), which was decided from previous vibration tests and we believe that it must have sufficient margin. The purpose of fragility capacity test is to obtain realistic seismic fragility capacity of horizontal shaft pump by vibration tests. Reactor Building Closed Cooling Water (RCW) Pump was tested as a typical horizontal shaft pump, and then bearings and liner rings were tested as important parts to evaluate critical acceleration and dispersion. Regarding RCW pump test, no damage was found, though maximum input acceleration level was 6 x 9.8 m/s 2 (6 g). Some kinds of bearings and liner rings were tested on the element test. Input load was based on seismic motion which was same with the RCW pump test, and maximum load was equivalent to over 20 times of design seismic acceleration. There was not significant damage that caused emergency stop of pump but degradation of surface roughness was found on some kinds of bearings. It would cause reduction of pump life, but such damage on bearings occurred under large seismic load condition that was equivalent to over 10 to 20 g force. Test results show that realistic fragility capacity of horizontal shaft pump would be at least four times as higher as current value which has been used for our seismic PSA. (authors)

Exogenously applied abscisic acid to Yan73 (V. vinifera) grapes enhances phenolic content and antioxidant capacity of its wine.

Science.gov (United States)

Xi, Zhu-Mei; Meng, Jiang-Fei; Huo, Shan-Shan; Luan, Li-Ying; Ma, Li-Na; Zhang, Zhen-Wen

2013-06-01

Yan73 is a 'teinturier' red wine variety cultivated in China and widely used in winemaking to strengthen red wine colour. The objective of this study was to evaluate the effect of exogenous abscisic acid (ABA) applied to the grapevine cluster on the antioxidant capacity and phenolic content of the wine made from Yan73. Two hundred mg/l ABA was applied on Yan73 grapevine cluster during veraison. As they mature, these ABA-treated and untreated grape berries were transformed into wines, respectively, and the phenolic content and antioxidant capacity of these wines were compared. The results showed that phenolic content (total phenolics, tannins, flavonoids and anthocyanins) and antioxidant capacity were higher in the wine produced with ABA-treated Yan73 grapes than those in the wine from untreated grapes. Compared to Cabernet Sauvignon wine, Yan73 wine had higher phenolic content and stronger antioxidant capacity. These strongly suggest that exogenously applied ABA to Yan73 grapes can enhance phenolic content and antioxidant capacity of its wine, and Yan73 wine has the higher utilization value and potential for development.

Assessment of the climatic potential for tourism in Iran through biometeorology clustering

Science.gov (United States)

Roshan, Gholamreza; Yousefi, Robabe; Błażejczyk, Krzysztof

2017-10-01

This study presents a spatiotemporal analysis of bioclimatic comfort conditions for Iran using mean daily meteorological data from 1995 to 2014, analyzed through Physiological Equivalent Temperature (PET) index and Universal Thermal Climate Index (UTCI) indices, and bioclimatic clustering. The results of this study demonstrate that due to the climate variability across Iran during the year, there is at any point in time a location with climatic condition suitable for tourism. Mean values demonstrate maxima in bioclimatic comfort indices for the country in late winter and spring and minima for summer. Seven statistically significant clusters in bioclimatic indices were identified. Comparing these with clustering performed on PET and UTCI, the maximum overlaps between the two indices. In the following, the outputs of this research showed that most appropriate bioclimatic clustering for Iran includes seven clusters. These clustering locations according to climatic suitability for tourism provide a valuable contribution to tourism management in the country, particularly through marketing destinations to maximize tourist flow.

Assessment of the climatic potential for tourism in Iran through biometeorology clustering.

Science.gov (United States)

Roshan, Gholamreza; Yousefi, Robabe; Błażejczyk, Krzysztof

2018-04-01

This study presents a spatiotemporal analysis of bioclimatic comfort conditions for Iran using mean daily meteorological data from 1995 to 2014, analyzed through Physiological Equivalent Temperature (PET) index and Universal Thermal Climate Index (UTCI) indices, and bioclimatic clustering. The results of this study demonstrate that due to the climate variability across Iran during the year, there is at any point in time a location with climatic condition suitable for tourism. Mean values demonstrate maxima in bioclimatic comfort indices for the country in late winter and spring and minima for summer. Seven statistically significant clusters in bioclimatic indices were identified. Comparing these with clustering performed on PET and UTCI, the maximum overlaps between the two indices. In the following, the outputs of this research showed that most appropriate bioclimatic clustering for Iran includes seven clusters. These clustering locations according to climatic suitability for tourism provide a valuable contribution to tourism management in the country, particularly through marketing destinations to maximize tourist flow.

The system capacity view of aging and longevity

Institute of Scientific and Technical Information of China (English)

Jing-Dong J.Han; Lei Hou; Na Sun; Chi Xu; Joseph McDermott; Dan Wang

2017-01-01

Background:Aging is a complex systems level problem that needs a systems level solution.However,system models of aging and longevity,although urgently needed,are still lacking,largely due to the paucity of conceptual frameworks for modeling such a complex process.Results:We propose that aging can be viewed as a decline in system capacity,defined as the maximum level of output that a system produces to fulfill demands.Classical aging hallmarks and anti-aging strategies can be well-aligned to system capacity.Genetic variants responsible for lifespan variation across individuals or species can also be explained by their roles in system capacity.We further propose promising directions to develop systems approaches to modulate system capacity and thus extend both healthspan and lifespan.Conclusions:The system capacity model of aging provides an opportunity to examine aging at the systems level.This model predicts that the extent to which aging can be modulated is normally limited by the upper bound of the system capacity of a species.Within such a boundary,aging can be delayed by moderately increasing an individual's system capacity.Beyond such a boundary,increasing the upper bound is required,which is not unrealistic given the unlimited potential of regenerative medicine in the future,but it requires increasing the capacity of the whole system instead of only part of it.

Modelling of carrying capacity in National Park - Fruška Gora (Serbia case study

Directory of Open Access Journals (Sweden)

Vujko Aleksandra

2017-03-01

Full Text Available Negative effects of tourism development in a destination are usually the consequence of the high concentration of tourists, accommodation facilities and the activities that are practiced in a relatively restricted area. One of the most important measures to protect the areas is to calculate the maximum number of tourists that can simultaneously reside in a region, i.e. the determination of the carrying capacity. This paper outlines a method for determining carrying capacity based on zoning of environmental resources and zoning within a region. The paper argues for a return to the idea of identifying maximum appropriate number of users. The main hypothesis of the paper is based on the statement that the development of tourism in Fruška Gora (Mountain National Park in Northern Serbia must be in accordance with the basic principles of sustainability, including the determination of carrying capacity. The main research goal was to show the opinion of local residents about the uncontrolled development of tourism, and to determine the carrying capacity in four sports and recreational zones of the mountain. The carrying capacity of the area is calculated by Lavery and Stanev formulas.

30 CFR 75.601-3 - Short circuit protection; dual element fuses; current ratings; maximum values.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit protection; dual element fuses... Trailing Cables § 75.601-3 Short circuit protection; dual element fuses; current ratings; maximum values. Dual element fuses having adequate current-interrupting capacity shall meet the requirements for short...

Relationship between maximum dynamic force of inferior members and body balance in strength training apprentices

Directory of Open Access Journals (Sweden)

Ariane Martins

2010-08-01

Full Text Available The relationship between force and balance show controversy results and has directimplications in exercise prescription practice. The objective was to investigate the relationshipbetween maximum dynamic force (MDF of inferior limbs and the static and dynamic balances.Participated in the study 60 individuals, with 18 to 24 years old, strength training apprentices.The MDF was available by mean the One Maximum Repetition (1MR in “leg press” and “kneeextension” and motor testes to available of static and dynamic balances. The correlation testsand multiple linear regression were applied. The force and balance variables showed correlationin females (p=0.038. The corporal mass and static balance showed correlation for the males(p=0.045. The explication capacity at MDF and practices time were small: 13% for staticbalance in males, 18% and 17%, respectively, for static and dynamic balance in females. Inconclusion: the MDF of inferior limbs showed low predictive capacity for performance in staticand dynamic balances, especially for males.

Performance Based Clustering for Benchmarking of Container Ports: an Application of Dea and Cluster Analysis Technique

Directory of Open Access Journals (Sweden)

Jie Wu

2010-12-01

Full Text Available The operational performance of container ports has received more and more attentions in both academic and practitioner circles, the performance evaluation and process improvement of container ports have also been the focus of several studies. In this paper, Data Envelopment Analysis (DEA, an effective tool for relative efficiency assessment, is utilized for measuring the performances and benchmarking of the 77 world container ports in 2007. The used approaches in the current study consider four inputs (Capacity of Cargo Handling Machines, Number of Berths, Terminal Area and Storage Capacity and a single output (Container Throughput. The results for the efficiency scores are analyzed, and a unique ordering of the ports based on average cross efficiency is provided, also cluster analysis technique is used to select the more appropriate targets for poorly performing ports to use as benchmarks.

基于5A景区最大承载量和游客接待量的旅游供需关系模型研究%Study of Mathematical Model Between Tourism Supply and Demand Based on Relationship of the 5A Level Scenic Spots' Maximum Carrying Capacity and the Amount of the Tourists

Institute of Scientific and Technical Information of China (English)

刘静; 刘耀龙; 段锦

2017-01-01

旅游承载量是反映旅游供给能力的重要指标,游客接待量是衡量旅游需求状况的常用指标.在分析我国5A级景区最大承载量空间分异特征的基础上,对2014年各省市5A级景区日最大承载量和年游客接待量进行相关性和回归分析,构建基于景区承载量和游客接待量的旅游供需关系模型.结果表明:(1)5A级景区最大承载量和游客接待量之间存在显著的正相关关系;(2)旅游供需关系模型可由复合函数定量表征;(3)模型能够预测旅游供需变化,对旅游业发展具有一定的指示意义.%Tourism carrying capacity is an important index to reflect the tourism supply capacity, and the amount of the tourists is a common index to measure tourism demand. On the basis of the analysis of the spatial distribution characteristics of 5A level scenic spots' maximum carrying capacity, the paper carries out correlation and regression analysis about the 5A level scenic' maximum carrying capacity and the amount of the tourists. Sample data is calculated or statistical results of 31 provinces in 2014. Tourism supply and demand model is constructed based on the relationship between the 5A level scenic spots' maximum carrying capacity and the amount of the tourists. Results indicate: (1)There is a significant positive correlation between the 5A level scenic spot'maximum carrying capacity and the amount of tourists; (2)The model of tourism supply and demand relations can be quantitatively characterized by complex functions;(3)The model can predict the change of tourism supply and demand, which have referential meaning to the development of tourism.

MORE REMOTE GLOBULAR CLUSTERS IN THE OUTER HALO OF M31

International Nuclear Information System (INIS)

Di Tullio Zinn, Graziella; Zinn, Robert

2013-01-01

We searched the Sloan Digital Sky Survey for outer halo globular clusters (GCs) around M31. Our search of non-stellar objects, within the limits of 0.3 ≤ (g – i) 0 ≤ 1.5 and 14.0 ≤ r 0 ≤ 19.0 concentrated in some remote areas of the extended halo, to a maximum projected distance of 240 kpc, for a total of approximately 200 deg 2 . Another ∼50 deg 2 , ∼5-75 kpc from M31, were surveyed as test areas. In these areas, we identified 39 GCs and 2 GC candidates, 84% of the previously known GCs (93% of the 'classical GCs' and 40% of the 'halo extended clusters', on the cluster classification scheme of Huxor et al.). For the entire survey, we visually inspected 78,516 objects for morphological evidence of cluster status, and we identified 18 new clusters, and 75 candidate clusters. The new clusters include 15 classical globulars and 3 clusters of lower density. Six of the clusters reside in the remote areas of the outer halo, beyond projected distances of 100 kpc. Previously, only MGC1 was found beyond this limit at 117 kpc. The farthest cluster discovered in this survey lies at a projected radius of 158 kpc from M31, assuming that the M31 distance is 780 kpc.

Density functional study of structural and electronic properties of bimetallic silver-gold clusters: Comparison with pure gold and silver clusters

Science.gov (United States)

Bonacic-Koutecky, Vlasta; Burda, Jaroslav; Mitric, Roland; Ge, Maofa; Zampella, Giuseppe; Fantucci, Piercarlo

2002-08-01

Bimetallic silver-gold clusters offer an excellent opportunity to study changes in metallic versus "ionic" properties involving charge transfer as a function of the size and the composition, particularly when compared to pure silver and gold clusters. We have determined structures, ionization potentials, and vertical detachment energies for neutral and charged bimetallic AgmAun 3[less-than-or-equal](m+n)[less-than-or-equal]5 clusters. Calculated VDE values compare well with available experimental data. In the stable structures of these clusters Au atoms assume positions which favor the charge transfer from Ag atoms. Heteronuclear bonding is usually preferred to homonuclear bonding in clusters with equal numbers of hetero atoms. In fact, stable structures of neutral Ag2Au2, Ag3Au3, and Ag4Au4 clusters are characterized by the maximum number of hetero bonds and peripheral positions of Au atoms. Bimetallic tetramer as well as hexamer are planar and have common structural properties with corresponding one-component systems, while Ag4Au4 and Ag8 have 3D forms in contrast to Au8 which assumes planar structure. At the density functional level of theory we have shown that this is due to participation of d electrons in bonding of pure Aun clusters while s electrons dominate bonding in pure Agm as well as in bimetallic clusters. In fact, Aun clusters remain planar for larger sizes than Agm and AgnAun clusters. Segregation between two components in bimetallic systems is not favorable, as shown in the example of Ag5Au5 cluster. We have found that the structures of bimetallic clusters with 20 atoms Ag10Au10 and Ag12Au8 are characterized by negatively charged Au subunits embedded in Ag environment. In the latter case, the shape of Au8 is related to a pentagonal bipyramid capped by one atom and contains three exposed negatively charged Au atoms. They might be suitable for activating reactions relevant to catalysis. According to our findings the charge transfer in bimetallic

A new physical performance classification system for elite handball players: cluster analysis

Science.gov (United States)

Chirosa, Ignacio J.; Robinson, Joseph E.; van der Tillaar, Roland; Chirosa, Luis J.; Martín, Isidoro Martínez

2016-01-01

Abstract The aim of the present study was to identify different cluster groups of handball players according to their physical performance level assessed in a series of physical assessments, which could then be used to design a training program based on individual strengths and weaknesses, and to determine which of these variables best identified elite performance in a group of under-19 [U19] national level handball players. Players of the U19 National Handball team (n=16) performed a set of tests to determine: 10 m (ST10) and 20 m (ST20) sprint time, ball release velocity (BRv), countermovement jump (CMJ) height and squat jump (SJ) height. All players also performed an incremental-load bench press test to determine the 1 repetition maximum (1RMest), the load corresponding to maximum mean power (LoadMP), the mean propulsive phase power at LoadMP (PMPPMP) and the peak power at LoadMP (PPEAKMP). Cluster analyses of the test results generated four groupings of players. The variables best able to discriminate physical performance were BRv, ST20, 1RMest, PPEAKMP and PMPPMP. These variables could help coaches identify talent or monitor the physical performance of athletes in their team. Each cluster of players has a particular weakness related to physical performance and therefore, the cluster results can be applied to a specific training programmed based on individual needs. PMID:28149376

A new physical performance classification system for elite handball players: cluster analysis

Directory of Open Access Journals (Sweden)

Bautista Iker J.

2016-06-01

Full Text Available The aim of the present study was to identify different cluster groups of handball players according to their physical performance level assessed in a series of physical assessments, which could then be used to design a training program based on individual strengths and weaknesses, and to determine which of these variables best identified elite performance in a group of under-19 [U19] national level handball players. Players of the U19 National Handball team (n=16 performed a set of tests to determine: 10 m (ST10 and 20 m (ST20 sprint time, ball release velocity (BRv, countermovement jump (CMJ height and squat jump (SJ height. All players also performed an incremental-load bench press test to determine the 1 repetition maximum (1RMest, the load corresponding to maximum mean power (LoadMP, the mean propulsive phase power at LoadMP (PMPPMP and the peak power at LoadMP (PPEAKMP. Cluster analyses of the test results generated four groupings of players. The variables best able to discriminate physical performance were BRv, ST20, 1RMest, PPEAKMP and PMPPMP. These variables could help coaches identify talent or monitor the physical performance of athletes in their team. Each cluster of players has a particular weakness related to physical performance and therefore, the cluster results can be applied to a specific training programmed based on individual needs.

Thermal-hydraulic experiments with a cluster of 12 roughened rods

International Nuclear Information System (INIS)

Rehme, K.

1981-02-01

Distributions of temperatures and pressures were measured on a cluster of 12 electrically heated tubes. 84 thermocouples were used to measure the temperatures. The heated part of the tubes was artificially roughened by trapezoidal transverse ribs. The experiments with helium and nitrogen as coolants covered a range of Reynolds numbers between 470 and 1.8 x 10 5 . The maximum linear rod power was 45.8 kWm -1 , the maximum measured wall temperature 1062K (789 0 C). The report contains the description of the test section and all tabulated experimental results. (orig.) [de

Latitudinal and seasonal capacity of the surface oceans as a reservoir of polychlorinated biphenyls

International Nuclear Information System (INIS)

Jurado, Elena; Lohmann, Rainer; Meijer, Sandra; Jones, Kevin C.; Dachs, Jordi

2004-01-01

The oceans play an important role as a global reservoir and ultimate sink of persistent organic pollutants (POPs) such as polychlorinated biphenyls congeners (PCBs). However, the physical and biogeochemical variables that affect the oceanic capacity to retain PCBs show an important spatial and temporal variability which have not been studied in detail, so far. The objective of this paper is to assess the seasonal and spatial variability of the ocean's maximum capacity to act as a reservoir of atmospherically transported and deposited PCBs. A level I fugacity model is used which incorporates the environmental variables of temperature, phytoplankton biomass, and mixed layer depth, as determined from remote sensing and from climatological datasets. It is shown that temperature, phytoplankton biomass and mixed layer depth influence the potential PCB reservoir of the oceans, being phytoplankton biomass specially important in the oceanic productive regions. The ocean's maximum capacities to hold PCBs are estimated. They are compared to a budget of PCBs in the surface oceans derived using a level III model that assumes steady state and which incorporates water column settling fluxes as a loss process. Results suggest that settling fluxes will keep the surface oceanic reservoir of PCBs well below its maximum capacity, especially for the more hydrophobic compounds. The strong seasonal and latitudinal variability of the surface ocean's storage capacity needs further research, because it plays an important role in the global biogeochemical cycles controlling the ultimate sink of PCBs. Because this modeling exercise incorporates variations in downward fluxes driven by phytoplankton and the extent of the water column mixing, it predicts more complex latitudinal variations in PCBs concentrations than those previously suggested. - Model calculations estimate the latitudinal and seasonal storage capacity of the surface oceans for PCBs

A measurement of gravitational lensing of the cosmic microwave background by galaxy clusters using data from the south pole telescope

Energy Technology Data Exchange (ETDEWEB)

Baxter, E. J.; Keisler, R.; Dodelson, S.; Aird, K. A.; Allen, S. W.; Ashby, M. L. N.; Bautz, M.; Bayliss, M.; Benson, B. A.; Bleem, L. E.; Bocquet, S.; Brodwin, M.; Carlstrom, J. E.; Chang, C. L.; Chiu, I.; Cho, H-M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; Desai, S.; Dietrich, J. P.; de Haan, T.; Dobbs, M. A.; Foley, R. J.; Forman, W. R.; George, E. M.; Gladders, M. D.; Gonzalez, A. H.; Halverson, N. W.; Harrington, N. L.; Hennig, C.; Hoekstra, H.; Holder, G. P.; Holzapfel, W. L.; Hou, Z.; Hrubes, J. D.; Jones, C.; Knox, L.; Lee, A. T.; Leitch, E. M.; Liu, J.; Lueker, M.; Luong-Van, D.; Mantz, A.; Marrone, D. P.; McDonald, M.; McMahon, J. J.; Meyer, S. S.; Millea, M.; Mocanu, L. M.; Murray, S. S.; Padin, S.; Pryke, C.; Reichardt, C. L.; Rest, A.; Ruhl, J. E.; Saliwanchik, B. R.; Saro, A.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Song, J.; Spieler, H. G.; Stalder, B.; Stanford, S. A.; Staniszewski, Z.; Stark, A. A.; Story, K. T.; van Engelen, A.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zahn, O.; Zenteno, A.

2015-06-20

Clusters of galaxies are expected to gravitationally lens the cosmic microwave background (CMB) and thereby generate a distinct signal in the CMB on arcminute scales. Measurements of this effect can be used to constrain the masses of galaxy clusters with CMB data alone. Here we present a measurement of lensing of the CMB by galaxy clusters using data from the South Pole Telescope (SPT). We develop a maximum likelihood approach to extract the CMB cluster lensing signal and validate the method on mock data. We quantify the effects on our analysis of several potential sources of systematic error and find that they generally act to reduce the best-fit cluster mass. It is estimated that this bias to lower cluster mass is roughly 0.85σ in units of the statistical error bar, although this estimate should be viewed as an upper limit. We apply our maximum likelihood technique to 513 clusters selected via their Sunyaev–Zeldovich (SZ) signatures in SPT data, and rule out the null hypothesis of no lensing at 3.1σ. The lensing-derived mass estimate for the full cluster sample is consistent with that inferred from the SZ flux: ${M}_{200,\\mathrm{lens}}={0.83}_{-0.37}^{+0.38}\\;{M}_{200,\\mathrm{SZ}}$ (68% C.L., statistical error only).

40 CFR Appendix D to Part 72 - Calculation of Potential Electric Output Capacity

Science.gov (United States)

2010-07-01

... efficiency of the boiler. (3) To express this in MWe, the standards conversion of 3413 Btu to 1 kw-hr is used... design heat input from the boiler by the following equation: EC10NO91.003 For example: (1) Assume a boiler with a maximum design heat input capacity of 340 million Btu/hr. (2) One-third of the maximum...

Peak capacity and peak capacity per unit time in capillary and microchip zone electrophoresis.

Science.gov (United States)

Foley, Joe P; Blackney, Donna M; Ennis, Erin J

2017-11-10

The origins of the peak capacity concept are described and the important contributions to the development of that concept in chromatography and electrophoresis are reviewed. Whereas numerous quantitative expressions have been reported for one- and two-dimensional separations, most are focused on chromatographic separations and few, if any, quantitative unbiased expressions have been developed for capillary or microchip zone electrophoresis. Making the common assumption that longitudinal diffusion is the predominant source of zone broadening in capillary electrophoresis, analytical expressions for the peak capacity are derived, first in terms of migration time, diffusion coefficient, migration distance, and desired resolution, and then in terms of the remaining underlying fundamental parameters (electric field, electroosmotic and electrophoretic mobilities) that determine the migration time. The latter expressions clearly illustrate the direct square root dependence of peak capacity on electric field and migration distance and the inverse square root dependence on solute diffusion coefficient. Conditions that result in a high peak capacity will result in a low peak capacity per unit time and vice-versa. For a given symmetrical range of relative electrophoretic mobilities for co- and counter-electroosmotic species (cations and anions), the peak capacity increases with the square root of the electric field even as the temporal window narrows considerably, resulting in a significant reduction in analysis time. Over a broad relative electrophoretic mobility interval [-0.9, 0.9], an approximately two-fold greater amount of peak capacity can be generated for counter-electroosmotic species although it takes about five-fold longer to do so, consistent with the well-known bias in migration time and resolving power for co- and counter-electroosmotic species. The optimum lower bound of the relative electrophoretic mobility interval [μ r,Z , μ r,A ] that provides the maximum

Intermediate Collaborative Adaptive Management Strategies Build Stakeholder Capacity

Directory of Open Access Journals (Sweden)

Martha C. Monroe

2013-06-01

Full Text Available Efforts to implement collaborative adaptive management (CAM often suffer from challenges, such as an unwillingness of managers to share power, unresolved conflicts between stakeholders, and lack of capacity among stakeholders. Some aspects considered essential to CAM, e.g., trust and stakeholder capacity, may be more usefully viewed as goals for intermediate strategies rather than a set of initial conditions. From this perspective, intermediate steps that focus on social learning and building experience could overcome commonly cited barriers to CAM. An exploration of Springs Basin Working Groups, organized around major clusters of freshwater springs in north Florida, provides a case study of how these intermediate steps enable participants to become more reasonable and engaged. This strategy may be easily implemented by agencies beginning a CAM process.

Molecular dynamics simulation of nanoscale surface diffusion of heterogeneous adatoms clusters

International Nuclear Information System (INIS)

Imran, Muhammad; Hussain, Fayyaz; Ullah, Hafeez; Ahmad, Ejaz; Rashid, Muhammad; Ismail, Muhammad; Cai, Yongqing; Javid, M Arshad; Ahmad, S A

2016-01-01

Molecular dynamics simulation employing the embedded atom method potential is utilized to investigate nanoscale surface diffusion mechanisms of binary heterogeneous adatoms clusters at 300 K, 500 K, and 700 K. Surface diffusion of heterogeneous adatoms clusters can be vital for the binary island growth on the surface and can be useful for the formation of alloy-based thin film surface through atomic exchange process. The results of the diffusion process show that at 300 K, the diffusion of small adatoms clusters shows hopping, sliding, and shear motion; whereas for large adatoms clusters (hexamer and above), the diffusion is negligible. At 500 K, small adatoms clusters, i.e., dimer, show almost all possible diffusion mechanisms including the atomic exchange process; however no such exchange is observed for adatoms clusters greater than dimer. At 700 K, the exchange mechanism dominates for all types of clusters, where Zr adatoms show maximum tendency and Ag adatoms show minimum or no tendency toward the exchange process. Separation and recombination of one or more adatoms are also observed at 500 K and 700 K. The Ag adatoms also occupy pop-up positions over the adatoms clusters for short intervals. At 700 K, the vacancies are also generated in the vicinity of the adatoms cluster, vacancy formation, filling, and shifting can be observed from the results. (paper)

Effect of laser spot size on fusion neutron yield in laser–deuterium cluster interactions

International Nuclear Information System (INIS)

Chen Guanglong; Lu Haiyang; Wang Cheng; Liu Jiansheng; Li Ruxin; Ni Guoquan; Xu Zhizhan

2008-01-01

The effect of the laser spot size on the neutron yield of table-top nuclear fusion from explosions of a femtosecond intense laser pulse heated deuterium clusters is investigated by using a simplified model, in which the cluster size distribution and the energy attenuation of the laser as it propagates through the cluster jet are taken into account. It has been found that there exists a proper laser spot size for the maximum fusion neutron yield for a given laser pulse and a specific deuterium gas cluster jet. The proper spot size, which is dependent on the laser parameters and the cluster jet parameters, has been calculated and compared with the available experimental data. A reasonable agreement between the calculated results and the published experimental results is found

Energy Efficient Clustering in Multi-hop Wireless Sensor Networks Using Differential Evolutionary MOPSO

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D. Rajendra Prasad

Full Text Available ABSTRACT The primary challenge in organizing sensor networks is energy efficacy. This requisite for energy efficacy is because sensor nodes capacities are limited and replacing them is not viable. This restriction further decreases network lifetime. Node lifetime varies depending on the requisites expected of its battery. Hence, primary element in constructing sensor networks is resilience to deal with decreasing lifetime of all sensor nodes. Various network infrastructures as well as their routing protocols for reduction of power utilization as well as to prolong network lifetime are studied. After analysis, it is observed that network constructions that depend on clustering are the most effective methods in terms of power utilization. Clustering divides networks into inter-related clusters such that every cluster has several sensor nodes with a Cluster Head (CH at its head. Sensor gathered information is transmitted to data processing centers through CH hierarchy in clustered environments. The current study utilizes Multi-Objective Particle Swarm Optimization (MOPSO-Differential Evolution (DE (MOPSO-DE technique for optimizing clustering.

Anomalous Behavior of Electronic Heat Capacity of Strongly Correlated Iron Monosilicide

Science.gov (United States)

Povzner, A. A.; Volkov, A. G.; Nogovitsyna, T. A.

2018-04-01

The paper deals with the electronic heat capacity of iron monosilicide FeSi subjected to semiconductor-metal thermal transition during which the formation of its spintronic properties is observed. The proposed model which considers pd-hybridization of strongly correlated d-electrons with non-correlated p-electrons, demonstrates a connection of their contribution to heat capacity in the insulator phase with paramagnon effects and fluctuations of occupation numbers for p- and d-states. In a slitless state, the temperature curve of heat capacity is characterized by a maximum appeared due to normalization of the electron density of states using fluctuating exchange fields. At higher temperatures, a linear growth in heat capacity occurs due to paramagnon effects. The correlation between the model parameters and the first-principles calculation provides the electron contribution to heat capacity, which is obtained from the experimental results on phonon heat capacity. Anharmonicity of phonons is connected merely with the thermal expansion of the crystal lattice.

Steam separator uprating by elimination of capacity-limiting mechanisms

International Nuclear Information System (INIS)

Parkinson, J.R.; Pruster, W.P.; Kidwell, J.H.; Schneider, W.G.

1985-01-01

Advanced steam/water separation equipment for nuclear steam generator application is required for new equipment manufacture and also for retrofit. For new equipment applications, the desire for higher capacity is driven by competitiveness which requires maximum throughput in the most compact package. For retrofit applications, which have arisen due to the poor performance of some of the original equipment, the need is for high capacity separators which can fit into the existing pressure vessel envelope and not only correct the performance problem, but also allow for uprated plant output. This paper describes the development of such advanced steam separators

Detecting Gravitational Lensing of the Cosmic Microwave Background by Galaxy Clusters

Energy Technology Data Exchange (ETDEWEB)

Baxter, Eric Jones [Univ. of Chicago, IL (United States)

2014-08-01

Clusters of galaxies gravitationally lens the Cosmic Microwave Background (CMB) leading to a distinct signal in the CMB on arcminute scales. Measurement of the cluster lensing effect offers the exciting possibility of constraining the masses of galaxy clusters using CMB data alone. Improved constraints on cluster masses are in turn essential to the use of clusters as cosmological probes: uncertainties in cluster masses are currently the dominant systematic affecting cluster abundance constraints on cosmology. To date, however, the CMB cluster lensing signal remains undetected because of its small magnitude and angular size. In this thesis, we develop a maximum likelihood approach to extracting the signal from CMB temperature data. We validate the technique by applying it to mock data designed to replicate as closely as possible real data from the South Pole Telescope’s (SPT) Sunyaev-Zel’dovich (SZ) survey: the effects of the SPT beam, transfer function, instrumental noise and cluster selection are incorporated. We consider the effects of foreground emission on the analysis and show that uncertainty in amount of foreground lensing results in a small systematic error on the lensing constraints. Additionally, we show that if unaccounted for, the SZ effect leads to unacceptably large biases on the lensing constraints and develop an approach for removing SZ contamination. The results of the mock analysis presented here suggest that a 4σ first detection of the cluster lensing effect can be achieved with current SPT-SZ data.

High capacity V-based metal hydride electrodes for rechargeable batteries

OpenAIRE

Yang, Heng; Weadock, Nicholas J.; Tan, Hongjin; Fultz, Brent

2017-01-01

We report the successful development of Ti_(29)V_(62−x)Ni_9Cr_x (x = 0, 6, 12) body centered cubic metal hydride (MH) electrodes by addressing vanadium corrosion and dissolution in KOH solutions. By identifying oxygen as the primary source of corrosion and eliminating oxygen with an Ar-purged cell, the Cr-free Ti_(29)V_(62)Ni_9 alloy electrode achieved a maximum capacity of 594 mAh g^(-1), double the capacity of commercial AB_5 MH electrodes. With coin cells designed to minimize oxygen evolut...

One feature of the activated southern Ordos block: the Ziwuling small earthquake cluster

Directory of Open Access Journals (Sweden)

Li Yuhang

2014-08-01

Full Text Available Small earthquakes (Ms > 2.0 have been recorded from 1970 to the present day and reveal a significant difference in seismicity between the stable Ordos block and its active surrounding area. The southern Ordos block is a conspicuous small earthquake belt clustered and isolated along the NNW direction and extends to the inner stable Ordos block; no active fault can match this small earthquake cluster. In this paper, we analyze the dynamic mechanism of this small earthquake cluster based on the GPS velocity field (from 1999 to 2007, which are mainly from Crustal Movement Observation Network of China (CMONOC with respect to the north and south China blocks. The principal direction of strain rate field, the expansion ratefield, the maximum shear strain rate, and the rotation rate were constrained using the GPS velocity field. The results show that the velocity field, which is bounded by the small earthquake cluster from Tongchuan to Weinan, differs from the strain rate field, and the crustal deformation is left-lateral shear. This left-lateral shear belt not only spatially coincides with the Neo-tectonic belt in the Weihe Basin but also with the NNW small earthquake cluster (the Ziwuling small earthquake cluster. Based on these studies, we speculate that the NNW small earthquake cluster is caused by left-lateral shear slip, which is prone to strain accumulation. When the strain releases along the weak zone of structure, small earthquakes diffuse within its upper crust. The maximum principal compression strees direction changed from NE-SW to NEE-SWW, and the former reverse faults in the southwestern margin of the Ordos block became a left-lateral strike slip due to readjustment of the tectonic strees field after the middle Pleistocene. The NNW Neo-tectonic belt in the Weihe Basin, the different movement character of the inner Weihe Basin (which was demonstrated through GPS measurements and the small earthquake cluster belt reflect the activated

Nickel group cluster anion reactions with carbon monoxide: Rate coefficients and chemisorption efficiency

Science.gov (United States)

Hintz, Paul A.; Ervin, Kent M.

1994-04-01

Reactions of Ni-n(n=3-10), Pd-n(n=3-8), and Pt-n(n=3-7) with CO are studied in a flow tube reactor. Bimolecular rate coefficients are measured for the association reaction of CO adsorbing on the cluster surface. The rate coefficients range from about 10% of the collision rate for the trimer anions to near the collision rate for clusters larger than four atoms. The maximum number of CO molecules that bind to each cluster is determined. Whereas the saturation limits for nickel are typical for an 18 electron transition metal, the limits for platinum are lower, reflecting the electron deficient structures observed in condensed phase chemistry. The CO saturated palladium clusters represent the first examples of saturated binary palladium carbonyl compounds. Comparisons are made to similar studies on metal cation and neutral clusters and also to surface scattering studies of nickel group metals.

Capacity Prediction Model Based on Limited Priority Gap-Acceptance Theory at Multilane Roundabouts

Directory of Open Access Journals (Sweden)

Zhaowei Qu

2014-01-01

Full Text Available Capacity is an important design parameter for roundabouts, and it is the premise of computing their delay and queue. Roundabout capacity has been studied for decades, and empirical regression model and gap-acceptance model are the two main methods to predict it. Based on gap-acceptance theory, by considering the effect of limited priority, especially the relationship between limited priority factor and critical gap, a modified model was built to predict the roundabout capacity. We then compare the results between Raff’s method and maximum likelihood estimation (MLE method, and the MLE method was used to predict the critical gaps. Finally, the predicted capacities from different models were compared, with the observed capacity by field surveys, which verifies the performance of the proposed model.

A density functional study of carbon monoxide adsorption on small cationic, neutral, and anionic gold clusters

Science.gov (United States)

Wu, X.; Senapati, L.; Nayak, S. K.; Selloni, A.; Hajaligol, M.

2002-08-01

CO adsorption on small cationic, neutral, and anionic Aun (n=1-6) clusters has been investigated using density functional theory in the generalized gradient approximation. Among various possible CO adsorption sites, the on-top (one-fold coordinated) is found to be the most favorable one, irrespective of the charge state of the cluster. In addition, planar structures are preferred by both the bare and the CO-adsorbed clusters. The adsorption energies of CO on the cationic clusters are generally greater than those on the neutral and anionic complexes, and decrease with size. The adsorption energies on the anions, instead, increase with cluster size and reach a local maximum at Au5CO-, in agreement with recent experiment. The differences in adsorption energies for the different charge states decrease with increasing cluster size.

Dielectric-spectroscopy approach to ferrofluid nanoparticle clustering induced by an external electric field.

Science.gov (United States)

Rajnak, Michal; Kurimsky, Juraj; Dolnik, Bystrik; Kopcansky, Peter; Tomasovicova, Natalia; Taculescu-Moaca, Elena Alina; Timko, Milan

2014-09-01

An experimental study of magnetic colloidal particles cluster formation induced by an external electric field in a ferrofluid based on transformer oil is presented. Using frequency domain isothermal dielectric spectroscopy, we study the influence of a test cell electrode separation distance on a low-frequency relaxation process. We consider the relaxation process to be associated with an electric double layer polarization taking place on the particle surface. It has been found that the relaxation maximum considerably shifts towards lower frequencies when conducting the measurements in the test cells with greater electrode separation distances. As the electric field intensity was always kept at a constant value, we propose that the particle cluster formation induced by the external ac electric field accounts for that phenomenon. The increase in the relaxation time is in accordance with the Schwarz theory of electric double layer polarization. In addition, we analyze the influence of a static electric field generated by dc bias voltage on a similar shift in the relaxation maximum position. The variation of the dc electric field for the hysteresis measurements purpose provides understanding of the development of the particle clusters and their decay. Following our results, we emphasize the utility of dielectric spectroscopy as a simple, complementary method for detection and study of clusters of colloidal particles induced by external electric field.

Effect of a High-intensity Interval Training method on maximum oxygen consumption in Chilean schoolchildren

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Sergio Galdames-Maliqueo

2017-12-01

Full Text Available Introduction: The low levels of maximum oxygen consumption (VO2max evaluated in Chilean schoolchildren suggest the startup of trainings that improve the aerobic capacity. Objective: To analyze the effect of a High-intensity Interval Training method on maximum oxygen consumption in Chilean schoolchildren. Materials and methods: Thirty-two high school students from the eighth grade, who were divided into two groups, were part of the study (experimental group = 16 students and control group = 16 students. The main analyzed variable was the maximum oxygen consumption through the Course Navette Test. A High-intensity Interval training method was applied based on the maximum aerobic speed obtained through the Test. A mixed ANOVA was used for statistical analysis. Results: The experimental group showed a significant increase in the Maximum Oxygen Consumption between the pretest and posttest when compared with the control group (p < 0.0001. Conclusion: The results of the study showed a positive effect of the High-intensity Interval Training on the maximum consumption of oxygen. At the end of the study, it is concluded that High-intensity Interval Training is a good stimulation methodology for Chilean schoolchildren.

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.

Approximate maximum parsimony and ancestral maximum likelihood.

Science.gov (United States)

Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

2010-01-01

We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

Flower-like SnO2/graphene composite for high-capacity lithium storage

International Nuclear Information System (INIS)

Liu Hongdong; Huang Jiamu; Li Xinlu; Liu Jia; Zhang Yuxin; Du Kun

2012-01-01

Flower-like SnO 2 /graphene composite is synthesized by a simple hydrothermal method for high-capacity lithium storage. The as-prepared products are characterized by XRD, FTIR, FESEM, TGA and Nitrogen adsorption/desorption. The electrochemical performance of the flower-like SnO 2 /graphene composite is measured by cyclic voltammetry and galvanostatic charge/discharge cycling. The results show that the flower-like SnO 2 nanorod clusters are 800 nm in size and homogeneously adhere on graphene sheets. The flower-like SnO 2 /graphene composite displays superior Li-battery performance with large reversible capacity, excellent cyclic performance and good rate capability.

ON THE MAXIMUM MASS OF STELLAR BLACK HOLES

International Nuclear Information System (INIS)

Belczynski, Krzysztof; Fryer, Chris L.; Bulik, Tomasz; Ruiter, Ashley; Valsecchi, Francesca; Vink, Jorick S.; Hurley, Jarrod R.

2010-01-01

We present the spectrum of compact object masses: neutron stars and black holes (BHs) that originate from single stars in different environments. In particular, we calculate the dependence of maximum BH mass on metallicity and on some specific wind mass loss rates (e.g., Hurley et al. and Vink et al.). Our calculations show that the highest mass BHs observed in the Galaxy M bh ∼ 15 M sun in the high metallicity environment (Z = Z sun = 0.02) can be explained with stellar models and the wind mass loss rates adopted here. To reach this result we had to set luminous blue variable mass loss rates at the level of ∼10 -4 M sun yr -1 and to employ metallicity-dependent Wolf-Rayet winds. With such winds, calibrated on Galactic BH mass measurements, the maximum BH mass obtained for moderate metallicity (Z = 0.3 Z sun = 0.006) is M bh,max = 30 M sun . This is a rather striking finding as the mass of the most massive known stellar BH is M bh = 23-34 M sun and, in fact, it is located in a small star-forming galaxy with moderate metallicity. We find that in the very low (globular cluster-like) metallicity environment the maximum BH mass can be as high as M bh,max = 80 M sun (Z = 0.01 Z sun = 0.0002). It is interesting to note that X-ray luminosity from Eddington-limited accretion onto an 80 M sun BH is of the order of ∼10 40 erg s -1 and is comparable to luminosities of some known ultra-luminous X-ray sources. We emphasize that our results were obtained for single stars only and that binary interactions may alter these maximum BH masses (e.g., accretion from a close companion). This is strictly a proof-of-principle study which demonstrates that stellar models can naturally explain even the most massive known stellar BHs.

Research on Energy-Saving Production Scheduling Based on a Clustering Algorithm for a Forging Enterprise

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Yifei Tong

2016-02-01

Full Text Available Energy efficiency is a buzzword of the 21st century. With the ever growing need for energy efficient and low-carbon production, it is a big challenge for high energy-consumption enterprises to reduce their energy consumption. To this aim, a forging enterprise, DVR (the abbreviation of a forging enterprise, is researched. Firstly, an investigation into the production processes of DVR is given as well as an analysis of forging production. Then, the energy-saving forging scheduling is decomposed into two sub-problems. One is for cutting and machining scheduling, which is similar to traditional machining scheduling. The other one is for forging and heat treatment scheduling. Thirdly, former forging production scheduling is presented and solved based on an improved genetic algorithm. Fourthly, the latter is discussed in detail, followed by proposed dynamic clustering and stacking combination optimization. The proposed stacking optimization requires making the gross weight of forgings as close to the maximum batch capacity as possible. The above research can help reduce the heating times, and increase furnace utilization with high energy efficiency and low carbon emissions.

A Data-Driven Bidding Model for a Cluster of Price-Responsive Consumers of Electricity

DEFF Research Database (Denmark)

Saez Gallego, Javier; Morales González, Juan Miguel; Zugno, Marco

2016-01-01

This paper deals with the market-bidding problem of a cluster of price-responsive consumers of electricity. We develop an inverse optimization scheme that, recast as a bilevel programming problem, uses price-consumption data to estimate the complex market bid that best captures the price......-response of the cluster. The complex market bid is defined as a series of marginal utility functions plus some constraints on demand, such as maximum pick-up and drop-off rates. The proposed modeling approach also leverages information on exogenous factors that may influence the consumption behavior of the cluster, e...... can be largely captured in the form of a complex market bid, so that this could be ultimately used for the cluster to participate in the wholesale electricity market....

Cluster Head Selection in a Homogeneous Wireless Sensor Network Ensuring Full Connectivity with Minimum Isolated Nodes

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Tapan Kumar Jain

2014-01-01

Full Text Available The research work proposes a cluster head selection algorithm for a wireless sensor network. A node can be a cluster head if it is connected to at least one unique neighbor node where the unique neighbor is the one that is not connected to any other node. If there is no connected unique node then the CH is selected on the basis of residual energy and the number of neighbor nodes. With the increase in number of clusters, the processing energy of the network increases; hence, this algorithm proposes minimum number of clusters which further leads to increased network lifetime. The major novel contribution of the proposed work is an algorithm that ensures a completely connected network with minimum number of isolated nodes. An isolated node will remain only if it is not within the transmission range of any other node. With the maximum connectivity, the coverage of the network is automatically maximized. The superiority of the proposed design is verified by simulation results done in MATLAB, where it clearly depicts that the total numbers of rounds before the network dies out are maximum compared to other existing protocols.

Methodology for Clustering High-Resolution Spatiotemporal Solar Resource Data

Energy Technology Data Exchange (ETDEWEB)

Getman, Dan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lopez, Anthony [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mai, Trieu [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dyson, Mark [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-09-01

In this report, we introduce a methodology to achieve multiple levels of spatial resolution reduction of solar resource data, with minimal impact on data variability, for use in energy systems modeling. The selection of an appropriate clustering algorithm, parameter selection including cluster size, methods of temporal data segmentation, and methods of cluster evaluation are explored in the context of a repeatable process. In describing this process, we illustrate the steps in creating a reduced resolution, but still viable, dataset to support energy systems modeling, e.g. capacity expansion or production cost modeling. This process is demonstrated through the use of a solar resource dataset; however, the methods are applicable to other resource data represented through spatiotemporal grids, including wind data. In addition to energy modeling, the techniques demonstrated in this paper can be used in a novel top-down approach to assess renewable resources within many other contexts that leverage variability in resource data but require reduction in spatial resolution to accommodate modeling or computing constraints.

Cluster protocols in Underwater Sensor Networks: a Research Review

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K. Ovaliadis

2014-07-01

Full Text Available Underwater Wireless Sensor Networks (UWSN have different characteristics in relation to terrestrial wireless sensor networks; such as limited bandwidth capacity, high propagation delays and limited battery power. Although there has been much work completed in developing protocols and models for terrestrial networks, these are rarely applicable for underwater sensor networks. Up to today major efforts have been made for designing efficient protocols while considering the underwater communication characteristics. An important issue on this research area is the construction of an efficient clustering algorithm. Clustering in the context of UWSN is important as it contributes a great deal towards the efficient use of energy resources. This paper reviews the most significant cluster based protocols proposed for UWSN. Major performance issues of these protocols with respect to the network conditions such as packet delivery ratio, average packet delay, node mobility effect and energy consumption are examined. The advantages and disadvantages of each protocol are also pointed out.

Interaction of hydrogen with palladium clusters deposited on graphene

Energy Technology Data Exchange (ETDEWEB)

Alonso, Julio A.; Granja, Alejandra; Cabria, Iván; López, María J. [Departamento de Física Teórica, Atómica y Optica, Universidad de Valladolid, 47011 Valladolid (Spain)

2015-12-31

Hydrogen adsorption on nanoporous carbon materials is a promising technology for hydrogen storage. However, pure carbon materials do not meet the technological requirements due to the week binding of hydrogen to the pore walls. Experimental work has shown that doping with Pd atoms and clusters enhances the storage capacity of porous carbons. Therefore, we have investigated the role played by the Pd dopant on the enhancement mechanisms. By performing density functional calculations, we have found that hydrogen adsorbs on Pd clusters deposited on graphene following two channels, molecular adsorption and dissociative chemisorption. However, desorption of Pd-H complexes competes with desorption of hydrogen, and consequently desorption of Pd-H complexes would spoil the beneficial effect of the dopant. As a way to overcome this difficulty, Pd atoms and clusters can be anchored to defects of the graphene layer, like graphene vacancies. The competition between molecular adsorption and dissociative chemisorption of H{sub 2} on Pd{sub 6} anchored on a graphene vacancy has been studied in detail.

Interaction of hydrogen with palladium clusters deposited on graphene

Science.gov (United States)

Alonso, Julio A.; Granja, Alejandra; Cabria, Iván; López, María J.

2015-12-01

Hydrogen adsorption on nanoporous carbon materials is a promising technology for hydrogen storage. However, pure carbon materials do not meet the technological requirements due to the week binding of hydrogen to the pore walls. Experimental work has shown that doping with Pd atoms and clusters enhances the storage capacity of porous carbons. Therefore, we have investigated the role played by the Pd dopant on the enhancement mechanisms. By performing density functional calculations, we have found that hydrogen adsorbs on Pd clusters deposited on graphene following two channels, molecular adsorption and dissociative chemisorption. However, desorption of Pd-H complexes competes with desorption of hydrogen, and consequently desorption of Pd-H complexes would spoil the beneficial effect of the dopant. As a way to overcome this difficulty, Pd atoms and clusters can be anchored to defects of the graphene layer, like graphene vacancies. The competition between molecular adsorption and dissociative chemisorption of H2 on Pd6 anchored on a graphene vacancy has been studied in detail.

A New Cluster Analysis-Marker-Controlled Watershed Method for Separating Particles of Granular Soils.

Science.gov (United States)

Alam, Md Ferdous; Haque, Asadul

2017-10-18

An accurate determination of particle-level fabric of granular soils from tomography data requires a maximum correct separation of particles. The popular marker-controlled watershed separation method is widely used to separate particles. However, the watershed method alone is not capable of producing the maximum separation of particles when subjected to boundary stresses leading to crushing of particles. In this paper, a new separation method, named as Monash Particle Separation Method (MPSM), has been introduced. The new method automatically determines the optimal contrast coefficient based on cluster evaluation framework to produce the maximum accurate separation outcomes. Finally, the particles which could not be separated by the optimal contrast coefficient were separated by integrating cuboid markers generated from the clustering by Gaussian mixture models into the routine watershed method. The MPSM was validated on a uniformly graded sand volume subjected to one-dimensional compression loading up to 32 MPa. It was demonstrated that the MPSM is capable of producing the best possible separation of particles required for the fabric analysis.

Heavy hitters via cluster-preserving clustering

DEFF Research Database (Denmark)

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

2016-01-01

In the turnstile lp heavy hitters problem with parameter ε, one must maintain a high-dimensional vector xεRn subject to updates of the form update (i,Δ) causing the change xi≤ ← xi + Δ, where iε[n], ΔεR. Upon receiving a query, the goal is to report every "heavy hitter" iε[n] with |xi| ≥ε......|x|p as part of a list L⊆[n] of size O(1/εp), i.e. proportional to the maximum possible number of heavy hitters. For any pε(0,2] the COUNTSKETCH of [CCFC04] solves lp heavy hitters using O(ε-plog n) words of space with O(log n) update time, O(nlog n) query time to output L, and whose output after any query......, 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...

Metal cluster compounds - chemistry and importance; clusters containing isolated main group element atoms, large metal cluster compounds, cluster fluxionality

International Nuclear Information System (INIS)

Walther, B.

1988-01-01

This part of the review on metal cluster compounds deals with clusters containing isolated main group element atoms, with high nuclearity clusters and metal cluster fluxionality. It will be obvious that main group element atoms strongly influence the geometry, stability and reactivity of the clusters. High nuclearity clusters are of interest in there own due to the diversity of the structures adopted, but their intermediate position between molecules and the metallic state makes them a fascinating research object too. These both sites of the metal cluster chemistry as well as the frequently observed ligand and core fluxionality are related to the cluster metal and surface analogy. (author)

A perturbative clustering hyper-heuristic framework for the Danish railway system

DEFF Research Database (Denmark)

M. Pour, Shahrzad; Rasmussen, Kourosh Marjani; Burke, Edmund K.

, we propose a perturbative clustering hyper-heuristic framework. The framework improves an initial solution by reassigning outliers (those tasks that are far away) to a better cluster choice at each iteration while taking balanced crews workloads into account. The framework introduces five lowlevel...... heuristics and employs an adaptive choice function as a robust learning mechanism. The results of adaptive clustering hyper-heuristic are compared with two exact and heuristic assignment algorithms from the literature and with the random hyper-heuristic framework on 12 datasets. In comparison with the exact...... formulation, the proposed framework could obtain promising results and solved the data instances up to 5000 number of tasks. In comparison with heuristic assignment and the random hyper-heuristic, the framework yielded approximately 11%, 27% and 10%,13% mprovement on total distance and the maximum distance...

Estimation of rank correlation for clustered data.

Science.gov (United States)

Rosner, Bernard; Glynn, Robert J

2017-06-30

It is well known that the sample correlation coefficient (R xy ) is the maximum likelihood estimator of the Pearson correlation (ρ xy ) for independent and identically distributed (i.i.d.) bivariate normal data. However, this is not true for ophthalmologic data where X (e.g., visual acuity) and Y (e.g., visual field) are available for each eye and there is positive intraclass correlation for both X and Y in fellow eyes. In this paper, we provide a regression-based approach for obtaining the maximum likelihood estimator of ρ xy for clustered data, which can be implemented using standard mixed effects model software. This method is also extended to allow for estimation of partial correlation by controlling both X and Y for a vector U_ of other covariates. In addition, these methods can be extended to allow for estimation of rank correlation for clustered data by (i) converting ranks of both X and Y to the probit scale, (ii) estimating the Pearson correlation between probit scores for X and Y, and (iii) using the relationship between Pearson and rank correlation for bivariate normally distributed data. The validity of the methods in finite-sized samples is supported by simulation studies. Finally, two examples from ophthalmology and analgesic abuse are used to illustrate the methods. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Assessment of genetic divergence in tomato through agglomerative hierarchical clustering and principal component analysis

International Nuclear Information System (INIS)

Iqbal, Q.; Saleem, M.Y.; Hameed, A.; Asghar, M.

2014-01-01

For the improvement of qualitative and quantitative traits, existence of variability has prime importance in plant breeding. Data on different morphological and reproductive traits of 47 tomato genotypes were analyzed for correlation,agglomerative hierarchical clustering and principal component analysis (PCA) to select genotypes and traits for future breeding program. Correlation analysis revealed significant positive association between yield and yield components like fruit diameter, single fruit weight and number of fruits plant-1. Principal component (PC) analysis depicted first three PCs with Eigen-value higher than 1 contributing 81.72% of total variability for different traits. The PC-I showed positive factor loadings for all the traits except number of fruits plant-1. The contribution of single fruit weight and fruit diameter was highest in PC-1. Cluster analysis grouped all genotypes into five divergent clusters. The genotypes in cluster-II and cluster-V exhibited uniform maturity and higher yield. The D2 statistics confirmed highest distance between cluster- III and cluster-V while maximum similarity was observed in cluster-II and cluster-III. It is therefore suggested that crosses between genotypes of cluster-II and cluster-V with those of cluster-I and cluster-III may exhibit heterosis in F1 for hybrid breeding and for selection of superior genotypes in succeeding generations for cross breeding programme. (author)

Russian Pharmaceutical Companies Export Potential in Emerging Regional Clusters

Directory of Open Access Journals (Sweden)

Elena Vladimirovna Sapir

2016-12-01

Full Text Available This article analyzes a diverse range of the enterprise’s export potential growth factors in emerging pharmaceutical clusters of Central European Russia. Classification and comparative analysis were used to identify export potential attributes (production, finance, labor and marketing, which have allowed to reveal the strong connection of cluster and regional factor groups with the results of export performance. The purpose of the study is to provide exports-seeking pharmaceutical companies with a set of tools to enhance their export potential. The hypothesis that the cumulative impact of the specified attributes leads to the strengthening of pharmaceutical cluster export potential and promotes an effective integration of the region in the world economic space, is developed and tested. The methodology combines the geo-economy-based theory with the theory of clusters competitive advantages. The impacts of export potential growth factors are estimated by using an econometric model based on math statistics. Thus, five Russian regional pharmaceutical clusters (Belgorod, Kaluga, Moscow, Oryol, Yaroslavl are shown. Findings identify an objective causal link between enterprise export potential growth and competitiveness factors of cluster origin (network business chains, production functions interconnectedness and flexibility, production localization. An action plan for the purpose of the maximum use of competitive advantages of the cluster organization for export activities of the entities of the pharmaceutical industry is developed. Conclusions and recommendations of the study are intended to enterprises in pharmaceutical industry and regions’ public authorities, implementing cluster development strategies. It is thus essential to improve marketing and organizational innovations, reduction of commercial expenses under the cluster environment, development of drugs production and delivery chains from R&D to end-users in order to enjoy greater

PREFACE: Nuclear Cluster Conference; Cluster'07

Science.gov (United States)

Freer, Martin

2008-05-01

The Cluster Conference is a long-running conference series dating back to the 1960's, the first being initiated by Wildermuth in Bochum, Germany, in 1969. The most recent meeting was held in Nara, Japan, in 2003, and in 2007 the 9th Cluster Conference was held in Stratford-upon-Avon, UK. As the name suggests the town of Stratford lies upon the River Avon, and shortly before the conference, due to unprecedented rainfall in the area (approximately 10 cm within half a day), lay in the River Avon! Stratford is the birthplace of the `Bard of Avon' William Shakespeare, and this formed an intriguing conference backdrop. The meeting was attended by some 90 delegates and the programme contained 65 70 oral presentations, and was opened by a historical perspective presented by Professor Brink (Oxford) and closed by Professor Horiuchi (RCNP) with an overview of the conference and future perspectives. In between, the conference covered aspects of clustering in exotic nuclei (both neutron and proton-rich), molecular structures in which valence neutrons are exchanged between cluster cores, condensates in nuclei, neutron-clusters, superheavy nuclei, clusters in nuclear astrophysical processes and exotic cluster decays such as 2p and ternary cluster decay. The field of nuclear clustering has become strongly influenced by the physics of radioactive beam facilities (reflected in the programme), and by the excitement that clustering may have an important impact on the structure of nuclei at the neutron drip-line. It was clear that since Nara the field had progressed substantially and that new themes had emerged and others had crystallized. Two particular topics resonated strongly condensates and nuclear molecules. These topics are thus likely to be central in the next cluster conference which will be held in 2011 in the Hungarian city of Debrechen. Martin Freer Participants and Cluster'07

An Enhanced PSO-Based Clustering Energy Optimization Algorithm for Wireless Sensor Network.

Science.gov (United States)

Vimalarani, C; Subramanian, R; Sivanandam, S N

2016-01-01

Wireless Sensor Network (WSN) is a network which formed with a maximum number of sensor nodes which are positioned in an application environment to monitor the physical entities in a target area, for example, temperature monitoring environment, water level, monitoring pressure, and health care, and various military applications. Mostly sensor nodes are equipped with self-supported battery power through which they can perform adequate operations and communication among neighboring nodes. Maximizing the lifetime of the Wireless Sensor networks, energy conservation measures are essential for improving the performance of WSNs. This paper proposes an Enhanced PSO-Based Clustering Energy Optimization (EPSO-CEO) algorithm for Wireless Sensor Network in which clustering and clustering head selection are done by using Particle Swarm Optimization (PSO) algorithm with respect to minimizing the power consumption in WSN. The performance metrics are evaluated and results are compared with competitive clustering algorithm to validate the reduction in energy consumption.

Self-Assembled Gold Nano-Ripple Formation by Gas Cluster Ion Beam Bombardment.

Science.gov (United States)

Tilakaratne, Buddhi P; Chen, Quark Y; Chu, Wei-Kan

2017-09-08

In this study, we used a 30 keV argon cluster ion beam bombardment to investigate the dynamic processes during nano-ripple formation on gold surfaces. Atomic force microscope analysis shows that the gold surface has maximum roughness at an incident angle of 60° from the surface normal; moreover, at this angle, and for an applied fluence of 3 × 10 16 clusters/cm², the aspect ratio of the nano-ripple pattern is in the range of ~50%. Rutherford backscattering spectrometry analysis reveals a formation of a surface gradient due to prolonged gas cluster ion bombardment, although the surface roughness remains consistent throughout the bombarded surface area. As a result, significant mass redistribution is triggered by gas cluster ion beam bombardment at room temperature. Where mass redistribution is responsible for nano-ripple formation, the surface erosion process refines the formed nano-ripple structures.

The role of working memory capacity in autobiographical retrieval: individual differences in strategic search.

Science.gov (United States)

Unsworth, Nash; Spillers, Gregory J; Brewer, Gene A

2012-01-01

Remembering previous experiences from one's personal past is a principal component of psychological well-being, personality, sense of self, decision making, and planning for the future. In the current study the ability to search for autobiographical information in memory was examined by having college students recall their Facebook friends. Individual differences in working memory capacity manifested itself in the search of autobiographical memory by way of the total number of friends remembered, the number of clusters of friends, size of clusters, and the speed with which participants could output their friends' names. Although working memory capacity was related to the ability to search autobiographical memory, participants did not differ in the manner in which they approached the search and used contextual cues to help query their memories. These results corroborate recent theorising, which suggests that working memory is a necessary component of self-generating contextual cues to strategically search memory for autobiographical information.

An imbalance in cluster sizes does not lead to notable loss of power in cross-sectional, stepped-wedge cluster randomised trials with a continuous outcome.

Science.gov (United States)

Kristunas, Caroline A; Smith, Karen L; Gray, Laura J

2017-03-07

The current methodology for sample size calculations for stepped-wedge cluster randomised trials (SW-CRTs) is based on the assumption of equal cluster sizes. However, as is often the case in cluster randomised trials (CRTs), the clusters in SW-CRTs are likely to vary in size, which in other designs of CRT leads to a reduction in power. The effect of an imbalance in cluster size on the power of SW-CRTs has not previously been reported, nor what an appropriate adjustment to the sample size calculation should be to allow for any imbalance. We aimed to assess the impact of an imbalance in cluster size on the power of a cross-sectional SW-CRT and recommend a method for calculating the sample size of a SW-CRT when there is an imbalance in cluster size. The effect of varying degrees of imbalance in cluster size on the power of SW-CRTs was investigated using simulations. The sample size was calculated using both the standard method and two proposed adjusted design effects (DEs), based on those suggested for CRTs with unequal cluster sizes. The data were analysed using generalised estimating equations with an exchangeable correlation matrix and robust standard errors. An imbalance in cluster size was not found to have a notable effect on the power of SW-CRTs. The two proposed adjusted DEs resulted in trials that were generally considerably over-powered. We recommend that the standard method of sample size calculation for SW-CRTs be used, provided that the assumptions of the method hold. However, it would be beneficial to investigate, through simulation, what effect the maximum likely amount of inequality in cluster sizes would be on the power of the trial and whether any inflation of the sample size would be required.

On capacity tradeoffs in secure DS-CDMA packet communications with QOS constraints

International Nuclear Information System (INIS)

Sattar, F.; Mufti, M.

2012-01-01

This paper presents a mathematical framework for analysis of effect of counter mode (CTR) encryption on the traffic capacity of packet communication systems based on direct-sequence, code-division, multiple-access (DS-CDMA). We specify QoS constraints in terms of minimum acceptable mean opinion score (MOS) of voice payload, maximum permissible resource utilization for CTR-mode re-keying and DS-CDMA processing gain. We quantify the trade-offs in system capacity as a function of these constraints. Results show that application of CTR encryption causes error expansion and respecting the QoS constraints while satisfying the desired encryption parameters results in reduction of traffic capacity. (author)

Peak capacity, peak-capacity production rate, and boiling point resolution for temperature-programmed GC with very high programming rates

Science.gov (United States)

Grall; Leonard; Sacks

2000-02-01

Recent advances in column heating technology have made possible very fast linear temperature programming for high-speed gas chromatography. A fused-silica capillary column is contained in a tubular metal jacket, which is resistively heated by a precision power supply. With very rapid column heating, the rate of peak-capacity production is significantly enhanced, but the total peak capacity and the boiling-point resolution (minimum boiling-point difference required for the separation of two nonpolar compounds on a nonpolar column) are reduced relative to more conventional heating rates used with convection-oven instruments. As temperature-programming rates increase, elution temperatures also increase with the result that retention may become insignificant prior to elution. This results in inefficient utilization of the down-stream end of the column and causes a loss in the rate of peak-capacity production. The rate of peak-capacity production is increased by the use of shorter columns and higher carrier gas velocities. With high programming rates (100-600 degrees C/min), column lengths of 6-12 m and average linear carrier gas velocities in the 100-150 cm/s range are satisfactory. In this study, the rate of peak-capacity production, the total peak capacity, and the boiling point resolution are determined for C10-C28 n-alkanes using 6-18 m long columns, 50-200 cm/s average carrier gas velocities, and 60-600 degrees C/min programming rates. It was found that with a 6-meter-long, 0.25-mm i.d. column programmed at a rate of 600 degrees C/min, a maximum peak-capacity production rate of 6.1 peaks/s was obtained. A total peak capacity of about 75 peaks was produced in a 37-s long separation spanning a boiling-point range from n-C10 (174 degrees C) to n-C28 (432 degrees C).

Relating saturation capacity to charge density in strong cation exchangers.

Science.gov (United States)

Steinebach, Fabian; Coquebert de Neuville, Bertrand; Morbidelli, Massimo

2017-07-21

In this work the relation between physical and chemical resin characteristics and the total amount of adsorbed protein (saturation capacity) for ion-exchange resins is discussed. Eleven different packing materials with a sulfo-functionalization and one multimodal resin were analyzed in terms of their porosity, pore size distribution, ligand density and binding capacity. By specifying the ligand density and binding capacity by the total and accessible surface area, two different groups of resins were identified: Below a ligand density of approx. 2.5μmol/m 2 area the ligand density controls the saturation capacity, while above this limit the accessible surface area becomes the limiting factor. This results in a maximum protein uptake of around 2.5mg/m 2 of accessible surface area. The obtained results allow estimating the saturation capacity from independent resin characteristics like the saturation capacity mainly depends on "library data" such as the accessible and total surface area and the charge density. Hence these results give an insight into the fundamentals of protein adsorption and help to find suitable resins, thus limiting the experimental effort in early process development stages. Copyright © 2017 Elsevier B.V. All rights reserved.

Mainshock-Aftershocks Clustering Detection in Volcanic Regions

Science.gov (United States)

Garza Giron, R.; Brodsky, E. E.; Prejean, S. G.

2017-12-01

Crustal earthquakes tend to break their general Poissonean process behavior by gathering into two main kinds of seismic bursts: swarms and mainshock-aftershocks sequences. The former is commonly related to volcanic or geothermal processes whereas the latter is a characteristic feature of tectonically driven seismicity. We explore the mainshock-aftershock clustering behavior of different active volcanic regions in Japan and its comparison to non-volcanic regions. We find that aftershock production in volcanoes shows mainshock-aftershocks clustering similar to what is observed in non-volcanic areas. The ratio of volanic areas that cluster in mainshock-aftershocks sequences vs the areas that do not is comparable to the ratio of non-volcanic regions that show clustering vs the ones that do not. Furthermore, the level of production of aftershocks for most volcanic areas where clustering is present seems to be of the same order of magnitude, or slightly higher, as the median of the non-volcanic regions. An interesting example of highly aftershock-productive volcanoes emerges from the 2000 Miyakejima dike intrusion. A big seismic cluster started to build up rapidly in the south-west flank of Miyakejima to later propagate to the north-west towards the Kozushima and Niijima volcanoes. In Miyakejima the seismicity showed a swarm-like signature with a constant earthquake rate, whereas Kozushima and Niijima both had expressions of highly productive mainshock-aftershocks sequences. These findings are surprising given the alternative mechanisms available in volcanic systems for releasing deviatoric strain. We speculate that aftershock behavior might hold a relationship with the rheological properties of the rocks of each system and with the capacity of a system to accumulate or release the internal pressures caused by magmatic or hydrothermal systems.

Formation of stable products from cluster-cluster collisions

International Nuclear Information System (INIS)

Alamanova, Denitsa; Grigoryan, Valeri G; Springborg, Michael

2007-01-01

The formation of stable products from copper cluster-cluster collisions is investigated by using classical molecular-dynamics simulations in combination with an embedded-atom potential. The dependence of the product clusters on impact energy, relative orientation of the clusters, and size of the clusters is studied. The structures and total energies of the product clusters are analysed and compared with those of the colliding clusters before impact. These results, together with the internal temperature, are used in obtaining an increased understanding of cluster fusion processes

Effect of water cooking on antioxidant capacity of carotenoid-rich vegetables in Taiwan

OpenAIRE

Fuh-Juin Kao; Yu-Shan Chiu; Wen-Dee Chiang

2014-01-01

Carotenoid-rich green leafy vegetables including cilantro, Thai basil leaves, sweet potato leaves, and choy sum were selected to evaluate the effects of water cooking or boiling on their total carotenoid content (TCC), total phenolic content (TPC), and total antioxidant capacity (TAC). The percentage inhibition of peroxidation (%IP), Trolox equivalent antioxidant capacity (TEAC), and metal-chelating effect were used to evaluate TAC. The results indicated that TCC reached the maximum after boi...

A Self-Adaptive Fuzzy c-Means Algorithm for Determining the Optimal Number of Clusters

Science.gov (United States)

Wang, Zhihao; Yi, Jing

2016-01-01

For the shortcoming of fuzzy c-means algorithm (FCM) needing to know the number of clusters in advance, this paper proposed a new self-adaptive method to determine the optimal number of clusters. Firstly, a density-based algorithm was put forward. The algorithm, according to the characteristics of the dataset, automatically determined the possible maximum number of clusters instead of using the empirical rule n and obtained the optimal initial cluster centroids, improving the limitation of FCM that randomly selected cluster centroids lead the convergence result to the local minimum. Secondly, this paper, by introducing a penalty function, proposed a new fuzzy clustering validity index based on fuzzy compactness and separation, which ensured that when the number of clusters verged on that of objects in the dataset, the value of clustering validity index did not monotonically decrease and was close to zero, so that the optimal number of clusters lost robustness and decision function. Then, based on these studies, a self-adaptive FCM algorithm was put forward to estimate the optimal number of clusters by the iterative trial-and-error process. At last, experiments were done on the UCI, KDD Cup 1999, and synthetic datasets, which showed that the method not only effectively determined the optimal number of clusters, but also reduced the iteration of FCM with the stable clustering result. PMID:28042291

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

COMPARISON OF NORMALIZED MAXIMUM AEROBIC CAPACITY AND BODY COMPOSITION OF SUMO WRESTLERS TO ATHLETES IN COMBAT AND OTHER SPORTS

Directory of Open Access Journals (Sweden)

Matthew D. Beekley

2006-07-01

Full Text Available Sumo wrestling is unique in combat sport, and in all of sport. We examined the maximum aerobic capacity and body composition of sumo wrestlers and compared them to untrained controls. We also compared "aerobic muscle quality", meaning VO2max normalized to predicted skeletal muscle mass (SMM (VO2max /SMM, between sumo wrestlers and controls and among previously published data for male athletes from combat, aerobic, and power sports. Sumo wrestlers, compared to untrained controls, had greater (p < 0.05 body mass (mean ± SD; 117.0 ± 4.9 vs. 56.1 ± 9.8 kg, percent fat (24.0 ± 1.4 vs. 13.3 ± 4.5, fat-free mass (88.9 ± 4.2 vs. 48.4 �� 6.8 kg, predicted SMM (48.2 ± 2.9 vs. 20.6 ± 4.7 kg and absolute VO2max (3.6 ± 1.3 vs. 2.5 ± 0.7 L·min-1. Mean VO2max /SMM (ml·kg SMM-1·min-1 was significantly different (p < 0.05 among aerobic athletes (164.8 ± 18.3, combat athletes (which was not different from untrained controls; 131.4 ± 9.3 and 128.6 ± 13.6, respectively, power athletes (96.5 ± 5.3, and sumo wrestlers (71.4 ± 5.3. There was a strong negative correlation (r = - 0.75 between percent body fat and VO2max /SMM (p < 0.05. We conclude that sumo wrestlers have some of the largest percent body fat and fat-free mass and the lowest "aerobic muscle quality" (VO2max /SMM, both in combat sport and compared to aerobic and power sport athletes. Additionally, it appears from analysis of the relationship between SMM and absolute VO2max for all sports that there is a "ceiling" at which increases in SMM do not result in additional increases in absolute VO2max

Unsupervised color image segmentation using a lattice algebra clustering technique

Science.gov (United States)

Urcid, Gonzalo; Ritter, Gerhard X.

2011-08-01

In this paper we introduce a lattice algebra clustering technique for segmenting digital images in the Red-Green- Blue (RGB) color space. The proposed technique is a two step procedure. Given an input color image, the first step determines the finite set of its extreme pixel vectors within the color cube by means of the scaled min-W and max-M lattice auto-associative memory matrices, including the minimum and maximum vector bounds. In the second step, maximal rectangular boxes enclosing each extreme color pixel are found using the Chebychev distance between color pixels; afterwards, clustering is performed by assigning each image pixel to its corresponding maximal box. The two steps in our proposed method are completely unsupervised or autonomous. Illustrative examples are provided to demonstrate the color segmentation results including a brief numerical comparison with two other non-maximal variations of the same clustering technique.

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.

The Behavior of Micro Bubbles and Bubble Cluster in Ultrasound Field

Science.gov (United States)

Yoshizawa, Shin; Matsumoto, Yoichiro

2001-11-01

Ultrasound is widely applied in the clinical field today, such as ultrasound imaging, Extracorporeal Shock Wave Lithotripsy (ESWL) and so on. It is essential to take a real understanding of the dynamics of micro bubbles and bubble cluster in these applications. Thus we numerically simulate them in ultrasound field in this paper. In the numerical simulation, we consider the thermal behavior inside the bubble and the pressure wave phenomena in the bubble cluster in detail, namely, the evaporation and condensation of liquid at the bubble wall, heat transfer through the bubble wall, diffusion of non-condensable gas inside the bubble and the compressibility of liquid. Initial cluster radius is to 0.5[mm], bubble radius is 1.7[mm], void fraction is 0.1[ambient pressure is 101.3[kPa], temperature is 293[K] and the amplitude of ultrasound is 50[kPa]. We simulate bubble cluster in ultrasound field at various frequencies and we obtain the following conclusions. 1) The maximum pressure inside bubble cluster reaches 5[MPa] and this is much higher than that of a bubble. 2) Bubble cluster behaves like a rigid body acoustically when the frequency of ultrasound is much higher than its natural frequency.

A simple and fast method to determine the parameters for fuzzy c-means cluster analysis

DEFF Research Database (Denmark)

Schwämmle, Veit; Jensen, Ole Nørregaard

2010-01-01

MOTIVATION: Fuzzy c-means clustering is widely used to identify cluster structures in high-dimensional datasets, such as those obtained in DNA microarray and quantitative proteomics experiments. One of its main limitations is the lack of a computationally fast method to set optimal values...... of algorithm parameters. Wrong parameter values may either lead to the inclusion of purely random fluctuations in the results or ignore potentially important data. The optimal solution has parameter values for which the clustering does not yield any results for a purely random dataset but which detects cluster...... formation with maximum resolution on the edge of randomness. RESULTS: Estimation of the optimal parameter values is achieved by evaluation of the results of the clustering procedure applied to randomized datasets. In this case, the optimal value of the fuzzifier follows common rules that depend only...

Enforcing conservation laws in nonequilibrium cluster perturbation theory

Science.gov (United States)

Gramsch, Christian; Potthoff, Michael

2017-05-01

Using the recently introduced time-local formulation of the nonequilibrium cluster perturbation theory (CPT), we construct a generalization of the approach such that macroscopic conservation laws are respected. This is achieved by exploiting the freedom for the choice of the starting point of the all-order perturbation theory in the intercluster hopping. The proposed conserving CPT is a self-consistent propagation scheme which respects the conservation of energy, particle number, and spin, which treats short-range correlations exactly up to the linear scale of the cluster, and which represents a mean-field-like approach on length scales beyond the cluster size. Using Green's functions, conservation laws are formulated as local constraints on the local spin-dependent particle and the doublon density. We consider them as conditional equations to self-consistently fix the time-dependent intracluster one-particle parameters. Thanks to the intrinsic causality of the CPT, this can be set up as a step-by-step time propagation scheme with a computational effort scaling linearly with the maximum propagation time and exponentially in the cluster size. As a proof of concept, we consider the dynamics of the two-dimensional, particle-hole-symmetric Hubbard model following a weak interaction quench by simply employing two-site clusters only. Conservation laws are satisfied by construction. We demonstrate that enforcing them has strong impact on the dynamics. While the doublon density is strongly oscillating within plain CPT, a monotonic relaxation is observed within the conserving CPT.

Carrying capacity of water resources in Bandung Basin

Science.gov (United States)

Marganingrum, D.

2018-02-01

The concept of carrying capacity is widely used in various sectors as a management tool for sustainable development processes. This idea has also been applied in watershed or basin scale. Bandung Basin is the upstream of Citarum watershed known as one of the national strategic areas. This area has developed into a metropolitan area loaded with various environmental problems. Therefore, research that is related to environmental carrying capacity in this area becomes a strategic issue. However, research on environmental carrying capacity that has been done in this area is still partial either in water balance terminology, land suitability, ecological footprint, or balance of supply and demand of resources. This paper describes the application of the concept of integrated environmental carrying capacity in order to overcome the increasing complexity and dynamic environmental problems. The sector that becomes the focus of attention is the issue of water resources. The approach method to be carried out is to combine the concept of maximum balance and system dynamics. The dynamics of the proposed system is the ecological dynamics and population that cannot be separated from one another as a unity of the Bandung Basin ecosystem.

CHARACTERISTICS OF MAXIMUM PERFORMANCE OF PEDALING EXERCISE IN RECUMBENT AND SUPINE POSITIONS

Directory of Open Access Journals (Sweden)

Morimasa Kato

2011-09-01

Full Text Available To determine the characteristics of maximum pedaling performance in the recumbent and supine positions, maximum isokinetic leg muscle strength was measured in eight healthy male subjects during pedaling at three velocities (300°/s, 480°/s, and 660°/s, and maximum incremental tests were performed for each position. The maximum isokinetic muscle strength in the recumbent position was 210.0 ± 29.2 Nm at 300°/s, 158.4 ± 19.8 Nm at 480°/s, and 110.6 ± 13.2 at 660°/s. In contrast, the muscle strength in the supine position was 229.3 ± 36.7 Nm at 300°/s, 180. 7 ± 20.3 Nm at 480°/s, and 129.6 ± 14.0 Nm at 660°/s. Thus, the maximum isokinetic muscle strength showed significantly higher values in the supine position than in the recumbent position at all angular velocities. The knee and hip joint angles were measured at peak torque using a goniometer; the knee joint angle was not significantly different between both positions, whereas the hip joint angle was greater in the supine position than in the recumbent position (Supine position: 137.3 ± 9. 33 degree at 300°/s, 140.0 ± 11.13 degrees at 480°/s, and 141.0 ± 9.61 degrees at 660°/s. Recumbent position: 99.5 ± 12.21 degrees at 300°/s, 101.6 ± 12.29 degrees at 480°/s, and 105.8 ± 14.28 degrees at 660°/s. Peak oxygen uptake was higher in the recumbent position (50.3 ± 4.43 ml·kg-1·min-1 than in the supine position (48.7 ± 5.10 ml·kg-1·min-1. At maximum exertion, the heart rate and whole-body rate of perceived exertion (RPE were unaffected by position, but leg muscle RPE was higher in the supine position (19.5 ± 0.53 than in the recumbent position (18.8 ± 0.71. These results suggest that the supine position is more suitable for muscle strength exertion than the recumbent position, and this may be due to different hip joint angles between the positions. On the contrary, the endurance capacity was higher in the recumbent position than in the supine position. Since leg muscle

Interception storage capacities of tropical rainforest canopy trees

Science.gov (United States)

Herwitz, Stanley R.

1985-04-01

The rainwater interception storage capacities of mature canopy trees in a tropical rainforest site in northeast Queensland, Australia, were approximated using a combination of field and laboratory measurements. The above-ground vegetative surfaces of five selected species (three flaky-barked; two smooth-barked) were saturated under laboratory conditions in order to establish their maximum interception storage capacities. Average leaf surface interception storages ranged from 112 to 161 ml m -2. The interception storages of bark ranged from 0.51 to 0.97 ml cm -3. These standardized interception storages were applied to estimates of leaf surface area and bark volume for 51 mature canopy trees representing the selected species in the field site. The average whole tree interception storage capacities of the five species ranged from 110 to 5281 per tree and 2.2 to 8.3 mm per unit projected crown area. The highly significant interspecific differences in interception storage capacity suggest that both floristic and demographic data are needed in order to accurately calculate a forest-wide interception storage capacity for species-rich tropical rainforest vegetation. Species with large woody surface areas and small projected crown areas are capable of storing the greatest depth equivalents of rainwater under heavy rainfall conditions. In the case of both the flaky-barked and the smooth-barked species, bark accounted for > 50% of the total interception storage capacity under still-air conditions, and > 80% under turbulent air conditions. The emphasis in past interception studies on the role of leaf surfaces in determining the interception storage capacity of a vegetative cover must be modified for tropical rainforests to include the storage capacity provided by the bark tissue on canopy trees.

DESIGN OF STRUCTURAL ELEMENTS IN THE EVENT OF THE PRE-SET RELIABILITY, REGULAR LOAD AND BEARING CAPACITY DISTRIBUTION

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Tamrazyan Ashot Georgievich

2012-10-01

Full Text Available Accurate and adequate description of external influences and of the bearing capacity of the structural material requires the employment of the probability theory methods. In this regard, the characteristic that describes the probability of failure-free operation is required. The characteristic of reliability means that the maximum stress caused by the action of the load will not exceed the bearing capacity. In this paper, the author presents a solution to the problem of calculation of structures, namely, the identification of reliability of pre-set design parameters, in particular, cross-sectional dimensions. If the load distribution pattern is available, employment of the regularities of distributed functions make it possible to find the pattern of distribution of maximum stresses over the structure. Similarly, we can proceed to the design of structures of pre-set rigidity, reliability and stability in the case of regular load distribution. We consider the element of design (a monolithic concrete slab, maximum stress S which depends linearly on load q. Within a pre-set period of time, the probability will not exceed the values according to the Poisson law. The analysis demonstrates that the variability of the bearing capacity produces a stronger effect on relative sizes of cross sections of a slab than the variability of loads. It is therefore particularly important to reduce the coefficient of variation of the load capacity. One of the methods contemplates the truncation of the bearing capacity distribution by pre-culling the construction material.

Chemistry and kinetics of size-selected cobalt cluster cations at thermal energies. I. Reactions with CO

Science.gov (United States)

Guo, B. C.; Kerns, K. P.; Castleman, A. W., Jr.

1992-06-01

The chemistry and kinetics of size-selected Co+n cluster-ion (n=2-8) reactions with CO are studied using a selected ion drift tube affixed with a laser vaporization source operated under well-defined thermal conditions. All reactions studied in the present work are found to be association reactions. Their absolute rate constants, which are determined quantitatively, are found to have a strong dependence on cluster size. Similar to the cases of reactions with many other reactants such as H2 and CH4, Co+4 and Co+5 display a higher reactivity toward the CO molecule than do clusters of neighboring size. The multiple-collision conditions employed in the present work have enabled a determination of the maximum coordination number of CO molecules bound onto each Co+n cluster. It is found that the tetramer tends to bond 12 CO molecules, the pentamer 14 CO, hexamer 16 CO, and so on. The results are interpreted in terms of Lauher's calculation and the polyhedral skeletal electron pair theory. All the measured maximum coordination numbers correlate extremely well with the predictions of these theories, except for the trimer where the measured number is one CO less than the predicted value. The good agreement between experiment and theory enables one to gain some insight into the geometric structure of the clusters. Based on the present findings, the cobalt tetramer cation is interpreted to have a tetrahedral structure, the pentamer a trigonal bipyramid, and the hexamer an octahedral structure. Other cluster structures are also discussed.

Nuclear clustering - a cluster core model study

International Nuclear Information System (INIS)

Paul Selvi, G.; Nandhini, N.; Balasubramaniam, M.

2015-01-01

Nuclear clustering, similar to other clustering phenomenon in nature is a much warranted study, since it would help us in understanding the nature of binding of the nucleons inside the nucleus, closed shell behaviour when the system is highly deformed, dynamics and structure at extremes. Several models account for the clustering phenomenon of nuclei. We present in this work, a cluster core model study of nuclear clustering in light mass nuclei

Dust Evolution in Galaxy Cluster Simulations

Science.gov (United States)

Gjergo, Eda; Granato, Gian Luigi; Murante, Giuseppe; Ragone-Figueroa, Cinthia; Tornatore, Luca; Borgani, Stefano

2018-06-01

We implement a state-of-the-art treatment of the processes affecting the production and Interstellar Medium (ISM) evolution of carbonaceous and silicate dust grains within SPH simulations. We trace the dust grain size distribution by means of a two-size approximation. We test our method on zoom-in simulations of four massive (M200 ≥ 3 × 1014M⊙) galaxy clusters. We predict that during the early stages of assembly of the cluster at z ≳ 3, where the star formation activity is at its maximum in our simulations, the proto-cluster regions are rich in dusty gas. Compared to the case in which only dust production in stellar ejecta is active, if we include processes occurring in the cold ISM,the dust content is enhanced by a factor 2 - 3. However, the dust properties in this stage turn out to be significantly different from those observationally derived for the average Milky Way dust, and commonly adopted in calculations of dust reprocessing. We show that these differences may have a strong impact on the predicted spectral energy distributions. At low redshift in star forming regions our model reproduces reasonably well the trend of dust abundances over metallicity as observed in local galaxies. However we under-produce by a factor of 2 to 3 the total dust content of clusters estimated observationally at low redshift, z ≲ 0.5 using IRAS, Planck and Herschel satellites data. This discrepancy does not subsist by assuming a lower sputtering efficiency, which erodes dust grains in the hot Intracluster Medium (ICM).

Cluster fusion algorithm: application to Lennard-Jones clusters

DEFF Research Database (Denmark)

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

2006-01-01

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......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...... 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...

Cluster fusion algorithm: application to Lennard-Jones clusters

DEFF Research Database (Denmark)

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

2008-01-01

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......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...... 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...

An Enhanced PSO-Based Clustering Energy Optimization Algorithm for Wireless Sensor Network

Directory of Open Access Journals (Sweden)

C. Vimalarani

2016-01-01

Full Text Available Wireless Sensor Network (WSN is a network which formed with a maximum number of sensor nodes which are positioned in an application environment to monitor the physical entities in a target area, for example, temperature monitoring environment, water level, monitoring pressure, and health care, and various military applications. Mostly sensor nodes are equipped with self-supported battery power through which they can perform adequate operations and communication among neighboring nodes. Maximizing the lifetime of the Wireless Sensor networks, energy conservation measures are essential for improving the performance of WSNs. This paper proposes an Enhanced PSO-Based Clustering Energy Optimization (EPSO-CEO algorithm for Wireless Sensor Network in which clustering and clustering head selection are done by using Particle Swarm Optimization (PSO algorithm with respect to minimizing the power consumption in WSN. The performance metrics are evaluated and results are compared with competitive clustering algorithm to validate the reduction in energy consumption.

Confined SnO2 quantum-dot clusters in graphene sheets as high-performance anodes for lithium-ion batteries.

Science.gov (United States)

Zhu, Chengling; Zhu, Shenmin; Zhang, Kai; Hui, Zeyu; Pan, Hui; Chen, Zhixin; Li, Yao; Zhang, Di; Wang, Da-Wei

2016-05-16

Construction of metal oxide nanoparticles as anodes is of special interest for next-generation lithium-ion batteries. The main challenge lies in their rapid capacity fading caused by the structural degradation and instability of solid-electrolyte interphase (SEI) layer during charge/discharge process. Herein, we address these problems by constructing a novel-structured SnO2-based anode. The novel structure consists of mesoporous clusters of SnO2 quantum dots (SnO2 QDs), which are wrapped with reduced graphene oxide (RGO) sheets. The mesopores inside the clusters provide enough room for the expansion and contraction of SnO2 QDs during charge/discharge process while the integral structure of the clusters can be maintained. The wrapping RGO sheets act as electrolyte barrier and conductive reinforcement. When used as an anode, the resultant composite (MQDC-SnO2/RGO) shows an extremely high reversible capacity of 924 mAh g(-1) after 200 cycles at 100 mA g(-1), superior capacity retention (96%), and outstanding rate performance (505 mAh g(-1) after 1000 cycles at 1000 mA g(-1)). Importantly, the materials can be easily scaled up under mild conditions. Our findings pave a new way for the development of metal oxide towards enhanced lithium storage performance.

Analyzing indirect effects in cluster randomized trials. The effect of estimation method, number of groups and group sizes on accuracy and power.

Directory of Open Access Journals (Sweden)

Joop eHox

2014-02-01

Full Text Available Cluster randomized trials assess the effect of an intervention that is carried out at the group or cluster level. Ajzen’s theory of planned behaviour is often used to model the effect of the intervention as an indirect effect mediated in turn by attitude, norms and behavioural intention. Structural equation modelling (SEM is the technique of choice to estimate indirect effects and their significance. However, this is a large sample technique, and its application in a cluster randomized trial assumes a relatively large number of clusters. In practice, the number of clusters in these studies tends to be relatively small, e.g. much less than fifty. This study uses simulation methods to find the lowest number of clusters needed when multilevel SEM is used to estimate the indirect effect. Maximum likelihood estimation is compared to Bayesian analysis, with the central quality criteria being accuracy of the point estimate and the confidence interval. We also investigate the power of the test for the indirect effect. We conclude that Bayes estimation works well with much smaller cluster level sample sizes such as 20 cases than maximum likelihood estimation; although the bias is larger the coverage is much better. When only 5 to 10 clusters are available per treatment condition even with Bayesian estimation problems occur.

Deconstructing Bipolar Disorder and Schizophrenia: A cross-diagnostic cluster analysis of cognitive phenotypes.

Science.gov (United States)

Lee, Junghee; Rizzo, Shemra; Altshuler, Lori; Glahn, David C; Miklowitz, David J; Sugar, Catherine A; Wynn, Jonathan K; Green, Michael F

2017-02-01

Bipolar disorder (BD) and schizophrenia (SZ) show substantial overlap. It has been suggested that a subgroup of patients might contribute to these overlapping features. This study employed a cross-diagnostic cluster analysis to identify subgroups of individuals with shared cognitive phenotypes. 143 participants (68 BD patients, 39 SZ patients and 36 healthy controls) completed a battery of EEG and performance assessments on perception, nonsocial cognition and social cognition. A K-means cluster analysis was conducted with all participants across diagnostic groups. Clinical symptoms, functional capacity, and functional outcome were assessed in patients. A two-cluster solution across 3 groups was the most stable. One cluster including 44 BD patients, 31 controls and 5 SZ patients showed better cognition (High cluster) than the other cluster with 24 BD patients, 35 SZ patients and 5 controls (Low cluster). BD patients in the High cluster performed better than BD patients in the Low cluster across cognitive domains. Within each cluster, participants with different clinical diagnoses showed different profiles across cognitive domains. All patients are in the chronic phase and out of mood episode at the time of assessment and most of the assessment were behavioral measures. This study identified two clusters with shared cognitive phenotype profiles that were not proxies for clinical diagnoses. The finding of better social cognitive performance of BD patients than SZ patients in the Lowe cluster suggest that relatively preserved social cognition may be important to identify disease process distinct to each disorder. Copyright © 2016 Elsevier B.V. All rights reserved.

FRCA: A Fuzzy Relevance-Based Cluster Head Selection Algorithm for Wireless Mobile Ad-Hoc Sensor Networks

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Taegwon Jeong

2011-05-01

Full Text Available Clustering is an important mechanism that efficiently provides information for mobile nodes and improves the processing capacity of routing, bandwidth allocation, and resource management and sharing. Clustering algorithms can be based on such criteria as the battery power of nodes, mobility, network size, distance, speed and direction. Above all, in order to achieve good clustering performance, overhead should be minimized, allowing mobile nodes to join and leave without perturbing the membership of the cluster while preserving current cluster structure as much as possible. This paper proposes a Fuzzy Relevance-based Cluster head selection Algorithm (FRCA to solve problems found in existing wireless mobile ad hoc sensor networks, such as the node distribution found in dynamic properties due to mobility and flat structures and disturbance of the cluster formation. The proposed mechanism uses fuzzy relevance to select the cluster head for clustering in wireless mobile ad hoc sensor networks. In the simulation implemented on the NS-2 simulator, the proposed FRCA is compared with algorithms such as the Cluster-based Routing Protocol (CBRP, the Weighted-based Adaptive Clustering Algorithm (WACA, and the Scenario-based Clustering Algorithm for Mobile ad hoc networks (SCAM. The simulation results showed that the proposed FRCA achieves better performance than that of the other existing mechanisms.

FRCA: a fuzzy relevance-based cluster head selection algorithm for wireless mobile ad-hoc sensor networks.

Science.gov (United States)

Lee, Chongdeuk; Jeong, Taegwon

2011-01-01

Clustering is an important mechanism that efficiently provides information for mobile nodes and improves the processing capacity of routing, bandwidth allocation, and resource management and sharing. Clustering algorithms can be based on such criteria as the battery power of nodes, mobility, network size, distance, speed and direction. Above all, in order to achieve good clustering performance, overhead should be minimized, allowing mobile nodes to join and leave without perturbing the membership of the cluster while preserving current cluster structure as much as possible. This paper proposes a Fuzzy Relevance-based Cluster head selection Algorithm (FRCA) to solve problems found in existing wireless mobile ad hoc sensor networks, such as the node distribution found in dynamic properties due to mobility and flat structures and disturbance of the cluster formation. The proposed mechanism uses fuzzy relevance to select the cluster head for clustering in wireless mobile ad hoc sensor networks. In the simulation implemented on the NS-2 simulator, the proposed FRCA is compared with algorithms such as the Cluster-based Routing Protocol (CBRP), the Weighted-based Adaptive Clustering Algorithm (WACA), and the Scenario-based Clustering Algorithm for Mobile ad hoc networks (SCAM). The simulation results showed that the proposed FRCA achieves better performance than that of the other existing mechanisms.

Generating clustered scale-free networks using Poisson based localization of edges

Science.gov (United States)

Türker, İlker

2018-05-01

We introduce a variety of network models using a Poisson-based edge localization strategy, which result in clustered scale-free topologies. We first verify the success of our localization strategy by realizing a variant of the well-known Watts-Strogatz model with an inverse approach, implying a small-world regime of rewiring from a random network through a regular one. We then apply the rewiring strategy to a pure Barabasi-Albert model and successfully achieve a small-world regime, with a limited capacity of scale-free property. To imitate the high clustering property of scale-free networks with higher accuracy, we adapted the Poisson-based wiring strategy to a growing network with the ingredients of both preferential attachment and local connectivity. To achieve the collocation of these properties, we used a routine of flattening the edges array, sorting it, and applying a mixing procedure to assemble both global connections with preferential attachment and local clusters. As a result, we achieved clustered scale-free networks with a computational fashion, diverging from the recent studies by following a simple but efficient approach.

Cluster analysis technique for assessing variability in cowpea (Vigna unguiculata L. Walp accessions from Nigeria

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Ajayi Abiola Toyin

2013-01-01

Full Text Available The genetic variability among 10 accessions of cowpea, Vigna unguiculata (L. Walp was studied by the use of 13 qualitative and 13 quantitative traits. From the results on qualitative traits, dendrogram grouped the 10 accessions into two major clusters, 1 and 2.Cluster 1 had 3 accessions and cluster 2 had 2 sub-clusters (I and II, having 2 accessions in sub-cluster I and 5 accessions in sub-cluster II. The dendrogram revealed two major clusters, 1 and 2, for quantitative data, for the 10 accessions. At distance of 4 and 6, cluster 1 had two sub-clusters (I and II, with sub-cluster I having 5 accessions, sub-cluster II having 4 accessions while cluster 2 had only 1 accession. This study made the observation that identification of the right agro-morphological traits of high discriminating capacity is essential, before embarking on any genetic diversity; as it was revealed that some traits discriminated more efficiently among the accessions than others. A group of accessions, which are NGSA1, NGSA2, NGSA3, NGSA4, NGSA7, NGSA9 and NGSA10, was identified as being different from the others for number of seeds per pod, pod length, plant height, peduncle length, seed weight and number of pods per plant. These accessions may be good for cowpea improvement programs.

STAR FORMATION IN DENSE CLUSTERS

International Nuclear Information System (INIS)

Myers, Philip C.

2011-01-01

A model of core-clump accretion with equally likely stopping describes star formation in the dense parts of clusters, where models of isolated collapsing cores may not apply. Each core accretes at a constant rate onto its protostar, while the surrounding clump gas accretes as a power of protostar mass. Short accretion flows resemble Shu accretion and make low-mass stars. Long flows resemble reduced Bondi accretion and make massive stars. Accretion stops due to environmental processes of dynamical ejection, gravitational competition, and gas dispersal by stellar feedback, independent of initial core structure. The model matches the field star initial mass function (IMF) from 0.01 to more than 10 solar masses. The core accretion rate and the mean accretion duration set the peak of the IMF, independent of the local Jeans mass. Massive protostars require the longest accretion durations, up to 0.5 Myr. The maximum protostar luminosity in a cluster indicates the mass and age of its oldest protostar. The distribution of protostar luminosities matches those in active star-forming regions if protostars have a constant birthrate but not if their births are coeval. For constant birthrate, the ratio of young stellar objects to protostars indicates the star-forming age of a cluster, typically ∼1 Myr. The protostar accretion luminosity is typically less than its steady spherical value by a factor of ∼2, consistent with models of episodic disk accretion.

Case Study: Physical Capacity and Nutritional Status Before and After a Single-Handed Yacht Race.

Science.gov (United States)

Ghiani, Giovanna; Magnani, Sara; Doneddu, Azzurra; Sainas, Gianmarco; Pinna, Virginia; Caboi, Marco; Palazzolo, Girolamo; Tocco, Filippo; Crisafulli, Antonio

2017-12-18

During solitary sailing the sailor is exposed to sleep deprivation and difficulties in consuming regular meals. Sailor weight loss is often reported. In the present case study we describe changes in the physical capacity and the nutritional status of an athlete attempting a single-handed yacht race around the globe. An Italian male ocean racer (GM) asked for our help to reach an optimum level of physical and nutritional preparation. We planned his diet after assessing his anthropometric parameters and body composition as well as his usual energy intake and nutritional expenditure. The diet consisted in 120 meals stored in sealed plastic bags. Before his departure, GM performed two incremental exercise tests (cycle- and arm crank- ergometry) to assess his physical capacity. Cardiac functions were also estimated by Doppler echocardiography. All measures and exercise tests were repeated 10 days after GM finished the race, which lasted 64 days. Anthropometric measures did not change significantly, with the exception of Arm Fat Area and Thigh Muscle area, which decreased. There were evident increments in maximum oxygen intake and maximum workload during arm cranking after the race. On the contrary, maximum oxygen uptake and maximum workload decreased during cycling. Finally, End Diastolic and Stroke Volume decreased after the race. It was concluded that nutritional counseling was useful to avoid excessive changes in the nutritional status and body composition due to 64 days of solitary navigation. However, a reduction in physical leg capacity and cardiovascular functions secondary to legs disuse were present.

FTUC: A Flooding Tree Uneven Clustering Protocol for a Wireless Sensor Network.

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He, Wei; Pillement, Sebastien; Xu, Du

2017-11-23

Clustering is an efficient approach in a wireless sensor network (WSN) to reduce the energy consumption of nodes and to extend the lifetime of the network. Unfortunately, this approach requires that all cluster heads (CHs) transmit their data to the base station (BS), which gives rise to the long distance communications problem, and in multi-hop routing, the CHs near the BS have to forward data from other nodes that lead those CHs to die prematurely, creating the hot zones problem. Unequal clustering has been proposed to solve these problems. Most of the current algorithms elect CH only by considering their competition radius, leading to unevenly distributed cluster heads. Furthermore, global distances values are needed when calculating the competition radius, which is a tedious task in large networks. To face these problems, we propose a flooding tree uneven clustering protocol (FTUC) suited for large networks. Based on the construction of a tree type sub-network to calculate the minimum and maximum distances values of the network, we then apply the unequal cluster theory. We also introduce referenced position circles to evenly elect cluster heads. Therefore, cluster heads are elected depending on the node's residual energy and their distance to a referenced circle. FTUC builds the best inter-cluster communications route by evaluating a cluster head cost function to find the best next hop to the BS. The simulation results show that the FTUC algorithm decreases the energy consumption of the nodes and balances the global energy consumption effectively, thus extending the lifetime of the network.

Contextual Learning Induces Dendritic Spine Clustering in Retrosplenial Cortex

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Adam C Frank

2014-03-01

Full Text Available Molecular and electrophysiological studies find convergent evidence suggesting that plasticity within a dendritic tree is not randomly dispersed, but rather clustered into functional groups. Further, results from in silico neuronal modeling show that clustered plasticity is able to increase storage capacity 45 times compared to dispersed plasticity. Recent in vivo work utilizing chronic 2-photon microscopy tested the clustering hypothesis and showed that repetitive motor learning is able to induce clustered addition of new dendritic spines on apical dendrites of L5 neurons in primary motor cortex; moreover, clustered spines were found to be more stable than non-clustered spines, suggesting a physiological role for spine clustering. To further test this hypothesis we used in vivo 2-photon imaging in Thy1-YFP-H mice to chronically examine dendritic spine dynamics in retrosplenial cortex (RSC during spatial learning. RSC is a key component of an extended spatial learning and memory circuit that includes hippocampus and entorhinal cortex. Importantly, RSC is known from both lesion and immediate early gene studies to be critically involved in spatial learning and more specifically in contextual fear conditioning. We utilized a modified contextual fear conditioning protocol wherein animals received a mild foot shock each day for five days; this protocol induces gradual increases in context freezing over several days before the animals reach a behavioral plateau. We coupled behavioral training with four separate in vivo imaging sessions, two before training begins, one early in training, and a final session after training is complete. This allowed us to image spine dynamics before training as well as early in learning and after animals had reached behavioral asymptote. We find that this contextual learning protocol induces a statistically significant increase in the formation of clusters of new dendritic spines in trained animals when compared to home

Maximum permissible dose

International Nuclear Information System (INIS)

Anon.

1979-01-01

This chapter presents a historic overview of the establishment of radiation guidelines by various national and international agencies. The use of maximum permissible dose and maximum permissible body burden limits to derive working standards is discussed

A ROBUST CLUSTER HEAD SELECTION BASED ON NEIGHBORHOOD CONTRIBUTION AND AVERAGE MINIMUM POWER FOR MANETs

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S.Balaji

2015-06-01

Full Text Available Mobile Adhoc network is an instantaneous wireless network that is dynamic in nature. It supports single hop and multihop communication. In this infrastructure less network, clustering is a significant model to maintain the topology of the network. The clustering process includes different phases like cluster formation, cluster head selection, cluster maintenance. Choosing cluster head is important as the stability of the network depends on well-organized and resourceful cluster head. When the node has increased number of neighbors it can act as a link between the neighbor nodes which in further reduces the number of hops in multihop communication. Promisingly the node with more number of neighbors should also be available with enough energy to provide stability in the network. Hence these aspects demand the focus. In weight based cluster head selection, closeness and average minimum power required is considered for purging the ineligible nodes. The optimal set of nodes selected after purging will compete to become cluster head. The node with maximum weight selected as cluster head. Mathematical formulation is developed to show the proposed method provides optimum result. It is also suggested that weight factor in calculating the node weight should give precise importance to energy and node stability.

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.

Cluster-Based Adaptation Using Density Forest for HMM Phone Recognition

DEFF Research Database (Denmark)

Abou-Zleikha, Mohamed; Tan, Zheng-Hua; Christensen, Mads Græsbøll

2014-01-01

The dissimilarity between the training and test data in speech recognition systems is known to have a considerable effect on the recognition accuracy. To solve this problem, we use density forest to cluster the data and use maximum a posteriori (MAP) method to build a cluster-based adapted Gaussian...... mixture models (GMMs) in HMM speech recognition. Specifically, a set of bagged versions of the training data for each state in the HMM is generated, and each of these versions is used to generate one GMM and one tree in the density forest. Thereafter, an acoustic model forest is built by replacing...... the data of each leaf (cluster) in each tree with the corresponding GMM adapted by the leaf data using the MAP method. The results show that the proposed approach achieves 3:8% (absolute) lower phone error rate compared with the standard HMM/GMM and 0:8% (absolute) lower PER compared with bagged HMM/GMM....

Micron-size hydrogen cluster target for laser-driven proton acceleration

Science.gov (United States)

Jinno, S.; Kanasaki, M.; Uno, M.; Matsui, R.; Uesaka, M.; Kishimoto, Y.; Fukuda, Y.

2018-04-01

As a new laser-driven ion acceleration technique, we proposed a way to produce impurity-free, highly reproducible, and robust proton beams exceeding 100 MeV using a Coulomb explosion of micron-size hydrogen clusters. In this study, micron-size hydrogen clusters were generated by expanding the cooled high-pressure hydrogen gas into a vacuum via a conical nozzle connected to a solenoid valve cooled by a mechanical cryostat. The size distributions of the hydrogen clusters were evaluated by measuring the angular distribution of laser light scattered from the clusters. The data were analyzed mathematically based on the Mie scattering theory combined with the Tikhonov regularization method. The maximum size of the hydrogen cluster at 25 K and 6 MPa in the stagnation state was recognized to be 2.15 ± 0.10 μm. The mean cluster size decreased with increasing temperature, and was found to be much larger than that given by Hagena’s formula. This discrepancy suggests that the micron-size hydrogen clusters were formed by the atomization (spallation) of the liquid or supercritical fluid phase of hydrogen. In addition, the density profiles of the gas phase were evaluated for 25 to 80 K at 6 MPa using a Nomarski interferometer. Based on the measurement results and the equation of state for hydrogen, the cluster mass fraction was obtained. 3D particles-in-cell (PIC) simulations concerning the interaction processes of micron-size hydrogen clusters with high power laser pulses predicted the generation of protons exceeding 100 MeV and accelerating in a laser propagation direction via an anisotropic Coulomb explosion mechanism, thus demonstrating a future candidate in laser-driven proton sources for upcoming multi-petawatt lasers.

Enhanced load-carrying capacity of hairy surfaces floating on water.

Science.gov (United States)

Xue, Yahui; Yuan, Huijing; Su, Weidong; Shi, Yipeng; Duan, Huiling

2014-05-08

Water repellency of hairy surfaces depends on the geometric arrangement of these hairs and enables different applications in both nature and engineering. We investigate the mechanism and optimization of a hairy surface floating on water to obtain its maximum load-carrying capacity by the free energy and force analyses. It is demonstrated that there is an optimum cylinder spacing, as a result of the compromise between the vertical capillary force and the gravity, so that the hairy surface has both high load-carrying capacity and mechanical stability. Our analysis makes it clear that the setae on water striders' legs or some insects' wings are in such an optimized geometry. Moreover, it is shown that surface hydrophobicity can further increase the capacity of a hairy surface with thick cylinders, while the influence is negligible when the cylinders are thin.

Storage Capacity and Sedimentation of Loch Lomond Reservoir, Santa Cruz, California, 1998

Science.gov (United States)

McPherson, Kelly R.; Harmon, Jerry G.

2000-01-01

In 1998, a bathymetric survey was done to determine the storage capacity and the loss of capacity owing to sedimentation of Loch Lomond Reservoir in Santa Cruz County, California. Results of the survey indicate that the maximum capacity of the reservoir is 8,991 acre-feet in November 1998. The results of previous investigations indicate that storage capacity of the reservoir is less than 8,991 acre-feet. The storage capacity determined from those investigations probably were underestimated because of limitations of the methods and the equipment used. The volume of sedimentation in a reservoir is considered equal to the decrease in storage capacity. To determine sedimentation in Loch Lomond Reservoir, change in storage capacity was estimated for an upstream reach of the reservoir. The change in storage capacity was determined by comparing a 1998 thalweg profile (valley floor) of the reservoir with thalweg profiles from previous investigations; results of the comparison indicate that sedimentation is occurring in the upstream reach. Cross sections for 1998 and 1982 were compared to determine the magnitude of sedimentation in the upstream reach of the reservoir. Results of the comparison, which were determined from changes in the cross-sectional areas, indicate that the capacity of the reservoir decreased by 55 acre-feet.

Structural integrity of rod cluster control assembly of Chashma Nuclear Power Plant -1

International Nuclear Information System (INIS)

Siddiqui, A.; Zafar, F.; Murtaza, G.

2008-01-01

This study has been made in an attempt to verify the structural integrity of Rod Cluster Control Assembly (RCCA) of Chashma Nuclear Power Plant-1(CHASNUPP-1) using ANSYS computer code. The CHASNUPP-1 (PWR type, 300 MWe capacity, unit 1) was built by China at Chashma (District Mianwali), Pakistan. The plant is successfully operating since 2000. The rod cluster control assemblies (RCCA) are used to control fast reactivity changes in PWR type reactors during the normal operation and accident conditions. To fulfill this function the RCCA is stepped upwards or downwards by control rod drive mechanism (CRDM). The stepping action produces a large amount of acceleration. The load produced during stepping is normally considered as limiting one. In this work we have considered the experimental results of a test conducted in China. The test was performed to measure the acceleration produced in upward and downward stepping by CRDM on RCCA, at room temperatures, both in air and static water. The test results showed acceleration (g, m/s 2 ) values, 10.8 - 51.0 and 46.4 - 78.0, in air and static water environments, respectively. Making the analysis on conservative side we selected the highest value of acceleration, 78 g, for our study. To ensure the structural strength, a finite element model of CHASNUPP-1 RCCA has been developed simulating the loading conditions prevailing during reactor operation. This model has been analyzed using the Finite Element Code. The Maximum Stress intensity obtained through this analysis, 186 MPa, is less than the yield stress of RCCA material (∼SS 321), 205 MPa, thus fulfills its structural integrity criteria. (authors)

Cluster-cluster correlations and constraints on the correlation hierarchy

Science.gov (United States)

Hamilton, A. J. S.; Gott, J. R., III

1988-01-01

The hypothesis that galaxies cluster around clusters at least as strongly as they cluster around galaxies imposes constraints on the hierarchy of correlation amplitudes in hierachical clustering models. The distributions which saturate these constraints are the Rayleigh-Levy random walk fractals proposed by Mandelbrot; for these fractal distributions cluster-cluster correlations are all identically equal to galaxy-galaxy correlations. If correlation amplitudes exceed the constraints, as is observed, then cluster-cluster correlations must exceed galaxy-galaxy correlations, as is observed.

CONSTRAINING CLUSTER PHYSICS WITH THE SHAPE OF X-RAY CLUSTERS: COMPARISON OF LOCAL X-RAY CLUSTERS VERSUS ΛCDM CLUSTERS

International Nuclear Information System (INIS)

Lau, Erwin T.; Nagai, Daisuke; Kravtsov, Andrey V.; Vikhlinin, Alexey; Zentner, Andrew R.

2012-01-01

Recent simulations of cluster formation have demonstrated that condensation of baryons into central galaxies during cluster formation can drive the shape of the gas distribution in galaxy clusters significantly rounder out to their virial radius. These simulations generally predict stellar fractions within cluster virial radii that are ∼2-3 times larger than the stellar masses deduced from observations. In this paper, we compare ellipticity profiles of simulated clusters performed with varying input physics (radiative cooling, star formation, and supernova feedback) to the cluster ellipticity profiles derived from Chandra and ROSAT observations, in an effort to constrain the fraction of gas that cools and condenses into the central galaxies within clusters. We find that local relaxed clusters have an average ellipticity of ε = 0.18 ± 0.05 in the radial range of 0.04 ≤ r/r 500 ≤ 1. At larger radii r > 0.1r 500 , the observed ellipticity profiles agree well with the predictions of non-radiative simulations. In contrast, the ellipticity profiles of simulated clusters that include dissipative gas physics deviate significantly from the observed ellipticity profiles at all radii. The dissipative simulations overpredict (underpredict) ellipticity in the inner (outer) regions of galaxy clusters. By comparing simulations with and without dissipative gas physics, we show that gas cooling causes the gas distribution to be more oblate in the central regions, but makes the outer gas distribution more spherical. We find that late-time gas cooling and star formation are responsible for the significantly oblate gas distributions in cluster cores, but the gas shapes outside of cluster cores are set primarily by baryon dissipation at high redshift (z ≥ 2). Our results indicate that the shapes of X-ray emitting gas in galaxy clusters, especially at large radii, can be used to place constraints on cluster gas physics, making it potential probes of the history of baryonic

Climate controls photosynthetic capacity more than leaf nitrogen contents

Science.gov (United States)

Ali, A. A.; Xu, C.; McDowell, N. G.

2013-12-01

Global vegetation models continue to lack the ability to make reliable predictions because the photosynthetic capacity varies a lot with growth conditions, season and among species. It is likely that vegetation models link photosynthetic capacity to concurrent changes in leaf nitrogen content only. To improve the predictions of the vegetation models, there is an urgent need to review species growth conditions and their seasonal response to changing climate. We sampled the global distribution of the Vcmax (maximum carboxylation rates) data of various species across different environmental gradients from the literature and standardized its value to 25 degree Celcius. We found that species explained the largest variation in (1) the photosynthetic capacity and (2) the proportion of nitrogen allocated for rubisco (PNcb). Surprisingly, climate variables explained more variations in photosynthetic capacity as well as PNcb than leaf nitrogen content and/or specific leaf area. The chief climate variables that explain variation in photosynthesis and PNcb were radiation, temperature and daylength. Our analysis suggests that species have the greatest control over photosynthesis and PNcb. Further, compared to leaf nitrogen content and/or specific leaf area, climate variables have more control over photosynthesis and PNcb. Therefore, climate variables should be incorporated in the global vegetation models when making predictions about the photosynthetic capacity.

Catalytic activity of Cu4-cluster to adsorb H2S gas: h-BN nanosheet

Science.gov (United States)

Kansara, Shivam; Gupta, Sanjeev K.; Sonvane, Yogesh

2018-05-01

We have investigated the electronic properties, adsorptions strength and charge transfer using first principles calculations using density functional theory (DFT). The hexagonal boron nitride (h-BN) substrate shows metallic behavior, which helps to enhance the absorption process. The adsorption of three different orientations (S, D and T) of the H2S gas molecules to analyze the maximum adsorption strength from them onto a copper cluster (Cu4) based on h-BN nanosheet. The maximum adsorption energy of the H2S gas molecule is -1.50 eV for the S orientation and for D and U, it is -0.71 eV and -0.78 eV, respectively. The results show that Cu4 cluster helps to capture H2S gas from the environment and results are useful for the cleaning environment from the toxic gases.

The System-Supplementing Effect of the Interaction between Innovative Capacity and Institutional Environment Factors of a Region

Directory of Open Access Journals (Sweden)

Viktor Nikolayevich Ovchinnikov

2016-06-01

Full Text Available In the article, the effect of interaction between the development level of regional innovative capacity and its innovative and institutional infrastructure is traced. The research objective is to prove the hypothesis of the essential impact of the regional institutional and information environment on its innovative capacity, the identification of the effect of their systemsupplementing interaction. From the standpoint of the methodology of system-structural research its components are allocated within the innovative capacity of the regional innovative system (RIS, they are presented by a corporate sector, the structures of small and medium business, and also by the subjects of ethnic economy. The use of essential-analytical and functional approaches has revealed the leading role of intangible assets of the corporate sector of the economy in region’s innovative development. The correlation and regression analysis has confirmed the essential dependence of the innovative activity of the region on the systemic completeness of the development of its institutional and infrastructure environment. The results of the research have shown that to ensure the system-supplementing effect of the interaction between innovative capacity and the factors of its activation in the sphere of institutional infrastructure, it is necessary to consistently develop its operational base — the institutions of RIS. The recommendations reasoned in the article may be used for the development of regional innovation strategies, the formation of innovation clusters. The three-component structure of the innovation cluster of the region is offered; its integrating function in relation to the innovative components of the regional sectoral clusters is determined. The factors constraining the growth of innovation activity of the regional economic subjects are revealed and the recommendations on the development of the institutional and infrastructural environment of the Rostov

3.5D dynamic PET image reconstruction incorporating kinetics-based clusters

International Nuclear Information System (INIS)

Lu Lijun; Chen Wufan; Karakatsanis, Nicolas A; Rahmim, Arman; Tang Jing

2012-01-01

Standard 3D dynamic positron emission tomographic (PET) imaging consists of independent image reconstructions of individual frames followed by application of appropriate kinetic model to the time activity curves at the voxel or region-of-interest (ROI). The emerging field of 4D PET reconstruction, by contrast, seeks to move beyond this scheme and incorporate information from multiple frames within the image reconstruction task. Here we propose a novel reconstruction framework aiming to enhance quantitative accuracy of parametric images via introduction of priors based on voxel kinetics, as generated via clustering of preliminary reconstructed dynamic images to define clustered neighborhoods of voxels with similar kinetics. This is then followed by straightforward maximum a posteriori (MAP) 3D PET reconstruction as applied to individual frames; and as such the method is labeled ‘3.5D’ image reconstruction. The use of cluster-based priors has the advantage of further enhancing quantitative performance in dynamic PET imaging, because: (a) there are typically more voxels in clusters than in conventional local neighborhoods, and (b) neighboring voxels with distinct kinetics are less likely to be clustered together. Using realistic simulated 11 C-raclopride dynamic PET data, the quantitative performance of the proposed method was investigated. Parametric distribution-volume (DV) and DV ratio (DVR) images were estimated from dynamic image reconstructions using (a) maximum-likelihood expectation maximization (MLEM), and MAP reconstructions using (b) the quadratic prior (QP-MAP), (c) the Green prior (GP-MAP) and (d, e) two proposed cluster-based priors (CP-U-MAP and CP-W-MAP), followed by graphical modeling, and were qualitatively and quantitatively compared for 11 ROIs. Overall, the proposed dynamic PET reconstruction methodology resulted in substantial visual as well as quantitative accuracy improvements (in terms of noise versus bias performance) for parametric DV

Astrometric and photometric study of the open cluster NGC 2323

Directory of Open Access Journals (Sweden)

Amin M.Y.

2017-01-01

Full Text Available We present a study of the open cluster NGC 2323 using astrometric and photometric data. In our study we used two methods that are able to separate open cluster’s stars from those that belong to the stellar background. Our results of calculations by these two methods indicate that: 1 according to the membership probability, NGC 2323 should contain 497 stars, 2 the cluster center should be at 07h 02m 48.s02 and -08° 20' 17''74,3 the limiting radius of NGC 2323 is 2.31 ± 0.04 pc, the surface number density at this radius is 98.16 stars pc −2, 4 the magnitude function has a maximum at about mv = 14 mag, 5 the total mass of NGC 2323 is estimated dynamically by using astrometric data to be 890 M_, and statistically by using photometric data to be 900 M_, and 6 the distance and age of the cluster are found to be equal to 900 ± 100 pc, and 140 ± 20 Myr, respectively. Finally the dynamical evolution parameter τ of the cluster is about 436.2.

Evolutionary History Underlies Plant Physiological Responses to Global Change Since the Last Glacial Maximum

Science.gov (United States)

Becklin, K. M.; Medeiros, J. S.; Sale, K. R.; Ward, J. K.

2014-12-01

Assessing family and species-level variation in physiological responses to global change across geologic time is critical for understanding factors that underlie changes in species distributions and community composition. Ancient plant specimens preserved within packrat middens are invaluable in this context since they allow for comparisons between co-occurring plant lineages. Here we used modern and ancient plant specimens preserved within packrat middens from the Snake Range, NV to investigate the physiological responses of a mixed montane conifer community to global change since the last glacial maximum. We used a conceptual model to infer relative changes in stomatal conductance and maximum photosynthetic capacity from measures of leaf carbon isotopes, stomatal characteristics, and leaf nitrogen content. Our results indicate that most of the sampled taxa decreased stomatal conductance and/or photosynthetic capacity from glacial to modern times. However, plant families differed in the timing and magnitude of these physiological responses. Additionally, leaf-level responses were more similar within plant families than within co-occurring species assemblages. This suggests that adaptation at the level of leaf physiology may not be the main determinant of shifts in community composition, and that plant evolutionary history may drive physiological adaptation to global change over recent geologic time.

Processing ARM VAP data on an AWS cluster

Science.gov (United States)

Martin, T.; Macduff, M.; Shippert, T.

2017-12-01

The Atmospheric Radiation Measurement (ARM) Data Management Facility (DMF) manages over 18,000 processes and 1.3 TB of data each day. This includes many Value Added Products (VAPs) that make use of multiple instruments to produce the derived products that are scientifically relevant. A thermodynamic and cloud profile VAP is being developed to provide input to the ARM Large-eddy simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) project (https://www.arm.gov/capabilities/vaps/lasso-122) . This algorithm is CPU intensive and the processing requirements exceeded the available DMF computing capacity. Amazon Web Service (AWS) along with CfnCluster was investigated to see how it would perform. This cluster environment is cost effective and scales dynamically based on demand. We were able to take advantage of autoscaling which allowed the cluster to grow and shrink based on the size of the processing queue. We also were able to take advantage of the Amazon Web Services spot market to further reduce the cost. Our test was very successful and found that cloud resources can be used to efficiently and effectively process time series data. This poster will present the resources and methodology used to successfully run the algorithm.

A Unified Simulation Approach for the Fast Outage Capacity Evaluation over Generalized Fading Channels

KAUST Repository

Rached, Nadhir B.; Kammoun, Abla; Alouini, Mohamed-Slim; Tempone, Raul

2016-01-01

The outage capacity (OC) is among the most important performance metrics of communication systems over fading channels. The evaluation of the OC, when equal gain combining (EGC) or maximum ratio combining (MRC) diversity techniques are employed

Oriented cluster perforating technology and its application in horizontal wells

Directory of Open Access Journals (Sweden)

Huabin Chen

2016-11-01

Full Text Available An oriented cluster perforating technology, which integrates both advantages of cluster and oriented perforating, will help solve a series of technical complexities in horizontal well drilling. For realizing its better application in oil and gas development, a series of technologies were developed including perforator self-weight eccentricity, matching of the electronic selective module codes with the surface program control, axial centralized contact signal transmission, and post-perforation intercluster sealing insulation. In this way, the following functions could be realized, such as cable-transmission horizontal well perforator self-weight orientation, dynamic signal transmission, reliable addressing & selective perforation and post-perforation intercluster sealing. The combined perforation and bridge plug or the multi-cluster perforation can be fulfilled in one trip of perforation string. As a result, the horizontal-well oriented cluster perforating technology based on cable conveying was developed. This technology was successfully applied in unconventional gas reservoir exploitation, such as shale gas and coalbed methane, with accurate orientation, reliable selective perforation and satisfactory inter-cluster sealing. The horizontal-well oriented cluster perforating technology benefits the orientation of horizontal well drilling with a definite target and direction, which provides a powerful support for the subsequent reservoir stimulation. It also promotes the fracturing fluid to sweep the principal pay zones to the maximum extent. Moreover, it is conductive to the formation of complex fracture networks in the reservoirs, making quality and efficient development of unconventional gas reservoirs possible.

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

Discovery of path nearby clusters in spatial networks

KAUST Repository

Shang, Shuo

2015-06-01

The discovery of regions of interest in large cities is an important challenge. We propose and investigate a novel query called the path nearby cluster (PNC) query that finds regions of potential interest (e.g., sightseeing places and commercial districts) with respect to a user-specified travel route. Given a set of spatial objects O (e.g., POIs, geo-tagged photos, or geo-tagged tweets) and a query route q , if a cluster c has high spatial-object density and is spatially close to q , it is returned by the query (a cluster is a circular region defined by a center and a radius). This query aims to bring important benefits to users in popular applications such as trip planning and location recommendation. Efficient computation of the PNC query faces two challenges: how to prune the search space during query processing, and how to identify clusters with high density effectively. To address these challenges, a novel collective search algorithm is developed. Conceptually, the search process is conducted in the spatial and density domains concurrently. In the spatial domain, network expansion is adopted, and a set of vertices are selected from the query route as expansion centers. In the density domain, clusters are sorted according to their density distributions and they are scanned from the maximum to the minimum. A pair of upper and lower bounds are defined to prune the search space in the two domains globally. The performance of the PNC query is studied in extensive experiments based on real and synthetic spatial data. © 2014 IEEE.

Relationship Between Non-invasive Brain Stimulation-induced Plasticity and Capacity for Motor Learning.

Science.gov (United States)

López-Alonso, Virginia; Cheeran, Binith; Fernández-del-Olmo, Miguel

2015-01-01

Cortical plasticity plays a key role in motor learning (ML). Non-invasive brain stimulation (NIBS) paradigms have been used to modulate plasticity in the human motor cortex in order to facilitate ML. However, little is known about the relationship between NIBS-induced plasticity over M1 and ML capacity. NIBS-induced MEP changes are related to ML capacity. 56 subjects participated in three NIBS (paired associative stimulation, anodal transcranial direct current stimulation and intermittent theta-burst stimulation), and in three lab-based ML task (serial reaction time, visuomotor adaptation and sequential visual isometric pinch task) sessions. After clustering the patterns of response to the different NIBS protocols, we compared the ML variables between the different patterns found. We used regression analysis to explore further the relationship between ML capacity and summary measures of the MEPs change. We ran correlations with the "responders" group only. We found no differences in ML variables between clusters. Greater response to NIBS protocols may be predictive of poor performance within certain blocks of the VAT. "Responders" to AtDCS and to iTBS showed significantly faster reaction times than "non-responders." However, the physiological significance of these results is uncertain. MEP changes induced in M1 by PAS, AtDCS and iTBS appear to have little, if any, association with the ML capacity tested with the SRTT, the VAT and the SVIPT. However, cortical excitability changes induced in M1 by AtDCS and iTBS may be related to reaction time and retention of newly acquired skills in certain motor learning tasks. Copyright © 2015 Elsevier Inc. All rights reserved.

Parallel clustering algorithm for large-scale biological data sets.

Science.gov (United States)

Wang, Minchao; Zhang, Wu; Ding, Wang; Dai, Dongbo; Zhang, Huiran; Xie, Hao; Chen, Luonan; Guo, Yike; Xie, Jiang

2014-01-01

Recent explosion of biological data brings a great challenge for the traditional clustering algorithms. With increasing scale of data sets, much larger memory and longer runtime are required for the cluster identification problems. The affinity propagation algorithm outperforms many other classical clustering algorithms and is widely applied into the biological researches. However, the time and space complexity become a great bottleneck when handling the large-scale data sets. Moreover, the similarity matrix, whose constructing procedure takes long runtime, is required before running the affinity propagation algorithm, since the algorithm clusters data sets based on the similarities between data pairs. Two types of parallel architectures are proposed in this paper to accelerate the similarity matrix constructing procedure and the affinity propagation algorithm. The memory-shared architecture is used to construct the similarity matrix, and the distributed system is taken for the affinity propagation algorithm, because of its large memory size and great computing capacity. An appropriate way of data partition and reduction is designed in our method, in order to minimize the global communication cost among processes. A speedup of 100 is gained with 128 cores. The runtime is reduced from serval hours to a few seconds, which indicates that parallel algorithm is capable of handling large-scale data sets effectively. The parallel affinity propagation also achieves a good performance when clustering large-scale gene data (microarray) and detecting families in large protein superfamilies.

Application of microarray analysis on computer cluster and cloud platforms.

Science.gov (United States)

Bernau, C; Boulesteix, A-L; Knaus, J

2013-01-01

Analysis of recent high-dimensional biological data tends to be computationally intensive as many common approaches such as resampling or permutation tests require the basic statistical analysis to be repeated many times. A crucial advantage of these methods is that they can be easily parallelized due to the computational independence of the resampling or permutation iterations, which has induced many statistics departments to establish their own computer clusters. An alternative is to rent computing resources in the cloud, e.g. at Amazon Web Services. In this article we analyze whether a selection of statistical projects, recently implemented at our department, can be efficiently realized on these cloud resources. Moreover, we illustrate an opportunity to combine computer cluster and cloud resources. In order to compare the efficiency of computer cluster and cloud implementations and their respective parallelizations we use microarray analysis procedures and compare their runtimes on the different platforms. Amazon Web Services provide various instance types which meet the particular needs of the different statistical projects we analyzed in this paper. Moreover, the network capacity is sufficient and the parallelization is comparable in efficiency to standard computer cluster implementations. Our results suggest that many statistical projects can be efficiently realized on cloud resources. It is important to mention, however, that workflows can change substantially as a result of a shift from computer cluster to cloud computing.

Application of a DC–DC boost converter with maximum power point tracking for low power thermoelectric generators

International Nuclear Information System (INIS)

Mamur, Hayati; Ahiska, Rasit

2015-01-01

Highlights: • Charges with direct and MPPT conditions have been compared. • Perturb and observation method has been practically tested on a new TEG. • Matched load condition has been experimentally investigated. • To increase the efficiency of a TEG, the charge with MPPT should be used. • The charge with MPPT provides twice-fold increase in efficiency. - Abstract: Thermoelectric generators (TEGs) directly generate electrical power from the geothermal/waste heat as well as contribute to efficient usage of the energy. TEGs cannot be operated at full capacity without additional electronic equipments, since the internal resistances of TEGs are not equal to the device resistances connected across TEGs. For this reason, in this paper, the application of a DC–DC boost converter with maximum power point tracking (MPPT) based on microcontroller embedded in perturb and observe (P&O) algorithm has been proposed to obtain maximum power from a newly designed portable TEG (pTEG) in a real TEG system. The matched condition load for the pTEG has been experimentally investigated. Firstly, the pTEG has been directly charged to the battery pack, secondly it has been charged through the improved convertor with MPPT. In the first one, the pTEG operated with less efficiency than half of its full capacity, whereas, in the second, the pTEG operated efficiency near its full capacity

Cluster management.

Science.gov (United States)

Katz, R

1992-11-01

Cluster management is a management model that fosters decentralization of management, develops leadership potential of staff, and creates ownership of unit-based goals. Unlike shared governance models, there is no formal structure created by committees and it is less threatening for managers. There are two parts to the cluster management model. One is the formation of cluster groups, consisting of all staff and facilitated by a cluster leader. The cluster groups function for communication and problem-solving. The second part of the cluster management model is the creation of task forces. These task forces are designed to work on short-term goals, usually in response to solving one of the unit's goals. Sometimes the task forces are used for quality improvement or system problems. Clusters are groups of not more than five or six staff members, facilitated by a cluster leader. A cluster is made up of individuals who work the same shift. For example, people with job titles who work days would be in a cluster. There would be registered nurses, licensed practical nurses, nursing assistants, and unit clerks in the cluster. The cluster leader is chosen by the manager based on certain criteria and is trained for this specialized role. The concept of cluster management, criteria for choosing leaders, training for leaders, using cluster groups to solve quality improvement issues, and the learning process necessary for manager support are described.

Athletic groin pain (part 2): a prospective cohort study on the biomechanical evaluation of change of direction identifies three clusters of movement patterns

Science.gov (United States)

Franklyn-Miller, A; Richter, C; King, E; Gore, S; Moran, K; Strike, S; Falvey, E C

2017-01-01

Background Athletic groin pain (AGP) is prevalent in sports involving repeated accelerations, decelerations, kicking and change-of-direction movements. Clinical and radiological examinations lack the ability to assess pathomechanics of AGP, but three-dimensional biomechanical movement analysis may be an important innovation. Aim The primary aim was to describe and analyse movements used by patients with AGP during a maximum effort change-of-direction task. The secondary aim was to determine if specific anatomical diagnoses were related to a distinct movement strategy. Methods 322 athletes with a current symptom of chronic AGP participated. Structured and standardised clinical assessments and radiological examinations were performed on all participants. Additionally, each participant performed multiple repetitions of a planned maximum effort change-of-direction task during which whole body kinematics were recorded. Kinematic and kinetic data were examined using continuous waveform analysis techniques in combination with a subgroup design that used gap statistic and hierarchical clustering. Results Three subgroups (clusters) were identified. Kinematic and kinetic measures of the clusters differed strongly in patterns observed in thorax, pelvis, hip, knee and ankle. Cluster 1 (40%) was characterised by increased ankle eversion, external rotation and knee internal rotation and greater knee work. Cluster 2 (15%) was characterised by increased hip flexion, pelvis contralateral drop, thorax tilt and increased hip work. Cluster 3 (45%) was characterised by high ankle dorsiflexion, thorax contralateral drop, ankle work and prolonged ground contact time. No correlation was observed between movement clusters and clinically palpated location of the participant's pain. Conclusions We identified three distinct movement strategies among athletes with long-standing groin pain during a maximum effort change-of-direction task These movement strategies were not related to clinical

Group sequential designs for stepped-wedge cluster randomised trials.

Science.gov (United States)

Grayling, Michael J; Wason, James Ms; Mander, Adrian P

2017-10-01

The stepped-wedge cluster randomised trial design has received substantial attention in recent years. Although various extensions to the original design have been proposed, no guidance is available on the design of stepped-wedge cluster randomised trials with interim analyses. In an individually randomised trial setting, group sequential methods can provide notable efficiency gains and ethical benefits. We address this by discussing how established group sequential methodology can be adapted for stepped-wedge designs. Utilising the error spending approach to group sequential trial design, we detail the assumptions required for the determination of stepped-wedge cluster randomised trials with interim analyses. We consider early stopping for efficacy, futility, or efficacy and futility. We describe first how this can be done for any specified linear mixed model for data analysis. We then focus on one particular commonly utilised model and, using a recently completed stepped-wedge cluster randomised trial, compare the performance of several designs with interim analyses to the classical stepped-wedge design. Finally, the performance of a quantile substitution procedure for dealing with the case of unknown variance is explored. We demonstrate that the incorporation of early stopping in stepped-wedge cluster randomised trial designs could reduce the expected sample size under the null and alternative hypotheses by up to 31% and 22%, respectively, with no cost to the trial's type-I and type-II error rates. The use of restricted error maximum likelihood estimation was found to be more important than quantile substitution for controlling the type-I error rate. The addition of interim analyses into stepped-wedge cluster randomised trials could help guard against time-consuming trials conducted on poor performing treatments and also help expedite the implementation of efficacious treatments. In future, trialists should consider incorporating early stopping of some kind into

Novel Methods to Determine Feeder Locational PV Hosting Capacity and PV Impact Signatures

Energy Technology Data Exchange (ETDEWEB)

Reno, Matthew J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Coogan, Kyle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Seuss, John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Broderick, Robert Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-05-01

Often PV hosting capacity analysis is performed for a limited number of distribution feeders. For medium - voltage distribution feeders, previous results generally analyze less than 20 feeders, and then the results are extrapolated out to similar types of feeders. Previous hosting capacity research has often focused on determining a single value for the hosting capacity for the entire feeder, whereas this research expands previous hosting capacity work to investigate all the regions of the feeder that may allow many different hosting capacity values wit h an idea called locational hosting capacity (LHC)to determine the largest PV size that can be interconnected at different locations (buses) on the study feeders. This report discusses novel methods for analyzing PV interconnections with advanced simulati on methods. The focus is feeder and location - specific impacts of PV that determine the locational PV hosting capacity. Feeder PV impact signature are used to more precisely determine the local maximum hosting capacity of individual areas of the feeder. T he feeder signature provides improved interconnection screening with certain zones that show the risk of impact to the distribution feeder from PV interconnections.

Effect of niobium clustering and precipitation on strength of an NbTi-microalloyed ferritic steel

International Nuclear Information System (INIS)

Kostryzhev, A.G.; Al Shahrani, A.; Zhu, C.; Cairney, J.M.; Ringer, S.P.; Killmore, C.R.; Pereloma, E.V.

2014-01-01

The microstructure–property relationship of an NbTi-microalloyed ferritic steel was studied as a function of thermo-mechanical schedule using a Gleeble 3500 simulator, optical and scanning electron microscope, and atom probe tomography. Contributions to the yield stress from grain size, solid solution, work hardening, particle and cluster strengthening were calculated using the established equations and the measured microstructural parameters. With a decrease in the austenite deformation temperature the yield stress decreased, following a decrease in the number density of >20 nm Nb-rich particles and ≈5 nm Nb-C clusters, although the grain refinement contribution increased. To achieve the maximum cluster/precipitation strengthening in ferrite, the austenite deformation should be carried out in the recrystallisation temperature region where there is a limited tendency for strain-induced precipitation. Based on the analysis of cluster strengthening increment, it could be suggested that the mechanism of dislocation–cluster interaction is closer to shearing than looping

Effect of niobium clustering and precipitation on strength of an NbTi-microalloyed ferritic steel

Energy Technology Data Exchange (ETDEWEB)

Kostryzhev, A.G., E-mail: kostryzhev@yahoo.com [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2500 (Australia); Al Shahrani, A. [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2500 (Australia); Zhu, C.; Cairney, J.M.; Ringer, S.P. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia); School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006 (Australia); Killmore, C.R. [BlueScope Steel Limited, Five Islands Road, Port Kembla, NSW 2505 (Australia); Pereloma, E.V. [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2500 (Australia); UOW Electron Microscopy Centre, University of Wollongong, NSW 2519 (Australia)

2014-06-01

The microstructure–property relationship of an NbTi-microalloyed ferritic steel was studied as a function of thermo-mechanical schedule using a Gleeble 3500 simulator, optical and scanning electron microscope, and atom probe tomography. Contributions to the yield stress from grain size, solid solution, work hardening, particle and cluster strengthening were calculated using the established equations and the measured microstructural parameters. With a decrease in the austenite deformation temperature the yield stress decreased, following a decrease in the number density of >20 nm Nb-rich particles and ≈5 nm Nb-C clusters, although the grain refinement contribution increased. To achieve the maximum cluster/precipitation strengthening in ferrite, the austenite deformation should be carried out in the recrystallisation temperature region where there is a limited tendency for strain-induced precipitation. Based on the analysis of cluster strengthening increment, it could be suggested that the mechanism of dislocation–cluster interaction is closer to shearing than looping.

Outage and Capacity Performance Evaluation of Distributed MIMO Systems over a Composite Fading Channel

Directory of Open Access Journals (Sweden)

Wenjie Peng

2014-01-01

Full Text Available The exact closed-form expressions regarding the outage probability and capacity of distributed MIMO (DMIMO systems over a composite fading channel are derived. This is achieved firstly by using a lognormal approximation to a gamma-lognormal distribution when a mobile station (MS in the cell is in a fixed position, and the so-called maximum ratio transmission/selected combining (MRT-SC and selected transmission/maximum ratio combining (ST-MRC schemes are adopted in uplink and downlink, respectively. Then, based on a newly proposed nonuniform MS cell distribution model, which is more consistent with the MS cell hotspot distribution in an actual communication environment, the average outage probability and capacity formulas are further derived. Finally, the accuracy of the approximation method and the rationality of the corresponding theoretical analysis regarding the system performance are proven and illustrated by computer simulations.

Maruhn-Greiner Maximum of Uranium Fission for Confirmation of Low Energy Nuclear Reactions LENR via a Compound Nucleus with Double Magic Numbers

Science.gov (United States)

Hora, H.; Miley, G. H.

2007-12-01

One of the most convincing facts about LENR due to deuterons of very high concentration in host metals as palladium is the measurement of the large scale minimum of the reaction probability depending on the nucleon number A of generated elements at A = 153 where a local maximum was measured. This is similar to the fission of uranium at A = 119 where the local maximum follows from the Maruhn-Greiner theory if the splitting nuclei are excited to about MeV energy. The LENR generated elements can be documented any time after the reaction by SIMS or K-shell X-ray excitation to show the very unique distribution with the local maximum. An explanation is based on the strong Debye screening of the Maxwellian deuterons within the degenerate rigid electron background especially within the swimming electron layer at the metal surface or at interfaces. The deuterons behave like neutrals at distances of about 2 picometers. They may form clusters due to soft attraction in the range above thermal energy. Clusters of 10 pm diameter may react over long time probabilities (megaseconds) with Pd nuclei leading to a double magic number compound nucleus which splits like in fission to the A = 153 element distribution.

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.

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

Electrochemical performances and capacity fading behaviors of activated carbon/hard carbon lithium ion capacitor

International Nuclear Information System (INIS)

Sun, Xianzhong; Zhang, Xiong; Liu, Wenjie; Wang, Kai; Li, Chen; Li, Zhao; Ma, Yanwei

2017-01-01

Highlights: • Three-electrode pouch cell is used to investigate the capacity fading of AC/HC LIC. • the electrode potential swing is critical for the cycleability of a LIC cell. • Different capacity fading behaviors are discussed. • A large-capacity LIC pouch cell has been assembled with a specific energy of 18.1 Wh kg −1 based on the total weight. - Abstract: Lithium ion capacitor (LIC) is one of the most promising electrochemical energy storage devices, which offers rapid charging-discharging capability and long cycle life. We have fabricated LIC pouch cells using an electrochemically-driven lithium pre-doping method through a three-electrode pouch cell structure. The active materials of cathode and anode of LIC cell are activated carbon and pre-lithiated hard carbon, respectively. The electrochemical performances and the capacity fading behaviors of LICs in the voltage range of 2.0 − 4.0 V have been studied. The specific energy and specific power reach 73.6 Wh kg −1 and 11.9 kW kg −1 based on the weight of the active materials in both cathode and anode, respectively. Since the cycling performance is actually determined by hard carbon anode, the anode potential swings are emphasized. The capacity fading of LIC upon cycling is proposed to be caused by the increases of internal resistance and the consumption of lithium stored in anode. Finally, a large-capacity LIC pouch cell has been assembled with a maximum specific energy of 18.1 Wh kg −1 and a maximum specific power of 3.7 kW kg −1 based on the weight of the whole cell.

Consumer Perception of Retail Pork Bacon Attributes Using Adaptive Choice-based Conjoint Analysis and Maximum Differential Scaling.

Science.gov (United States)

McLean, K G; Hanson, D J; Jervis, S M; Drake, M A

2017-11-01

Bacon is one of the most recognizable consumer pork products and is differentiated by appearance, flavor, thickness, and several possible product claims. The objective of this study was to explore the attributes of retail bacon that influence consumers to purchase and consume bacon. An Adaptive Choice-Based Conjoint (ACBC) survey was designed for attributes of raw American-style bacon. An ACBC survey (N = 1410 consumers) and Kano questioning were applied to determine the key attributes that influenced consumer purchase. Attributes included package size, brand, thickness, label claims, flavor, price, and images of the bacon package displaying fat:lean ratio. Maximum Difference Scaling (MaxDiff) was used to rank appeal of 20 different bacon images with variable fat:lean ration and slice shape. The most important attribute for bacon purchase was price followed by fat:lean appearance and then flavor. Three consumer clusters were identified with distinct preferences. For 2 clusters, price was not the primary attribute. Understanding preferences of distinct consumer clusters will enable manufacturers to target consumers and make more appealing bacon. Adaptive Choice-Based Conjoint (ACBC) is a research technique that allows consumers to react to assembled products and identify product attributes that they prefer. Kano questions allow researchers to look at the individual aspects of a product and understand consumer sentiment and expectations towards those product qualities while Maximum Difference scaling allows consumers to directly rank single attributes of a product relative to one another. A combination of these 3 approaches can provide key understandings on consumer perception of retail bacon allowing companies to optimize and maximize their development and advertising resources. © 2017 Institute of Food Technologists®.

Common Factor Analysis Versus Principal Component Analysis: Choice for Symptom Cluster Research

Directory of Open Access Journals (Sweden)

Hee-Ju Kim, PhD, RN

2008-03-01

Conclusion: If the study purpose is to explain correlations among variables and to examine the structure of the data (this is usual for most cases in symptom cluster research, CFA provides a more accurate result. If the purpose of a study is to summarize data with a smaller number of variables, PCA is the choice. PCA can also be used as an initial step in CFA because it provides information regarding the maximum number and nature of factors. In using factor analysis for symptom cluster research, several issues need to be considered, including subjectivity of solution, sample size, symptom selection, and level of measure.

Confined SnO2 quantum-dot clusters in graphene sheets as high-performance anodes for lithium-ion batteries

Science.gov (United States)

Zhu, Chengling; Zhu, Shenmin; Zhang, Kai; Hui, Zeyu; Pan, Hui; Chen, Zhixin; Li, Yao; Zhang, Di; Wang, Da-Wei

2016-01-01

Construction of metal oxide nanoparticles as anodes is of special interest for next-generation lithium-ion batteries. The main challenge lies in their rapid capacity fading caused by the structural degradation and instability of solid-electrolyte interphase (SEI) layer during charge/discharge process. Herein, we address these problems by constructing a novel-structured SnO2-based anode. The novel structure consists of mesoporous clusters of SnO2 quantum dots (SnO2 QDs), which are wrapped with reduced graphene oxide (RGO) sheets. The mesopores inside the clusters provide enough room for the expansion and contraction of SnO2 QDs during charge/discharge process while the integral structure of the clusters can be maintained. The wrapping RGO sheets act as electrolyte barrier and conductive reinforcement. When used as an anode, the resultant composite (MQDC-SnO2/RGO) shows an extremely high reversible capacity of 924 mAh g−1 after 200 cycles at 100 mA g−1, superior capacity retention (96%), and outstanding rate performance (505 mAh g−1 after 1000 cycles at 1000 mA g−1). Importantly, the materials can be easily scaled up under mild conditions. Our findings pave a new way for the development of metal oxide towards enhanced lithium storage performance. PMID:27181691

Carrying Capacity Model Applied to Coastal Ecotourism of Baluran National Park, Indonesia

Science.gov (United States)

Armono, H. D.; Rosyid, D. M.; Nuzula, N. I.

2017-07-01

The resources of Baluran National Park have been used for marine and coastal ecotourism. The increasing number of visitors has led to the increasing of tourists and its related activities. This condition will cause the degradation of resources and the welfare of local communities. This research aims to determine the sustainability of coastal ecotourism management by calculating the effective number of tourists who can be accepted. The study uses the concept of tourism carrying capacity, consists the ecological environment, economic, social and physical carrying capacity. The results of the combined carrying capacity analysis in Baluran National Park ecotourism shows that the number of 3.288 people per day (151.248 tourists per year) is the maximum number of accepted tourists. The current number of tourist arrivals is only 241 people per day (87.990 tourists per year) which is far below the carrying capacity.

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

AIDSCAP initiative. Innovation in NGO capacity building: Tanzania AIDS project.

Science.gov (United States)

Dadian, M J

1998-01-01

Tanzania has since the mid-1980s experienced some of the highest rates of HIV infection in the world, with data now showing the mean levels of HIV seroprevalence nationwide to be greater than 13%, and even higher than 30% in some districts. By 2000, as many as 2.4 million Tanzanians will be infected with HIV and more than 850,000 Tanzanian children will be orphaned by the epidemic. The Tanzania AIDS Project (TAP), funded by the US Agency for International Development (USAID), was implemented through the AIDS Control and Prevention (AIDSCAP) Project by Family Health International (FHI) during 1993-97. TAP will receive support throughout 1998 through a cooperative agreement between USAID and FHI. Nongovernmental organization (NGO) representatives meet on a regular basis in Dar es Salaam and in 8 other regions of the country to plan and coordinate the major aspects of TAP's HIV/AIDS prevention activities in each area. The author describes the evolution of the idea to bring NGOs together into geographic clusters, the diversity of talents enjoyed from using the cluster concept, building institutional capacity, the challenges facing TAP's 9 clusters, and working with traditional communities.

Secrecy Capacity of a Class of Orthogonal Relay Eavesdropper Channels

Directory of Open Access Journals (Sweden)

Aggarwal Vaneet

2009-01-01

Full Text Available The secrecy capacity of relay channels with orthogonal components is studied in the presence of an additional passive eavesdropper node. The relay and destination receive signals from the source on two orthogonal channels such that the destination also receives transmissions from the relay on its channel. The eavesdropper can overhear either one or both of the orthogonal channels. Inner and outer bounds on the secrecy capacity are developed for both the discrete memoryless and the Gaussian channel models. For the discrete memoryless case, the secrecy capacity is shown to be achieved by a partial decode-and-forward (PDF scheme when the eavesdropper can overhear only one of the two orthogonal channels. Two new outer bounds are presented for the Gaussian model using recent capacity results for a Gaussian multiantenna point-to-point channel with a multiantenna eavesdropper. The outer bounds are shown to be tight for two subclasses of channels. The first subclass is one in which the source and relay are clustered, and the eavesdropper receives signals only on the channel from the source and the relay to the destination, for which the PDF strategy is optimal. The second is a subclass in which the source does not transmit to the relay, for which a noise-forwarding strategy is optimal.

System Capacity Limits Introduced by Data Fusion on Cooperative Spectrum Sensing under Correlated Environments

DEFF Research Database (Denmark)

Pratas, Nuno; Marchetti, Nicola; Prasad, Neeli R.

2010-01-01

on cooperative sensing schemes. The analysis is supported by evaluation metrics which accounts for the perceived capacity limits. The analysis is performed along the data fusion chain, comparing several scenarios encompassing different degrees of environment correlation between the cluster nodes, number......Spectrum sensing, the cornerstone of the Cognitive Radio paradigm, has been the focus of intensive research, from which the main conclusion was that its performance can be greatly enhanced through the use of cooperative sensing schemes. Nevertheless, if a proper design of the cooperative scheme...... is not followed, then the use of cooperative schemes will introduce some limitations in the network perceived capacity. In this paper, we analyze the performance of a cooperative spectrum sensing scheme based on Data Fusion, by measuring the perceived capacity limits introduced by the use of Data Fusion...

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.

Evaluation of hierarchical agglomerative cluster analysis methods for discrimination of primary biological aerosol

Directory of Open Access Journals (Sweden)

I. Crawford

2015-11-01

Full Text Available In this paper we present improved methods for discriminating and quantifying primary biological aerosol particles (PBAPs by applying hierarchical agglomerative cluster analysis to multi-parameter ultraviolet-light-induced fluorescence (UV-LIF spectrometer data. The methods employed in this study can be applied to data sets in excess of 1 × 106 points on a desktop computer, allowing for each fluorescent particle in a data set to be explicitly clustered. This reduces the potential for misattribution found in subsampling and comparative attribution methods used in previous approaches, improving our capacity to discriminate and quantify PBAP meta-classes. We evaluate the performance of several hierarchical agglomerative cluster analysis linkages and data normalisation methods using laboratory samples of known particle types and an ambient data set. Fluorescent and non-fluorescent polystyrene latex spheres were sampled with a Wideband Integrated Bioaerosol Spectrometer (WIBS-4 where the optical size, asymmetry factor and fluorescent measurements were used as inputs to the analysis package. It was found that the Ward linkage with z-score or range normalisation performed best, correctly attributing 98 and 98.1 % of the data points respectively. The best-performing methods were applied to the BEACHON-RoMBAS (Bio–hydro–atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen–Rocky Mountain Biogenic Aerosol Study ambient data set, where it was found that the z-score and range normalisation methods yield similar results, with each method producing clusters representative of fungal spores and bacterial aerosol, consistent with previous results. The z-score result was compared to clusters generated with previous approaches (WIBS AnalysiS Program, WASP where we observe that the subsampling and comparative attribution method employed by WASP results in the overestimation of the fungal spore concentration by a factor of 1.5 and the

Relationship Quality and Innovation Capacity of Chains: The Case of the Traditional Food Sector in the EU

Directory of Open Access Journals (Sweden)

Xavier Gellynck

2011-10-01

Full Text Available The purpose of the paper is to explore how the perceived relationship quality is related to the innovation capacity in chains of the traditional food sector. Based on suggestions from theory and previous studies, empirical evidence is drawn from a survey of 90 traditional food chains including 270 chain partners from three European countries in four traditional food product categories. Heterogeneity across these chains is first examined based on cluster analysis that identifies three distinct clusters interpreted as reflecting three levels of intensity in innovation capacity: high, medium, and low. Next, we define measures of the chain relationship quality through characteristics such as trust, conflict and reputation. Results suggest that various aspects of chain relationship quality and relationship directions are differently important for the innovation capacity levels in traditional food chains. In particular the perception of the relationship quality between the food manufacturer and its supplier (and vice versa is explored to be important. The better this relationship is perceived by one chain partner, the higher is the innovation capacity of the whole chain. Thus, our results strengthen the emerging conclusion that firms benefit from participating in networks but depend on its partner’s choices and perceptions. In future research, it should be explored how different national and cultural environments facilitate or hamper the innovation capacity in traditional food chains. It is also suggested to extend the complexity of the investigated system and to apply our novel approach to other food sectors, than the traditional food sector, in order to improve its generalizability.

Maruhn-Greiner Maximum for Confirmation of Low Energy Nuclear Reactions (LENR) via a Compound Nucleus with Double Magic Numbers

Science.gov (United States)

Hora, Heinrich; Miley, George

2007-03-01

One of the most convincing facts about LENR due to deuterons (ds) or protons of very high concentration in host metals of palladium is the measurement of the large scale minimum in the reaction probability with product elements centered around the nucleon number A = 153. The local maximum was measured in this region is similar to fission of uranium at A = 119 where the local maximum follows the Maruhn-Greiner mechanism^1. We suggest this phenomenon can be explained by the strong screening of the Maxwellian ds on the degenerate rigid electron background within the swimming electrons at the metal surface or thin filem interfaces. The deuterons behave like neutrals at distances of above 2 picometers (pm) and form clusters due to soft attraction in the range of thermal energy; 10 pm diameter clusters can react over long time scales (10^6 s) with Pd leading to double magic number compound nuclei 306x126 decaying via fission to an A=153 element distribution. J. Maruhn et al, Phys. Rev. Letters 32, 548 (1974) H. Hora, G.H. Miley, CzechJ. Phys. 48, 1111 (1998)

Room at the Mountain: Estimated Maximum Amounts of Commercial Spent Nuclear Fuel Capable of Disposal in a Yucca Mountain Repository

International Nuclear Information System (INIS)

Kessler, John H.; Kemeny, John; King, Fraser; Ross, Alan M.; Ross, Benjamen

2006-01-01

The purpose of this paper is to present an initial analysis of the maximum amount of commercial spent nuclear fuel (CSNF) that could be emplaced into a geological repository at Yucca Mountain. This analysis identifies and uses programmatic, material, and geological constraints and factors that affect this estimation of maximum amount of CSNF for disposal. The conclusion of this initial analysis is that the current legislative limit on Yucca Mountain disposal capacity, 63,000 MTHM of CSNF, is a small fraction of the available physical capacity of the Yucca Mountain system assuming the current high-temperature operating mode (HTOM) design. EPRI is confident that at least four times the legislative limit for CSNF (∼260,000 MTHM) can be emplaced in the Yucca Mountain system. It is possible that with additional site characterization, upwards of nine times the legislative limit (∼570,000 MTHM) could be emplaced. (authors)

Ultrathin mesoporous Co_3O_4 nanosheets-constructed hierarchical clusters as high rate capability and long life anode materials for lithium-ion batteries

International Nuclear Information System (INIS)

Wu, Shengming; Xia, Tian; Wang, Jingping; Lu, Feifei; Xu, Chunbo; Zhang, Xianfa; Huo, Lihua; Zhao, Hui

2017-01-01

Graphical abstract: Ultrathin mesoporous Co_3O_4 nanosheets-constructed hierarchical clusters (UMCN-HCs) have been successfully synthesized via a facile hydrothermal method followed by a subsequent thermolysis treatment. When tested as anode materials for LIBs, UMCN-HCs achieve high reversible capacity, good long cycling life, and rate capability. - Highlights: • UMCN-HCs show high capacity, excellent stability, and good rate capability. • UMCN-HCs retain a capacity of 1067 mAh g"−"1 after 100 cycles at 100 mA g"−"1. • UMCN-HCs deliver a capacity of 507 mAh g"−"1 after 500 cycles at 2 A g"−"1. - Abstract: Herein, Ultrathin mesoporous Co_3O_4 nanosheets-constructed hierarchical clusters (UMCN-HCs) have been successfully synthesized via a facile hydrothermal method followed by a subsequent thermolysis treatment at 600 °C in air. The products consist of cluster-like Co_3O_4 microarchitectures, which are assembled by numerous ultrathin mesoporous Co_3O_4 nanosheets. When tested as anode materials for lithium-ion batteries, UMCN-HCs deliver a high reversible capacity of 1067 mAh g"−"1 at a current density of 100 mA g"−"1 after 100 cycles. Even at 2 A g"−"1, a stable capacity as high as 507 mAh g"−"1 can be achieved after 500 cycles. The high reversible capacity, excellent cycling stability, and good rate capability of UMCN-HCs may be attributed to their mesoporous sheet-like nanostructure. The sheet-layered structure of UMCN-HCs may buffer the volume change during the lithiation-delithiation process, and the mesoporous characteristic make lithium-ion transfer more easily at the interface between the active electrode and the electrolyte.

Benefits of pulmonary rehabilitation in patients with COPD and normal exercise capacity.

Science.gov (United States)

Lan, Chou-Chin; Chu, Wen-Hua; Yang, Mei-Chen; Lee, Chih-Hsin; Wu, Yao-Kuang; Wu, Chin-Pyng

2013-09-01

Pulmonary rehabilitation (PR) is beneficial for patients with COPD, with improvement in exercise capacity and health-related quality of life. Despite these overall benefits, the responses to PR vary significantly among different individuals. It is not clear if PR is beneficial for patients with COPD and normal exercise capacity. We aimed to investigate the effects of PR in patients with normal exercise capacity on health-related quality of life and exercise capacity. Twenty-six subjects with COPD and normal exercise capacity were studied. All subjects participated in 12-week, 2 sessions per week, hospital-based, out-patient PR. Baseline and post-PR status were evaluated by spirometry, the St George's Respiratory Questionnaire, cardiopulmonary exercise test, respiratory muscle strength, and dyspnea scores. The mean FEV1 in the subjects was 1.29 ± 0.47 L/min, 64.8 ± 23.0% of predicted. After PR there was significant improvement in maximal oxygen uptake and work rate. Improvements in St George's Respiratory Questionnaire scores of total, symptoms, activity, and impact were accompanied by improvements of exercise capacity, respiratory muscle strength, maximum oxygen pulse, and exertional dyspnea scores (all P exercise after PR. Exercise training can result in significant improvement in health-related quality of life, exercise capacity, respiratory muscle strength, and exertional dyspnea in subjects with COPD and normal exercise capacity. Exercise training is still indicated for patients with normal exercise capacity.

The Atacama Cosmology Telescope (ACT): Beam Profiles and First SZ Cluster Maps

Science.gov (United States)

Hincks, A. D.; Acquaviva, V.; Ade, P. A.; Aguirre, P.; Amiri, M.; Appel, J. W.; Barrientos, L. F.; Battistelli, E. S.; Bond, J. R.; Brown, B.;

LTE-A cellular networks multi-hop relay for coverage, capacity and performance enhancement

CERN Document Server

Yahya, Abid

2017-01-01

In this book, three different methods are presented to enhance the capacity and coverage area in LTE-A cellular networks. The scope involves the evaluation of the effect of the RN location in terms of capacity and the determination of the optimum location of the relay that provides maximum achievable data rate for users with limited interference at the cell boundaries. This book presents a new model to enhance both capacity and coverage area in LTE-A cellular network by determining the optimum location for the RN with limited interference. The new model is designed to enhance the capacity of the relay link by employing two antennas in RN. This design enables the relay link to absorb more users at cell edge regions. An algorithm called the Balance Power Algorithm (BPA) is developed to reduce MR power consumption. The book pertains to postgraduate students and researchers in wireless & mobile communications. Provides a variety of methods for enhancing capacity and coverage in LTE-A cellular networks Develop...

Unit commitment solution using agglomerative and divisive cluster algorithm : an effective new methodology

Energy Technology Data Exchange (ETDEWEB)

Reddy, N.M.; Reddy, K.R. [G. Narayanamma Inst. of Technology and Science, Hyderabad (India). Dept. of Electrical Engineering; Ramana, N.V. [JNTU College of Engineering, Jagityala (India). Dept. of Electrical Engineering

2008-07-01

Thermal power plants consist of several generating units with different generating capacities, fuel cost per MWH generated, minimum up/down times, and start-up or shut-down costs. The Unit Commitment (UC) problem in power systems involves determining the start-up and shut-down schedules of thermal generating units to meet forecasted load over a future short term for a period of one to seven days. This paper presented a new approach for the most complex UC problem using agglomerative and divisive hierarchical clustering. Euclidean costs, which are a measure of differences in fuel cost and start-up costs of any two units, were first calculated. Then, depending on the value of Euclidean costs, similar type of units were placed in a cluster. The proposed methodology has 2 individual algorithms. An agglomerative cluster algorithm is used while the load is increasing, and a divisive cluster algorithm is used when the load is decreasing. A search was conducted for an optimal solution for a minimal number of clusters and cluster data points. A standard ten-unit thermal unit power system was used to test and evaluate the performance of the method for a period of 24 hours. The new approach proved to be quite effective and satisfactory. 15 refs., 9 tabs., 5 figs.

DETECTION OF SOLAR-LIKE OSCILLATIONS FROM KEPLER PHOTOMETRY OF THE OPEN CLUSTER NGC 6819

International Nuclear Information System (INIS)

Stello, Dennis; Bedding, Timothy R.; Huber, Daniel; Basu, Sarbani; Bruntt, Hans; Mosser, BenoIt; Barban, Caroline; Goupil, Marie-Jo; Stevens, Ian R.; Chaplin, William J.; Elsworth, Yvonne P.; Hekker, Saskia; Brown, Timothy M.; Christensen-Dalsgaard, Joergen; Kjeldsen, Hans; Arentoft, Torben; Gilliland, Ronald L.; Ballot, Jerome; GarcIa, Rafael A.; Mathur, Savita

2010-01-01

Asteroseismology of stars in clusters has been a long-sought goal because the assumption of a common age, distance, and initial chemical composition allows strong tests of the theory of stellar evolution. We report results from the first 34 days of science data from the Kepler Mission for the open cluster NGC 6819-one of the four clusters in the field of view. We obtain the first clear detections of solar-like oscillations in the cluster red giants and are able to measure the large frequency separation, Δν, and the frequency of maximum oscillation power, ν max . We find that the asteroseismic parameters allow us to test cluster membership of the stars, and even with the limited seismic data in hand, we can already identify four possible non-members despite their having a better than 80% membership probability from radial velocity measurements. We are also able to determine the oscillation amplitudes for stars that span about 2 orders of magnitude in luminosity and find good agreement with the prediction that oscillation amplitudes scale as the luminosity to the power of 0.7. These early results demonstrate the unique potential of asteroseismology of the stellar clusters observed by Kepler.

Are clusters of dietary patterns and cluster membership stable over time? Results of a longitudinal cluster analysis study.

Science.gov (United States)

Walthouwer, Michel Jean Louis; Oenema, Anke; Soetens, Katja; Lechner, Lilian; de Vries, Hein

2014-11-01

Developing nutrition education interventions based on clusters of dietary patterns can only be done adequately when it is clear if distinctive clusters of dietary patterns can be derived and reproduced over time, if cluster membership is stable, and if it is predictable which type of people belong to a certain cluster. Hence, this study aimed to: (1) identify clusters of dietary patterns among Dutch adults, (2) test the reproducibility of these clusters and stability of cluster membership over time, and (3) identify sociodemographic predictors of cluster membership and cluster transition. This study had a longitudinal design with online measurements at baseline (N=483) and 6 months follow-up (N=379). Dietary intake was assessed with a validated food frequency questionnaire. A hierarchical cluster analysis was performed, followed by a K-means cluster analysis. Multinomial logistic regression analyses were conducted to identify the sociodemographic predictors of cluster membership and cluster transition. At baseline and follow-up, a comparable three-cluster solution was derived, distinguishing a healthy, moderately healthy, and unhealthy dietary pattern. Male and lower educated participants were significantly more likely to have a less healthy dietary pattern. Further, 251 (66.2%) participants remained in the same cluster, 45 (11.9%) participants changed to an unhealthier cluster, and 83 (21.9%) participants shifted to a healthier cluster. Men and people living alone were significantly more likely to shift toward a less healthy dietary pattern. Distinctive clusters of dietary patterns can be derived. Yet, cluster membership is unstable and only few sociodemographic factors were associated with cluster membership and cluster transition. These findings imply that clusters based on dietary intake may not be suitable as a basis for nutrition education interventions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of a cluster-jet target for PANDA

International Nuclear Information System (INIS)

Gruber, A.; Marton, J.; Widmann, E.; Zmeskal, J.; PANDA Cluster Jet Target Group

2006-01-01

Full text: The Stefan Meyer Institute (SMI) is part of the international PANDA collaboration. The universal detector will be constructed for the future high-energy antiproton storage ring HESR at FAIR (Facility for Antiproton and Ion Research, GSI/Darmstadt). PANDA will use antiproton beams (1.5 to 15 GeV/c) for hadron physics in the charmonium region. The physics program of PANDA will comprehend charmonium spectroscopy below and above open charm threshold, search for exotics (glueballs, hybrids), lambda and double-lambda hypernuclei studies and the investigation of in-medium modifications of charmed mesons - an experimentally unexplored field. SMI contributes to major parts of the PANDA detector like the hydrogen cluster-jet target and the antiproton - cluster jet interaction zone: in order to reach the desired target density, an optimization of the nozzle and the skimmer arrangement is essential. A density-profile monitor for the cluster-jet was designed and built at SMI. Several nozzle types have been studied using different gases, temperatures and inlet pressures. To ensure low background the residual gas load in the interaction zone has to be minimized. The installation of NEG (non-evaporative-getter) coated beam pipes is planned. A prototype of the interaction zone has been set up at SMI. The pumping capacity of NEG and the reactivation cycles were tested. The status of the development of the cluster-jet target and studies of the interaction region will be presented (author)

Functional Capacity in Adults With Cerebral Palsy: Lower Limb Muscle Strength Matters.

Science.gov (United States)

Gillett, Jarred G; Lichtwark, Glen A; Boyd, Roslyn N; Barber, Lee A

2018-05-01

To investigate the relation between lower limb muscle strength, passive muscle properties, and functional capacity outcomes in adults with cerebral palsy (CP). Cross-sectional study. Tertiary institution biomechanics laboratory. Adults with spastic-type CP (N=33; mean age, 25y; range, 15-51y; mean body mass, 70.15±21.35kg) who were either Gross Motor Function Classification System (GMFCS) level I (n=20) or level II (n=13). Not applicable. Six-minute walk test (6MWT) distance (m), lateral step-up (LSU) test performance (total repetitions), timed up-stairs (TUS) performance (s), maximum voluntary isometric strength of plantar flexors (PF) and dorsiflexors (DF) (Nm.kg -1 ), and passive ankle joint and muscle stiffness. Maximum isometric PF strength independently explained 61% of variance in 6MWT performance, 57% of variance in LSU test performance, and 50% of variance in TUS test performance. GMFCS level was significantly and independently related to all 3 functional capacity outcomes, and age was retained as a significant independent predictor of LSU and TUS test performance. Passive medial gastrocnemius muscle fascicle stiffness and ankle joint stiffness were not significantly related to functional capacity measures in any of the multiple regression models. Low isometric PF strength was the most important independent variable related to distance walked on the 6MWT, fewer repetitions on the LSU test, and slower TUS test performance. These findings suggest lower isometric muscle strength contributes to the decline in functional capacity in adults with CP. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Clusters and how to make it work : Cluster Strategy Toolkit

NARCIS (Netherlands)

Manickam, Anu; van Berkel, Karel

2014-01-01

Clusters are the magic answer to regional economic development. Firms in clusters are more innovative; cluster policy dominates EU policy; ‘top-sectors’ and excellence are the choice of national policy makers; clusters are ‘in’. But, clusters are complex, clusters are ‘messy’; there is no clear

Cluster dynamics at different cluster size and incident laser wavelengths

International Nuclear Information System (INIS)

Desai, Tara; Bernardinello, Andrea

2002-01-01

X-ray emission spectra from aluminum clusters of diameter -0.4 μm and gold clusters of dia. ∼1.25 μm are experimentally studied by irradiating the cluster foil targets with 1.06 μm laser, 10 ns (FWHM) at an intensity ∼10 12 W/cm 2 . Aluminum clusters show a different spectra compared to bulk material whereas gold cluster evolve towards bulk gold. Experimental data are analyzed on the basis of cluster dimension, laser wavelength and pulse duration. PIC simulations are performed to study the behavior of clusters at higher intensity I≥10 17 W/cm 2 for different size of the clusters irradiated at different laser wavelengths. Results indicate the dependence of cluster dynamics on cluster size and incident laser wavelength

Influence of pine bark particle size and pH on cation exchange capacity

Science.gov (United States)

Cation exchange capacity (CEC) describes the maximum quantity of cations a soil or substrate can hold while being exchangeable with the soil solution. While CEC has been studied for peat-based substrates, relatively little work has documented factors that affect CEC of pine bark substrates. The ob...

Analysis of factors that influence the maximum number of repetitions in two upper-body resistance exercises: curl biceps and bench press.

Science.gov (United States)

Iglesias, Eliseo; Boullosa, Daniel A; Dopico, Xurxo; Carballeira, Eduardo

2010-06-01

The purpose of this study was to analyze the influence of exercise type, set configuration, and relative intensity load on relationship between 1 repetition maximum (1RM) and maximum number of repetitions (MNR). Thirteen male subjects, experienced in resistance training, were tested in bench press and biceps curl for 1RM, MNR at 90% of 1RM with cluster set configuration (rest of 30s between repetitions) and MNR at 70% of 1RM with traditional set configuration (no rest between repetitions). A lineal encoder was used for measuring displacement of load. Analysis of variance analysis revealed a significant effect of load (pbench press and biceps curl, respectively; pbench press and biceps curl, respectively; p>0.05). Correlation between 1RM and MNR was significant for medium-intensity in biceps curl (r=-0.574; pvelocity along set, so velocity seems to be similar at a same relative intensity for subjects with differences in maximum strength levels. From our results, we suggest the employment of MNR rather than % of 1RM for training monitoring. Furthermore, we suggest the introduction of cluster set configuration for upper-body assessment of MNR and for upper-body muscular endurance training at high-intensity loads, as it seems an efficient approach in looking for sessions with greater training volumes. This could be an interesting approach for such sports as wrestling or weightlifting.

Text Clustering Algorithm Based on Random Cluster Core

Directory of Open Access Journals (Sweden)

Huang Long-Jun

2016-01-01

Full Text Available Nowadays clustering has become a popular text mining algorithm, but the huge data can put forward higher requirements for the accuracy and performance of text mining. In view of the performance bottleneck of traditional text clustering algorithm, this paper proposes a text clustering algorithm with random features. This is a kind of clustering algorithm based on text density, at the same time using the neighboring heuristic rules, the concept of random cluster is introduced, which effectively reduces the complexity of the distance calculation.

A Dimensionality Reduction-Based Multi-Step Clustering Method for Robust Vessel Trajectory Analysis

Directory of Open Access Journals (Sweden)

Huanhuan Li

2017-08-01

Full Text Available The Shipboard Automatic Identification System (AIS is crucial for navigation safety and maritime surveillance, data mining and pattern analysis of AIS information have attracted considerable attention in terms of both basic research and practical applications. Clustering of spatio-temporal AIS trajectories can be used to identify abnormal patterns and mine customary route data for transportation safety. Thus, the capacities of navigation safety and maritime traffic monitoring could be enhanced correspondingly. However, trajectory clustering is often sensitive to undesirable outliers and is essentially more complex compared with traditional point clustering. To overcome this limitation, a multi-step trajectory clustering method is proposed in this paper for robust AIS trajectory clustering. In particular, the Dynamic Time Warping (DTW, a similarity measurement method, is introduced in the first step to measure the distances between different trajectories. The calculated distances, inversely proportional to the similarities, constitute a distance matrix in the second step. Furthermore, as a widely-used dimensional reduction method, Principal Component Analysis (PCA is exploited to decompose the obtained distance matrix. In particular, the top k principal components with above 95% accumulative contribution rate are extracted by PCA, and the number of the centers k is chosen. The k centers are found by the improved center automatically selection algorithm. In the last step, the improved center clustering algorithm with k clusters is implemented on the distance matrix to achieve the final AIS trajectory clustering results. In order to improve the accuracy of the proposed multi-step clustering algorithm, an automatic algorithm for choosing the k clusters is developed according to the similarity distance. Numerous experiments on realistic AIS trajectory datasets in the bridge area waterway and Mississippi River have been implemented to compare our

A Dimensionality Reduction-Based Multi-Step Clustering Method for Robust Vessel Trajectory Analysis.

Science.gov (United States)

Li, Huanhuan; Liu, Jingxian; Liu, Ryan Wen; Xiong, Naixue; Wu, Kefeng; Kim, Tai-Hoon

2017-08-04

The Shipboard Automatic Identification System (AIS) is crucial for navigation safety and maritime surveillance, data mining and pattern analysis of AIS information have attracted considerable attention in terms of both basic research and practical applications. Clustering of spatio-temporal AIS trajectories can be used to identify abnormal patterns and mine customary route data for transportation safety. Thus, the capacities of navigation safety and maritime traffic monitoring could be enhanced correspondingly. However, trajectory clustering is often sensitive to undesirable outliers and is essentially more complex compared with traditional point clustering. To overcome this limitation, a multi-step trajectory clustering method is proposed in this paper for robust AIS trajectory clustering. In particular, the Dynamic Time Warping (DTW), a similarity measurement method, is introduced in the first step to measure the distances between different trajectories. The calculated distances, inversely proportional to the similarities, constitute a distance matrix in the second step. Furthermore, as a widely-used dimensional reduction method, Principal Component Analysis (PCA) is exploited to decompose the obtained distance matrix. In particular, the top k principal components with above 95% accumulative contribution rate are extracted by PCA, and the number of the centers k is chosen. The k centers are found by the improved center automatically selection algorithm. In the last step, the improved center clustering algorithm with k clusters is implemented on the distance matrix to achieve the final AIS trajectory clustering results. In order to improve the accuracy of the proposed multi-step clustering algorithm, an automatic algorithm for choosing the k clusters is developed according to the similarity distance. Numerous experiments on realistic AIS trajectory datasets in the bridge area waterway and Mississippi River have been implemented to compare our proposed method with

Evidence for nano-Si clusters in amorphous SiO anode materials for rechargeable Li-ion batteries

International Nuclear Information System (INIS)

Sepehri-Amin, H.; Ohkubo, T.; Kodzuka, M.; Yamamura, H.; Saito, T.; Iba, H.; Hono, K.

2013-01-01

Atom probe tomography and high resolution transmission electron microscopy have shown the presence of nano-sized amorphous Si clusters in non-disproportionated amorphous SiO powders are under consideration for anode materials in Li-ion batteries. After Li insertion/extraction, no change was found in the chemistry and structure of the Si clusters. However, Li atoms were found to be trapped at the amorphous SiO phase after Li insertion/extraction, which may be attributed to the large capacity fade after the first charge/discharge cycle

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

Workload Characterization of a Leadership Class Storage Cluster

Energy Technology Data Exchange (ETDEWEB)

Kim, Youngjae [ORNL; Gunasekaran, Raghul [ORNL; Shipman, Galen M [ORNL; Dillow, David A [ORNL; Zhang, Zhe [ORNL; Settlemyer, Bradley W [ORNL

2010-01-01

Understanding workload characteristics is critical for optimizing and improving the performance of current systems and software, and architecting new storage systems based on observed workload patterns. In this paper, we characterize the scientific workloads of the world s fastest HPC (High Performance Computing) storage cluster, Spider, at the Oak Ridge Leadership Computing Facility (OLCF). Spider provides an aggregate bandwidth of over 240 GB/s with over 10 petabytes of RAID 6 formatted capacity. OLCFs flagship petascale simulation platform, Jaguar, and other large HPC clusters, in total over 250 thousands compute cores, depend on Spider for their I/O needs. We characterize the system utilization, the demands of reads and writes, idle time, and the distribution of read requests to write requests for the storage system observed over a period of 6 months. From this study we develop synthesized workloads and we show that the read and write I/O bandwidth usage as well as the inter-arrival time of requests can be modeled as a Pareto distribution.

Non-negative matrix factorization by maximizing correntropy for cancer clustering

KAUST Repository

Wang, Jim Jing-Yan; Wang, Xiaolei; Gao, Xin

2013-01-01

Background: Non-negative matrix factorization (NMF) has been shown to be a powerful tool for clustering gene expression data, which are widely used to classify cancers. NMF aims to find two non-negative matrices whose product closely approximates the original matrix. Traditional NMF methods minimize either the l2 norm or the Kullback-Leibler distance between the product of the two matrices and the original matrix. Correntropy was recently shown to be an effective similarity measurement due to its stability to outliers or noise.Results: We propose a maximum correntropy criterion (MCC)-based NMF method (NMF-MCC) for gene expression data-based cancer clustering. Instead of minimizing the l2 norm or the Kullback-Leibler distance, NMF-MCC maximizes the correntropy between the product of the two matrices and the original matrix. The optimization problem can be solved by an expectation conditional maximization algorithm.Conclusions: Extensive experiments on six cancer benchmark sets demonstrate that the proposed method is significantly more accurate than the state-of-the-art methods in cancer clustering. 2013 Wang et al.; licensee BioMed Central Ltd.

Non-negative matrix factorization by maximizing correntropy for cancer clustering

KAUST Repository

Wang, Jim Jing-Yan

2013-03-24

Background: Non-negative matrix factorization (NMF) has been shown to be a powerful tool for clustering gene expression data, which are widely used to classify cancers. NMF aims to find two non-negative matrices whose product closely approximates the original matrix. Traditional NMF methods minimize either the l2 norm or the Kullback-Leibler distance between the product of the two matrices and the original matrix. Correntropy was recently shown to be an effective similarity measurement due to its stability to outliers or noise.Results: We propose a maximum correntropy criterion (MCC)-based NMF method (NMF-MCC) for gene expression data-based cancer clustering. Instead of minimizing the l2 norm or the Kullback-Leibler distance, NMF-MCC maximizes the correntropy between the product of the two matrices and the original matrix. The optimization problem can be solved by an expectation conditional maximization algorithm.Conclusions: Extensive experiments on six cancer benchmark sets demonstrate that the proposed method is significantly more accurate than the state-of-the-art methods in cancer clustering. 2013 Wang et al.; licensee BioMed Central Ltd.

PROCOPE, Collision Probability in Pin Clusters and Infinite Rod Lattices

International Nuclear Information System (INIS)

Amyot, L.; Daolio, C.; Benoist, P.

1984-01-01

1 - Nature of physical problem solved: Calculation of directional collision probabilities in pin clusters and infinite rod lattices. 2 - Method of solution: a) Gauss integration of analytical expressions for collision probabilities. b) alternately, an approximate closed expression (not involving integrals) may be used for pin-to-pin interactions. 3 - Restrictions on the complexity of the problem: number of fuel pins must be smaller than 62; maximum number of groups of symmetry is 300

GibbsCluster: unsupervised clustering and alignment of peptide sequences

DEFF Research Database (Denmark)

Andreatta, Massimo; Alvarez, Bruno; Nielsen, Morten

2017-01-01

motif characterizing each cluster. Several parameters are available to customize cluster analysis, including adjustable penalties for small clusters and overlapping groups and a trash cluster to remove outliers. As an example application, we used the server to deconvolute multiple specificities in large......-scale peptidome data generated by mass spectrometry. The server is available at http://www.cbs.dtu.dk/services/GibbsCluster-2.0....

Diametrical clustering for identifying anti-correlated gene clusters.

Science.gov (United States)

Dhillon, Inderjit S; Marcotte, Edward M; Roshan, Usman

2003-09-01

Clustering genes based upon their expression patterns allows us to predict gene function. Most existing clustering algorithms cluster genes together when their expression patterns show high positive correlation. However, it has been observed that genes whose expression patterns are strongly anti-correlated can also be functionally similar. Biologically, this is not unintuitive-genes responding to the same stimuli, regardless of the nature of the response, are more likely to operate in the same pathways. We present a new diametrical clustering algorithm that explicitly identifies anti-correlated clusters of genes. Our algorithm proceeds by iteratively (i). re-partitioning the genes and (ii). computing the dominant singular vector of each gene cluster; each singular vector serving as the prototype of a 'diametric' cluster. We empirically show the effectiveness of the algorithm in identifying diametrical or anti-correlated clusters. Testing the algorithm on yeast cell cycle data, fibroblast gene expression data, and DNA microarray data from yeast mutants reveals that opposed cellular pathways can be discovered with this method. We present systems whose mRNA expression patterns, and likely their functions, oppose the yeast ribosome and proteosome, along with evidence for the inverse transcriptional regulation of a number of cellular systems.

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...

The galaxy clustering crisis in abundance matching

Science.gov (United States)

Campbell, Duncan; van den Bosch, Frank C.; Padmanabhan, Nikhil; Mao, Yao-Yuan; Zentner, Andrew R.; Lange, Johannes U.; Jiang, Fangzhou; Villarreal, Antonio

2018-06-01

Galaxy clustering on small scales is significantly underpredicted by sub-halo abundance matching (SHAM) models that populate (sub-)haloes with galaxies based on peak halo mass, Mpeak. SHAM models based on the peak maximum circular velocity, Vpeak, have had much better success. The primary reason for Mpeak-based models fail is the relatively low abundance of satellite galaxies produced in these models compared to those based on Vpeak. Despite success in predicting clustering, a simple Vpeak-based SHAM model results in predictions for galaxy growth that are at odds with observations. We evaluate three possible remedies that could `save' mass-based SHAM: (1) SHAM models require a significant population of `orphan' galaxies as a result of artificial disruption/merging of sub-haloes in modern high-resolution dark matter simulations; (2) satellites must grow significantly after their accretion; and (3) stellar mass is significantly affected by halo assembly history. No solution is entirely satisfactory. However, regardless of the particulars, we show that popular SHAM models based on Mpeak cannot be complete physical models as presented. Either Vpeak truly is a better predictor of stellar mass at z ˜ 0 and it remains to be seen how the correlation between stellar mass and Vpeak comes about, or SHAM models are missing vital component(s) that significantly affect galaxy clustering.

De novo transcriptome assembly for the tropical grass Panicum maximum Jacq.

Directory of Open Access Journals (Sweden)

Guilherme Toledo-Silva

Full Text Available Guinea grass (Panicum maximum Jacq. is a tropical African grass often used to feed beef cattle, which is an important economic activity in Brazil. Brazil is the leader in global meat exportation because of its exclusively pasture-raised bovine herds. Guinea grass also has potential uses in bioenergy production due to its elevated biomass generation through the C4 photosynthesis pathway. We generated approximately 13 Gb of data from Illumina sequencing of P. maximum leaves. Four different genotypes were sequenced, and the combined reads were assembled de novo into 38,192 unigenes and annotated; approximately 63% of the unigenes had homology to other proteins in the NCBI non-redundant protein database. Functional classification through COG (Clusters of Orthologous Groups, GO (Gene Ontology and KEGG (Kyoto Encyclopedia of Genes and Genomes analyses showed that the unigenes from Guinea grass leaves are involved in a wide range of biological processes and metabolic pathways, including C4 photosynthesis and lignocellulose generation, which are important for cattle grazing and bioenergy production. The most abundant transcripts were involved in carbon fixation, photosynthesis, RNA translation and heavy metal cellular homeostasis. Finally, we identified a number of potential molecular markers, including 5,035 microsatellites (SSRs and 346,456 single nucleotide polymorphisms (SNPs. To the best of our knowledge, this is the first study to characterize the complete leaf transcriptome of P. maximum using high-throughput sequencing. The biological information provided here will aid in gene expression studies and marker-assisted selection-based breeding research in tropical grasses.

Sc-Decorated Porous Graphene for High-Capacity Hydrogen Storage: First-Principles Calculations.

Science.gov (United States)

Chen, Yuhong; Wang, Jing; Yuan, Lihua; Zhang, Meiling; Zhang, Cairong

2017-08-02

The generalized gradient approximation (GGA) function based on density functional theory is adopted to investigate the optimized geometrical structure, electron structure and hydrogen storage performance of Sc modified porous graphene (PG). It is found that the carbon ring center is the most stable adsorbed position for a single Sc atom on PG, and the maximum number of adsorbed H₂ molecules is four with the average adsorption energy of -0.429 eV/H₂. By adding a second Sc atom on the other side of the system, the hydrogen storage capacity of the system can be improved effectively. Two Sc atoms located on opposite sides of the PG carbon ring center hole is the most suitable hydrogen storage structure, and the hydrogen storage capacity reach a maximum 9.09 wt % at the average adsorption energy of -0.296 eV/H₂. The adsorption of H₂ molecules in the PG system is mainly attributed to orbital hybridization among H, Sc, and C atoms, and Coulomb attraction between negatively charged H₂ molecules and positively charged Sc atoms.

Differentiation of human-induced pluripotent stem cells into insulin-producing clusters.

Science.gov (United States)

Shaer, Anahita; Azarpira, Negar; Vahdati, Akbar; Karimi, Mohammad Hosein; Shariati, Mehrdad

2015-02-01

In diabetes mellitus type 1, beta cells are mostly destroyed; while in diabetes mellitus type 2, beta cells are reduced by 40% to 60%. We hope that soon, stem cells can be used in diabetes therapy via pancreatic beta cell replacement. Induced pluripotent stem cells are a kind of stem cell taken from an adult somatic cell by "stimulating" certain genes. These induced pluripotent stem cells may be a promising source of cell therapy. This study sought to produce isletlike clusters of insulin-producing cells taken from induced pluripotent stem cells. A human-induced pluripotent stem cell line was induced into isletlike clusters via a 4-step protocol, by adding insulin, transferrin, and selenium (ITS), N2, B27, fibroblast growth factor, and nicotinamide. During differentiation, expression of pancreatic β-cell genes was evaluated by reverse transcriptase-polymerase chain reaction; the morphologic changes of induced pluripotent stem cells toward isletlike clusters were observed by a light microscope. Dithizone staining was used to stain these isletlike clusters. Insulin produced by these clusters was evaluated by radio immunosorbent assay, and the secretion capacity was analyzed with a glucose challenge test. Differentiation was evaluated by analyzing the morphology, dithizone staining, real-time quantitative polymerase chain reaction, and immunocytochemistry. Gene expression of insulin, glucagon, PDX1, NGN3, PAX4, PAX6, NKX6.1, KIR6.2, and GLUT2 were documented by analyzing real-time quantitative polymerase chain reaction. Dithizone-stained cellular clusters were observed after 23 days. The isletlike clusters significantly produced insulin. The isletlike clusters could increase insulin secretion after a glucose challenge test. This work provides a model for studying the differentiation of human-induced pluripotent stem cells to insulin-producing cells.

Depressive Symptoms, Exercise Capacity, and Clinical Outcomes After Lung Transplantation.

Science.gov (United States)

Smith, Patrick J; Byrd, Rebecca; Lusby, Megan; Clausen, Emily; Snyder, Laurie D

2018-05-01

Depressive symptoms are common among lung transplant recipients and have been associated with worse clinical outcomes. However, few studies have examined the association between depressive symptoms assessed at multiple time points or behavioral mechanisms by which posttransplant depressive symptoms may confer greater clinical risk. We therefore examined the associations between depressive symptoms, exercise capacity, chronic lung allograft dysfunction (CLAD), and mortality prospectively in a large sample of lung transplant recipients. Between July 2009 and February 2016, 251 lung transplant recipients were assessed before transplantation and again approximately 3 weeks and 3 months after transplant. Depressive symptoms were assessed using the Centers for Epidemiologic Studies of Depression scale. Functional exercise capacity was assessed using the 6-minute walk test. Cox proportional hazards models were used to examine the associations between depressive symptoms, exercise capacity, CLAD, and mortality. During a median (range) follow-up of 4.5 (0.1 to 6.3) years, 53 participants (21%) died. Greater depressive symptoms (hazard ratio [HR] = 1.39 [95% CI = 1.05 to 1.84], p = .021) and poorer exercise capacity (HR = 0.58 [95% CI = 0.38 to 0.90], p = .021) assessed 3 months after transplant were both independently associated with mortality. Although greater depressive symptoms were associated with lower exercise capacity (β = -0.14, p = .039), exercise capacity did not mediate the association between depressive symptoms and mortality. In secondary analyses, depressive symptoms were independently predictive of CLAD (HR = 1.29 [95% CI = 1.01 to 1.65], p = .045) and the composite outcome of CLAD and mortality in a clustered event model (HR = 1.30 [1.09 to 1.56], p = .005). Depressive symptoms are associated with mortality and CLAD after lung transplantation, independent of exercise capacity.

Learning Based Approach for Optimal Clustering of Distributed Program's Call Flow Graph

Science.gov (United States)

Abofathi, Yousef; Zarei, Bager; Parsa, Saeed

Optimal clustering of call flow graph for reaching maximum concurrency in execution of distributable components is one of the NP-Complete problems. Learning automatas (LAs) are search tools which are used for solving many NP-Complete problems. In this paper a learning based algorithm is proposed to optimal clustering of call flow graph and appropriate distributing of programs in network level. The algorithm uses learning feature of LAs to search in state space. It has been shown that the speed of reaching to solution increases remarkably using LA in search process, and it also prevents algorithm from being trapped in local minimums. Experimental results show the superiority of proposed algorithm over others.

Implementation of the ALICE HLT hardware cluster finder algorithm in Vivado HLS

Energy Technology Data Exchange (ETDEWEB)

Gruell, Frederik; Engel, Heiko; Kebschull, Udo [Infrastructure and Computer Systems in Data Processing, Goethe University Frankfurt (Germany); Collaboration: ALICE-Collaboration

2016-07-01

The FastClusterFinder algorithm running in the ALICE High-Level Trigger (HLT) read-out boards extracts clusters from raw data from the Time Projection Chamber (TPC) detector and forwards them to the HLT data processing framework for tracking, event reconstruction and compression. It serves as an early stage of feature extraction in the FPGA of the board. Past and current implementations are written in VHDL on reconfigurable hardware for high throughput and low latency. We examine Vivado HLS, a high-level language that promises an increased developer productivity, as an alternative. The implementation of the application is compared to descriptions in VHDL and MaxJ in terms of productivity, resource usage and maximum clock frequency.

FlowMax: A Computational Tool for Maximum Likelihood Deconvolution of CFSE Time Courses.

Directory of Open Access Journals (Sweden)

Maxim Nikolaievich Shokhirev

Full Text Available The immune response is a concerted dynamic multi-cellular process. Upon infection, the dynamics of lymphocyte populations are an aggregate of molecular processes that determine the activation, division, and longevity of individual cells. The timing of these single-cell processes is remarkably widely distributed with some cells undergoing their third division while others undergo their first. High cell-to-cell variability and technical noise pose challenges for interpreting popular dye-dilution experiments objectively. It remains an unresolved challenge to avoid under- or over-interpretation of such data when phenotyping gene-targeted mouse models or patient samples. Here we develop and characterize a computational methodology to parameterize a cell population model in the context of noisy dye-dilution data. To enable objective interpretation of model fits, our method estimates fit sensitivity and redundancy by stochastically sampling the solution landscape, calculating parameter sensitivities, and clustering to determine the maximum-likelihood solution ranges. Our methodology accounts for both technical and biological variability by using a cell fluorescence model as an adaptor during population model fitting, resulting in improved fit accuracy without the need for ad hoc objective functions. We have incorporated our methodology into an integrated phenotyping tool, FlowMax, and used it to analyze B cells from two NFκB knockout mice with distinct phenotypes; we not only confirm previously published findings at a fraction of the expended effort and cost, but reveal a novel phenotype of nfkb1/p105/50 in limiting the proliferative capacity of B cells following B-cell receptor stimulation. In addition to complementing experimental work, FlowMax is suitable for high throughput analysis of dye dilution studies within clinical and pharmacological screens with objective and quantitative conclusions.

A biomimetic high-capacity phenazine-based anolyte for aqueous organic redox flow batteries

Science.gov (United States)

Hollas, Aaron; Wei, Xiaoliang; Murugesan, Vijayakumar; Nie, Zimin; Li, Bin; Reed, David; Liu, Jun; Sprenkle, Vincent; Wang, Wei

2018-06-01

Aqueous soluble organic (ASO) redox-active materials have recently attracted significant attention as alternatives to traditional transition metal ions in redox flow batteries (RFB). However, reported reversible capacities of ASO are often substantially lower than their theoretical values based on the reported maximum solubilities. Here, we describe a phenazine-based ASO compound with an exceptionally high reversible capacity that exceeds 90% of its theoretical value. By strategically modifying the phenazine molecular structure, we demonstrate an increased solubility from near-zero with pristine phenazine to as much as 1.8 M while also shifting its redox potential by more than 400 mV. An RFB based on a phenazine derivative (7,8-dihydroxyphenazine-2-sulfonic acid) at its near-saturation concentration exhibits an operating voltage of 1.4 V with a reversible anolyte capacity of 67 Ah l-1 and a capacity retention of 99.98% per cycle over 500 cycles.

Physical fitness and mitochondrial respiratory capacity in horse skeletal muscle.

Directory of Open Access Journals (Sweden)

Dominique-Marie Votion

Full Text Available BACKGROUND: Within the animal kingdom, horses are among the most powerful aerobic athletic mammals. Determination of muscle respiratory capacity and control improves our knowledge of mitochondrial physiology in horses and high aerobic performance in general. METHODOLOGY/PRINCIPAL FINDINGS: We applied high-resolution respirometry and multiple substrate-uncoupler-inhibitor titration protocols to study mitochondrial physiology in small (1.0-2.5 mg permeabilized muscle fibres sampled from triceps brachii of healthy horses. Oxidative phosphorylation (OXPHOS capacity (pmol O(2 • s(-1 • mg(-1 wet weight with combined Complex I and II (CI+II substrate supply (malate+glutamate+succinate increased from 77 ± 18 in overweight horses to 103 ± 18, 122 ± 15, and 129 ± 12 in untrained, trained and competitive horses (N = 3, 8, 16, and 5, respectively. Similar to human muscle mitochondria, equine OXPHOS capacity was limited by the phosphorylation system to 0.85 ± 0.10 (N = 32 of electron transfer capacity, independent of fitness level. In 15 trained horses, OXPHOS capacity increased from 119 ± 12 to 134 ± 37 when pyruvate was included in the CI+II substrate cocktail. Relative to this maximum OXPHOS capacity, Complex I (CI-linked OXPHOS capacities were only 50% with glutamate+malate, 64% with pyruvate+malate, and 68% with pyruvate+malate+glutamate, and ~78% with CII-linked succinate+rotenone. OXPHOS capacity with glutamate+malate increased with fitness relative to CI+II-supported ETS capacity from a flux control ratio of 0.38 to 0.40, 0.41 and 0.46 in overweight to competitive horses, whereas the CII/CI+II substrate control ratio remained constant at 0.70. Therefore, the apparent deficit of the CI- over CII-linked pathway capacity was reduced with physical fitness. CONCLUSIONS/SIGNIFICANCE: The scope of mitochondrial density-dependent OXPHOS capacity and the density-independent (qualitative increase of CI-linked respiratory capacity with increased

Cluster Matters

DEFF Research Database (Denmark)

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

2018-01-01

sell their products successfully in international markets, but there is also an increasingly large consumer base within India. Indeed, Indian industrial clusters have contributed to a substantial part of this growth process, and there are several hundred registered clusters within the country...... of this handbook, which focuses on the role of CSR in MSMEs. Hence we contribute to the literature on CSR in industrial clusters and specifically CSR in Indian industrial clusters by investigating the drivers of CSR in India’s industrial clusters....

Weighted Clustering

DEFF Research Database (Denmark)

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

2012-01-01

We investigate a natural generalization of the classical clustering problem, considering clustering tasks in which different instances may have different weights.We conduct the first extensive theoretical analysis on the influence of weighted data on standard clustering algorithms in both...... 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...

Multicell Downlink Capacity with Coordinated Processing

Directory of Open Access Journals (Sweden)

Roberto Padovani

2008-07-01

Full Text Available We study the potential benefits of base-station (BS cooperation for downlink transmission in multicell networks. Based on a modified Wyner-type model with users clustered at the cell-edges, we analyze the dirty-paper-coding (DPC precoder and several linear precoding schemes, including cophasing, zero-forcing (ZF, and MMSE precoders. For the nonfading scenario with random phases, we obtain analytical performance expressions for each scheme. In particular, we characterize the high signal-to-noise ratio (SNR performance gap between the DPC and ZF precoders in large networks, which indicates a singularity problem in certain network settings. Moreover, we demonstrate that the MMSE precoder does not completely resolve the singularity problem. However, by incorporating path gain fading, we numerically show that the singularity problem can be eased by linear precoding techniques aided with multiuser selection. By extending our network model to include cell-interior users, we determine the capacity regions of the two classes of users for various cooperative strategies. In addition to an outer bound and a baseline scheme, we also consider several locally cooperative transmission approaches. The resulting capacity regions show the tradeoff between the performance improvement and the requirement for BS cooperation, signal processing complexity, and channel state information at the transmitter (CSIT.

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.

Ultrathin mesoporous Co{sub 3}O{sub 4} nanosheets-constructed hierarchical clusters as high rate capability and long life anode materials for lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Wu, Shengming [Key Laboratory of Functional Inorganic Materials Chemistry, Ministry of Education, School of Chemistry, Chemical Engineering and Materials, Heilongjiang University, Heilongjiang, Harbin 150080 (China); Xia, Tian, E-mail: xiatian@hlju.edu.cn [Key Laboratory of Functional Inorganic Materials Chemistry, Ministry of Education, School of Chemistry, Chemical Engineering and Materials, Heilongjiang University, Heilongjiang, Harbin 150080 (China); Wang, Jingping [Key Laboratory of Superlight Material and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Heilongjiang, Harbin 150001 (China); Lu, Feifei [Key Laboratory of Functional Inorganic Materials Chemistry, Ministry of Education, School of Chemistry, Chemical Engineering and Materials, Heilongjiang University, Heilongjiang, Harbin 150080 (China); Xu, Chunbo [Key Laboratory of Superlight Material and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Heilongjiang, Harbin 150001 (China); Zhang, Xianfa; Huo, Lihua [Key Laboratory of Functional Inorganic Materials Chemistry, Ministry of Education, School of Chemistry, Chemical Engineering and Materials, Heilongjiang University, Heilongjiang, Harbin 150080 (China); Zhao, Hui, E-mail: zhaohui98@yahoo.com [Key Laboratory of Functional Inorganic Materials Chemistry, Ministry of Education, School of Chemistry, Chemical Engineering and Materials, Heilongjiang University, Heilongjiang, Harbin 150080 (China)

2017-06-01

Graphical abstract: Ultrathin mesoporous Co{sub 3}O{sub 4} nanosheets-constructed hierarchical clusters (UMCN-HCs) have been successfully synthesized via a facile hydrothermal method followed by a subsequent thermolysis treatment. When tested as anode materials for LIBs, UMCN-HCs achieve high reversible capacity, good long cycling life, and rate capability. - Highlights: • UMCN-HCs show high capacity, excellent stability, and good rate capability. • UMCN-HCs retain a capacity of 1067 mAh g{sup −1} after 100 cycles at 100 mA g{sup −1}. • UMCN-HCs deliver a capacity of 507 mAh g{sup −1} after 500 cycles at 2 A g{sup −1}. - Abstract: Herein, Ultrathin mesoporous Co{sub 3}O{sub 4} nanosheets-constructed hierarchical clusters (UMCN-HCs) have been successfully synthesized via a facile hydrothermal method followed by a subsequent thermolysis treatment at 600 °C in air. The products consist of cluster-like Co{sub 3}O{sub 4} microarchitectures, which are assembled by numerous ultrathin mesoporous Co{sub 3}O{sub 4} nanosheets. When tested as anode materials for lithium-ion batteries, UMCN-HCs deliver a high reversible capacity of 1067 mAh g{sup −1} at a current density of 100 mA g{sup −1} after 100 cycles. Even at 2 A g{sup −1}, a stable capacity as high as 507 mAh g{sup −1} can be achieved after 500 cycles. The high reversible capacity, excellent cycling stability, and good rate capability of UMCN-HCs may be attributed to their mesoporous sheet-like nanostructure. The sheet-layered structure of UMCN-HCs may buffer the volume change during the lithiation-delithiation process, and the mesoporous characteristic make lithium-ion transfer more easily at the interface between the active electrode and the electrolyte.

Analysis of Load-Carrying Capacity for Redundant Free-Floating Space Manipulators in Trajectory Tracking Task

Directory of Open Access Journals (Sweden)

Qingxuan Jia

2014-01-01

Full Text Available The aim of this paper is to analyze load-carrying capacity of redundant free-floating space manipulators (FFSM in trajectory tracking task. Combined with the analysis of influential factors in load-carrying process, evaluation of maximum load-carrying capacity (MLCC is described as multiconstrained nonlinear programming problem. An efficient algorithm based on repeated line search within discontinuous feasible region is presented to determine MLCC for a given trajectory of the end-effector and corresponding joint path. Then, considering the influence of MLCC caused by different initial configurations for the starting point of given trajectory, a kind of maximum payload initial configuration planning method is proposed by using PSO algorithm. Simulations are performed for a particular trajectory tracking task of the 7-DOF space manipulator, of which MLCC is evaluated quantitatively. By in-depth research of the simulation results, significant gap between the values of MLCC when using different initial configurations is analyzed, and the discontinuity of allowable load-carrying capacity is illustrated. The proposed analytical method can be taken as theoretical foundation of feasibility analysis, trajectory optimization, and optimal control of trajectory tracking task in on-orbit load-carrying operations.

Optimizing the Regional Industrial Structure Based on the Environmental Carrying Capacity: An Inexact Fuzzy Multi-Objective Programming Model

Directory of Open Access Journals (Sweden)

Wenyi Wang

2013-12-01

Full Text Available An inexact fuzzy multi-objective programming model (IFMOP based on the environmental carrying capacity is provided for industrial structure optimization problems. In the IFMOP model, both fuzzy linear programming (FLP and inexact linear programming (ILP methods are introduced into a multi-objective programming framework. It allows uncertainties to be directly communicated into the problem solving processing, and it can effectively reflect the complexity and uncertainty of an industrial system without impractical simplification. The two objective functions utilized in the optimization study are the maximum total output value and population size, and the constraints include water environmental capacity, water resource supply, atmospheric environmental capacity and energy supply. The model is subsequently employed in a realistic case for industrial development in the Tongzhou district, Beijing, China. The results demonstrate that the model can help to analyze whether the environmental carrying capacity of Tongzhou can meet the needs of the social economic objectives in the new town plan in the two scenarios and can assist decision makers in generating stable and balanced industrial structure patterns with consideration of the resources, energy and environmental constraints to meet the maximum social economic efficiency.

Chemical treatment of olive pomace: effect on acid-basic properties and metal biosorption capacity.

Science.gov (United States)

Martín-Lara, M A; Pagnanelli, F; Mainelli, S; Calero, M; Toro, L

2008-08-15

In this study, olive pomace, an agricultural waste that is very abundant in Mediterranean area, was modified by two chemical treatments in order to improve its biosorption capacity. Potentiometric titrations and IR analyses were used to characterise untreated olive pomace (OP), olive pomace treated by phosphoric acid (PAOP) and treated by hydrogen peroxide (HPOP). Acid-base properties of all investigated biosorbents were characterised by two main kinds of active sites, whose nature and concentration were determined by a mechanistic model assuming continuous distribution for the proton affinity constants. Titration modelling denoted that all investigated biosorbents (OP, PAOP and HPOP) were characterised by the same kinds of active sites (carboxylic and phenolic), but with different total concentrations with PAOP richer than OP and HPOP. Single metal equilibrium studies in batch reactors were carried out to determine the capacity of these sorbents for copper and cadmium ions at constant pH. Experimental data were analysed and compared using the Langmuir isotherm. The order of maximum uptake capacity of copper and cadmium ions on different biosorbents was PAOP>HPOP>OP. The maximum adsorption capacity of copper and cadmium, was obtained as 0.48 and 0.10 mmol/g, respectively, for PAOP. Metal biosorption tests in presence of Na(+) in solution were also carried out in order to evaluate the effect of chemical treatment on biomass selectivity. These data showed that PAOP is more selective for cadmium than the other sorbents, while similar selectivity was observed for copper.

Chemical treatment of olive pomace: Effect on acid-basic properties and metal biosorption capacity

Energy Technology Data Exchange (ETDEWEB)

Martin-Lara, M.A. [Departamento de Ingenieria Quimica, Facultad de Ciencias, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada (Spain)], E-mail: marianml@ugr.es; Pagnanelli, F. [Dipartimento di Chimica, Facolta di S.M.F.N., Universita degli Studi ' La Sapienza' , P.le A. Moro, 5, 00185 Roma (Italy)], E-mail: francesca.pagnanelli@uniroma1.it; Mainelli, S. [Dipartimento di Chimica, Facolta di S.M.F.N., Universita degli Studi ' La Sapienza' , P.le A. Moro, 5, 00185 Roma (Italy); Calero, M. [Departamento de Ingenieria Quimica, Facultad de Ciencias, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada (Spain); Toro, L. [Dipartimento di Chimica, Facolta di S.M.F.N., Universita degli Studi ' La Sapienza' , P.le A. Moro, 5, 00185 Roma (Italy)

2008-08-15

In this study, olive pomace, an agricultural waste that is very abundant in Mediterranean area, was modified by two chemical treatments in order to improve its biosorption capacity. Potentiometric titrations and IR analyses were used to characterise untreated olive pomace (OP), olive pomace treated by phosphoric acid (PAOP) and treated by hydrogen peroxide (HPOP). Acid-base properties of all investigated biosorbents were characterised by two main kinds of active sites, whose nature and concentration were determined by a mechanistic model assuming continuous distribution for the proton affinity constants. Titration modelling denoted that all investigated biosorbents (OP, PAOP and HPOP) were characterised by the same kinds of active sites (carboxylic and phenolic), but with different total concentrations with PAOP richer than OP and HPOP. Single metal equilibrium studies in batch reactors were carried out to determine the capacity of these sorbents for copper and cadmium ions at constant pH. Experimental data were analysed and compared using the Langmuir isotherm. The order of maximum uptake capacity of copper and cadmium ions on different biosorbents was PAOP > HPOP > OP. The maximum adsorption capacity of copper and cadmium, was obtained as 0.48 and 0.10 mmol/g, respectively, for PAOP. Metal biosorption tests in presence of Na{sup +} in solution were also carried out in order to evaluate the effect of chemical treatment on biomass selectivity. These data showed that PAOP is more selective for cadmium than the other sorbents, while similar selectivity was observed for copper.

Comparative Investigation of Guided Fuzzy Clustering and Mean Shift Clustering for Edge Detection in Electrical Resistivity Tomography Images of Mineral Deposits

Science.gov (United States)

Ward, Wil; Wilkinson, Paul; Chambers, Jon; Bai, Li

2014-05-01

Geophysical surveying using electrical resistivity tomography (ERT) can be used as a rapid non-intrusive method to investigate mineral deposits [1]. One of the key challenges with this approach is to find a robust automated method to assess and characterise deposits on the basis of an ERT image. Recent research applying edge detection techniques has yielded a framework that can successfully locate geological interfaces in ERT images using a minimal assumption data clustering technique, the guided fuzzy clustering method (gfcm) [2]. Non-parametric clustering techniques are statistically grounded methods of image segmentation that do not require any assumptions about the distribution of data under investigation. This study is a comparison of two such methods to assess geological structure based on the resistivity images. In addition to gfcm, a method called mean-shift clustering [3] is investigated with comparisons directed at accuracy, computational expense, and degree of user interaction. Neither approach requires the number of clusters as input (a common parameter and often impractical), rather they are based on a similar theory that data can be clustered based on peaks in the probability density function (pdf) of the data. Each local maximum in these functions represents the modal value of a particular population corresponding to a cluster and as such the data are assigned based on their relationships to these model values. The two methods differ in that gfcm approximates the pdf using kernel density estimation and identifies population means, assigning cluster membership probabilities to each resistivity value in the model based on its distance from the distribution averages. Whereas, in mean-shift clustering, the density function is not calculated, but a gradient ascent method creates a vector that leads each datum towards high density distributions iteratively using weighted kernels to calculate locally dense regions. The only parameter needed in both methods

Moderate-Load Muscular Endurance Strength Training Did Not Improve Peak Power or Functional Capacity in Older Men and Women

Directory of Open Access Journals (Sweden)

Simon Walker

2017-09-01

Full Text Available The present study determined the effects of muscular endurance strength training on maximum strength and power, functional capacity, muscle activation and hypertrophy in older men and women. Eighty-one men and women acted as an intervention group while 22 acted as non-training controls (age range 64–75 y. Intervention training included super-sets (i.e., paired exercises, immediately performing the second exercises following completion of the first with short rest intervals (30–60 s between sets at an intensity of 50–60% one-repetition maximum (1-RM for 15–20 repetitions. Concentric leg press actions measured maximum strength (1-RM and concentric peak power. Functional capacity was assessed by maximum speed walking tests (i.e., forward walk, backward walk, timed-up-and-go, and stair climb tests. Quadriceps muscle activation was assessed by surface electromyogram and twitch interpolation technique. Vastus lateralis cross-sectional area was measured by panoramic ultrasound. Compared to control, the intervention groups increased maximum strength (1-RM; men: 10 ± 7% vs. 2 ± 3%, women: 14 ± 9% vs. 1 ± 6% both P < 0.01 and vastus lateralis cross-sectional area (men: 6 ± 7% vs. −3 ± 6%, women: 10 ± 10% vs. 0 ± 4% both P < 0.05. But there were no between-group differences in peak power, muscle activation or functional capacity (e.g., stair climb; men: −5 ± 7% vs. −4 ± 3%, women: −5 ± 6% vs. −2 ± 5% both P > 0.05. While benefits occurred during muscular endurance strength training, specific stimuli are probably needed to target all aspects of age-related health.

Cosmic shear measurement with maximum likelihood and maximum a posteriori inference

Science.gov (United States)

Hall, Alex; Taylor, Andy

2017-06-01

We investigate the problem of noise bias in maximum likelihood and maximum a posteriori estimators for cosmic shear. We derive the leading and next-to-leading order biases and compute them in the context of galaxy ellipticity measurements, extending previous work on maximum likelihood inference for weak lensing. We show that a large part of the bias on these point estimators can be removed using information already contained in the likelihood when a galaxy model is specified, without the need for external calibration. We test these bias-corrected estimators on simulated galaxy images similar to those expected from planned space-based weak lensing surveys, with promising results. We find that the introduction of an intrinsic shape prior can help with mitigation of noise bias, such that the maximum a posteriori estimate can be made less biased than the maximum likelihood estimate. Second-order terms offer a check on the convergence of the estimators, but are largely subdominant. We show how biases propagate to shear estimates, demonstrating in our simple set-up that shear biases can be reduced by orders of magnitude and potentially to within the requirements of planned space-based surveys at mild signal-to-noise ratio. We find that second-order terms can exhibit significant cancellations at low signal-to-noise ratio when Gaussian noise is assumed, which has implications for inferring the performance of shear-measurement algorithms from simplified simulations. We discuss the viability of our point estimators as tools for lensing inference, arguing that they allow for the robust measurement of ellipticity and shear.

Migration in the shearing sheet and estimates for young open cluster migration

Science.gov (United States)

Quillen, Alice C.; Nolting, Eric; Minchev, Ivan; De Silva, Gayandhi; Chiappini, Cristina

2018-04-01

Using tracer particles embedded in self-gravitating shearing sheet N-body simulations, we investigate the distance in guiding centre radius that stars or star clusters can migrate in a few orbital periods. The standard deviations of guiding centre distributions and maximum migration distances depend on the Toomre or critical wavelength and the contrast in mass surface density caused by spiral structure. Comparison between our simulations and estimated guiding radii for a few young supersolar metallicity open clusters, including NGC 6583, suggests that the contrast in mass surface density in the solar neighbourhood has standard deviation (in the surface density distribution) divided by mean of about 1/4 and larger than measured using COBE data by Drimmel and Spergel. Our estimate is consistent with a standard deviation of ˜0.07 dex in the metallicities measured from high-quality spectroscopic data for 38 young open clusters (<1 Gyr) with mean galactocentric radius 7-9 kpc.

Clusters and how to make it work : toolkit for cluster strategy

NARCIS (Netherlands)

Manickam, Anu; van Berkel, Karel

2013-01-01

Clusters are the magic answer to regional economic development. Firms in clusters are more innovative; cluster policy dominates EU policy; ‘top-sectors’ and excellence are the choice of national policy makers; clusters are ‘in’. But, clusters are complex, clusters are ‘messy’; there is no clear

The success of the Uttarakhand Cluster: a case study of organisational change towards disability inclusive development.

Science.gov (United States)

Grills, Nathan; Varghese, Jubin; Hughes, Nicole; Jolly, Tamara; Kumar, Robert

2016-08-02

Persons with disability are often marginalised and excluded from international development efforts. This case study reviews the success of Uttarakhand Cluster of development NGOs in changing organisational behaviour towards being disability inclusive in their development (DID) activities. A triangulation of qualitative research methods was used, including key informant interviews, focus group discussions and review of textual data. The results synthesise data into Kotter's framework for organisational change, explaining the different stages of change experienced by the Cluster as it moved towards DID. Development of a disability mission, sharing of capacity and resources, and presence of disability champions were key in the organisations' transition towards DID. This case study demonstrates that the Cluster, a low - cost network, was able to drive organisational change and promote DID.

Making Capacity Building Meaningful: A Framework for Strategic Action

Science.gov (United States)

Robins, Lisa

2008-11-01

This paper aims to give practical meaning to ‘capacity building’ through (a) identifying a suite of practical measures, such as mentoring or best practice guidelines, that have been shown to or are considered to build human, social, institutional, and economic capital; (b) placing these measures within a broader systems framework; and (c) exploring stakeholder feedback on specific measures to inform framework implementation. The 29 measures described provide actors, whether government or nongovernment, with a suite of practical investment choices for building capacity. These measures are then clustered into eight groups according to their primary purpose and placed within a systems framework. The framework provides a tool for actors with responsibilities for or an interest in capacity building to inform more holistic and strategic targeting of effort and investment. Stakeholder feedback gathered through surveys and workshops is subsequently reported to further inform implementation of specific measures within the framework’s eight groupings. The framework presented may be built upon through the identification and inclusion of further capacity building measures. The research is conducted within the context of decentralized governance arrangements for natural resource management (NRM), with specific focus on Australia’s recently formalized 56 NRM regions and their community-based governing boards as an informative arena of learning. Application of the framework is explored in the Australian setting through the identification and comparison of measures supported and most preferred by four major stakeholder groups, namely board members, regional NRM organization staff, policy/research interests, and Indigenous interests. The research also examines stakeholder perceptions of capacity issues, and whether these issues are likely to be addressed through implementing their preferred measures.

Energetic Study of Helium Cluster Nucleation and Growth in 14YWT through First Principles

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Yingye Gan

2016-01-01

Full Text Available First principles calculations have been performed to energetically investigate the helium cluster nucleation, formation and growth behavior in the nano-structured ferritic alloy 14YWT. The helium displays strong affinity to the oxygen:vacancy (O:Vac pair. By investigating various local environments of the vacancy, we find that the energy cost for He cluster growth increases with the appearance of solutes in the reference unit. He atom tends to join the He cluster in the directions away from the solute atoms. Meanwhile, the He cluster tends to expand in the directions away from the solute atoms. A growth criterion is proposed based on the elastic instability strain of the perfect iron lattice in order to determine the maximum number of He atoms at the vacancy site. We find that up to seven He atoms can be trapped at a single vacancy. However, it is reduced to five if the vacancy is pre-occupied by an oxygen atom. Furthermore, the solute atoms within nanoclusters, such as Ti and Y, will greatly limit the growth of the He cluster. A migration energy barrier study is performed to discuss the reduced mobility of the He atom/He cluster in 14YWT.

A flexible spatial scan statistic with a restricted likelihood ratio for detecting disease clusters.

Science.gov (United States)

Tango, Toshiro; Takahashi, Kunihiko

2012-12-30

Spatial scan statistics are widely used tools for detection of disease clusters. Especially, the circular spatial scan statistic proposed by Kulldorff (1997) has been utilized in a wide variety of epidemiological studies and disease surveillance. However, as it cannot detect noncircular, irregularly shaped clusters, many authors have proposed different spatial scan statistics, including the elliptic version of Kulldorff's scan statistic. The flexible spatial scan statistic proposed by Tango and Takahashi (2005) has also been used for detecting irregularly shaped clusters. However, this method sets a feasible limitation of a maximum of 30 nearest neighbors for searching candidate clusters because of heavy computational load. In this paper, we show a flexible spatial scan statistic implemented with a restricted likelihood ratio proposed by Tango (2008) to (1) eliminate the limitation of 30 nearest neighbors and (2) to have surprisingly much less computational time than the original flexible spatial scan statistic. As a side effect, it is shown to be able to detect clusters with any shape reasonably well as the relative risk of the cluster becomes large via Monte Carlo simulation. We illustrate the proposed spatial scan statistic with data on mortality from cerebrovascular disease in the Tokyo Metropolitan area, Japan. Copyright © 2012 John Wiley & Sons, Ltd.

The study of carrying capacity of timber slabs with use the finite elements method

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Demeshok Vitalii

2017-01-01

Full Text Available In the article, the results of the study of behavior of timber slab under influence of fire with the standard “time-temperature” curve are presented. The finite element method was used for it. For the calculation we constructed a grid models of timber slabs. As a result of solution of the thermal problem was obtained temperature distribution and the graphs of maximum deflection of timber slabs and its slew rate depending on the time of the test. The obtained graphs allow to obtain data on the occurrence of the limit state of loss of bearing capacity by comparing current values of displacements and velocities with the maximum allowable. Analysis of the graphs shows that the criteria limit state of loss of bearing capacity does not occur. Calculation method of evaluating the fire resistance of timber slabs was developed. For it use database about strain-stress state of this slabs in conditions of influence of the fire.

Urban food crop production capacity and competition with the urban forest

Science.gov (United States)

Jeffrey J Richardson; L. Monika Moskal

2016-01-01

The sourcing of food plays a significant role in assessing the sustainability of a city, but it is unclear how much food a city can produce within its city limits. In this study, we propose a method for estimating the maximum food crop production capacity of a city and demonstrate the method in Seattle, WA USA by taking into account land use, the light environment, and...

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....

Large-Scale Multi-Dimensional Document Clustering on GPU Clusters

Energy Technology Data Exchange (ETDEWEB)

Cui, Xiaohui [ORNL; Mueller, Frank [North Carolina State University; Zhang, Yongpeng [ORNL; Potok, Thomas E [ORNL

2010-01-01

Document clustering plays an important role in data mining systems. Recently, a flocking-based document clustering algorithm has been proposed to solve the problem through simulation resembling the flocking behavior of birds in nature. This method is superior to other clustering algorithms, including k-means, in the sense that the outcome is not sensitive to the initial state. One limitation of this approach is that the algorithmic complexity is inherently quadratic in the number of documents. As a result, execution time becomes a bottleneck with large number of documents. In this paper, we assess the benefits of exploiting the computational power of Beowulf-like clusters equipped with contemporary Graphics Processing Units (GPUs) as a means to significantly reduce the runtime of flocking-based document clustering. Our framework scales up to over one million documents processed simultaneously in a sixteennode GPU cluster. Results are also compared to a four-node cluster with higher-end GPUs. On these clusters, we observe 30X-50X speedups, which demonstrates the potential of GPU clusters to efficiently solve massive data mining problems. Such speedups combined with the scalability potential and accelerator-based parallelization are unique in the domain of document-based data mining, to the best of our knowledge.

Membership determination of open clusters based on a spectral clustering method

Science.gov (United States)

Gao, Xin-Hua

2018-06-01

We present a spectral clustering (SC) method aimed at segregating reliable members of open clusters in multi-dimensional space. The SC method is a non-parametric clustering technique that performs cluster division using eigenvectors of the similarity matrix; no prior knowledge of the clusters is required. This method is more flexible in dealing with multi-dimensional data compared to other methods of membership determination. We use this method to segregate the cluster members of five open clusters (Hyades, Coma Ber, Pleiades, Praesepe, and NGC 188) in five-dimensional space; fairly clean cluster members are obtained. We find that the SC method can capture a small number of cluster members (weak signal) from a large number of field stars (heavy noise). Based on these cluster members, we compute the mean proper motions and distances for the Hyades, Coma Ber, Pleiades, and Praesepe clusters, and our results are in general quite consistent with the results derived by other authors. The test results indicate that the SC method is highly suitable for segregating cluster members of open clusters based on high-precision multi-dimensional astrometric data such as Gaia data.

Prediction of strontium bromide laser efficiency using cluster and decision tree analysis

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Iliev Iliycho

2018-01-01

Full Text Available Subject of investigation is a new high-powered strontium bromide (SrBr2 vapor laser emitting in multiline region of wavelengths. The laser is an alternative to the atom strontium lasers and electron free lasers, especially at the line 6.45 μm which line is used in surgery for medical processing of biological tissues and bones with minimal damage. In this paper the experimental data from measurements of operational and output characteristics of the laser are statistically processed by means of cluster analysis and tree-based regression techniques. The aim is to extract the more important relationships and dependences from the available data which influence the increase of the overall laser efficiency. There are constructed and analyzed a set of cluster models. It is shown by using different cluster methods that the seven investigated operational characteristics (laser tube diameter, length, supplied electrical power, and others and laser efficiency are combined in 2 clusters. By the built regression tree models using Classification and Regression Trees (CART technique there are obtained dependences to predict the values of efficiency, and especially the maximum efficiency with over 95% accuracy.

Performance of clustering techniques for solving multi depot vehicle routing problem

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Eliana M. Toro-Ocampo

2016-01-01

Full Text Available The vehicle routing problem considering multiple depots is classified as NP-hard. MDVRP determines simultaneously the routes of a set of vehicles and aims to meet a set of clients with a known demand. The objective function of the problem is to minimize the total distance traveled by the routes given that all customers must be served considering capacity constraints in depots and vehicles. This paper presents a hybrid methodology that combines agglomerative clustering techniques to generate initial solutions with an iterated local search algorithm (ILS to solve the problem. Although previous studies clustering methods have been proposed like strategies to generate initial solutions, in this work the search is intensified on the information generated after applying the clustering technique. Besides an extensive analysis on the performance of techniques, and their effect in the final solution is performed. The operation of the proposed methodology is feasible and effective to solve the problem regarding the quality of the answers and computational times obtained on request evaluated literature

HIV infection and hepatitis C virus genotype 1a are associated with phylogenetic clustering among people with recently acquired hepatitis C virus infection.

Science.gov (United States)

Bartlett, Sofia R; Jacka, Brendan; Bull, Rowena A; Luciani, Fabio; Matthews, Gail V; Lamoury, Francois M J; Hellard, Margaret E; Hajarizadeh, Behzad; Teutsch, Suzy; White, Bethany; Maher, Lisa; Dore, Gregory J; Lloyd, Andrew R; Grebely, Jason; Applegate, Tanya L

2016-01-01

The aim of this study was to identify factors associated with phylogenetic clustering among people with recently acquired hepatitis C virus (HCV) infection. Participants with available sample at time of HCV detection were selected from three studies; the Australian Trial in Acute Hepatitis C, the Hepatitis C Incidence and Transmission Study - Prison and Community. HCV RNA was extracted and Core to E2 region of HCV sequenced. Clusters were identified from maximum likelihood trees with 1000 bootstrap replicates using 90% bootstrap and 5% genetic distance threshold. Among 225 participants with available Core-E2 sequence (ATAHC, n=113; HITS-p, n=90; and HITS-c, n=22), HCV genotype prevalence was: G1a: 38% (n=86), G1b: 5% (n=12), G2a: 1% (n=2), G2b: 5% (n=11), G3a: 48% (n=109), G6a: 1% (n=2) and G6l 1% (n=3). Of participants included in phylogenetic trees, 22% of participants were in a pair/cluster (G1a-35%, 30/85, mean maximum genetic distance=0.031; G3a-11%, 12/106, mean maximum genetic distance=0.021; other genotypes-21%, 6/28, mean maximum genetic distance=0.023). Among HCV/HIV co-infected participants, 50% (18/36) were in a pair/cluster, compared to 16% (30/183) with HCV mono-infection (P=infection [vs. HCV mono-infection; adjusted odds ratio (AOR) 4.24; 95%CI 1.91, 9.39], and HCV G1a infection (vs. other HCV genotypes; AOR 3.33, 95%CI 0.14, 0.61).HCV treatment and prevention strategies, including enhanced antiviral therapy, should be optimised. The impact of targeting of HCV treatment as prevention to populations with higher phylogenetic clustering, such as those with HIV co-infection, could be explored through mathematical modelling. Copyright © 2015 Elsevier B.V. All rights reserved.

Space-Time Chip Equalization for Maximum Diversity Space-Time Block Coded DS-CDMA Downlink Transmission

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Petré Frederik

2004-01-01

Full Text Available In the downlink of DS-CDMA, frequency-selectivity destroys the orthogonality of the user signals and introduces multiuser interference (MUI. Space-time chip equalization is an efficient tool to restore the orthogonality of the user signals and suppress the MUI. Furthermore, multiple-input multiple-output (MIMO communication techniques can result in a significant increase in capacity. This paper focuses on space-time block coding (STBC techniques, and aims at combining STBC techniques with the original single-antenna DS-CDMA downlink scheme. This results into the so-called space-time block coded DS-CDMA downlink schemes, many of which have been presented in the past. We focus on a new scheme that enables both the maximum multiantenna diversity and the maximum multipath diversity. Although this maximum diversity can only be collected by maximum likelihood (ML detection, we pursue suboptimal detection by means of space-time chip equalization, which lowers the computational complexity significantly. To design the space-time chip equalizers, we also propose efficient pilot-based methods. Simulation results show improved performance over the space-time RAKE receiver for the space-time block coded DS-CDMA downlink schemes that have been proposed for the UMTS and IS-2000 W-CDMA standards.

Progressive Amalgamation of Building Clusters for Map Generalization Based on Scaling Subgroups

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Xianjin He

2018-03-01

Full Text Available Map generalization utilizes transformation operations to derive smaller-scale maps from larger-scale maps, and is a key procedure for the modelling and understanding of geographic space. Studies to date have largely applied a fixed tolerance to aggregate clustered buildings into a single object, resulting in the loss of details that meet cartographic constraints and may be of importance for users. This study aims to develop a method that amalgamates clustered buildings gradually without significant modification of geometry, while preserving the map details as much as possible under cartographic constraints. The amalgamation process consists of three key steps. First, individual buildings are grouped into distinct clusters by using the graph-based spatial clustering application with random forest (GSCARF method. Second, building clusters are decomposed into scaling subgroups according to homogeneity with regard to the mean distance of subgroups. Thus, hierarchies of building clusters can be derived based on scaling subgroups. Finally, an amalgamation operation is progressively performed from the bottom-level subgroups to the top-level subgroups using the maximum distance of each subgroup as the amalgamating tolerance instead of using a fixed tolerance. As a consequence of this step, generalized intermediate scaling results are available, which can form the multi-scale representation of buildings. The experimental results show that the proposed method can generate amalgams with correct details, statistical area balance and orthogonal shape while satisfying cartographic constraints (e.g., minimum distance and minimum area.

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 ...

The logistic model-generated carrying capacities, maximum ...

African Journals Online (AJOL)

This paper deals with the derivation of logistic models for cattle, sheep and goats in a commercial ranching system in Machakos District, Kenya, a savannah ecosystem with average annual rainfall of 589.3 ± 159.3mm and an area of 10 117ha. It involves modelling livestock population dynamics as discrete-time logistic ...

Farmer Health and Adaptive Capacity in the Face of Climate Change and Variability. Part 2: Contexts, Personal Attributes and Behaviors

Directory of Open Access Journals (Sweden)

Helen Berry

2011-10-01

Full Text Available This study extends the emerging body of research on farmer adaptation to climate change, by segmenting farmers on the basis of specific attributes (health, values, belief about climate change, sense of responsibility for climate change, desire to change, social, human and financial capitals and farmer demographics and considering such attributes as critical social aspects of the contextualized capacity to adapt. The segmental analysis was based on a nationally representative sample of 3,993 farmers concerned with farmer adaptation of climate risks. The resulting data were subjected to two-step cluster analysis to identify homogenous groups of farmers based on factors related to climate change adaptation. A three-cluster solution was identified wherein farmers were distinguishable on the basis of belief in climate change, desire for financial assistance and advice, social connectedness, information seeking, and adverse farm conditions. The largest group (Cluster 1: 55% was characterized by farmers who recognized being affected by drought and drying and who were actively engaged in adaptive practices, despite the fact that they had little income and poor farm resources. One third of these farmers reported that their health was a barrier to sustained activity in farming. Cluster 2 (26% was characterized by farmers not readily affected by drying, who enjoyed good incomes, good health and better farming conditions. They expressed little desire to adapt. The smallest cluster (Cluster 3: 19% was also characterized by farmers who recognized that they were affected by drying. However, despite a desire to adapt, they had very little means to do so. They reported the poorest natural resources and the poorest health, despite being younger. The findings suggest that it is the intent to adapt, starting from where people are at, which is a more important indicator of the capacity to work towards sustainable practices than assets tests alone.

Modelling of extreme rainfall events in Peninsular Malaysia based on annual maximum and partial duration series

Science.gov (United States)

Zin, Wan Zawiah Wan; Shinyie, Wendy Ling; Jemain, Abdul Aziz

2015-02-01

In this study, two series of data for extreme rainfall events are generated based on Annual Maximum and Partial Duration Methods, derived from 102 rain-gauge stations in Peninsular from 1982-2012. To determine the optimal threshold for each station, several requirements must be satisfied and Adapted Hill estimator is employed for this purpose. A semi-parametric bootstrap is then used to estimate the mean square error (MSE) of the estimator at each threshold and the optimal threshold is selected based on the smallest MSE. The mean annual frequency is also checked to ensure that it lies in the range of one to five and the resulting data is also de-clustered to ensure independence. The two data series are then fitted to Generalized Extreme Value and Generalized Pareto distributions for annual maximum and partial duration series, respectively. The parameter estimation methods used are the Maximum Likelihood and the L-moment methods. Two goodness of fit tests are then used to evaluate the best-fitted distribution. The results showed that the Partial Duration series with Generalized Pareto distribution and Maximum Likelihood parameter estimation provides the best representation for extreme rainfall events in Peninsular Malaysia for majority of the stations studied. Based on these findings, several return values are also derived and spatial mapping are constructed to identify the distribution characteristic of extreme rainfall in Peninsular Malaysia.

Analysis of Carrying Capacity of Agro-Ecosystem Coconut-Cattle in South Minahasa Regency

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AHS Salendu

2012-01-01

Full Text Available Abstract. Coconut plantation is very dominating in South Minahasa regency seen from its production of 49,907.33 tons in 2010. The land under coconut trees can be used for food crops or forage. The waste from food crops is the source of animal feed, while the livestock’s manure is used to improve soil fertility under coconut tree. The research objective was to analyse the carrying capacity of the agro-ecosystem of coconut-cattle. Regency and district were determined purposively. A total of 86 farmers as respondents were determined based on the ownership of at least 2 cattle and cattle selling experience. Data were analyzed using effective potential of livestock development and land capability index (IDD. The result showed that the maximum potential of land resources (PMSL was 30,872.94 animal unit (AU. The capacity increase in cattle population based on the soil resources was 18,208.94 AU. The maximum potential based on farmer house holds was 127,023.00 AU. The value of land capability index was 2.14. The conclusion was South Minahasa Regency was still potential for cattle development regarding land resources or workforce potentials. Development of cattle can be integrated with the coconut to maintain and improve agro-ecosystem sustainability of coconut plantation. Keywords: cattle, carrying capacity, agro-ecosystem, coconut Animal Production 14(1:56-62, January 2012

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

Virtual screening by a new Clustering-based Weighted Similarity Extreme Learning Machine approach.

Science.gov (United States)

Pasupa, Kitsuchart; Kudisthalert, Wasu

2018-01-01

Machine learning techniques are becoming popular in virtual screening tasks. One of the powerful machine learning algorithms is Extreme Learning Machine (ELM) which has been applied to many applications and has recently been applied to virtual screening. We propose the Weighted Similarity ELM (WS-ELM) which is based on a single layer feed-forward neural network in a conjunction of 16 different similarity coefficients as activation function in the hidden layer. It is known that the performance of conventional ELM is not robust due to random weight selection in the hidden layer. Thus, we propose a Clustering-based WS-ELM (CWS-ELM) that deterministically assigns weights by utilising clustering algorithms i.e. k-means clustering and support vector clustering. The experiments were conducted on one of the most challenging datasets-Maximum Unbiased Validation Dataset-which contains 17 activity classes carefully selected from PubChem. The proposed algorithms were then compared with other machine learning techniques such as support vector machine, random forest, and similarity searching. The results show that CWS-ELM in conjunction with support vector clustering yields the best performance when utilised together with Sokal/Sneath(1) coefficient. Furthermore, ECFP_6 fingerprint presents the best results in our framework compared to the other types of fingerprints, namely ECFP_4, FCFP_4, and FCFP_6.

Massively parallel unsupervised single-particle cryo-EM data clustering via statistical manifold learning.

Directory of Open Access Journals (Sweden)

Jiayi Wu

Full Text Available Structural heterogeneity in single-particle cryo-electron microscopy (cryo-EM data represents a major challenge for high-resolution structure determination. Unsupervised classification may serve as the first step in the assessment of structural heterogeneity. However, traditional algorithms for unsupervised classification, such as K-means clustering and maximum likelihood optimization, may classify images into wrong classes with decreasing signal-to-noise-ratio (SNR in the image data, yet demand increased computational costs. Overcoming these limitations requires further development of clustering algorithms for high-performance cryo-EM data processing. Here we introduce an unsupervised single-particle clustering algorithm derived from a statistical manifold learning framework called generative topographic mapping (GTM. We show that unsupervised GTM clustering improves classification accuracy by about 40% in the absence of input references for data with lower SNRs. Applications to several experimental datasets suggest that our algorithm can detect subtle structural differences among classes via a hierarchical clustering strategy. After code optimization over a high-performance computing (HPC environment, our software implementation was able to generate thousands of reference-free class averages within hours in a massively parallel fashion, which allows a significant improvement on ab initio 3D reconstruction and assists in the computational purification of homogeneous datasets for high-resolution visualization.

Massively parallel unsupervised single-particle cryo-EM data clustering via statistical manifold learning.

Science.gov (United States)

Wu, Jiayi; Ma, Yong-Bei; Congdon, Charles; Brett, Bevin; Chen, Shuobing; Xu, Yaofang; Ouyang, Qi; Mao, Youdong

2017-01-01

Structural heterogeneity in single-particle cryo-electron microscopy (cryo-EM) data represents a major challenge for high-resolution structure determination. Unsupervised classification may serve as the first step in the assessment of structural heterogeneity. However, traditional algorithms for unsupervised classification, such as K-means clustering and maximum likelihood optimization, may classify images into wrong classes with decreasing signal-to-noise-ratio (SNR) in the image data, yet demand increased computational costs. Overcoming these limitations requires further development of clustering algorithms for high-performance cryo-EM data processing. Here we introduce an unsupervised single-particle clustering algorithm derived from a statistical manifold learning framework called generative topographic mapping (GTM). We show that unsupervised GTM clustering improves classification accuracy by about 40% in the absence of input references for data with lower SNRs. Applications to several experimental datasets suggest that our algorithm can detect subtle structural differences among classes via a hierarchical clustering strategy. After code optimization over a high-performance computing (HPC) environment, our software implementation was able to generate thousands of reference-free class averages within hours in a massively parallel fashion, which allows a significant improvement on ab initio 3D reconstruction and assists in the computational purification of homogeneous datasets for high-resolution visualization.

An entropy theorem for computing the capacity of weakly (d, k)-constrained sequences

NARCIS (Netherlands)

Janssen, A.J.E.M.; Schouhamer Immink, K.A.

2000-01-01

We find an analytic expression for the maximum of the normalized entropy -SieTpiln pi/SieTipi where the set T is the disjoint union of sets Sn of positive integers that are assigned probabilities Pn, SnPn =1. This result is applied to the computation of the capacity of weakly (d,k)-constrained

Cross-layer cluster-based energy-efficient protocol for wireless sensor networks.

Science.gov (United States)

Mammu, Aboobeker Sidhik Koyamparambil; Hernandez-Jayo, Unai; Sainz, Nekane; de la Iglesia, Idoia

2015-04-09

Recent developments in electronics and wireless communications have enabled the improvement of low-power and low-cost wireless sensors networks (WSNs). One of the most important challenges in WSNs is to increase the network lifetime due to the limited energy capacity of the network nodes. Another major challenge in WSNs is the hot spots that emerge as locations under heavy traffic load. Nodes in such areas quickly drain energy resources, leading to disconnection in network services. In such an environment, cross-layer cluster-based energy-efficient algorithms (CCBE) can prolong the network lifetime and energy efficiency. CCBE is based on clustering the nodes to different hexagonal structures. A hexagonal cluster consists of cluster members (CMs) and a cluster head (CH). The CHs are selected from the CMs based on nodes near the optimal CH distance and the residual energy of the nodes. Additionally, the optimal CH distance that links to optimal energy consumption is derived. To balance the energy consumption and the traffic load in the network, the CHs are rotated among all CMs. In WSNs, energy is mostly consumed during transmission and reception. Transmission collisions can further decrease the energy efficiency. These collisions can be avoided by using a contention-free protocol during the transmission period. Additionally, the CH allocates slots to the CMs based on their residual energy to increase sleep time. Furthermore, the energy consumption of CH can be further reduced by data aggregation. In this paper, we propose a data aggregation level based on the residual energy of CH and a cost-aware decision scheme for the fusion of data. Performance results show that the CCBE scheme performs better in terms of network lifetime, energy consumption and throughput compared to low-energy adaptive clustering hierarchy (LEACH) and hybrid energy-efficient distributed clustering (HEED).

Cross-Layer Cluster-Based Energy-Efficient Protocol for Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Aboobeker Sidhik Koyamparambil Mammu

2015-04-01

Full Text Available Recent developments in electronics and wireless communications have enabled the improvement of low-power and low-cost wireless sensors networks (WSNs. One of the most important challenges in WSNs is to increase the network lifetime due to the limited energy capacity of the network nodes. Another major challenge in WSNs is the hot spots that emerge as locations under heavy traffic load. Nodes in such areas quickly drain energy resources, leading to disconnection in network services. In such an environment, cross-layer cluster-based energy-efficient algorithms (CCBE can prolong the network lifetime and energy efficiency. CCBE is based on clustering the nodes to different hexagonal structures. A hexagonal cluster consists of cluster members (CMs and a cluster head (CH. The CHs are selected from the CMs based on nodes near the optimal CH distance and the residual energy of the nodes. Additionally, the optimal CH distance that links to optimal energy consumption is derived. To balance the energy consumption and the traffic load in the network, the CHs are rotated among all CMs. In WSNs, energy is mostly consumed during transmission and reception. Transmission collisions can further decrease the energy efficiency. These collisions can be avoided by using a contention-free protocol during the transmission period. Additionally, the CH allocates slots to the CMs based on their residual energy to increase sleep time. Furthermore, the energy consumption of CH can be further reduced by data aggregation. In this paper, we propose a data aggregation level based on the residual energy of CH and a cost-aware decision scheme for the fusion of data. Performance results show that the CCBE scheme performs better in terms of network lifetime, energy consumption and throughput compared to low-energy adaptive clustering hierarchy (LEACH and hybrid energy-efficient distributed clustering (HEED.

clusterMaker: a multi-algorithm clustering plugin for Cytoscape

Directory of Open Access Journals (Sweden)

Morris John H

2011-11-01

Full Text Available Abstract Background In the post-genomic era, the rapid increase in high-throughput data calls for computational tools capable of integrating data of diverse types and facilitating recognition of biologically meaningful patterns within them. For example, protein-protein interaction data sets have been clustered to identify stable complexes, but scientists lack easily accessible tools to facilitate combined analyses of multiple data sets from different types of experiments. Here we present clusterMaker, a Cytoscape plugin that implements several clustering algorithms and provides network, dendrogram, and heat map views of the results. The Cytoscape network is linked to all of the other views, so that a selection in one is immediately reflected in the others. clusterMaker is the first Cytoscape plugin to implement such a wide variety of clustering algorithms and visualizations, including the only implementations of hierarchical clustering, dendrogram plus heat map visualization (tree view, k-means, k-medoid, SCPS, AutoSOME, and native (Java MCL. Results Results are presented in the form of three scenarios of use: analysis of protein expression data using a recently published mouse interactome and a mouse microarray data set of nearly one hundred diverse cell/tissue types; the identification of protein complexes in the yeast Saccharomyces cerevisiae; and the cluster analysis of the vicinal oxygen chelate (VOC enzyme superfamily. For scenario one, we explore functionally enriched mouse interactomes specific to particular cellular phenotypes and apply fuzzy clustering. For scenario two, we explore the prefoldin complex in detail using both physical and genetic interaction clusters. For scenario three, we explore the possible annotation of a protein as a methylmalonyl-CoA epimerase within the VOC superfamily. Cytoscape session files for all three scenarios are provided in the Additional Files section. Conclusions The Cytoscape plugin cluster

Morning reduction of photosynthetic capacity before midday depression.

Science.gov (United States)

Koyama, Kohei; Takemoto, Shuhei

2014-03-17

Midday depression of photosynthesis has important consequences for ecosystem carbon exchange. Recent studies of forest trees have demonstrated that latent reduction of photosynthetic capacity can begin in the early morning, preceding the midday depression. We investigated whether such early morning reduction also occurs in an herbaceous species, Oenothera biennis. Diurnal changes of the photosynthetic light response curve (measured using a light-emitting diode) and incident sunlight intensity were measured under field conditions. The following results were obtained: (1) the light-saturated photosynthetic rate decreased beginning at sunrise; (2) the incident sunlight intensity on the leaves increased from sunrise; and (3) combining (1) and (2), the net photosynthetic rate under natural sunlight intensity increased from sunrise, reached a maximum at mid-morning, and then showed midday depression. Our results demonstrate that the latent morning reduction of photosynthetic capacity begins at sunrise, preceding the apparent midday depression, in agreement with previous studies of forest trees.

Application of 2D and 3D image technologies to characterise morphological attributes of grapevine clusters.

Science.gov (United States)

Tello, Javier; Cubero, Sergio; Blasco, José; Tardaguila, Javier; Aleixos, Nuria; Ibáñez, Javier

2016-10-01

Grapevine cluster morphology influences the quality and commercial value of wine and table grapes. It is routinely evaluated by subjective and inaccurate methods that do not meet the requirements set by the food industry. Novel two-dimensional (2D) and three-dimensional (3D) machine vision technologies emerge as promising tools for its automatic and fast evaluation. The automatic evaluation of cluster length, width and elongation was successfully achieved by the analysis of 2D images, significant and strong correlations with the manual methods being found (r = 0.959, 0.861 and 0.852, respectively). The classification of clusters according to their shape can be achieved by evaluating their conicity in different sections of the cluster. The geometric reconstruction of the morphological volume of the cluster from 2D features worked better than the direct 3D laser scanning system, showing a high correlation (r = 0.956) with the manual approach (water displacement method). In addition, we constructed and validated a simple linear regression model for cluster compactness estimation. It showed a high predictive capacity for both the training and validation subsets of clusters (R(2)  = 84.5 and 71.1%, respectively). The methodologies proposed in this work provide continuous and accurate data for the fast and objective characterisation of cluster morphology. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Relevant Subspace Clustering

DEFF Research Database (Denmark)

Müller, Emmanuel; Assent, Ira; Günnemann, Stephan

2009-01-01

Subspace clustering aims at detecting clusters in any subspace projection of a high dimensional space. As the number of possible subspace projections is exponential in the number of dimensions, the result is often tremendously large. Recent approaches fail to reduce results to relevant subspace...... clusters. Their results are typically highly redundant, i.e. many clusters are detected multiple times in several projections. In this work, we propose a novel model for relevant subspace clustering (RESCU). We present a global optimization which detects the most interesting non-redundant subspace clusters...... achieves top clustering quality while competing approaches show greatly varying performance....

IGSA: Individual Gene Sets Analysis, including Enrichment and Clustering.

Science.gov (United States)

Wu, Lingxiang; Chen, Xiujie; Zhang, Denan; Zhang, Wubing; Liu, Lei; Ma, Hongzhe; Yang, Jingbo; Xie, Hongbo; Liu, Bo; Jin, Qing

2016-01-01

Analysis of gene sets has been widely applied in various high-throughput biological studies. One weakness in the traditional methods is that they neglect the heterogeneity of genes expressions in samples which may lead to the omission of some specific and important gene sets. It is also difficult for them to reflect the severities of disease and provide expression profiles of gene sets for individuals. We developed an application software called IGSA that leverages a powerful analytical capacity in gene sets enrichment and samples clustering. IGSA calculates gene sets expression scores for each sample and takes an accumulating clustering strategy to let the samples gather into the set according to the progress of disease from mild to severe. We focus on gastric, pancreatic and ovarian cancer data sets for the performance of IGSA. We also compared the results of IGSA in KEGG pathways enrichment with David, GSEA, SPIA, ssGSEA and analyzed the results of IGSA clustering and different similarity measurement methods. Notably, IGSA is proved to be more sensitive and specific in finding significant pathways, and can indicate related changes in pathways with the severity of disease. In addition, IGSA provides with significant gene sets profile for each sample.

Maximum Acceleration Recording Circuit

Science.gov (United States)

Bozeman, Richard J., Jr.

1995-01-01

Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

Horticultural cluster

OpenAIRE

SHERSTIUK S.V.; POSYLAYEVA K.I.

2013-01-01

In the article there are the theoretical and methodological approaches to the nature and existence of the cluster. The cluster differences from other kinds of cooperative and integration associations. Was develop by scientific-practical recommendations for forming a competitive horticultur cluster.

Potential and limits to cluster-state quantum computing using probabilistic gates

International Nuclear Information System (INIS)

Gross, D.; Kieling, K.; Eisert, J.

2006-01-01

We establish bounds to the necessary resource consumption when building up cluster states for one-way computing using probabilistic gates. Emphasis is put on state preparation with linear optical gates, as the probabilistic character is unavoidable here. We identify rigorous general bounds to the necessary consumption of initially available maximally entangled pairs when building up one-dimensional cluster states with individually acting linear optical quantum gates, entangled pairs, and vacuum modes. As the known linear optics gates have a limited maximum success probability, as we show, this amounts to finding the optimal classical strategy of fusing pieces of linear cluster states. A formal notion of classical configurations and strategies is introduced for probabilistic nonfaulty gates. We study the asymptotic performance of strategies that can be simply described, and prove ultimate bounds to the performance of the globally optimal strategy. The arguments employ methods of random walks and convex optimization. This optimal strategy is also the one that requires the shortest storage time, and necessitates the fewest invocations of probabilistic gates. For two-dimensional cluster states, we find, for any elementary success probability, an essentially deterministic preparation of a cluster state with quadratic, hence optimal, asymptotic scaling in the use of entangled pairs. We also identify a percolation effect in state preparation, in that from a threshold probability on, almost all preparations will be either successful or fail. We outline the implications on linear optical architectures and fault-tolerant computations

New method for reconstruction of star spatial distribution in globular clusters and its application to flare stars in Pleiades

International Nuclear Information System (INIS)

Kosarev, E.L.

1980-01-01

A new method to reconstruct spatial star distribution in globular clusters is presented. The method gives both the estimation of unknown spatial distribution and the probable reconstruction error. This error has statistical origin and depends only on the number of stars in a cluster. The method is applied to reconstruct the spatial density of 441 flare stars in Pleiades. The spatial density has a maximum in the centre of the cluster of about 1.6-2.5 pc -3 and with increasing distance from the center smoothly falls down to zero approximately with the Gaussian law with a scale parameter of 3.5 pc

Hybrid Heat Capacity - Moving Slab Laser Concept

International Nuclear Information System (INIS)

Stappaerts, E A

2002-01-01

A hybrid configuration of a heat capacity laser (HCL) and a moving slab laser (MSL) has been studied. Multiple volumes of solid-state laser material are sequentially diode-pumped and their energy extracted. When a volume reaches a maximum temperature after a ''sub-magazine depth'', it is moved out of the pumping region into a cooling region, and a new volume is introduced. The total magazine depth equals the submagazine depth times the number of volumes. The design parameters are chosen to provide high duty factor operation, resulting in effective use of the diode arrays. The concept significantly reduces diode array cost over conventional heat capacity lasers, and it is considered enabling for many potential applications. A conceptual design study of the hybrid configuration has been carried out. Three concepts were evaluated using CAD tools. The concepts are described and their relative merits discussed. Because of reduced disk size and diode cost, the hybrid concept may allow scaling to average powers on the order of 0.5 MW/module

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...

Neutron spectra unfolding with maximum entropy and maximum likelihood

International Nuclear Information System (INIS)

Itoh, Shikoh; Tsunoda, Toshiharu

1989-01-01

A new unfolding theory has been established on the basis of the maximum entropy principle and the maximum likelihood method. This theory correctly embodies the Poisson statistics of neutron detection, and always brings a positive solution over the whole energy range. Moreover, the theory unifies both problems of overdetermined and of underdetermined. For the latter, the ambiguity in assigning a prior probability, i.e. the initial guess in the Bayesian sense, has become extinct by virtue of the principle. An approximate expression of the covariance matrix for the resultant spectra is also presented. An efficient algorithm to solve the nonlinear system, which appears in the present study, has been established. Results of computer simulation showed the effectiveness of the present theory. (author)

Maximum Power from a Solar Panel

Directory of Open Access Journals (Sweden)

Michael Miller

2010-01-01

Full Text Available Solar energy has become a promising alternative to conventional fossil fuel sources. Solar panels are used to collect solar radiation and convert it into electricity. One of the techniques used to maximize the effectiveness of this energy alternative is to maximize the power output of the solar collector. In this project the maximum power is calculated by determining the voltage and the current of maximum power. These quantities are determined by finding the maximum value for the equation for power using differentiation. After the maximum values are found for each time of day, each individual quantity, voltage of maximum power, current of maximum power, and maximum power is plotted as a function of the time of day.

Voting-based consensus clustering for combining multiple clusterings of chemical structures

Directory of Open Access Journals (Sweden)

Saeed Faisal

2012-12-01

Full Text Available Abstract Background Although many consensus clustering methods have been successfully used for combining multiple classifiers in many areas such as machine learning, applied statistics, pattern recognition and bioinformatics, few consensus clustering methods have been applied for combining multiple clusterings of chemical structures. It is known that any individual clustering method will not always give the best results for all types of applications. So, in this paper, three voting and graph-based consensus clusterings were used for combining multiple clusterings of chemical structures to enhance the ability of separating biologically active molecules from inactive ones in each cluster. Results The cumulative voting-based aggregation algorithm (CVAA, cluster-based similarity partitioning algorithm (CSPA and hyper-graph partitioning algorithm (HGPA were examined. The F-measure and Quality Partition Index method (QPI were used to evaluate the clusterings and the results were compared to the Ward’s clustering method. The MDL Drug Data Report (MDDR dataset was used for experiments and was represented by two 2D fingerprints, ALOGP and ECFP_4. The performance of voting-based consensus clustering method outperformed the Ward’s method using F-measure and QPI method for both ALOGP and ECFP_4 fingerprints, while the graph-based consensus clustering methods outperformed the Ward’s method only for ALOGP using QPI. The Jaccard and Euclidean distance measures were the methods of choice to generate the ensembles, which give the highest values for both criteria. Conclusions The results of the experiments show that consensus clustering methods can improve the effectiveness of chemical structures clusterings. The cumulative voting-based aggregation algorithm (CVAA was the method of choice among consensus clustering methods.

What is the carrying capacity for fish in the ocean? A meta analysis of population dynamics of North Atlantic cod

DEFF Research Database (Denmark)

Myers, R.A.; MacKenzie, Brian; Bowen, K.G.

2001-01-01

used empirical Bayes techniques to estimate the maximum reproductive rate and carrying capacity of each stock. In all cases, the empirical Bayes estimates were biologically reasonable, whereas a stock by stock analysis occasionally yielded nonsensical parameter estimates (e.g., infinite values). Our...... analysis showed that the carrying capacity per unit area varied by more than 20-fold among populations and that much of this variation was related to temperature. That is, the carrying capacity per square kilometre declines as temperature increases....

Management of Energy Consumption on Cluster Based Routing Protocol for MANET

Science.gov (United States)

Hosseini-Seno, Seyed-Amin; Wan, Tat-Chee; Budiarto, Rahmat; Yamada, Masashi

The usage of light-weight mobile devices is increasing rapidly, leading to demand for more telecommunication services. Consequently, mobile ad hoc networks and their applications have become feasible with the proliferation of light-weight mobile devices. Many protocols have been developed to handle service discovery and routing in ad hoc networks. However, the majority of them did not consider one critical aspect of this type of network, which is the limited of available energy in each node. Cluster Based Routing Protocol (CBRP) is a robust/scalable routing protocol for Mobile Ad hoc Networks (MANETs) and superior to existing protocols such as Ad hoc On-demand Distance Vector (AODV) in terms of throughput and overhead. Therefore, based on this strength, methods to increase the efficiency of energy usage are incorporated into CBRP in this work. In order to increase the stability (in term of life-time) of the network and to decrease the energy consumption of inter-cluster gateway nodes, an Enhanced Gateway Cluster Based Routing Protocol (EGCBRP) is proposed. Three methods have been introduced by EGCBRP as enhancements to the CBRP: improving the election of cluster Heads (CHs) in CBRP which is based on the maximum available energy level, implementing load balancing for inter-cluster traffic using multiple gateways, and implementing sleep state for gateway nodes to further save the energy. Furthermore, we propose an Energy Efficient Cluster Based Routing Protocol (EECBRP) which extends the EGCBRP sleep state concept into all idle member nodes, excluding the active nodes in all clusters. The experiment results show that the EGCBRP decreases the overall energy consumption of the gateway nodes up to 10% and the EECBRP reduces the energy consumption of the member nodes up to 60%, both of which in turn contribute to stabilizing the network.

OBSERVED SCALING RELATIONS FOR STRONG LENSING CLUSTERS: CONSEQUENCES FOR COSMOLOGY AND CLUSTER ASSEMBLY

International Nuclear Information System (INIS)

Comerford, Julia M.; Moustakas, Leonidas A.; Natarajan, Priyamvada

2010-01-01

Scaling relations of observed galaxy cluster properties are useful tools for constraining cosmological parameters as well as cluster formation histories. One of the key cosmological parameters, σ 8 , is constrained using observed clusters of galaxies, although current estimates of σ 8 from the scaling relations of dynamically relaxed galaxy clusters are limited by the large scatter in the observed cluster mass-temperature (M-T) relation. With a sample of eight strong lensing clusters at 0.3 8 , but combining the cluster concentration-mass relation with the M-T relation enables the inclusion of unrelaxed clusters as well. Thus, the resultant gains in the accuracy of σ 8 measurements from clusters are twofold: the errors on σ 8 are reduced and the cluster sample size is increased. Therefore, the statistics on σ 8 determination from clusters are greatly improved by the inclusion of unrelaxed clusters. Exploring cluster scaling relations further, we find that the correlation between brightest cluster galaxy (BCG) luminosity and cluster mass offers insight into the assembly histories of clusters. We find preliminary evidence for a steeper BCG luminosity-cluster mass relation for strong lensing clusters than the general cluster population, hinting that strong lensing clusters may have had more active merging histories.

Cluster Headache

OpenAIRE

Pearce, Iris

1985-01-01

Cluster headache is the most severe primary headache with recurrent pain attacks described as worse than giving birth. The aim of this paper was to make an overview of current knowledge on cluster headache with a focus on pathophysiology and treatment. This paper presents hypotheses of cluster headache pathophysiology, current treatment options and possible future therapy approaches. For years, the hypothalamus was regarded as the key structure in cluster headache, but is now thought to be pa...