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Sample records for ball-scale based hierarchical

  1. Ball-Scale Based Hierarchical Multi-Object Recognition in 3D Medical Images

    CERN Document Server

    Bagci, Ulas; Chen, Xinjian

    2010-01-01

    This paper investigates, using prior shape models and the concept of ball scale (b-scale), ways of automatically recognizing objects in 3D images without performing elaborate searches or optimization. That is, the goal is to place the model in a single shot close to the right pose (position, orientation, and scale) in a given image so that the model boundaries fall in the close vicinity of object boundaries in the image. This is achieved via the following set of key ideas: (a) A semi-automatic way of constructing a multi-object shape model assembly. (b) A novel strategy of encoding, via b-scale, the pose relationship between objects in the training images and their intensity patterns captured in b-scale images. (c) A hierarchical mechanism of positioning the model, in a one-shot way, in a given image from a knowledge of the learnt pose relationship and the b-scale image of the given image to be segmented. The evaluation results on a set of 20 routine clinical abdominal female and male CT data sets indicate th...

  2. Ball-scale based hierarchical multi-object recognition in 3D medical images

    Science.gov (United States)

    Bağci, Ulas; Udupa, Jayaram K.; Chen, Xinjian

    2010-03-01

    This paper investigates, using prior shape models and the concept of ball scale (b-scale), ways of automatically recognizing objects in 3D images without performing elaborate searches or optimization. That is, the goal is to place the model in a single shot close to the right pose (position, orientation, and scale) in a given image so that the model boundaries fall in the close vicinity of object boundaries in the image. This is achieved via the following set of key ideas: (a) A semi-automatic way of constructing a multi-object shape model assembly. (b) A novel strategy of encoding, via b-scale, the pose relationship between objects in the training images and their intensity patterns captured in b-scale images. (c) A hierarchical mechanism of positioning the model, in a one-shot way, in a given image from a knowledge of the learnt pose relationship and the b-scale image of the given image to be segmented. The evaluation results on a set of 20 routine clinical abdominal female and male CT data sets indicate the following: (1) Incorporating a large number of objects improves the recognition accuracy dramatically. (2) The recognition algorithm can be thought as a hierarchical framework such that quick replacement of the model assembly is defined as coarse recognition and delineation itself is known as finest recognition. (3) Scale yields useful information about the relationship between the model assembly and any given image such that the recognition results in a placement of the model close to the actual pose without doing any elaborate searches or optimization. (4) Effective object recognition can make delineation most accurate.

  3. Ball-Scale Based Hierarchical Multi-Object Recognition in 3D Medical Images

    OpenAIRE

    Bagci, Ulas; Udupa, Jayaram K.; Chen, Xinjian

    2010-01-01

    This paper investigates, using prior shape models and the concept of ball scale (b-scale), ways of automatically recognizing objects in 3D images without performing elaborate searches or optimization. That is, the goal is to place the model in a single shot close to the right pose (position, orientation, and scale) in a given image so that the model boundaries fall in the close vicinity of object boundaries in the image. This is achieved via the following set of key ideas: (a) A semi-automati...

  4. Hierarchical Identity-Based Lossy Trapdoor Functions

    CERN Document Server

    Escala, Alex; Libert, Benoit; Rafols, Carla

    2012-01-01

    Lossy trapdoor functions, introduced by Peikert and Waters (STOC'08), have received a lot of attention in the last years, because of their wide range of applications in theoretical cryptography. The notion has been recently extended to the identity-based scenario by Bellare et al. (Eurocrypt'12). We provide one more step in this direction, by considering the notion of hierarchical identity-based lossy trapdoor functions (HIB-LTDFs). Hierarchical identity-based cryptography generalizes identitybased cryptography in the sense that identities are organized in a hierarchical way; a parent identity has more power than its descendants, because it can generate valid secret keys for them. Hierarchical identity-based cryptography has been proved very useful both for practical applications and to establish theoretical relations with other cryptographic primitives. In order to realize HIB-LTDFs, we first build a weakly secure hierarchical predicate encryption scheme. This scheme, which may be of independent interest, is...

  5. Timed-Release Hierarchical Identity-Based Encryption

    Directory of Open Access Journals (Sweden)

    Toru Oshikiri

    2014-11-01

    Full Text Available We propose a notion of hierarchical identity-based encryption (HIBE scheme with timed-release encryption (TRE mechanism, timed-release hierarchical identity-based encryption (TRHIBE, and define its security models. We also show a generic construction of TRHIBE from HIBE and one-time signature, and discuss the security of the constructed scheme.

  6. A Hierarchical Clustering Based Approach in Aspect Mining

    OpenAIRE

    Gabriela Czibula; Grigoreta Sofia Cojocar

    2012-01-01

    A Hierarchical Clustering Based Approach in Aspect Mining Clustering is a division of data into groups of similar objects. Aspect mining is a process that tries to identify crosscutting concerns in existing software systems. The goal is to refactor the existing systems to use aspect oriented programming, in order to make them easier to maintain and to evolve. The aim of this paper is to present a new hierarchical clustering based approach in aspect mining. For this purpose we propose HAC algo...

  7. Articulated Pose Estimation Using Hierarchical Exemplar-Based Models

    OpenAIRE

    Liu, Jiongxin; Li, Yinxiao; Allen, Peter; Belhumeur, Peter

    2015-01-01

    Exemplar-based models have achieved great success on localizing the parts of semi-rigid objects. However, their efficacy on highly articulated objects such as humans is yet to be explored. Inspired by hierarchical object representation and recent application of Deep Convolutional Neural Networks (DCNNs) on human pose estimation, we propose a novel formulation that incorporates both hierarchical exemplar-based models and DCNNs in the spatial terms. Specifically, we obtain more expressive spati...

  8. Application and Realization of Hierarchical Network Planning Based on Web

    Institute of Scientific and Technical Information of China (English)

    WU Shi-jing; GONG Zhi-bo; YIN Yong; HUANG He-chao; LOU Wei-hua

    2004-01-01

    Making use of Microsoft Visual Studio.NET platform, hierarchical network planning is realized in working procedure time-optimization of the construction by TBM, and hierarchical network graph of the construction by TBM is drawn based on browser.Then the theory of system realization is discussed, six components of system that can be reused are explained emphatically.The realization of hierarchical network panning in Internet provides available guarantee for controlling rate of progress in large-scale or middle-sized projects.

  9. A Hierarchical Sensor Network Based on Voronoi Diagram

    Institute of Scientific and Technical Information of China (English)

    SHANG Rui-qiang; ZHAO Jian-li; SUN Qiu-xia; WANG Guang-xing

    2006-01-01

    A hierarchical sensor network is proposed which places the sensing and routing capacity at different layer nodes.It thus simplifies the hardware design and reduces cost. Adopting Voronoi diagram in the partition of backbone network,a mathematical model of data aggregation based on hierarchical architecture is given. Simulation shows that the number of transmission data packages is sharply cut down in the network, thus reducing the needs in the bandwidth and energy resources and is thus well adapted to sensor networks.

  10. Topology-based hierarchical scheduling using deficit round robin

    DEFF Research Database (Denmark)

    Yu, Hao; Yan, Ying; Berger, Michael Stubert

    2009-01-01

    according to the topology. The mapping process could be completed through the network management plane or by manual configuration. Based on the knowledge of the network, the scheduler can manage the traffic on behalf of other less advanced nodes, avoid potential traffic congestion, and provide flow...... protection and isolation. Comparisons between hierarchical scheduling, flow-based scheduling, and class-based scheduling schemes have been carried out under a symmetric tree topology. Results have shown that the hierarchical scheduling scheme provides better flow protection and isolation from attack of...... malicious traffic. This is significant for IPTV services in Carrier Ethernet networks....

  11. Hierarchical graphs for rule-based modeling of biochemical systems

    Directory of Open Access Journals (Sweden)

    Hu Bin

    2011-02-01

    Full Text Available Abstract Background In rule-based modeling, graphs are used to represent molecules: a colored vertex represents a component of a molecule, a vertex attribute represents the internal state of a component, and an edge represents a bond between components. Components of a molecule share the same color. Furthermore, graph-rewriting rules are used to represent molecular interactions. A rule that specifies addition (removal of an edge represents a class of association (dissociation reactions, and a rule that specifies a change of a vertex attribute represents a class of reactions that affect the internal state of a molecular component. A set of rules comprises an executable model that can be used to determine, through various means, the system-level dynamics of molecular interactions in a biochemical system. Results For purposes of model annotation, we propose the use of hierarchical graphs to represent structural relationships among components and subcomponents of molecules. We illustrate how hierarchical graphs can be used to naturally document the structural organization of the functional components and subcomponents of two proteins: the protein tyrosine kinase Lck and the T cell receptor (TCR complex. We also show that computational methods developed for regular graphs can be applied to hierarchical graphs. In particular, we describe a generalization of Nauty, a graph isomorphism and canonical labeling algorithm. The generalized version of the Nauty procedure, which we call HNauty, can be used to assign canonical labels to hierarchical graphs or more generally to graphs with multiple edge types. The difference between the Nauty and HNauty procedures is minor, but for completeness, we provide an explanation of the entire HNauty algorithm. Conclusions Hierarchical graphs provide more intuitive formal representations of proteins and other structured molecules with multiple functional components than do the regular graphs of current languages for

  12. Adaptive continuous hierarchical model-based decision making

    Czech Academy of Sciences Publication Activity Database

    Dedecius, Kamil; Ettler, P.

    Portugalsko: SciTePress – Science and Technology Publications, 2011, s. 284-289. ISBN 978-989-8425-74-4. [8th International Conference on Informatics in Control, Automation and Robotics (ICINCO). Noordwijkerhout (NL), 27.07.2011-31.07.2011] R&D Projects: GA MŠk(CZ) 7D09008; GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : Bayesian modelling * Hierarchical model * Parameter estimation Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2011/AS/dedecius-adaptive continuous hierarchical model-based decision making.pdf

  13. Hierarchical ensemble-based data fusion for structural health monitoring

    International Nuclear Information System (INIS)

    In structural health monitoring, damage detection results always have uncertainty because of three factors: measurement noise, modeling error and environment changes. Data fusion can lead to the improved accuracy of a classification decision as compared to a decision based on any individual data source alone. Ensemble approaches constitute a relatively new breed of algorithms used for data fusion. In this paper, we introduced a hierarchical ensemble scheme to the data fusion field. The hierarchical ensemble scheme was based on the Dempster–Shafer (DS) theory and the Rotation Forest (RF) method, it was called a hierarchical ensemble because the RF method itself was an ensemble method. The DS theory was used to combine the output of RF based on different data sources. The validation accuracy of the RF model was considered in the improvement of the performance of the hierarchical ensemble. Health monitoring of a small-scale two-story frame structure with different damages subject to shaking table tests was used as an example to validate the efficiency of the proposed scheme. The experimental results indicated that the proposed scheme will improve the identification accuracy and increase the reliability of identification

  14. P2MP MPLS-Based Hierarchical Service Management System

    Science.gov (United States)

    Kumaki, Kenji; Nakagawa, Ikuo; Nagami, Kenichi; Ogishi, Tomohiko; Ano, Shigehiro

    This paper proposes a point-to-multipoint (P2MP) Multi-Protocol Label Switching (MPLS) based hierarchical service management system. Traditionally, general management systems deployed in some service providers control MPLS Label Switched Paths (LSPs) (e.g., RSVP-TE and LDP) and services (e.g., L2VPN, L3VPN and IP) separately. In order for dedicated management systems for MPLS LSPs and services to cooperate with each other automatically, a hierarchical service management system has been proposed with the main focus on point-to-point (P2P) TE LSPs in MPLS path management. In the case where P2MP TE LSPs and services are deployed in MPLS networks, the dedicated management systems for P2MP TE LSPs and services must work together automatically. Therefore, this paper proposes a new algorithm that uses a correlation between P2MP TE LSPs and multicast VPN services based on a P2MP MPLS-based hierarchical service management architecture. Also, the capacity and performance of the proposed algorithm are evaluated by simulations, which are actually based on certain real MPLS production networks, and are compared to that of the algorithm for P2P TE LSPs. Results show this system is very scalable within real MPLS production networks. This system, with the automatic correlation, appears to be deployable in real MPLS production networks.

  15. Agent-based distributed hierarchical control of dc microgrid systems

    DEFF Research Database (Denmark)

    Meng, Lexuan; Vasquez, Juan Carlos; Guerrero, Josep M.;

    2014-01-01

    In order to enable distributed control and management for microgrids, this paper explores the application of information consensus and local decisionmaking methods formulating an agent based distributed hierarchical control system. A droop controlled paralleled DC/DC converter system is taken as ....... Standard genetic algorithm is applied in each local control system in order to search for a global optimum. Hardware-in-Loop simulation results are shown to demonstrate the effectiveness of the method....

  16. Room Categorization Based on a Hierarchical Representation of Space

    OpenAIRE

    Peter Uršič; Domen Tabernik; Marko Boben; Danijel Skočaj; Aleš Leonardis; Matej Kristan

    2013-01-01

    For successful operation in real‐world environments, a mobile robot requires an effective spatial model. The model should be compact, should possess large expressive power and should scale well with respect to the number of modelled categories. In this paper we propose a new compositional hierarchical representation of space that is based on learning statistically significant observations, in terms of the frequency of occurrence of various shapes in the environment. We have focused on a two‐d...

  17. Multimodal Hierarchical Dirichlet Process-based Active Perception

    OpenAIRE

    Taniguchi, Tadahiro; Takano, Toshiaki; Yoshino, Ryo

    2015-01-01

    In this paper, we propose an active perception method for recognizing object categories based on the multimodal hierarchical Dirichlet process (MHDP). The MHDP enables a robot to form object categories using multimodal information, e.g., visual, auditory, and haptic information, which can be observed by performing actions on an object. However, performing many actions on a target object requires a long time. In a real-time scenario, i.e., when the time is limited, the robot has to determine t...

  18. Image Hierarchical Representations Models based on Latent Dirichlet Allocation

    Directory of Open Access Journals (Sweden)

    Fushun WANG

    2013-08-01

    Full Text Available Existing image layer representations methods are very feed-forward, and then not able to deal with small ambiguities. A probabilistic model is proposed, and it learns and deduces each layer in that hierarchy together. Therefore, we consider a recursive probabilistic decomposition process, and derive a new yielded method based on recursive Latent Dirichlet Allocation. We show 2 significant properties of the novel probabilistic method: 1 pulsing another hierarchical to represent the enhanced results on that smooth method; 2 an entire Bayesian method beats a feed-forward running of the novel method. The method can be evaluated on a criterion recognition dataset. It takes the probability of recursive decomposition process into account, and obtains multilayer structure pyramid LDA derived model through the derivation. Experiments demonstrate that the novel technique beats existing hierarchical approaches, and present better performance

  19. Robust Pedestrian Classification Based on Hierarchical Kernel Sparse Representation.

    Science.gov (United States)

    Sun, Rui; Zhang, Guanghai; Yan, Xiaoxing; Gao, Jun

    2016-01-01

    Vision-based pedestrian detection has become an active topic in computer vision and autonomous vehicles. It aims at detecting pedestrians appearing ahead of the vehicle using a camera so that autonomous vehicles can assess the danger and take action. Due to varied illumination and appearance, complex background and occlusion pedestrian detection in outdoor environments is a difficult problem. In this paper, we propose a novel hierarchical feature extraction and weighted kernel sparse representation model for pedestrian classification. Initially, hierarchical feature extraction based on a CENTRIST descriptor is used to capture discriminative structures. A max pooling operation is used to enhance the invariance of varying appearance. Then, a kernel sparse representation model is proposed to fully exploit the discrimination information embedded in the hierarchical local features, and a Gaussian weight function as the measure to effectively handle the occlusion in pedestrian images. Extensive experiments are conducted on benchmark databases, including INRIA, Daimler, an artificially generated dataset and a real occluded dataset, demonstrating the more robust performance of the proposed method compared to state-of-the-art pedestrian classification methods. PMID:27537888

  20. A VV&A evaluation system based on hierarchical evaluation

    Institute of Scientific and Technical Information of China (English)

    FANG Ke; YANG Ming; WANG Zi-cai

    2005-01-01

    Evaluation is the major activity of performing Verification, Validation and Accreditation (VV&A) of a simulation system. Unfortunately, there is a lack of reasonable and operable evaluation methods. Moreover,there are other problems to address in VV&A evaluation, such as index definition, conclusion analysis, etc. In this paper, a VV&A evaluation system is introduced to try to resolve these problems. The system is based on a method called hierarchical evaluation, and it uses a good combination of evaluation processes and indexes.First, a thorough analysis of the VV&A evaluation' s essentials and principles are given, then the uncertainty of the evaluation results caused by various analysis of the evaluators is pointed out, then a hierarchical evaluation mechanism based on evaluator weight and evaluation hierarchy is brought forward, and finally a comprehensive VV&A evaluation system with evaluation flow processing, index management and hierarchical evaluation fulfillment is established. The system gives good consideration to ease of operation, reasonableness of evaluation conclusion, and the ability to comprehensively resolve VV&A problems. Since VV&A is attracting more and more recognition, it is meaningful to provide a good system for implementing credible simulation systems. It is hoped that this VV&A evaluation will provide a good way.

  1. Hierarchical control based on Hopfield network for nonseparable optimization problems

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The nonseparable optimization control problem is considered, where the overall objective function is not of an additive form with respect to subsystems. Since there exists the problem that computation is very slow when using iterative algorithms in multiobjective optimization, Hopfield optimization hierarchical network based on IPM is presented to overcome such slow computation difficulty. Asymptotic stability of this Hopfield network is proved and its equilibrium point is the optimal point of the original problem. The simulation shows that the net is effective to deal with the optimization control problem for large-scale nonseparable steady state systems.

  2. 3D automatic anatomy segmentation based on iterative graph-cut-ASM

    OpenAIRE

    Chen, Xinjian; Bagci, Ulas

    2011-01-01

    Purpose: This paper studies the feasibility of developing an automatic anatomy segmentation (AAS) system in clinical radiology and demonstrates its operation on clinical 3D images.Methods: The AAS system, the authors are developing consists of two main parts: object recognition and object delineation. As for recognition, a hierarchical 3D scale-based multiobject method is used for the multiobject recognition task, which incorporates intensity weighted ball-scale (b-scale) information into the...

  3. Efficiently dense hierarchical graphene based aerogel electrode for supercapacitors

    Science.gov (United States)

    Wang, Xin; Lu, Chengxing; Peng, Huifen; Zhang, Xin; Wang, Zhenkun; Wang, Gongkai

    2016-08-01

    Boosting gravimetric and volumetric capacitances simultaneously at a high rate is still a discrepancy in development of graphene based supercapacitors. We report the preparation of dense hierarchical graphene/activated carbon composite aerogels via a reduction induced self-assembly process coupled with a drying post treatment. The compact and porous structures of composite aerogels could be maintained. The drying post treatment has significant effects on increasing the packing density of aerogels. The introduced activated carbons play the key roles of spacers and bridges, mitigating the restacking of adjacent graphene nanosheets and connecting lateral and vertical graphene nanosheets, respectively. The optimized aerogel with a packing density of 0.67 g cm-3 could deliver maximum gravimetric and volumetric capacitances of 128.2 F g-1 and 85.9 F cm-3, respectively, at a current density of 1 A g-1 in aqueous electrolyte, showing no apparent degradation to the specific capacitance at a current density of 10 A g-1 after 20000 cycles. The corresponding gravimetric and volumetric capacitances of 116.6 F g-1 and 78.1 cm-3 with an acceptable cyclic stability are also achieved in ionic liquid electrolyte. The results show a feasible strategy of designing dense hierarchical graphene based aerogels for supercapacitors.

  4. Facial animation on an anatomy-based hierarchical face model

    Science.gov (United States)

    Zhang, Yu; Prakash, Edmond C.; Sung, Eric

    2003-04-01

    In this paper we propose a new hierarchical 3D facial model based on anatomical knowledge that provides high fidelity for realistic facial expression animation. Like real human face, the facial model has a hierarchical biomechanical structure, incorporating a physically-based approximation to facial skin tissue, a set of anatomically-motivated facial muscle actuators and underlying skull structure. The deformable skin model has multi-layer structure to approximate different types of soft tissue. It takes into account the nonlinear stress-strain relationship of the skin and the fact that soft tissue is almost incompressible. Different types of muscle models have been developed to simulate distribution of the muscle force on the skin due to muscle contraction. By the presence of the skull model, our facial model takes advantage of both more accurate facial deformation and the consideration of facial anatomy during the interactive definition of facial muscles. Under the muscular force, the deformation of the facial skin is evaluated using numerical integration of the governing dynamic equations. The dynamic facial animation algorithm runs at interactive rate with flexible and realistic facial expressions to be generated.

  5. Hand Tracking based on Hierarchical Clustering of Range Data

    CERN Document Server

    Cespi, Roberto; Lindner, Marvin

    2011-01-01

    Fast and robust hand segmentation and tracking is an essential basis for gesture recognition and thus an important component for contact-less human-computer interaction (HCI). Hand gesture recognition based on 2D video data has been intensively investigated. However, in practical scenarios purely intensity based approaches suffer from uncontrollable environmental conditions like cluttered background colors. In this paper we present a real-time hand segmentation and tracking algorithm using Time-of-Flight (ToF) range cameras and intensity data. The intensity and range information is fused into one pixel value, representing its combined intensity-depth homogeneity. The scene is hierarchically clustered using a GPU based parallel merging algorithm, allowing a robust identification of both hands even for inhomogeneous backgrounds. After the detection, both hands are tracked on the CPU. Our tracking algorithm can cope with the situation that one hand is temporarily covered by the other hand.

  6. DNA sequence analysis using hierarchical ART-based classification networks

    Energy Technology Data Exchange (ETDEWEB)

    LeBlanc, C.; Hruska, S.I. [Florida State Univ., Tallahassee, FL (United States); Katholi, C.R.; Unnasch, T.R. [Univ. of Alabama, Birmingham, AL (United States)

    1994-12-31

    Adaptive resonance theory (ART) describes a class of artificial neural network architectures that act as classification tools which self-organize, work in real-time, and require no retraining to classify novel sequences. We have adapted ART networks to provide support to scientists attempting to categorize tandem repeat DNA fragments from Onchocerca volvulus. In this approach, sequences of DNA fragments are presented to multiple ART-based networks which are linked together into two (or more) tiers; the first provides coarse sequence classification while the sub- sequent tiers refine the classifications as needed. The overall rating of the resulting classification of fragments is measured using statistical techniques based on those introduced to validate results from traditional phylogenetic analysis. Tests of the Hierarchical ART-based Classification Network, or HABclass network, indicate its value as a fast, easy-to-use classification tool which adapts to new data without retraining on previously classified data.

  7. Hierarchical message bus-based software architectural style

    Institute of Scientific and Technical Information of China (English)

    张世琨; 王立福; 杨芙清

    2002-01-01

    As the size and complexity of software systems increase,the design and specification of overall system structure become more significant issues than the choice of algorithms and data structures of computation.An appropriate architecture for a system is a key element of its success.Based on the practice of Jadebird software production line,this paper proposes a software architectural style based on hierarchical message buses,named JB/HMB.In this style,the component model consists of external interfaces,static structure and dynamic behavior,which depicts a component from different aspects.Supported by message buses,components interact with one another by messages,which can be used to describe distributed and concurrent systems well.JB/HMB style supports stepwise decomposition and refinement,and runtime system evolution.Finally,characteristics of JB/HMB style are summarized as a conclusion,and future research directions are specified.``

  8. Investment portfolio risk modelling based on hierarchical copulas

    OpenAIRE

    Penikas, Henry

    2014-01-01

    Paper is devoted to comparison of various copula models application to investment portfolio risk measurement. Elliptical, Archimedean and hierarchical copulas are considered in the research. The analysis undertaken has shown that hierarchical Clayton model enables to evaluate investment portfolio risks more precisely given the criteria of risk measures such as expected shortfall (ES) and Value-at-Risk (VaR). Statistically justified approach to hierarchical copula definition is also proposed.

  9. A Model of Knowledge Based Information Retrieval with Hierarchical Concept Graph.

    Science.gov (United States)

    Kim, Young Whan; Kim, Jin H.

    1990-01-01

    Proposes a model of knowledge-based information retrieval (KBIR) that is based on a hierarchical concept graph (HCG) which shows relationships between index terms and constitutes a hierarchical thesaurus as a knowledge base. Conceptual distance between a query and an object is discussed and the use of Boolean operators is described. (25…

  10. Chromatin structure analysis based on a hierarchic texture model.

    Science.gov (United States)

    Wolf, G; Beil, M; Guski, H

    1995-02-01

    The quantification of chromatin structures is an important part of nuclear grading of malignant and premalignant lesions. In order to achieve high accuracy, computerized image analysis systems have been applied in this process. Chromatin texture analysis of cell nuclei requires a suitable texture model. A hierarchic model seemed to be most compatible for this purpose. It assumes that texture consists of homogeneous regions (textons). Based on this model, two approaches to texture segmentation and feature extraction were investigated using sections of cervical tissue. We examined the reproducibility of the measurement under changing optical conditions. The coefficients of variations of the texture features ranged from 2.1% to 16.9%. The features were tested for their discriminating capability in a pilot study including 30 cases of cervical dysplasia and carcinoma. The overall classification accuracy reached 65%. This study presents an automated technique for texture analysis that is similar to human perception. PMID:7766266

  11. Hierarchical cobalt-based hydroxide microspheres for water oxidation

    Science.gov (United States)

    Zhang, Ye; Cui, Bai; Derr, Olivia; Yao, Zhibo; Qin, Zhaotong; Deng, Xiangyun; Li, Jianbao; Lin, Hong

    2014-02-01

    3D hierarchical cobalt hydroxide carbonate hydrate (Co(CO3)0.5(OH).0.11H2O) has been synthesized featuring a hollow urchin-like structure by a one-step hydrothermal method at modest temperature on FTO glass substrates. The functionalities of precursor surfactants were isolated and analyzed. A plausible formation mechanism of the spherical urchin-like microclusters has been furnished through time-dependent investigations. Introduction of other transitional metal doping (Cu, Ni) would give rise to a substantial morphological change associated with a surface area drop. The directly grown cobalt-based hydroxide composite electrodes were found to be capable of catalyzing oxygen evolution reaction (OER) under both neutral pH and alkaline conditions. The favorable 3D dendritic morphology and porous structure provide large surface areas and possible defect sites that are likely responsible for their robust electrochemical activity.

  12. Global Crop Monitoring: A Satellite-Based Hierarchical Approach

    Directory of Open Access Journals (Sweden)

    Bingfang Wu

    2015-04-01

    Full Text Available Taking advantage of multiple new remote sensing data sources, especially from Chinese satellites, the CropWatch system has expanded the scope of its international analyses through the development of new indicators and an upgraded operational methodology. The approach adopts a hierarchical system covering four spatial levels of detail: global, regional, national (thirty-one key countries including China and “sub-countries” (for the nine largest countries. The thirty-one countries encompass more that 80% of both production and exports of maize, rice, soybean and wheat. The methodology resorts to climatic and remote sensing indicators at different scales. The global patterns of crop environmental growing conditions are first analyzed with indicators for rainfall, temperature, photosynthetically active radiation (PAR as well as potential biomass. At the regional scale, the indicators pay more attention to crops and include Vegetation Health Index (VHI, Vegetation Condition Index (VCI, Cropped Arable Land Fraction (CALF as well as Cropping Intensity (CI. Together, they characterize crop situation, farming intensity and stress. CropWatch carries out detailed crop condition analyses at the national scale with a comprehensive array of variables and indicators. The Normalized Difference Vegetation Index (NDVI, cropped areas and crop conditions are integrated to derive food production estimates. For the nine largest countries, CropWatch zooms into the sub-national units to acquire detailed information on crop condition and production by including new indicators (e.g., Crop type proportion. Based on trend analysis, CropWatch also issues crop production supply outlooks, covering both long-term variations and short-term dynamic changes in key food exporters and importers. The hierarchical approach adopted by CropWatch is the basis of the analyses of climatic and crop conditions assessments published in the quarterly “CropWatch bulletin” which

  13. Hierarchical Real-time Network Traffic Classification Based on ECOC

    Directory of Open Access Journals (Sweden)

    Yaou Zhao

    2013-09-01

    Full Text Available Classification of network traffic is basic and essential for manynetwork researches and managements. With the rapid development ofpeer-to-peer (P2P application using dynamic port disguisingtechniques and encryption to avoid detection, port-based and simplepayload-based network traffic classification methods were diminished.An alternative method based on statistics and machine learning hadattracted researchers' attention in recent years. However, most ofthe proposed algorithms were off-line and usually used a single classifier.In this paper a new hierarchical real-time model was proposed which comprised of a three tuple (source ip, destination ip and destination portlook up table(TT-LUT part and layered milestone part. TT-LUT was used to quickly classify short flows whichneed not to pass the layered milestone part, and milestones in layered milestone partcould classify the other flows in real-time with the real-time feature selection and statistics.Every milestone was a ECOC(Error-Correcting Output Codes based model which was usedto improve classification performance. Experiments showed that the proposedmodel can improve the efficiency of real-time to 80%, and themulti-class classification accuracy encouragingly to 91.4% on the datasets which had been captured from the backbone router in our campus through a week.

  14. Hierarchical structure analysis describing abnormal base composition of genomes

    Science.gov (United States)

    Ouyang, Zhengqing; Liu, Jian-Kun; She, Zhen-Su

    2005-10-01

    Abnormal base compositional patterns of genomic DNA sequences are studied in the framework of a hierarchical structure (HS) model originally proposed for the study of fully developed turbulence [She and Lévêque, Phys. Rev. Lett. 72, 336 (1994)]. The HS similarity law is verified over scales between 103bp and 105bp , and the HS parameter β is proposed to describe the degree of heterogeneity in the base composition patterns. More than one hundred bacteria, archaea, virus, yeast, and human genome sequences have been analyzed and the results show that the HS analysis efficiently captures abnormal base composition patterns, and the parameter β is a characteristic measure of the genome. Detailed examination of the values of β reveals an intriguing link to the evolutionary events of genetic material transfer. Finally, a sequence complexity (S) measure is proposed to characterize gradual increase of organizational complexity of the genome during the evolution. The present study raises several interesting issues in the evolutionary history of genomes.

  15. A Bayesian, exemplar-based approach to hierarchical shape matching.

    Science.gov (United States)

    Gavrila, Dariu M

    2007-08-01

    This paper presents a novel probabilistic approach to hierarchical, exemplar-based shape matching. No feature correspondence is needed among exemplars, just a suitable pairwise similarity measure. The approach uses a template tree to efficiently represent and match the variety of shape exemplars. The tree is generated offline by a bottom-up clustering approach using stochastic optimization. Online matching involves a simultaneous coarse-to-fine approach over the template tree and over the transformation parameters. The main contribution of this paper is a Bayesian model to estimate the a posteriori probability of the object class, after a certain match at a node of the tree. This model takes into account object scale and saliency and allows for a principled setting of the matching thresholds such that unpromising paths in the tree traversal process are eliminated early on. The proposed approach was tested in a variety of application domains. Here, results are presented on one of the more challenging domains: real-time pedestrian detection from a moving vehicle. A significant speed-up is obtained when comparing the proposed probabilistic matching approach with a manually tuned nonprobabilistic variant, both utilizing the same template tree structure. PMID:17568144

  16. Iris Image Classification Based on Hierarchical Visual Codebook.

    Science.gov (United States)

    Zhenan Sun; Hui Zhang; Tieniu Tan; Jianyu Wang

    2014-06-01

    Iris recognition as a reliable method for personal identification has been well-studied with the objective to assign the class label of each iris image to a unique subject. In contrast, iris image classification aims to classify an iris image to an application specific category, e.g., iris liveness detection (classification of genuine and fake iris images), race classification (e.g., classification of iris images of Asian and non-Asian subjects), coarse-to-fine iris identification (classification of all iris images in the central database into multiple categories). This paper proposes a general framework for iris image classification based on texture analysis. A novel texture pattern representation method called Hierarchical Visual Codebook (HVC) is proposed to encode the texture primitives of iris images. The proposed HVC method is an integration of two existing Bag-of-Words models, namely Vocabulary Tree (VT), and Locality-constrained Linear Coding (LLC). The HVC adopts a coarse-to-fine visual coding strategy and takes advantages of both VT and LLC for accurate and sparse representation of iris texture. Extensive experimental results demonstrate that the proposed iris image classification method achieves state-of-the-art performance for iris liveness detection, race classification, and coarse-to-fine iris identification. A comprehensive fake iris image database simulating four types of iris spoof attacks is developed as the benchmark for research of iris liveness detection. PMID:26353275

  17. Quick Web Services Lookup Model Based on Hierarchical Registration

    Institute of Scientific and Technical Information of China (English)

    谢山; 朱国进; 陈家训

    2003-01-01

    Quick Web Services Lookup (Q-WSL) is a new model to registration and lookup of complex services in the Internet. The model is designed to quickly find complex Web services by using hierarchical registration method. The basic concepts of Web services system are introduced and presented, and then the method of hierarchical registration of services is described. In particular, service query document description and service lookup procedure are concentrated, and it addresses how to lookup these services which are registered in the Web services system. Furthermore, an example design and an evaluation of its performance are presented.Specifically, it shows that the using of attributionbased service query document design and contentbased hierarchical registration in Q-WSL allows service requesters to discover needed services more flexibly and rapidly. It is confirmed that Q-WSL is very suitable for Web services system.

  18. Hierarchical Scheduling Framework Based on Compositional Analysis Using Uppaal

    DEFF Research Database (Denmark)

    Boudjadar, Jalil; David, Alexandre; Kim, Jin Hyun;

    2014-01-01

    This paper introduces a reconfigurable compositional scheduling framework, in which the hierarchical structure, the scheduling policies, the concrete task behavior and the shared resources can all be reconfigured. The behavior of each periodic preemptive task is given as a list of timed actions, ...

  19. Priority-Based Hierarchical Operational Management for Multiagent-Based Microgrids

    Directory of Open Access Journals (Sweden)

    Takumi Kato

    2014-03-01

    Full Text Available Electricity consumption in the world is constantly increasing, making our lives become more and more dependent on electricity. There are several new paradigms proposed in the field of power grids. In Japan, especially after the Great East Japan Earthquake in March 2011, the new power grid paradigms are expected to be more resilient to survive several difficulties during disasters. In this paper, we focus on microgrids and propose priority-based hierarchical operational management for multiagent-based microgrids. The proposed management is a new multiagent-based load shedding scheme and multiagent-based hierarchical architecture to realize such resilient microgrids. We developed a prototype system and performed an evaluation of the proposed management using the developed system. The result of the evaluation shows the effectiveness of our proposal in power shortage situations, such as disasters.

  20. ANALYTICAL HIERARCHICAL PROCESS BASED SYSTEM FOR IMAGE FUSION

    OpenAIRE

    Ashok Kumar; Amruta Shelar; Jim Etheredge; Sandhya Prakash; Sudhansh Sharma; MP Mishra

    2015-01-01

    Image fusion has been rapidly gaining importance in application areas such as medical imaging, remote sensing, robotics, navigation and the military. This has led to emergence of several algorithms for image fusion for generating more precise images. This paper presents a novel approach of selecting best image fusion algorithm for a given scenario using Analytical Hierarchical Process (AHP) involving eigen vectors. Evaluations of the proposed approach indicate higher quality of fu...

  1. ANALYTICAL HIERARCHICAL PROCESS BASED SYSTEM FOR IMAGE FUSION

    Directory of Open Access Journals (Sweden)

    Ashok Kumar

    2015-10-01

    Full Text Available Image fusion has been rapidly gaining importance in application areas such as medical imaging, remote sensing, robotics, navigation and the military. This has led to emergence of several algorithms for image fusion for generating more precise images. This paper presents a novel approach of selecting best image fusion algorithm for a given scenario using Analytical Hierarchical Process (AHP involving eigen vectors. Evaluations of the proposed approach indicate higher quality of fused images.

  2. Hierarchical, model-based risk management of critical infrastructures

    Energy Technology Data Exchange (ETDEWEB)

    Baiardi, F. [Polo G.Marconi La Spezia, Universita di Pisa, Pisa (Italy); Dipartimento di Informatica, Universita di Pisa, L.go B.Pontecorvo 3 56127, Pisa (Italy)], E-mail: f.baiardi@unipi.it; Telmon, C.; Sgandurra, D. [Dipartimento di Informatica, Universita di Pisa, L.go B.Pontecorvo 3 56127, Pisa (Italy)

    2009-09-15

    Risk management is a process that includes several steps, from vulnerability analysis to the formulation of a risk mitigation plan that selects countermeasures to be adopted. With reference to an information infrastructure, we present a risk management strategy that considers a sequence of hierarchical models, each describing dependencies among infrastructure components. A dependency exists anytime a security-related attribute of a component depends upon the attributes of other components. We discuss how this notion supports the formal definition of risk mitigation plan and the evaluation of the infrastructure robustness. A hierarchical relation exists among models that are analyzed because each model increases the level of details of some components in a previous one. Since components and dependencies are modeled through a hypergraph, to increase the model detail level, some hypergraph nodes are replaced by more and more detailed hypergraphs. We show how critical information for the assessment can be automatically deduced from the hypergraph and define conditions that determine cases where a hierarchical decomposition simplifies the assessment. In these cases, the assessment has to analyze the hypergraph that replaces the component rather than applying again all the analyses to a more detailed, and hence larger, hypergraph. We also show how the proposed framework supports the definition of a risk mitigation plan and discuss some indicators of the overall infrastructure robustness. Lastly, the development of tools to support the assessment is discussed.

  3. Structural Group-based Auditing of Missing Hierarchical Relationships in UMLS

    Science.gov (United States)

    Chen, Yan; Gu, Huanying(Helen); Perl, Yehoshua; Geller, James

    2009-01-01

    The Metathesaurus of the UMLS was created by integrating various source terminologies. The inter-concept relationships were either integrated into the UMLS from the source terminologies or specially generated. Due to the extensive size and inherent complexity of the Metathesaurus, the accidental omission of some hierarchical relationships was inevitable. We present a recursive procedure which allows a human expert, with the support of an algorithm, to locate missing hierarchical relationships. The procedure starts with a group of concepts with exactly the same (correct) semantic type assignments. It then partitions the concepts, based on child-of hierarchical relationships, into smaller, singly rooted, hierarchically connected subgroups. The auditor only needs to focus on the subgroups with very few concepts and their concepts with semantic type reassignments. The procedure was evaluated by comparing it with a comprehensive manual audit and it exhibits a perfect error recall. PMID:18824248

  4. Multi- Layer Tree Hierarchical Architecture Based on Web Service

    Institute of Scientific and Technical Information of China (English)

    TONG Hengjian; LI Deren; ZHU Xinyan; SHAO Zhenfeng

    2006-01-01

    To solve the problem of the information share and services integration in population information system, we propose a multi-layer tree hierarchical architecture. The com mand (Web Service Call) is recursively multicast from top layer of tree to bottom layer of tree and statistical data are gathered from bottom layer to top layer. We implemented the architecture by using Web Services technology. In our implementation, client program is the requestor of Web Services,and all leaf nodes of the last layer are only the provider of Web Services. For those nodes of intermediate layers, every node is not only the provider of Web Services, but also the dispatcher of Web Services. We take population census as an example to describe the working flow of the architecture.

  5. IPTV traffic management using topology-based hierarchical scheduling in Carrier Ethernet transport networks

    DEFF Research Database (Denmark)

    Yu, Hao; Yan, Ying; Berger, Michael Stubert

    2009-01-01

    Service (QoS) provisioning abilities, which guarantee end-to-end performances of voice, video and data traffic delivered over networks. This paper introduces a topology-based hierarchical scheduler scheme, which controls the incoming traffic at the edge of the network based on the network topology. This...

  6. Marker-Based Hierarchical Segmentation and Classification Approach for Hyperspectral Imagery

    Science.gov (United States)

    Tarabalka, Yuliya; Tilton, James C.; Benediktsson, Jon Atli; Chanussot, Jocelyn

    2011-01-01

    The Hierarchical SEGmentation (HSEG) algorithm, which is a combination of hierarchical step-wise optimization and spectral clustering, has given good performances for hyperspectral image analysis. This technique produces at its output a hierarchical set of image segmentations. The automated selection of a single segmentation level is often necessary. We propose and investigate the use of automatically selected markers for this purpose. In this paper, a novel Marker-based HSEG (M-HSEG) method for spectral-spatial classification of hyperspectral images is proposed. First, pixelwise classification is performed and the most reliably classified pixels are selected as markers, with the corresponding class labels. Then, a novel constrained marker-based HSEG algorithm is applied, resulting in a spectral-spatial classification map. The experimental results show that the proposed approach yields accurate segmentation and classification maps, and thus is attractive for hyperspectral image analysis.

  7. Future Unified Communication Based on Ubiquitous Hierarchical Generalized-Sensor Network Architecture

    Directory of Open Access Journals (Sweden)

    Zhitong Huang

    2012-03-01

    Full Text Available Recent advances in wireless sensor network (WSN and radio frequency identifier (RFID have made it possible to extend current human-to-human communication to the future unified communication environment among human society, computer network and the external physical world. A ubiquitous hierarchical generalized-sensor network (UHGSN is presented in this paper as a typical network model for such unified communication architecture. The sensor information processing unit and the hierarchical distributed agent server are introduced as the basic network elements in this architecture for effective information communication, and the topology, addressing and recovery problems are analyzed. As the basic applications, the combined “key word” based characterized searching mechanism and the performance monitoring processes are discussed, along with the corresponding protocol message definition and encoding format. Simulation results show the advancements of the presented hierarchical architecture and the job-list based characterized searching mechanism.

  8. A Biological Hierarchical Model Based Underwater Moving Object Detection

    Directory of Open Access Journals (Sweden)

    Jie Shen

    2014-01-01

    Full Text Available Underwater moving object detection is the key for many underwater computer vision tasks, such as object recognizing, locating, and tracking. Considering the super ability in visual sensing of the underwater habitats, the visual mechanism of aquatic animals is generally regarded as the cue for establishing bionic models which are more adaptive to the underwater environments. However, the low accuracy rate and the absence of the prior knowledge learning limit their adaptation in underwater applications. Aiming to solve the problems originated from the inhomogeneous lumination and the unstable background, the mechanism of the visual information sensing and processing pattern from the eye of frogs are imitated to produce a hierarchical background model for detecting underwater objects. Firstly, the image is segmented into several subblocks. The intensity information is extracted for establishing background model which could roughly identify the object and the background regions. The texture feature of each pixel in the rough object region is further analyzed to generate the object contour precisely. Experimental results demonstrate that the proposed method gives a better performance. Compared to the traditional Gaussian background model, the completeness of the object detection is 97.92% with only 0.94% of the background region that is included in the detection results.

  9. A Framework for Hierarchical Clustering Based Indexing in Search Engines

    Directory of Open Access Journals (Sweden)

    Parul Gupta

    2011-01-01

    Full Text Available Granting efficient and fast accesses to the index is a key issuefor performances of Web Search Engines. In order to enhancememory utilization and favor fast query resolution, WSEs useInverted File (IF indexes that consist of an array of theposting lists where each posting list is associated with a termand contains the term as well as the identifiers of the documentscontaining the term. Since the document identifiers are stored insorted order, they can be stored as the difference between thesuccessive documents so as to reduce the size of the index. Thispaper describes a clustering algorithm that aims atpartitioning the set of documents into ordered clusters so thatthe documents within the same cluster are similar and are beingassigned the closer document identifiers. Thus the averagevalue of the differences between the successive documents willbe minimized and hence storage space would be saved. Thepaper further presents the extension of this clustering algorithmto be applied for the hierarchical clustering in which similarclusters are clubbed to form a mega cluster and similar megaclusters are then combined to form super cluster. Thus thepaper describes the different levels of clustering whichoptimizes the search process by directing the searchto a specific path from higher levels of clustering to the lowerlevels i.e. from super clusters to mega clusters, then to clustersand finally to the individual documents so that the user gets thebest possible matching results in minimum possible time.

  10. A biological hierarchical model based underwater moving object detection.

    Science.gov (United States)

    Shen, Jie; Fan, Tanghuai; Tang, Min; Zhang, Qian; Sun, Zhen; Huang, Fengchen

    2014-01-01

    Underwater moving object detection is the key for many underwater computer vision tasks, such as object recognizing, locating, and tracking. Considering the super ability in visual sensing of the underwater habitats, the visual mechanism of aquatic animals is generally regarded as the cue for establishing bionic models which are more adaptive to the underwater environments. However, the low accuracy rate and the absence of the prior knowledge learning limit their adaptation in underwater applications. Aiming to solve the problems originated from the inhomogeneous lumination and the unstable background, the mechanism of the visual information sensing and processing pattern from the eye of frogs are imitated to produce a hierarchical background model for detecting underwater objects. Firstly, the image is segmented into several subblocks. The intensity information is extracted for establishing background model which could roughly identify the object and the background regions. The texture feature of each pixel in the rough object region is further analyzed to generate the object contour precisely. Experimental results demonstrate that the proposed method gives a better performance. Compared to the traditional Gaussian background model, the completeness of the object detection is 97.92% with only 0.94% of the background region that is included in the detection results. PMID:25140194

  11. A hierarchic approach based on swarm intelligence to solve the traveling salesman problem

    OpenAIRE

    Gündüz, Mesut; KIRAN, Mustafa Servet; ÖZCEYLAN, Eren

    2015-01-01

    The purpose of this paper is to present a new hierarchic method based on swarm intelligence algorithms for solving the well-known traveling salesman problem. The swarm intelligence algorithms implemented in this study are divided into 2 types: path construction-based and path improvement-based methods. The path construction-based method (ant colony optimization (ACO)) produces good solutions but takes more time to achieve a good solution, while the path improvement-based technique (artificial...

  12. An Approach to Assembly Sequence Plannning Based on Hierarchical Strategy and Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    Niu Xinwen; Ding Han; Xiong Youlun

    2001-01-01

    Using group and subassembly cluster methods, the hierarchical structure of a product is.generated automatically, which largely reduces the complexity of planning. Based on genetic algofithn the optimal of assembly sequence of each stracture level can be obtained by sequence-bysequence search. As a result, a better assembly sequence of the product can be generated by combining the assembly sequences of all hierarchical structures, which provides more parallelism and flexibility for assembly operations. An industrial example is solved by this new approach.

  13. Hierarchical Pore Development by Plasma Etching of Zr-Based Metal-Organic Frameworks.

    Science.gov (United States)

    DeCoste, Jared B; Rossin, Joseph A; Peterson, Gregory W

    2015-12-01

    The typically stable Zr-based metal-organic frameworks (MOFs) UiO-66 and UiO-66-NH2 were treated with tetrafluoromethane (CF4 ) and hexafluoroethane (C2 F6 ) plasmas. Through interactions between fluoride radicals from the perfluoroalkane plasma and the zirconium-oxygen bonds of the MOF, the resulting materials showed the development of mesoporosity, creating a hierarchical pore structure. It is anticipated that this strategy can be used as a post-synthetic technique for developing hierarchical networks in a variety of MOFs. PMID:26443007

  14. Engineering hierarchical complex systems: an agent-based approach. The case of flexible manufacturing systems

    CERN Document Server

    Morvan, Gildas; Soyez, Jean-Baptiste; Merzouki, Rochdi; 10.1007/978-3-642-27449-7_4

    2012-01-01

    This article introduces a formal model to specify, model and validate hierarchical complex systems described at different levels of analysis. It relies on concepts that have been developed in the multi-agent-based simulation (MABS) literature: level, influence and reaction. One application of such model is the specification of hierarchical complex systems, in which decisional capacities are dynamically adapted at each level with respect to the emergences/constraints paradigm. In the conclusion, we discuss the main perspective of this work: the definition of a generic meta-model for holonic multi-agent systems (HMAS).

  15. A Hierarchical Control Architecture for a PEBB-Based ILC Marx Modulator

    International Nuclear Information System (INIS)

    The idea of building power conversion systems around Power Electronic Building Blocks (PEBBs) was initiated by the U.S. Office of Naval Research in the mid 1990s. A PEBB-based design approach is advantageous in terms of power density, modularity, reliability, and serviceability. It is obvious that this approach has much appeal for pulsed power conversion including the International Linear Collider (ILC) klystron modulator application. A hierarchical control architecture has the inherent capability to support the integration of PEBBs. This has already been successfully demonstrated in a number of industrial applications in the recent past. This paper outlines the underlying concepts of a hierarchical control architecture for a PEBB-based Marx-topology ILC klystron modulator. The control in PEBB-based power conversion systems can be functionally partitioned into (three) hierarchical layers; system layer, application layer, and PEBB layer. This has been adopted here. Based on such a hierarchical partition, the interfaces are clearly identified and defined and, consequently, are easily characterised. A conceptual design of the hardware manager, executing low-level hardware oriented tasks, is detailed. In addition, the idea of prognostics is briefly discussed.

  16. Iris Recognition Using Modified Hierarchical Phase-Based Matching (HPM) Technique

    OpenAIRE

    C.Anand Deva Durai; M.Karnan

    2010-01-01

    This paper explores an efficient algorithm for iris recognition based on Hierarchical Phase-Based Image Matching (HPM) technique. One of the difficult problems in feature-based iris recognition is that the matching performance is significantly influenced by many parameters in feature extraction process, which may vary depending on environmental factors of image acquisition. The proposed system is designed for applications where the training database contains an iris for each individual. The f...

  17. Content Based Image Retrieval using Hierarchical and K-Means Clustering Techniques

    OpenAIRE

    V.S.V.S. Murthy; E.Vamsidhar; J.N.V.R SWARUP KUMAR; P.Sankara Rao

    2010-01-01

    In this paper we present an image retrieval system that takes an image as the input query and retrieves images based on image content. Content Based Image Retrieval is an approach for retrieving semantically-relevant images from an image database based on automatically-derived image features. The unique aspect of the system is the utilization of hierarchical and k-means clustering techniques. The proposed procedure consists of two stages. First, here we are going to filter most of the images ...

  18. Construction of Neural Networks that Do Not Have Critical Points Based on Hierarchical Structure

    Directory of Open Access Journals (Sweden)

    Tohru Nitta

    2013-10-01

    Full Text Available a critical point is a point at which the derivatives of an error function are all zero. It has been shown in the literature that critical points caused by the hierarchical structure of a real-valued neural network (NN can be local minima or saddle points, although most critical points caused by the hierarchical structure are saddle points in the case of complex-valued neural networks. Several studies have demonstrated that singularity of those kinds has a negative effect on learning dynamics in neural networks. As described in this paper, the decomposition of high-dimensional neural networks into low-dimensional neural networks equivalent to the original neural networks yields neural networks that have no critical point based on the hierarchical structure. Concretely, the following three cases are shown: (a A 2-2-2 real-valued NN is constructed from a 1-1-1 complex-valued NN. (b A 4-4-4 real-valued NN is constructed from a 1-1-1 quaternionic NN. (c A 2-2-2 complex-valued NN is constructed from a 1-1-1 quaternionic NN. Those NNs described above do not suffer from a negative effect by singular points during learning comparatively because they have no critical point based on a hierarchical structure.

  19. Hierarchical content-based image retrieval by dynamic indexing and guided search

    Science.gov (United States)

    You, Jane; Cheung, King H.; Liu, James; Guo, Linong

    2003-12-01

    This paper presents a new approach to content-based image retrieval by using dynamic indexing and guided search in a hierarchical structure, and extending data mining and data warehousing techniques. The proposed algorithms include: a wavelet-based scheme for multiple image feature extraction, the extension of a conventional data warehouse and an image database to an image data warehouse for dynamic image indexing, an image data schema for hierarchical image representation and dynamic image indexing, a statistically based feature selection scheme to achieve flexible similarity measures, and a feature component code to facilitate query processing and guide the search for the best matching. A series of case studies are reported, which include a wavelet-based image color hierarchy, classification of satellite images, tropical cyclone pattern recognition, and personal identification using multi-level palmprint and face features.

  20. ENERGY EFFICIENT HIERARCHICAL CLUSTER-BASED ROUTING FOR WIRELESS SENSOR NETWORKS

    OpenAIRE

    Shideh Sadat Shirazi; Aboulfazl Torqi Haqiqat

    2015-01-01

    In this paper we propose an energy efficient routing algorithm based on hierarchical clustering in wireless sensor networks (WSNs).This algorithm decreases the energy consumption of nodes and helps to increase the lifetime of sensor networks. To achieve this goal, this research network is divided into 4segments that lead to uniform energy consumption among sensor nodes. We also propose a multi-step clustering method to send and receive data from nodes to the base station. The s...

  1. The Robustness of Content-Based Search in Hierarchical Peer to Peer Networks

    OpenAIRE

    Renda, Maria Elena; Callan, Jamie

    2004-01-01

    Hierarchical Peer to Peer (P2P) networks with multiple directory services have quickly become one of the dominant architectures for large-scale file sharing due to their effectiveness and efficiency. Recent research argues that such networks are also an effective method of providing large-scale content-based federated search of text-based digital libraries. In both cases the directory services are critical resources that are subject to attack or failure, but the latter architecture may be par...

  2. HCBLS: A Hierarchical Cluster-Based Location Service in Urban Environment

    OpenAIRE

    Raik Aissaoui; Amine Dhraief; Abdelfettah Belghith; Hamid Menouar; Hassan Mathkour; Fethi Filali; Adnan Abu-Dayya

    2015-01-01

    Vehicle location information is central to many location-based services and applications in VANETs. Tracking vehicles positions and maintaining an accurate up-to-date view of the entire network are not easy due to the high mobility of vehicles and consequently rapid topology changes. The design of a scalable, accurate, and efficient location service is still a very challenging issue. In this paper, we propose a lightweight hierarchical cluster-based location service in city environments (HCBL...

  3. Borrowing strengh in hierarchical Bayes: Posterior concentration of the Dirichlet base measure

    OpenAIRE

    Nguyen, XuanLong

    2013-01-01

    This paper studies posterior concentration behavior of the base probability measure of a Dirichlet measure, given observations associated with the sampled Dirichlet processes, as the number of observations tends to infinity. The base measure itself is endowed with another Dirichlet prior, a construction known as the hierarchical Dirichlet processes (Teh et al. [J. Amer. Statist. Assoc. 101 (2006) 1566–1581]). Convergence rates are established in transportation distances (i.e., Wasserstein met...

  4. Hierarchical photocatalysts.

    Science.gov (United States)

    Li, Xin; Yu, Jiaguo; Jaroniec, Mietek

    2016-05-01

    As a green and sustainable technology, semiconductor-based heterogeneous photocatalysis has received much attention in the last few decades because it has potential to solve both energy and environmental problems. To achieve efficient photocatalysts, various hierarchical semiconductors have been designed and fabricated at the micro/nanometer scale in recent years. This review presents a critical appraisal of fabrication methods, growth mechanisms and applications of advanced hierarchical photocatalysts. Especially, the different synthesis strategies such as two-step templating, in situ template-sacrificial dissolution, self-templating method, in situ template-free assembly, chemically induced self-transformation and post-synthesis treatment are highlighted. Finally, some important applications including photocatalytic degradation of pollutants, photocatalytic H2 production and photocatalytic CO2 reduction are reviewed. A thorough assessment of the progress made in photocatalysis may open new opportunities in designing highly effective hierarchical photocatalysts for advanced applications ranging from thermal catalysis, separation and purification processes to solar cells. PMID:26963902

  5. Cost of Multicast Logical Key Tree Based on Hierarchical Data Processing

    Institute of Scientific and Technical Information of China (English)

    ZHOU Fucai; XU Jian; LI Ting

    2006-01-01

    How to design a multicast key management system with high performance is a hot issue now. This paper will apply the idea of hierarchical data processing to construct a common analytic model based on directed logical key tree and supply two important metrics to this problem: re-keying cost and key storage cost. The paper gives the basic theory to the hierarchical data processing and the analyzing model to multicast key management based on logical key tree. It has been proved that the 4-ray tree has the best performance in using these metrics. The key management problem is also investigated based on user probability model, and gives two evaluating parameters to re-keying and key storage cost.

  6. Hierarchical Object-Based Visual Attention for Machine Vision

    OpenAIRE

    Sun, Yaoru

    2003-01-01

    Human vision uses mechanisms of covert attention to selectively process interesting information and overt eye movements to extend this selectivity ability. Thus, visual tasks can be effectively dealt with by limited processing resources. Modelling visual attention for machine vision systems is not only critical but also challenging. In the machine vision literature there have been many conventional attention models developed but they are all space-based only and cannot perform ...

  7. Performance evaluation of hierarchical TTL-based cache networks

    OpenAIRE

    Choungmo Fofack, Nicaise; Nain, Philippe; Neglia, Giovanni; Towsley, Don

    2014-01-01

    There has been considerable research on the performance analysis of on-demand caching replacement policies like Least-Recently-Used (LRU), First-In-First-Out (FIFO) or Random (RND). Much progress has been made on the analysis of a single cache running these algorithms. However it has been almost impossible to extend the results to networks of caches. In this paper, we introduce a Time-To-Live (TTL) based caching model, that assigns a timer to each content stored in the cache and redraws it ev...

  8. Inferring a district-based hierarchical structure of social contacts from census data.

    Directory of Open Access Journals (Sweden)

    Z Yu

    Full Text Available Researchers have recently paid attention to social contact patterns among individuals due to their useful applications in such areas as epidemic evaluation and control, public health decisions, chronic disease research and social network research. Although some studies have estimated social contact patterns from social networks and surveys, few have considered how to infer the hierarchical structure of social contacts directly from census data. In this paper, we focus on inferring an individual's social contact patterns from detailed census data, and generate various types of social contact patterns such as hierarchical-district-structure-based, cross-district and age-district-based patterns. We evaluate newly generated contact patterns derived from detailed 2011 Hong Kong census data by incorporating them into a model and simulation of the 2009 Hong Kong H1N1 epidemic. We then compare the newly generated social contact patterns with the mixing patterns that are often used in the literature, and draw the following conclusions. First, the generation of social contact patterns based on a hierarchical district structure allows for simulations at different district levels. Second, the newly generated social contact patterns reflect individuals social contacts. Third, the newly generated social contact patterns improve the accuracy of the SEIR-based epidemic model.

  9. A Vascular-Network-Based Nonuniform Hierarchical Fault-Tolerant Routing Algorithm for Wireless Sensor Networks

    OpenAIRE

    Hongbing Li; Peng Gao; Qingyu Xiong; Weiren Shi; Qiang Chen

    2012-01-01

    Fault tolerance is the key technology in wireless sensor networks which attracts many research interests. Aiming at the issue that the nodes' failures affect the network's stability and service quality, a vascular-network-based fault-tolerant routing algorithm is presented by nonuniform hierarchical clustering. According to the distribution characteristics of the vascular network and inspirations to the fault tolerance for wireless sensor networks, a mathematical model and network topology ar...

  10. Policy based intrusion detection and response system in hierarchical WSN architecture

    OpenAIRE

    Mamun, Mohammad Saiful Islam; Kabir, A. F. M Sultanul; Hossen, Md. Sakhawat; Khan, Md. Razib Hayat

    2012-01-01

    In recent years, wireless sensor network becomes popular both in civil and military jobs. However, security is one of the significant challenges for sensor network because of their deployment in open and unprotected environment. As cryptographic mechanism is not enough to protect sensor network from external attacks, intrusion detection system (IDS) needs to be introduced. In this paper we propose a policy based IDS for hierarchical architecture that fits the current demands and restrictions ...

  11. Enforcing Access Control in Virtual Organizations Using Hierarchical Attribute-Based Encryption

    OpenAIRE

    Asim, Muhammad; Ignatenko, Tanya; Petkovic, Milan; Trivellato, Daniel; Zannone, Nicola

    2012-01-01

    Virtual organizations are dynamic, inter-organizational collaborations that involve systems and services belonging to different security domains. Several solutions have been proposed to guarantee the enforcement of the access control policies protecting the information exchanged in a distributed system, but none of them addresses the dynamicity characterizing virtual organizations. In this paper we propose a dynamic hierarchical attribute-based encryption (D-HABE) scheme that allows the insti...

  12. Hierarchical Web Page Classification Based on a Topic Model and Neighboring Pages Integration

    OpenAIRE

    Wongkot Sriurai; Phayung Meesad; Choochart Haruechaiyasak

    2010-01-01

    Most Web page classification models typically apply the bag of words (BOW) model to represent the feature space. The original BOW representation, however, is unable to recognize semantic relationships between terms. One possible solution is to apply the topic model approach based on the Latent Dirichlet Allocation algorithm to cluster the term features into a set of latent topics. Terms assigned into the same topic are semantically related. In this paper, we propose a novel hierarchical class...

  13. Robust Superhydrophobic Foam: A Graphdiyne-Based Hierarchical Architecture for Oil/Water Separation.

    Science.gov (United States)

    Gao, Xin; Zhou, Jingyuan; Du, Ran; Xie, Ziqian; Deng, Shibin; Liu, Rong; Liu, Zhongfan; Zhang, Jin

    2016-01-01

    Robust superhydrophobic foam is fabricated by combining an ordered graphdiyne-based hierarchical structure with a low-surface-energy coating. This foam shows not only superhydrophobicity both in air (≈160.1°) and in oil (≈171.0°), but also high resistance toward abrasion cycles. Owing to its 3D porous structures and numerous superhydrophobic surfaces, it can easily separate oil from water with high efficiency and good recyclability. PMID:26551876

  14. One-dimensional ZnS-based Hetero-, Core/shell and Hierarchical Nanostructures

    Institute of Scientific and Technical Information of China (English)

    Xiaosheng FANG; Ujjal K.Gautam; Yoshio BANDO; Dmitri GOLBERG

    2008-01-01

    A focus of the current nanotechnology has shifted from routine fabrication of nanostructures to designing functional electronic devices and realizing their immense potentials for applications. Due to infusion of multifunctionality into a single system, the utilization of hetero-, core/shell and hierarchical nanostructures has become the key issue for building such devices. ZnS, due to its direct wide bandgap, high index of refraction, high transparency in the visible range and intrinsic polarity, is one of the most useful semiconductors for a wide range of electronics applications. This article provides a dense review of the state-of-the-art research activities in one-dimensional (1D) ZnS-based hetero-, core/shell and hierarchical nanostructures. The particular emphasis is put on their syntheses and applications.

  15. Monitoring Post Disturbance Forest Regeneration with Hierarchical Object-Based Image Analysis

    Directory of Open Access Journals (Sweden)

    L. Monika Moskal

    2013-10-01

    Full Text Available The main goal of this exploratory project was to quantify seedling density in post fire regeneration sites, with the following objectives: to evaluate the application of second order image texture (SOIT in image segmentation, and to apply the object-based image analysis (OBIA approach to develop a hierarchical classification. With the utilization of image texture we successfully developed a methodology to classify hyperspatial (high-spatial imagery to fine detail level of tree crowns, shadows and understory, while still allowing discrimination between density classes and mature forest versus burn classes. At the most detailed hierarchical Level I classification accuracies reached 78.8%, a Level II stand density classification produced accuracies of 89.1% and the same accuracy was achieved by the coarse general classification at Level III. Our interpretation of these results suggests hyperspatial imagery can be applied to post-fire forest density and regeneration mapping.

  16. Controlling Torque Distribution for Parallel Hybrid Vehicle Based on Hierarchical Structure Fuzzy Logic

    Institute of Scientific and Technical Information of China (English)

    HuangMiao-hua; JinGuo-dong

    2003-01-01

    The Hierarchical Structure Fuzzy Logic Control(HSFLC) strategies of torque distribute for Parallel Hybrid Electric Vehicle (PHEV) in the mocle of operation of the vehicle i. e. , acceleration, cruise, deceleration etc. have been studied. Using secondly developed the hybrid vehicle simulation tool ADVISOR, the dynamic model of PHEV has been set up by MATLAB/SIMULINK. The engine, motor as well as the battery characteristics have been studied. Simulation results show that the proposed hierarchical structured fuzzy logic control strategy is effective over the entire operating range of the vehicle in terms of fuel economy. Based on the analyses of the simulation results and driver's experiences, a fuzzy controller is designed and developed to control the torque distribution. The controller is evaluated via hardware-in-the-loop simulator (HILS). The results show that controller verify its value.

  17. A CDMA Based Scalable Hierarchical Architecture for Network-On-Chip

    Directory of Open Access Journals (Sweden)

    Mohamed A. Abd El Ghany

    2012-09-01

    Full Text Available A Scalable hierarchical architecture based Code-Division Multiple Access (CDMA is proposed for high performance Network-on-Chip (NoC. This hierarchical architecture provides the integration of a large number of IPs in a single on-chip system. The network encoding and decoding schemes for CDMA transmission are provided. The proposed CDMA NoC architecture is compared to the conventional architecture in terms of latency, area and power dissipation. The overall area required to implement the proposed CDMA NoC design is reduced by 24.2%. The design decreases the latency of the network by 40%. The total power consumption required to achieve the proposed design is also decreased by 25%.

  18. A Hierarchical Aggregation Approach for Indicators Based on Data Envelopment Analysis and Analytic Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Mohammad Sadegh Pakkar

    2016-01-01

    Full Text Available This research proposes a hierarchical aggregation approach using Data Envelopment Analysis (DEA and Analytic Hierarchy Process (AHP for indicators. The core logic of the proposed approach is to reflect the hierarchical structures of indicators and their relative priorities in constructing composite indicators (CIs, simultaneously. Under hierarchical structures, the indicators of similar characteristics can be grouped into sub-categories and further into categories. According to this approach, we define a domain of composite losses, i.e., a reduction in CI values, based on two sets of weights. The first set represents the weights of indicators for each Decision Making Unit (DMU with the minimal composite loss, and the second set represents the weights of indicators bounded by AHP with the maximal composite loss. Using a parametric distance model, we explore various ranking positions for DMUs while the indicator weights obtained from a three-level DEA-based CI model shift towards the corresponding weights bounded by AHP. An illustrative example of road safety performance indicators (SPIs for a set of European countries highlights the usefulness of the proposed approach.

  19. Space-Time Hierarchical-Graph Based Cooperative Localization in Wireless Sensor Networks

    Science.gov (United States)

    Lv, Tiejun; Gao, Hui; Li, Xiaopeng; Yang, Shaoshi; Hanzo, Lajos

    2016-01-01

    It has been shown that cooperative localization is capable of improving both the positioning accuracy and coverage in scenarios where the global positioning system (GPS) has a poor performance. However, due to its potentially excessive computational complexity, at the time of writing the application of cooperative localization remains limited in practice. In this paper, we address the efficient cooperative positioning problem in wireless sensor networks. A space-time hierarchical-graph based scheme exhibiting fast convergence is proposed for localizing the agent nodes. In contrast to conventional methods, agent nodes are divided into different layers with the aid of the space-time hierarchical-model and their positions are estimated gradually. In particular, an information propagation rule is conceived upon considering the quality of positional information. According to the rule, the information always propagates from the upper layers to a certain lower layer and the message passing process is further optimized at each layer. Hence, the potential error propagation can be mitigated. Additionally, both position estimation and position broadcasting are carried out by the sensor nodes. Furthermore, a sensor activation mechanism is conceived, which is capable of significantly reducing both the energy consumption and the network traffic overhead incurred by the localization process. The analytical and numerical results provided demonstrate the superiority of our space-time hierarchical-graph based cooperative localization scheme over the benchmarking schemes considered.

  20. A hierarchical lattice spring model to simulate the mechanics of 2-D materials-based composites

    Directory of Open Access Journals (Sweden)

    Lucas eBrely

    2015-07-01

    Full Text Available In the field of engineering materials, strength and toughness are typically two mutually exclusive properties. Structural biological materials such as bone, tendon or dentin have resolved this conflict and show unprecedented damage tolerance, toughness and strength levels. The common feature of these materials is their hierarchical heterogeneous structure, which contributes to increased energy dissipation before failure occurring at different scale levels. These structural properties are the key to exceptional bioinspired material mechanical properties, in particular for nanocomposites. Here, we develop a numerical model in order to simulate the mechanisms involved in damage progression and energy dissipation at different size scales in nano- and macro-composites, which depend both on the heterogeneity of the material and on the type of hierarchical structure. Both these aspects have been incorporated into a 2-dimensional model based on a Lattice Spring Model, accounting for geometrical nonlinearities and including statistically-based fracture phenomena. The model has been validated by comparing numerical results to continuum and fracture mechanics results as well as finite elements simulations, and then employed to study how structural aspects impact on hierarchical composite material properties. Results obtained with the numerical code highlight the dependence of stress distributions on matrix properties and reinforcement dispersion, geometry and properties, and how failure of sacrificial elements is directly involved in the damage tolerance of the material. Thanks to the rapidly developing field of nanocomposite manufacture, it is already possible to artificially create materials with multi-scale hierarchical reinforcements. The developed code could be a valuable support in the design and optimization of these advanced materials, drawing inspiration and going beyond biological materials with exceptional mechanical properties.

  1. A hierarchical lattice spring model to simulate the mechanics of 2-D materials-based composites

    Science.gov (United States)

    Brely, Lucas; Bosia, Federico; Pugno, Nicola

    2015-07-01

    In the field of engineering materials, strength and toughness are typically two mutually exclusive properties. Structural biological materials such as bone, tendon or dentin have resolved this conflict and show unprecedented damage tolerance, toughness and strength levels. The common feature of these materials is their hierarchical heterogeneous structure, which contributes to increased energy dissipation before failure occurring at different scale levels. These structural properties are the key to exceptional bioinspired material mechanical properties, in particular for nanocomposites. Here, we develop a numerical model in order to simulate the mechanisms involved in damage progression and energy dissipation at different size scales in nano- and macro-composites, which depend both on the heterogeneity of the material and on the type of hierarchical structure. Both these aspects have been incorporated into a 2-dimensional model based on a Lattice Spring Model, accounting for geometrical nonlinearities and including statistically-based fracture phenomena. The model has been validated by comparing numerical results to continuum and fracture mechanics results as well as finite elements simulations, and then employed to study how structural aspects impact on hierarchical composite material properties. Results obtained with the numerical code highlight the dependence of stress distributions on matrix properties and reinforcement dispersion, geometry and properties, and how failure of sacrificial elements is directly involved in the damage tolerance of the material. Thanks to the rapidly developing field of nanocomposite manufacture, it is already possible to artificially create materials with multi-scale hierarchical reinforcements. The developed code could be a valuable support in the design and optimization of these advanced materials, drawing inspiration and going beyond biological materials with exceptional mechanical properties.

  2. Hierarchical graphs for better annotations of rule-based models of biochemical systems

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Bin [Los Alamos National Laboratory; Hlavacek, William [Los Alamos National Laboratory

    2009-01-01

    In the graph-based formalism of the BioNetGen language (BNGL), graphs are used to represent molecules, with a colored vertex representing a component of a molecule, a vertex label representing the internal state of a component, and an edge representing a bond between components. Components of a molecule share the same color. Furthermore, graph-rewriting rules are used to represent molecular interactions, with a rule that specifies addition (removal) of an edge representing a class of association (dissociation) reactions and with a rule that specifies a change of vertex label representing a class of reactions that affect the internal state of a molecular component. A set of rules comprises a mathematical/computational model that can be used to determine, through various means, the system-level dynamics of molecular interactions in a biochemical system. Here, for purposes of model annotation, we propose an extension of BNGL that involves the use of hierarchical graphs to represent (1) relationships among components and subcomponents of molecules and (2) relationships among classes of reactions defined by rules. We illustrate how hierarchical graphs can be used to naturally document the structural organization of the functional components and subcomponents of two proteins: the protein tyrosine kinase Lck and the T cell receptor (TCR)/CD3 complex. Likewise, we illustrate how hierarchical graphs can be used to document the similarity of two related rules for kinase-catalyzed phosphorylation of a protein substrate. We also demonstrate how a hierarchical graph representing a protein can be encoded in an XML-based format.

  3. Analysis of acoustic cardiac signals for heart rate variability and murmur detection using nonnegative matrix factorization-based hierarchical decomposition

    DEFF Research Database (Denmark)

    Shah, Ghafoor; Koch, Peter; Papadias, Constantinos B.

    novel method based on hierarchical decomposition of the single channel mixture using various nonnegative matrix factorization techniques is proposed, which provides unsupervised clustering of the underlying component signals. HRV is determined over the recovered normal cardiac acoustic signals. This...

  4. Prolonging the Lifetime of Wireless Sensor Networks Interconnected to Fixed Network Using Hierarchical Energy Tree Based Routing Algorithm

    OpenAIRE

    2014-01-01

    This research work proposes a mathematical model for the lifetime of wireless sensor networks (WSN). It also proposes an energy efficient routing algorithm for WSN called hierarchical energy tree based routing algorithm (HETRA) based on hierarchical energy tree constructed using the available energy in each node. The energy efficiency is further augmented by reducing the packet drops using exponential congestion control algorithm (TCP/EXP). The algorithms are evaluated in WSNs interconnected ...

  5. Face Recognition Algorithm Based on Doubly Truncated Gaussian Mixture Model Using Hierarchical Clustering Algorithm

    Directory of Open Access Journals (Sweden)

    D. Haritha

    2012-03-01

    Full Text Available A robust and efficient face recognition system was developed and evaluated. The each individual face is characterized by 2D-DCT coefficients which follows a finite mixture of doubly truncated Gaussian distribution. In modelling the features vector of the face the number of components (in the mixture model are determined by hierarchical clustering. The model parameters are estimated using EM algorithm. The face recognition algorithm is developed by maximum likelihood under Baysian frame. The method was tested on two available face databases namely JNTUK and yale. The recognition rates computed for different methods of face recognition have revealed that the proposed method performs very well when compared to the other approaches. It is also observed that the proposed system require less number of DCT coefficients in each block and serve well even with large and small databases. The hybridization of hierarchical clustering with model based approach has significantly improved the recognition rate of the system even with the simple features like DCT. Keywords: Face recognition system, doubly truncated Gaussian mixture model, Hierarchical clustering algorithm, DCT coefficients.

  6. Hierarchical structure of the countries based on electricity consumption and economic growth

    Science.gov (United States)

    Kantar, Ersin; Aslan, Alper; Deviren, Bayram; Keskin, Mustafa

    2016-07-01

    We investigate the hierarchical structures of countries based on electricity consumption and economic growth by using the real amounts of their consumption over a certain time period. We use electricity consumption data to detect the topological properties of 64 countries from 1971 to 2008. These countries are divided into three clusters: low income group, middle income group and high income group countries. Firstly, a relationship between electricity consumption and economic growth is investigated by using the concept of hierarchical structure methods (minimal spanning tree (MST) and hierarchical tree (HT)). Secondly, we perform bootstrap techniques to investigate a value of the statistical reliability to the links of the MST. Finally, we use a clustering linkage procedure in order to observe the cluster structure more clearly. The results of the structural topologies of these trees are as follows: (i) we identified different clusters of countries according to their geographical location and economic growth, (ii) we found a strong relation between energy consumption and economic growth for all the income groups considered in this study and (iii) the results are in good agreement with the causal relationship between electricity consumption and economic growth.

  7. Single Vs Hierarchical Population-Based Memetic Algorithm for Sat-Encoded Industrial Problems:A Statistical Comparison

    Directory of Open Access Journals (Sweden)

    Noureddine Bouhmala

    2012-11-01

    Full Text Available In this work, a hierarchical population-based memetic algorithm for solving the satisfiability problem is presented. The approach suggests looking at the evolution as a hierarchical process evolving from a coarse population where the basic unit of a gene is composed of cluster of variables that represent the problem to a fine population where each gene represents a single variable. The optimization process is carried out by letting the converged population at a child level serve as the initial population to the parent level. A benchmark composed of industrial instances is used to compare the effectiveness of the hierarchical approach against its single-level counterpart.

  8. Shape-based human detection and segmentation via hierarchical part-template matching.

    Science.gov (United States)

    Lin, Zhe; Davis, Larry S

    2010-04-01

    We propose a shape-based, hierarchical part-template matching approach to simultaneous human detection and segmentation combining local part-based and global shape-template-based schemes. The approach relies on the key idea of matching a part-template tree to images hierarchically to detect humans and estimate their poses. For learning a generic human detector, a pose-adaptive feature computation scheme is developed based on a tree matching approach. Instead of traditional concatenation-style image location-based feature encoding, we extract features adaptively in the context of human poses and train a kernel-SVM classifier to separate human/nonhuman patterns. Specifically, the features are collected in the local context of poses by tracing around the estimated shape boundaries. We also introduce an approach to multiple occluded human detection and segmentation based on an iterative occlusion compensation scheme. The output of our learned generic human detector can be used as an initial set of human hypotheses for the iterative optimization. We evaluate our approaches on three public pedestrian data sets (INRIA, MIT-CBCL, and USC-B) and two crowded sequences from Caviar Benchmark and Munich Airport data sets. PMID:20224118

  9. Identifying Hierarchical and Overlapping Protein Complexes Based on Essential Protein-Protein Interactions and “Seed-Expanding” Method

    OpenAIRE

    Jun Ren; Wei Zhou; Jianxin Wang

    2014-01-01

    Many evidences have demonstrated that protein complexes are overlapping and hierarchically organized in PPI networks. Meanwhile, the large size of PPI network wants complex detection methods have low time complexity. Up to now, few methods can identify overlapping and hierarchical protein complexes in a PPI network quickly. In this paper, a novel method, called MCSE, is proposed based on λ-module and “seed-expanding.” First, it chooses seeds as essential PPIs or edges with high edge clusterin...

  10. Hierarchical Grid-based Multi-People Tracking-by-Detection With Global Optimization.

    Science.gov (United States)

    Chen, Lili; Wang, Wei; Panin, Giorgio; Knoll, Alois

    2015-11-01

    We present a hierarchical grid-based, globally optimal tracking-by-detection approach to track an unknown number of targets in complex and dense scenarios, particularly addressing the challenges of complex interaction and mutual occlusion. Frame-by-frame detection is performed by hierarchical likelihood grids, matching shape templates through a fast oriented distance transform. To allow recovery from misdetections, common heuristics such as nonmaxima suppression within observations is eschewed. Within a discretized state-space, the data association problem is formulated as a grid-based network flow model, resulting in a convex problem casted into an integer linear programming form, giving a global optimal solution. In addition, we show how a behavior cue (body orientation) can be integrated into our association affinity model, providing valuable hints for resolving ambiguities between crossing trajectories. Unlike traditional motion-based approaches, we estimate body orientation by a hybrid methodology, which combines the merits of motion-based and 3D appearance-based orientation estimation, thus being capable of dealing also with still-standing or slowly moving targets. The performance of our method is demonstrated through experiments on a large variety of benchmark video sequences, including both indoor and outdoor scenarios. PMID:26151936

  11. Spatial Object Aggregation Based on Data Structure,Local Triangulation and Hierarchical Analyzing Method

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper focuses on the methods and process of spatial aggregation based on semantic and geometric characteristics of spatial objects and relations among the objects with the help of spatial data structure (Formal Data Structure),the Local Constrained Delaunay Triangulations and semantic hierarchy.The adjacent relation among connected objects and unconnected objects has been studied through constrained triangle as elementary processing unit in aggregation operation.The hierarchical semantic analytical matrix is given for analyzing the similarity between objects types and between objects.Several different cases of aggregation have been presented in this paper.

  12. An Intrusion Detection System Based on Multi-Level Clustering for Hierarchical Wireless Sensor Networks.

    Science.gov (United States)

    Butun, Ismail; Ra, In-Ho; Sankar, Ravi

    2015-01-01

    In this work, an intrusion detection system (IDS) framework based on multi-level clustering for hierarchical wireless sensor networks is proposed. The framework employs two types of intrusion detection approaches: (1) "downward-IDS (D-IDS)" to detect the abnormal behavior (intrusion) of the subordinate (member) nodes; and (2) "upward-IDS (U-IDS)" to detect the abnormal behavior of the cluster heads. By using analytical calculations, the optimum parameters for the D-IDS (number of maximum hops) and U-IDS (monitoring group size) of the framework are evaluated and presented. PMID:26593915

  13. An Intrusion Detection System Based on Multi-Level Clustering for Hierarchical Wireless Sensor Networks

    OpenAIRE

    Ismail Butun; In-Ho Ra; Ravi Sankar

    2015-01-01

    In this work, an intrusion detection system (IDS) framework based on multi-level clustering for hierarchical wireless sensor networks is proposed. The framework employs two types of intrusion detection approaches: (1) “downward-IDS (D-IDS)” to detect the abnormal behavior (intrusion) of the subordinate (member) nodes; and (2) “upward-IDS (U-IDS)” to detect the abnormal behavior of the cluster heads. By using analytical calculations, the optimum parameters for the D-IDS (number of maximum hops...

  14. Hierarchical Downlink Resource Management Framework for OFDMA based WiMAX Systems

    DEFF Research Database (Denmark)

    Wang, Hua; Iversen, Villy Bæk

    2008-01-01

    IEEE 802.16, known as WiMAX, has received much attention for its capability to support multiple types of applications with diverse QoS requirements. Beyond what the standard has defined, radio resource management (RRM) still remains an open issue. In this paper, we propose a hierarchical downlink...... resource management framework for OFDMA based WiMAX systems. Our framework consists of a dynamic resource allocation (DRA) module and a connection admission control (CAC) module. DRA emphasizes on how to share the limited radio resources in term of subchannels and time slots among WiMAX subscribers...

  15. Hierarchical model-based predictive control of a power plant portfolio

    DEFF Research Database (Denmark)

    Edlund, Kristian; Bendtsen, Jan Dimon; Jørgensen, John Bagterp

    2011-01-01

    One of the main difficulties in large-scale implementation of renewable energy in existing power systems is that the production from renewable sources is difficult to predict and control. For this reason, fast and efficient control of controllable power producing units – so-called “portfolio...... control” – becomes increasingly important as the ratio of renewable energy in a power system grows. As a consequence, tomorrow's “smart grids” require highly flexible and scalable control systems compared to conventional power systems. This paper proposes a hierarchical model-based predictive control...

  16. Elastic properties of chiral, anti-chiral, and hierarchical honeycombs: A simple energy-based approach

    Directory of Open Access Journals (Sweden)

    Davood Mousanezhad

    2016-03-01

    Full Text Available The effects of two geometric refinement strategies widespread in natural structures, chirality and self-similar hierarchy, on the in-plane elastic response of two-dimensional honeycombs were studied systematically. Simple closed-form expressions were derived for the elastic moduli of several chiral, anti-chiral, and hierarchical honeycombs with hexagon and square based networks. Finite element analysis was employed to validate the analytical estimates of the elastic moduli. The results were also compared with the numerical and experimental data available in the literature. We found that introducing a hierarchical refinement increases the Young’s modulus of hexagon based honeycombs while decreases their shear modulus. For square based honeycombs, hierarchy increases the shear modulus while decreasing their Young’s modulus. Introducing chirality was shown to always decrease the Young’s modulus and Poisson’s ratio of the structure. However, chirality remains the only route to auxeticity. In particular, we found that anti-tetra-chiral structures were capable of simultaneously exhibiting anisotropy, auxeticity, and remarkably low shear modulus as the magnitude of the chirality of the unit cell increases.

  17. A test sheet generating algorithm based on intelligent genetic algorithm and hierarchical planning

    Science.gov (United States)

    Gu, Peipei; Niu, Zhendong; Chen, Xuting; Chen, Wei

    2013-03-01

    In recent years, computer-based testing has become an effective method to evaluate students' overall learning progress so that appropriate guiding strategies can be recommended. Research has been done to develop intelligent test assembling systems which can automatically generate test sheets based on given parameters of test items. A good multisubject test sheet depends on not only the quality of the test items but also the construction of the sheet. Effective and efficient construction of test sheets according to multiple subjects and criteria is a challenging problem. In this paper, a multi-subject test sheet generation problem is formulated and a test sheet generating approach based on intelligent genetic algorithm and hierarchical planning (GAHP) is proposed to tackle this problem. The proposed approach utilizes hierarchical planning to simplify the multi-subject testing problem and adopts genetic algorithm to process the layered criteria, enabling the construction of good test sheets according to multiple test item requirements. Experiments are conducted and the results show that the proposed approach is capable of effectively generating multi-subject test sheets that meet specified requirements and achieve good performance.

  18. Hierarchical Calibration and Validation of Computational Fluid Dynamics Models for Solid Sorbent-based Carbon Capture

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Canhai; Xu, Zhijie; Pan, Wenxiao; Sun, Xin; Storlie, Curtis; Marcy, Peter; Dietiker, Jeff; Li, Tingwen; Spenik, James

    2016-02-22

    To quantify the predictive confidence of a solid sorbent-based carbon capture design, a hierarchical validation methodology—consisting of basic unit problems with increasing physical complexity coupled with filtered model-based geometric upscaling has been developed and implemented. This paper describes the computational fluid dynamics (CFD) multi-phase reactive flow simulations and the associated data flows among different unit problems performed within the said hierarchical validation approach. The bench-top experiments used in this calibration and validation effort were carefully designed to follow the desired simple-to-complex unit problem hierarchy, with corresponding data acquisition to support model parameters calibrations at each unit problem level. A Bayesian calibration procedure is employed and the posterior model parameter distributions obtained at one unit-problem level are used as prior distributions for the same parameters in the next-tier simulations. Overall, the results have demonstrated that the multiphase reactive flow models within MFIX can be used to capture the bed pressure, temperature, CO2 capture capacity, and kinetics with quantitative accuracy. The CFD modeling methodology and associated uncertainty quantification techniques presented herein offer a solid framework for estimating the predictive confidence in the virtual scale up of a larger carbon capture device.

  19. An ontology-based hierarchical semantic modeling approach to clinical pathway workflows.

    Science.gov (United States)

    Ye, Yan; Jiang, Zhibin; Diao, Xiaodi; Yang, Dong; Du, Gang

    2009-08-01

    This paper proposes an ontology-based approach of modeling clinical pathway workflows at the semantic level for facilitating computerized clinical pathway implementation and efficient delivery of high-quality healthcare services. A clinical pathway ontology (CPO) is formally defined in OWL web ontology language (OWL) to provide common semantic foundation for meaningful representation and exchange of pathway-related knowledge. A CPO-based semantic modeling method is then presented to describe clinical pathways as interconnected hierarchical models including the top-level outcome flow and intervention workflow level along a care timeline. Furthermore, relevant temporal knowledge can be fully represented by combing temporal entities in CPO and temporal rules based on semantic web rule language (SWRL). An illustrative example about a clinical pathway for cesarean section shows the applicability of the proposed methodology in enabling structured semantic descriptions of any real clinical pathway. PMID:19539278

  20. HIERARCHICAL DESIGN BASED INTRUSION DETECTION SYSTEM FOR WIRELESS AD HOC SENSOR NETWORK

    Directory of Open Access Journals (Sweden)

    Mohammad Saiful Islam Mamun

    2010-07-01

    Full Text Available In recent years, wireless ad hoc sensor network becomes popular both in civil and military jobs.However, security is one of the significant challenges for sensor network because of their deploymentin open and unprotected environment. As cryptographic mechanism is not enough to protect sensornetwork from external attacks, intrusion detection system needs to be introduced. Though intrusionprevention mechanism is one of the major and efficient methods against attacks, but there might besome attacks for which prevention method is not known. Besides preventing the system from someknown attacks, intrusion detection system gather necessary information related to attack technique andhelp in the development of intrusion prevention system. In addition to reviewing the present attacksavailable in wireless sensor network this paper examines the current efforts to intrusion detectionsystem against wireless sensor network. In this paper we propose a hierarchical architectural designbased intrusion detection system that fits the current demands and restrictions of wireless ad hocsensor network. In this proposed intrusion detection system architecture we followed clusteringmechanism to build a four level hierarchical network which enhances network scalability to largegeographical area and use both anomaly and misuse detection techniques for intrusion detection. Weintroduce policy based detection mechanism as well as intrusion response together with GSM cellconcept for intrusion detection architecture.

  1. Fabrication of semi-transparent superoleophobic thin film from fabrics and nanoparticle-based hierarchical structure

    Directory of Open Access Journals (Sweden)

    Nishizawa S.

    2013-08-01

    Full Text Available Superoleophobic thin films have many potential applications including fluid transfer, fluid power systems, stain resistant and antifouling materials, and microfluidics among others. Transparency is also desired with superhydrophobicity for their numerous applications; however transparency and oleophobicity are almost incompatible relationship with each other in the point of surface structure. Because oleophobicity required rougher structure at nano-micro scale than hydrophobicity, and these rough structure brings light scattering. So far, there is very few report of the compatible of transparency and superoleophobicity. In this report, we proposed the see-through type fabrics using the nanoparticle-based hierarchical structure thin film for improving both of oleophobicity and transparency. The vacant space between fibrils of fabrics has two important roles: the one is to through the light, another one is to introduce air layer to realize Cassie state of liquid droplet on thin film. To realize the low surface energy and nanoscale rough structure surface on fibrils, we used the spray method with perfluoroalkyl methacrylic copolymer (PMC, silica nano particles and volatile solvent. From the SEM image, the hierarchical structures of nanoparticle were formed uniformly on the fabrics. The transparency of thin film obtained was approximately 61% and the change of transparency between pre-coated fabrics and coated was 11%. From investigation of the surface wettability, the contact angles of oils (rapeseed oil and hexadecane and water droplet on the fabricated film were over 150 degree.

  2. Hierarchical composites: Analysis of damage evolution based on fiber bundle model

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon

    2011-01-01

    A computational model of multiscale composites is developed on the basis of the fiber bundle model with the hierarchical load sharing rule, and employed to study the effect of the microstructures of hierarchical composites on their damage resistance. Two types of hierarchical materials were...... considered: “hierarchical tree” (bundles-of-bundles of fibers) and self-similar particle and fiber reinforced composite (in which reinforcements at each scale level represents composites in turn consisting of lower level reinforcements and matrix). For the case of the hierarchical tree (“bundle...... hierarchy levels. The effect of mixed fiber and particle reinforcement on the damage resistance of the hierarchical composites is investigated as well....

  3. Immunophenotype Discovery, Hierarchical Organization, and Template-Based Classification of Flow Cytometry Samples

    Science.gov (United States)

    Azad, Ariful; Rajwa, Bartek; Pothen, Alex

    2016-01-01

    We describe algorithms for discovering immunophenotypes from large collections of flow cytometry samples and using them to organize the samples into a hierarchy based on phenotypic similarity. The hierarchical organization is helpful for effective and robust cytometry data mining, including the creation of collections of cell populations’ characteristic of different classes of samples, robust classification, and anomaly detection. We summarize a set of samples belonging to a biological class or category with a statistically derived template for the class. Whereas individual samples are represented in terms of their cell populations (clusters), a template consists of generic meta-populations (a group of homogeneous cell populations obtained from the samples in a class) that describe key phenotypes shared among all those samples. We organize an FC data collection in a hierarchical data structure that supports the identification of immunophenotypes relevant to clinical diagnosis. A robust template-based classification scheme is also developed, but our primary focus is in the discovery of phenotypic signatures and inter-sample relationships in an FC data collection. This collective analysis approach is more efficient and robust since templates describe phenotypic signatures common to cell populations in several samples while ignoring noise and small sample-specific variations. We have applied the template-based scheme to analyze several datasets, including one representing a healthy immune system and one of acute myeloid leukemia (AML) samples. The last task is challenging due to the phenotypic heterogeneity of the several subtypes of AML. However, we identified thirteen immunophenotypes corresponding to subtypes of AML and were able to distinguish acute promyelocytic leukemia (APL) samples with the markers provided. Clinically, this is helpful since APL has a different treatment regimen from other subtypes of AML. Core algorithms used in our data analysis are

  4. A special hierarchical fuzzy neural-networks based reinforcement learning for multi-variables system

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen-zhi; LU Tian-sheng

    2005-01-01

    Proposes a reinforcement learning scheme based on a special Hierarchical Fuzzy Neural-Networks (HFNN) for solving complicated learning tasks in a continuous multi-variables environment. The output of the previous layer in the HFNN is no longer used as if-part of the next layer, but used only in then-part. Thus it can deal with the difficulty when the output of the previous layer is meaningless or its meaning is uncertain. The proposed HFNN has a minimal number of fuzzy rules and can successfully solve the problem of rules combination explosion and decrease the quantity of computation and memory requirement. In the learning process, two HFNN with the same structure perform fuzzy action composition and evaluation function approximation simultaneously where the parameters of neural-networks are tuned and updated on line by using gradient descent algorithm. The reinforcement learning method is proved to be correct and feasible by simulation of a double inverted pendulum system.

  5. Photo-driven autonomous hydrogen generation system based on hierarchically shelled ZnO nanostructures

    International Nuclear Information System (INIS)

    A quantum dot semiconductor sensitized hierarchically shelled one-dimensional ZnO nanostructure has been applied as a quasi-artificial leaf for hydrogen generation. The optimized ZnO nanostructure consists of one dimensional nanowire as a core and two-dimensional nanosheet on the nanowire surface. Furthermore, the quantum dot semiconductors deposited on the ZnO nanostructures provide visible light harvesting properties. To realize the artificial leaf, we applied the ZnO based nanostructure as a photoelectrode with non-wired Z-scheme system. The demonstrated un-assisted photoelectrochemical system showed the hydrogen generation properties under 1 sun condition irradiation. In addition, the quantum dot modified photoelectrode showed 2 mA/cm2 current density at the un-assisted condition

  6. Class hierarchical test case generation algorithm based on expanded EMDPN model

    Institute of Scientific and Technical Information of China (English)

    LI Jun-yi; GONG Hong-fang; HU Ji-ping; ZOU Bei-ji; SUN Jia-guang

    2006-01-01

    A new model of event and message driven Petri network(EMDPN) based on the characteristic of class interaction for messages passing between two objects was extended. Using EMDPN interaction graph, a class hierarchical test-case generation algorithm with cooperated paths (copaths) was proposed, which can be used to solve the problems resulting from the class inheritance mechanism encountered in object-oriented software testing such as oracle, message transfer errors, and unreachable statement. Finally, the testing sufficiency was analyzed with the ordered sequence testing criterion(OSC). The results indicate that the test cases stemmed from newly proposed automatic algorithm of copaths generation satisfies synchronization message sequences testing criteria, therefore the proposed new algorithm of copaths generation has a good coverage rate.

  7. Hierarchical Pathfinding and AI-Based Learning Approach in Strategy Game Design

    Directory of Open Access Journals (Sweden)

    Le Minh Duc

    2008-01-01

    Full Text Available Strategy game and simulation application are an exciting area with many opportunities for study and research. Currently most of the existing games and simulations apply hard coded rules so the intelligence of the computer generated forces is limited. After some time, player gets used to the simulation making it less attractive and challenging. It is also costly and tedious to incorporate new rules for an existing game. The main motivation behind this research project is to improve the quality of artificial intelligence- (AI- based on various techniques such as qualitative spatial reasoning (Forbus et al., 2002, near-optimal hierarchical pathfinding (HPA* (Botea et al., 2004, and reinforcement learning (RL (Sutton and Barto, 1998.

  8. Intra-Inter Triplet Object Interaction Mechanism in Triplet-Based Hierarchical Interconnection Network

    Directory of Open Access Journals (Sweden)

    Shahnawaz Talpur

    2013-07-01

    Full Text Available Object oriented languages usually avoid direct message passing, due to its complicated implementation, though that is the promising way to communicate in concurrently inherited objects. With the advancement in the high performance computing system, interaction between parallel application objects onto physical cores becomes one of the significant issues, which is not fully explored yet. In object oriented programming attribute data is included in objects and their state can be changed using the methods. Objects enable massage passing to other objects interacting with each other. Comprehensive problems can be molded by object-oriented methodology, and solves difficult program running object-oriented programs.Cores communicate with each other through communicator and groups in MPI, but in our reference architecture TBHIN (Triplet Based Hierarchical Interconnection Network, the cores are already faction in Triplets. We propose IITOIM Model to improve the performance with efficient intra-inter triplet cores communication mechanism between the objects in TBHIN

  9. Protein structure prediction using a docking-based hierarchical folding scheme.

    Science.gov (United States)

    Kifer, Ilona; Nussinov, Ruth; Wolfson, Haim J

    2011-06-01

    The pathways by which proteins fold into their specific native structure are still an unsolved mystery. Currently, many methods for protein structure prediction are available, and most of them tackle the problem by relying on the vast amounts of data collected from known protein structures. These methods are often not concerned with the route the protein follows to reach its final fold. This work is based on the premise that proteins fold in a hierarchical manner. We present FOBIA, an automated method for predicting a protein structure. FOBIA consists of two main stages: the first finds matches between parts of the target sequence and independently folding structural units using profile-profile comparison. The second assembles these units into a 3D structure by searching and ranking their possible orientations toward each other using a docking-based approach. We have previously reported an application of an initial version of this strategy to homology based targets. Since then we have considerably enhanced our method's abilities to allow it to address the more difficult template-based target category. This allows us to now apply FOBIA to the template-based targets of CASP8 and to show that it is both very efficient and promising. Our method can provide an alternative for template-based structure prediction, and in particular, the docking-basedranking technique presented here can be incorporated into any profile-profile comparison based method. PMID:21445943

  10. Flexible free-standing luminescent two-component fiber films with tunable hierarchical structures based on hydrogen-bonding architecture.

    Science.gov (United States)

    Yan, Dongpeng; Williams, Gareth R; Zhao, Min; Li, Changming; Fan, Guoling; Yang, Hejia

    2013-12-17

    Although the fabrication of hierarchical architectures with highly ordered functional units is of great importance for both fundamental science and practical application, the development of one-dimensional (1D) organic hierarchical micro/nanostructures based on low-molecular-weight (LMW) building blocks remains at an early stage. Herein, we report two types of micro/nanoscaled multicomponent fluorescent fiber systems with tunable hierarchical morphologies through a one-step coassembly process. With the aid of hydrogen-bonding motifs, LMW precursors (1,4-bis(5-phenyloxazol-2-yl)benzene (A) and two coassembled building blocks: 4-bromotetrafluorobenzene carboxylic acid (B) and 2,3,4,5,6-pentafluorophenol (C)) have been self-organized into fibers and flexible free-standing films, which show hierarchical micro/nanostructures as well as tunable one-/two-photon luminescence. The disassembly of the multicomponent A.B and A.C fibers occurs at high temperature, which further alters the luminescence properties of the multicomponent materials. Therefore, this work provides a facile wet chemical route for fabricating multicomponent LMW self-assembled fibers and free-standing film systems with tunable hierarchical structures and photoemission behaviors, and such self-organized systems may have potential applications in fields of two-photon luminescence and thermal sensors. PMID:24274340

  11. Hierarchical construction of PbS architectures based on the adsorption and sustained release of H2S by TBAB

    International Nuclear Information System (INIS)

    Graphical abstract: PbS uniform hierarchical microstars were grown on a large scale by a simple hydrothermal method with the help of a new surfactant: tetrabutyl ammonium bromide (C16H36BrN). A possible new formation mechanism of hierarchical hollow PbS structures based on the adsorption and sustained release of S2+ by TBAB is presented. Highlights: → Multi-arm PbS hierarchical structures were successfully synthesized by a simple hydrothermal method at low temperature: 90 deg. C. → A new surfactant: tetrabutyl ammonium bromide (TBAB) was used in the process, a possible new formation mechanism of hierarchical hollow PbS structures based on the adsorption and sustained release of S2+ by TBAB is presented. - Abstract: Multi-arm PbS architectures were successfully synthesized in high yield by a facile hydrothermal process at 90 deg. C for 48 h, employing lead nitrate (Pb(NO3)2) and thioacetamide (TAA) as precursors. A new surfactant: tetrabutyl ammonium bromide (TBAB), was used in this process. The as-prepared PbS products are characterized by X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and Fourier transform infrared (FT-IR) spectroscopy. The results showed that the concentration of TBAB, as well as the molar ratio of Pb(NO3)2 to TAA are crucial factors on the morphologies and sizes of the hierarchical PbS microcrystals. A reasonable possible new formation mechanism of hierarchical PbS structures based on the adsorption and sustained release of H2S by TBAB has been presented.

  12. Single Vs Hierarchical Population-Based Memetic Algorithm for Sat-Encoded Industrial Problems:A Statistical Comparison

    Directory of Open Access Journals (Sweden)

    Noureddine Bouhmala

    2012-12-01

    Full Text Available In this work, a hierarchical population-based memetic algorithm for solving the satisfiability problem ispresented. The approach suggests looking at the evolution as a hierarchical process evolving from a coarsepopulation where the basic unit of a gene is composed of cluster of variables that represent the problem toa fine population where each gene represents a single variable. The optimization process is carried out byletting the converged population at a child level serve as the initial population to the parent level. Abenchmark composed of industrial instances is used to compare the effectiveness of the hierarchicalapproach against its single-level counterpart.

  13. Road centerline extraction from airborne LiDAR point cloud based on hierarchical fusion and optimization

    Science.gov (United States)

    Hui, Zhenyang; Hu, Youjian; Jin, Shuanggen; Yevenyo, Yao Ziggah

    2016-08-01

    Road information acquisition is an important part of city informatization construction. Airborne LiDAR provides a new means of acquiring road information. However, the existing road extraction methods using LiDAR point clouds always decide the road intensity threshold based on experience, which cannot obtain the optimal threshold to extract a road point cloud. Moreover, these existing methods are deficient in removing the interference of narrow roads and several attached areas (e.g., parking lot and bare ground) to main roads extraction, thereby imparting low completeness and correctness to the city road network extraction result. Aiming at resolving the key technical issues of road extraction from airborne LiDAR point clouds, this paper proposes a novel method to extract road centerlines from airborne LiDAR point clouds. The proposed approach is mainly composed of three key algorithms, namely, Skewness balancing, Rotating neighborhood, and Hierarchical fusion and optimization (SRH). The skewness balancing algorithm used for the filtering was adopted as a new method for obtaining an optimal intensity threshold such that the "pure" road point cloud can be obtained. The rotating neighborhood algorithm on the other hand was developed to remove narrow roads (corridors leading to parking lots or sidewalks), which are not the main roads to be extracted. The proposed hierarchical fusion and optimization algorithm caused the road centerlines to be unaffected by certain attached areas and ensured the road integrity as much as possible. The proposed method was tested using the Vaihingen dataset. The results demonstrated that the proposed method can effectively extract road centerlines in a complex urban environment with 91.4% correctness and 80.4% completeness.

  14. Iris Recognition Using Modified Hierarchical Phase-Based Matching (HPM Technique

    Directory of Open Access Journals (Sweden)

    C.Anand Deva Durai

    2010-05-01

    Full Text Available This paper explores an efficient algorithm for iris recognition based on Hierarchical Phase-Based Image Matching (HPM technique. One of the difficult problems in feature-based iris recognition is that the matching performance is significantly influenced by many parameters in feature extraction process, which may vary depending on environmental factors of image acquisition. The proposed system is designed for applications where the training database contains an iris for each individual. The final decision is made by HPM at "matching score level architecture" in which feature vectors are created independently for query images and are then compared to the enrollment templates which are stored during database preparation for each biometric trait. Based on the proximity of feature vector and template, each subsystem computes its own matching score. These individual scores are finally combined into a total score, which is passed to the decision module. In this proposed technique, the use of phase components in 2D (two dimensional discrete Fourier transforms of iris images makes possible to achieve highly robust iris recognition in a unified fashion with a simple matching algorithm. The technique has been successfully applied and also clearly demonstrates an efficient matching performance of the proposed algorithm.

  15. 3D CAD model retrieval method based on hierarchical multi-features

    Science.gov (United States)

    An, Ran; Wang, Qingwen

    2015-12-01

    The classical "Shape Distribution D2" algorithm takes the distance between two random points on a surface of CAD model as statistical features, and based on that it generates a feature vector to calculate the dissimilarity and achieve the retrieval goal. This algorithm has a simple principle, high computational efficiency and can get a better retrieval results for the simple shape models. Based on the analysis of D2 algorithm's shape distribution curve, this paper enhances the algorithm's descriptive ability for a model's overall shape through the statistics of the angle between two random points' normal vectors, especially for the distinctions between the model's plane features and curved surface features; meanwhile, introduce the ratio that a line between two random points cut off by the model's surface to enhance the algorithm's descriptive ability for a model's detailed features; finally, integrating the two shape describing methods with the original D2 algorithm, this paper proposes a new method based the hierarchical multi-features. Experimental results showed that this method has bigger improvements and could get a better retrieval results compared with the traditional 3D CAD model retrieval method.

  16. Nhs: Network-based Hierarchical Segmentation for Cryo-EM Density Maps

    Science.gov (United States)

    Burger, Virginia; Chennubhotla, Chakra

    2012-01-01

    Electron cryo-microscopy (cryo-EM) experiments yield low-resolution (3–30Å) 3D-density maps of macromolecules. These density maps are segmented to identify structurally distinct proteins, protein domains, and sub-units. Such partitioning aids the inference of protein motions and guides fitting of high-resolution atomistic structures. Cryo-EM density map segmentation has traditionally required tedious and subjective manual partitioning or semi-supervised computational methods, while validation of resulting segmentations has remained an open problem in this field. Our network-based bias-free segmentation method for cryo-EM density map segmentation, Nhs (Network-based hierarchical segmentation), provides the user with a multi-scale partitioning, reflecting local and global clustering, while requiring no user input. This approach models each map as a graph, where map voxels constitute nodes and edges connect neighboring voxels. Nhs initiates Markov diffusion (or random walk) on the weighted graph. As Markov probabilities homogenize through diffusion, an intrinsic segmentation emerges. We validate the segmentations with ground-truth maps based on atomistic models. When implemented on density maps in the 2010 Cryo-EM Modeling Challenge, Nhs efficiently and objectively partitions macromolecules into structurally and functionally relevant sub-regions at multiple scales. PMID:22696408

  17. Constructing a raster-based spatio-temporal hierarchical data model for marine fisheries application

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Marine information has been increasing quickly. The traditional database technologies have disadvantages in manipulating large amounts of marine information which relates to the position in 3-D with the time. Recently, greater emphasis has been placed on GIS (geographical information system)to deal with the marine information. The GIS has shown great success for terrestrial applications in the last decades, but its use in marine fields has been far more restricted. One of the main reasons is that most of the GIS systems or their data models are designed for land applications. They cannot do well with the nature of the marine environment and for the marine information. And this becomes a fundamental challenge to the traditional GIS and its data structure. This work designed a data model,the raster-based spatio-temporal hierarchical data model (RSHDM), for the marine information system, or for the knowledge discovery from spatio-temporal data, which bases itself on the nature of the marine data and overcomes the shortages of the current spatio-temporal models when they are used in the field. As an experiment, the marine fishery data warehouse (FDW) for marine fishery management was set up, which was based on the RSHDM. The experiment proved that the RSHDM can do well with the data and can extract easily the aggregations that the management needs at different levels.

  18. MAP-Based Underdetermined Blind Source Separation of Convolutive Mixtures by Hierarchical Clustering and -Norm Minimization

    Directory of Open Access Journals (Sweden)

    Kellermann Walter

    2007-01-01

    Full Text Available We address the problem of underdetermined BSS. While most previous approaches are designed for instantaneous mixtures, we propose a time-frequency-domain algorithm for convolutive mixtures. We adopt a two-step method based on a general maximum a posteriori (MAP approach. In the first step, we estimate the mixing matrix based on hierarchical clustering, assuming that the source signals are sufficiently sparse. The algorithm works directly on the complex-valued data in the time-frequency domain and shows better convergence than algorithms based on self-organizing maps. The assumption of Laplacian priors for the source signals in the second step leads to an algorithm for estimating the source signals. It involves the -norm minimization of complex numbers because of the use of the time-frequency-domain approach. We compare a combinatorial approach initially designed for real numbers with a second-order cone programming (SOCP approach designed for complex numbers. We found that although the former approach is not theoretically justified for complex numbers, its results are comparable to, or even better than, the SOCP solution. The advantage is a lower computational cost for problems with low input/output dimensions.

  19. Fabrication of semi-transparent super-hydrophobic surface based on silica hierarchical structures

    International Nuclear Information System (INIS)

    This study successfully develops a versatile method of producing superhydrophobic surfaces with micro/nano-silica hierarchical structures on glass surfaces. Optically transparent super hydrophobic silica thin films were prepared by spin-coating silica particles suspended in a precursor solution of silane, ethanol, and H2O with molar ratio of 1:4:4. The resulting super hydrophobic films were characterized by scanning electron microscopy (SEM), optical transmission, and contact angle measurements. The glass substrates in this study were modified with different particles: micro-silica particles, nano-silica particles, and hierarchical structures. This study includes SEM micrographs of the modified glass surfaces with hierarchical structures at different magnifications

  20. Analysis of the twin spacing and grain size effects on mechanical properties in hierarchically nanotwinned face-centered cubic metals based on a mechanism-based plasticity model

    Science.gov (United States)

    Zhu, Linli; Qu, Shaoxing; Guo, Xiang; Lu, Jian

    2015-03-01

    Hierarchical twin lamellae in polycrystalline face-centered cubic (fcc) metals possess a possibility to achieve higher strength with keeping an acceptable elongation. The present work is concerned with the analysis of twin spacing and grain size-dependent plastic performance in hierarchically nanotwinned fcc metals using a generalized strain-gradient plasticity model. The dislocation density-based physical model for constitutive description of nanotwinned fcc metals is expanded for the hierarchical structures of nanotwins. The strengthening mechanism and the failure behavior in these hierarchical nanostructures are studied to evaluate the strength and ductility. Moreover, the transition twin spacing between the strengthening and softening is obtained in different order of twin lamellae. A dislocation-based model on nucleating deformation twins is presented to predict the critical twin spacing in the lowest twin lamellae for generating the subordinate twin lamellae. Our simulation results demonstrate that the existence of the hierarchical nanotwins gives rise to a significant enhancement in the strength, and the resulting global flow stresses are sensitive to the twin spacings of the hierarchical twin lamellae and the grain size. Two softening stages are observed with variation of twin spacing, and the relevant transition twin spacing depends on the microstructural size in hierarchically nanotwinned metals. We further find that the predicted failure strain decreases with decreasing the twin spacing, which is quite different from the case of the individually nanotwinned fcc metals. The critical twin spacing for generating subordinate twins also depends on the twin spacing of superordinate twin lamellae and the grain size. These findings suggest that the high yield strength and good ductility can be achieved by optimizing the grain size and the twin spacings in the hierarchical twins.

  1. Intelligent multiagent coordination based on reinforcement hierarchical neuro-fuzzy models.

    Science.gov (United States)

    Mendoza, Leonardo Forero; Vellasco, Marley; Figueiredo, Karla

    2014-12-01

    This paper presents the research and development of two hybrid neuro-fuzzy models for the hierarchical coordination of multiple intelligent agents. The main objective of the models is to have multiple agents interact intelligently with each other in complex systems. We developed two new models of coordination for intelligent multiagent systems, which integrates the Reinforcement Learning Hierarchical Neuro-Fuzzy model with two proposed coordination mechanisms: the MultiAgent Reinforcement Learning Hierarchical Neuro-Fuzzy with a market-driven coordination mechanism (MA-RL-HNFP-MD) and the MultiAgent Reinforcement Learning Hierarchical Neuro-Fuzzy with graph coordination (MA-RL-HNFP-CG). In order to evaluate the proposed models and verify the contribution of the proposed coordination mechanisms, two multiagent benchmark applications were developed: the pursuit game and the robot soccer simulation. The results obtained demonstrated that the proposed coordination mechanisms greatly improve the performance of the multiagent system when compared with other strategies. PMID:25406641

  2. A hierarchical algorithm for cyberspace situational awareness based on analytic hierarchy process

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The existing network security management systems are unable either to provide users with useful security situation and risk assessment, or to aid administrators to make right and timely decisions based on the current state of network. These disadvantages always put the whole network security management at high risk. This paper establishes a simulation environment, captures the alerts as the experimental data and adopts statistical analysis to seek the vulnerabilities of the services provided by the hosts in the network. According to the factors of the network, the paper introduces the two concepts: Situational Meta and Situational Weight to depict the total security situation. A novel hierarchical algorithm based on analytic hierarchy process (AHP) is proposed to analyze the hierarchy of network and confirm the weighting coefficients. The algorithm can be utilized for modeling security situation, and determining its mathematical expression. Coupled with the statistical results, this paper simulates the security situational trends.Finally, the analysis of the simulation results proves the algorithm efficient and applicable, and provides us with an academic foundation for the implementation in the security situation.

  3. A hierarchical model for structure learning based on the physiological characteristics of neurons

    Institute of Scientific and Technical Information of China (English)

    WEI Hui

    2007-01-01

    Almost all applications of Artificial Neural Networks (ANNs) depend mainly on their memory ability.The characteristics of typical ANN models are fixed connections,with evolved weights,globalized representations,and globalized optimizations,all based on a mathematical approach.This makes those models to be deficient in robustness,efficiency of learning,capacity,anti-jamming between training sets,and correlativity of samples,etc.In this paper,we attempt to address these problems by adopting the characteristics of biological neurons in morphology and signal processing.A hierarchical neural network was designed and realized to implement structure learning and representations based on connected structures.The basic characteristics of this model are localized and random connections,field limitations of neuron fan-in and fan-out,dynamic behavior of neurons,and samples represented through different sub-circuits of neurons specialized into different response patterns.At the end of this paper,some important aspects of error correction,capacity,learning efficiency,and soundness of structural representation are analyzed theoretically.This paper has demonstrated the feasibility and advantages of structure learning and representation.This model can serve as a fundamental element of cognitive systems such as perception and associative memory.Key-words structure learning,representation,associative memory,computational neuroscience

  4. An Integrated Model Based on a Hierarchical Indices System for Monitoring and Evaluating Urban Sustainability

    Directory of Open Access Journals (Sweden)

    Xulin Guo

    2013-02-01

    Full Text Available Over 50% of world’s population presently resides in cities, and this number is expected to rise to ~70% by 2050. Increasing urbanization problems including population growth, urban sprawl, land use change, unemployment, and environmental degradation, have markedly impacted urban residents’ Quality of Life (QOL. Therefore, urban sustainability and its measurement have gained increasing attention from administrators, urban planners, and scientific communities throughout the world with respect to improving urban development and human well-being. The widely accepted definition of urban sustainability emphasizes the balancing development of three primary domains (urban economy, society, and environment. This article attempts to improve the aforementioned definition of urban sustainability by incorporating a human well-being dimension. Major problems identified in existing urban sustainability indicator (USI models include a weak integration of potential indicators, poor measurement and quantification, and insufficient spatial-temporal analysis. To tackle these challenges an integrated USI model based on a hierarchical indices system was established for monitoring and evaluating urban sustainability. This model can be performed by quantifying indicators using both traditional statistical approaches and advanced geomatic techniques based on satellite imagery and census data, which aims to provide a theoretical basis for a comprehensive assessment of urban sustainability from a spatial-temporal perspective.

  5. Humic acids-based hierarchical porous carbons as high-rate performance electrodes for symmetric supercapacitors.

    Science.gov (United States)

    Qiao, Zhi-jun; Chen, Ming-ming; Wang, Cheng-yang; Yuan, Yun-cai

    2014-07-01

    Two kinds of hierarchical porous carbons (HPCs) with specific surface areas of 2000 m(2)g(-1) were synthesized using leonardite humic acids (LHA) or biotechnology humic acids (BHA) precursors via a KOH activation process. Humic acids have a high content of oxygen-containing groups which enabled them to dissolve in aqueous KOH and facilitated the homogeneous KOH activation. The LHA-based HPC is made up of abundant micro-, meso-, and macropores and in 6M KOH it has a specific capacitance of 178 F g(-1) at 100 Ag(-1) and its capacitance retention on going from 0.05 to 100 A g(-1) is 64%. In contrast, the BHA-based HPC exhibits a lower capacitance retention of 54% and a specific capacitance of 157 F g(-1) at 100 A g(-1) which is due to the excessive micropores in the BHA-HPC. Moreover, LHA-HPC is produced in a higher yield than BHA-HPC (51 vs. 17 wt%). PMID:24851713

  6. Enhancing the Discrete Particle Swarm Optimization based Workflow Grid Scheduling using Hierarchical Structure

    Directory of Open Access Journals (Sweden)

    Ritu Garg

    2013-05-01

    Full Text Available The problem of scheduling dependent tasks (DAG is an important version of scheduling, to efficiently exploit the computational capabilities of grid systems. The problem of scheduling tasks of a graph onto a set of different machines is an NP Complete problem. As a result, a number of heuristic and meta-heuristic approaches are used over the years due to their ability of providing high quality solutions with reasonable computation time. Discrete Particle Swarm Optimization is one such meta-heuristic used for solving the discrete problem of grid scheduling, but this method converge to sub optimal solutions due to premature convergence. To deal with premature convergence, in this paper we proposed the design and implementation of hierarchical discrete particle swarm optimization (H-DPSO for dependent task scheduling in grid environment. In H-DPSO particles are arranged in dynamic hierarchy where good particles lying above in hierarchy are having larger influence on the swarm. We consider the bi-objective version of problem to minimize makespan and total cost simultaneously as the optimization criteria. The H-DPSO based scheduler was evaluated under different application task graphs. Simulation analysis manifests that H-DPSO based scheduling is highly viable and effective approach for grid computing.

  7. Hierarchical Clustering Algorithm based on Attribute Dependency for Attention Deficit Hyperactive Disorder

    Directory of Open Access Journals (Sweden)

    J Anuradha

    2014-05-01

    Full Text Available Attention Deficit Hyperactive Disorder (ADHD is a disruptive neurobehavioral disorder characterized by abnormal behavioral patterns in attention, perusing activity, acting impulsively and combined types. It is predominant among school going children and it is tricky to differentiate between an active and an ADHD child. Misdiagnosis and undiagnosed cases are very common. Behavior patterns are identified by the mentors in the academic environment who lack skills in screening those kids. Hence an unsupervised learning algorithm can cluster the behavioral patterns of children at school for diagnosis of ADHD. In this paper, we propose a hierarchical clustering algorithm to partition the dataset based on attribute dependency (HCAD. HCAD forms clusters of data based on the high dependent attributes and their equivalence relation. It is capable of handling large volumes of data with reasonably faster clustering than most of the existing algorithms. It can work on both labeled and unlabelled data sets. Experimental results reveal that this algorithm has higher accuracy in comparison to other algorithms. HCAD achieves 97% of cluster purity in diagnosing ADHD. Empirical analysis of application of HCAD on different data sets from UCI repository is provided.

  8. Dynamic and Quantitative Method of Analyzing Service Consistency Evolution Based on Extended Hierarchical Finite State Automata

    Directory of Open Access Journals (Sweden)

    Linjun Fan

    2014-01-01

    Full Text Available This paper is concerned with the dynamic evolution analysis and quantitative measurement of primary factors that cause service inconsistency in service-oriented distributed simulation applications (SODSA. Traditional methods are mostly qualitative and empirical, and they do not consider the dynamic disturbances among factors in service’s evolution behaviors such as producing, publishing, calling, and maintenance. Moreover, SODSA are rapidly evolving in terms of large-scale, reusable, compositional, pervasive, and flexible features, which presents difficulties in the usage of traditional analysis methods. To resolve these problems, a novel dynamic evolution model extended hierarchical service-finite state automata (EHS-FSA is constructed based on finite state automata (FSA, which formally depict overall changing processes of service consistency states. And also the service consistency evolution algorithms (SCEAs based on EHS-FSA are developed to quantitatively assess these impact factors. Experimental results show that the bad reusability (17.93% on average is the biggest influential factor, the noncomposition of atomic services (13.12% is the second biggest one, and the service version’s confusion (1.2% is the smallest one. Compared with previous qualitative analysis, SCEAs present good effectiveness and feasibility. This research can guide the engineers of service consistency technologies toward obtaining a higher level of consistency in SODSA.

  9. Hierarchical structure of the European countries based on debts as a percentage of GDP during the 2000-2011 period

    Science.gov (United States)

    Kantar, Ersin; Deviren, Bayram; Keskin, Mustafa

    2014-11-01

    We investigate hierarchical structures of the European countries by using debt as a percentage of Gross Domestic Product (GDP) of the countries as they change over a certain period of time. We obtain the topological properties among the countries based on debt as a percentage of GDP of European countries over the period 2000-2011 by using the concept of hierarchical structure methods (minimal spanning tree, (MST) and hierarchical tree, (HT)). This period is also divided into two sub-periods related to 2004 enlargement of the European Union, namely 2000-2004 and 2005-2011, in order to test various time-window and observe the temporal evolution. The bootstrap techniques is applied to see a value of statistical reliability of the links of the MSTs and HTs. The clustering linkage procedure is also used to observe the cluster structure more clearly. From the structural topologies of these trees, we identify different clusters of countries according to their level of debts. Our results show that by the debt crisis, the less and most affected Eurozone’s economies are formed as a cluster with each other in the MSTs and hierarchical trees.

  10. Identifying hierarchical and overlapping protein complexes based on essential protein-protein interactions and "seed-expanding" method.

    Science.gov (United States)

    Ren, Jun; Zhou, Wei; Wang, Jianxin

    2014-01-01

    Many evidences have demonstrated that protein complexes are overlapping and hierarchically organized in PPI networks. Meanwhile, the large size of PPI network wants complex detection methods have low time complexity. Up to now, few methods can identify overlapping and hierarchical protein complexes in a PPI network quickly. In this paper, a novel method, called MCSE, is proposed based on λ-module and "seed-expanding." First, it chooses seeds as essential PPIs or edges with high edge clustering values. Then, it identifies protein complexes by expanding each seed to a λ-module. MCSE is suitable for large PPI networks because of its low time complexity. MCSE can identify overlapping protein complexes naturally because a protein can be visited by different seeds. MCSE uses the parameter λ_th to control the range of seed expanding and can detect a hierarchical organization of protein complexes by tuning the value of λ_th. Experimental results of S. cerevisiae show that this hierarchical organization is similar to that of known complexes in MIPS database. The experimental results also show that MCSE outperforms other previous competing algorithms, such as CPM, CMC, Core-Attachment, Dpclus, HC-PIN, MCL, and NFC, in terms of the functional enrichment and matching with known protein complexes. PMID:25143945

  11. Identifying Hierarchical and Overlapping Protein Complexes Based on Essential Protein-Protein Interactions and “Seed-Expanding” Method

    Directory of Open Access Journals (Sweden)

    Jun Ren

    2014-01-01

    Full Text Available Many evidences have demonstrated that protein complexes are overlapping and hierarchically organized in PPI networks. Meanwhile, the large size of PPI network wants complex detection methods have low time complexity. Up to now, few methods can identify overlapping and hierarchical protein complexes in a PPI network quickly. In this paper, a novel method, called MCSE, is proposed based on λ-module and “seed-expanding.” First, it chooses seeds as essential PPIs or edges with high edge clustering values. Then, it identifies protein complexes by expanding each seed to a λ-module. MCSE is suitable for large PPI networks because of its low time complexity. MCSE can identify overlapping protein complexes naturally because a protein can be visited by different seeds. MCSE uses the parameter λ_th to control the range of seed expanding and can detect a hierarchical organization of protein complexes by tuning the value of λ_th. Experimental results of S. cerevisiae show that this hierarchical organization is similar to that of known complexes in MIPS database. The experimental results also show that MCSE outperforms other previous competing algorithms, such as CPM, CMC, Core-Attachment, Dpclus, HC-PIN, MCL, and NFC, in terms of the functional enrichment and matching with known protein complexes.

  12. Identifying Hierarchical and Overlapping Protein Complexes Based on Essential Protein-Protein Interactions and “Seed-Expanding” Method

    Science.gov (United States)

    Ren, Jun; Zhou, Wei; Wang, Jianxin

    2014-01-01

    Many evidences have demonstrated that protein complexes are overlapping and hierarchically organized in PPI networks. Meanwhile, the large size of PPI network wants complex detection methods have low time complexity. Up to now, few methods can identify overlapping and hierarchical protein complexes in a PPI network quickly. In this paper, a novel method, called MCSE, is proposed based on λ-module and “seed-expanding.” First, it chooses seeds as essential PPIs or edges with high edge clustering values. Then, it identifies protein complexes by expanding each seed to a λ-module. MCSE is suitable for large PPI networks because of its low time complexity. MCSE can identify overlapping protein complexes naturally because a protein can be visited by different seeds. MCSE uses the parameter λ_th to control the range of seed expanding and can detect a hierarchical organization of protein complexes by tuning the value of λ_th. Experimental results of S. cerevisiae show that this hierarchical organization is similar to that of known complexes in MIPS database. The experimental results also show that MCSE outperforms other previous competing algorithms, such as CPM, CMC, Core-Attachment, Dpclus, HC-PIN, MCL, and NFC, in terms of the functional enrichment and matching with known protein complexes. PMID:25143945

  13. Hierarchical design of an electro-hydraulic actuator based on robust LPV methods

    Science.gov (United States)

    Németh, Balázs; Varga, Balázs; Gáspár, Péter

    2015-08-01

    The paper proposes a hierarchical control design of an electro-hydraulic actuator, which is used to improve the roll stability of vehicles. The purpose of the control system is to generate a reference torque, which is required by the vehicle dynamic control. The control-oriented model of the actuator is formulated in two subsystems. The high-level hydromotor is described in a linear form, while the low-level spool valve is a polynomial system. These subsystems require different control strategies. At the high level, a linear parameter-varying control is used to guarantee performance specifications. At the low level, a control Lyapunov-function-based algorithm, which creates discrete control input values of the valve, is proposed. The interaction between the two subsystems is guaranteed by the spool displacement, which is control input at the high level and must be tracked at the low-level control. The spool displacement has physical constraints, which must also be incorporated into the control design. The robust design of the high-level control incorporates the imprecision of the low-level control as an uncertainty of the system.

  14. AERODYNAMIC OPTIMIZATION FOR TURBINE BLADE BASED ON HIERARCHICAL FAIR COMPETITION GENETIC ALGORITHMS WITH DYNAMIC NICHE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A global optimization approach to turbine blade design based on hierarchical fair competition genetic algorithms with dynamic niche (HFCDN-GAs) coupled with Reynolds-averaged Navier-Stokes (RANS) equation is presented. In order to meet the search theory of GAs and the aerodynamic performances of turbine, Bezier curve is adopted to parameterize the turbine blade profile, and a fitness function pertaining to optimization is designed. The design variables are the control points' ordinates of characteristic polygon of Bezier curve representing the turbine blade profile. The object function is the maximum lift-drag ratio of the turbine blade. The constraint conditions take into account the leading and trailing edge metal angle, and the strength and aerodynamic performances of turbine blade. And the treatment method of the constraint conditions is the flexible penalty function. The convergence history of test function indicates that HFCDN-GAs can locate the global optimum within a few search steps and have high robustness. The lift-drag ratio of the optimized blade is 8.3% higher than that of the original one. The results show that the proposed global optimization approach is effective for turbine blade.

  15. Mobile Agent Based Hierarchical Intrusion Detection System in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Surraya Khanum

    2012-01-01

    Full Text Available Security mechanism is a fundamental requirement of wireless networks in general and Wireless Sensor Networks (WSN in particular. Therefore, it is necessary that this security concern must be articulate right from the beginning of the network design and deployment. WSN needs strong security mechanism as it is usually deployed in a critical, hostile and sensitive environment where human labour is usually not involved. However, due to inbuilt resource and computing restriction, security in WSN needs a special consideration. Traditional security techniques such as encryption, VPN, authentication and firewalls cannot be directly applied to WSN as it provides defence only against external threats. The existing literature shows that there seems an inverse relationship between strong security mechanism and efficient network resource utilization. In this research article, we have proposed a Mobile Agent Based Hierarchical Intrusion Detection System (MABHIDS for WSN. The Proposed scheme performs two levels of intrusion detection by utilizing minimum possible network resources. Our proposed idea enhance network lifetime by reducing the work load on Cluster Head (CH and it also provide enhanced level of security in WSN.

  16. A new Hierarchical Group Key Management based on Clustering Scheme for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Ayman EL-SAYED

    2014-05-01

    Full Text Available The migration from wired network to wireless network has been a global trend in the past few decades because they provide anytime-anywhere networking services. The wireless networks are rapidly deployed in the future, secure wireless environment will be mandatory. As well, The mobility and scalability brought by wireless network made it possible in many applications. Among all the contemporary wireless networks,Mobile Ad hoc Networks (MANET is one of the most important and unique applications. MANET is a collection of autonomous nodes or terminals which communicate with each other by forming a multihop radio network and maintaining connectivity in a decentralized manner. Due to the nature of unreliable wireless medium data transfer is a major problem in MANET and it lacks security and reliability of data. The most suitable solution to provide the expected level of security to these services is the provision of a key management protocol. A Key management is vital part of security. This issue is even bigger in wireless network compared to wired network. The distribution of keys in an authenticated manner is a difficult task in MANET. When a member leaves or joins the group, it needs to generate a new key to maintain forward and backward secrecy. In this paper, we propose a new group key management schemes namely a Hierarchical, Simple, Efficient and Scalable Group Key (HSESGK based on clustering management scheme for MANETs and different other schemes are classified. Group members deduce the group key in a distributed manner.

  17. Hierarchical Control Scheme for Improving Transient Voltage Recovery of a DFIG-Based WPP

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinho; Muljadi, Eduard; Kang, Yong Cheol

    2015-06-05

    Modern grid codes require that wind power plants (WPPs) inject reactive power according to the voltage dip at a point of interconnection (POI). This requirement helps to support a POI voltage during a fault. However, if a fault is cleared, the POI and wind turbine generator (WTG) voltages are likely to exceed acceptable levels unless the WPP reduces the injected reactive power quickly. This might deteriorate the stability of a grid by allowing the disconnection of WTGs to avoid any damage. This paper proposes a hierarchical control scheme of a doubly-fed induction generator (DFIG)-based WPP. The proposed scheme aims to improve the reactive power injecting capability during the fault and suppress the overvoltage after the fault clearance. To achieve the former, an adaptive reactive power-to-voltage scheme is implemented in each DFIG controller so that a DFIG with a larger reactive power capability will inject more reactive power. To achieve the latter, a washout filter is used to capture a high frequency component contained in the WPP voltage, which is used to remove the accumulated values in the proportional-integral controllers. Test results indicate that the scheme successfully supports the grid voltage during the fault, and recovers WPP voltages without exceeding the limit after the fault clearance.

  18. Robust Face Recognition by Hierarchical Kernel Associative Memory Models Based on Spatial Domain Gabor Transforms

    Directory of Open Access Journals (Sweden)

    Bai-ling Zhang

    2006-07-01

    Full Text Available Face recognition can be studied as an associative memory (AM problem and kernel-based AM models have been proven efficient. In this paper, a hierarchical Kernel Associative Memory (KAM face recognition scheme with a multiscale Gabor transform, is proposed. The pyramidal multiscale Gabor decomposition proposed by Nestares, Navarro, Portilla and Tabernero not only provides a very efficient implementation of the Gabor transform in the spatial domain, but also permits a fast reconstruction of images. In our method, face images of each person are first decomposed into their multiscale representations by a quasicomplete Gabor transform, which are then modelled by Kernel Associative Memories. In the recognition stage, a query face image is also represented by a Gabor multiresolution pyramid and the reconstructions from different KAM models corresponding to even Gabor channels are then simply summed to give the recall. The recognition scheme was thoroughly tested using several benchmarking face datasets, including the AR faces, UMIST faces, JAFFE faces and Yale A faces, which include different kind of face variations from occlusions, pose, expression and illumination. The experiment results show that the proposed method demonstrated strong robustness in recognizing faces under different conditions, particularly under occlusions, pose alterations and expression changes.

  19. Prolonging the lifetime of wireless sensor networks interconnected to fixed network using hierarchical energy tree based routing algorithm.

    Science.gov (United States)

    Kalpana, M; Dhanalakshmi, R; Parthiban, P

    2014-01-01

    This research work proposes a mathematical model for the lifetime of wireless sensor networks (WSN). It also proposes an energy efficient routing algorithm for WSN called hierarchical energy tree based routing algorithm (HETRA) based on hierarchical energy tree constructed using the available energy in each node. The energy efficiency is further augmented by reducing the packet drops using exponential congestion control algorithm (TCP/EXP). The algorithms are evaluated in WSNs interconnected to fixed network with seven distribution patterns, simulated in ns2 and compared with the existing algorithms based on the parameters such as number of data packets, throughput, network lifetime, and data packets average network lifetime product. Evaluation and simulation results show that the combination of HETRA and TCP/EXP maximizes longer network lifetime in all the patterns. The lifetime of the network with HETRA algorithm has increased approximately 3.2 times that of the network implemented with AODV. PMID:25535626

  20. A Medical Cloud-Based Platform for Respiration Rate Measurement and Hierarchical Classification of Breath Disorders

    Directory of Open Access Journals (Sweden)

    Atena Roshan Fekr

    2014-06-01

    Full Text Available The measurement of human respiratory signals is crucial in cyberbiological systems. A disordered breathing pattern can be the first symptom of different physiological, mechanical, or psychological dysfunctions. Therefore, a real-time monitoring of the respiration patterns, as well as respiration rate is a critical need in medical applications. There are several methods for respiration rate measurement. However, despite their accuracy, these methods are expensive and could not be integrated in a body sensor network. In this work, we present a real-time cloud-based platform for both monitoring the respiration rate and breath pattern classification, remotely. The proposed system is designed particularly for patients with breathing problems (e.g., respiratory complications after surgery or sleep disorders. Our system includes calibrated accelerometer sensor, Bluetooth Low Energy (BLE and cloud-computing model. We also suggest a procedure to improve the accuracy of respiration rate for patients at rest positions. The overall error in the respiration rate calculation is obtained 0.53% considering SPR-BTA spirometer as the reference. Five types of respiration disorders, Bradapnea, Tachypnea, Cheyn-stokes, Kaussmal, and Biot’s breathing are classified based on hierarchical Support Vector Machine (SVM with seven different features. We have evaluated the performance of the proposed classification while it is individualized to every subject (case 1 as well as considering all subjects (case 2. Since the selection of kernel function is a key factor to decide SVM’s performance, in this paper three different kernel functions are evaluated. The experiments are conducted with 11 subjects and the average accuracy of 94.52% for case 1 and the accuracy of 81.29% for case 2 are achieved based on Radial Basis Function (RBF. Finally, a performance evaluation has been done for normal and impaired subjects considering sensitivity, specificity and G-mean parameters

  1. A medical cloud-based platform for respiration rate measurement and hierarchical classification of breath disorders.

    Science.gov (United States)

    Fekr, Atena Roshan; Janidarmian, Majid; Radecka, Katarzyna; Zilic, Zeljko

    2014-01-01

    The measurement of human respiratory signals is crucial in cyberbiological systems. A disordered breathing pattern can be the first symptom of different physiological, mechanical, or psychological dysfunctions. Therefore, a real-time monitoring of the respiration patterns, as well as respiration rate is a critical need in medical applications. There are several methods for respiration rate measurement. However, despite their accuracy, these methods are expensive and could not be integrated in a body sensor network. In this work, we present a real-time cloud-based platform for both monitoring the respiration rate and breath pattern classification, remotely. The proposed system is designed particularly for patients with breathing problems (e.g., respiratory complications after surgery) or sleep disorders. Our system includes calibrated accelerometer sensor, Bluetooth Low Energy (BLE) and cloud-computing model. We also suggest a procedure to improve the accuracy of respiration rate for patients at rest positions. The overall error in the respiration rate calculation is obtained 0.53% considering SPR-BTA spirometer as the reference. Five types of respiration disorders, Bradapnea, Tachypnea, Cheyn-stokes, Kaussmal, and Biot's breathing are classified based on hierarchical Support Vector Machine (SVM) with seven different features. We have evaluated the performance of the proposed classification while it is individualized to every subject (case 1) as well as considering all subjects (case 2). Since the selection of kernel function is a key factor to decide SVM's performance, in this paper three different kernel functions are evaluated. The experiments are conducted with 11 subjects and the average accuracy of 94.52% for case 1 and the accuracy of 81.29% for case 2 are achieved based on Radial Basis Function (RBF). Finally, a performance evaluation has been done for normal and impaired subjects considering sensitivity, specificity and G-mean parameters of different kernel

  2. Accurate crop classification using hierarchical genetic fuzzy rule-based systems

    Science.gov (United States)

    Topaloglou, Charalampos A.; Mylonas, Stelios K.; Stavrakoudis, Dimitris G.; Mastorocostas, Paris A.; Theocharis, John B.

    2014-10-01

    This paper investigates the effectiveness of an advanced classification system for accurate crop classification using very high resolution (VHR) satellite imagery. Specifically, a recently proposed genetic fuzzy rule-based classification system (GFRBCS) is employed, namely, the Hierarchical Rule-based Linguistic Classifier (HiRLiC). HiRLiC's model comprises a small set of simple IF-THEN fuzzy rules, easily interpretable by humans. One of its most important attributes is that its learning algorithm requires minimum user interaction, since the most important learning parameters affecting the classification accuracy are determined by the learning algorithm automatically. HiRLiC is applied in a challenging crop classification task, using a SPOT5 satellite image over an intensively cultivated area in a lake-wetland ecosystem in northern Greece. A rich set of higher-order spectral and textural features is derived from the initial bands of the (pan-sharpened) image, resulting in an input space comprising 119 features. The experimental analysis proves that HiRLiC compares favorably to other interpretable classifiers of the literature, both in terms of structural complexity and classification accuracy. Its testing accuracy was very close to that obtained by complex state-of-the-art classification systems, such as the support vector machines (SVM) and random forest (RF) classifiers. Nevertheless, visual inspection of the derived classification maps shows that HiRLiC is characterized by higher generalization properties, providing more homogeneous classifications that the competitors. Moreover, the runtime requirements for producing the thematic map was orders of magnitude lower than the respective for the competitors.

  3. Optimizing an estuarine water quality monitoring program through an entropy-based hierarchical spatiotemporal Bayesian framework

    Science.gov (United States)

    Alameddine, Ibrahim; Karmakar, Subhankar; Qian, Song S.; Paerl, Hans W.; Reckhow, Kenneth H.

    2013-10-01

    The total maximum daily load program aims to monitor more than 40,000 standard violations in around 20,000 impaired water bodies across the United States. Given resource limitations, future monitoring efforts have to be hedged against the uncertainties in the monitored system, while taking into account existing knowledge. In that respect, we have developed a hierarchical spatiotemporal Bayesian model that can be used to optimize an existing monitoring network by retaining stations that provide the maximum amount of information, while identifying locations that would benefit from the addition of new stations. The model assumes the water quality parameters are adequately described by a joint matrix normal distribution. The adopted approach allows for a reduction in redundancies, while emphasizing information richness rather than data richness. The developed approach incorporates the concept of entropy to account for the associated uncertainties. Three different entropy-based criteria are adopted: total system entropy, chlorophyll-a standard violation entropy, and dissolved oxygen standard violation entropy. A multiple attribute decision making framework is adopted to integrate the competing design criteria and to generate a single optimal design. The approach is implemented on the water quality monitoring system of the Neuse River Estuary in North Carolina, USA. The model results indicate that the high priority monitoring areas identified by the total system entropy and the dissolved oxygen violation entropy criteria are largely coincident. The monitoring design based on the chlorophyll-a standard violation entropy proved to be less informative, given the low probabilities of violating the water quality standard in the estuary.

  4. Fabrication of semi-transparent super-hydrophobic surface based on silica hierarchical structures

    KAUST Repository

    Chen, Ping-Hei

    2011-01-01

    This study successfully develops a versatile method of producing superhydrophobic surfaces with micro/nano-silica hierarchical structures on glass surfaces. Optically transparent super hydrophobic silica thin films were prepared by spin-coating silica particles suspended in a precursor solution of silane, ethanol, and H2O with molar ratio of 1:4:4. The resulting super hydrophobic films were characterized by scanning electron microscopy (SEM), optical transmission, and contact angle measurements. The glass substrates in this study were modified with different particles: micro-silica particles, nano-silica particles, and hierarchical structures. This study includes SEM micrographs of the modified glass surfaces with hierarchical structures at different magnifications. © 2011 The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.

  5. Hierarchical hybrid testability modeling and evaluation method based on information fusion

    Institute of Scientific and Technical Information of China (English)

    Xishan Zhang; Kaoli Huang; Pengcheng Yan; Guangyao Lian

    2015-01-01

    In order to meet the demand of testability analysis and evaluation for complex equipment under a smal sample test in the equipment life cycle, the hierarchical hybrid testability model-ing and evaluation method (HHTME), which combines the testabi-lity structure model (TSM) with the testability Bayesian networks model (TBNM), is presented. Firstly, the testability network topo-logy of complex equipment is built by using the hierarchical hybrid testability modeling method. Secondly, the prior conditional prob-ability distribution between network nodes is determined through expert experience. Then the Bayesian method is used to update the conditional probability distribution, according to history test information, virtual simulation information and similar product in-formation. Final y, the learned hierarchical hybrid testability model (HHTM) is used to estimate the testability of equipment. Compared with the results of other modeling methods, the relative deviation of the HHTM is only 0.52%, and the evaluation result is the most accurate.

  6. Process-based hierarchical models for coupling high-dimensional LiDAR and forest variables over large geographic domains

    OpenAIRE

    Andrew O. Finley; Banerjee, Sudipto; Zhou, Yuzhen; Cook, Bruce D

    2016-01-01

    Recent advancements in remote sensing technology, specifically Light Detection and Ranging (LiDAR) sensors, provide the data needed to quantify forest characteristics at a fine spatial resolution over large geographic domains. From an inferential standpoint, there is interest in prediction and interpolation of the often spatially misaligned LiDAR signals and forest variables. We propose a fully process-based Bayesian hierarchical model for above ground biomass (AGB) and LiDAR signals. The pro...

  7. Distributed Smart Decision-Making for a Multimicrogrid System Based on a Hierarchical Interactive Architecture

    DEFF Research Database (Denmark)

    Marzband, Mousa; Parhizi, Narges; Savaghebi, Mehdi;

    2016-01-01

    In this paper, a comprehensive real-time interactive EMS framework for the utility and multiple electrically-coupled MGs is proposed. A hierarchical bi-level control scheme-BLCS with primary and secondary level controllers is applied in this regard. The proposed hierarchical architecture consists...... are treated as uncertainties in the proposed structure. In order to handle the uncertainties, Taguchi0s orthogonal array testing-TOAT approach is utilized. Then, the shortage or surplus of the MGs power should be submitted to a central EMS-CEMS in the secondary-level. In order to validate the proposed...

  8. Page Layout Analysis of the Document Image Based on the Region Classification in a Decision Hierarchical Structure

    Directory of Open Access Journals (Sweden)

    Hossein Pourghassem

    2010-10-01

    Full Text Available The conversion of document image to its electronic version is a very important problem in the saving, searching and retrieval application in the official automation system. For this purpose, analysis of the document image is necessary. In this paper, a hierarchical classification structure based on a two-stage segmentation algorithm is proposed. In this structure, image is segmented using the proposed two-stage segmentation algorithm. Then, the type of the image regions such as document and non-document image is determined using multiple classifiers in the hierarchical classification structure. The proposed segmentation algorithm uses two algorithms based on wavelet transform and thresholding. Texture features such as correlation, homogeneity and entropy that extracted from co-occurrenc matrix and also two new features based on wavelet transform are used to classifiy and lable the regions of the image. The hierarchical classifier is consisted of two Multilayer Perceptron (MLP classifiers and a Support Vector Machine (SVM classifier. The proposed algorithm is evaluated on a database consisting of document and non-document images that provides from Internet. The experimental results show the efficiency of the proposed approach in the region segmentation and classification. The proposed algorithm provides accuracy rate of 97.5% on classification of the regions.

  9. Hierarchical Communication Diagrams

    OpenAIRE

    Marcin Szpyrka; Piotr Matyasik; Jerzy Biernacki; Agnieszka Biernacka; Michał Wypych; Leszek Kotulski

    2016-01-01

    Formal modelling languages range from strictly textual ones like process algebra scripts to visual modelling languages based on hierarchical graphs like coloured Petri nets. Approaches equipped with visual modelling capabilities make developing process easier and help users to cope with more complex systems. Alvis is a modelling language that combines possibilities of formal models verification with flexibility and simplicity of practical programming languages. The paper deals with hierarchic...

  10. Hierarchical Dirichlet Scaling Process

    OpenAIRE

    Kim, Dongwoo; Oh, Alice

    2014-01-01

    We present the \\textit{hierarchical Dirichlet scaling process} (HDSP), a Bayesian nonparametric mixed membership model. The HDSP generalizes the hierarchical Dirichlet process (HDP) to model the correlation structure between metadata in the corpus and mixture components. We construct the HDSP based on the normalized gamma representation of the Dirichlet process, and this construction allows incorporating a scaling function that controls the membership probabilities of the mixture components. ...

  11. LiDAR based prediction of forest biomass using hierarchical models with spatially varying coefficients

    Science.gov (United States)

    Babcock, Chad; Finley, Andrew O.; Bradford, John B.; Kolka, Randall K.; Birdsey, Richard A.; Ryan, Michael G.

    2015-01-01

    Many studies and production inventory systems have shown the utility of coupling covariates derived from Light Detection and Ranging (LiDAR) data with forest variables measured on georeferenced inventory plots through regression models. The objective of this study was to propose and assess the use of a Bayesian hierarchical modeling framework that accommodates both residual spatial dependence and non-stationarity of model covariates through the introduction of spatial random effects. We explored this objective using four forest inventory datasets that are part of the North American Carbon Program, each comprising point-referenced measures of above-ground forest biomass and discrete LiDAR. For each dataset, we considered at least five regression model specifications of varying complexity. Models were assessed based on goodness of fit criteria and predictive performance using a 10-fold cross-validation procedure. Results showed that the addition of spatial random effects to the regression model intercept improved fit and predictive performance in the presence of substantial residual spatial dependence. Additionally, in some cases, allowing either some or all regression slope parameters to vary spatially, via the addition of spatial random effects, further improved model fit and predictive performance. In other instances, models showed improved fit but decreased predictive performance—indicating over-fitting and underscoring the need for cross-validation to assess predictive ability. The proposed Bayesian modeling framework provided access to pixel-level posterior predictive distributions that were useful for uncertainty mapping, diagnosing spatial extrapolation issues, revealing missing model covariates, and discovering locally significant parameters.

  12. Hierarchical multiple binary image encryption based on a chaos and phase retrieval algorithm in the Fresnel domain

    Science.gov (United States)

    Wang, Zhipeng; Lv, Xiaodong; Wang, Hongjuan; Hou, Chenxia; Gong, Qiong; Qin, Yi

    2016-03-01

    Based on the chaos and phase retrieval algorithm, a hierarchical multiple binary image encryption is proposed. In the encryption process, each plaintext is encrypted into a diffraction intensity pattern by two chaos-generated random phase masks (RPMs). Thereafter, the captured diffraction intensity patterns are partially selected by different binary masks and then combined together to form a single intensity pattern. The combined intensity pattern is saved as ciphertext. For decryption, an iterative phase retrieval algorithm is performed, in which a support constraint in the output plane and a median filtering operation are utilized to achieve a rapid convergence rate without a stagnation problem. The proposed scheme has a simple optical setup and large encryption capacity. In particular, it is well suited for constructing a hierarchical security system. The security and robustness of the proposal are also investigated.

  13. HIERARCHICAL ACCESS CONTROL IN DYNAMIC PEER GROUPS USING SYMMETRIC POLYNOMIAL AND TREE BASED GROUP ELLIPTIC CURVE DIFFIE HELLMAN SCHEME

    Directory of Open Access Journals (Sweden)

    Nafeesa Begum Jeddy

    2014-01-01

    Full Text Available Hierarchical Access Control in group communication is an active area of research which is difficult to achieve it. Its primary objective is to allow users of a higher authority group to access information or resource held by lower group users and preventing the lower group users to access information held by higher class users. Large collection of collaborative applications in organizations inherently has hierarchical structures for functioning, where providing security by efficient group key management is a big challenging issue. While preserving centralized methods for hierarchical access control, it is difficult to achieve efficiency as a single membership change will result in lot of changes which are difficult to maintain. So, using distributed key agreement techniques is more appropriate for this scenario. This study explore on novel group key agreement approach, which combines both the symmetric polynomial scheme and Tree Based Group elliptic Curve key exchange. Also, it yields a secure protocol suite that is good in fault-tolerant and simple. The efficiency of SP-TGECDH is better than many other schemes. Using TGECDH makes the scheme suitable small Low powered devices.

  14. Hierarchical distance-based fuzzy approach to evaluate urban water supply systems in a semi-arid region

    OpenAIRE

    Yekta, Tahereh Sadeghi; Khazaei, Mohammad; Nabizadeh, Ramin; MAHVI, Amir Hossein; Nasseri, Simin; Yari, Ahmad Reza

    2015-01-01

    Hierarchical distance-based fuzzy multi-criteria group decision making was served as a tool to evaluate the drinking water supply systems of Qom, a semi-arid city located in central part of Iran. A list of aspects consisting of 6 criteria and 35 sub-criteria were evaluated based on a linguistic term set by five decision-makers. Four water supply alternatives including “Public desalinated distribution system”, “PET Bottled Drinking Water”, “Private desalinated water suppliers” and “Household d...

  15. 3D hierarchical architectures based on self-rolled-up silicon nitride membranes

    International Nuclear Information System (INIS)

    This study presents the superior structural versatility of strained silicon nitride (SiNx) membranes as a platform for three-dimensional (3D) hierarchical tubular architectures. The effects of compressive and tensile stressed SiNx layer thickness on the self-rolled-up tube curvature, the sacrificial layer etching anisotropy on rolling direction and chirality, and stress engineering by localized thickness control or thermal treatment, are explored systematically. Using strained SiNx membranes as an electrically insulating and optically transparent mechanical support, compact 3D hierarchical architectures involving carbon nanotube arrays and passive electronic components are demonstrated by releasing the functional structures deposited and patterned in 2D. These examples highlight the uniqueness of this platform that exploits 2D processing and self-assembly to achieve highly functional 3D structures. (paper)

  16. Hierarchical Satellite-based Approach to Global Monitoring of Crop Condition and Food Production

    Science.gov (United States)

    Zheng, Y.; Wu, B.; Gommes, R.; Zhang, M.; Zhang, N.; Zeng, H.; Zou, W.; Yan, N.

    2014-12-01

    The assessment of global food security goes beyond the mere estimate of crop production: It needs to take into account the spatial and temporal patterns of food availability, as well as physical and economic access. Accurate and timely information is essential to both food producers and consumers. Taking advantage of multiple new remote sensing data sources, especially from Chinese satellites, such as FY-2/3A, HJ-1 CCD, CropWatch has expanded the scope of its international analyses through the development of new indicators and an upgraded operational methodology. The new monitoring approach adopts a hierarchical system covering four spatial levels of detail: global (sixty-five Monitoring and Reporting Units, MRU), seven major production zones (MPZ), thirty-one key countries (including China) and "sub- countries." The thirty-one countries encompass more that 80% of both global exports and production of four major crops (maize, rice, soybean and wheat). The methodology resorts to climatic and remote sensing indicators at different scales, using the integrated information to assess global, regional, and national (as well as sub-national) crop environmental condition, crop condition, drought, production, and agricultural trends. The climatic indicators for rainfall, temperature, photosynthetically active radiation (PAR) as well as potential biomass are first analysed at global scale to describe overall crop growing conditions. At MPZ scale, the key indicators pay more attention to crops and include Vegetation health index (VHI), Vegetation condition index (VCI), Cropped arable land fraction (CALF) as well as Cropping intensity (CI). Together, they characterise agricultural patterns, farming intensity and stress. CropWatch carries out detailed crop condition analyses for thirty one individual countries at the national scale with a comprehensive array of variables and indicators. The Normalized difference vegetation index (NDVI), cropped areas and crop condition are

  17. Predicting Mathematics 1 Course Success by Using Hierarchical Adaptive Network Based Fuzzy Inference System

    Directory of Open Access Journals (Sweden)

    Özcan Dülger

    2014-05-01

    Full Text Available Predicting Mathematics 1 course success of students is very important to prepare them before the semester. It is difficult to obtain solution because of the non-linear property of data set. Fuzzy logic is one of the common methods for the problems which involve numeric values. In fuzzy logic, it is important to determine membership functions and their parameter's values correctly. This can be done by an expert or can be learned with a data set. In this study, we aimed to predict the Mathematics 1 course success of 434 students who enrolled to Engineering Faculty of Pamukkale University in 2007-2008 academic year by using their university exam data. For this, the adaptive-network-based fuzzy inference system (ANFIS which combines the important characteristics of artificial neural network and fuzzy logic was used. In training section, nine parameters which are selected from sixteen parameters in data set with different combinations were given to the ANFIS. When an ANFIS structure with nine input parameters has at least three membership functions for each input, it will have at least 3^9 fuzzy rules. Because of this, the training part is too slow and too much memory is needed. Instead of this inefficient structure, a hierarchical method was proposed. In this method, the ANFIS is partitioned to the sub-systems. Each sub-system performs some part of input parameters and sends their result to the final ANFIS structure to obtain the overall system output. After testing with one-third of data set, two best prediction results with ratio 77.77% and 78.47% are obtained. When these results are analyzed, it is seen that 64 successful students from 85 students and 48 unsuccessful students from 59 students in Mathematics 1 course were predicted truly in the result with ratio 77.77%. Similarly, 69 successful students from 85 students, and 44 unsuccessful students from 59 students were predicted truly in the result with ratio 78.47%.

  18. Climate information based streamflow and rainfall forecasts for Huai River basin using hierarchical Bayesian modeling

    OpenAIRE

    Chen, X.; Hao, Z; N. Devineni; U. Lall

    2014-01-01

    A Hierarchal Bayesian model is presented for one season-ahead forecasts of summer rainfall and streamflow using exogenous climate variables for east central China. The model provides estimates of the posterior forecasted probability distribution for 12 rainfall and 2 streamflow stations considering parameter uncertainty, and cross-site correlation. The model has a multi-level structure with regression coefficients modeled from a common multi-variate normal distribution resul...

  19. Climate information based streamflow and rainfall forecasts for Huai River Basin using Hierarchical Bayesian Modeling

    OpenAIRE

    Chen, X.; Hao, Z; N. Devineni; U. Lall

    2013-01-01

    A Hierarchal Bayesian model for forecasting regional summer rainfall and streamflow season-ahead using exogenous climate variables for East Central China is presented. The model provides estimates of the posterior forecasted probability distribution for 12 rainfall and 2 streamflow stations considering parameter uncertainty, and cross-site correlation. The model has a multilevel structure with regression coefficients modeled from a common multivariate normal distribution results in partial-po...

  20. Face Recognition Algorithm Based on Doubly Truncated Gaussian Mixture Model Using Hierarchical Clustering Algorithm

    OpenAIRE

    D. Haritha; K. Srinivasa Rao; Ch.Satyanarayana

    2012-01-01

    A robust and efficient face recognition system was developed and evaluated. The each individual face is characterized by 2D-DCT coefficients which follows a finite mixture of doubly truncated Gaussian distribution. In modelling the features vector of the face the number of components (in the mixture model) are determined by hierarchical clustering. The model parameters are estimated using EM algorithm. The face recognition algorithm is developed by maximum likelihood under Baysian frame. The ...

  1. Hierarchical Formation of Fibrillar and Lamellar Self-Assemblies from Guanosine-Based Motifs

    Directory of Open Access Journals (Sweden)

    Paolo Neviani

    2010-01-01

    Full Text Available Here we investigate the supramolecular polymerizations of two lipophilic guanosine derivatives in chloroform by light scattering technique and TEM experiments. The obtained data reveal the presence of several levels of organization due to the hierarchical self-assembly of the guanosine units in ribbons that in turn aggregate in fibrillar or lamellar soft structures. The elucidation of these structures furnishes an explanation to the physical behaviour of guanosine units which display organogelator properties.

  2. Hierarchical systems

    NARCIS (Netherlands)

    Hamers, A.S.

    2016-01-01

    The thesis addresses the long-term dynamical evolution of hierarchical multiple systems. First, we consider the evolution of orbits of stars orbiting a supermassive black hole (SBH). We study the long-term evolution and compute tidal disruption rates of stars by the SBH. Such disruption events revea

  3. SMR-Based Adaptive Mobility Management Scheme in Hierarchical SIP Networks

    OpenAIRE

    KwangHee Choi; Joon-Min Gil

    2014-01-01

    In hierarchical SIP networks, paging is performed to reduce location update signaling cost for mobility management. However, the cost efficiency largely depends on each mobile node’s session-to-mobility-ratio (SMR), which is defined as a ratio of the session arrival rate to the movement rate. In this paper, we propose the adaptive mobility management scheme that can determine the policy regarding to each mobile node’s SMR. Each mobile node determines whether the paging is applied or not after...

  4. Cluster based hierarchical resource searching model in P2P network

    Institute of Scientific and Technical Information of China (English)

    Yang Ruijuan; Liu Jian; Tian Jingwen

    2007-01-01

    For the problem of large network load generated by the Gnutella resource-searching model in Peer to Peer (P2P) network, a improved model to decrease the network expense is proposed, which establishes a duster in P2P network,auto-organizes logical layers, and applies a hybrid mechanism of directional searching and flooding. The performance analysis and simulation results show that the proposed hierarchical searching model has availably reduced the generated message load and that its searching-response time performance is as fairly good as that of the Gnutella model.

  5. Structure Determination and Estimation of Hierarchical Archimedean Copulas Based on Kendall Correlation Matrix

    Czech Academy of Sciences Publication Activity Database

    Górecki, J.; Holeňa, Martin

    Cham: Springer, 2014 - (Appice, A.; Ceci, M.; Loglisci, C.; Manco, G.; Masciari, E.; Ras, Z.), s. 132-147. (Lecture Notes in Artificial Intelligence . 8399). ISBN 978-3-319-08406-0. ISSN 0302-9743. [NFMCP 2013. International Workshop /2./. Prague (CZ), 27.09.2013] R&D Projects: GA ČR GA13-17187S Institutional support: RVO:67985807 Keywords : Copula * Hierarchical Archimedean copula * Copula estimation * Structure determination * Kendall’s correlation coefficient Subject RIV: IN - Informatics, Computer Science

  6. A Marker-Based Approach for the Automated Selection of a Single Segmentation from a Hierarchical Set of Image Segmentations

    Science.gov (United States)

    Tarabalka, Y.; Tilton, J. C.; Benediktsson, J. A.; Chanussot, J.

    2012-01-01

    The Hierarchical SEGmentation (HSEG) algorithm, which combines region object finding with region object clustering, has given good performances for multi- and hyperspectral image analysis. This technique produces at its output a hierarchical set of image segmentations. The automated selection of a single segmentation level is often necessary. We propose and investigate the use of automatically selected markers for this purpose. In this paper, a novel Marker-based HSEG (M-HSEG) method for spectral-spatial classification of hyperspectral images is proposed. Two classification-based approaches for automatic marker selection are adapted and compared for this purpose. Then, a novel constrained marker-based HSEG algorithm is applied, resulting in a spectral-spatial classification map. Three different implementations of the M-HSEG method are proposed and their performances in terms of classification accuracies are compared. The experimental results, presented for three hyperspectral airborne images, demonstrate that the proposed approach yields accurate segmentation and classification maps, and thus is attractive for remote sensing image analysis.

  7. Cellular Decomposition Based Hybrid-Hierarchical Control Systems with Applications to Flight Management Systems

    Science.gov (United States)

    Caines, P. E.

    1999-01-01

    The work in this research project has been focused on the construction of a hierarchical hybrid control theory which is applicable to flight management systems. The motivation and underlying philosophical position for this work has been that the scale, inherent complexity and the large number of agents (aircraft) involved in an air traffic system imply that a hierarchical modelling and control methodology is required for its management and real time control. In the current work the complex discrete or continuous state space of a system with a small number of agents is aggregated in such a way that discrete (finite state machine or supervisory automaton) controlled dynamics are abstracted from the system's behaviour. High level control may then be either directly applied at this abstracted level, or, if this is in itself of significant complexity, further layers of abstractions may be created to produce a system with an acceptable degree of complexity at each level. By the nature of this construction, high level commands are necessarily realizable at lower levels in the system.

  8. An Integrated Metric Based Hierarchical Routing Algorithm in Broadband Communication System

    Institute of Scientific and Technical Information of China (English)

    SHI Chengge; HU Jiajun; Milton Chang

    2001-01-01

    We give an integrated metric basedhierarchical routing algorithm - FMRSF (FunctionFi(.) minimum routing selected first) algorithm inbroadband communication system in this paper. Withthe authors' analysis strategy, this paper gives a rout-ing solution for hierarchical communication system,and the solution is suited to both ATM network andIP network. Due to the highMevel logic network map-ping in a hierarchical communication system, a largecommunication network can be described as a moresimple logic network on a high level. But, it is dif-ficult to evaluate the QoS parameters of the relativefactors of a logic network (For example: the time de-lay and the bandwidth of logic nodes or logic links).We develop our strategy with FMRSF - algorithm fordifferent routing path, and select the reasonable pathfor one communication session. After designing an in-tegrated metric function describing the QoS metrics ofthe relative factors of a logic network on the high lev-els in a broadband communication system, we provethat the new routing algorithm - FMRSF algorithm ismore simple and applicable, compared with the globaloptimum algorithm.

  9. SMR-Based Adaptive Mobility Management Scheme in Hierarchical SIP Networks

    Directory of Open Access Journals (Sweden)

    KwangHee Choi

    2014-10-01

    Full Text Available In hierarchical SIP networks, paging is performed to reduce location update signaling cost for mobility management. However, the cost efficiency largely depends on each mobile node’s session-to-mobility-ratio (SMR, which is defined as a ratio of the session arrival rate to the movement rate. In this paper, we propose the adaptive mobility management scheme that can determine the policy regarding to each mobile node’s SMR. Each mobile node determines whether the paging is applied or not after comparing its SMR with the threshold. In other words, the paging is applied to a mobile node when a mobile node’s SMR is less than the threshold. Therefore, the proposed scheme provides a way to minimize signaling costs according to each mobile node’s SMR. We find out the optimal threshold through performance analysis, and show that the proposed scheme can reduce signaling cost than the existing SIP and paging schemes in hierarchical SIP networks.

  10. Image Segmentation Method Based On Finite Doubly Truncated Bivariate Gaussian Mixture Model with Hierarchical Clustering

    Directory of Open Access Journals (Sweden)

    G V S Rajkumar

    2011-07-01

    Full Text Available Image segmentation is one of the most important area of image retrieval. In colour image segmentation the feature vector of each image region is 'n' dimension different from grey level image. In this paper a new image segmentation algorithm is developed and analyzed using the finite mixture of doubly truncated bivariate Gaussian distribution by integrating with the hierarchical clustering. The number of image regions in the whole image is determined using the hierarchical clustering algorithm. Assuming that a bivariate feature vector (consisting of Hue angle and Saturation of each pixel in the image region follows a doubly truncated bivariate Gaussian distribution, the segmentation algorithm is developed. The model parameters are estimated using EM-Algorithm, the updated equations of EM-Algorithm for a finite mixture of doubly truncated Gaussian distribution are derived. A segmentation algorithm for colour images is proposed by using component maximum likelihood. The performance of the developed algorithm is evaluated by carrying out experimentation with five images taken form Berkeley image dataset and computing the image segmentation metrics like, Global Consistency Error (GCE, Variation of Information (VOI, and Probability Rand Index (PRI. The experimentation results show that this algorithm outperforms the existing image segmentation algorithms.

  11. A debugging system for azimuthally acoustic logging tools based on modular and hierarchical design ideas

    Science.gov (United States)

    Zhang, K.; Ju, X. D.; Lu, J. Q.; Men, B. Y.

    2016-08-01

    On the basis of modular and hierarchical design ideas, this study presents a debugging system for an azimuthally sensitive acoustic bond tool (AABT). The debugging system includes three parts: a personal computer (PC), embedded front-end machine and function expansion boards. Modular and hierarchical design ideas are conducted in all design and debug processes. The PC communicates with the front-end machine via the Internet, and the front-end machine and function expansion boards connect each other by the extended parallel bus. In this method, the three parts of the debugging system form stable and high-speed data communication. This study not only introduces the system-level debugging and sub-system level debugging of the tool but also the debugging of the analogue signal processing board, which is important and greatly used in logging tools. Experiments illustrate that the debugging system can greatly improve AABT verification and calibration efficiency and that, board-level debugging can examine and improve analogue signal processing boards. The design thinking is clear and the design structure is reasonable, thus making it easy to extend and upgrade the debugging system.

  12. Direct electrochemistry of horseradish peroxidase based on hierarchical porous calcium phosphate microspheres

    International Nuclear Information System (INIS)

    Biomorphic calcium phosphate (CaP) microspheres with hierarchical porous structure were synthesized using natural cole pollen grains as templates and were further employed for the immobilization of horseradish peroxidase (HRP). Scanning electron microscopy and Fourier transform infrared spectroscopy revealed (a) the porous structure of the CaP microspheres, (b) the effective immobilization, and (c) the retention of the conformation of HRP on CaP. The immobilized HRP was placed on a glassy carbon electrode where it underwent a direct, fully reversible, and surface-controlled redox reaction with an electron transfer rate constant of 1.96 s−1. It also exhibits high sensitivity to the reduction of H2O2. The response to H2O2 is linear in the 5.00 nM to 1.27 μM concentration range, and the sensitivity is 30357 μA⋅mM−1⋅cm−2. The detection limit (at an SNR of 3) is as low as 1.30 nM. The apparent Michaelis–Menten constant (KMapp) of the immobilized enzyme is 0.92 μM. This new CaP with hierarchical porous structure therefore represents a material that can significantly promote the direct electron transfer between HRP and an electrode, and is quite attractive with respect to the construction of biosensors. (author)

  13. Improved Reception Schemes for Digital Video Broadcasting Based on Hierarchical Modulation

    Directory of Open Access Journals (Sweden)

    S. M. S. Sadough

    2011-04-01

    Full Text Available In this paper, we first provide an overview of Hierarchical Modulation (HM along with the opportunities offered by this modulation in the context of the recent Digital Video Broadcasting standard for Satellite to Handheld devices (DVB-SH.With HM, the binary data is partitioned into a “high-priority” (HP and a “low-priority” (LP bit stream that are separately and independently encoded before being mapped on non-uniformly spaced constellation points. We will show that the robustness of the HP stream is obtained at the expense of performance degradation of the less protected LP stream with respect to a non-hierarchical modulation. To overcome this inherent drawback of HM, we propose two different reception schemes for improving the bit error rate performance of the less protected LP stream, while keeping the HP decoding performance unchanged. The important point is that in one of the proposed reception schemes, the performance improvement is achieved together with the reduction of the receiver’s complexity.

  14. Shadow-Based Hierarchical Matching for the Automatic Registration of Airborne LiDAR Data and Space Imagery

    Directory of Open Access Journals (Sweden)

    Alireza Safdarinezhad

    2016-06-01

    Full Text Available The automatic registration of LiDAR data and optical images, which are heterogeneous data sources, has been a major research challenge in recent years. In this paper, a novel hierarchical method is proposed in which the least amount of interaction of a skilled operator is required. Thereby, two shadow extraction schemes, one from LiDAR and the other from high-resolution satellite images, were used, and the obtained 2D shadow maps were then considered as prospective matching entities. Taken as the base, the reconstructed LiDAR shadows were transformed to image shadows using a four-step hierarchical method starting from a coarse 2D registration model and leading to a fine 3D registration model. In the first step, a general matching was performed in the frequency domain that yielded a rough 2D similarity model that related the LiDAR and image shadow masks. This model was further improved by modeling and compensating for the local geometric distortions that existed between the two heterogeneous data sources. In the third step, shadow masks, which were organized as segmented matched patches, were the subjects of a coinciding procedure that resulted in a coarse 3D registration model. In the last hierarchical step, that model was ultimately reinforced via a precise matching between the LiDAR and image edges. The evaluation results, which were conducted on six datasets and from different relative and absolute aspects, demonstrated the efficiency of the proposed method, which had a very promising accuracy on the order of one pixel.

  15. Visible-light driven biofuel cell based on hierarchically branched titanium dioxide nanorods photoanode for tumor marker detection.

    Science.gov (United States)

    Gao, Chaomin; Zhang, Lina; Wang, Yanhu; Yu, Jinghua; Song, Xianrang

    2016-09-15

    In this work, a novel sensing platform based on visible light driven biofuel cell (BFC) has been facilely designed for sensitive detection of prostate-specific antigen (PSA) with the photo-response bioanode, realizing the dual route energy conversion of light energy and chemical energy to electricity. The hierarchical branched TiO2 nanorods (B-TiO2 NRs) decorated with CdS quantum dots (QDs) act as the substrate to confine glucose dehydrogenase (GDH) for the visible light driven glucose oxidation at the bioanode. Three dimensional flowers like hierarchical carbon/gold nanoparticles/bilirubin oxidase (3D FCM/AuNPs/BOD) bioconjugate served as biocatalyst for O2 reduction at the biocathode. With an increase in the concentration of PSA, the amount of BOD labels on biocathode increases, thus leading to the higher current output of the as-proposed visible light driven BFC. Based on this, this sensing platform provide great performance in sensitivity and specificity, increasing linear detection range from 0.3pgmL(-1) to 7μgmL(-1) with a detection limit of 0.1pgmL(-1). Most importantly, our new sensing strategy provided a simple and inexpensive sensing platform for tumor markers detection, suggesting its wide potential applications for clinical diagnostics. PMID:27135937

  16. A supplier selection using a hybrid grey based hierarchical clustering and artificial bee colony

    Directory of Open Access Journals (Sweden)

    Farshad Faezy Razi

    2014-06-01

    Full Text Available Selection of one or a combination of the most suitable potential providers and outsourcing problem is the most important strategies in logistics and supply chain management. In this paper, selection of an optimal combination of suppliers in inventory and supply chain management are studied and analyzed via multiple attribute decision making approach, data mining and evolutionary optimization algorithms. For supplier selection in supply chain, hierarchical clustering according to the studied indexes first clusters suppliers. Then, according to its cluster, each supplier is evaluated through Grey Relational Analysis. Then the combination of suppliers’ Pareto optimal rank and costs are obtained using Artificial Bee Colony meta-heuristic algorithm. A case study is conducted for a better description of a new algorithm to select a multiple source of suppliers.

  17. Climate information based streamflow and rainfall forecasts for Huai River Basin using Hierarchical Bayesian Modeling

    Directory of Open Access Journals (Sweden)

    X. Chen

    2013-09-01

    Full Text Available A Hierarchal Bayesian model for forecasting regional summer rainfall and streamflow season-ahead using exogenous climate variables for East Central China is presented. The model provides estimates of the posterior forecasted probability distribution for 12 rainfall and 2 streamflow stations considering parameter uncertainty, and cross-site correlation. The model has a multilevel structure with regression coefficients modeled from a common multivariate normal distribution results in partial-pooling of information across multiple stations and better representation of parameter and posterior distribution uncertainty. Covariance structure of the residuals across stations is explicitly modeled. Model performance is tested under leave-10-out cross-validation. Frequentist and Bayesian performance metrics used include Receiver Operating Characteristic, Reduction of Error, Coefficient of Efficiency, Rank Probability Skill Scores, and coverage by posterior credible intervals. The ability of the model to reliably forecast regional summer rainfall and streamflow season-ahead offers potential for developing adaptive water risk management strategies.

  18. Mechanism of antifreeze proteins action, based on Hierarchic theory of water and new ''clusterphilic'' interaction

    CERN Document Server

    Kaivarainen, A

    2001-01-01

    A basically new Hierarchic theory, general for solids and liquids (Kaivarainen, 2001, 2000, 1995, 1992), has been briefly described and illustrated by computer simulations on examples of water and ice. Full description of theory and its numerous applications are presented in series of articles at the arXiv of Los-Alamos (see http://arXiv.org/abs/physics/0102086). New clusterphilic interactions, intermediate between hydrophilic and hydrphobic, are introduced. They can be subdivided into: intramolecular - when water cluster is localized in the ''open'' states of big interdomain or intersubunit cavities and intermolecular clusterphilic interactions. Intermolecular clusterphilic interactions can be induced by very different macromolecules. The latter displays themselves in bordering of water cluster by macromolecules and forming so-called ''clustrons''. Clusterphilic interactions can play an important role in self-organization of biosystems, especially multiglobular allosteric enzymes, microtubules and the actin ...

  19. Self-Healing Underwater Superoleophobic and Antibiofouling Coatings Based on the Assembly of Hierarchical Microgel Spheres.

    Science.gov (United States)

    Chen, Kunlin; Zhou, Shuxue; Wu, Limin

    2016-01-26

    Marine biofouling has been plaguing people for thousands of years. While various strategies have been developed for antifouling (including superoleophobic) coatings, none of these exhibits self-healing properties because the bestowal of a zoetic self-repairing function to lifeless artificial water/solid interfacial materials is usually confronted with tremendous challenges. Here, we present a self-repairing underwater superoleophobic and antibiofouling coating through the self-assembly of hydrophilic polymeric chain modified hierarchical microgel spheres. The obtained surface material not only has excellent underwater superoleophobicity but also has very good subaqueous antibiofouling properties. More importantly, this surface material can recover the oil- and biofouling-resistant properties once its surface is mechanically damaged, similar to the skins of some marine organisms such as sharks or whales. This approach is feasible and easily mass-produced and could open a pathway and possibility for the fabrication of other self-healing functional water/solid interfacial materials. PMID:26687925

  20. Discrete and Continuous Optimization Based on Hierarchical Artificial Bee Colony Optimizer

    Directory of Open Access Journals (Sweden)

    Lianbo Ma

    2014-01-01

    Full Text Available This paper presents a novel optimization algorithm, namely, hierarchical artificial bee colony optimization (HABC, to tackle complex high-dimensional problems. In the proposed multilevel model, the higher-level species can be aggregated by the subpopulations from lower level. In the bottom level, each subpopulation employing the canonical ABC method searches the part-dimensional optimum in parallel, which can be constructed into a complete solution for the upper level. At the same time, the comprehensive learning method with crossover and mutation operator is applied to enhance the global search ability between species. Experiments are conducted on a set of 20 continuous and discrete benchmark problems. The experimental results demonstrate remarkable performance of the HABC algorithm when compared with other six evolutionary algorithms.

  1. A hierarchical scheduling and management solution for dynamic reconfiguration in FPGA-based embedded systems

    Science.gov (United States)

    Cervero, T.; Gómez, A.; López, S.; Sarmiento, R.; Dondo, J.; Rincón, F.; López, J. C.

    2013-05-01

    One of the limiting factors that have prevented a widely dissemination of the reconfigurable technology is the absence of an appropriate model for certain target applications capable of offering a reliable control. Moreover, the lack of flexible and easy-to-use scheduling and management systems are also relevant drawbacks to be considered. Under static scenarios, it is relatively easy to schedule and manage the reconfiguration process since all the variations corresponding to predetermined and well-known tasks. However, the difficulty increases when the adaptation needs of the overall system change semi-randomly according to the environmental fluctuations. In this context, this work proposes a change in the paradigm of dynamically reconfigurable systems, by attending to the dynamically reconfigurable control problematic as a whole, in which the scheduling and the placement issues are packed together as a hierarchical management structure, interacting together as one entity from the system point of view, but performing their tasks with certain degree of independence each other. In this sense, the top hierarchical level corresponds with a dynamic scheduler in charge of planning and adjusting all the reconfigurable modules according to the variations of the external stimulus. The lower level interacts with the physical layer of the device by means of instantiating, relocating, removing a reconfigurable module following the scheduler's instructions. In regards to how fast is the proposed solution, the total partial reconfiguration time achieved with this proposal has been measured and compared with other two approaches: 1) using traditional Xilinx's tools; 2) using an optimized version of the Xilinx's drivers. The collected numbers demonstrate that our solution reaches a gain up to 10 times faster than the other approaches.

  2. Magnetically recyclable Bi/Fe-based hierarchical nanostructures via self-assembly for environmental decontamination

    Science.gov (United States)

    Hu, Zhong-Ting; Chen, Zhong; Goei, Ronn; Wu, Weiyi; Lim, Teik-Thye

    2016-06-01

    Pristine bismuth ferrite usually possesses weak magnetic properties (e.g., saturation magnetization Ms pharmaceuticals and pesticides. Even at a low catalyst loading of 0.12 g L-1, the removal rate of organic pollutants (e.g., 5-fluorouracil, isoproturon) can be ~99% in 100 min under visible light irradiation. Besides, BFO-M is also a good adsorbent for different kinds of heavy metal ions (Pb(ii), Cr(iii), Cu(ii), As(v), etc.). For example, its maximal adsorption capacity for Pb(ii) is 214.5 mg g-1. The used BFO-M can be recovered via magnetic separation. The outstanding performances of BFO-M can be ascribed to its coral-like hierarchical morphology which consists of the self-assembly of 1D nanowires (~6 nm in diameter) and 2D ultrathin nanoflakes (~4.5 nm in thickness). A schematic illustration of its morphology formation is proposed.Pristine bismuth ferrite usually possesses weak magnetic properties (e.g., saturation magnetization Ms pharmaceuticals and pesticides. Even at a low catalyst loading of 0.12 g L-1, the removal rate of organic pollutants (e.g., 5-fluorouracil, isoproturon) can be ~99% in 100 min under visible light irradiation. Besides, BFO-M is also a good adsorbent for different kinds of heavy metal ions (Pb(ii), Cr(iii), Cu(ii), As(v), etc.). For example, its maximal adsorption capacity for Pb(ii) is 214.5 mg g-1. The used BFO-M can be recovered via magnetic separation. The outstanding performances of BFO-M can be ascribed to its coral-like hierarchical morphology which consists of the self-assembly of 1D nanowires (~6 nm in diameter) and 2D ultrathin nanoflakes (~4.5 nm in thickness). A schematic illustration of its morphology formation is proposed. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr03677e

  3. High performance solid state flexible supercapacitor based on molybdenum sulfide hierarchical nanospheres

    Science.gov (United States)

    Javed, Muhammad Sufyan; Dai, Shuge; Wang, Mingjun; Guo, Donglin; Chen, Lin; Wang, Xue; Hu, Chenguo; Xi, Yi

    2015-07-01

    Molybdenum sulfide (MoS2) hierarchical nanospheres are synthesized using a hydrothermal method and characterized by X-ray powder diffraction, Brunauer-Emmett-Teller, scanning electron microscopy and transmission electron microscopy. The prepared MoS2 is used to fabricate solid state flexible supercapacitors which show excellent electrochemical performance such as high capacitance 368 F g-1 at a scan rate of 5 mV s-1 and high power density of 128 W kg-1 at energy density of 5.42 Wh kg-1. The fabricated supercapacitor presents good characteristics such as lightweight, low cast, portability, high flexibility, and long term cycling stability by retaining 96.5% after 5000 cycles at constant discharge current of 0.8 mA. Electrochemical impedance spectroscopy (EIS) results reveal low resistance and suggest that MoS2 nanospheres would be a promising candidate for supercapacitors. Three charged supercapacitors connected in series can light 8 red color commercial light emitting diodes (LEDs) for 2 min, demonstrating its capability as a good storage device.

  4. AN OPTIMUM VEHICULAR PATH ALGORITHM FOR TRAFFIC NETWORK BASED ON HIERARCHICAL SPATIAL REASONING

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Human beings' intellection is the characteristic of a distinct hierarchy and can be taken to construct a heuristic in the shortest path algorithms.It is detailed in this paper how to utilize the hierarchical reasoning on the basis of greedy and directional strategy to establish a spatial heuristic,so as to improve running efficiency and suitability of shortest path algorithm for traffic network.The authors divide urban traffic network into three hierarchies and set forward a new node hierarchy division rule to avoid the unreliable solution of shortest path.It is argued that the shortest path,no matter distance shortest or time shortest,is usually not the favorite of drivers in practice.Some factors difficult to expect or quantify influence the drivers' choice greatly.It makes the drivers prefer choosing a less shortest,but more reliable or flexible path to travel on.The presented optimum path algorithm,in addition to the improvement of the running efficiency of shortest path algorithms up to several times,reduces the emergence of those factors,conforms to the intellection characteristic of human beings,and is more easily accepted by drivers.Moreover,it does not require the completeness of networks in the lowest hierarchy and the applicability and fault tolerance of the algorithm have improved.The experiment result shows the advantages of the presented algorithm.The authors argued that the algorithm has great potential application for navigation systems of large-scale traffic networks.

  5. Non-Markovian reduced dynamics based upon a hierarchical effective-mode representation

    Energy Technology Data Exchange (ETDEWEB)

    Burghardt, Irene [Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt (Germany); Martinazzo, Rocco [Dipartimento di Chimica, Universita degli Studi di Milano, v. Golgi 19, 20133 Milano (Italy); Hughes, Keith H. [School of Chemistry, Bangor University, Bangor, Gwynedd LL57 2UW (United Kingdom)

    2012-10-14

    A reduced dynamics representation is introduced which is tailored to a hierarchical, Mori-chain type representation of a bath of harmonic oscillators which are linearly coupled to a subsystem. We consider a spin-boson system where a single effective mode is constructed so as to absorb all system-environment interactions, while the residual bath modes are coupled bilinearly to the primary mode and among each other. Using a cumulant expansion of the memory kernel, correlation functions for the primary mode are obtained, which can be suitably approximated by truncated chains representing the primary-residual mode interactions. A series of reduced-dimensional bath correlation functions is thus obtained, which can be expressed as Fourier-Laplace transforms of spectral densities that are given in truncated continued-fraction form. For a master equation which is second order in the system-bath coupling, the memory kernel is re-expressed in terms of local-in-time equations involving auxiliary densities and auxiliary operators.

  6. Agent-Based Hierarchical Approach For Executing Bag-Of-Tasks In Clouds

    Directory of Open Access Journals (Sweden)

    Włodzimierz Funika

    2014-01-01

    Full Text Available Numerous unrelated, independent (no inter-task communication tasks called “bag-oftasks”(BoTs compared with message passing applications can be highly parallelised andexecuted in any acceptable order. A common practice when executing bag-of-tasks applications(BoT is to exploit the master-slave topology. Cloud environments offer some featuresthat facilitate executing BoT applications. One of the approaches to control cloud resourcesis to use agents that can flexibly act in a dynamic environment. Given these assumptions wedesigned a combination of these approaches, which can be classified as: a distributed, hierarchicalsolution to the issue of scalable executing of bag-of-tasks. The concept of our systemrelates to a project that is focused on processing huge quantities of data incoming from anetwork of sensors by the Internet. Our aim is to create a mechanism for processing such dataas a system which executes jobs while exploiting load balancing for cloud resources using,e.g., Eucalyptus. The idea is to create a hybrid architecture which takes advantage of somecentralized parts of the system and full distributedness in other parts. On the other handwe balance dependencies between the system components using a hierarchic master-slavestructure.

  7. Multiple Computing Task Scheduling Method Based on Dynamic Data Replication and Hierarchical Strategy

    Directory of Open Access Journals (Sweden)

    Xiang Zhou

    2014-02-01

    Full Text Available As for the problem of how to carry out task scheduling and data replication effectively in the grid and to reduce task’s execution time, this thesis proposes the task scheduling algorithm and the optimum dynamic data replication algorithm and builds a scheme to effectively combine these two algorithms. First of all, the scheme adopts the ISS algorithm considering the number of tasks waiting queue, the location of task demand data and calculation capacity of site by adopting the method of network structure’s hierarchical scheduling to calculate the cost of comprehensive task with the proper weight efficiency and search out the best compute node area. And then the algorithm of ODHRA is adopted to analyze the data transmission time, memory access latency, waiting copy requests in the queue and the distance between nodes, choose out the best replications location in many copies combined with copy placement and copy management to reduce the file access time. The simulation results show that the proposed scheme compared with other algorithm has better performance in terms of average task execution time. 

  8. Semantic Concept Mining Based on Hierarchical Event Detection for Soccer Video Indexing

    Directory of Open Access Journals (Sweden)

    Maheshkumar H. Kolekar

    2009-10-01

    Full Text Available In this paper, we present a novel automated indexing and semantic labeling for broadcast soccer video sequences. The proposed method automatically extracts silent events from the video and classifies each event sequence into a concept by sequential association mining. The paper makes three new contributions in multimodal sports video indexing and summarization. First, we propose a novel hierarchical framework for soccer (football video event sequence detection and classification. Unlike most existing video classification approaches, which focus on shot detection followed by shot-clustering for classification, the proposed scheme perform a top-down video scene classification which avoids shot clustering. This improves the classification accuracy and also maintains the temporal order of shots. Second, we compute the association for the events of each excitement clip using a priori mining algorithm. We propose a novel sequential association distance to classify the association of the excitement clip into semantic concepts. For soccer video, we have considered goal scored by team-A, goal scored by team-B, goal saved by team-A, goal saved by team-B as semantic concepts. Third, the extracted excitement clips with semantic concept label helps us to summarize many hours of video to collection of soccer highlights such as goals, saves, corner kicks, etc. We show promising results, with correctly indexed soccer scenes, enabling structural and temporal analysis, such as video retrieval, highlight extraction, and video skimming.

  9. Effect of aqueous electrolytes on the electrochemical behaviors of supercapacitors based on hierarchically porous carbons

    Science.gov (United States)

    Zhang, Xiaoyan; Wang, Xianyou; Jiang, Lanlan; Wu, Hao; Wu, Chun; Su, Jingcang

    2012-10-01

    Hierarchically porous carbons (HPCs) have been prepared by sol-gel self-assembly technology with nickel oxide and surfactant as the dual template. The porous carbons are further activated by nitric acid. The electrochemical behaviors of supercapacitors using HPCs as electrode material in different aqueous electrolytes, e.g., (NH4)2SO4, Na2SO4, H2SO4 and KOH are studied by cyclic voltametry, galvanostatic charge/discharge, cyclic life, leakage current, self-discharge and electrochemical impedance spectroscopy. The results demonstrate that the supercapacitors in various electrolytes perform definitely capacitive behaviors; especially in 6 M KOH electrolyte the supercapacitor represents the best electrochemical performance, the shortest relaxation time, and nearly ideal polarisability. The energy density of 8.42 Wh kg-1 and power density of 17.22 kW kg-1 are obtained at the operated voltage window of 1.0 V. Especially, the energy density of 11.54 Wh kg-1 and power density of 10.58 kW kg-1 can be achieved when the voltage is up to 1.2 V.

  10. A novel 300 kW arc plasma inverter system based on hierarchical controlled building block structure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To date, the high power arc plasma technology is widely used. A next generation high power arc plasma system based on building block structure is presented. The whole arc plasma inverter system is composed of 12 paralleled units to increase the system output capability. The hierarchical control system is adopted to improve the reliability and flexibility of the high power arc plasma inverter. To ensure the reliable turn on and off of the IGBT module in each building block unit, a special pulse drive circuit is designed by using pulse transformer. The experimental result indicates that the high power arc plasma inverter system can transfer 300 kW arc plasma energy reliably with high efficiency.

  11. Evaluation of B2C website based on the usability factors by using fuzzy AHP & hierarchical fuzzy TOPSIS

    Science.gov (United States)

    Masudin, I.; Saputro, T. E.

    2016-02-01

    In today's technology, electronic trading transaction via internet has been utilized properly with rapid growth. This paper intends to evaluate related to B2C e-commerce website in order to find out the one which meets the usability factors better than another. The influential factors to B2C e-commerce website are determined for two big retailer websites. The factors are investigated based on the consideration of several studies and conformed to the website characteristics. The evaluation is conducted by using different methods namely fuzzy AHP and hierarchical fuzzy TOPSIS so that the final evaluation can be compared. Fuzzy triangular number is adopted to deal with imprecise judgment under fuzzy environment.

  12. Recombination reduction on lead halide perovskite solar cells based on low temperature synthesized hierarchical TiO2 nanorods

    Science.gov (United States)

    Jaramillo-Quintero, Oscar A.; Solís de La Fuente, Mauricio; Sanchez, Rafael S.; Recalde, Ileana B.; Juarez-Perez, Emilio J.; Rincón, Marina E.; Mora-Seró, Iván

    2016-03-01

    Intensive research on the electron transport material (ETM) has been pursued to improve the efficiency of perovskite solar cells (PSCs) and decrease their cost. More importantly, the role of the ETM layer is not yet fully understood, and research on new device architectures is still needed. Here, we report the use of three-dimensional (3D) TiO2 with a hierarchical architecture based on rutile nanorods (NR) as photoanode material for PSCs. The proposed hierarchical nanorod (HNR) films were synthesized by a two-step low temperature (180 °C) hydrothermal method, and consist of TiO2 nanorod trunks with optimal lengths of 540 nm and TiO2 nanobranches with lengths of 45 nm. Different device configurations were fabricated with TiO2 structures (compact layer, NR and HNR) and CH3NH3PbI3, using different synthetic routes, as the active material. PSCs based on HNR-CH3NH3PbI3 achieved the highest power conversion efficiency compared to PSCs with other TiO2 structures. This result can be ascribed mainly to lower charge recombination as determined by impedance spectroscopy. Furthermore, we have observed that the CH3NH3PbI3 perovskite deposited by the two-step route shows higher efficiency, surface coverage and infiltration within the structure of 3D HNR than the one-step CH3NH3PbI3-xClx perovskite.Intensive research on the electron transport material (ETM) has been pursued to improve the efficiency of perovskite solar cells (PSCs) and decrease their cost. More importantly, the role of the ETM layer is not yet fully understood, and research on new device architectures is still needed. Here, we report the use of three-dimensional (3D) TiO2 with a hierarchical architecture based on rutile nanorods (NR) as photoanode material for PSCs. The proposed hierarchical nanorod (HNR) films were synthesized by a two-step low temperature (180 °C) hydrothermal method, and consist of TiO2 nanorod trunks with optimal lengths of 540 nm and TiO2 nanobranches with lengths of 45 nm. Different

  13. Approximation of skewed interfaces with tensor-based model reduction procedures: Application to the reduced basis hierarchical model reduction approach

    Science.gov (United States)

    Ohlberger, Mario; Smetana, Kathrin

    2016-09-01

    In this article we introduce a procedure, which allows to recover the potentially very good approximation properties of tensor-based model reduction procedures for the solution of partial differential equations in the presence of interfaces or strong gradients in the solution which are skewed with respect to the coordinate axes. The two key ideas are the location of the interface either by solving a lower-dimensional partial differential equation or by using data functions and the subsequent removal of the interface of the solution by choosing the determined interface as the lifting function of the Dirichlet boundary conditions. We demonstrate in numerical experiments for linear elliptic equations and the reduced basis-hierarchical model reduction approach that the proposed procedure locates the interface well and yields a significantly improved convergence behavior even in the case when we only consider an approximation of the interface.

  14. Hierarchical hybrid control network design based on LON and master-slave RS-422/485 protocol

    Institute of Scientific and Technical Information of China (English)

    彭可; 陈际达; 陈岚

    2002-01-01

    Aiming at the weaknesses of LON bus, combining the coexistence of fieldbus and DCS (Distribu-ted Control Systems) in control networks, the authors introduce a hierarchical hybrid control network design based on LON and master-slave RS-422/485 protocol. This design adopts LON as the trunk, master-slave RS-422/485 control networks are connected to LON as special subnets by dedicated gateways. It is an implementation method for isomerous control network integration. Data management is ranked according to real-time requirements for different network data. The core components, such as control network nodes, router and gateway, are detailed in the paper. The design utilizes both communication advantage of LonWorks technology and the more powerful control ability of universal MCUs or PLCs, thus it greatly increases system response speed and performance-cost ratio.

  15. Hierarchical clustering for graph visualization

    CERN Document Server

    Clémençon, Stéphan; Rossi, Fabrice; Tran, Viet Chi

    2012-01-01

    This paper describes a graph visualization methodology based on hierarchical maximal modularity clustering, with interactive and significant coarsening and refining possibilities. An application of this method to HIV epidemic analysis in Cuba is outlined.

  16. Modeling hierarchical structures - Hierarchical Linear Modeling using MPlus

    CERN Document Server

    Jelonek, M

    2006-01-01

    The aim of this paper is to present the technique (and its linkage with physics) of overcoming problems connected to modeling social structures, which are typically hierarchical. Hierarchical Linear Models provide a conceptual and statistical mechanism for drawing conclusions regarding the influence of phenomena at different levels of analysis. In the social sciences it is used to analyze many problems such as educational, organizational or market dilemma. This paper introduces the logic of modeling hierarchical linear equations and estimation based on MPlus software. I present my own model to illustrate the impact of different factors on school acceptation level.

  17. Hierarchical distance-based fuzzy approach to evaluate urban water supply systems in a semi-arid region.

    Science.gov (United States)

    Yekta, Tahereh Sadeghi; Khazaei, Mohammad; Nabizadeh, Ramin; Mahvi, Amir Hossein; Nasseri, Simin; Yari, Ahmad Reza

    2015-01-01

    Hierarchical distance-based fuzzy multi-criteria group decision making was served as a tool to evaluate the drinking water supply systems of Qom, a semi-arid city located in central part of Iran. A list of aspects consisting of 6 criteria and 35 sub-criteria were evaluated based on a linguistic term set by five decision-makers. Four water supply alternatives including "Public desalinated distribution system", "PET Bottled Drinking Water", "Private desalinated water suppliers" and "Household desalinated water units" were assessed based on criteria and sub-criteria. Data were aggregated and normalized to apply Performance Ratings of Alternatives. Also, the Performance Ratings of Alternatives were aggregated again to achieve the Aggregate Performance Ratings. The weighted distances from ideal solution and anti-ideal solution were calculated after secondary normalization. The proximity of each alternative to the ideal solution was determined as the final step. The alternatives were ranked based on the magnitude of ideal solutions. Results showed that "Public desalinated distribution system" was the most appropriate alternative to supply the drinking needs of Qom population. Also, "PET Bottled Drinking Water" was the second acceptable option. A novel classification of alternatives to satisfy the drinking water requirements was proposed which is applicable for the other cities located in semi-arid regions of Iran. The health issues were considered as independent criterion, distinct from the environmental issues. The constraints of high-tech alternatives were also considered regarding to the level of dependency on overseas. PMID:26221535

  18. MAP-Based Underdetermined Blind Source Separation of Convolutive Mixtures by Hierarchical Clustering and ℓ1-Norm Minimization

    Directory of Open Access Journals (Sweden)

    Hiroshi Sawada

    2007-01-01

    Full Text Available We address the problem of underdetermined BSS. While most previous approaches are designed for instantaneous mixtures, we propose a time-frequency-domain algorithm for convolutive mixtures. We adopt a two-step method based on a general maximum a posteriori (MAP approach. In the first step, we estimate the mixing matrix based on hierarchical clustering, assuming that the source signals are sufficiently sparse. The algorithm works directly on the complex-valued data in the time-frequency domain and shows better convergence than algorithms based on self-organizing maps. The assumption of Laplacian priors for the source signals in the second step leads to an algorithm for estimating the source signals. It involves the ℓ1-norm minimization of complex numbers because of the use of the time-frequency-domain approach. We compare a combinatorial approach initially designed for real numbers with a second-order cone programming (SOCP approach designed for complex numbers. We found that although the former approach is not theoretically justified for complex numbers, its results are comparable to, or even better than, the SOCP solution. The advantage is a lower computational cost for problems with low input/output dimensions.

  19. Hierarchical Self-Assembly of a Biomimetic Light-Harvesting Antenna Based on DNA G-Quadruplexes

    NARCIS (Netherlands)

    Oltra, Nuria Sancho; Browne, Wesley R.; Roelfes, Gerard

    2013-01-01

    A new modular approach to an artificial light-harvesting antenna system is presented. The approach involves the hierarchical self-assembly of porphyrin acceptor molecules to G-quadruplexes tethered to coumarin donor moieties.

  20. A novel vehicle dynamics stability control algorithm based on the hierarchical strategy with constrain of nonlinear tyre forces

    Science.gov (United States)

    Li, Liang; Jia, Gang; Chen, Jie; Zhu, Hongjun; Cao, Dongpu; Song, Jian

    2015-08-01

    Direct yaw moment control (DYC), which differentially brakes the wheels to produce a yaw moment for the vehicle stability in a steering process, is an important part of electric stability control system. In this field, most control methods utilise the active brake pressure with a feedback controller to adjust the braked wheel. However, the method might lead to a control delay or overshoot because of the lack of a quantitative project relationship between target values from the upper stability controller to the lower pressure controller. Meanwhile, the stability controller usually ignores the implementing ability of the tyre forces, which might be restrained by the combined-slip dynamics of the tyre. Therefore, a novel control algorithm of DYC based on the hierarchical control strategy is brought forward in this paper. As for the upper controller, a correctional linear quadratic regulator, which not only contains feedback control but also contains feed forward control, is introduced to deduce the object of the stability yaw moment in order to guarantee the yaw rate and side-slip angle stability. As for the medium and lower controller, the quantitative relationship between the vehicle stability object and the target tyre forces of controlled wheels is proposed to achieve smooth control performance based on a combined-slip tyre model. The simulations with the hardware-in-the-loop platform validate that the proposed algorithm can improve the stability of the vehicle effectively.

  1. Deterministic hierarchical networks

    Science.gov (United States)

    Barrière, L.; Comellas, F.; Dalfó, C.; Fiol, M. A.

    2016-06-01

    It has been shown that many networks associated with complex systems are small-world (they have both a large local clustering coefficient and a small diameter) and also scale-free (the degrees are distributed according to a power law). Moreover, these networks are very often hierarchical, as they describe the modularity of the systems that are modeled. Most of the studies for complex networks are based on stochastic methods. However, a deterministic method, with an exact determination of the main relevant parameters of the networks, has proven useful. Indeed, this approach complements and enhances the probabilistic and simulation techniques and, therefore, it provides a better understanding of the modeled systems. In this paper we find the radius, diameter, clustering coefficient and degree distribution of a generic family of deterministic hierarchical small-world scale-free networks that has been considered for modeling real-life complex systems.

  2. Joshua 6: A phrase-based and hierarchical statistical machine translation system

    Directory of Open Access Journals (Sweden)

    Post Matt

    2015-10-01

    Full Text Available We describe the version six release of Joshua, an open-source statistical machine translation toolkit. The main difference from release five is the introduction of a simple, unlexicalized, phrase-based stack decoder. This phrase-based decoder shares a hypergraph format with the syntax-based systems, permitting a tight coupling with the existing codebase of feature functions and hypergraph tools. Joshua 6 also includes a number of large-scale discriminative tuners and a simplified sparse feature function interface with reflection-based loading, which allows new features to be used by writing a single function. Finally, Joshua includes a number of simplifications and improvements focused on usability for both researchers and end-users, including the release of language packs — precompiled models that can be run as black boxes.

  3. Content-Based Hierarchical Analysis of News Video Using Audio and Visual Information

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A schema for content-based analysis of broadcast news video is presented. First, we separate commercials from news using audiovisual features. Then, we automatically organize news programs into a content hierarchy at various levels of abstraction via effective integration of video, audio, and text data available from the news programs. Based on these news video structure and content analysis technologies, a TV news video Library is generated, from which users can retrieve definite news story according to their demands.

  4. Hierarchical image enhancement

    Science.gov (United States)

    Qi, Wei; Han, Jing; Zhang, Yi; Bai, Lian-fa

    2016-05-01

    Image enhancement is an important technique in computer vision. In this paper, we propose a hierarchical image enhancement approach based on the structure layer and texture layer. In the structure layer, we propose a structure-based method based on GMM, which better exploits structure details with fewer noise. In the texture layer, we present a structure-filtering method to filter unwanted texture with keeping completeness of detected salient structure. Next, we introduce a structure constraint prior to integrate them, leading to an improved enhancement result. Extensive experiments demonstrate that the proposed approach achieves higher quality results than previous approaches.

  5. An Improved Particle Swarm Optimization Based on Deluge Approach for Enhanced Hierarchical Cache Optimization in IPTV Networks

    Directory of Open Access Journals (Sweden)

    M. Somu

    2014-05-01

    Full Text Available In recent years, IP network has been considered as a new delivery network for TV services. A majority of the telecommunication industries have used IP network to offer on-demand services and linear TV services as it can offer a two-way and high-speed communication. In order to effectively and economically utilize the IP network, caching is the technique which is usually preferred. In IPTV system, a managed network is utilized to bring out TV services, the requests of Video on Demand (VOD objects are usually combined in a limited period intensively and user preferences are fluctuated dynamically. Furthermore, the VOD content updates often under the control of IPTV providers. In order to minimize this traffic and overall network cost, a segment of the video content is stored in caches closer to subscribers, for example, Digital Subscriber Line Access Multiplexer (DSLAM, a Central Office (CO and Intermediate Office (IO. The major problem focused in this approach is to determine the optimal cache memory that should be assigned in order to attain maximum cost effectiveness. This approach uses an effective Grate Deluge algorithm based Particle Swarm Optimization (GDPSO approach for attaining the optimal cache memory size which in turn minimizes the overall network cost. The analysis shows that hierarchical distributed caching can save significant network cost through the utilization of the GDPSO algorithm.

  6. Hierarchical phrase-based grammatical analysis of language samples from Cantonese-speaking children with and without autism.

    Science.gov (United States)

    Leung, Man-Tak; Li, Hong-Lan

    2015-01-01

    The present study made a reference to Zhu Dexi's phrase-based grammar approach to analyse Cantonese utterances hierarchically into 14 syntactic structures (SS). A total of 68 speech samples from Cantonese-speaking children with and without Autism Spectrum Disorder (ASD) were collected. The mean length of utterance in words (MLUw), the number of syntactic structures (NOSS), the number of different syntactic structures (NODSS) and the flexibility of syntactic structures (FSS) of the samples were calculated. Comparisons among four groups of typically developing (TD) children revealed that all the indexes show developmental changes across age stages. Comparisons between ASD subjects and their age-matched (AM) and MLUw-matched (MM) normal peers were done. MLUw, NOSS and NODSS and FSS could be used to distinguish autistic children from their AM normal peers, but only FSS could be used to distinguish ASD from MM groups qualitatively and quantitatively. The lack of production of SP, V1O/SV2 and Coord1Coord2 with low FSS may be one of the factors that will affect ASD children's further syntactic development. PMID:26114755

  7. Enhanced cellular activities of polycaprolactone/alginate-based cell-laden hierarchical scaffolds for hard tissue engineering applications.

    Science.gov (United States)

    Lee, HyeongJin; Kim, GeunHyung

    2014-09-15

    Biomedical scaffolds have been widely investigated because they are essential for support and promotion of cell adhesion, proliferation and differentiation in three-dimensional (3D) structures. An ideal scaffold should be highly porous to enable efficient nutrient and oxygen transfer and have a 3D structure that provides optimal micro-environmental conditions for the seeded cells to obtain homogeneous growth after a long culture period. In this study, new hierarchical osteoblast-like cell (MG-63)-laden scaffolds consisting of micro-sized struts/inter-layered micro-nanofibres and cell-laden hydrogel struts with mechanically stable and biologically superior properties were introduced. Poly(ethylene oxide) (PEO) was used as a sacrificial component to generate pores within the cell-laden hydrogel struts to attain a homogeneous cell distribution and rapid cell growth in the scaffold interior. The alginate-based cell-laden struts with PEO induced fast/homogeneous cell release, in contrast to nonporous cell-laden struts. Various weight fractions (0.5, 1, 2, 3 and 3.5 wt%) of PEO were used, of which 2 wt% PEO in the cell-laden strut resulted in the most appropriate cell release and enhanced biological activities (cell proliferation and calcium deposition), compared to nonporous cell-laden struts. PMID:24974244

  8. Mapping Rule-Based And Stochastic Constraints To Connection Architectures: Implication For Hierarchical Image Processing

    Science.gov (United States)

    Miller, Michael I.; Roysam, Badrinath; Smith, Kurt R.

    1988-10-01

    Essential to the solution of ill posed problems in vision and image processing is the need to use object constraints in the reconstruction. While Bayesian methods have shown the greatest promise, a fundamental difficulty has persisted in that many of the available constraints are in the form of deterministic rules rather than as probability distributions and are thus not readily incorporated as Bayesian priors. In this paper, we propose a general method for mapping a large class of rule-based constraints to their equivalent stochastic Gibbs' distribution representation. This mapping allows us to solve stochastic estimation problems over rule-generated constraint spaces within a Bayesian framework. As part of this approach we derive a method based on Langevin's stochastic differential equation and a regularization technique based on the classical autologistic transfer function that allows us to update every site simultaneously regardless of the neighbourhood structure. This allows us to implement a completely parallel method for generating the constraint sets corresponding to the regular grammar languages on massively parallel networks. We illustrate these ideas by formulating the image reconstruction problem based on a hierarchy of rule-based and stochastic constraints, and derive a fully parallelestimator structure. We also present results computed on the AMT DAP500 massively parallel digital computer, a mesh-connected 32x32 array of processing elements which are configured in a Single-Instruction, Multiple Data stream architecture.

  9. A CAD System for Identification and Classification of Breast Cancer Tumors in DCE-MR Images Based on Hierarchical Convolutional Neural Networks

    Directory of Open Access Journals (Sweden)

    Reza Rastiboroujeni

    2015-06-01

    Full Text Available In this paper, we propose a computer aided diagnosis (CAD system based on hierarchical convolutional neural networks (HCNNs to discriminate between malignant and benign tumors in breast DCE-MRIs. A HCNN is a hierarchical neural network that operates on two-dimensional images. A HCNN integrates feature extraction and classification processes into one single and fully adaptive structure. It can extract two-dimensional key features automatically, and it is relatively tolerant to geometric and local distortions in input images. We evaluate CNN implementation learning and testing processes based on gradient descent (GD and resilient back-propagation (RPROP approaches. We show that, proposed HCNN with RPROP learning approach provide an effective and robust neural structure to design a CAD base system for breast MRI, and has potential as a mechanism for the evaluation of different types of abnormalities in medical images.

  10. Systems of Systems Modeled by a Hierarchical Part-Whole State-Based Formalism

    Directory of Open Access Journals (Sweden)

    Luca Pazzi

    2013-11-01

    Full Text Available The paper presents an explicit state-based modeling approach aimed at modeling Systems of Systems behavior. The approach allows to specify and verify incrementally safety and liveness rules without using model checking techniques. The state-based approach allows moreover to use the system behavior directly as an interface, greatly improving the effectiveness of the recursive composition needed when assembling Systems of Systems. Such systems are, at the same time, both parts and wholes, thus giving a formal characterization to the notion of Holon.

  11. Game Immersion Experience: Its Hierarchical Structure and Impact on Game-Based Science Learning

    Science.gov (United States)

    Cheng, M.-T.; She, H.-C.; Annetta, L. A.

    2015-01-01

    Many studies have shown the positive impact of serious educational games (SEGs) on learning outcomes. However, there still exists insufficient research that delves into the impact of immersive experience in the process of gaming on SEG-based science learning. The dual purpose of this study was to further explore this impact. One purpose was to…

  12. Edge Crossing Minimization Algorithm for Hierarchical Graphs Based on Genetic Algorithms

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We present an edge crossing minimization algorithm forhierarchical gr aphs based on genetic algorithms, and comparing it with some heuristic algorithm s. The proposed algorithm is more efficient and has the following advantages: th e frame of the algorithms is unified, the method is simple, and its implementati on and revision are easy.

  13. Lamellar Microdomains of Block-Copolymer-Based Ionic Supramolecules Exhibiting a Hierarchical Self-Assembly

    DEFF Research Database (Denmark)

    Ayoubi, Mehran Asad; Almdal, Kristoffer; Zhu, Kaizheng;

    2014-01-01

    Based on a parent diblock copolymer of poly(styrene)-b-poly(methacrylic acid), PS-b-PMAA, linear-b-amphiphilic comb (L-b-AC) ionic supramolecules [Soft Matter 2013, 9, 1540-1555] are synthesized in which the poly(methacrylate) backbone of the ionic supramolecular AC-block is neutralized by alkyl...

  14. Hierarchical online appearance-based tracking for 3D head pose, eyebrows, lips, eyelids, and irises

    NARCIS (Netherlands)

    Orozco, Javier; Rudovic, Ognjen; Gonzalez Garcia, Jordi; Pantic, Maja

    2013-01-01

    In this paper, we propose an On-line Appearance-Based Tracker (OABT) for simultaneous tracking of 3D head pose, lips, eyebrows, eyelids and irises in monocular video sequences. In contrast to previously proposed tracking approaches, which deal with face and gaze tracking separately, our OABT can als

  15. Modified distance in average linkage based on M-estimator and MADn criteria in hierarchical cluster analysis

    Science.gov (United States)

    Muda, Nora; Othman, Abdul Rahman

    2015-10-01

    The process of grouping a set of objects into classes of similar objects is called clustering. It divides a large group of observations into smaller groups so that the observations within each group are relatively similar and the observations in different groups are relatively dissimilar. In this study, an agglomerative method in hierarchical cluster analysis is chosen and clusters were constructed by using an average linkage technique. An average linkage technique requires distance between clusters, which is calculated based on the average distance between all pairs of points, one group with another group. In calculating the average distance, the distance will not be robust when there is an outlier. Therefore, the average distance in average linkage needs to be modified in order to overcome the problem of outlier. Therefore, the criteria of outlier detection based on MADn criteria is used and the average distance is recalculated without the outlier. Next, the distance in average linkage is calculated based on a modified one step M-estimator (MOM). The groups of cluster are presented in dendrogram graph. To evaluate the goodness of a modified distance in the average linkage clustering, the bootstrap analysis is conducted on the dendrogram graph and the bootstrap value (BP) are assessed for each branch in dendrogram that formed the group, to ensure the reliability of the branches constructed. This study found that the average linkage technique with modified distance is significantly superior than the usual average linkage technique, if there is an outlier. Both of these techniques are said to be similar if there is no outlier.

  16. Correspondence Analysis and Hierarchical Indexing For Content-Based Image Retrieval

    OpenAIRE

    Milanese, Ruggero; Squire, David; Pun, Thierry

    1996-01-01

    This paper describes a two-stage statistical approach supporting content-based search in image databases. The first stage performs correspondence analysis, a factor analysis method transforming image attributes into a reduced-size, uncorrelated factor space. The second stage performs ascendant heirarchical classification, an iterative clustering method which constructs a heirarchical index structure for the images of the database. Experimental results supporting the applicability of both tech...

  17. Hierarchical Modeling of Mastic Asphalt in Layered Road Structures Based on the Mori-Tanaka Method

    OpenAIRE

    Richard Valenta; Michal Šejnoha

    2012-01-01

    We present an application of the Mori-Tanaka micromechanical model for a description of the highly nonlinear behavior of asphalt mixtures. This method is expected to replace an expensive finite element-based fully-coupled multi-scale analysis while still providing useful information about local fields on the meso-scale that are not predictable by strictly macroscopic simulations. Drawing on our recent results from extensive experimental and also numerical investigations this paper concentrate...

  18. Enabling Sustainability: Hierarchical Need-Based Framework for Promoting Sustainable Data Infrastructure in Developing Countries

    OpenAIRE

    David O. Yawson; Frederick A. Armah; Alex N. M. Pappoe

    2009-01-01

    The paper presents thoughts on Sustainable Data Infrastructure (SDI) development, and its user requirements bases. It brings Maslow's motivational theory to the fore, and proposes it as a rationalization mechanism for entities (mostly governmental) that aim at realizing SDI. Maslow's theory, though well-known, is somewhat new in geospatial circles; this is where the novelty of the paper resides. SDI has been shown to enable and aid development in diverse ways. However, stimulating developing ...

  19. Collaborative Ensemble Learning: Combining Collaborative and Content-Based Information Filtering via Hierarchical Bayes

    OpenAIRE

    Yu, Kai; Schwaighofer, Anton; Tresp, Volker; Ma, Wei-Ying; Zhang, Hongjiang

    2012-01-01

    Collaborative filtering (CF) and content-based filtering (CBF) have widely been used in information filtering applications. Both approaches have their strengths and weaknesses which is why researchers have developed hybrid systems. This paper proposes a novel approach to unify CF and CBF in a probabilistic framework, named collaborative ensemble learning. It uses probabilistic SVMs to model each user's profile (as CBF does).At the prediction phase, it combines a society OF users profiles, rep...

  20. Water Extraction in High Resolution Remote Sensing Image Based on Hierarchical Spectrum and Shape Features

    International Nuclear Information System (INIS)

    This paper addresses the problem of water extraction from high resolution remote sensing images (including R, G, B, and NIR channels), which draws considerable attention in recent years. Previous work on water extraction mainly faced two difficulties. 1) It is difficult to obtain accurate position of water boundary because of using low resolution images. 2) Like all other image based object classification problems, the phenomena of ''different objects same image'' or ''different images same object'' affects the water extraction. Shadow of elevated objects (e.g. buildings, bridges, towers and trees) scattered in the remote sensing image is a typical noise objects for water extraction. In many cases, it is difficult to discriminate between water and shadow in a remote sensing image, especially in the urban region. We propose a water extraction method with two hierarchies: the statistical feature of spectral characteristic based on image segmentation and the shape feature based on shadow removing. In the first hierarchy, the Statistical Region Merging (SRM) algorithm is adopted for image segmentation. The SRM includes two key steps: one is sorting adjacent regions according to a pre-ascertained sort function, and the other one is merging adjacent regions based on a pre-ascertained merging predicate. The sort step is done one time during the whole processing without considering changes caused by merging which may cause imprecise results. Therefore, we modify the SRM with dynamic sort processing, which conducts sorting step repetitively when there is large adjacent region changes after doing merging. To achieve robust segmentation, we apply the merging region with six features (four remote sensing image bands, Normalized Difference Water Index (NDWI), and Normalized Saturation-value Difference Index (NSVDI)). All these features contribute to segment image into region of object. NDWI and NSVDI are discriminate between water and

  1. Property Networks Allowing Oracle-based Mode-change Propagation in Hierarchical Components

    Czech Academy of Sciences Publication Activity Database

    Pop, T.; Plášil, F.; Outlý, M.; Malohlava, M.; Bureš, Tomáš

    New York: ACM, 2012, s. 93-102. ISBN 978-1-4503-1345-2. [CBSE 2012. International ACM SIGSOFT Symposium on Component-Based Software Engineering /15./. Bertinoro (IT), 26.06.2012-28.06.2012] R&D Projects: GA ČR GD201/09/H057 EU Projects: European Commission(XE) ASCENS 257414 Grant ostatní: GA AV ČR(CZ) GAP202/11/0312; GA UK(CZ) 378111 Institutional support: RVO:67985807 Keywords : embedded - system s * real - time system s * software variability * modes for software architectures * change propagation * SOFA Subject RIV: JC - Computer Hardware ; Software

  2. Anisotropic mesh adaptation for solution of finite element problems using hierarchical edge-based error estimates

    Energy Technology Data Exchange (ETDEWEB)

    Lipnikov, Konstantin [Los Alamos National Laboratory; Agouzal, Abdellatif [UNIV DE LYON; Vassilevski, Yuri [Los Alamos National Laboratory

    2009-01-01

    We present a new technology for generating meshes minimizing the interpolation and discretization errors or their gradients. The key element of this methodology is construction of a space metric from edge-based error estimates. For a mesh with N{sub h} triangles, the error is proportional to N{sub h}{sup -1} and the gradient of error is proportional to N{sub h}{sup -1/2} which are optimal asymptotics. The methodology is verified with numerical experiments.

  3. Hierarchical online appearance-based tracking for 3D head pose, eyebrows, lips, eyelids, and irises

    OpenAIRE

    Orozco, Javier; Rudovic, Ognjen; Gonzàlez, Jordi; Pantic, Maja

    2013-01-01

    In this paper, we propose an On-line Appearance-Based Tracker (OABT) for simultaneous tracking of 3D head pose, lips, eyebrows, eyelids and irises in monocular video sequences. In contrast to previously proposed tracking approaches, which deal with face and gaze tracking separately, our OABT can also be used for eyelid and iris tracking, as well as 3D head pose, lips and eyebrows facial actions tracking. Furthermore, our approach applies an on-line learning of changes in the appearance of the...

  4. Multi-hierarchical fuzzy judgment and nested dominance relation of rough set theory-based environmental risk evaluation for tailings reservoirs

    Institute of Scientific and Technical Information of China (English)

    田森; 陈建宏

    2015-01-01

    Environmental risk assessment of tailings reservoir assessment system is complex and has many index factors. In order to accurately judge surrounding environmental risks of tailings reservoirs and determinate the corresponding prevention and control work, multi-hierarchical fuzzy judgment and nested dominance relation of rough set theory are implemented to evaluate them and find out the rules of this evaluation system with 14 representative cases. The methods of multi-hierarchical fuzzy evaluation can overall consider each influence factor of risk assessment system and their mutual impact, and the index weight based on the analytic hierarchy process is relatively reasonable. Rough set theory based on dominance relation reduces each index attribute from the top down, largely simplifies the complexity of the original evaluation system, and considers the preferential information in each index. Furthermore, grey correlation theory is applied to analysis of importance of each reducted condition attribute. The results demonstrate the feasibility of the proposed safety evaluation system and the application potential.

  5. A repeatedly refuelable mediated biofuel cell based on a hierarchical porous carbon electrode

    Science.gov (United States)

    Fujita, Shuji; Yamanoi, Shun; Murata, Kenichi; Mita, Hiroki; Samukawa, Tsunetoshi; Nakagawa, Takaaki; Sakai, Hideki; Tokita, Yuichi

    2014-01-01

    Biofuel cells that generate electricity from renewable fuels, such as carbohydrates, must be reusable through repeated refuelling, should these devices be used in consumer electronics. We demonstrate the stable generation of electricity from a glucose-powered mediated biofuel cell through multiple refuelling cycles. This refuelability is achieved by immobilizing nicotinamide adenine dinucleotide (NAD), an electron-transfer mediator, and redox enzymes in high concentrations on porous carbon particles constituting an anode while maintaining their electrochemical and enzymatic activities after the immobilization. This bioanode can be refuelled continuously for more than 60 cycles at 1.5 mA cm−2 without significant potential drop. Cells assembled with these bioanodes and bilirubin-oxidase-based biocathodes can be repeatedly used to power a portable music player at 1 mW cm−3 through 10 refuelling cycles. This study suggests that the refuelability within consumer electronics should facilitate the development of long and repeated use of the mediated biofuel cells as well as of NAD-based biosensors, bioreactors, and clinical applications. PMID:24820210

  6. Study of a Comprehensive Assessment Method for Coal Mine Safety Based on a Hierarchical Grey Analysis

    Institute of Scientific and Technical Information of China (English)

    LIU Ya-jing; MAO Shan-jun; LI Mei; YAO Ji-ming

    2007-01-01

    Coal mine safety is a complex system, which is controlled by a number of interrelated factors and is difficult to estimate. This paper proposes an index system of safety assessment based on correlated factors involved in coal mining and a comprehensive evaluation model that combines the advantages of the AHP and a grey clustering method to guarantee the accuracy and objectivity of weight coefficients. First, we confirmed the weight of every index using the AHP, then did a general safety assessment by means of a grey clustering method. This model analyses the status of mining safety both qualitatively and quantitatively. It keeps management and technical groups informed of the situation of the coal production line in real time, which aids in making correct decisions based on practical safety issues. A case study in the application of the model is presented. The results show that the method is applicable and realistic with regard to the core of a coal mine's safety management. Consequently, the safe production of a mine and the awareness of advanced safe production management is accelerated.

  7. A repeatedly refuelable mediated biofuel cell based on a hierarchical porous carbon electrode

    Science.gov (United States)

    Fujita, Shuji; Yamanoi, Shun; Murata, Kenichi; Mita, Hiroki; Samukawa, Tsunetoshi; Nakagawa, Takaaki; Sakai, Hideki; Tokita, Yuichi

    2014-05-01

    Biofuel cells that generate electricity from renewable fuels, such as carbohydrates, must be reusable through repeated refuelling, should these devices be used in consumer electronics. We demonstrate the stable generation of electricity from a glucose-powered mediated biofuel cell through multiple refuelling cycles. This refuelability is achieved by immobilizing nicotinamide adenine dinucleotide (NAD), an electron-transfer mediator, and redox enzymes in high concentrations on porous carbon particles constituting an anode while maintaining their electrochemical and enzymatic activities after the immobilization. This bioanode can be refuelled continuously for more than 60 cycles at 1.5 mA cm-2 without significant potential drop. Cells assembled with these bioanodes and bilirubin-oxidase-based biocathodes can be repeatedly used to power a portable music player at 1 mW cm-3 through 10 refuelling cycles. This study suggests that the refuelability within consumer electronics should facilitate the development of long and repeated use of the mediated biofuel cells as well as of NAD-based biosensors, bioreactors, and clinical applications.

  8. Hierarchical architecture of active knits

    International Nuclear Information System (INIS)

    Nature eloquently utilizes hierarchical structures to form the world around us. Applying the hierarchical architecture paradigm to smart materials can provide a basis for a new genre of actuators which produce complex actuation motions. One promising example of cellular architecture—active knits—provides complex three-dimensional distributed actuation motions with expanded operational performance through a hierarchically organized structure. The hierarchical structure arranges a single fiber of active material, such as shape memory alloys (SMAs), into a cellular network of interlacing adjacent loops according to a knitting grid. This paper defines a four-level hierarchical classification of knit structures: the basic knit loop, knit patterns, grid patterns, and restructured grids. Each level of the hierarchy provides increased architectural complexity, resulting in expanded kinematic actuation motions of active knits. The range of kinematic actuation motions are displayed through experimental examples of different SMA active knits. The results from this paper illustrate and classify the ways in which each level of the hierarchical knit architecture leverages the performance of the base smart material to generate unique actuation motions, providing necessary insight to best exploit this new actuation paradigm. (paper)

  9. The neural substrates of drawing: a voxel-based morphometry analysis of constructional, hierarchical, and spatial representation deficits.

    Science.gov (United States)

    Chechlacz, Magdalena; Novick, Abigail; Rotshtein, Pia; Bickerton, Wai-Ling; Humphreys, Glyn W; Demeyere, Nele

    2014-12-01

    Deficits in the ability to draw objects, despite apparently intact perception and motor abilities, are defined as constructional apraxia. Constructional deficits, often diagnosed based on performance on copying complex figures, have been reported in a range of pathologies, perhaps reflecting the contribution of several underlying factors to poor figure drawing. The current study provides a comprehensive analysis of brain-behavior relationships in drawing disorders based on data from a large cohort of subacute stroke patients (n = 358) using whole-brain voxel-wise statistical analyses linked to behavioral measures from a complex figure copy task. We found that (i) overall poor performance on figure copying was associated with subcortical lesions (BG and thalamus), (ii) lateralized deficits with respect to the midline of the viewer were associated with lesions within the posterior parietal lobule, and (iii) spatial positioning errors across the entire figure were associated with lesions within visual processing areas (lingual gyrus and calcarine) and the insula. Furthermore, deficits in reproducing global aspects of form were associated with damage to the right middle temporal gyrus, whereas deficits in representing local features were linked to the left hemisphere lesions within calcarine cortex (extending into the cuneus and precuneus), the insula, and the TPJ. The current study provides strong evidence that impairments in separate cognitive mechanisms (e.g., spatial coding, attention, motor execution, and planning) linked to different brain lesions contribute to poor performance on complex figure copying tasks. The data support the argument that drawing depends on several cognitive processes operating via discrete neuronal networks and that constructional problems as well as hierarchical and spatial representation deficits contribute to poor figure copying. PMID:24893744

  10. "An Individual Level RF Analysis based on Consumer Behavior Theory: A Hierarchical Bayes Framework on the Pareto/NBD Model"(in Japanese)

    OpenAIRE

    Makoto Abe

    2007-01-01

    This research extends a Pareto/NBD model of customer-base analysis using a hierarchical Bayesian (HB) framework to suit today's customized marketing. The proposed HB model presumes three tried and tested assumptions of Pareto/NBD models: (1) a Poisson purchase process, (2) a memoryless dropout process (i.e., constant hazard rate), and (3) heterogeneity across customers, while relaxing the independence assumption of the purchase and dropout rates and incorporating customer characteristics as c...

  11. Hierarchical Modeling of Mastic Asphalt in Layered Road Structures Based on the Mori-Tanaka Method

    Directory of Open Access Journals (Sweden)

    Richard Valenta

    2012-01-01

    Full Text Available We present an application of the Mori-Tanaka micromechanical model for a description of the highly nonlinear behavior of asphalt mixtures. This method is expected to replace an expensive finite element-based fully-coupled multi-scale analysis while still providing useful information about local fields on the meso-scale that are not predictable by strictly macroscopic simulations. Drawing on our recent results from extensive experimental and also numerical investigations this paper concentrates on principal limitations of the Mori-Tanaka method, typical of all two-point averaging schemes, when appliedto material systems prone to evolving highly localized deformation patterns such as a network of shear bands. The inability of the Mori-Tanaka method to properly capture the correct stress transfer between phases with increasing compliance of the matrix phase is remedied here by introducing a damage like parameter into the local constitutive equation of reinforcements (stones to control an amount of stress taken by this phase. A deficiency of the Mori-Tanaka method in the prediction of creep response is also mentioned particularly in the light of large scale simulations. A comparison with the application of macroscopic homogenized constitutive model for an asphalt mixture is also presented.

  12. A MULTI TREE BASED APPROACH FOR PERFORMANCE ANALYSIS IN HIERARCHICAL WIRELESS SENSOR NETWORKS

    Directory of Open Access Journals (Sweden)

    Itu Snigdh

    2014-12-01

    Full Text Available A wireless sensor network consisting of heterogeneous sensors is capable of dealing with more than one type of information about any region at a time. Sensor applications that cater to disaster relief require faster data delivery and effective connectivity than the other monitoring applications. Moreover, usually, sensors collect a single type of data. Our approach focuses on generating a tree based communication architecture that is made up of three different types of sensors and ensures that at least one sensor of each type is connected to the communication backbone; thereby forming a MULTI-TREE. By responding to query initiated by the sink for one type of data at a time, the heterogeneous sensors ensure reduced amount of carried load and latency in data transmission. Our strategy implemented for structural health monitoring application shows that when compared to a minimum spanning tree under the same simulation constraints, performs better as it reduces the carried load and delay to one third under the existing set of ad hoc protocols.

  13. Supercapacitors Based on Three-Dimensional Hierarchical Graphene Aerogels with Periodic Macropores.

    Science.gov (United States)

    Zhu, Cheng; Liu, Tianyu; Qian, Fang; Han, T Yong-Jin; Duoss, Eric B; Kuntz, Joshua D; Spadaccini, Christopher M; Worsley, Marcus A; Li, Yat

    2016-06-01

    Graphene is an atomically thin, two-dimensional (2D) carbon material that offers a unique combination of low density, exceptional mechanical properties, thermal stability, large surface area, and excellent electrical conductivity. Recent progress has resulted in macro-assemblies of graphene, such as bulk graphene aerogels for a variety of applications. However, these three-dimensional (3D) graphenes exhibit physicochemical property attenuation compared to their 2D building blocks because of one-fold composition and tortuous, stochastic porous networks. These limitations can be offset by developing a graphene composite material with an engineered porous architecture. Here, we report the fabrication of 3D periodic graphene composite aerogel microlattices for supercapacitor applications, via a 3D printing technique known as direct-ink writing. The key factor in developing these novel aerogels is creating an extrudable graphene oxide-based composite ink and modifying the 3D printing method to accommodate aerogel processing. The 3D-printed graphene composite aerogel (3D-GCA) electrodes are lightweight, highly conductive, and exhibit excellent electrochemical properties. In particular, the supercapacitors using these 3D-GCA electrodes with thicknesses on the order of millimeters display exceptional capacitive retention (ca. 90% from 0.5 to 10 A·g(-1)) and power densities (>4 kW·kg(-1)) that equal or exceed those of reported devices made with electrodes 10-100 times thinner. This work provides an example of how 3D-printed materials, such as graphene aerogels, can significantly expand the design space for fabricating high-performance and fully integrable energy storage devices optimized for a broad range of applications. PMID:26789202

  14. Hierarchical self-assembly of switchable nucleolipid supramolecular gels based on environmentally-sensitive fluorescent nucleoside analogs

    Science.gov (United States)

    Nuthanakanti, Ashok; Srivatsan, Seergazhi G.

    2016-02-01

    Exquisite recognition and folding properties have rendered nucleic acids as useful supramolecular synthons for the construction of programmable architectures. Despite their proven applications in nanotechnology, scalability and fabrication of nucleic acid nanostructures still remain a challenge. Here, we describe a novel design strategy to construct new supramolecular nucleolipid synthons by using environmentally-sensitive fluorescent nucleoside analogs, based on 5-(benzofuran-2-yl)uracil and 5-(benzo[b]thiophen-2-yl)uracil cores, as the head group and fatty acids, attached to the ribose sugar, as the lipophilic group. These modified nucleoside-lipid hybrids formed organogels driven by hierarchical structures such as fibers, twisted ribbons, helical ribbons and nanotubes, which depended on the nature of fatty acid chain and nucleobase modification. NMR, single crystal X-ray and powder X-ray diffraction studies revealed the coordinated interplay of various non-covalent interactions invoked by modified nucleobase, sugar and fatty acid chains in setting up the pathway for the gelation process. Importantly, these nucleolipid gels retained or displayed aggregation-induced enhanced emission and their gelation behavior and photophysical properties could be reversibly switched by external stimuli such as temperature, ultrasound and chemicals. Furthermore, the switchable nature of nucleolipid gels to chemical stimuli enabled the selective two channel recognition of fluoride and Hg2+ ions through visual phase transition and fluorescence change. Fluorescent organogels exhibiting such a combination of useful features is rare, and hence, we expect that this innovative design of fluorescent nucleolipid supramolecular synthons could lead to the emergence of a new family of smart optical materials and probes.Exquisite recognition and folding properties have rendered nucleic acids as useful supramolecular synthons for the construction of programmable architectures. Despite their

  15. Hierarchical TiO2 flowers built from TiO2 nanotubes for efficient Pt-free based flexible dye-sensitized solar cells.

    Science.gov (United States)

    Lei, Bing-Xin; Luo, Qiu-Ping; Yu, Xiao-Yun; Wu, Wu-Qiang; Su, Cheng-Yong; Kuang, Dai-Bin

    2012-10-14

    A novel hierarchical TiO(2) flower consisting of anatase TiO(2) nanotubes on a Ti foil substrate has been prepared via a mild hydrothermal reaction of TiO(2) nanoparticles/Ti foil. The photovoltaic performance of DSSC based on hierarchical TiO(2) flowers/Ti (7.2%) is much higher than that of TiO(2) nanoparticle/Ti (6.63%) because of its superior light scattering ability and fast electron transport. Moreover, full flexible DSSC based on the novel hierarchical TiO(2) flowers/Ti foil photoelectrode and electrodeposited poly(3,4-ethylenedioxythiophene) (PEDOT) on indium tin oxide-coated poly(ethylene terephthalate) (ITO-PET) counter electrode shows a significant power conversion efficiency of 6.26%, accompanying a short-circuit current density of 11.96 mA cm(-2), an open-circuit voltage of 761 mV and a fill factor of 0.69. PMID:22914771

  16. Top-down feedback in an HMAX-like cortical model of object perception based on hierarchical Bayesian networks and belief propagation.

    Directory of Open Access Journals (Sweden)

    Salvador Dura-Bernal

    Full Text Available Hierarchical generative models, such as Bayesian networks, and belief propagation have been shown to provide a theoretical framework that can account for perceptual processes, including feedforward recognition and feedback modulation. The framework explains both psychophysical and physiological experimental data and maps well onto the hierarchical distributed cortical anatomy. However, the complexity required to model cortical processes makes inference, even using approximate methods, very computationally expensive. Thus, existing object perception models based on this approach are typically limited to tree-structured networks with no loops, use small toy examples or fail to account for certain perceptual aspects such as invariance to transformations or feedback reconstruction. In this study we develop a Bayesian network with an architecture similar to that of HMAX, a biologically-inspired hierarchical model of object recognition, and use loopy belief propagation to approximate the model operations (selectivity and invariance. Crucially, the resulting Bayesian network extends the functionality of HMAX by including top-down recursive feedback. Thus, the proposed model not only achieves successful feedforward recognition invariant to noise, occlusions, and changes in position and size, but is also able to reproduce modulatory effects such as illusory contour completion and attention. Our novel and rigorous methodology covers key aspects such as learning using a layerwise greedy algorithm, combining feedback information from multiple parents and reducing the number of operations required. Overall, this work extends an established model of object recognition to include high-level feedback modulation, based on state-of-the-art probabilistic approaches. The methodology employed, consistent with evidence from the visual cortex, can be potentially generalized to build models of hierarchical perceptual organization that include top-down and bottom

  17. Enhanced Deployment Strategy for Role-based Hierarchical Application Agents in Wireless Sensor Networks with Established Clusterheads

    Science.gov (United States)

    Gendreau, Audrey

    Efficient self-organizing virtual clusterheads that supervise data collection based on their wireless connectivity, risk, and overhead costs, are an important element of Wireless Sensor Networks (WSNs). This function is especially critical during deployment when system resources are allocated to a subsequent application. In the presented research, a model used to deploy intrusion detection capability on a Local Area Network (LAN), in the literature, was extended to develop a role-based hierarchical agent deployment algorithm for a WSN. The resulting model took into consideration the monitoring capability, risk, deployment distribution cost, and monitoring cost associated with each node. Changing the original LAN methodology approach to model a cluster-based sensor network depended on the ability to duplicate a specific parameter that represented the monitoring capability. Furthermore, other parameters derived from a LAN can elevate costs and risk of deployment, as well as jeopardize the success of an application on a WSN. A key component of the approach presented in this research was to reduce the costs when established clusterheads in the network were found to be capable of hosting additional detection agents. In addition, another cost savings component of the study addressed the reduction of vulnerabilities associated with deployment of agents to high volume nodes. The effectiveness of the presented method was validated by comparing it against a type of a power-based scheme that used each node's remaining energy as the deployment value. While available energy is directly related to the model used in the presented method, the study deliberately sought out nodes that were identified with having superior monitoring capability, cost less to create and sustain, and are at low-risk of an attack. This work investigated improving the efficiency of an intrusion detection system (IDS) by using the proposed model to deploy monitoring agents after a temperature sensing

  18. Hierarchical partial order ranking

    International Nuclear Information System (INIS)

    Assessing the potential impact on environmental and human health from the production and use of chemicals or from polluted sites involves a multi-criteria evaluation scheme. A priori several parameters are to address, e.g., production tonnage, specific release scenarios, geographical and site-specific factors in addition to various substance dependent parameters. Further socio-economic factors may be taken into consideration. The number of parameters to be included may well appear to be prohibitive for developing a sensible model. The study introduces hierarchical partial order ranking (HPOR) that remedies this problem. By HPOR the original parameters are initially grouped based on their mutual connection and a set of meta-descriptors is derived representing the ranking corresponding to the single groups of descriptors, respectively. A second partial order ranking is carried out based on the meta-descriptors, the final ranking being disclosed though average ranks. An illustrative example on the prioritisation of polluted sites is given. - Hierarchical partial order ranking of polluted sites has been developed for prioritization based on a large number of parameters

  19. Hierarchical topic modeling with nested hierarchical Dirichlet process

    Institute of Scientific and Technical Information of China (English)

    Yi-qun DING; Shan-ping LI; Zhen ZHANG; Bin SHEN

    2009-01-01

    This paper deals with the statistical modeling of latent topic hierarchies in text corpora. The height of the topic tree is assumed as fixed, while the number of topics on each level as unknown a priori and to be inferred from data. Taking a nonparametric Bayesian approach to this problem, we propose a new probabilistic generative model based on the nested hierarchical Dirichlet process (nHDP) and present a Markov chain Monte Carlo sampling algorithm for the inference of the topic tree structure as welt as the word distribution of each topic and topic distribution of each document. Our theoretical analysis and experiment results show that this model can produce a more compact hierarchical topic structure and captures more free-grained topic relationships compared to the hierarchical latent Dirichlet allocation model.

  20. Discovering hierarchical structure in normal relational data

    DEFF Research Database (Denmark)

    Schmidt, Mikkel Nørgaard; Herlau, Tue; Mørup, Morten

    2014-01-01

    Hierarchical clustering is a widely used tool for structuring and visualizing complex data using similarity. Traditionally, hierarchical clustering is based on local heuristics that do not explicitly provide assessment of the statistical saliency of the extracted hierarchy. We propose a non...

  1. Self-assembled Synthesis of 3D CuO Flocculus-like Nanosheet-based Hierarchical Nanostructures

    Institute of Scientific and Technical Information of China (English)

    YIN Yong-kui; XU Yan-Li; LI Ying; REN Feng-yun; LI Shuang-jing; JIN Ge; LI Miao-jing

    2013-01-01

    A simple,surfactant-free,and environmentally benign method has been developed to synthesize a novel 3D flocculus-like CuO hierarchical nanostructure self-assembled with 2D nanosheet as building blocks.Detailed proofs demonstrate that the overall synthetic process underwent the dehydration and re-crystallization of precursor Cu(OH)2 nanowires,and the subsequent two-step oriented attachment.In addition,3D butterfly-like and flower-like CuO nanostructures consisted of 2D nanosheets could be obtained by adjusting the concentration of NaOH(cNaOH) in the solution.cNaOH played a key role in tailoring the thickness of the nanosheets and changing the morphology of the product.This report may be helpful to constructing fine-tune hierarchical CuO nanostructures under basic conditions.

  2. New physiologically-relevant liver tissue model based on hierarchically cocultured primary rat hepatocytes with liver endothelial cells.

    Science.gov (United States)

    Xiao, Wenjin; Perry, Guillaume; Komori, Kikuo; Sakai, Yasuyuki

    2015-11-01

    To develop an in vitro liver tissue equivalent, hepatocytes should be cocultured with liver non-parenchymal cells to mimic the in vivo physiological microenvironments. In this work, we describe a physiologically-relevant liver tissue model by hierarchically organizing layers of primary rat hepatocytes and human liver sinusoidal endothelial cells (TMNK-1) on an oxygen-permeable polydimethylsiloxane (PDMS) membrane, which facilitates direct oxygenation by diffusion through the membrane. This in vivo-mimicking hierarchical coculture was obtained by simply proceeding the overlay of TMNK-1 cells on the hepatocyte layer re-formed on the collagen immobilized PDMS membranes. The comparison of hepatic functionalities was achieved between coculture and sandwich culture with Matrigel, in the presence and absence of direct oxygenation. A complete double-layered structure of functional liver cells with vertical contact between hepatocytes and TMNK-1 was successfully constructed in the coculture with direct oxygen supply and was well-maintained for 14 days. The hepatocytes in this hierarchical culture exhibited improved survival, functional bile canaliculi formation, cellular level polarization and maintenance of metabolic activities including Cyp1A1/2 activity and albumin production. By contrast, the two cell populations formed discontinuous monolayers on the same surfaces in the non-oxygen-permeable cultures. These results demonstrate that (i) the direct oxygenation through the PDMS membranes enables very simple formation of a hierarchical structure consisting of a hepatocyte layer and a layer of TMNK-1 and (ii) we may include other non-parenchymal cells in this format easily, which can be widely applicable to other epithelial organs. PMID:26304784

  3. Self-Assembly of Hierarchical Chiral Nanostructures Based on Metal-Benzimidazole Interactions: Chiral Nanofibers, Nanotubes, and Microtubular Flowers.

    Science.gov (United States)

    Zhou, Xiaoqin; Jin, Qingxian; Zhang, Li; Shen, Zhaocun; Jiang, Long; Liu, Minghua

    2016-09-01

    Controlled hierarchical self-assembly of synthetic molecules into chiral nanoarchitectures to mimic those biological chiral structures is of great importance. Here, a low-molecular-weight organogelator containing a benzimidazole moiety conjugated with an amphiphilic l-glutamic amide has been designed and its self-assembly into various hierarchical chiral nanostructures is investigated. Upon gel formation in organic solvents, 1D chiral nanostructure such as nanofiber and nanotube are obtained depending on the solvents. In the presence of transition and rare earth metal ions, hierarchical chiral nanostructures are formed. Specifically, the addition of TbCl3 , EuCl3 , and AgNO3 leads to nanofiber structures, while the addition of Cu(NO3 )2 , Tb(NO3 )3 , or Eu(NO3 )3 provides the microflower structures and microtubular flower structures, respectively. While Eu(III) and Tb(III)-containing microtubular flowers keep the chirality, the Cu(II)-coordinated microflowers lose chirality. More interestingly, the nanofibers formed by the gelator coordinated with Eu(III) or Tb(III) ions show not only the supramolecular chirality but also the circularly polarized luminescence. PMID:27248367

  4. Smart microgrid hierarchical frequency control ancillary service provision based on virtual inertia concept: An integrated demand response and droop controlled distributed generation framework

    International Nuclear Information System (INIS)

    Highlights: • Detailed formulation of the microgrid static and dynamic securities based on droop control and virtual inertia concepts. • Constructing a novel objective function using frequency excursion and rate of change of frequency profiles. • Ensuring the microgrid security subject to the microgrid economic and environmental policies. • Coordinated management of demand response and droop controlled distributed generation resources. • Precise scheduling of day-ahead hierarchical frequency control ancillary services using a scenario based stochastic programming. - Abstract: Low inertia stack, high penetration levels of renewable energy source and great ratio of power deviations in a small power delivery system put microgrid frequency at risk of instability. On the basis of the close coupling between the microgrid frequency and system security requirements, procurement of adequate ancillary services from cost-effective and environmental friendly resources is a great challenge requests an efficient energy management system. Motivated by this need, this paper presents a novel energy management system that is aimed to coordinately manage the demand response and distributed generation resources. The proposed approach is carried out by constructing a hierarchical frequency control structure in which the frequency dependent control functions of the microgrid components are modeled comprehensively. On the basis of the derived modeling, both the static and dynamic frequency securities of an islanded microgrid are provided in primary and secondary control levels. Besides, to cope with the low inertia stack of islanded microgrids, novel virtual inertia concept is devised based on the precise modeling of droop controlled distributed generation resources. The proposed approach is applied to typical test microgrid. Energy and hierarchical reserve resource are scheduled precisely using a scenario-based stochastic programming methodology. Moreover, analyzing the

  5. Incorporating Usability Criteria into the Development of Animated Hierarchical Maps

    Science.gov (United States)

    Shih, Yu-Cheng; Huang, Pei-Ren; Chen, Sherry Y.

    2013-01-01

    Nowadays, Web-based learning systems have become popular because they can provide multiple tools, among which hierarchical maps are widely used to support teaching and learning. However, traditional hierarchical maps may let learners easily get lost within large information space. This study proposes an animated hierarchical map to address this…

  6. Enhanced photovoltaic performance of fully flexible dye-sensitized solar cells based on the Nb2O5 coated hierarchical TiO2 nanowire-nanosheet arrays

    Science.gov (United States)

    Liu, Wenwu; Hong, Chengxun; Wang, Hui-gang; Zhang, Mei; Guo, Min

    2016-02-01

    Nb2O5 coated hierarchical TiO2 nanowire-sheet arrays photoanode was synthesized on flexible Ti-mesh substrate by using a hydrothermal approach. The effect of TiO2 morphology and Nb2O5 coating layer on the photovoltaic performance of the flexible dye sensitized solar cells (DSSCs) based on Ti-mesh supported nanostructures were systematically investigated. Compared to the TiO2 nanowire arrays (NWAs), hierarchical TiO2 nanowire arrays (HNWAs) with enlarged internal surface area and strong light scattering properties exhibited higher overall conversion efficiency. The introduction of thin Nb2O5 coating layers on the surface of the TiO2 HNWAs played a key role in improving the photovoltaic performance of the flexible DSSC. By separating the TiO2 and electrolyte (I-/I3-), the Nb2O5 energy barrier decreased the electron recombination rate and increased electron collection efficiency and injection efficiency, resulting in improved Jsc and Voc. Furthermore, the influence of Nb2O5 coating amounts on the power conversion efficiency were discussed in detail. The fully flexible DSSC based on Nb2O5 coated TiO2 HNWAs films with a thickness of 14 μm displayed a well photovoltaic property of 4.55% (Jsc = 10.50 mA cm-2, Voc = 0.75 V, FF = 0.58). The performance enhancement of the flexible DSSC is largely attributed to the reduced electron recombination, enlarged internal surface area and superior light scattering ability of the formed hierarchical nanostructures.

  7. Hierarchical Velocity Control Based on Differential Flatness for a DC/DC Buck Converter-DC Motor System

    OpenAIRE

    Silva-Ortigoza, R.; C. Márquez-Sánchez; F. Carrizosa-Corral; M. Antonio-Cruz; J. M. Alba-Martínez; Saldaña-González, G.

    2014-01-01

    This paper presents a hierarchical controller that carries out the angular velocity trajectory tracking task for a DC motor driven by a DC/DC Buck converter. The high level control is related to the DC motor and the low level control is dedicated to the DC/DC Buck converter; both controls are designed via differential flatness. The high level control provides a desired voltage profile for the DC motor to achieve the tracking of a desired angular velocity trajectory. Then, a low level control ...

  8. Shadow-Based Hierarchical Matching for the Automatic Registration of Airborne LiDAR Data and Space Imagery

    OpenAIRE

    Alireza Safdarinezhad; Mehdi Mokhtarzade; Mohammad Javad Valadan Zoej

    2016-01-01

    The automatic registration of LiDAR data and optical images, which are heterogeneous data sources, has been a major research challenge in recent years. In this paper, a novel hierarchical method is proposed in which the least amount of interaction of a skilled operator is required. Thereby, two shadow extraction schemes, one from LiDAR and the other from high-resolution satellite images, were used, and the obtained 2D shadow maps were then considered as prospective matching entities. Taken as...

  9. Hydrogen peroxide biosensor based on direct electrochemistry of hemoglobin immobilized on gold nanoparticles in a hierarchically porous zeolite

    International Nuclear Information System (INIS)

    Highly dispersed gold nanoparticles (AuNPs) were introduced into a hierarchically porous zeolite of the MFI type that contains mesopores and an inherently microporous structure. These represent a novel matrix for the immobilization of biomolecules. The composites were characterized by FTIR, X-ray diffraction, UV–vis spectroscopy, transmission electron microscopy, nitrogen sorption measurements, and electrochemical impedance spectroscopy. The crystallinity and morphology of the zeolite is not compromised by incorporating the AuNPs with their size of 3–20 nm. A sensor for hydrogen peroxide (H2O2) was fabricated by incorporating hemoglobin into the matrix and placing it on the surface of a glassy carbon electrode. The resulting biosensor exhibits excellent bioelectrocatalytic capability for the reduction of H2O2. The amperometric response at −0.4 V linearly depends on H2O2 in the 1.0 μM to 18 mM concentration range. The detection limit is 0.8 μM (at an S/N of 3). Its good sensitivity, stability and reproducibility make the modified hierarchically porous zeolite a promising new matrix material for protein immobilization and the construction of biosensors. (author)

  10. Three-dimensional beehive-like hierarchical porous polyacrylonitrile-based carbons as a high performance supercapacitor electrodes

    Science.gov (United States)

    Yao, Long; Yang, Guangzhi; Han, Pan; Tang, Zhihong; Yang, Junhe

    2016-05-01

    Three-dimensional beehive-like hierarchical porous carbons (HPCs) have been prepared by a facile carbonization of polymethylmethacrylate (PMMA)/polyacrylonitrile (PAN) core-shell polymer particle followed by KOH activation. The all-organic porogenic core-shell precursor was synthesized by a simple and green surfactant-free emulsion polymerization. The as-obtained HPCs show favorable features for electrochemical energy storage such as high specific surface area of up to 2085 m2 g-1, high volume of pores up to 1.89 cm3 g-1, hierarchical porosity consisting of micro, meso, and macropores, turbostratic carbon structure, uniform pore size and rich oxygen-doping (21.20%). The supercapacitor performance of HPCs exhibit a high specific capacitance 314 F g-1 at a current density of 0.5 A g-1 and 237 F g-1 at a current density of 20 A g-1, ultra-high rate capability with 83% retention rate from 1 to 20 A g-1 and outstanding cycling stability with 96% capacitance retention after 2000 cycles. The facile, efficient and green synthesis strategy for novel HPCs from polymer sources could find use in supercapacitors, lithium ion batteries, fuel cells and sorbents.

  11. Hierarchical Affinity Propagation

    CERN Document Server

    Givoni, Inmar; Frey, Brendan J

    2012-01-01

    Affinity propagation is an exemplar-based clustering algorithm that finds a set of data-points that best exemplify the data, and associates each datapoint with one exemplar. We extend affinity propagation in a principled way to solve the hierarchical clustering problem, which arises in a variety of domains including biology, sensor networks and decision making in operational research. We derive an inference algorithm that operates by propagating information up and down the hierarchy, and is efficient despite the high-order potentials required for the graphical model formulation. We demonstrate that our method outperforms greedy techniques that cluster one layer at a time. We show that on an artificial dataset designed to mimic the HIV-strain mutation dynamics, our method outperforms related methods. For real HIV sequences, where the ground truth is not available, we show our method achieves better results, in terms of the underlying objective function, and show the results correspond meaningfully to geographi...

  12. Associative Hierarchical Random Fields.

    Science.gov (United States)

    Ladický, L'ubor; Russell, Chris; Kohli, Pushmeet; Torr, Philip H S

    2014-06-01

    This paper makes two contributions: the first is the proposal of a new model-The associative hierarchical random field (AHRF), and a novel algorithm for its optimization; the second is the application of this model to the problem of semantic segmentation. Most methods for semantic segmentation are formulated as a labeling problem for variables that might correspond to either pixels or segments such as super-pixels. It is well known that the generation of super pixel segmentations is not unique. This has motivated many researchers to use multiple super pixel segmentations for problems such as semantic segmentation or single view reconstruction. These super-pixels have not yet been combined in a principled manner, this is a difficult problem, as they may overlap, or be nested in such a way that the segmentations form a segmentation tree. Our new hierarchical random field model allows information from all of the multiple segmentations to contribute to a global energy. MAP inference in this model can be performed efficiently using powerful graph cut based move making algorithms. Our framework generalizes much of the previous work based on pixels or segments, and the resulting labelings can be viewed both as a detailed segmentation at the pixel level, or at the other extreme, as a segment selector that pieces together a solution like a jigsaw, selecting the best segments from different segmentations as pieces. We evaluate its performance on some of the most challenging data sets for object class segmentation, and show that this ability to perform inference using multiple overlapping segmentations leads to state-of-the-art results. PMID:26353271

  13. Micromechanics of hierarchical materials

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon, Jr.

    2012-01-01

    nanoengineered matrix, fiber bundle model of UD composites with hierarchically clustered fibers and 3D multilevel model of wood considered as a gradient, cellular material with layered composite cell walls. The main areas of research in micromechanics of hierarchical materials are identified, among them, the...

  14. Hierarchical Models of Attitude.

    Science.gov (United States)

    Reddy, Srinivas K.; LaBarbera, Priscilla A.

    1985-01-01

    The application and use of hierarchical models is illustrated, using the example of the structure of attitudes toward a new product and a print advertisement. Subjects were college students who responded to seven-point bipolar scales. Hierarchical models were better than nonhierarchical models in conceptualizing attitude but not intention. (GDC)

  15. A biologically-inspired framework for contour detection using superpixel-based candidates and hierarchical visual cues.

    Science.gov (United States)

    Sun, Xiao; Shang, Ke; Ming, Delie; Tian, Jinwen; Ma, Jiayi

    2015-01-01

    Contour detection has been extensively investigated as a fundamental problem in computer vision. In this study, a biologically-inspired candidate weighting framework is proposed for the challenging task of detecting meaningful contours. In contrast to previous models that detect contours from pixels, a modified superpixel generation processing is proposed to generate a contour candidate set and then weigh the candidates by extracting hierarchical visual cues. We extract the low-level visual local cues to weigh the contour intrinsic property and mid-level visual cues on the basis of Gestalt principles for weighting the contour grouping constraint. Experimental results tested on the BSDS benchmark show that the proposed framework exhibits promising performances to capture meaningful contours in complex scenes. PMID:26492252

  16. The multivariate Wright-Fisher process with mutation: Moment-based analysis and inference using a hierarchical Beta model.

    Science.gov (United States)

    Hobolth, Asger; Siren, Jukka

    2016-04-01

    We consider the diffusion approximation of the multivariate Wright-Fisher process with mutation. Analytically tractable formulas for the first-and second-order moments of the allele frequency distribution are derived, and the moments are subsequently used to better understand key population genetics parameters and modeling frameworks. In particular we investigate the behavior of the expected homozygosity (the probability that two randomly sampled genes are identical) in the transient and stationary phases, and how appropriate the Dirichlet distribution is for modeling the allele frequency distribution at different evolutionary time scales. We find that the Dirichlet distribution is adequate for the pure drift model (no mutations allowed), but the distribution is not sufficiently flexible for more general mutation models. We suggest a new hierarchical Beta distribution for the allele frequencies in the Wright-Fisher process with a mutation model on the nucleotide level that distinguishes between transitions and transversions. PMID:26612605

  17. Hierarchical quantum communication

    International Nuclear Information System (INIS)

    A general approach to study the hierarchical quantum information splitting (HQIS) is proposed and the same is used to systematically investigate the possibility of realizing HQIS using different classes of 4-qubit entangled states that are not connected by stochastic local operations and classical communication (SLOCC). Explicit examples of HQIS using 4-qubit cluster state and 4-qubit |Ω〉 state are provided. Further, the proposed HQIS scheme is generalized to introduce two new aspects of hierarchical quantum communication. To be precise, schemes of probabilistic hierarchical quantum information splitting and hierarchical quantum secret sharing are obtained by modifying the proposed HQIS scheme. A number of practical situations where hierarchical quantum communication would be of use, are also presented.

  18. Hierarchical energy management system for stand-alone hybrid system based on generation costs and cascade control

    International Nuclear Information System (INIS)

    Highlights: • We present an energy management system for a stand-alone WT/PV/hydrogen/battery hybrid system. • Hierarchical control composed by master and slave control strategies. • Control assures reliable electricity support for stand-alone applications subject to technical and economic criteria. - Abstract: This paper presents an energy management system (EMS) for stand-alone hybrid systems composed by photovoltaic (PV) solar panels and a wind turbine (WT) as primary energy sources and two energy storage systems, which are a hydrogen system and a battery. The hydrogen system is composed of fuel cell (FC), electrolyzer and hydrogen storage tank. The EMS is a hierarchical control composed by a master control strategy and a slave control strategy. On the one hand, the master control generates the reference powers to meet several premises (such as to satisfy the load power demand, and to maintain the hydrogen tank level and the state of charge (SOC) of the battery between their target margins), taking also into account economic aspects to discriminate between using the battery or hydrogen system. On the other hand, the slave control modifies the reference powers generated by the master control according to the energy sources dynamic limitations, and maintains the DC bus voltage at its reference value. The models, implemented in MATLAB-Simulink environment, have been developed from commercially available components. To check the viability of the proposed EMS, two kinds of simulations were carried out: (1) A long-term simulation of 25 years (expected lifetime of the system) with a sample time of one hour to validate the master control of the EMS; and (2) A short-term simulation with sudden net power variations to validate the slave control of the EMS

  19. Hierarchical fringe tracking

    CERN Document Server

    Petrov, Romain G; Boskri, Abdelkarim; Folcher, Jean-Pierre; Lagarde, Stephane; Bresson, Yves; Benkhaldoum, Zouhair; Lazrek, Mohamed; Rakshit, Suvendu

    2014-01-01

    The limiting magnitude is a key issue for optical interferometry. Pairwise fringe trackers based on the integrated optics concepts used for example in GRAVITY seem limited to about K=10.5 with the 8m Unit Telescopes of the VLTI, and there is a general "common sense" statement that the efficiency of fringe tracking, and hence the sensitivity of optical interferometry, must decrease as the number of apertures increases, at least in the near infrared where we are still limited by detector readout noise. Here we present a Hierarchical Fringe Tracking (HFT) concept with sensitivity at least equal to this of a two apertures fringe trackers. HFT is based of the combination of the apertures in pairs, then in pairs of pairs then in pairs of groups. The key HFT module is a device that behaves like a spatial filter for two telescopes (2TSF) and transmits all or most of the flux of a cophased pair in a single mode beam. We give an example of such an achromatic 2TSF, based on very broadband dispersed fringes analyzed by g...

  20. Gene-Set Local Hierarchical Clustering (GSLHC--A Gene Set-Based Approach for Characterizing Bioactive Compounds in Terms of Biological Functional Groups.

    Directory of Open Access Journals (Sweden)

    Feng-Hsiang Chung

    Full Text Available Gene-set-based analysis (GSA, which uses the relative importance of functional gene-sets, or molecular signatures, as units for analysis of genome-wide gene expression data, has exhibited major advantages with respect to greater accuracy, robustness, and biological relevance, over individual gene analysis (IGA, which uses log-ratios of individual genes for analysis. Yet IGA remains the dominant mode of analysis of gene expression data. The Connectivity Map (CMap, an extensive database on genomic profiles of effects of drugs and small molecules and widely used for studies related to repurposed drug discovery, has been mostly employed in IGA mode. Here, we constructed a GSA-based version of CMap, Gene-Set Connectivity Map (GSCMap, in which all the genomic profiles in CMap are converted, using gene-sets from the Molecular Signatures Database, to functional profiles. We showed that GSCMap essentially eliminated cell-type dependence, a weakness of CMap in IGA mode, and yielded significantly better performance on sample clustering and drug-target association. As a first application of GSCMap we constructed the platform Gene-Set Local Hierarchical Clustering (GSLHC for discovering insights on coordinated actions of biological functions and facilitating classification of heterogeneous subtypes on drug-driven responses. GSLHC was shown to tightly clustered drugs of known similar properties. We used GSLHC to identify the therapeutic properties and putative targets of 18 compounds of previously unknown characteristics listed in CMap, eight of which suggest anti-cancer activities. The GSLHC website http://cloudr.ncu.edu.tw/gslhc/ contains 1,857 local hierarchical clusters accessible by querying 555 of the 1,309 drugs and small molecules listed in CMap. We expect GSCMap and GSLHC to be widely useful in providing new insights in the biological effect of bioactive compounds, in drug repurposing, and in function-based classification of complex diseases.

  1. Gene-Set Local Hierarchical Clustering (GSLHC)--A Gene Set-Based Approach for Characterizing Bioactive Compounds in Terms of Biological Functional Groups.

    Science.gov (United States)

    Chung, Feng-Hsiang; Jin, Zhen-Hua; Hsu, Tzu-Ting; Hsu, Chueh-Lin; Liu, Hsueh-Chuan; Lee, Hoong-Chien

    2015-01-01

    Gene-set-based analysis (GSA), which uses the relative importance of functional gene-sets, or molecular signatures, as units for analysis of genome-wide gene expression data, has exhibited major advantages with respect to greater accuracy, robustness, and biological relevance, over individual gene analysis (IGA), which uses log-ratios of individual genes for analysis. Yet IGA remains the dominant mode of analysis of gene expression data. The Connectivity Map (CMap), an extensive database on genomic profiles of effects of drugs and small molecules and widely used for studies related to repurposed drug discovery, has been mostly employed in IGA mode. Here, we constructed a GSA-based version of CMap, Gene-Set Connectivity Map (GSCMap), in which all the genomic profiles in CMap are converted, using gene-sets from the Molecular Signatures Database, to functional profiles. We showed that GSCMap essentially eliminated cell-type dependence, a weakness of CMap in IGA mode, and yielded significantly better performance on sample clustering and drug-target association. As a first application of GSCMap we constructed the platform Gene-Set Local Hierarchical Clustering (GSLHC) for discovering insights on coordinated actions of biological functions and facilitating classification of heterogeneous subtypes on drug-driven responses. GSLHC was shown to tightly clustered drugs of known similar properties. We used GSLHC to identify the therapeutic properties and putative targets of 18 compounds of previously unknown characteristics listed in CMap, eight of which suggest anti-cancer activities. The GSLHC website http://cloudr.ncu.edu.tw/gslhc/ contains 1,857 local hierarchical clusters accessible by querying 555 of the 1,309 drugs and small molecules listed in CMap. We expect GSCMap and GSLHC to be widely useful in providing new insights in the biological effect of bioactive compounds, in drug repurposing, and in function-based classification of complex diseases. PMID:26473729

  2. Fluorinated Polyhedral Oligomeric Silsesquioxane Based Giant Molecular Shape Amphiphiles: Hierarchical Self-Assembly with Unusual Chain Conformation

    Science.gov (United States)

    Dong, Xue-Hui; Bo NI Collaboration; Ziran Chen Collaboration; Yiwen Li Collaboration; Wen-Bin Zhang Collaboration; Stephen Z. D. Cheng Collaboration

    2014-03-01

    The fluorous phase has thus been considered as the third phase that repels both oil and water due to its ultra-low surface energy. Incorporation of fluorinated component into hydrophilic/hydrophobic polymers is anticipated to bring novel self-assembly behaviors in the bulk, solution and thin film states, which are not only academically intriguing but also technological relevant. Among them, fluorous molecular clusters are of particular interest. A topologic isomer pair of giant molecular shape amphiphiles can be constructed by tethering molecular nanoparticle at different location of block polymers. In this study, a fluorinated polyhedral oligomeric silsesquioxane (FPOSS) was precisely fixed onto polystyreneblockpoly(ethylene oxide) (PS- b-PEO) at chain end (FPOSS-PS- b-PEO), or junction point [PS-(FPOSS)-PEO]. The interplay between nanoparticle and block polymers results in hierarchical structures with three types of order. The incommensuration of cross-sectional area between FPOSS and block polymer stretches polymer chains, which found to enhance the immiscibility between PEO and PS block.

  3. Micro- and nanophase separations in hierarchical self-assembly of strongly amphiphilic block copolymer-based ionic supramolecules

    DEFF Research Database (Denmark)

    Ayoubi, Mehran Asad; Zhu, Kaizheng; Nyström, Bo;

    2013-01-01

    the samples. The morphology of the microphase separated state was mapped out on 'master' microdomain morphology diagrams as a function of the volume fraction of the AmphComb blocks (Φ AmphComb) and the compositional window of each microdomain morphology was determined. It was observed that, (i) within...... block), a class of ionic supramolecules are successfully synthesized whose molecular architecture consists of a poly(styrene) PS block (Linear block) covalently connected to a strongly amphiphilic comb-like block (AmphComb block), i.e. Linear-b-AmphComb. In the melt state, these ionic supramolecules can...... show simultaneous microphase (between Linear and AmphComb blocks) and nanophase (within the AmphComb blocks) separations. This leads to the formation of various structure-in-structure two-scale hierarchical self-assemblies, including S-in-SLL, S-in-SBCC, S-in-C, S-in-L and C-in-L, where S, SLL, SBCC, C...

  4. Hierarchic Models of Turbulence, Superfluidity and Superconductivity

    OpenAIRE

    Kaivarainen, Alex

    2000-01-01

    New models of Turbulence, Superfluidity and Superconductivity, based on new Hierarchic theory, general for liquids and solids (physics/0102086), have been proposed. CONTENTS: 1 Turbulence. General description; 2 Mesoscopic mechanism of turbulence; 3 Superfluidity. General description; 4 Mesoscopic scenario of fluidity; 5 Superfluidity as a hierarchic self-organization process; 6 Superfluidity in 3He; 7 Superconductivity: General properties of metals and semiconductors; Plasma oscillations; Cy...

  5. Learning Word Representations with Hierarchical Sparse Coding

    OpenAIRE

    Yogatama, Dani; Faruqui, Manaal; Dyer, Chris; Smith, Noah A.

    2014-01-01

    We propose a new method for learning word representations using hierarchical regularization in sparse coding inspired by the linguistic study of word meanings. We show an efficient learning algorithm based on stochastic proximal methods that is significantly faster than previous approaches, making it possible to perform hierarchical sparse coding on a corpus of billions of word tokens. Experiments on various benchmark tasks---word similarity ranking, analogies, sentence completion, and sentim...

  6. Aspects Of Multicriterial Mathematical Modeling And Of The Fuzzy Formalism For The Hierarchization Of Study Programs Based On Several Quality Characteristics

    Science.gov (United States)

    Bucur, Amelia

    2015-09-01

    The aim of this paper is to present aspects of mathematical modeling for the hierarchization of study programs from universities, based on several quality characteristics. The tools used pertain to multicriterial optimization, to the different methods of assessing importance coefficients, to the utility theory, the fuzzy formalism, and to the fuzzy simple additive weighting method. The conclusion is that multicriterial decision-making methods can be efficiently used in assessing the quality of study programs, noting that, just like other methods from the decision theory, the multicriterial decision-making methods highlight aspects of problems differently, therefore, there can be no comparison or competitiveness between them, and choosing one over the other is up to the decision-maker.

  7. Hierarchical Self-Assembly of Polyoxometalate-Based Hybrids Driven by Metal Coordination and Electrostatic Interactions: From Discrete Supramolecular Species to Dense Monodisperse Nanoparticles.

    Science.gov (United States)

    Izzet, Guillaume; Abécassis, Benjamin; Brouri, Dalil; Piot, Madeleine; Matt, Benjamin; Serapian, Stefano Artin; Bo, Carles; Proust, Anna

    2016-04-20

    The metal-driven self-assembly processes of a covalent polyoxometalate (POM)-based hybrid bearing remote terpyridine binding sites have been investigated. In a strongly dissociating solvent, a discrete metallomacrocycle, described as a molecular triangle, is formed and characterized by 2D diffusion NMR spectroscopy (DOSY), small-angle X-ray scattering (SAXS), and molecular modeling. In a less dissociating solvent, the primary supramolecular structure, combining negatively charged POMs and cationic metal linkers, further self-assemble through intermolecular electrostatic interactions in a reversible process. The resulting hierarchical assemblies are dense monodisperse nanoparticles composed of ca. 50 POMs that were characterized by SAXS and transmission electron microscopy (TEM). This multiscale organized system directed by metal coordination and electrostatic interactions constitutes a promising step for the future design of POM self-assemblies with controllable structure-directing factors. PMID:27019075

  8. Micromechanics of hierarchical materials

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon, Jr.

    2012-01-01

    A short overview of micromechanical models of hierarchical materials (hybrid composites, biomaterials, fractal materials, etc.) is given. Several examples of the modeling of strength and damage in hierarchical materials are summarized, among them, 3D FE model of hybrid composites with...... nanoengineered matrix, fiber bundle model of UD composites with hierarchically clustered fibers and 3D multilevel model of wood considered as a gradient, cellular material with layered composite cell walls. The main areas of research in micromechanics of hierarchical materials are identified, among them, the...... investigations of the effects of load redistribution between reinforcing elements at different scale levels, of the possibilities to control different material properties and to ensure synergy of strengthening effects at different scale levels and using the nanoreinforcement effects. The main future directions...

  9. Programming with Hierarchical Maps

    DEFF Research Database (Denmark)

    Ørbæk, Peter

    This report desribes the hierarchical maps used as a central data structure in the Corundum framework. We describe its most prominent features, ague for its usefulness and briefly describe some of the software prototypes implemented using the technology....

  10. Hierarchical Network Design

    DEFF Research Database (Denmark)

    Thomadsen, Tommy

    2005-01-01

    Communication networks are immensely important today, since both companies and individuals use numerous services that rely on them. This thesis considers the design of hierarchical (communication) networks. Hierarchical networks consist of layers of networks and are well-suited for coping...... with changing and increasing demands. Two-layer networks consist of one backbone network, which interconnects cluster networks. The clusters consist of nodes and links, which connect the nodes. One node in each cluster is a hub node, and the backbone interconnects the hub nodes of each cluster and thus...... the clusters. The design of hierarchical networks involves clustering of nodes, hub selection, and network design, i.e. selection of links and routing of ows. Hierarchical networks have been in use for decades, but integrated design of these networks has only been considered for very special types of networks...

  11. Hierarchical Semantic Model of Geovideo

    Directory of Open Access Journals (Sweden)

    XIE Xiao

    2015-05-01

    Full Text Available The public security incidents were getting increasingly challenging with regard to their new features, including multi-scale mobility, multistage dynamic evolution, as well as spatiotemporal concurrency and uncertainty in the complex urban environment. However, the existing video models, which were used/designed for independent archive or local analysis of surveillance video, have seriously inhibited emergency response to the urgent requirements.Aiming at the explicit representation of change mechanism in video, the paper proposed a novel hierarchical geovideo semantic model using UML. This model was characterized by the hierarchical representation of both data structure and semantics based on the change-oriented three domains (feature domain, process domain and event domain instead of overall semantic description of video streaming; combining both geographical semantics and video content semantics, in support of global semantic association between multiple geovideo data. The public security incidents by video surveillance are inspected as an example to illustrate the validity of this model.

  12. Automatic Hierarchical Color Image Classification

    Directory of Open Access Journals (Sweden)

    Jing Huang

    2003-02-01

    Full Text Available Organizing images into semantic categories can be extremely useful for content-based image retrieval and image annotation. Grouping images into semantic classes is a difficult problem, however. Image classification attempts to solve this hard problem by using low-level image features. In this paper, we propose a method for hierarchical classification of images via supervised learning. This scheme relies on using a good low-level feature and subsequently performing feature-space reconfiguration using singular value decomposition to reduce noise and dimensionality. We use the training data to obtain a hierarchical classification tree that can be used to categorize new images. Our experimental results suggest that this scheme not only performs better than standard nearest-neighbor techniques, but also has both storage and computational advantages.

  13. Top-Down Feedback in an HMAX-Like Cortical Model of Object Perception Based on Hierarchical Bayesian Networks and Belief Propagation

    OpenAIRE

    Salvador Dura-Bernal; Thomas Wennekers; DENHAM, SUSAN L.

    2012-01-01

    Hierarchical generative models, such as Bayesian networks, and belief propagation have been shown to provide a theoretical framework that can account for perceptual processes, including feedforward recognition and feedback modulation. The framework explains both psychophysical and physiological experimental data and maps well onto the hierarchical distributed cortical anatomy. However, the complexity required to model cortical processes makes inference, even using approximate methods, very co...

  14. Photovoltaic and Impedance Properties of Hierarchical TiO2 Nanowire Based Quantum Dot Sensitized Solar Cell

    Directory of Open Access Journals (Sweden)

    Amanullah Fatehmulla

    2015-01-01

    Full Text Available Growth and characterization of TiO2 nanowire (NW assemblies on FTO glass using a typical hydrothermal synthesis have been reported. CdS quantum dots (QDs have been deposited on TiO2 nanowires by successive ion layer adsorption and reaction (SILAR method. FESEM image exhibits the flower-like hierarchical TiO2 bunch of nanowires. HRTEM image confirms the size of CdS QDs between 5 and 6 nm. XRD and absorption studies revealed proper growth of CdS quantum dots on TiO2 nanowires. At AM 1.5 illumination intensity, the solar cell, with the configuration FTO/TiO2-NW/CdS-QDs/Pt-FTO, displays a short circuit current (Jsc of 1.295 mA and an open circuit voltage (Voc of 0.38 V. The Voc and Jsc showed linear behavior at higher illumination intensities. The peak in power-voltage characteristics at various illuminations showed a shift towards higher Voc values. Capacitance-voltage (C-V, conductance-voltage (G-V, and series resistance-voltage (Rs-V measurements of the cell in the frequency ranging from 5 kHz to 5 MHz showed decreasing trend of capacitance with increase of frequency whereas increase in conductance and decrease in resistance have been noticed with increase of frequency. All the results including the individual behavior of the plots of capacitance, conductance, and series resistance as a function of bias voltage have been discussed.

  15. Generation of hierarchically correlated multivariate symbolic sequences

    CERN Document Server

    Tumminello, Mi; Mantegna, R N

    2008-01-01

    We introduce an algorithm to generate multivariate series of symbols from a finite alphabet with a given hierarchical structure of similarities. The target hierarchical structure of similarities is arbitrary, for instance the one obtained by some hierarchical clustering procedure as applied to an empirical matrix of Hamming distances. The algorithm can be interpreted as the finite alphabet equivalent of the recently introduced hierarchically nested factor model (M. Tumminello et al. EPL 78 (3) 30006 (2007)). The algorithm is based on a generating mechanism that is different from the one used in the mutation rate approach. We apply the proposed methodology for investigating the relationship between the bootstrap value associated with a node of a phylogeny and the probability of finding that node in the true phylogeny.

  16. Hierarchical multifunctional nanocomposites

    Science.gov (United States)

    Ghasemi-Nejhad, Mehrdad N.

    2014-03-01

    Nanocomposites; including nano-materials such as nano-particles, nanoclays, nanofibers, nanotubes, and nanosheets; are of significant importance in the rapidly developing field of nanotechnology. Due to the nanometer size of these inclusions, their physicochemical characteristics differ significantly from those of micron size and bulk materials. The field of nanocomposites involves the study of multiphase materials where at least one of the constituent phases has one dimension less than 100 nm. This is the range where the phenomena associated with the atomic and molecular interaction strongly influence the macroscopic properties of materials. Since the building blocks of nanocomposites are at nanoscale, they have an enormous surface area with numerous interfaces between the two intermix phases. The special properties of the nano-composite arise from the interaction of its phases at the interface and/or interphase regions. By contrast, in a conventional composite based on micrometer sized filler such as carbon fibers, the interfaces between the filler and matrix constitutes have a much smaller surface-to-volume fraction of the bulk materials, and hence influence the properties of the host structure to a much smaller extent. The optimum amount of nanomaterials in the nanocomposites depends on the filler size, shape, homogeneity of particles distribution, and the interfacial bonding properties between the fillers and matrix. The promise of nanocomposites lies in their multifunctionality, i.e., the possibility of realizing unique combination of properties unachievable with traditional materials. The challenges in reaching this promise are tremendous. They include control over the distribution in size and dispersion of the nanosize constituents, and tailoring and understanding the role of interfaces between structurally or chemically dissimilar phases on bulk properties. While the properties of the matrix can be improved by the inclusions of nanomaterials, the

  17. Hierarchical fringe tracking

    Science.gov (United States)

    Petrov, Romain G.; Elhalkouj, Thami; Boskri, Abdelkarim; Folcher, Jean-Pierre; Lagarde, Stéphane; Bresson, Yves; Benkhaldoun, Zouhair; Lazrek, Mohamed; Rakshit, Suvendu

    2014-07-01

    The limiting magnitude is a key issue for optical interferometry. Pairwise fringe trackers based on the integrated optics concepts used for example in GRAVITY seem limited to about K=10.5 with the 8m Unit Telescopes of the VLTI, and there is a general "common sense" statement that the efficiency of fringe tracking, and hence the sensitivity of optical interferometry, must decrease as the number of apertures increases, at least in the near infrared where we are still limited by detector readout noise. Here we present a Hierarchical Fringe Tracking (HFT) concept with sensitivity at least equal to this of a two apertures fringe trackers. HFT is based of the combination of the apertures in pairs, then in pairs of pairs then in pairs of groups… The key HFT module is a device that behaves like a spatial filter for two telescopes (2TSF) and transmits all or most of the flux of a cophased pair in a single mode beam. We give an example of such an achromatic 2TSF, based on very broadband dispersed fringes analyzed by grids, and show that it allows piston measures from very broadband fringes with only 3 to 5 pixels per fringe tracker. We show the results of numerical simulation indicating that our device is a good achromatic spatial filter and allowing a first evaluation of its coupling efficiency, which is similar to this of a single mode fiber on a single aperture. Our very preliminary results indicate that HFT has a good chance to be a serious candidate for the most sensitive fringe tracking with the VLTI and also interferometers with much larger number of apertures. On the VLTI the first rough estimate of the magnitude gain with regard to the GRAVITY internal FT is between 2.5 and 3.5 magnitudes in K, with a decisive impact on the VLTI science program for AGNs, Young stars and planet forming disks.

  18. Parallel hierarchical radiosity rendering

    Energy Technology Data Exchange (ETDEWEB)

    Carter, M.

    1993-07-01

    In this dissertation, the step-by-step development of a scalable parallel hierarchical radiosity renderer is documented. First, a new look is taken at the traditional radiosity equation, and a new form is presented in which the matrix of linear system coefficients is transformed into a symmetric matrix, thereby simplifying the problem and enabling a new solution technique to be applied. Next, the state-of-the-art hierarchical radiosity methods are examined for their suitability to parallel implementation, and scalability. Significant enhancements are also discovered which both improve their theoretical foundations and improve the images they generate. The resultant hierarchical radiosity algorithm is then examined for sources of parallelism, and for an architectural mapping. Several architectural mappings are discussed. A few key algorithmic changes are suggested during the process of making the algorithm parallel. Next, the performance, efficiency, and scalability of the algorithm are analyzed. The dissertation closes with a discussion of several ideas which have the potential to further enhance the hierarchical radiosity method, or provide an entirely new forum for the application of hierarchical methods.

  19. Hierarchical Coding Vectors for Scene Level Land-Use Classification

    OpenAIRE

    Hang Wu; Baozhen Liu; Weihua Su; Wenchang Zhang; Jinggong Sun

    2016-01-01

    Land-use classification from remote sensing images has become an important but challenging task. This paper proposes Hierarchical Coding Vectors (HCV), a novel representation based on hierarchically coding structures, for scene level land-use classification. We stack multiple Bag of Visual Words (BOVW) coding layers and one Fisher coding layer to develop the hierarchical feature learning structure. In BOVW coding layers, we extract local descriptors from a geographical image with densely samp...

  20. Chimera states in hierarchical networks of Van der Pol oscillators

    OpenAIRE

    Ulonska, Stefan; Omelchenko, Iryna; Zakharova, Anna; Schoell, Eckehard

    2016-01-01

    Chimera states are complex spatio-temporal patterns that consist of coexisting domains of coherent and incoherent dynamics. We analyse chimera states in networks of Van der Pol oscillators with hierarchical coupling topology. We investigate the stepwise transition from a nonlocal to a hierarchical topology, and propose the network clustering coefficient as a measure to establish a link between the existence of chimera states and the compactness of the initial base pattern of a hierarchical to...

  1. Hierarchical object-based mapping of riverscape units and in-stream mesohabitats using LiDAR and VHR imagery

    OpenAIRE

    Luca Demarchi; Simone Bizzi; Hervé Piégay

    2015-01-01

    In this paper, we present a new, semi-automated methodology for mapping hydromorphological indicators of rivers at a regional scale using multisource remote sensing (RS) data. This novel approach is based on the integration of spectral and topographic information within a multilevel, geographic, object-based image analysis (GEOBIA). Different segmentation levels were generated based on the two sources of Remote Sensing (RS) data, namely very-high spatial resolution, near-infrared imagery (VHR...

  2. Hierarchical Neural Network Structures for Phoneme Recognition

    CERN Document Server

    Vasquez, Daniel; Minker, Wolfgang

    2013-01-01

    In this book, hierarchical structures based on neural networks are investigated for automatic speech recognition. These structures are evaluated on the phoneme recognition task where a  Hybrid Hidden Markov Model/Artificial Neural Network paradigm is used. The baseline hierarchical scheme consists of two levels each which is based on a Multilayered Perceptron. Additionally, the output of the first level serves as a second level input. The computational speed of the phoneme recognizer can be substantially increased by removing redundant information still contained at the first level output. Several techniques based on temporal and phonetic criteria have been investigated to remove this redundant information. The computational time could be reduced by 57% whilst keeping the system accuracy comparable to the baseline hierarchical approach.

  3. Catalysis with hierarchical zeolites

    DEFF Research Database (Denmark)

    Holm, Martin Spangsberg; Taarning, Esben; Egeblad, Kresten;

    2011-01-01

    Hierarchical (or mesoporous) zeolites have attracted significant attention during the first decade of the 21st century, and so far this interest continues to increase. There have already been several reviews giving detailed accounts of the developments emphasizing different aspects of this resear...

  4. Hierarchical Porous Structures

    Energy Technology Data Exchange (ETDEWEB)

    Grote, Christopher John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-07

    Materials Design is often at the forefront of technological innovation. While there has always been a push to generate increasingly low density materials, such as aero or hydrogels, more recently the idea of bicontinuous structures has gone more into play. This review will cover some of the methods and applications for generating both porous, and hierarchically porous structures.

  5. Tight bifunctional hierarchical catalyst.

    Science.gov (United States)

    Højholt, Karen T; Vennestrøm, Peter N R; Tiruvalam, Ramchandra; Beato, Pablo

    2011-12-28

    A new concept to prepare tight bifunctional catalysts has been developed, by anchoring CoMo(6) clusters on hierarchical ZSM-5 zeolites for simultaneous use in HDS and hydrocracking catalysis. The prepared material displays a significant improved activity in HDS catalysis compared to the impregnated counterpart. PMID:22048337

  6. Hierarchically Acting Sterile Neutrinos

    OpenAIRE

    Chen, Chian-Shu(Physics Division, National Center for Theoretical Sciences, Hsinchu, 300, Taiwan); Takahashi, Ryo

    2011-01-01

    We propose that a hierarchical spectrum of sterile neutrinos (eV, keV, $10^{13-15}$ GeV) is considered to as the explanations for MiniBooNE and LSND oscillation anomalies, dark matter, and baryon asymmetry of the universe (BAU) respectively. The scenario can also realize the smallness of active neutrino masses by seesaw mechanism.

  7. 基于潜在Dirichlet分布的图像分层表示模型%Image Hierarchical Representation Model Based on LDA

    Institute of Scientific and Technical Information of China (English)

    贾振华; 斯庆巴拉

    2013-01-01

    The existing image hierarchical representation methods are strict in feed-forward style, and therefore it is not able to solve problems like local ambiguities well. In this paper, a probabilistic model is proposed to learn and deduce all layers of the hierarchy together. Specifically, a recursive probabilistic decomposition process is taken into account, and a generative model based on latent Dirichlet allocation with pyramidal multilayer structure is derived. Two important properties of the proposed probabilistic model are demonstrated:adding an additional representation layer to improve the performance of the flat model and adopting a full Bayesian approach which is better than a feed-forward implementation of the model. Experimental results on a standard recognition dataset show that the proposed method outperforms the existing hierarchical approaches, and it improves the classification and the learning accuracy with better performance.%现有的图像分层表示方法严格局限于前馈型方式,不能较好地解决局部模糊性等问题。基于此,文中提出一种学习和推断层次结构所有分层的概率模型,它考虑递归的概率分解过程,通过推导得到金字塔式多层结构的潜在Dirichlet分布的衍生模型。该模型存在两个重要特性:增加表示层可提高平面模型的性能;采用全Bayesian概率方法优于其前馈型实现形式。在标准识别数据集上的实验结果表明,与现有的分层表示方法相比,该模型表现出较好性能。

  8. Hierarchical Cluster-based Partial Least Squares Regression (HC-PLSR is an efficient tool for metamodelling of nonlinear dynamic models

    Directory of Open Access Journals (Sweden)

    Omholt Stig W

    2011-06-01

    Full Text Available Abstract Background Deterministic dynamic models of complex biological systems contain a large number of parameters and state variables, related through nonlinear differential equations with various types of feedback. A metamodel of such a dynamic model is a statistical approximation model that maps variation in parameters and initial conditions (inputs to variation in features of the trajectories of the state variables (outputs throughout the entire biologically relevant input space. A sufficiently accurate mapping can be exploited both instrumentally and epistemically. Multivariate regression methodology is a commonly used approach for emulating dynamic models. However, when the input-output relations are highly nonlinear or non-monotone, a standard linear regression approach is prone to give suboptimal results. We therefore hypothesised that a more accurate mapping can be obtained by locally linear or locally polynomial regression. We present here a new method for local regression modelling, Hierarchical Cluster-based PLS regression (HC-PLSR, where fuzzy C-means clustering is used to separate the data set into parts according to the structure of the response surface. We compare the metamodelling performance of HC-PLSR with polynomial partial least squares regression (PLSR and ordinary least squares (OLS regression on various systems: six different gene regulatory network models with various types of feedback, a deterministic mathematical model of the mammalian circadian clock and a model of the mouse ventricular myocyte function. Results Our results indicate that multivariate regression is well suited for emulating dynamic models in systems biology. The hierarchical approach turned out to be superior to both polynomial PLSR and OLS regression in all three test cases. The advantage, in terms of explained variance and prediction accuracy, was largest in systems with highly nonlinear functional relationships and in systems with positive feedback

  9. HIERARCHICAL COLORED PETRI NET BASED REQUIREMENT ENGINEERING PROCESS FRAMEWORK%基于层次着色Petri网的需求工程过程框架

    Institute of Scientific and Technical Information of China (English)

    张国生

    2011-01-01

    A hierarchical colored Petri net based requirement engineering process framework is put forward, which formally defines the engineering processes, requirement activities, requirement tasks and functions of software requirements, implements a clear, full, unambiguous and precise framework description for software requirement engineering, establishes a solid foundation for creating high quality software requirement specifications in the end, and additionally provides strict mathematical guidance for software requirement refinement, specification, reuse and evolution as well as requirement management, requirement quality control, measurement and so on.%提出一种基于层次着色Petri网的需求工程过程框架,对软件需求工程过程、需求活动、需求任务及其功能进行了形式化定义,为软件需求工程实现了一个清晰、完整、无二义性的精确描述框架,并为最终产生高质量的软件需求规格说明奠定了坚实的基础,也为软件需求的精化、规约、复用、演化以及需求管理、需求质量控制、度量等提供了严格数学依据.

  10. A highly sensitive and stable electrochemical sensor for simultaneous detection towards ascorbic acid, dopamine, and uric acid based on the hierarchical nanoporous PtTi alloy.

    Science.gov (United States)

    Zhao, Dianyun; Yu, Guolong; Tian, Kunlong; Xu, Caixia

    2016-08-15

    In current work highly sensitive and stable electrochemical sensor for simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) is constructed based on the hierarchical nanoporous (HNP) PtTi alloy. The HNP-PtTi alloy is simply fabricated by two-step dealloying process, characterized by the bimodal ligament/pore size distributions and interconnected hollow channels. The HNP structure with the advantages of large surface area, excellent structure stability, and rich pore channels is used for facilitating the electron conductivity and the mass transfer. Combined with the dual effects of the bimodal nanoporous architecture and the excellent electrocatalytic activity of PtTi alloy, the constructed sensor exhibits high electrochemical sensing activity with wide linear responses from 0.2 to 1mM, 0.004 to 0.5mM, and 0.1 to 1mM for simultaneous detection of AA, DA, and UA, respectively. In addition, HNP-PtTi alloy also shows long-term sensing stability towards the AA, DA, and UA detection and behaves as a good anti-interference towards NaCl, KCl, FeCl3, CuCl2, AlCl3, glucose, and H2O2. The HNP-PtTi alloy manifests intriguing application potential as the candidate for the application of the electrochemical sensor for simultaneous detection of AA, DA, and UA. PMID:27058442

  11. Collective fabrication of all-organic microcantilever chips based on a hierarchical combination of shadow-masking and wafer-bonding processing methods

    International Nuclear Information System (INIS)

    This paper describes a new collective microfabrication process of all-organic microcantilever chips. This method is based on the hierarchical combination of shadow-masking and wafer-bonding processes. The shadow-masking combines deposition and patterning in one step thanks to spray-coating through a polymer microstencil that allows patterning of thermosensitive materials such as PMMA. The shadow-masking parameters have been optimized to obtain suspended microcantilevers characterized by a convenient thickness profile. The resulting PMMA structures were then transferred onto SU-8 chips by using an SU-8 wafer-bonding process. The effect of the UV exposure dose of both SU-8 layers in contact on the bonding quality has been investigated and optimized. With the optimized bonding process, we have achieved the large-scale transfer of microstructures with a yield of 100% and a bond strength of 50 MPa. These microcantilevers were also tested at resonance to determine Young's moduli of patterned polymers. The low values obtained (below 5 GPa) make these organic MEMS structures strong candidates for highly sensitive sensing applications when used in the static mode

  12. A novel signal amplification strategy of an electrochemical aptasensor for kanamycin, based on thionine functionalized graphene and hierarchical nanoporous PtCu.

    Science.gov (United States)

    Qin, Xiaoli; Yin, Yan; Yu, Huijing; Guo, Wenjuan; Pei, Meishan

    2016-03-15

    An ultrasensitive electrochemical aptasensor for the quantitative detection of kanamycin antibiotic was fabricated based on a novel signal amplification strategy. This aptasensor was developed using thionine functionalized graphene (GR-TH) and hierarchical nanoporous (HNP) PtCu alloy as biosensing substrates for the first time. HNP-PtCu alloy with controllable bimodal ligament/pore distributions was successfully prepared by two-step dealloying of a well-designed PtCuAl precursor alloy combined with an annealing operation. GR-TH composite was synthesized by one-step reduction of graphene oxide (GO) in TH solution. Greatly amplified sensitivity was achieved by using GR-TH/HNP-PtCu composite owing to its large specific surface and good electron-transfer ability. Under the optimized conditions, the proposed aptasensor exhibited a high sensitivity and a wider linearity to kanamycin in the range 5 × 10(-7)-5 × 10(-2) μgmL(-1) with a low detection limit of 0.42 pgmL(-1). This aptasensor also displayed a satisfying electrochemical performance with good stability, selectivity and reproducibility. The as-prepared aptasensor was successfully used for the determination of kanamycin in animal derived food. PMID:26513281

  13. Analysis hierarchical model for discrete event systems

    Science.gov (United States)

    Ciortea, E. M.

    2015-11-01

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

  14. Biased trapping issue on weighted hierarchical networks

    Indian Academy of Sciences (India)

    Meifeng Dai; Jie Liu; Feng Zhu

    2014-10-01

    In this paper, we present trapping issues of weight-dependent walks on weighted hierarchical networks which are based on the classic scale-free hierarchical networks. Assuming that edge’s weight is used as local information by a random walker, we introduce a biased walk. The biased walk is that a walker, at each step, chooses one of its neighbours with a probability proportional to the weight of the edge. We focus on a particular case with the immobile trap positioned at the hub node which has the largest degree in the weighted hierarchical networks. Using a method based on generating functions, we determine explicitly the mean first-passage time (MFPT) for the trapping issue. Let parameter (0 < < 1) be the weight factor. We show that the efficiency of the trapping process depends on the parameter a; the smaller the value of a, the more efficient is the trapping process.

  15. Incentive Mechanisms for Hierarchical Spectrum Markets

    CERN Document Server

    Iosifidis, George; Alpcan, Tansu; Koutsopoulos, Iordanis

    2011-01-01

    We study spectrum allocation mechanisms in hierarchical multi-layer markets which are expected to proliferate in the near future based on the current spectrum policy reform proposals. We consider a setting where a state agency sells spectrum to Primary Operators (POs) and in turn these resell it to Secondary Operators (SOs) through auctions. We show that these hierarchical markets do not result in a socially efficient spectrum allocation which is aimed by the agency, due to lack of coordination among the entities in different layers and the inherently selfish revenue-maximizing strategy of POs. In order to reconcile these opposing objectives, we propose an incentive mechanism which aligns the strategy and the actions of the POs with the objective of the agency, and thus it leads to system performance improvement in terms of social welfare. This pricing based mechanism constitutes a method for hierarchical market regulation and requires the feedback provision from SOs. A basic component of the proposed incenti...

  16. Negative Sequence Droop Method based Hierarchical Control for Low Voltage Ride-Through in Grid-Interactive Microgrids

    DEFF Research Database (Denmark)

    Zhao, Xin; Firoozabadi, Mehdi Savaghebi; Quintero, Juan Carlos Vasquez; Guerrero, Josep M.; Sun, Kai; Wu, Xiaohua; Chen, Guoliang; Sun, Libing

    this paper, a voltage support strategy based on negative sequence droop control, which regulate the positive/negative sequence active and reactive power flow by means of sending proper voltage reference to the inner control loop, is proposed for the grid connected MGs to ride through voltage sags under...... control loop consists of voltage and current inner loops, conventional droop control and virtual impedance loop while the secondary control loop is based on positive/negative sequence droop control which can achieve power injection under voltage sags. Experimental results with asymmetrical voltage sags...

  17. Hierarchical linear regression models for conditional quantiles

    Institute of Scientific and Technical Information of China (English)

    TIAN; Maozai

    2006-01-01

    The quantile regression has several useful features and therefore is gradually developing into a comprehensive approach to the statistical analysis of linear and nonlinear response models,but it cannot deal effectively with the data with a hierarchical structure.In practice,the existence of such data hierarchies is neither accidental nor ignorable,it is a common phenomenon.To ignore this hierarchical data structure risks overlooking the importance of group effects,and may also render many of the traditional statistical analysis techniques used for studying data relationships invalid.On the other hand,the hierarchical models take a hierarchical data structure into account and have also many applications in statistics,ranging from overdispersion to constructing min-max estimators.However,the hierarchical models are virtually the mean regression,therefore,they cannot be used to characterize the entire conditional distribution of a dependent variable given high-dimensional covariates.Furthermore,the estimated coefficient vector (marginal effects)is sensitive to an outlier observation on the dependent variable.In this article,a new approach,which is based on the Gauss-Seidel iteration and taking a full advantage of the quantile regression and hierarchical models,is developed.On the theoretical front,we also consider the asymptotic properties of the new method,obtaining the simple conditions for an n1/2-convergence and an asymptotic normality.We also illustrate the use of the technique with the real educational data which is hierarchical and how the results can be explained.

  18. Enhanced Deployment Strategy for Role-Based Hierarchical Application Agents in Wireless Sensor Networks with Established Clusterheads

    Science.gov (United States)

    Gendreau, Audrey

    2014-01-01

    Efficient self-organizing virtual clusterheads that supervise data collection based on their wireless connectivity, risk, and overhead costs, are an important element of Wireless Sensor Networks (WSNs). This function is especially critical during deployment when system resources are allocated to a subsequent application. In the presented research,…

  19. Hierarchical energy and frequency security pricing in a smart microgrid: An equilibrium-inspired epsilon constraint based multi-objective decision making approach

    International Nuclear Information System (INIS)

    Highlights: • Proposing a multi-objective security pricing mechanism for islanded microgrids. • Generating Pareto points using epsilon constraint methodology. • Best compromise solution using a novel decision making approach. • An equilibrium-inspired technique is used as an efficient decision making method. • Stochastic management of hierarchical reserves in a droop controlled microgrid. - Abstract: The present paper formulates a frequency security constrained energy management system for an islanded microgrid. Static and dynamic securities of the microgrids have been modeled in depth based on droop control paradigm. The derived frequency dependent modeling is incorporated into a multi-objective energy management system. Microgrid central controller is in charge to determine optimal prices of energy and frequency security such that technical, economic and environmental targets are satisfied simultaneously. The associated prices are extracted based on calculating related Lagrange multipliers corresponding to providing the microgrid hourly energy and reserve requirements. Besides, to generate optimal Pareto solutions of the proposed multi-objective framework augmented epsilon constraint method is applied. Moreover, a novel methodology on the basis of Nash equilibrium strategy is devised and employed to select the best compromise solution from the generated Pareto front. Comprehensive analysis tool is implemented in a typical test microgrid and executed over a 24 h scheduling time horizon. The energy, primary and secondary frequency control reserves have been scheduled appropriately in three different case-studies which are defined based on the microgrid various operational policies. The optimization results verify that the operational policies adopted by means of the microgrid central controller have direct impacts on determined energy and security prices. The illustrative implementations can give the microgrid central controller an insight view to provide

  20. HCTE: Hierarchical Clustering based routing algorithm with applying the Two cluster heads in each cluster for Energy balancing in WSN

    Directory of Open Access Journals (Sweden)

    Nasrin Azizi

    2012-01-01

    Full Text Available In wireless sensor networks, the energy constraint is one of the most important restrictions. With considering this issue, the energy balancing is essential for prolonging the network lifetime. Hence this problem has been considered as a main challenge in the research of scientific communities. In the recent papers many clustering based routing algorithms have been proposed to prolong the network lifetime in wireless sensor networks. But many of them not consider the energy balancing among nodes. In this work we propose the new clustering based routing protocol namely HCTE that cluster head selection mechanism in it is done in two separate stages. So there will be two cluster head in a cluster. The routing algorithm used in proposed protocol is multi hop. Simulation Results show that the HCTE prolongs the network lifetime about 35% compared to the LEACH.

  1. Nanorainforest solar cells based on multi-junction hierarchical p-Si/n-CdS/n-ZnO nanoheterostructures

    Science.gov (United States)

    Wang, Wei; Zhao, Qing; Laurent, Kevin; Leprince-Wang, Y.; Liao, Zhi-Min; Yu, Dapeng

    2011-12-01

    Solar cells based on one-dimensional nanostructures have recently emerged as one of the most promising candidates to achieve high-efficiency solar energy conversion due to their reduced optical reflection, enhanced light absorption, and enhanced carrier collection. In nature, the rainforest, consisting of several stereo layers of vegetation, is the highest solar-energy-using ecosystem. Herein, we gave an imitation of the rainforest configuration in nanostructure-based solar cell design. Novel multi-layer nanorainforest solar cells based on p-Si nanopillar array/n-CdS nanoparticles/n-ZnO nanowire array heterostructures were achieved via a highly accessible, reproducible and controllable fabrication process. By choosing materials with appropriate bandgaps, an efficient light absorption and enhanced light harvesting were achieved due to the wide range of the solar spectrum covered. Si nanopillar arrays were introduced as direct conduction pathways for photon-generated charges' efficient collection and transport. The unique strategy using PMMA as a void-filling material to obtain a continuous, uniform and low resistance front electrode has significantly improved the overall light conversion efficiency by two orders of magnitude. These results demonstrate that nanorainforest solar cells, along with wafer-scale, low-cost and easily controlled processing, open up substantial opportunities for nanostructure photovoltaic devices.Solar cells based on one-dimensional nanostructures have recently emerged as one of the most promising candidates to achieve high-efficiency solar energy conversion due to their reduced optical reflection, enhanced light absorption, and enhanced carrier collection. In nature, the rainforest, consisting of several stereo layers of vegetation, is the highest solar-energy-using ecosystem. Herein, we gave an imitation of the rainforest configuration in nanostructure-based solar cell design. Novel multi-layer nanorainforest solar cells based on p

  2. Hierarchical Object-Based Mapping of Riverscape Units and in-Stream Mesohabitats Using LiDAR and VHR Imagery

    Directory of Open Access Journals (Sweden)

    Luca Demarchi

    2016-01-01

    Full Text Available In this paper, we present a new, semi-automated methodology for mapping hydromorphological indicators of rivers at a regional scale using multisource remote sensing (RS data. This novel approach is based on the integration of spectral and topographic information within a multilevel, geographic, object-based image analysis (GEOBIA. Different segmentation levels were generated based on the two sources of Remote Sensing (RS data, namely very-high spatial resolution, near-infrared imagery (VHR and high-resolution LiDAR topography. At each level, different input object features were tested with Machine Learning classifiers for mapping riverscape units and in-stream mesohabitats. The GEOBIA approach proved to be a powerful tool for analyzing the river system at different levels of detail and for coupling spectral and topographic datasets, allowing for the delineation of the natural fluvial corridor with its primary riverscape units (e.g., water channel, unvegetated sediment bars, riparian densely-vegetated units, etc. and in-stream mesohabitats with a high level of accuracy, respectively of K = 0.91 and K = 0.83. This method is flexible and can be adapted to different sources of data, with the potential to be implemented at regional scales in the future. The analyzed dataset, composed of VHR imagery and LiDAR data, is nowadays increasingly available at larger scales, notably through European Member States. At the same time, this methodology provides a tool for monitoring and characterizing the hydromorphological status of river systems continuously along the entire channel network and coherently through time, opening novel and significant perspectives to river science and management, notably for planning and targeting actions.

  3. Nested Hierarchical Dirichlet Processes.

    Science.gov (United States)

    Paisley, John; Wang, Chong; Blei, David M; Jordan, Michael I

    2015-02-01

    We develop a nested hierarchical Dirichlet process (nHDP) for hierarchical topic modeling. The nHDP generalizes the nested Chinese restaurant process (nCRP) to allow each word to follow its own path to a topic node according to a per-document distribution over the paths on a shared tree. This alleviates the rigid, single-path formulation assumed by the nCRP, allowing documents to easily express complex thematic borrowings. We derive a stochastic variational inference algorithm for the model, which enables efficient inference for massive collections of text documents. We demonstrate our algorithm on 1.8 million documents from The New York Times and 2.7 million documents from Wikipedia. PMID:26353240

  4. Hierarchical Work-Stealing

    OpenAIRE

    Quintin, Jean-Noel; Wagner, Frédéric

    2009-01-01

    In this paper, we study the problem of dynamic load-balancing on heterogeneous hierarchical platforms. In particular, we consider here applications involving heavy communications on a distributed platform. The work-stealing algorithm introduced by Blumofe and Leiserson is a commonly used technique to distribute load in a distributed environment but it suffers from poor performances in some cases of communications-intensive applications. We present here several variants of this algorithm found...

  5. Hierarchical Reinforcement Learning

    OpenAIRE

    Borga, Magnus

    1993-01-01

    A hierarchical representation of the input-output transition function in a learning system is suggested. The choice of either representing the knowledge in a learning system as a discrete set of input-output pairs or as a continuous input-output transition function is discussed. The conclusion that both representations could be efficient, but at different levels of abstraction is made. The difference between strategies and actions is defined. An algorithm for using adaptive critic methods in ...

  6. Data Driven Hierarchical Serial Scene Classification Framework

    Institute of Scientific and Technical Information of China (English)

    FENG Wen-Gang

    2014-01-01

    Scene classification is a complicated task, because it includes much content and it is difficult to capture its distribution. A novel hierarchical serial scene classification framework is presented in this paper. At first, we use hierarchical feature to present both the global scene and local patches containing specific objects. Hierarchy is presented by space pyramid match, and our own codebook is built by two different types of words. Secondly, we train the visual words by generative and discriminative methods respectively based on space pyramid match, which could obtain the local patch labels efficiently. Then, we use a neural network to simulate the human decision process, which leads to the final scene category from local labels. Experiments show that the hierarchical serial scene image representation and classification model obtains superior results with respect to accuracy.

  7. Hierarchic Models of Turbulence, Superfluidity and Superconductivity

    CERN Document Server

    Kaivarainen, A

    2000-01-01

    New models of Turbulence, Superfluidity and Superconductivity, based on new Hierarchic theory, general for liquids and solids (physics/0102086), have been proposed. CONTENTS: 1 Turbulence. General description; 2 Mesoscopic mechanism of turbulence; 3 Superfluidity. General description; 4 Mesoscopic scenario of fluidity; 5 Superfluidity as a hierarchic self-organization process; 6 Superfluidity in 3He; 7 Superconductivity: General properties of metals and semiconductors; Plasma oscillations; Cyclotron resonance; Electroconductivity; 8. Microscopic theory of superconductivity (BCS); 9. Mesoscopic scenario of superconductivity: Interpretation of experimental data in the framework of mesoscopic model of superconductivity.

  8. Hierarchically Structured Electrospun Fibers

    Directory of Open Access Journals (Sweden)

    Nicole E. Zander

    2013-01-01

    Full Text Available Traditional electrospun nanofibers have a myriad of applications ranging from scaffolds for tissue engineering to components of biosensors and energy harvesting devices. The generally smooth one-dimensional structure of the fibers has stood as a limitation to several interesting novel applications. Control of fiber diameter, porosity and collector geometry will be briefly discussed, as will more traditional methods for controlling fiber morphology and fiber mat architecture. The remainder of the review will focus on new techniques to prepare hierarchically structured fibers. Fibers with hierarchical primary structures—including helical, buckled, and beads-on-a-string fibers, as well as fibers with secondary structures, such as nanopores, nanopillars, nanorods, and internally structured fibers and their applications—will be discussed. These new materials with helical/buckled morphology are expected to possess unique optical and mechanical properties with possible applications for negative refractive index materials, highly stretchable/high-tensile-strength materials, and components in microelectromechanical devices. Core-shell type fibers enable a much wider variety of materials to be electrospun and are expected to be widely applied in the sensing, drug delivery/controlled release fields, and in the encapsulation of live cells for biological applications. Materials with a hierarchical secondary structure are expected to provide new superhydrophobic and self-cleaning materials.

  9. Graph Representation for Objects Based on Hierarchical Decomposition of Skeletons%基于骨架层次分解的目标的图表示

    Institute of Scientific and Technical Information of China (English)

    刘俊义; 王润生

    2001-01-01

    Skeleton-based object representation techniques are of importance in pattern recognition and computer vision. Many skeletonization algorithms have been proposed in recent years. However the studies on how to use skeleton information to represent and recognize objects are very limited. Ablameyko et al.[1] presented an algorithm to construct the hierarchical structure graph of the object by decomposition of the distance-labeled skeleton into its meaningful structure elements. This graph can exactly describe the topological relationship of its structure elements. However it is sensitive to the noise in the skeleton, for example, the noise elements can destroy the integrality of the other elements and the stability of the graph. In order to overcome these drawbacks, an improvement strategy is presented in this paper which employs a skeleton-branches-grouping procedure and a multi-scale hierarchical structure graph constructing procedure. It has been shown that the resultant graph has fewer and more notable nodes and its structure is more stable than before. This graph can greatly improve the efficiency of the following inexact graph matching procedure. This technique has been applied in a shape feature based image database retrieval system.%基于骨架的目标表示技术是模式识别和计算机视觉的重要研究内容,近年来人们提出了许多骨架化算法,但是有关利用骨架信息表示并识别目标的研究还非常有限.Ablameyko等1996年提出了通过分解由距离标号的骨架为有意义的结构基元从而获得目标的层次结构图的方法.该图可以准确地刻画基元之间的拓扑关系,但是它对于骨架中的噪声比较敏感.主要表现为噪声基元破坏其它基元的完整性和图的稳定性.该文采用将分支编组为分支链以及构造多尺度层次结构图的改进策略来克服这些缺点,最终获得了目标的节点数更小、节点显著度更高、节点间连接关

  10. A hierarchical model for ordinal matrix factorization

    DEFF Research Database (Denmark)

    Paquet, Ulrich; Thomson, Blaise; Winther, Ole

    2012-01-01

    This paper proposes a hierarchical probabilistic model for ordinal matrix factorization. Unlike previous approaches, we model the ordinal nature of the data and take a principled approach to incorporating priors for the hidden variables. Two algorithms are presented for inference, one based on...

  11. Complex Evaluation of Hierarchically-Network Systems

    CERN Document Server

    Polishchuk, Dmytro; Yadzhak, Mykhailo

    2016-01-01

    Methods of complex evaluation based on local, forecasting, aggregated, and interactive evaluation of the state, function quality, and interaction of complex system's objects on the all hierarchical levels is proposed. Examples of analysis of the structural elements of railway transport system are used for illustration of efficiency of proposed approach.

  12. The Supervised Hierarchical Dirichlet Process.

    Science.gov (United States)

    Dai, Andrew M; Storkey, Amos J

    2015-02-01

    We propose the supervised hierarchical Dirichlet process (sHDP), a nonparametric generative model for the joint distribution of a group of observations and a response variable directly associated with that whole group. We compare the sHDP with another leading method for regression on grouped data, the supervised latent Dirichlet allocation (sLDA) model. We evaluate our method on two real-world classification problems and two real-world regression problems. Bayesian nonparametric regression models based on the Dirichlet process, such as the Dirichlet process-generalised linear models (DP-GLM) have previously been explored; these models allow flexibility in modelling nonlinear relationships. However, until now, hierarchical Dirichlet process (HDP) mixtures have not seen significant use in supervised problems with grouped data since a straightforward application of the HDP on the grouped data results in learnt clusters that are not predictive of the responses. The sHDP solves this problem by allowing for clusters to be learnt jointly from the group structure and from the label assigned to each group. PMID:26353239

  13. Hierarchical classification of glycoside hydrolases.

    Science.gov (United States)

    Naumoff, D G

    2011-06-01

    This review deals with structural and functional features of glycoside hydrolases, a widespread group of enzymes present in almost all living organisms. Their catalytic domains are grouped into 120 amino acid sequence-based families in the international classification of the carbohydrate-active enzymes (CAZy database). At a higher hierarchical level some of these families are combined in 14 clans. Enzymes of the same clan have common evolutionary origin of their genes and share the most important functional characteristics such as composition of the active center, anomeric configuration of cleaved glycosidic bonds, and molecular mechanism of the catalyzed reaction (either inverting, or retaining). There are now extensive data in the literature concerning the relationship between glycoside hydrolase families belonging to different clans and/or included in none of them, as well as information on phylogenetic protein relationship within particular families. Summarizing these data allows us to propose a multilevel hierarchical classification of glycoside hydrolases and their homologs. It is shown that almost the whole variety of the enzyme catalytic domains can be brought into six main folds, large groups of proteins having the same three-dimensional structure and the supposed common evolutionary origin. PMID:21639842

  14. The STAR concept: A hierarchical hub-spoke nuclear architecture based on long refuelling interval battery reactors and regional fuel cycle centers

    International Nuclear Information System (INIS)

    The STAR reactor and fuel cycle concept is devised to attain Gen-IV goals by responding to foreseen mid century needs and market conditions. It is targeted to fill energy and potable water needs for urban centres in developing countries and is designed to fit within a hierarchical hub-spoke energy architecture based on regional fuel cycle centres, using nuclear fuel as the long distance energy carrier - with distributed electricity generation as the local carrier to mesh with existing urban energy distribution infrastructures using grid delivery of electricity, potable water, and communications (and sewage return) through a common grid of easements. STAR is also intended for Independent Power Producers in industrialized countries seeking to service emerging markets for hydrogen and water production. STAR concept development is being conducted for a portfolio of specific reactor and balance of plant designs to enable an incremental market penetration that is time-phased according to the degree of R and D required. STAR-LM is a Pb-cooled, 400 MWth, natural circulation reactor of 565 deg. C core outlet temperature driving a supercritical CO2 Brayton cycle for electricity production. It draws on many proven technologies and will be ready for market in 15-20 years. STAR-H2 raises the Pb outlet temperature to 800 deg. C to drive a thermochemical water cracking cycle and will require additional R and D. SSTAR takes the STAR-LM design features down to ∼25 to 50 MWth for secure energy supply to remote small villages. All STAR concepts are designed for 20-year refuelling interval and rely on out-sourcing fuel cycle and waste management services to proposed regional fuel cycle centres. All employ desalination (or alterative) bottoming cycles to extend their scope of energy services and to minimize their environmental footprint. (author)

  15. Hierarchical LiFePO4 with a controllable growth of the (010) facet for lithium-ion batteries

    OpenAIRE

    Binbin Guo; Hongcheng Ruan; Cheng Zheng; Hailong Fei; Mingdeng Wei

    2013-01-01

    Hierarchically structured LiFePO4 was successfully synthesized by ionic liquid solvothermal method. These hierarchically structured LiFePO4 samples were constructed from nanostructured platelets with their (010) facets mainly exposed. To the best of our knowledge, facet control of a hierarchical LiFePO4 crystal has not been reported yet. Based on a series of experimental results, a tentative mechanism for the formation of these hierarchical structures was proposed. After these hierarchically ...

  16. A facile approach for the synthesis of monolithic hierarchical porous carbons – high performance materials for amine based CO2 capture and supercapacitor electrode

    KAUST Repository

    Estevez, Luis

    2013-05-03

    An ice templating coupled with hard templating and physical activation approach is reported for the synthesis of hierarchically porous carbon monoliths with tunable porosities across all three length scales (macro- meso- and micro), with ultrahigh specific pore volumes [similar]11.4 cm3 g−1. The materials function well as amine impregnated supports for CO2 capture and as supercapacitor electrodes.

  17. Detecting Hierarchical Structure in Networks

    DEFF Research Database (Denmark)

    Herlau, Tue; Mørup, Morten; Schmidt, Mikkel Nørgaard;

    2012-01-01

    Many real-world networks exhibit hierarchical organization. Previous models of hierarchies within relational data has focused on binary trees; however, for many networks it is unknown whether there is hierarchical structure, and if there is, a binary tree might not account well for it. We propose....... On synthetic and real data we demonstrate that our model can detect hierarchical structure leading to better link-prediction than competing models. Our model can be used to detect if a network exhibits hierarchical structure, thereby leading to a better comprehension and statistical account the network....

  18. Improved Adhesion and Compliancy of Hierarchical Fibrillar Adhesives.

    Science.gov (United States)

    Li, Yasong; Gates, Byron D; Menon, Carlo

    2015-08-01

    The gecko relies on van der Waals forces to cling onto surfaces with a variety of topography and composition. The hierarchical fibrillar structures on their climbing feet, ranging from mesoscale to nanoscale, are hypothesized to be key elements for the animal to conquer both smooth and rough surfaces. An epoxy-based artificial hierarchical fibrillar adhesive was prepared to study the influence of the hierarchical structures on the properties of a dry adhesive. The presented experiments highlight the advantages of a hierarchical structure despite a reduction of overall density and aspect ratio of nanofibrils. In contrast to an adhesive containing only nanometer-size fibrils, the hierarchical fibrillar adhesives exhibited a higher adhesion force and better compliancy when tested on an identical substrate. PMID:26167951

  19. Adaptive Sampling in Hierarchical Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Knap, J; Barton, N R; Hornung, R D; Arsenlis, A; Becker, R; Jefferson, D R

    2007-07-09

    We propose an adaptive sampling methodology for hierarchical multi-scale simulation. The method utilizes a moving kriging interpolation to significantly reduce the number of evaluations of finer-scale response functions to provide essential constitutive information to a coarser-scale simulation model. The underlying interpolation scheme is unstructured and adaptive to handle the transient nature of a simulation. To handle the dynamic construction and searching of a potentially large set of finer-scale response data, we employ a dynamic metric tree database. We study the performance of our adaptive sampling methodology for a two-level multi-scale model involving a coarse-scale finite element simulation and a finer-scale crystal plasticity based constitutive law.

  20. Hierarchical networks of scientific journals

    CERN Document Server

    Palla, Gergely; Mones, Enys; Pollner, Péter; Vicsek, Tamás

    2015-01-01

    Scientific journals are the repositories of the gradually accumulating knowledge of mankind about the world surrounding us. Just as our knowledge is organised into classes ranging from major disciplines, subjects and fields to increasingly specific topics, journals can also be categorised into groups using various metrics. In addition to the set of topics characteristic for a journal, they can also be ranked regarding their relevance from the point of overall influence. One widespread measure is impact factor, but in the present paper we intend to reconstruct a much more detailed description by studying the hierarchical relations between the journals based on citation data. We use a measure related to the notion of m-reaching centrality and find a network which shows the level of influence of a journal from the point of the direction and efficiency with which information spreads through the network. We can also obtain an alternative network using a suitably modified nested hierarchy extraction method applied ...

  1. A Hierarchical Modular Echo State Network Based on Brain Networks%一种基于脑网络的分层模块化回声状态网络

    Institute of Scientific and Technical Information of China (English)

    李丁园; 刘富; 乔俊飞

    2015-01-01

    For the structure design of echo state network (ESN), a novel hierarchical modular echo state network (HMESN) based on brain networks is established. The topology of brain networks makes functional networks with rich dynamic behavior. Therefore, from a biological bionic point of view, the reservoir of HMESN for hierarchical design, each level of neurons using small world network construction algorithm to generate modular structure, as well as considered the hierarchical connection .Based on the topological characteristics of hierarchical modular in brain network, it weakens the coupling intensity among neurons, and enriches the dynamics of internal neurons. HMESN's reservoir is closer to the real biological neural networks from both structural and functional perspectives, which effectively improves the information processing ability of network. Finally, this proposed network is used for the Mackey-Glass time series prediction and the non-linear system identification to prove its validity and feasibility.%针对回声状态网络(Echo state network, ESN)结构设计问题,提出一种基于脑网络的分层模块化回声状态网络(Hierarchical modular echo state network, HMESN).脑网络的拓扑结构使功能网络具有丰富的动力学特性,因此,从生物仿生学角度出发,对HMESN的储备池进行分层设计,各层级上的神经元采用小世界网络构建算法生成模块化结构,并引入层级连接.基于脑网络分层模块化的拓扑特征弱化了神经元间的耦合程度,从而使神经元的动力学特性更为丰富,在功能与结构上更接近于真实生物神经网络,有效地提高了网络处理问题的能力.采用 Mackey-Glass 时间序列预测和非线性系统辨识对网络进行验证,证明该网络的有效性和可行性.

  2. Construction of hierarchical diagnosis network based on deep learning and its application in the fault pattern recognition of rolling element bearings

    Science.gov (United States)

    Gan, Meng; Wang, Cong; Zhu, Chang`an

    2016-05-01

    A novel hierarchical diagnosis network (HDN) is proposed by collecting deep belief networks (DBNs) by layer for the hierarchical identification of mechanical system. The deeper layer in HDN presents a more detailed classification of the result generated from the last layer to provide representative features for different tasks. A two-layer HDN is designed for a two-stage diagnosis with the wavelet packet energy feature. The first layer is intended to identify fault types, while the second layer is developed to further recognize fault severity ranking from the result of the first layer. To confirm the effectiveness of HDN, two similar networks constructed by support vector machine and back propagation neuron networks (BPNN) are employed to present a comprehensive comparison. The experimental results show that HDN is highly reliable for precise multi-stage diagnosis and can overcome the overlapping problem caused by noise and other disturbances.

  3. Hierarchical, Hybrid Control Of Large Scale Systems

    OpenAIRE

    Lygeros, John

    1996-01-01

    This dissertation presents a hierarchical, hybrid point of view to the control of large-scale systems. The analysis is based on a new hybrid dynamical system formulation that allows for the modelling of large scale systems in a modular fashion. Three problems are addressed: controller design, closed loop performance verification and the extension of system autonomy. A control scheme based on semi-autonomous agent operation is first proposed. An algorithm, using ideas from game theory, is pres...

  4. Strategic games on a hierarchical network model

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Among complex network models, the hierarchical network model is the one most close to such real networks as world trade web, metabolic network, WWW, actor network, and so on. It has not only the property of power-law degree distribution, but growth based on growth and preferential attachment, showing the scale-free degree distribution property. In this paper, we study the evolution of cooperation on a hierarchical network model, adopting the prisoner's dilemma (PD) game and snowdrift game (SG) as metaphors of the interplay between connected nodes. BA model provides a unifying framework for the emergence of cooperation. But interestingly, we found that on hierarchical model, there is no sign of cooperation for PD game, while the frequency of cooperation decreases as the common benefit decreases for SG. By comparing the scaling clustering coefficient properties of the hierarchical network model with that of BA model, we found that the former amplifies the effect of hubs. Considering different performances of PD game and SG on complex network, we also found that common benefit leads to cooperation in the evolution. Thus our study may shed light on the emergence of cooperation in both natural and social environments.

  5. Roughly Weighted Hierarchical Simple Games

    OpenAIRE

    Hameed, Ali; Slinko, Arkadii

    2012-01-01

    Hierarchical simple games - both disjunctive and conjunctive - are natural generalizations of simple majority games. They take their origin in the theory of secret sharing. Another important generalization of simple majority games with origin in economics and politics are weighted and roughly weighted majority games. In this paper we characterize roughly weighted hierarchical games identifying where the two approaches coincide.

  6. Trees and Hierarchical Structures

    CERN Document Server

    Haeseler, Arndt

    1990-01-01

    The "raison d'etre" of hierarchical dustering theory stems from one basic phe­ nomenon: This is the notorious non-transitivity of similarity relations. In spite of the fact that very often two objects may be quite similar to a third without being that similar to each other, one still wants to dassify objects according to their similarity. This should be achieved by grouping them into a hierarchy of non-overlapping dusters such that any two objects in ~ne duster appear to be more related to each other than they are to objects outside this duster. In everyday life, as well as in essentially every field of scientific investigation, there is an urge to reduce complexity by recognizing and establishing reasonable das­ sification schemes. Unfortunately, this is counterbalanced by the experience of seemingly unavoidable deadlocks caused by the existence of sequences of objects, each comparatively similar to the next, but the last rather different from the first.

  7. 基于层级化身份的可证明安全的认证密钥协商协议%Provably Secure Authenticated Key Agreement Protocol Based on Hierarchical Identity

    Institute of Scientific and Technical Information of China (English)

    曹晨磊; 刘明奇; 张茹; 杨义先

    2014-01-01

    目前基于身份的认证密钥协商协议均以单个私钥生成器(PKG)为可信第三方,但这种系统结构难以满足身份分层注册与认证需求。该文以基于层级化身份的加密(HIBE)系统为基础重构了私钥的组成元素,并利用椭圆曲线乘法循环群上的双线性映射提出一个基于层级化身份的认证密钥协商协议,为隶属于不同层级的云实体提供了安全的会话密钥协商机制。基于CDH(Computational Diffie-Hellman)与GDH(Gap Diffie-Hellman)假设,该文证明了新协议在eCK模型下具有已知密钥安全性、前向安全性和PKG前向安全性,并且能够抵抗基于密钥泄露的伪装攻击。%At present most Identity-based authenticated key agreement protocols are built on the security infrastructure in which a single Private Key Generator (PKG) is contained as the only trusted third party of the whole system, however such kind of infrastructure can not satisfy the requirements of hierarchical identity register and authentication. On the basis of Hierarchical Identity Based Encryption (HIBE) system, this paper reconstructs the private key and proposes a new hierarchical identity based authenticated key agreement protocol using the bilinear map in multiplicative cyclic group and it provides secure session key exchange mechanism for cloud entities on different hierarchical levels. Based on the Computational Diffie-Hellman (CDH) and Gap Diffie-Hellman (GDH) assumptions, this paper proves that the new protocol not only achieves known-key security, forward secrecy and PKG forward secrecy, but also resists key-compromise impersonation attacks in the eCK model.

  8. Provably Secure Authenticated Key Agreement Protocol Based on Hierarchical Identity%基于层级化身份的可证明安全的认证密钥协商协议

    Institute of Scientific and Technical Information of China (English)

    曹晨磊; 刘明奇; 张茹; 杨义先

    2014-01-01

    目前基于身份的认证密钥协商协议均以单个私钥生成器(PKG)为可信第三方,但这种系统结构难以满足身份分层注册与认证需求。该文以基于层级化身份的加密(HIBE)系统为基础重构了私钥的组成元素,并利用椭圆曲线乘法循环群上的双线性映射提出一个基于层级化身份的认证密钥协商协议,为隶属于不同层级的云实体提供了安全的会话密钥协商机制。基于CDH(Computational Diffie-Hellman)与GDH(Gap Diffie-Hellman)假设,该文证明了新协议在eCK模型下具有已知密钥安全性、前向安全性和PKG前向安全性,并且能够抵抗基于密钥泄露的伪装攻击。%At present most Identity-based authenticated key agreement protocols are built on the security infrastructure in which a single Private Key Generator (PKG) is contained as the only trusted third party of the whole system, however such kind of infrastructure can not satisfy the requirements of hierarchical identity register and authentication. On the basis of Hierarchical Identity Based Encryption (HIBE) system, this paper reconstructs the private key and proposes a new hierarchical identity based authenticated key agreement protocol using the bilinear map in multiplicative cyclic group and it provides secure session key exchange mechanism for cloud entities on different hierarchical levels. Based on the Computational Diffie-Hellman (CDH) and Gap Diffie-Hellman (GDH) assumptions, this paper proves that the new protocol not only achieves known-key security, forward secrecy and PKG forward secrecy, but also resists key-compromise impersonation attacks in the eCK model.

  9. Hierarchical Case-Based Reasoning: Integrating Case-Based and Decompositional Problem-Solving Techniques for Plant-Control Software Design

    OpenAIRE

    Smyth, Barry; Cunningham, Padraig; Keane, Mark T.

    1997-01-01

    Case-based reasoning (CBR) is an AI technique that emphasises the role of past experience during future problem solving. New problems are solved by retrieving and adapting the solutions to similar problems, solutions that have been stored and indexed for future reuse as cases in a case-base. The power of CBR is severely curtailed if problem solving is limited to the retrieval and adaptation of a single case, and for this reason the strategy of reusing multiple cases is immediately...

  10. Free-standing iridium and rhodium-based hierarchically-coiled ultrathin nanosheets for highly selective reduction of nitrobenzene to azoxybenzene under ambient conditions.

    Science.gov (United States)

    Zhang, Zhi-Ping; Wang, Xin-Yu; Yuan, Kun; Zhu, Wei; Zhang, Tao; Wang, Yu-Hao; Ke, Jun; Zheng, Xiao-Yu; Yan, Chun-Hua; Zhang, Ya-Wen

    2016-08-25

    The fabrication of atom-layered two dimensional (2D) noble metal nanosheets (NSs) in a face-centered cubic (fcc) structure is of broad scientific and technological importance, yet this remains a challenge due to the intrinsic cubic symmetry and high surface energy of fcc noble metals. Herein, we report a solid-liquid interface mediated 2D growth method towards the synthesis of hierarchically-coiled ultrathin Ir NSs (thickness alkaline conditions, as indicated by density functional theory (DFT) calculations. PMID:27526938

  11. Ultrasensitive non-enzymatic glucose sensor based on three-dimensional network of ZnO-CuO hierarchical nanocomposites by electrospinning

    OpenAIRE

    Chunyang Zhou; Lin Xu; Jian Song; Ruiqing Xing; Sai Xu; Dali Liu; Hongwei Song

    2014-01-01

    Three-dimensional (3D) porous ZnO–CuO hierarchical nanocomposites (HNCs) nonenzymatic glucose electrodes with different thicknesses were fabricated by coelectrospinning and compared with 3D mixed ZnO/CuO nanowires (NWs) and pure CuO NWs electrodes. The structural characterization revealed that the ZnO–CuO HNCs were composed of the ZnO and CuO mixed NWs trunk (~200 nm), whose outer surface was attached with small CuO nanoparticles (NPs). Moreover, a good synergetic effect between CuO and ZnO w...

  12. Communication Situations with a Hierarchical Player Partition

    OpenAIRE

    Slikker, M.; van den Nouweland, C.G.A.M.

    1996-01-01

    In this paper we study situations where agents who are divided in hierarchical classes have restricted possibilities for communication. We introduce a class of allocation rules for these situations inspired by the Myerson value (Myerson (1977)) and Shapley values with weight systems (Kalai and Samet (1988)). It is shown that this new class of allocation rules can be characterized by a consistency property, a fairness criterion, a property based on the hierarchy among the agents, and an ecienc...

  13. Parallel Hierarchical Radiosity for Complex Building Interiors

    OpenAIRE

    Meneveaux, Daniel; Bouatouch, Kadi

    1998-01-01

    In this paper we propose a SPMD parallel hierarchical radiosity algorithm relying on a novel partitioning method which may apply to any kind of architectural scene, not necessarly axial. This algorithm is based on a public domain software called MPI (Message Passing Interface) which allows the use of either a heterogeneous set of concurrent computers or a parallel computer or both. The database is stored on a single disk and accessed by all the processors (through NFS in case of a network of ...

  14. The Infinite Hierarchical Factor Regression Model

    CERN Document Server

    Rai, Piyush

    2009-01-01

    We propose a nonparametric Bayesian factor regression model that accounts for uncertainty in the number of factors, and the relationship between factors. To accomplish this, we propose a sparse variant of the Indian Buffet Process and couple this with a hierarchical model over factors, based on Kingman's coalescent. We apply this model to two problems (factor analysis and factor regression) in gene-expression data analysis.

  15. Hierarchical reinforcement learning for communicating agents

    OpenAIRE

    Rovatsos, Michael; Fischer, Felix; Weiss, Gerhard

    2004-01-01

    This paper proposes hierarchical reinforcement learning (RL) methods for communication in multiagent coordination problems modelled as Markov Decision Processes (MDPs). To bridge the gap between the MDP view and the methods used to specify communication protocols in multiagent systems (using logical conditions and propositional message structure), we utilise interaction frames as powerful policy abstractions that can be combined with case-based reasoning techniques. Also, we exploit the fact ...

  16. Hierarchical optimization for neutron scattering problems

    Science.gov (United States)

    Bao, Feng; Archibald, Rick; Bansal, Dipanshu; Delaire, Olivier

    2016-06-01

    We present a scalable optimization method for neutron scattering problems that determines confidence regions of simulation parameters in lattice dynamics models used to fit neutron scattering data for crystalline solids. The method uses physics-based hierarchical dimension reduction in both the computational simulation domain and the parameter space. We demonstrate for silicon that after a few iterations the method converges to parameters values (interatomic force-constants) computed with density functional theory simulations.

  17. Multicriteria Evaluation and Optimization of Hierarchical Systems

    OpenAIRE

    Voronin, Albert

    2008-01-01

    It is shown that any multicriteria problem can be represented by a hierarchical system. Separate properties of the object are evaluated at the lower level of the system, using a criteria vector, and a composition mechanism is used to evaluate the object as a whole at the upper level. The paper proposes a method to solve complex multicriteria problems of evaluation and optimization. It is based on nested scalar convolutions of vector- valued criteria and allows simple structural...

  18. Modeling the deformation behavior of nanocrystalline alloy with hierarchical microstructures

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hongxi; Zhou, Jianqiu, E-mail: zhouj@njtech.edu.cn [Nanjing Tech University, Department of Mechanical Engineering (China); Zhao, Yonghao, E-mail: yhzhao@njust.edu.cn [Nanjing University of Science and Technology, Nanostructural Materials Research Center, School of Materials Science and Engineering (China)

    2016-02-15

    A mechanism-based plasticity model based on dislocation theory is developed to describe the mechanical behavior of the hierarchical nanocrystalline alloys. The stress–strain relationship is derived by invoking the impeding effect of the intra-granular solute clusters and the inter-granular nanostructures on the dislocation movements along the sliding path. We found that the interaction between dislocations and the hierarchical microstructures contributes to the strain hardening property and greatly influence the ductility of nanocrystalline metals. The analysis indicates that the proposed model can successfully describe the enhanced strength of the nanocrystalline hierarchical alloy. Moreover, the strain hardening rate is sensitive to the volume fraction of the hierarchical microstructures. The present model provides a new perspective to design the microstructures for optimizing the mechanical properties in nanostructural metals.

  19. One-Pot Fabrication of Hierarchical Nanosheet-Based TiO2 -Carbon Hollow Microspheres for Anode Materials of High-Rate Lithium-Ion Batteries.

    Science.gov (United States)

    Jin, Zhaokui; Yang, Mu; Wang, Jingjing; Gao, Hongyi; Lu, Yunfeng; Wang, Ge

    2016-04-18

    Hierarchical and hollow nanostructures have recently attracted considerable attention because of their fantastic architectures and tunable property for facile lithium ion insertion and good cycling stability. In this study, a one-pot and unusual carving protocol is demonstrated for engineering hollow structures with a porous shell. Hierarchical TiO2 hollow spheres with nanosheet-assembled shells (TiO2 NHS) were synthesized by the sequestration between the titanium source and 2,2'-bipyridine-5,5'-dicarboxylic acid, and kinetically controlled etching in trifluoroacetic acid medium. In addition, annealing such porous nanostructures presents the advantage of imparting carbon-doped functional performance to its counterpart under different atmospheres. Such highly porous structures endow very large specifics surface area of 404 m(2)  g(-1) and 336 m(2)  g(-1) for the as-prepared and calcination under nitrogen gas. C/TiO2 NHS has high capacity of 204 mA h g(-1) at 1 C and a reversible capacity of 105 mA h g(-1) at a high rate of 20 C, and exhibits good cycling stability and superior rate capability as an anode material for lithium-ion batteries. PMID:26970239

  20. Adapting hierarchical bidirectional inter prediction on a GPU-based platform for 2D and 3D H.264 video coding

    Science.gov (United States)

    Rodríguez-Sánchez, Rafael; Martínez, José Luis; Cock, Jan De; Fernández-Escribano, Gerardo; Pieters, Bart; Sánchez, José L.; Claver, José M.; de Walle, Rik Van

    2013-12-01

    The H.264/AVC video coding standard introduces some improved tools in order to increase compression efficiency. Moreover, the multi-view extension of H.264/AVC, called H.264/MVC, adopts many of them. Among the new features, variable block-size motion estimation is one which contributes to high coding efficiency. Furthermore, it defines a different prediction structure that includes hierarchical bidirectional pictures, outperforming traditional Group of Pictures patterns in both scenarios: single-view and multi-view. However, these video coding techniques have high computational complexity. Several techniques have been proposed in the literature over the last few years which are aimed at accelerating the inter prediction process, but there are no works focusing on bidirectional prediction or hierarchical prediction. In this article, with the emergence of many-core processors or accelerators, a step forward is taken towards an implementation of an H.264/AVC and H.264/MVC inter prediction algorithm on a graphics processing unit. The results show a negligible rate distortion drop with a time reduction of up to 98% for the complete H.264/AVC encoder.

  1. The New Model of Chemical Evolution of r-process Elements Based on The Hierarchical Galaxy Formation I: Ba and Eu

    CERN Document Server

    Komiya, Yutaka; Suda, Takuma; Fujimoto, Masayuki Y

    2014-01-01

    We investigate the chemical enrichment of r-process elements in the early evolutionary stages of the Milky Way halo within the framework of hierarchical galaxy formation using a semi-analytic merger tree. In this paper, we focus on heavy r-process elements, Ba and Eu, of extremely metal-poor (EMP) stars and give constraints on their astronomical sites. Our models take into account changes of the surface abundances of EMP stars by the accretion of interstellar matter (ISM). We also consider metal-enrichment of intergalactic medium (IGM) by galactic winds and the resultant pre-enrichment of proto-galaxies. The trend and scatter of the observed r-process abundances are well reproduced by our hierarchical model with $\\sim 10\\%$ of core-collapse supernovae in low-mass end ($\\sim 10M_{\\odot}$) as a dominant r-process source and the star formation efficiency of $\\sim 10^{-10} \\hbox{yr}^{-1}$. For neutron star mergers as an r-process source, their coalescence timescale has to be $ \\sim 10^7$yrs, and the event rates $...

  2. Onboard hierarchical network

    Science.gov (United States)

    Tunesi, Luca; Armbruster, Philippe

    2004-02-01

    The objective of this paper is to demonstrate a suitable hierarchical networking solution to improve capabilities and performances of space systems, with significant recurrent costs saving and more efficient design & manufacturing flows. Classically, a satellite can be split in two functional sub-systems: the platform and the payload complement. The platform is in charge of providing power, attitude & orbit control and up/down-link services, whereas the payload represents the scientific and/or operational instruments/transponders and embodies the objectives of the mission. One major possibility to improve the performance of payloads, by limiting the data return to pertinent information, is to process data on board thanks to a proper implementation of the payload data system. In this way, it is possible to share non-recurring development costs by exploiting a system that can be adopted by the majority of space missions. It is believed that the Modular and Scalable Payload Data System, under development by ESA, provides a suitable solution to fulfil a large range of future mission requirements. The backbone of the system is the standardised high data rate SpaceWire network http://www.ecss.nl/. As complement, a lower speed command and control bus connecting peripherals is required. For instance, at instrument level, there is a need for a "local" low complexity bus, which gives the possibility to command and control sensors and actuators. Moreover, most of the connections at sub-system level are related to discrete signals management or simple telemetry acquisitions, which can easily and efficiently be handled by a local bus. An on-board hierarchical network can therefore be defined by interconnecting high-speed links and local buses. Additionally, it is worth stressing another important aspect of the design process: Agencies and ESA in particular are frequently confronted with a big consortium of geographically spread companies located in different countries, each one

  3. Direct hierarchical assembly of nanoparticles

    Science.gov (United States)

    Xu, Ting; Zhao, Yue; Thorkelsson, Kari

    2014-07-22

    The present invention provides hierarchical assemblies of a block copolymer, a bifunctional linking compound and a nanoparticle. The block copolymers form one micro-domain and the nanoparticles another micro-domain.

  4. Hierarchical community structure in complex (social) networks

    CERN Document Server

    Massaro, Emanuele

    2014-01-01

    The investigation of community structure in networks is a task of great importance in many disciplines, namely physics, sociology, biology and computer science where systems are often represented as graphs. One of the challenges is to find local communities from a local viewpoint in a graph without global information in order to reproduce the subjective hierarchical vision for each vertex. In this paper we present the improvement of an information dynamics algorithm in which the label propagation of nodes is based on the Markovian flow of information in the network under cognitive-inspired constraints \\cite{Massaro2012}. In this framework we have introduced two more complex heuristics that allow the algorithm to detect the multi-resolution hierarchical community structure of networks from a source vertex or communities adopting fixed values of model's parameters. Experimental results show that the proposed methods are efficient and well-behaved in both real-world and synthetic networks.

  5. Hierarchical curiosity loops and active sensing.

    Science.gov (United States)

    Gordon, Goren; Ahissar, Ehud

    2012-08-01

    A curious agent acts so as to optimize its learning about itself and its environment, without external supervision. We present a model of hierarchical curiosity loops for such an autonomous active learning agent, whereby each loop selects the optimal action that maximizes the agent's learning of sensory-motor correlations. The model is based on rewarding the learner's prediction errors in an actor-critic reinforcement learning (RL) paradigm. Hierarchy is achieved by utilizing previously learned motor-sensory mapping, which enables the learning of other mappings, thus increasing the extent and diversity of knowledge and skills. We demonstrate the relevance of this architecture to active sensing using the well-studied vibrissae (whiskers) system, where rodents acquire sensory information by virtue of repeated whisker movements. We show that hierarchical curiosity loops starting from optimally learning the internal models of whisker motion and then extending to object localization result in free-air whisking and object palpation, respectively. PMID:22386787

  6. Semantic Image Segmentation with Contextual Hierarchical Models.

    Science.gov (United States)

    Seyedhosseini, Mojtaba; Tasdizen, Tolga

    2016-05-01

    Semantic segmentation is the problem of assigning an object label to each pixel. It unifies the image segmentation and object recognition problems. The importance of using contextual information in semantic segmentation frameworks has been widely realized in the field. We propose a contextual framework, called contextual hierarchical model (CHM), which learns contextual information in a hierarchical framework for semantic segmentation. At each level of the hierarchy, a classifier is trained based on downsampled input images and outputs of previous levels. Our model then incorporates the resulting multi-resolution contextual information into a classifier to segment the input image at original resolution. This training strategy allows for optimization of a joint posterior probability at multiple resolutions through the hierarchy. Contextual hierarchical model is purely based on the input image patches and does not make use of any fragments or shape examples. Hence, it is applicable to a variety of problems such as object segmentation and edge detection. We demonstrate that CHM performs at par with state-of-the-art on Stanford background and Weizmann horse datasets. It also outperforms state-of-the-art edge detection methods on NYU depth dataset and achieves state-of-the-art on Berkeley segmentation dataset (BSDS 500). PMID:26336116

  7. A New Metrics for Hierarchical Clustering

    Institute of Scientific and Technical Information of China (English)

    YANGGuangwen; SHIShuming; WANGDingxing

    2003-01-01

    Hierarchical clustering is a popular method of performing unsupervised learning. Some metric must be used to determine the similarity between pairs of clusters in hierarchical clustering. Traditional similarity metrics either can deal with simple shapes (i.e. spherical shapes) only or are very sensitive to outliers (the chaining effect). The main contribution of this paper is to propose some potential-based similarity metrics (APES and AMAPES) between clusters in hierarchical clustering, inspired by the concepts of the electric potential and the gravitational potential in electromagnetics and astronomy. The main features of these metrics are: the first, they have strong antijamming capability; the second, they are capable of finding clusters of different shapes such as spherical, spiral, chain, circle, sigmoid, U shape or other complex irregular shapes; the third, existing algorithms and research fruits for classical metrics can be adopted to deal with these new potential-based metrics with no or little modification. Experiments showed that the new metrics are more superior to traditional ones. Different potential functions are compared, and the sensitivity to parameters is also analyzed in this paper.

  8. Fast, Linear Time Hierarchical Clustering using the Baire Metric

    CERN Document Server

    Contreras, Pedro

    2011-01-01

    The Baire metric induces an ultrametric on a dataset and is of linear computational complexity, contrasted with the standard quadratic time agglomerative hierarchical clustering algorithm. In this work we evaluate empirically this new approach to hierarchical clustering. We compare hierarchical clustering based on the Baire metric with (i) agglomerative hierarchical clustering, in terms of algorithm properties; (ii) generalized ultrametrics, in terms of definition; and (iii) fast clustering through k-means partititioning, in terms of quality of results. For the latter, we carry out an in depth astronomical study. We apply the Baire distance to spectrometric and photometric redshifts from the Sloan Digital Sky Survey using, in this work, about half a million astronomical objects. We want to know how well the (more costly to determine) spectrometric redshifts can predict the (more easily obtained) photometric redshifts, i.e. we seek to regress the spectrometric on the photometric redshifts, and we use clusterwi...

  9. The new model of chemical evolution of r-process elements based on the hierarchical galaxy formation. I. Ba and Eu

    International Nuclear Information System (INIS)

    We investigate the chemical enrichment of r-process elements in the early evolutionary stages of the Milky Way halo within the framework of hierarchical galaxy formation using a semi-analytic merger tree. In this paper, we focus on heavy r-process elements, Ba and Eu, of extremely metal-poor (EMP) stars and give constraints on their astronomical sites. Our models take into account changes of the surface abundances of EMP stars by the accretion of interstellar medium (ISM). We also consider metal-enrichment of intergalactic medium by galactic winds and the resultant pre-enrichment of proto-galaxies. The trend and scatter of the observed r-process abundances are well reproduced by our hierarchical model with ∼10% of core-collapse supernovae in low-mass end (∼10 M ☉) as a dominant r-process source and the star formation efficiency of ∼10–10 yr–1. For neutron star mergers as an r-process source, their coalescence timescale has to be ∼107 yr, and the event rates ∼100 times larger than currently observed in the Galaxy. We find that the accretion of ISM is a dominant source of r-process elements for stars with [Ba/H] < –3.5. In this model, a majority of stars at [Fe/H] < –3 are formed without r-process elements, but their surfaces are polluted by the ISM accretion. The pre-enrichment affects ∼4% of proto-galaxies, and yet, is surpassed by the ISM accretion in the surface of EMP stars.

  10. Universal hierarchical behavior of citation networks

    International Nuclear Information System (INIS)

    Many of the essential features of the evolution of scientific research are imprinted in the structure of citation networks. Connections in these networks imply information about the transfer of knowledge among papers, or, in other words, edges describe the impact of papers on other publications. This inherent meaning of the edges implies that citation networks can exhibit hierarchical features that are typical of networks based on decision making. In this paper, we investigate the hierarchical structure of citation networks consisting of papers in the same field. We find that the majority of the networks follow a universal trend towards a highly hierarchical state, and the various fields display differences only concerning (i) their phase in life (distance from the ‘birth’ of a field) or (ii) the characteristic time according to which they are approaching the stationary state. We also show by a simple argument that the alterations in the behavior are related to and can be understood by the degree of specialization corresponding to the fields. Our results suggest that during the accumulation of knowledge in a given field, some papers are gradually becoming relatively more influential than most other papers. (paper)

  11. Micromechanical design of hierarchical composites using global load sharing theory

    Science.gov (United States)

    Rajan, V. P.; Curtin, W. A.

    2016-05-01

    Hierarchical composites, embodied by natural materials ranging from bone to bamboo, may offer combinations of material properties inaccessible to conventional composites. Using global load sharing (GLS) theory, a well-established micromechanics model for composites, we develop accurate numerical and analytical predictions for the strength and toughness of hierarchical composites with arbitrary fiber geometries, fiber strengths, interface properties, and number of hierarchical levels, N. The model demonstrates that two key material properties at each hierarchical level-a characteristic strength and a characteristic fiber length-control the scalings of composite properties. One crucial finding is that short- and long-fiber composites behave radically differently. Long-fiber composites are significantly stronger than short-fiber composites, by a factor of 2N or more; they are also significantly tougher because their fiber breaks are bridged by smaller-scale fibers that dissipate additional energy. Indeed, an "infinite" fiber length appears to be optimal in hierarchical composites. However, at the highest level of the composite, long fibers localize on planes of pre-existing damage, and thus short fibers must be employed instead to achieve notch sensitivity and damage tolerance. We conclude by providing simple guidelines for microstructural design of hierarchical composites, including the selection of N, the fiber lengths, the ratio of length scales at successive hierarchical levels, the fiber volume fractions, and the desired properties of the smallest-scale reinforcement. Our model enables superior hierarchical composites to be designed in a rational way, without resorting either to numerical simulation or trial-and-error-based experimentation.

  12. Technique for fast and efficient hierarchical clustering

    Science.gov (United States)

    Stork, Christopher

    2013-10-08

    A fast and efficient technique for hierarchical clustering of samples in a dataset includes compressing the dataset to reduce a number of variables within each of the samples of the dataset. A nearest neighbor matrix is generated to identify nearest neighbor pairs between the samples based on differences between the variables of the samples. The samples are arranged into a hierarchy that groups the samples based on the nearest neighbor matrix. The hierarchy is rendered to a display to graphically illustrate similarities or differences between the samples.

  13. A hierarchical architecture to multiple target tracking

    OpenAIRE

    Rowe, Daniel; Huerta, Iván; Pedersoli, Marco; Guinea, Soledad; Gonzàlez, Jordi; Villanueva, Juan J.

    2007-01-01

    This work presents an architecture based on a modular and hierarchically-organised system to perform Multiple-Target Tracking (MTT). A set of co-operating modules, which work following both bottom-up and top-down paradigms, are distributed through three levels. Each level is devoted to a main task: Target Detection, Low-Level Tracking (LLT), and High-Level Tracking (HLT). A principled event management is embedded in the system. The system is allowed to switch among Motion-based Tracking (MBT)...

  14. Hierarchical Dragonfly Wing: Microstructure-Biomechanical Behavior Relations

    Institute of Scientific and Technical Information of China (English)

    Yinglong Chen; Xishu Wang; Huaihui Ren; Hang Yin; Su Jia

    2012-01-01

    The dragonfly wing,which consists of veins and membrane,is of biological hierarchical material.We observed the cross-sections of longitudinal veins and membrane using Environmental Scanning Electron Microscopy (ESEM).Based on the experiments and previous studies,we described the longitudinal vein and the membrane in terms of two hierarchical levels of organization of composite materials at the micro- and nano-scales.The longitudinal vein of dragonfly wing has a complex sandwich structure with two chitinous shells and a protein layer,and it is considered as the first hierarchical level of the vein.Moreover,the chitinous shells are concentric multilayered structures.Clusters of nano-fibrils grow along the circumferential orientation embedded into the protein layer.It is considered as the second level of the hierarchy.Similarly,the upper and lower epidermises of membrane constitute the first hierarchical level of organization in micro scale.Similar to the vein shell,the membrane epidermises were found to be a paralleled multilayered structure,defined as the second hierarchical level of the membrane.Combining with the mechanical behavior analysis of the dragonfly wing,we concluded that the growth orientation of the hierarchical structure of the longitudinal vein and membrane is relevant to its biomechanical behavior.

  15. Urban pattern: Layout design by hierarchical domain splitting

    KAUST Repository

    Yang, Yongliang

    2013-11-01

    We present a framework for generating street networks and parcel layouts. Our goal is the generation of high-quality layouts that can be used for urban planning and virtual environments. We propose a solution based on hierarchical domain splitting using two splitting types: streamline-based splitting, which splits a region along one or multiple streamlines of a cross field, and template-based splitting, which warps pre-designed templates to a region and uses the interior geometry of the template as the splitting lines. We combine these two splitting approaches into a hierarchical framework, providing automatic and interactive tools to explore the design space.

  16. Construction of Amperometric Glucose Biosensor based onIn-situ Fabricated Hierarchical Meso-macroporous SiO2 Modiifed AuFilm Electrodes

    Institute of Scientific and Technical Information of China (English)

    TANG Min; LIN Xinhua; LI Maoguo; LI Jie; NI Lin; YIN Shiping

    2016-01-01

    Gold nanoparticles (GNPs) modified hierarchical meso-macroporous (HMMP) SiO2 layer on the surface of Au iflm electrode was developed as a novel enzyme immobilization matrix for biosensors construction. HMMP SiO2-Au bilayer film electrodes were in-situ fabricated with magnetron sputtering process and templating method. The as-prepared HMMP SiO2 films were characterized by SEM, TEM, and cyclic voltammetry (CV). The modiifed layer of HMMP SiO2 has interconnected pore channels, and the sizes of macropores and mesopores are about 330 nm and 9 nm, respectively. The HMMP SiO2 modiifed gold iflm electrodes not only have no diffusion barrier for electrochemical probes, but also exhibit good electrochemical properties. In addition, the activity and stability of the immobilized enzyme can be commendably retained in HMMP SiO2. The biosensor exhibits an excellent bioelectrocatalytic response to glucose with a linear range of 1.0×10-4 M-1.0×10-2 M, high sensitivity of 18.0 μA·mM-1·cm-2, as well as good reproducibility and stability.

  17. CdS/CdSe Co-sensitized Solar Cells Based on Hierarchically Structured SnO2/TiO2 Hybrid Films.

    Science.gov (United States)

    Chen, Zeng; Wei, Chaochao; Li, Shengjun; Diao, Chunli; Li, Wei; Kong, Wenping; Zhang, Zhenlong; Zhang, Weifeng

    2016-12-01

    SnO2 nanosheet-structured films were prepared on a fluorine-doped tin oxide (FTO) substrate using ZnO nanosheet as template. The as-prepared SnO2 nanosheets contained plenty of nano-voids and were generally vertical to the substrate. TiO2 nanoparticles were homogeneously deposited into the intervals between the SnO2 nanosheets to prepare a hierarchically structured SnO2/TiO2 hybrid film. The hybrid films were co-sensitized with CdS and CdSe quantum dots. The sensitized solar cells assembled with the SnO2/TiO2 hybrid film showed much higher photoelectricity conversion efficiency than the cells assembled with pure TiO2 films. The lifetime of photoinduced electron was also investigated through electrochemical impedance spectroscopy, which showed that the SnO2/TiO2 hybrid film electrode is as long as the TiO2 film electrode. PMID:27299650

  18. CdS/CdSe Co-sensitized Solar Cells Based on Hierarchically Structured SnO2/TiO2 Hybrid Films

    Science.gov (United States)

    Chen, Zeng; Wei, Chaochao; Li, Shengjun; Diao, Chunli; Li, Wei; Kong, Wenping; Zhang, Zhenlong; Zhang, Weifeng

    2016-06-01

    SnO2 nanosheet-structured films were prepared on a fluorine-doped tin oxide (FTO) substrate using ZnO nanosheet as template. The as-prepared SnO2 nanosheets contained plenty of nano-voids and were generally vertical to the substrate. TiO2 nanoparticles were homogeneously deposited into the intervals between the SnO2 nanosheets to prepare a hierarchically structured SnO2/TiO2 hybrid film. The hybrid films were co-sensitized with CdS and CdSe quantum dots. The sensitized solar cells assembled with the SnO2/TiO2 hybrid film showed much higher photoelectricity conversion efficiency than the cells assembled with pure TiO2 films. The lifetime of photoinduced electron was also investigated through electrochemical impedance spectroscopy, which showed that the SnO2/TiO2 hybrid film electrode is as long as the TiO2 film electrode.

  19. Disposable all-solid-state pH and glucose sensors based on conductive polymer covered hierarchical AuZn oxide.

    Science.gov (United States)

    Kim, Dong-Min; Cho, Seong Je; Cho, Chul-Ho; Kim, Kwang Bok; Kim, Min-Yeong; Shim, Yoon-Bo

    2016-05-15

    Poly(terthiophene benzoic acid) (pTBA) layered-AuZn alloy oxide (AuZnOx) deposited on the screen printed carbon electrode (pTBA/AuZnOx/SPCE) was prepared to create a disposable all-solid-state pH sensor at first. Further, FAD-glucose oxidase (GOx) was immobilized onto the pTBA/AuZnOx/SPCE to fabricate a glucose sensor. The characterizations of the sensor probe reveal that AuZnOx forms a homogeneous hierarchical structure, and that the polymerized pTBA layer on the alloy oxide surface captures GOx covalently. The benzoic acid group of pTBA coated on the probe layer synergetically improved the pH response of the alloy oxide and provide chemical binding sites to enzyme, which resulted in a Nernstian behavior (59.2 ± 0.5 mV/pH) in the pH range of 2-13. The experimental parameters affecting the glucose analysis were studied in terms of pH, temperature, humidity, and interferences. The sensor exhibited a fast response time <1s and a dynamic range between 30 and 500 mg/dL glucose with a detection limit of 17.23 ± 0.32 mg/dL. The reliabilities of the disposable pH and glucose sensors were examined for biological samples. PMID:26703994

  20. Parallel Computation for the Finite Element Method Based on a Hierarchical Data Structure%基于层次化数据结构的并行有限元计算

    Institute of Scientific and Technical Information of China (English)

    赵伟波; 刘青凯; 秦桂明

    2012-01-01

    高效数据结构及并行算法是大规模并行有限元计算的关键.本文面向非结构网格,提出了一种层次化的数据结构,并在该数据结构基础上设计了并行有限元算法.最后,用数值算例验证了数据结构和并行算法的正确性和并行可扩展性.%Effective data structures and parallel algorithms play key roles in large scale parallel computation of FEM(finite element method). This paper proposes a hierarchical data structure for the unstructured mesh. Based on this structure,we design algorithms for the parallel computation of FEM. Numerical results have been presented to show the validity and scalability of the data structure and algorithms.

  1. Hierarchical processing in the prefrontal cortex in a variety of cognitive domains

    Directory of Open Access Journals (Sweden)

    Hyeon-Ae eJeon

    2014-11-01

    Full Text Available This review scrutinizes several findings on human hierarchical processing within the prefrontal cortex (PFC in diverse cognitive domains. Converging evidence from previous studies has shown that the PFC, specifically Brodmann area (BA 44, may function as the essential region for hierarchical processing across the domains. In language fMRI studies, BA 44 was significantly activated for the hierarchical processing of center-embedded sentences and this pattern of activations was also observed in artificial grammar. The same pattern was observed in the visuo-spatial domain where BA44 was actively involved in the processing of hierarchy for the visual symbol. Musical syntax, which is the rule-based arrangement of musical sets, has also been construed as hierarchical processing as in the language domain such that the activation in BA44 was observed in a chord sequence paradigm. P600 ERP was also engendered during the processing of musical hierarchy. Along with a longstanding idea that a human’s number faculty is developed as a by-product of language faculty, BA44 was closely involved in hierarchical processing in mental arithmetic. This review extended its discussion of hierarchical processing to hierarchical behavior, that is, human action which has been referred to as being hierarchically composed. Several lesion and TMS studies supported the involvement of BA44 for hierarchical processing in the action domain. Lastly, the hierarchical organization of cognitive controls was discussed within the PFC, forming a cascade of top-down hierarchical processes operating along a posterior-to-anterior axis of the lateral PFC including BA44 within the network. It is proposed that PFC is actively involved in different forms of hierarchical processing and specifically BA44 may play an integral role in the process. Taking levels of proficiency and subcortical areas into consideration may provide further insight into the functional role of BA44 for hierarchical

  2. An effective immunization strategy for airborne epidemics in modular and hierarchical social contact network

    Science.gov (United States)

    Song, Zhichao; Ge, Yuanzheng; Luo, Lei; Duan, Hong; Qiu, Xiaogang

    2015-12-01

    Social contact between individuals is the chief factor for airborne epidemic transmission among the crowd. Social contact networks, which describe the contact relationships among individuals, always exhibit overlapping qualities of communities, hierarchical structure and spatial-correlated. We find that traditional global targeted immunization strategy would lose its superiority in controlling the epidemic propagation in the social contact networks with modular and hierarchical structure. Therefore, we propose a hierarchical targeted immunization strategy to settle this problem. In this novel strategy, importance of the hierarchical structure is considered. Transmission control experiments of influenza H1N1 are carried out based on a modular and hierarchical network model. Results obtained indicate that hierarchical structure of the network is more critical than the degrees of the immunized targets and the modular network layer is the most important for the epidemic propagation control. Finally, the efficacy and stability of this novel immunization strategy have been validated as well.

  3. Modelling complex networks by random hierarchical graphs

    Directory of Open Access Journals (Sweden)

    M.Wróbel

    2008-06-01

    Full Text Available Numerous complex networks contain special patterns, called network motifs. These are specific subgraphs, which occur oftener than in randomized networks of Erdős-Rényi type. We choose one of them, the triangle, and build a family of random hierarchical graphs, being Sierpiński gasket-based graphs with random "decorations". We calculate the important characteristics of these graphs - average degree, average shortest path length, small-world graph family characteristics. They depend on probability of decorations. We analyze the Ising model on our graphs and describe its critical properties using a renormalization-group technique.

  4. Hierarchical task analysis: Developments, applications and extensions

    OpenAIRE

    Stanton, Neville A.

    2006-01-01

    Hierarchical task analysis (HTA) is a core ergonomics approach with a pedigree of over 30 years continuous use. At its heart, HTA is based upon a theory of performance and has only three governing principles. Originally developed as a means of determining training requirements, there was no way the initial pioneers of HTA could have foreseen the extent of its success. HTA has endured as a way of representing a system sub-goal hierarchy for extended analysis. It has been used for a range of ap...

  5. Chemical evolution in hierarchical scenarios

    OpenAIRE

    Tissera P.B.

    2012-01-01

    We studied the chemical properties of Milky-Way mass galaxies. We found common global chemical patterns with particularities which reflect their different assembly histories in a hierarchical scenario. We carried out a comprehensively analysis of the dynamical components (central spheroid, disc, inner and outer haloes) and their chemical properties.

  6. Hierarchical Microaggressions in Higher Education

    Science.gov (United States)

    Young, Kathryn; Anderson, Myron; Stewart, Saran

    2015-01-01

    Although there has been substantial research examining the effects of microaggressions in the public sphere, there has been little research that examines microaggressions in the workplace. This study explores the types of microaggressions that affect employees at universities. We coin the term "hierarchical microaggression" to represent…

  7. Hierarchical classification of social groups

    OpenAIRE

    Витковская, Мария

    2001-01-01

    Classification problems are important for every science, and for sociology as well. Social phenomena, examined from the aspect of classification of social groups, can be examined deeper. At present one common classification of groups does not exist. This article offers the hierarchical classification of social group.

  8. Analytical Evaluation of Hierarchical Planning Systems

    OpenAIRE

    Dempster, M.A.H.; Fisher, M.L.; Jansen, L; Lageweg, B.J.; J. K. Lenstra; Rinnooy Kan, A.H.G.

    1984-01-01

    Hierarchical planning systems have become popular for multilevel decision problems. After reviewing the concept of hierarchical planning and citing some examples, the authors describe a method for analytic evaluation of a hierarchical planning system. They show that multilevel decision problems can be nicely modeled as multistage stochastic programs. Then any hierarchical planning system can be measured against the yardstick of optimality in this stochastic program. They demonstrate this ap...

  9. Hierarchical moving curved fitting filtering method based on LIDAR data%多级移动曲面拟合LIDAR数据滤波算法

    Institute of Scientific and Technical Information of China (English)

    苏伟; 孙中平; 赵冬玲; 孙崇利; 张超; 杨建宇

    2009-01-01

    LIDAR data is accurate 3D data of terrain acquired from airborne laser detection and ranging system. Compared with hardware technique, data post-processing technique of LIDAR data is weak and time consumed. In this situation, a HMCFA (Hierarchical Moving Curved Fitting Algorithm) filtering method of LIDAR data is reported in this paper. Firstly, block grid searching and indexing mechanism is set up to label discrete LIDAR cloud points. Secondly, quadratic polynomial is set up to fit land terrain with different window size. At last, adaptive threshold is used to distinguish ground points and non-ground points. Accuracy assessment results indicate that the filter error is less than lm, which can be used in application.%为提高城市区LIDAR数据滤波精度,提出了一种多级移动曲面拟合滤波方法.建立区块网格搜寻及索引机制完成对离散LIDAR点云的标示;通过建立二次多项式完成参考曲面的拟合,不同窗口大小获得不同层次的拟合曲面;设置自适应阈值,完成地面点与非地面点的判断.精度评价结果表明,该滤波算法误差在1m以内,能够满足实际应用的需求.

  10. Solvothermal Synthesis of Three-Dimensional Hierarchical CuS Microspheres from a Cu-Based Ionic Liquid Precursor for High-Performance Asymmetric Supercapacitors.

    Science.gov (United States)

    Zhang, Jing; Feng, Huijie; Yang, Jiaqin; Qin, Qing; Fan, Hongmin; Wei, Caiying; Zheng, Wenjun

    2015-10-01

    It is meaningful to exploit copper sulfide materials with desired structure as well as potential application due to their cheapness and low toxicity. A low-temperature and facile solvothermal method for preparing three-dimensional (3D) hierarchical covellite (CuS) microspheres from an ionic liquid precursor [Bmim]2Cu2Cl6 (Bmim = 1-butyl-3-methylimidazolium) is reported. The formation of CuS nanostructures was achieved by decomposition of intermediate complex Cu(Tu)3Cl (thiourea = Tu), which produced CuS microspheres with diameters of 2.5-4 μm assembled by nanosheets with thicknesses of 10-15 nm. The ionic liquid, as an "all-in-one" medium, played a key role for the fabrication and self-assembly of CuS nanosheets. The alkylimidazolium rings ([Bmim](+)) were found to adsorb onto the (001) facets of CuS crystals, which inhibited the crystal growth along the [001] direction, while the alkyl chain had influence on the assembly of CuS nanosheets. The CuS microspheres showed enhanced electrochemical performance and high stability for the application in supercapacitors due to intriguing structural design and large specific surface area. When this well-defined CuS electrode was assembled into an asymmetric supercapacitor (ASC) with an activated carbon (AC) electrode, the CuS//AC-ASC demonstrated good cycle performance (∼88% capacitance after 4000 cycles) and high energy density (15.06 W h kg(-1) at a power density of 392.9 W kg(-1)). This work provides new insights into the use of copper sulfide electrode materials for asymmetric supercapacitors and other electrochemical devices. PMID:26371955

  11. Image Information Mining Utilizing Hierarchical Segmentation

    Science.gov (United States)

    Tilton, James C.; Marchisio, Giovanni; Koperski, Krzysztof; Datcu, Mihai

    2002-01-01

    The Hierarchical Segmentation (HSEG) algorithm is an approach for producing high quality, hierarchically related image segmentations. The VisiMine image information mining system utilizes clustering and segmentation algorithms for reducing visual information in multispectral images to a manageable size. The project discussed herein seeks to enhance the VisiMine system through incorporating hierarchical segmentations from HSEG into the VisiMine system.

  12. 基于分层策略的翼型多参量气动优化设计研究%Research on Multi- parameters Aerodynamic Shape Optimization Design of Airfoil Based on Hierarchical Starategy

    Institute of Scientific and Technical Information of China (English)

    李鸿岩; 董军

    2012-01-01

    与基于梯度的优化方法相比,遗传算法因其极强的鲁棒性、随机搜索及优化结果全局性等特点在工程优化中得到越来越广泛的应用.为提高优化设计的效率,改进了传统的遗传算法,采用并行分层策略基因遗传算法开展了翼型多参量气动优化设计研究,包括翼型和多段翼型的基因编码、外形参数化,以及动网格技术.结果表明,并行分层策略在得到较优气动优化结果的同时,极大地缩短了优化时间,提高了计算效率,具有广阔的工程应用前景.%Compared with the optimization method based on the gradient theory, genetic algorithm (GA) is more and more widely applied in the field of engineer optimization due to its robustness, randomicity and global optimal performance. In order to improve the efficiency of the optimization design,the traditional GA for multi- parameters aerodynamic shape optimum design of airfoil and multi- element airfoil is improved by using hierarchical parallelization strategy. Genetic coding and shape parameterization are investigated in this paper in combination with mesh moving technical. The results show that hierarchical starat-egy that can dramatically shorten the time for optimization and improve the computational efficiency is efficient and reasonable. So,this method has wide prospects for engineering applications.

  13. Hierarchical Proteinosomes for Programmed Release of Multiple Components.

    Science.gov (United States)

    Liu, Xiaoman; Zhou, Pei; Huang, Yudong; Li, Mei; Huang, Xin; Mann, Stephen

    2016-06-13

    A facile route to hierarchically organized multicompartmentalized proteinosomes based on a recursive Pickering emulsion procedure using amphiphilic protein-polymer nanoconjugate building blocks is described. The number of incarcerated guest proteinosomes within a single host proteinosome is controlled, and enzymes and genetic polymers encapsulated within targeted subcompartments to produce chemically organized multi-tiered structures. Three types of spatiotemporal response-retarded concomitant release, synchronous release or hierarchical release of dextran and DNA-are demonstrated based on the sequential response of the host and guest membranes to attack by protease, or through variations in the positioning of disulfide-containing cross-links in either the host or guest proteinosomes integrated into the nested architectures. Overall, our studies provide a step towards the construction of hierarchically structured synthetic protocells with chemically and spatially integrated proto-organelles. PMID:27144816

  14. Unmanned Aerial Vehicle Path Planning Based on Hierarchical Thinking%基于分层思想的无人飞行器航路规划研究

    Institute of Scientific and Technical Information of China (English)

    刘福; 张殿富; 秦军波

    2013-01-01

    在无人飞行器航路规划问题的研究中,为提高航路规划的效率和精度,针对传统遗传算法收敛速度慢、易陷入局部最优、寻优精度较差的问题,提出了一种分层思想的解决方法.首先用链接图法描述规划环境,通过采用Dijkstra算法寻找初始最优航路,并利用航路编码技术对初始航路进行优化;然后在已有的研究成果上,提出一种集混沌优化、模拟退火、遗传算法为一体的改进遗传算法(CGASA),在解决多目标多约束优化问题时取得了较好的结果;最后综合考虑飞行器的机动性能、威胁因素、飞越目标进入角度等代价的选取,利用改进遗传算法调整导航点的位置得出了满足性能要求的航路.%In the research on route planning of uaraanned aerial vechicle,the basic algorithm may always have problelms such as falling in local optimum,slow convergence speed leading to low efficiency.In this paper,the hierarchical thinking was considered in unmanned aerial vehicle route planning.Firstly,the planning environment was described with link graph,and Dijkstra algorithm was used to find the initial optimal route; then on the findings of other researchers,an improved genetic algorithm(CGASA) was advocated; at last,considering the selection costs of the motor perfonnance of the aircraft,threats,attacks entry angle and so on,the improved genetic algorithm was used to adjust the waypoint location to come to meet the performance requirements of the path.

  15. Hierarchical Parallelization of Gene Differential Association Analysis

    Directory of Open Access Journals (Sweden)

    Dwarkadas Sandhya

    2011-09-01

    Full Text Available Abstract Background Microarray gene differential expression analysis is a widely used technique that deals with high dimensional data and is computationally intensive for permutation-based procedures. Microarray gene differential association analysis is even more computationally demanding and must take advantage of multicore computing technology, which is the driving force behind increasing compute power in recent years. In this paper, we present a two-layer hierarchical parallel implementation of gene differential association analysis. It takes advantage of both fine- and coarse-grain (with granularity defined by the frequency of communication parallelism in order to effectively leverage the non-uniform nature of parallel processing available in the cutting-edge systems of today. Results Our results show that this hierarchical strategy matches data sharing behavior to the properties of the underlying hardware, thereby reducing the memory and bandwidth needs of the application. The resulting improved efficiency reduces computation time and allows the gene differential association analysis code to scale its execution with the number of processors. The code and biological data used in this study are downloadable from http://www.urmc.rochester.edu/biostat/people/faculty/hu.cfm. Conclusions The performance sweet spot occurs when using a number of threads per MPI process that allows the working sets of the corresponding MPI processes running on the multicore to fit within the machine cache. Hence, we suggest that practitioners follow this principle in selecting the appropriate number of MPI processes and threads within each MPI process for their cluster configurations. We believe that the principles of this hierarchical approach to parallelization can be utilized in the parallelization of other computationally demanding kernels.

  16. A hierarchical method for discrete structural topology design problems with local stress and displacement constraints

    DEFF Research Database (Denmark)

    Stolpe, Mathias; Stidsen, Thomas K.

    2007-01-01

    In this paper, we present a hierarchical optimization method for finding feasible true 0-1 solutions to finite-element-based topology design problems. The topology design problems are initially modelled as non-convex mixed 0-1 programs. The hierarchical optimization method is applied to the problem...

  17. Oracle Database DBFS Hierarchical Storage Overview

    International Nuclear Information System (INIS)

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory creates large numbers of images during each shot cycle for the analysis of optics, target inspection and target diagnostics. These images must be readily accessible once they are created and available for the 30 year lifetime of the facility. The Livermore Computing Center (LC) runs a High Performance Storage System (HPSS) that is capable of storing NIF's estimated 1 petabyte of diagnostic images at a fraction of what it would cost NIF to operate its own automated tape library. With Oracle 11g Release 2 database, it is now possible to create an application transparent, hierarchical storage system using the LC's HPSS. Using the Oracle DBMS-LOB and DBMS-DBFS-HS packages a SecureFile LOB can now be archived to storage outside of the database and accessed seamlessly through a DBFS 'link'. NIF has chosen to use this technology to implement a hierarchical store for its image based SecureFile LOBs. Using a modified external store and DBFS links, files are written to and read from a disk 'staging area' using Oracle's backup utility. Database external procedure calls invoke OS based scripts to manage a staging area and the transfer of the backup files between the staging area and the Lab's HPSS.

  18. Multiple Comparisons in Genetic Association Studies: A Hierarchical Modeling Approach

    Science.gov (United States)

    Yi, Nengjun; Xu, Shizhong; Lou, Xiang-Yang; Mallick, Himel

    2016-01-01

    Multiple comparisons or multiple testing has been viewed as a thorny issue in genetic association studies aiming to detect disease-associated genetic variants from a large number of genotyped variants. We alleviate the problem of multiple comparisons by proposing a hierarchical modeling approach that is fundamentally different from the existing methods. The proposed hierarchical models simultaneously fit as many variables as possible and shrink unimportant effects towards zero. Thus, the hierarchical models yield more efficient estimates of parameters than the traditional methods that analyze genetic variants separately, and also coherently address the multiple comparisons problem due to largely reducing the effective number of genetic effects and the number of statistically ‘significant’ effects. We develop a method for computing the effective number of genetic effects in hierarchical generalized linear models, and propose a new adjustment for multiple comparisons, the hierarchical Bonferroni correction, based on the effective number of genetic effects. Our approach not only increases the power to detect disease-associated variants but also controls the Type I error. We illustrate and evaluate our method with real and simulated data sets from genetic association studies. The method has been implemented in our freely available R package BhGLM (http://www.ssg.uab.edu/bhglm/). PMID:24259248

  19. Hierarchical fringe tracking

    OpenAIRE

    Petrov, Romain G.; Elhalkouj, Thami; Boskri, Abdelkarim; Folcher, Jean-Pierre; Lagarde, Stephane; Bresson, Yves; Benkhaldoum, Zouhair; Lazrek, Mohamed; Rakshit, Suvendu

    2014-01-01

    The limiting magnitude is a key issue for optical interferometry. Pairwise fringe trackers based on the integrated optics concepts used for example in GRAVITY seem limited to about K=10.5 with the 8m Unit Telescopes of the VLTI, and there is a general "common sense" statement that the efficiency of fringe tracking, and hence the sensitivity of optical interferometry, must decrease as the number of apertures increases, at least in the near infrared where we are still limited by detector readou...

  20. Anti-hierarchical evolution of the active galactic nucleus space density in a hierarchical universe

    Energy Technology Data Exchange (ETDEWEB)

    Enoki, Motohiro [Faculty of Business Administration, Tokyo Keizai University, Kokubunji, Tokyo 185-8502 (Japan); Ishiyama, Tomoaki [Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Kobayashi, Masakazu A. R. [Research Center for Space and Cosmic Evolution, Ehime University, Matsuyama, Ehime 790-8577 (Japan); Nagashima, Masahiro, E-mail: enokimt@tku.ac.jp [Faculty of Education, Nagasaki University, Nagasaki, Nagasaki 852-8521 (Japan)

    2014-10-10

    Recent observations show that the space density of luminous active galactic nuclei (AGNs) peaks at higher redshifts than that of faint AGNs. This downsizing trend in the AGN evolution seems to be contradictory to the hierarchical structure formation scenario. In this study, we present the AGN space density evolution predicted by a semi-analytic model of galaxy and AGN formation based on the hierarchical structure formation scenario. We demonstrate that our model can reproduce the downsizing trend of the AGN space density evolution. The reason for the downsizing trend in our model is a combination of the cold gas depletion as a consequence of star formation, the gas cooling suppression in massive halos, and the AGN lifetime scaling with the dynamical timescale. We assume that a major merger of galaxies causes a starburst, spheroid formation, and cold gas accretion onto a supermassive black hole (SMBH). We also assume that this cold gas accretion triggers AGN activity. Since the cold gas is mainly depleted by star formation and gas cooling is suppressed in massive dark halos, the amount of cold gas accreted onto SMBHs decreases with cosmic time. Moreover, AGN lifetime increases with cosmic time. Thus, at low redshifts, major mergers do not always lead to luminous AGNs. Because the luminosity of AGNs is correlated with the mass of accreted gas onto SMBHs, the space density of luminous AGNs decreases more quickly than that of faint AGNs. We conclude that the anti-hierarchical evolution of the AGN space density is not contradictory to the hierarchical structure formation scenario.

  1. Anti-hierarchical evolution of the active galactic nucleus space density in a hierarchical universe

    International Nuclear Information System (INIS)

    Recent observations show that the space density of luminous active galactic nuclei (AGNs) peaks at higher redshifts than that of faint AGNs. This downsizing trend in the AGN evolution seems to be contradictory to the hierarchical structure formation scenario. In this study, we present the AGN space density evolution predicted by a semi-analytic model of galaxy and AGN formation based on the hierarchical structure formation scenario. We demonstrate that our model can reproduce the downsizing trend of the AGN space density evolution. The reason for the downsizing trend in our model is a combination of the cold gas depletion as a consequence of star formation, the gas cooling suppression in massive halos, and the AGN lifetime scaling with the dynamical timescale. We assume that a major merger of galaxies causes a starburst, spheroid formation, and cold gas accretion onto a supermassive black hole (SMBH). We also assume that this cold gas accretion triggers AGN activity. Since the cold gas is mainly depleted by star formation and gas cooling is suppressed in massive dark halos, the amount of cold gas accreted onto SMBHs decreases with cosmic time. Moreover, AGN lifetime increases with cosmic time. Thus, at low redshifts, major mergers do not always lead to luminous AGNs. Because the luminosity of AGNs is correlated with the mass of accreted gas onto SMBHs, the space density of luminous AGNs decreases more quickly than that of faint AGNs. We conclude that the anti-hierarchical evolution of the AGN space density is not contradictory to the hierarchical structure formation scenario.

  2. Hierarchical matrices algorithms and analysis

    CERN Document Server

    Hackbusch, Wolfgang

    2015-01-01

    This self-contained monograph presents matrix algorithms and their analysis. The new technique enables not only the solution of linear systems but also the approximation of matrix functions, e.g., the matrix exponential. Other applications include the solution of matrix equations, e.g., the Lyapunov or Riccati equation. The required mathematical background can be found in the appendix. The numerical treatment of fully populated large-scale matrices is usually rather costly. However, the technique of hierarchical matrices makes it possible to store matrices and to perform matrix operations approximately with almost linear cost and a controllable degree of approximation error. For important classes of matrices, the computational cost increases only logarithmically with the approximation error. The operations provided include the matrix inversion and LU decomposition. Since large-scale linear algebra problems are standard in scientific computing, the subject of hierarchical matrices is of interest to scientists ...

  3. Hierarchical Molecular Modelling with Ellipsoids

    Energy Technology Data Exchange (ETDEWEB)

    Max, N

    2004-03-29

    Protein and DNA structures are represented at varying levels of details using ellipsoidal RGBA textured splats. The splat texture at each level is generated by rendering its children in a hierarchical model, from a distribution of viewing directions, and averaging the result. For rendering, the ellipsoids to be used are chosen adaptively, depending on the distance to the viewpoint. This technique is applied to visualize DNA coiling around nucleosomes in chromosomes.

  4. Communication and optimal hierarchical networks

    OpenAIRE

    Guimera, R.; Arenas, A.; Diaz-Guilera, A.

    2001-01-01

    We study a general and simple model for communication processes. In the model, agents in a network (in particular, an organization) interchange information packets following simple rules that take into account the limited capability of the agents to deal with packets and the cost associated to the existence of open communication channels. Due to the limitation in the capability, the network collapses under certain conditions. We focus on when the collapse occurs for hierarchical networks and ...

  5. Nanomechanics of Hierarchical Cellular Solids

    OpenAIRE

    Chen, Qiang

    2012-01-01

    Materials Science and Engineering, a young and vibrant discipline with its inception in the 1950s, has expanded into three directions: metals, polymers, and ceramics (and their mixtures, composites). Beyond the traditional scope, biological materials have drawn much attention since 1990s due to their optimal structures, which rise from hundreds of million years of evolution. Generally, biological materials are complex composites and possess varieties of hierarchical structures, multifunctiona...

  6. Hierarchical image segmentation for learning object priors

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Lakshman [Los Alamos National Laboratory; Yang, Xingwei [TEMPLE UNIV.; Latecki, Longin J [TEMPLE UNIV.; Li, Nan [TEMPLE UNIV.

    2010-11-10

    The proposed segmentation approach naturally combines experience based and image based information. The experience based information is obtained by training a classifier for each object class. For a given test image, the result of each classifier is represented as a probability map. The final segmentation is obtained with a hierarchial image segmentation algorithm that considers both the probability maps and the image features such as color and edge strength. We also utilize image region hierarchy to obtain not only local but also semi-global features as input to the classifiers. Moreover, to get robust probability maps, we take into account the region context information by averaging the probability maps over different levels of the hierarchical segmentation algorithm. The obtained segmentation results are superior to the state-of-the-art supervised image segmentation algorithms.

  7. Hierarchical Bayesian sparse image reconstruction with application to MRFM

    CERN Document Server

    Dobigeon, Nicolas; Tourneret, Jean-Yves

    2008-01-01

    This paper presents a hierarchical Bayesian model to reconstruct sparse images when the observations are obtained from linear transformations and corrupted by an additive white Gaussian noise. Our hierarchical Bayes model is well suited to such naturally sparse image applications as it seamlessly accounts for properties such as sparsity and positivity of the image via appropriate Bayes priors. We propose a prior that is based on a weighted mixture of a positive exponential distribution and a mass at zero. The prior has hyperparameters that are tuned automatically by marginalization over the hierarchical Bayesian model. To overcome the complexity of the posterior distribution, a Gibbs sampling strategy is proposed. The Gibbs samples can be used to estimate the image to be recovered, e.g. by maximizing the estimated posterior distribution. In our fully Bayesian approach the posteriors of all the parameters are available. Thus our algorithm provides more information than other previously proposed sparse reconstr...

  8. Learning Hierarchical Spectral-Spatial Features for Hyperspectral Image Classification.

    Science.gov (United States)

    Zhou, Yicong; Wei, Yantao

    2016-07-01

    This paper proposes a spectral-spatial feature learning (SSFL) method to obtain robust features of hyperspectral images (HSIs). It combines the spectral feature learning and spatial feature learning in a hierarchical fashion. Stacking a set of SSFL units, a deep hierarchical model called the spectral-spatial networks (SSN) is further proposed for HSI classification. SSN can exploit both discriminative spectral and spatial information simultaneously. Specifically, SSN learns useful high-level features by alternating between spectral and spatial feature learning operations. Then, kernel-based extreme learning machine (KELM), a shallow neural network, is embedded in SSN to classify image pixels. Extensive experiments are performed on two benchmark HSI datasets to verify the effectiveness of SSN. Compared with state-of-the-art methods, SSN with a deep hierarchical architecture obtains higher classification accuracy in terms of the overall accuracy, average accuracy, and kappa ( κ ) coefficient of agreement, especially when the number of the training samples is small. PMID:26241988

  9. A novel load balancing method for hierarchical federation simulation system

    Science.gov (United States)

    Bin, Xiao; Xiao, Tian-yuan

    2013-07-01

    In contrast with single HLA federation framework, hierarchical federation framework can improve the performance of large-scale simulation system in a certain degree by distributing load on several RTI. However, in hierarchical federation framework, RTI is still the center of message exchange of federation, and it is still the bottleneck of performance of federation, the data explosion in a large-scale HLA federation may cause overload on RTI, It may suffer HLA federation performance reduction or even fatal error. Towards this problem, this paper proposes a load balancing method for hierarchical federation simulation system based on queuing theory, which is comprised of three main module: queue length predicting, load controlling policy, and controller. The method promotes the usage of resources of federate nodes, and improves the performance of HLA simulation system with balancing load on RTIG and federates. Finally, the experiment results are presented to demonstrate the efficient control of the method.

  10. Hierarchical Parallelism in Finite Difference Analysis of Heat Conduction

    Science.gov (United States)

    Padovan, Joseph; Krishna, Lala; Gute, Douglas

    1997-01-01

    Based on the concept of hierarchical parallelism, this research effort resulted in highly efficient parallel solution strategies for very large scale heat conduction problems. Overall, the method of hierarchical parallelism involves the partitioning of thermal models into several substructured levels wherein an optimal balance into various associated bandwidths is achieved. The details are described in this report. Overall, the report is organized into two parts. Part 1 describes the parallel modelling methodology and associated multilevel direct, iterative and mixed solution schemes. Part 2 establishes both the formal and computational properties of the scheme.

  11. Reconstruct the Hierarchical Structure in a Complex Network

    CERN Document Server

    Yang, H; Zhou, T; Ang, B; Zhao, F; Yang, Huijie; Wang, Wenxu; Zhou, Tao; ang, Binghong; Zhao, Fangcui

    2005-01-01

    A number of recent works have concentrated on a few statistical properties of complex networks, such as the clustering, the right-skewed degree distribution and the community, which are common to many real world networks. In this paper, we address the hierarchy property sharing among a large amount of networks. Based upon the eigenvector centrality (EC) measure, a method is proposed to reconstruct the hierarchical structure of a complex network. It is tested on the Santa Fe Institute collaboration network, whose structure is well known. We also apply it to a Mathematicians' collaboration network and the protein interaction network of Yeast. The method can detect significantly hierarchical structures in these networks.

  12. Growing self-organizing trees for autonomous hierarchical clustering.

    Science.gov (United States)

    Doan, Nhat-Quang; Azzag, Hanane; Lebbah, Mustapha

    2013-05-01

    This paper presents a new unsupervised learning method based on growing processes and autonomous self-assembly rules. This method, called Growing Self-organizing Trees (GSoT), can grow both network size and tree topology to represent the topological and hierarchical dataset organization, allowing a rapid and interactive visualization. Tree construction rules draw inspiration from elusive properties of biological organization to build hierarchical structures. Experiments conducted on real datasets demonstrate good GSoT performance and provide visual results that are generated during the training process. PMID:23041056

  13. Uncertainty in perception and the Hierarchical Gaussian Filter

    OpenAIRE

    Christoph Daniel Mathys; Lomakina, Ekaterina I.; Jean Daunizeau

    2014-01-01

    In its full sense, perception rests on an agent’s model of how its sensory input comes about and the inferences it draws based on this model. These inferences are necessarily uncertain. Here, we illustrate how the hierarchical Gaussian filter (HGF) offers a principled and generic way to deal with the several forms that uncertainty in perception takes. The HGF is a recent derivation of one-step update equations from Bayesian principles that rests on a hierarchical generative model of the envir...

  14. From coordination polymers to hierarchical self-assembled structures

    NARCIS (Netherlands)

    Yan, Y.; Keizer, de A.; Cohen Stuart, M.A.; Besseling, N.A.M.

    2011-01-01

    In this review, novel hierarchical self-assembled structures based on reversible organo-metallic supramolecular polymers are discussed. Firstly, we discuss recent advances in the field of coordination polymers, considering cases in which transition metal ions and bis- or multiligands are used to bui

  15. Dissimilarity Clustering by Hierarchical Multi-Level Refinement

    CERN Document Server

    Conan-Guez, Brieuc

    2012-01-01

    We introduce in this paper a new way of optimizing the natural extension of the quantization error using in k-means clustering to dissimilarity data. The proposed method is based on hierarchical clustering analysis combined with multi-level heuristic refinement. The method is computationally efficient and achieves better quantization errors than the

  16. Hierarchical Character-Word Models for Language Identification

    OpenAIRE

    Jaech, Aaron; Mulcaire, George; Hathi, Shobhit; Ostendorf, Mari; Smith, Noah A.

    2016-01-01

    Social media messages' brevity and unconventional spelling pose a challenge to language identification. We introduce a hierarchical model that learns character and contextualized word-level representations for language identification. Our method performs well against strong base- lines, and can also reveal code-switching.

  17. Hierarchical Control for Large-Scale Systems

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A class of large-seale systems, where the overall objective function is a nonlinear function of performance index of each subsystem, is investigated in this paper. This type of large-scale control problem is non-separable in the sense of conventional hierarchical control. Hierarchical control is extended in the paper to large-scale non-separable control problems, where multiobjective optimization is used as separation strategy. The large-scale non-separable control problem is embedded, under ;ertain conditions, into a family of the weighted Lagrangian formulation. The weighted Lagrangian formulation is separable with respect to subsystems and can be effectively solved using the interaction balance approach at the two lower levels in the proposed three-level solution structure. At the third level, the weighting vector for the weighted Lagrangian formulation is adjusted iteratively to search the optimal weighting vector with which the optimal of the original large-scale non-separable control problem is obtained. Theoretical base of the algorithm is established. Simulation shows that the algorithm is effective.

  18. Efficient scalable algorithms for hierarchically semiseparable matrices

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shen; Xia, Jianlin; Situ, Yingchong; Hoop, Maarten V. de

    2011-09-14

    Hierarchically semiseparable (HSS) matrix algorithms are emerging techniques in constructing the superfast direct solvers for both dense and sparse linear systems. Here, we develope a set of novel parallel algorithms for the key HSS operations that are used for solving large linear systems. These include the parallel rank-revealing QR factorization, the HSS constructions with hierarchical compression, the ULV HSS factorization, and the HSS solutions. The HSS tree based parallelism is fully exploited at the coarse level. The BLACS and ScaLAPACK libraries are used to facilitate the parallel dense kernel operations at the ne-grained level. We have appplied our new parallel HSS-embedded multifrontal solver to the anisotropic Helmholtz equations for seismic imaging, and were able to solve a linear system with 6.4 billion unknowns using 4096 processors, in about 20 minutes. The classical multifrontal solver simply failed due to high demand of memory. To our knowledge, this is the first successful demonstration of employing the HSS algorithms in solving the truly large-scale real-world problems. Our parallel strategies can be easily adapted to the parallelization of the other rank structured methods.

  19. Arabic Phoneme Recognition using Hierarchical Neural Fuzzy Petri Net and LPC Feature Extraction

    Directory of Open Access Journals (Sweden)

    Abduladhem

    2009-11-01

    Full Text Available The basic idea behind the proposed hierarchical phoneme recognition is that phonemes can be classified into specific phoneme types which can be organized within a hierarchical tree structure. The recognition principle is based on “divide and conquer” in which a large problem is divided into many smaller, easier to solve problems whose solutions can be combined to yield a solution to the complex problem. Fuzzy Petri net (FPN is a powerful modeling tool for fuzzy production rules based knowledge systems. For building hierarchical classifier using Neural Fuzzy Petri net (NFPN, Each node of the hierarchical tree is represented by a NFPN. Every NFPN in the hierarchical tree is trained by repeatedly presenting a set of input patterns along with the class to which each particular pattern belongs. The feature vector used as input to the NFPN is the LPC parameters.

  20. The Biomarker-Surrogacy Evaluation Schema: a review of the biomarker-surrogate literature and a proposal for a criterion-based, quantitative, multidimensional hierarchical levels of evidence schema for evaluating the status of biomarkers as surrogate endpoints.

    Science.gov (United States)

    Lassere, Marissa N

    2008-06-01

    There are clear advantages to using biomarkers and surrogate endpoints, but concerns about clinical and statistical validity and systematic methods to evaluate these aspects hinder their efficient application. Section 2 is a systematic, historical review of the biomarker-surrogate endpoint literature with special reference to the nomenclature, the systems of classification and statistical methods developed for their evaluation. In Section 3 an explicit, criterion-based, quantitative, multidimensional hierarchical levels of evidence schema - Biomarker-Surrogacy Evaluation Schema - is proposed to evaluate and co-ordinate the multiple dimensions (biological, epidemiological, statistical, clinical trial and risk-benefit evidence) of the biomarker clinical endpoint relationships. The schema systematically evaluates and ranks the surrogacy status of biomarkers and surrogate endpoints using defined levels of evidence. The schema incorporates the three independent domains: Study Design, Target Outcome and Statistical Evaluation. Each domain has items ranked from zero to five. An additional category called Penalties incorporates additional considerations of biological plausibility, risk-benefit and generalizability. The total score (0-15) determines the level of evidence, with Level 1 the strongest and Level 5 the weakest. The term ;surrogate' is restricted to markers attaining Levels 1 or 2 only. Surrogacy status of markers can then be directly compared within and across different areas of medicine to guide individual, trial-based or drug-development decisions. This schema would facilitate communication between clinical, researcher, regulatory, industry and consumer participants necessary for evaluation of the biomarker-surrogate-clinical endpoint relationship in their different settings. PMID:17925313

  1. Aircraft Detection in Remote Sensing Image Based on Hierarchical Classifiers%基于层次化分类器的遥感图像飞机目标检测

    Institute of Scientific and Technical Information of China (English)

    姚远; 姜志国; 张浩鹏

    2014-01-01

    Quick finding and counting aircraft objects and acquiring their accurate positions in a number of space and aviation remote sensing images, are of great significance both in military and civilian applica-tions.According to the characteristics of remote sensing images and the features of aircraft objects, a new method is designed for aircraft detection in remote sensing images which makes use of the hierarchical classi-fiers. Firstly, bottom AdaBoost classifiers based on Haar features are used to quickly filter out most of the non-aircraft areas.Then top SVM (Support Vector Machine) classifiers based on HOG (Histogram of Oriented Gradient) features are applied for fine recognition.The experimental results in remote sensing image dataset with the resolution of 1m show that hierarchical classifiers can greatly reduce the false alarm rate with high detection rate, so this method can effectively solve the problem of aircraft detection in remote sensing image.%在大量航空航天遥感图像中,快速发现和统计飞机目标并对其进行准确定位,在军事和民用方面均具有重要意义。结合遥感图像特点,针对飞机目标的特征,文章设计了一种基于层次化的分类器的遥感图像飞机目标检测方法。首先用基于哈尔(Haar)特征的底层AdaBoost分类器快速去除大部分非目标区域;然后用基于梯度方向直方图(Histogram of Oriented Gradient,HOG)特征的顶层支持向量机(Support Vector Machine,SVM)分类器进行精细检测。在分辨率为1m的遥感图像数据集上的实验结果表明,层次化分类器在保证较高检测率的前提下,大大降低了虚警率,可以有效解决遥感图像飞机检测问题。

  2. The MIL-88A-Derived Fe3O4-Carbon Hierarchical Nanocomposites for Electrochemical Sensing

    Science.gov (United States)

    Wang, Li; Zhang, Yayun; Li, Xia; Xie, Yingzhen; He, Juan; Yu, Jie; Song, Yonghai

    2015-09-01

    Metal or metal oxides/carbon nanocomposites with hierarchical superstructures have become one of the most promising functional materials in sensor, catalysis, energy conversion, etc. In this work, novel hierarchical Fe3O4/carbon superstructures have been fabricated based on metal-organic frameworks (MOFs)-derived method. Three kinds of Fe-MOFs (MIL-88A) with different morphologies were prepared beforehand as templates, and then pyrolyzed to fabricate the corresponding novel hierarchical Fe3O4/carbon superstructures. The systematic studies on the thermal decomposition process of the three kinds of MIL-88A and the effect of template morphology on the products were carried out in detail. Scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy and thermal analysis were employed to investigate the hierarchical Fe3O4/carbon superstructures. Based on these resulted hierarchical Fe3O4/carbon superstructures, a novel and sensitive nonenzymatic N-acetyl cysteine sensor was developed. The porous and hierarchical superstructures and large surface area of the as-formed Fe3O4/carbon superstructures eventually contributed to the good electrocatalytic activity of the prepared sensor towards the oxidation of N-acetyl cysteine. The proposed preparation method of the hierarchical Fe3O4/carbon superstructures is simple, efficient, cheap and easy to mass production. It might open up a new way for hierarchical superstructures preparation.

  3. The hierarchical structure of chemical engineering

    Institute of Scientific and Technical Information of China (English)

    Mooson KWAUK

    2007-01-01

    Around the turn of the present century, scholars began to recognize chemical engineering as a complex system, and have been searching for a convenient point of entry for refreshing its knowledge base. From our study of the dynamic structures of dispersed particles in fluidization and the resulting multi-scale method, we have been attempting to extend our findings to structures prevailing in other multiphase systems as well as in the burgeoning industries producing functional materials. Chemical engineering itself is hierarchically structured. Besides structures based on space and time, such hierarchy could be built from ChE history scaled according to science content, or from ChE operation according to the expenditure of manpower and capital investment.

  4. The hierarchical structure of chemical engineering

    Institute of Scientific and Technical Information of China (English)

    Mooson; KWAUK

    2007-01-01

    Around the turn of the present century,scholars began to recognize chemical engineering as a com-plex system,and have been searching for a convenient point of entry for refreshing its knowledge base.From our study of the dynamic structures of dispersed particles in fluidization and the resultingmulti-scale method,we have been attempting to extend our findings to structures prevailing in othermultiphase systems as well as in the burgeoning industries producing functional materials.Chemicalengineering itself is hierarchically structured.Besides structures based on space and time,such hier-archy could be built from ChE history scaled according to science content,or from ChE operation ac-cording to the expenditure of manpower and capital investment.

  5. A Hierarchical Approach to Fracture Mechanics

    Science.gov (United States)

    Saether, Erik; Taasan, Shlomo

    2004-01-01

    Recent research conducted under NASA LaRC's Creativity and Innovation Program has led to the development of an initial approach for a hierarchical fracture mechanics. This methodology unites failure mechanisms occurring at different length scales and provides a framework for a physics-based theory of fracture. At the nanoscale, parametric molecular dynamic simulations are used to compute the energy associated with atomic level failure mechanisms. This information is used in a mesoscale percolation model of defect coalescence to obtain statistics of fracture paths and energies through Monte Carlo simulations. The mathematical structure of predicted crack paths is described using concepts of fractal geometry. The non-integer fractal dimension relates geometric and energy measures between meso- and macroscales. For illustration, a fractal-based continuum strain energy release rate is derived for inter- and transgranular fracture in polycrystalline metals.

  6. Stability criteria for hierarchical triple systems

    CERN Document Server

    Georgakarakos, Nikolaos

    2014-01-01

    In this paper, we give a summary of stability criteria that have been derived for hierarchical triple systems over the past few decades. We give a brief description and we discuss the criteria that are based on the generalisation of the concept of zero velocity surfaces of the restricted three body problem, to the general case. We also present criteria that have to do with escape of one of the bodies. Then, we talk about the criteria that have been derived using data from numerical integrations. Finally, we report on criteria that involve the concept of chaos. In all cases, wherever possible, we discuss advantages and disadvantages of the criteria and the methods their derivation was based on, and some comparison is made in several cases.

  7. 基于分层模糊优化的湿式多片离合器起步控制研究%Study of Wet Multi- plate Clutch Starting Control based on Hierarchical Fuzzy Optimization

    Institute of Scientific and Technical Information of China (English)

    闫光辉; 关志伟; 童敏勇

    2012-01-01

    According to the control theory of wet multi - plate clutch and starting process, taking full account of starting impact and sliding friction works, the starting process is analyzed and the control parameters of each starting process are selected. And then the hierarchical fuzzy optimization control strategy of clutch engagement occupation -empty ratio is proposed, which means the first analysis of starting intention, followed by initial occupation - empty ra-tio control, and finally to optimize occupation - empty ratio. Based on the control strategy, the control model and algo-rithm of hierarchical fuzzy optimization is designed. After vehicle simulation and compare with other control strategies, the results show that the strategy can effectively identify the driver s starting intention, improve the smoothness of the wet clutch and reduce the starting impact and sliding friction works.%针对湿式多片离合器的控制原理和起步结合过程,在充分考虑起步冲击度和滑磨功的基础上,分析了起步过程,选取了各起步过程的控制参数.继而提出了离合器起步占空比分层模糊优化控制策略,即首先分析起步意图,其次对占空比进行初始控制,最后对占空比进行优化.在此控制策略的基础上设计了分层模糊优化的控制模型和算法.经过整车仿真,并与其他控制策略对比,结果显示该策略能有效识别驾驶员起步意图,提高湿式离合器的起步平顺性,并能降低冲击度和滑磨功.

  8. Optimization Method of Route Guidance Based on the Twice Hierarchical Model of Road Network%基于路网二次分层模型的出行路径诱导优化方法

    Institute of Scientific and Technical Information of China (English)

    潘大为; 邓卫; 季彦婕

    2013-01-01

    A twice hierarchical model based on the function and traffic state of a road network was developed for improving the searching efficiency and benefit of route guidance. The model first partitioned the road network by the function of road network, then, concerning the traffic state, the net was partitioned into different layers using the defined threshold values. A twice hierarchical model was established, which could represent the road net macro-structure, and micro-traffic operation parameters. By the cooperation between the different layers, the paper used the A* algorithm to search the optimal route through the 3-segment routing within restricted search area. A case study was presented to verify the application of the proposed model. The results show that the model is helpful to choose the optimal travel route.%  为了提高出行诱导路径搜索的效率和优度,提出了一种基于道路功能以及交通状态划分的路网二次分层模型,模型从道路的功能角度进行路网的初分层,从道路交通状态角度,通过设定的交通状态阈值进行路网的次分层,建立的路网二次分层模型从宏观方面反映路网的结构,从微观方面反映路网运行的交通参数;利用路网二次分层模型所划分的各层路网之间的协同,借助限制区域的A*算法进行最优路径的“三段巡径”过程。实例表明该算法实用、高效,有助于搜索得到最优出行路径。

  9. Boundaries and automorphisms of hierarchically hyperbolic spaces

    OpenAIRE

    Durham, Matthew G.; Hagen, Mark F.; Sisto, Alessandro

    2016-01-01

    Hierarchically hyperbolic spaces provide a common framework for studying mapping class groups of finite type surfaces, Teichm\\"uller space, right-angled Artin groups, and many other cubical groups. Given such a space $\\mathcal X$, we build a bordification of $\\mathcal X$ compatible with its hierarchically hyperbolic structure. If $\\mathcal X$ is proper, e.g. a hierarchically hyperbolic group such as the mapping class group, we get a compactification of $\\mathcal X$; we also prove our construc...

  10. Low energy isomers of (H2O)25 from a hierarchical method based on Monte Carlo Temperature Basin Paving and Molecular Tailoring Approaches benchmarked by full MP2 calculations

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, Nityananda; Gadre, Shridhar R.; Bandyopadhyay, Pradipta; Miliordos, Evangelos; Xantheas, Sotiris S.

    2014-10-28

    We report new global minimum candidate structures for the (H2O)25 cluster that are lower in energy than the ones reported previously and correspond to hydrogen bonded networks with 42 hydrogen bonds and an interior, fully coordinated water molecule. These were obtained as a result of a hierarchical approach based on initial Monte Carlo Temperature Basin Paving (MCTBP) sampling of the cluster’s Potential Energy Surface (PES) with the Effective Fragment Potential (EFP), subsequent geometry optimization using the Molecular Tailoring fragmentation Approach (MTA) and final refinement at the second order Møller Plesset perturbation (MP2) level of theory. The MTA geometry optimizations used between 14 and 18 main fragments with maximum sizes between 11 and 14 water molecules and average size of 10 water molecules, whose energies and gradients were computed at the MP2 level. The MTA-MP2 optimized geometries were found to be quite close (within < 0.5 kcal/mol) to the ones obtained from the MP2 optimization of the whole cluster. The grafting of the MTA-MP2 energies yields electronic energies that are within < 5×10-4 a.u. from the MP2 results for the whole cluster while preserving their energy order. The MTA-MP2 method was also found to reproduce the MP2 harmonic vibrational frequencies in both the HOH bending and the OH stretching regions.

  11. Energy Consumption Analysis of Green Computing Ecosystem Based on Hierarchical Structure%基于层次结构的绿色计算生态系统能耗分析

    Institute of Scientific and Technical Information of China (English)

    刘友生

    2013-01-01

    针对云计算中能源消耗缺少全面分析和度量的问题,从生态系统角度出发,提出基于层次结构的绿色计算生态系统,设计绿色计算生态系统能耗分析模型,并对其能耗因子进行分析.通过ACTTest实验测试程序,对绿色计算生态系统中的Web构件、集群技术和调用开销能耗进行测试.测试结果表明,该系统具有较好的节能效果,并且可实现绿色计算.%Aiming at the lack of a comprehensive analysis and metrics for energy consumption in the cloud computing, and from a view of ecosystem, the concept of green computing ecosystem based on the hierarchical structure is presented, and its analysis model is designed. In addition, the energy consumption factors in the structure of green computing ecosystem are analyzed in this paper. With the design of ACTTest experimental test program, the Web components of the system, cluster technology and the energy consumption of call spending are mainly tested. Experimental results show that this system can improve the efficiency in saving energy and it enables the green computing.

  12. Coherent dynamics on hierarchical systems

    Science.gov (United States)

    Blumen, Alexander; Bierbaum, Veronika; Mülken, Oliver

    2006-11-01

    We study the coherent transport modeled by continuous-time quantum walks, focussing on hierarchical structures. For these we use Husimi cacti, lattices dual to the dendrimers. We find that the transport depends strongly on the initial site of the excitation. For systems of sizes N⩽21, we find that processes which start at central sites are nearly recurrent. Furthermore, we compare the classical limiting probability distribution to the long time average of the quantum mechanical transition probability which shows characteristic patterns. We succeed in finding a good lower bound for the (space) average of the quantum mechanical probability to be still or again at the initial site.

  13. Hierarchical Control for Smart Grids

    DEFF Research Database (Denmark)

    Trangbæk, K; Bendtsen, Jan Dimon; Stoustrup, Jakob

    2011-01-01

    This paper deals with hierarchical model predictive control (MPC) of smart grid systems. The design consists of a high level MPC controller, a second level of so-called aggregators, which reduces the computational and communication-related load on the high-level control, and a lower level of...... autonomous consumers. The control system is tasked with balancing electric power production and consumption within the smart grid, and makes active use of the flexibility of a large number of power producing and/or power consuming units. The objective is to accommodate the load variation on the grid, arising...

  14. Hierarchical Image Saliency Detection on Extended CSSD.

    Science.gov (United States)

    Shi, Jianping; Yan, Qiong; Xu, Li; Jia, Jiaya

    2016-04-01

    Complex structures commonly exist in natural images. When an image contains small-scale high-contrast patterns either in the background or foreground, saliency detection could be adversely affected, resulting erroneous and non-uniform saliency assignment. The issue forms a fundamental challenge for prior methods. We tackle it from a scale point of view and propose a multi-layer approach to analyze saliency cues. Different from varying patch sizes or downsizing images, we measure region-based scales. The final saliency values are inferred optimally combining all the saliency cues in different scales using hierarchical inference. Through our inference model, single-scale information is selected to obtain a saliency map. Our method improves detection quality on many images that cannot be handled well traditionally. We also construct an extended Complex Scene Saliency Dataset (ECSSD) to include complex but general natural images. PMID:26959676

  15. Implementation of hierarchical control in DC microgrids

    DEFF Research Database (Denmark)

    Jin, Chi; Wang, Peng; Xiao, Jianfang; Tang, Yi; Choo, Fook Hoong

    2014-01-01

    DC microgrids are becoming popular in low-voltage distribution systems due to the better compatibility with photovoltaic panels, electric vehicles, and dc loads. This paper presents a practical dc microgrid developed in the Water and Energy Research Laboratory (WERL) in the Nanyang University of...... Technology, Singapore. The coordination control among multiple dc sources and energy storages is implemented using a novel hierarchical control technique. The bus voltage essentially acts as an indicator of supply-demand balance. A wireless control is implemented for the reliable operation of the grid. A...... reasonable compromise between the maximum power harvest and effective battery management is further enhanced using the coordination control based on a central energy management system. The feasibility and effectiveness of the proposed control strategies have been tested by a dc microgrid in WERL....

  16. Hierarchical Subtopic Segmentation of Web Document

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The paper proposes a novel method for subtopics segmentation of Web document. An effective retrieval results may be obtained by using subtopics segmentation. The proposed method can segment hierarchically subtopics and identify the boundary of each subtopic. Based on the term frequency matrix, the method measures the similarity between adjacent blocks, such as paragraphs, passages. In the real-world sample experiment, the macro-averaged precision and recall reach 73.4% and 82.5%, and the micro-averaged precision and recall reach 72.9% and 83.1%. Moreover, this method is equally efficient to other Asian languages such as Japanese and Korean, as well as other western languages.

  17. Hierarchical modeling of active materials

    International Nuclear Information System (INIS)

    Intelligent (or smart) materials are increasingly becoming key materials for use in actuators and sensors. If an intelligent material is used as a sensor, it can be embedded in a variety of structure functioning as a health monitoring system to make their life longer with high reliability. If an intelligent material is used as an active material in an actuator, it plays a key role of making dynamic movement of the actuator under a set of stimuli. This talk intends to cover two different active materials in actuators, (1) piezoelectric laminate with FGM microstructure, (2) ferromagnetic shape memory alloy (FSMA). The advantage of using the FGM piezo laminate is to enhance its fatigue life while maintaining large bending displacement, while that of use in FSMA is its fast actuation while providing a large force and stroke capability. Use of hierarchical modeling of the above active materials is a key design step in optimizing its microstructure for enhancement of their performance. I will discuss briefly hierarchical modeling of the above two active materials. For FGM piezo laminate, we will use both micromechanical model and laminate theory, while for FSMA, the modeling interfacing nano-structure, microstructure and macro-behavior is discussed. (author)

  18. Memory efficient hierarchical error diffusion

    Science.gov (United States)

    He, Zhen; Fan, Zhigang

    2010-01-01

    Hierarchical Error Diffusion (HED) developed in [14] yields high-quality color halftone by explicitly designing three critical factors: dot overlapping, positioning, and coloring. However, HED requires more error memory buffer than the conventional error diffusion algorithms since the pixel error is diffused in dot-color domain, instead of colorant domain. This can potentially be an issue for certain low-cost hardware implementation. This paper develops a memory-efficient HED algorithm (MEHED). To achieve this goal, the pixel error in dot-color domain is converted backward and diffused to future pixels in input colorant domain, say, CMYK for print applications. Since the error-augmented pixel value is no longer bounded within the range [0, 1.0], the dot overlapping control algorithm developed in [14] needs to be generalized to coherently handle the pixel density of outside the normal range. The key is to carefully split the modified pixel density into three parts: negative, regular, and surplus densities. The determination of regular and surplus densities needs to be dependent on the density of K channel, in order to maintain local color and avoid halftone texture artifact. The resulting dot-color densities are serves as the input to hierarchical thresholding and coloring steps to generate final halftone output. Experimental results demonstrate that MEHED achieves similar image quality compared to HED.

  19. Hierarchical organisation of causal graphs

    International Nuclear Information System (INIS)

    This paper deals with the design of a supervision system using a hierarchy of models formed by graphs, in which the variables are the nodes and the causal relations between the variables of the arcs. To obtain a representation of the variables evolutions which contains only the relevant features of their real evolutions, the causal relations are completed with qualitative transfer functions (QTFs) which produce roughly the behaviour of the classical transfer functions. Major improvements have been made in the building of the hierarchical organization. First, the basic variables of the uppermost level and the causal relations between them are chosen. The next graph is built by adding intermediary variables to the upper graph. When the undermost graph has been built, the transfer functions parameters corresponding to its causal relations are identified. The second task consists in the upwelling of the information from the undermost graph to the uppermost one. A fusion procedure of the causal relations has been designed to compute the QFTs relevant for each level. This procedure aims to reduce the number of parameters needed to represent an evolution at a high level of abstraction. These techniques have been applied to the hierarchical modelling of nuclear process. (authors). 8 refs., 12 figs

  20. A Multilevel Secure Relation-Hierarchical Data Model for a Secure DBMS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A multilevel secure relation-hierarchical data model formultilevel secure database is extended from the relation-hierarchical data model in single level environment in this paper. Based on the model, an upper-lower layer relational integrity is presented after we analyze and eliminate the covert channels caused by the database integrity. Two SQL statements are extended to process polyinstantiation in the multilevel secure environment. The system based on the multilevel secure relation-hierarchical data model is capable of integratively storing and manipulating complicated objects (e.g., multilevel spatial data) and conventional data (e.g., integer, real number and character string) in multilevel secure database.

  1. Penerapan Metode Angglomerative Hierarchical Clustering untuk Klasifikasi Kabupaten/Kota di Propinsi Jawa Timur Berdasarkan Kualitas Pelayanan Keluarga Berencana

    OpenAIRE

    Alfi Fadliana; Fachrur Rozi

    2015-01-01

    Agglomerative hierarchical clustering methods is cluster analysis method whose primary purpose is to group objects based on its characteristics, it begins with the individual objects until the objects are fused into a single cluster. Agglomerative hierarchical clustering methods are divided into single linkage, complete linkage, average linkage, and ward. This research compared the four agglomerative hierarchical clustering methods in order to get the best cluster solution in the case of the ...

  2. Mapping urban and peri-urban breeding habitats of Aedes mosquitoes using a fuzzy analytical hierarchical process based on climatic and physical parameters.

    Science.gov (United States)

    Sarfraz, Muhammad Shahzad; Tripathi, Nagesh K; Faruque, Fazlay S; Bajwa, Usama Ijaz; Kitamoto, Asanobu; Souris, Marc

    2014-01-01

    The spread of dengue fever depends mainly on the availability of favourable breeding sites for its mosquito vectors around human dwellings. To investigate if the various factors influencing breeding habitats can be mapped from space, dengue indices, such as the container index, the house index and the Breteau index, were calculated from Ministry of Public health data collected three times annually in Phitsanulok, Thailand between 2009 and 2011. The most influential factors were found to be temperature, humidity, rainfall, population density, elevation and land cover. Models were worked out using parameters mostly derived from freely available satellite images and fuzzy logic software with parameter synchronisation and a predication algorithm based on data mining and the Decision Tree method. The models developed were found to be sufficiently flexible to accommodate additional parameters and sampling data that might improve prediction of favourable breeding hotspots. The algorithm applied can not only be used for the prediction of near real-time scenarios with respect to dengue, but can also be applied for monitoring other diseases influenced by environmental and climatic factors. The multi-criteria model presented is a cost-effective way of identifying outbreak hotspots and early warning systems lend themselves for development based on this strategy. The proposed approach demonstrates the successful utilisation of remotely sensed images to map mosquito breeding habitats. PMID:25599639

  3. Mapping urban and peri-urban breeding habitats of Aedes mosquitoes using a fuzzy analytical hierarchical process based on climatic and physical parameters

    Directory of Open Access Journals (Sweden)

    Muhammad Shahzad Sarfraz

    2014-12-01

    Full Text Available The spread of dengue fever depends mainly on the availability of favourable breeding sites for its mosquito vectors around human dwellings. To investigate if the various factors influencing breeding habitats can be mapped from space, dengue indices, such as the container index, the house index and the Breteau index, were calculated from Ministry of Public health data collected three times annually in Phitsanulok, Thailand between 2009 and 2011. The most influential factors were found to be temperature, humidity, rainfall, population density, elevation and land cover. Models were worked out using parameters mostly derived from freely available satellite images and fuzzy logic software with parameter synchronisation and a predication algorithm based on data mining and the Decision Tree method. The models developed were found to be sufficiently flexible to accommodate additional parameters and sampling data that might improve prediction of favourable breeding hotspots. The algorithm applied can not only be used for the prediction of near real-time scenarios with respect to dengue, but can also be applied for monitoring other diseases influenced by environmental and climatic factors. The multi-criteria model presented is a cost-effective way of identifying outbreak hotspots and early warning systems lend themselves for development based on this strategy. The proposed approach demonstrates the successful utilisation of remotely sensed images to map mosquito breeding habitats.

  4. Supervised learning in hierarchical neural networks for edge enhancement

    Science.gov (United States)

    Lu, Si W.; Szeto, Anthony

    1992-09-01

    Hierarchical artificial neural networks are designed to enhance edge measurement. The neural network comprises four subnets: the Edge Contour Detection subnet, the Maximum Detection subnet, the Gradient Adjustment subnet, and the Orientation Determination subnet. The interconnections between these subnets are fashioned in a hierarchical manner. In order for the neural network system to perform correctly and accurately, each of the neural subnets must be given suitable weights by learning. The learning is very difficult for the hierarchical neural networks because of the complicated hierarchical structure. In our learning algorithm the modularity is introduced for fast learning and good generalization, based on the analysis of the local concept and the distributed concept represented by the module. The amount of information which the nets need to learn is drastically reduced. Therefore, only a small number of training patterns are required to train the nets and still derive suitable weights for the nets to perform accurately and efficiently. The neural network is simulated on a MIPS M120-S machine running UNIX. For the test images degraded by random noise up to 20%, the true edges are detected and enhanced, the false edges are suppressed, the noise is eliminated, the weak edges are reinforced, and the missing edge elements are interpolated.

  5. Hierarchical Coding Vectors for Scene Level Land-Use Classification

    Directory of Open Access Journals (Sweden)

    Hang Wu

    2016-05-01

    Full Text Available Land-use classification from remote sensing images has become an important but challenging task. This paper proposes Hierarchical Coding Vectors (HCV, a novel representation based on hierarchically coding structures, for scene level land-use classification. We stack multiple Bag of Visual Words (BOVW coding layers and one Fisher coding layer to develop the hierarchical feature learning structure. In BOVW coding layers, we extract local descriptors from a geographical image with densely sampled interest points, and encode them using soft assignment (SA. The Fisher coding layer encodes those semi-local features with Fisher vectors (FV and aggregates them to develop a final global representation. The graphical semantic information is refined by feeding the output of one layer into the next computation layer. HCV describes the geographical images through a high-level representation of richer semantic information by using a hierarchical coding structure. The experimental results on the 21-Class Land Use (LU and RSSCN7 image databases indicate the effectiveness of the proposed HCV. Combined with the standard FV, our method (FV + HCV achieves superior performance compared to the state-of-the-art methods on the two databases, obtaining the average classification accuracy of 91.5% on the LU database and 86.4% on the RSSCN7 database.

  6. Ferritic Alloys with Extreme Creep Resistance via Coherent Hierarchical Precipitates

    Science.gov (United States)

    Song, Gian; Sun, Zhiqian; Li, Lin; Xu, Xiandong; Rawlings, Michael; Liebscher, Christian H.; Clausen, Bjørn; Poplawsky, Jonathan; Leonard, Donovan N.; Huang, Shenyan; Teng, Zhenke; Liu, Chain T.; Asta, Mark D.; Gao, Yanfei; Dunand, David C.; Ghosh, Gautam; Chen, Mingwei; Fine, Morris E.; Liaw, Peter K.

    2015-11-01

    There have been numerous efforts to develop creep-resistant materials strengthened by incoherent particles at high temperatures and stresses in response to future energy needs for steam turbines in thermal-power plants. However, the microstructural instability of the incoherent-particle-strengthened ferritic steels limits their application to temperatures below 900 K. Here, we report a novel ferritic alloy with the excellent creep resistance enhanced by coherent hierarchical precipitates, using the integrated experimental (transmission-electron microscopy/scanning-transmission-electron microscopy, in-situ neutron diffraction, and atom-probe tomography) and theoretical (crystal-plasticity finite-element modeling) approaches. This alloy is strengthened by nano-scaled L21-Ni2TiAl (Heusler phase)-based precipitates, which themselves contain coherent nano-scaled B2 zones. These coherent hierarchical precipitates are uniformly distributed within the Fe matrix. Our hierarchical structure material exhibits the superior creep resistance at 973 K in terms of the minimal creep rate, which is four orders of magnitude lower than that of conventional ferritic steels. These results provide a new alloy-design strategy using the novel concept of hierarchical precipitates and the fundamental science for developing creep-resistant ferritic alloys. The present research will broaden the applications of ferritic alloys to higher temperatures.

  7. Hierarchical decision making for flood risk reduction

    DEFF Research Database (Denmark)

    Custer, Rocco; Nishijima, Kazuyoshi

    2013-01-01

    River flood events often cause large economic damages and casualties requiring stakeholders to manage flood risk. In flood prone areas, flood risk management can be achieved through a series hierarchically integrated protection structures, which together form a hierarchical flood protection system...

  8. The Case for a Hierarchical Cosmology

    Science.gov (United States)

    Vaucouleurs, G. de

    1970-01-01

    The development of modern theoretical cosmology is presented and some questionable assumptions of orthodox cosmology are pointed out. Suggests that recent observations indicate that hierarchical clustering is a basic factor in cosmology. The implications of hierarchical models of the universe are considered. Bibliography. (LC)

  9. Complexity and hierarchical game of life

    OpenAIRE

    Gotz, Ivan; Rubinstein, Isaak; Tsvetkov, Eugene; Zaltzman, Boris

    2003-01-01

    Hierarchical structure is an essential part of complexity, important notion relevant for a wide range of applications ranging from biological population dynamics through robotics to social sciences. In this paper we propose a simple cellular-automata tool for study of hierarchical population dynamics.

  10. Hierarchical Classes Modeling of Rating Data

    Science.gov (United States)

    Van Mechelen, Iven; Lombardi, Luigi; Ceulemans, Eva

    2007-01-01

    Hierarchical classes (HICLAS) models constitute a distinct family of structural models for N-way N-mode data. All members of the family include N simultaneous and linked classifications of the elements of the N modes implied by the data; those classifications are organized in terms of hierarchical, if-then-type relations. Moreover, the models are…

  11. Rational design of hierarchically porous birnessite-type manganese dioxides nanosheets on different one-dimensional titania-based nanowires for high performance supercapacitors

    KAUST Repository

    Zhang, Yu Xin

    2014-12-01

    A facile and large-scale strategy of mesoporous birnessite-type manganese dioxide (MnO2) nanosheets on one-dimension (1D) H2Ti 3O7 and anatase/TiO2 (B) nanowires (NWs) is developed for high performance supercapacitors. The morphological characteristics of MnO2 nanoflakes on H2Ti 3O7 and anatase/TiO2 (B) NWs could be rationally designed with various characteristics (e.g., the sheet thickness, surface area). Interestingly, the MnO2/TiO2 NWs exhibit a more optimized electrochemical performance with specific capacitance of 120 F g-1 at current density of 0.1 A g-1 (based on MnO 2 + TiO2) than MnO2/H2Ti 3O7 NWs. An asymmetric supercapacitor of MnO 2/TiO2//activated graphene (AG) yields a better energy density of 29.8 Wh kg-1 than MnO2/H2Ti 3O7//AG asymmetric supercapacitor, while maintaining desirable cycling stability. Indeed, the pseudocapacitive difference is related to the substrates, unique structure and surface area. Especially, the anatase/TiO2 (B) mixed-phase system can provide good electronic conductivity and high utilization of MnO2 nanosheets. © 2014 Elsevier B.V. All rights reserved.

  12. Hierarchically Nanostructured Materials for Sustainable Environmental Applications

    Directory of Open Access Journals (Sweden)

    Zheng eRen

    2013-11-01

    Full Text Available This article presents a comprehensive overview of the hierarchical nanostructured materials with either geometry or composition complexity in environmental applications. The hierarchical nanostructures offer advantages of high surface area, synergistic interactions and multiple functionalities towards water remediation, environmental gas sensing and monitoring as well as catalytic gas treatment. Recent advances in synthetic strategies for various hierarchical morphologies such as hollow spheres and urchin-shaped architectures have been reviewed. In addition to the chemical synthesis, the physical mechanisms associated with the materials design and device fabrication have been discussed for each specific application. The development and application of hierarchical complex perovskite oxide nanostructures have also been introduced in photocatalytic water remediation, gas sensing and catalytic converter. Hierarchical nanostructures will open up many possibilities for materials design and device fabrication in environmental chemistry and technology.

  13. Hierarchically Nanostructured Materials for Sustainable Environmental Applications

    Science.gov (United States)

    Ren, Zheng; Guo, Yanbing; Liu, Cai-Hong; Gao, Pu-Xian

    2013-11-01

    This article presents a comprehensive overview of the hierarchical nanostructured materials with either geometry or composition complexity in environmental applications. The hierarchical nanostructures offer advantages of high surface area, synergistic interactions and multiple functionalities towards water remediation, environmental gas sensing and monitoring as well as catalytic gas treatment. Recent advances in synthetic strategies for various hierarchical morphologies such as hollow spheres and urchin-shaped architectures have been reviewed. In addition to the chemical synthesis, the physical mechanisms associated with the materials design and device fabrication have been discussed for each specific application. The development and application of hierarchical complex perovskite oxide nanostructures have also been introduced in photocatalytic water remediation, gas sensing and catalytic converter. Hierarchical nanostructures will open up many possibilities for materials design and device fabrication in environmental chemistry and technology.

  14. Hierarchical mutual information for the comparison of hierarchical community structures in complex networks

    CERN Document Server

    Perotti, Juan Ignacio; Caldarelli, Guido

    2015-01-01

    The quest for a quantitative characterization of community and modular structure of complex networks produced a variety of methods and algorithms to classify different networks. However, it is not clear if such methods provide consistent, robust and meaningful results when considering hierarchies as a whole. Part of the problem is the lack of a similarity measure for the comparison of hierarchical community structures. In this work we give a contribution by introducing the {\\it hierarchical mutual information}, which is a generalization of the traditional mutual information, and allows to compare hierarchical partitions and hierarchical community structures. The {\\it normalized} version of the hierarchical mutual information should behave analogously to the traditional normalized mutual information. Here, the correct behavior of the hierarchical mutual information is corroborated on an extensive battery of numerical experiments. The experiments are performed on artificial hierarchies, and on the hierarchical ...

  15. Design and Characterisation of a Novel Artificial Life System Incorporating Hierarchical Selection

    OpenAIRE

    Kelly, Ciarán

    2010-01-01

    In this thesis, a minimal artificial chemistry system is presented, which is inspired by the RNA World hypothesis and is loosely based on Holland's Learning Classier Systems. The Molecular Classier System (MCS) takes a bottom-up, individual-based approach to building artificial bio-chemical networks. The MCS has been developed to demonstrate the effects of hierarchical selection. Hierarchical selection appears to have been critical for the evolution of complexity in life as we know it yet, ...

  16. HIERARCHICAL FRAGMENTATION OF THE ORION MOLECULAR FILAMENTS

    International Nuclear Information System (INIS)

    We present a high angular resolution map of the 850 μm continuum emission of the Orion Molecular Cloud-3 (OMC 3) obtained with the Submillimeter Array (SMA); the map is a mosaic of 85 pointings covering an approximate area of 6.'5 × 2.'0 (0.88 × 0.27 pc). We detect 12 spatially resolved continuum sources, each with an H2 mass between 0.3-5.7 M ☉ and a projected source size between 1400-8200 AU. All the detected sources are on the filamentary main ridge (nH2≥106 cm–3), and analysis based on the Jeans theorem suggests that they are most likely gravitationally unstable. Comparison of multi-wavelength data sets indicates that of the continuum sources, 6/12 (50%) are associated with molecular outflows, 8/12 (67%) are associated with infrared sources, and 3/12 (25%) are associated with ionized jets. The evolutionary status of these sources ranges from prestellar cores to protostar phase, confirming that OMC-3 is an active region with ongoing embedded star formation. We detect quasi-periodical separations between the OMC-3 sources of ≈17''/0.035 pc. This spatial distribution is part of a large hierarchical structure that also includes fragmentation scales of giant molecular cloud (≈35 pc), large-scale clumps (≈1.3 pc), and small-scale clumps (≈0.3 pc), suggesting that hierarchical fragmentation operates within the Orion A molecular cloud. The fragmentation spacings are roughly consistent with the thermal fragmentation length in large-scale clumps, while for small-scale cores it is smaller than the local fragmentation length. These smaller spacings observed with the SMA can be explained by either a helical magnetic field, cloud rotation, or/and global filament collapse. Finally, possible evidence for sequential fragmentation is suggested in the northern part of the OMC-3 filament.

  17. Dimensionality and hierarchical structure of disability measurement.

    Science.gov (United States)

    van Boxel, Y J; Roest, F H; Bergen, M P; Stam, H J

    1995-12-01

    Since the D-code of the International Classification of Impairments, Disabilities, and Handicaps (ICIDH) in its full form has proven to be impractical, an instrument based on a selection of 28 items is used to measure disability in Dutch patients undergoing rehabilitation. The items are categorized into 5 domains of physical, activities of daily living (ADL), social, psychological, and communicative activity. Measurement is made on a 4-point scale ranging from 0 (not disabled) to 3 (severely disabled). As a result of the ordinal character of the rating, statistical and mathematical manipulations of the scores are complicated. The aim of this study was to obtain more insight in the dimensionality and hierarchical structure of the items, to overcome problems in comparing disability between items, between patients, and within patients between different moments in time. Mokken scale analysis of the disability scores from 1,967 rehabilitation inpatients showed that the 28 items constitute hierarchical scales. However, categorization of the items into the 5 original domains was not replicated. Five other scales or dimensions were investigated, measuring the level of extended ADL, extended psychological, fine motoric, work/leisure, and hearing/seeing activity, respectively. The number of items per dimension ranges from 14 in the extended ADL dimension to 2 each in the work/leisure and hearing/seeing dimensions. Although each disability item may be of importance in clinical case management, a reduced set of extended ADL items suffices to describe the disability level in this dimension for epidemiological research purposes. The other dimensions need further specification to provide reliable and sensitive measuring of disability. PMID:8540793

  18. 基于分级存储环境的数据即时应用产品%Real-Time Data Application Product Based on Hierarchical Storage Environment

    Institute of Scientific and Technical Information of China (English)

    何翔; 张明明; 黄高攀

    2016-01-01

    Currently, many large corporations adopt secondary deployment pattern in their core business. However, when head office analyzes the company-wide data timely and fully in this model, it may cause problems of large amount of data, scattered data storage, not timely responding to the changes in requirements and handiwork statistics. In this paper, based on the above problems, a multidimensional data analysis technology and software tool which can support the end users on-demand self-service data analysis are proposed. The software can analyze data according to different requirements of users, form a data view quickly, and show data through report forms finally. Furthermore, this flexible, efficient, practical and real-time data analysis tool has been successfully applied to State Grid Corporation of China (SGCC), which shows that it has some value in theory and practical applications.%目前很多大型企业的核心业务采用二级部署模式,此模式下总部对全公司范围内业务数据进行全面即时统计分析时会存在数据量大、存储分散、需求变化响应不及时以及手工统计填报等问题.基于以上问题,设计了一种基于分级存储环境的多维数据分析软件.该产品能够让用户从不同视角分析业务数据,快速形成满足业务工作需要的数据视图,最后通过报表的形式进行展示.该产品已成功应用于国家电网公司,具有一定的经济效益和理论价值.

  19. Hierarchical self-organization of non-cooperating individuals

    CERN Document Server

    Nepusz, Tamás

    2013-01-01

    Hierarchy is one of the most conspicuous features of numerous natural, technological and social systems. The underlying structures are typically complex and their most relevant organizational principle is the ordering of the ties among the units they are made of according to a network displaying hierarchical features. In spite of the abundant presence of hierarchy no quantitative theoretical interpretation of the origins of a multi-level, knowledge-based social network exists. Here we introduce an approach which is capable of reproducing the emergence of a multi-levelled network structure based on the plausible assumption that the individuals (representing the nodes of the network) can make the right estimate about the state of their changing environment to a varying degree. Our model accounts for a fundamental feature of knowledge-based organizations: the less capable individuals tend to follow those who are better at solving the problems they all face. We find that relatively simple rules lead to hierarchic...

  20. Core Recursive Hierarchical Image Segmentation

    Science.gov (United States)

    Tilton, James

    2011-01-01

    The Recursive Hierarchical Image Segmentation (RHSEG) software has been repackaged to provide a version of the RHSEG software that is not subject to patent restrictions and that can be released to the general public through NASA GSFC's Open Source release process. Like the Core HSEG Software Package, this Core RHSEG Software Package also includes a visualization program called HSEGViewer along with a utility program HSEGReader. It also includes an additional utility program called HSEGExtract. The unique feature of the Core RHSEG package is that it is a repackaging of the RHSEG technology designed to specifically avoid the inclusion of the certain software technology. Unlike the Core HSEG package, it includes the recursive portions of the technology, but does not include processing window artifact elimination technology.

  1. Groups possessing extensive hierarchical decompositions

    CERN Document Server

    Januszkiewicz, T; Leary, I J

    2009-01-01

    Kropholler's class of groups is the smallest class of groups which contains all finite groups and is closed under the following operator: whenever $G$ admits a finite-dimensional contractible $G$-CW-complex in which all stabilizer groups are in the class, then $G$ is itself in the class. Kropholler's class admits a hierarchical structure, i.e., a natural filtration indexed by the ordinals. For example, stage 0 of the hierarchy is the class of all finite groups, and stage 1 contains all groups of finite virtual cohomological dimension. We show that for each countable ordinal $\\alpha$, there is a countable group that is in Kropholler's class which does not appear until the $\\alpha+1$st stage of the hierarchy. Previously this was known only for $\\alpha= 0$, 1 and 2. The groups that we construct contain torsion. We also review the construction of a torsion-free group that lies in the third stage of the hierarchy.

  2. Hierarchical condensation near phase equilibrium

    Science.gov (United States)

    Olemskoi, A. I.; Yushchenko, O. V.; Borisyuk, V. N.; Zhilenko, T. I.; Kosminska, Yu. O.; Perekrestov, V. I.

    2012-06-01

    A novel mechanism of new phase formation is studied both experimentally and theoretically in the example of quasi-equilibrium stationary condensation in an ion-plasma sputterer. Copper condensates are obtained to demonstrate that a specific network structure is formed as a result of self-assembly in the course of deposition. The fractal pattern related is inherent in the phenomena of diffusion limited aggregation. Condensate nuclei are shown to form statistical ensemble of hierarchically subordinated objects distributed in ultrametric space. The Langevin equation and the Fokker-Planck equation related are found to describe stationary distribution of thermodynamic potential variations at condensation. Time dependence of the formation probability of branching structures is found to clarify the experimental situation.

  3. 基于层次分析涉密信息系统风险评估%Classified Information System Security Risk Assessment based on Hierarchical Analysis

    Institute of Scientific and Technical Information of China (English)

    李增鹏; 马春光; 李迎涛

    2014-01-01

    信息技术的发展使得政府和军队相关部门对信息系统安全问题提出更高要求。涉密信息系统安全有其独特性,风险评估区别于普通信息安全系统。文章以涉密信息系统为研究对象,首先阐述涉密信息系统的特点,针对其独特性对现有信息安全风险评估方法进行分析评价。然后将基于层析分析法的评估模型引入到涉密信息系统安全风险评估中。为涉密信息系统进行风险评估提供一种新的技术思路。最后通过实例分析,所提模型在处理涉密信息系统评估过程中对得到的离散数据分布无要求,与德菲尔法以及 BP 神经网络相比,该模型具有一定实用性和可扩张性,适合用于实际地涉密信息系统风险评估中。%The development of information technology makes the government and military authorities put forward higher requirements on the security of information system. The uniqueness of classified information system security makes risk assessment different from the common information security system. In this paper, classified information systems are research object. We first describe the characteristics of information system security, the uniqueness of the existing methods of analysis and evaluation of information security risk assessment. Then an evaluation model based on AHP is introduced into security risk assessment of information system security. A new way of classified information system risk assessment is presented. At last, through the analysis of an example, we analyze that the proposed model in processing of information system security evaluation process to get the discrete data distribution is not required, compared with the Delphi method and BP neural network, this model is highly of practicability and expansibility, it does suitable for classified information system risk assessment actually.

  4. 学生学校适应性影响因素的多层线性分析%The Factors Influencing Students' School Adjustment: Based on Analysis of Hierarchical Liner Modeling

    Institute of Scientific and Technical Information of China (English)

    赵必华

    2012-01-01

    问卷调查安徽省53所学校校长、4 010名初三学生,运用两水平多层线性模型,探查影响学生学校适应性的因素。研究发现:(1)学生学校适应性校际差别不大。(2)在学生个体层面,兄弟姐妹数量越少、家长学习期望越大、家长学习参与越多、个体知觉的同学关系与师生关系越积极,学生学校适应性就越好。(3)在学校层面,未发现有影响学生学校适应性的因素。%This research based on the result of a questionnaire of 53 headmasters from different middle-schools and 4010 students of grade 9, and used an analysis of Hierarchical Liner Modeling in two levels to explore the factors that impact students' school adjustment. The results showed that: (1) The Difference among schools in students' school adjustment is not very large ; (2) at the individual level, the fewer children the family, the bigger parents leaning expectations, the more parents'leaning participation, the more positive relationship between teachers and students, the more positive relationship between students, the more positive the students' school adjustment; (3) at the school level, there are no factors that influence students' school adjustment.

  5. A mechanical model of biomimetic adhesive pads with tilted and hierarchical structures

    Energy Technology Data Exchange (ETDEWEB)

    Schargott, M [Institute of Mechanics, Technische Universitaet Berlin, Strd 17 Juni 135, 10623 Berlin (Germany)], E-mail: martin.schargott@tu-berlin.de

    2009-06-01

    A 3D model for hierarchical biomimetic adhesive pads is constructed. It is based on the main principles of the adhesive pads of the Tokay gecko and consists of hierarchical layers of vertical or tilted beams, where each layer is constructed in such a way that no cohesion between adjacent beams can occur. The elastic and adhesive properties are calculated analytically and numerically. For the adhesive contact on stochastically rough surfaces, the maximum adhesion force increases with increasing number of hierarchical layers. Additional calculations show that the adhesion force also depends on the height spectrum of the rough surface.

  6. Generic Approach for Hierarchical Modulation Performance Analysis: Application to DVB-SH

    CERN Document Server

    Méric, Hugo; Amiot-Bazile, Caroline; Arnal, Fabrice; Boucheret, Marie-Laure

    2011-01-01

    Broadcasting systems have to deal with channel diversity in order to offer the best rate to the users. Hierarchical modulation is a practical solution to provide several rates in function of the channel quality. Unfortunately the performance evaluation of such modulations requires time consuming simulations. We propose in this paper a novel approach based on the channel capacity to avoid these simulations. The method allows to study the performance in terms of spectrum efficiency of hierarchical and also classical modulations combined with error correcting codes. Our method will be applied to the DVB-SH standard which considers hierarchical modulation as an optional feature.

  7. Anti-hierarchical evolution of the AGN space density in a hierarchical universe

    CERN Document Server

    Enoki, Motohiro; Kobayashi, Masakazu A R; Nagashima, Masahiro

    2014-01-01

    Recent observations show that the space density of luminous active galactic nuclei (AGN) peaks at higher redshifts than that of faint AGN. This downsizing trend in the AGN evolution seems to be contradictory to the hierarchical structure formation scenario. In this study, we present the AGN space density evolution predicted by a semi-analytic model of galaxy and AGN formation based on the hierarchical structure formation scenario. We demonstrate that our model can reproduce the downsizing trend of the AGN space density evolution. The reason for the downsizing trend in our model is a combination of the cold gas depletion as a consequence of star formation, the gas cooling suppression in massive halos and the AGN life time scaling with the dynamical time scale. We assume that a major merger of galaxies causes a starburst, spheroid formation, and cold gas accretion onto a supermassive black hole (SMBH). We also assume that this cold gas accretion triggers AGN activity. Since the cold gas is mainly depleted by st...

  8. Hierarchical modeling and analysis for spatial data

    CERN Document Server

    Banerjee, Sudipto; Gelfand, Alan E

    2003-01-01

    Among the many uses of hierarchical modeling, their application to the statistical analysis of spatial and spatio-temporal data from areas such as epidemiology And environmental science has proven particularly fruitful. Yet to date, the few books that address the subject have been either too narrowly focused on specific aspects of spatial analysis, or written at a level often inaccessible to those lacking a strong background in mathematical statistics.Hierarchical Modeling and Analysis for Spatial Data is the first accessible, self-contained treatment of hierarchical methods, modeling, and dat

  9. Ultrametric watersheds: a bijection theorem for hierarchical edge-segmentation

    CERN Document Server

    Najman, Laurent

    2010-01-01

    We study hierachical segmentation in the framework of edge-weighted graphs. We define ultrametric watersheds as topological watersheds null on the minima. We prove that there exists a bijection between the set of ultrametric watersheds and the set of hierarchical edgesegmentations. We end this paper by showing how the proposed framework allows to see constrained connectivity as a classical watershed-based morphological scheme, which provides an efficient algorithm to compute the whole hierarchy.

  10. Hierarchical Deep Learning Architecture For 10K Objects Classification

    OpenAIRE

    Atul Laxman Katole; Krishna Prasad Yellapragada; Amish Kumar Bedi; Sehaj Singh Kalra; Mynepalli Siva Chaitanya

    2015-01-01

    Evolution of visual object recognition architectures based on Convolutional Neural Networks & Convolutional Deep Belief Networks paradigms has revolutionized artificial Vision Science. These architectures extract & learn the real world hierarchical visual features utilizing supervised & unsupervised learning approaches respectively. Both the approaches yet cannot scale up realistically to provide recognition for a very large number of objects as high as 10K. We propose a two le...

  11. Behaviour design in microrobots: hierarchical reinforcement learning under resource constraints

    OpenAIRE

    Asadpour, Masoud

    2006-01-01

    In order to verify models of collective behaviors of animals, robots could be manipulated to implement the model and interact with real animals in a mixed-society. This thesis describes design of the behavioral hierarchy of a miniature robot, that is able to interact with cockroaches, and participates in their collective decision makings. The robots are controlled via a hierarchical behavior-based controller in which, more complex behaviors are built by combining simpler behaviors through fus...

  12. Behaviour design in microrobots: hierarchical reinforcement learning under resource constraints

    OpenAIRE

    Asadpour, Masoud; Siegwart, Roland

    2007-01-01

    In order to verify models of collective behaviors of animals, robots could be manipulated to implement the model and interact with real animals in a mixed-society. This thesis describes design of the behavioral hierarchy of a miniature robot, that is able to interact with cockroaches, and participates in their collective decision makings. The robots are controlled via a hierarchical behavior-based controller in which, more complex behaviors are built by combining simpler behaviors through fus...

  13. Hierarchical Bulk Synchronous Parallel Model and Performance Optimization

    Institute of Scientific and Technical Information of China (English)

    HUANG Linpeng; SUNYongqiang; YUAN Wei

    1999-01-01

    Based on the framework of BSP, aHierarchical Bulk Synchronous Parallel (HBSP) performance model isintroduced in this paper to capture the performance optimizationproblem for various stages in parallel program development and toaccurately predict the performance of a parallel program byconsidering factors causing variance at local computation and globalcommunication. The related methodology has been applied to several realapplications and the results show that HBSP is a suitable model foroptimizing parallel programs.

  14. Improving MPI support for applications on hierarchically distributed resources

    OpenAIRE

    Lanteri, Stephane; López Lozano, Raúl; Pérez, Christian

    2007-01-01

    Programming non-embarrassingly parallel scientific computing applications such as those involving the numerical resolution of system of PDEs using mesh based methods for grid computing environments is a complex and important issue. This work contributes to this goal by proposing some MPI extensions to let programmers deal with the hierarchical nature of the grid infrastructure thanks to a tree representation of the processes as well as the corresponding extension of collective and point-to-po...

  15. Hierarchical Composites to Reduce N-Nitrosamines in Cigarette Smoke

    Directory of Open Access Journals (Sweden)

    Yan Yan Li

    2015-03-01

    Full Text Available In order to reduce the harmful constituents in cigarette smoke, two hierarchical composites were synthesized. Based on, zeolites HZSM-5 or NaY fragments were introduced into the synthetic system of mesoporous silica SBA-15 or MCM-41 and assembled with the mesoporous materials. These porous composites combine the advantages of micro- and mesoporous materials, and exhibit higher effects than activated carbon on reducing tobacco specific nitrosamines (TSNA and some vapor phase compounds in smoke.

  16. Configuration performance predication method of product family based on hierarchical support vector machine%基于递阶支持向量机的产品族配置性能预测

    Institute of Scientific and Technical Information of China (English)

    崔文华; 刘晓冰; 王伟; 王介生

    2013-01-01

    To predict the configuration performances of modular product family design accurately and quickly for judging whether to meet the diverse customer demand,a configuration performance prediction method of modular product family based on Hierarchical Support Vector Machine (H-SVM) was proposed.The new variant product performances were predicted through the data mining on the history database of typical product in the product family.The framework and basic procedure of configuration comprehensive performance prediction method based on H-SVM was introduced.An improved Shuffled Frog Leaping Algorithm (SFLA) was adopted to optimize the kernel function parameters and error penalty factors of SVM models,where the simulated annealing algorithm was used to increase local searching ability and convergence velocity.The method was verified on a developed modular paper currency sorter product family to assess the effectiveness of the proposed method.%为了准确而快速地对模块化产品族的配置性能进行预测,以判断其是否满足多样化的客户需求,提出了基于递阶支持向量机的模块化产品族配置性能预测方法.新配置产品性能通过对产品族中的典型产品历史数据库进行数据挖掘进行预测.介绍了基于递阶支持向量机的配置综合性能预测方法的预测框架和基本步骤,并提出一种改进混合蛙跳算法来优化支持向量化模型的核函数参数和误差惩罚因子,模拟退火算法用来提高算法的局部搜索能力和收敛速度.以某模块化设计的纸币清分机产品族为例,验证了所提评估策略的有效性.

  17. Hierarchical sliding mode control for under-actuated cranes design, analysis and simulation

    CERN Document Server

    Qian, Dianwei

    2015-01-01

    This book reports on the latest developments in sliding mode overhead crane control, presenting novel research ideas and findings on sliding mode control (SMC), hierarchical SMC and compensator design-based hierarchical sliding mode. The results, which were previously scattered across various journals and conference proceedings, are now presented in a systematic and unified form. The book will be of interest to researchers, engineers and graduate students in control engineering and mechanical engineering who want to learn the methods and applications of SMC.

  18. COHeRE: Cross-Ontology Hierarchical Relation Examination for Ontology Quality Assurance

    OpenAIRE

    Cui, Licong

    2015-01-01

    Biomedical ontologies play a vital role in healthcare information management, data integration, and decision support. Ontology quality assurance (OQA) is an indispensable part of the ontology engineering cycle. Most existing OQA methods are based on the knowledge provided within the targeted ontology. This paper proposes a novel cross-ontology analysis method, Cross-Ontology Hierarchical Relation Examination (COHeRE), to detect inconsistencies and possible errors in hierarchical relations acr...

  19. Semi-supervised adaptive-height snipping of the hierarchical clustering tree

    OpenAIRE

    Obulkasim, Askar; Meijer, Gerrit A; van de Wiel, Mark A

    2015-01-01

    Background In genomics, hierarchical clustering (HC) is a popular method for grouping similar samples based on a distance measure. HC algorithms do not actually create clusters, but compute a hierarchical representation of the data set. Usually, a fixed height on the HC tree is used, and each contiguous branch of samples below that height is considered a separate cluster. Due to the fixed-height cutting, those clusters may not unravel significant functional coherence hidden deeper in the tree...

  20. Hierarchical Bayes Ensemble Kalman Filtering

    CERN Document Server

    Tsyrulnikov, Michael

    2015-01-01

    Ensemble Kalman filtering (EnKF), when applied to high-dimensional systems, suffers from an inevitably small affordable ensemble size, which results in poor estimates of the background error covariance matrix ${\\bf B}$. The common remedy is a kind of regularization, usually an ad-hoc spatial covariance localization (tapering) combined with artificial covariance inflation. Instead of using an ad-hoc regularization, we adopt the idea by Myrseth and Omre (2010) and explicitly admit that the ${\\bf B}$ matrix is unknown and random and estimate it along with the state (${\\bf x}$) in an optimal hierarchical Bayes analysis scheme. We separate forecast errors into predictability errors (i.e. forecast errors due to uncertainties in the initial data) and model errors (forecast errors due to imperfections in the forecast model) and include the two respective components ${\\bf P}$ and ${\\bf Q}$ of the ${\\bf B}$ matrix into the extended control vector $({\\bf x},{\\bf P},{\\bf Q})$. Similarly, we break the traditional backgrou...

  1. Image meshing via hierarchical optimization*

    Institute of Scientific and Technical Information of China (English)

    Hao XIE; Ruo-feng TONGS

    2016-01-01

    Vector graphic, as a kind of geometric representation of raster images, has many advantages, e.g., definition independence and editing facility. A popular way to convert raster images into vector graphics is image meshing, the aim of which is to find a mesh to represent an image as faithfully as possible. For traditional meshing algorithms, the crux of the problem resides mainly in the high non-linearity and non-smoothness of the objective, which makes it difficult to find a desirable optimal solution. To ameliorate this situation, we present a hierarchical optimization algorithm solving the problem from coarser levels to finer ones, providing initialization for each level with its coarser ascent. To further simplify the problem, the original non-convex problem is converted to a linear least squares one, and thus becomes convex, which makes the problem much easier to solve. A dictionary learning framework is used to combine geometry and topology elegantly. Then an alternating scheme is employed to solve both parts. Experiments show that our algorithm runs fast and achieves better results than existing ones for most images.

  2. Image meshing via hierarchical optimization

    Institute of Scientific and Technical Information of China (English)

    Hao XIE; Ruo-feng TONG‡

    2016-01-01

    Vector graphic, as a kind of geometric representation of raster images, has many advantages, e.g., defi nition independence and editing facility. A popular way to convert raster images into vector graphics is image meshing, the aim of which is to fi nd a mesh to represent an image as faithfully as possible. For traditional meshing algorithms, the crux of the problem resides mainly in the high non-linearity and non-smoothness of the objective, which makes it difficult to fi nd a desirable optimal solution. To ameliorate this situation, we present a hierarchical optimization algorithm solving the problem from coarser levels to fi ner ones, providing initialization for each level with its coarser ascent. To further simplify the problem, the original non-convex problem is converted to a linear least squares one, and thus becomes convex, which makes the problem much easier to solve. A dictionary learning framework is used to combine geometry and topology elegantly. Then an alternating scheme is employed to solve both parts. Experiments show that our algorithm runs fast and achieves better results than existing ones for most images.

  3. HIERARCHICAL ORGANIZATION OF INFORMATION, IN RELATIONAL DATABASES

    Directory of Open Access Journals (Sweden)

    Demian Horia

    2008-05-01

    Full Text Available In this paper I will present different types of representation, of hierarchical information inside a relational database. I also will compare them to find the best organization for specific scenarios.

  4. Hierarchical modularity in human brain functional networks

    CERN Document Server

    Meunier, D; Fornito, A; Ersche, K D; Bullmore, E T; 10.3389/neuro.11.037.2009

    2010-01-01

    The idea that complex systems have a hierarchical modular organization originates in the early 1960s and has recently attracted fresh support from quantitative studies of large scale, real-life networks. Here we investigate the hierarchical modular (or "modules-within-modules") decomposition of human brain functional networks, measured using functional magnetic resonance imaging (fMRI) in 18 healthy volunteers under no-task or resting conditions. We used a customized template to extract networks with more than 1800 regional nodes, and we applied a fast algorithm to identify nested modular structure at several hierarchical levels. We used mutual information, 0 < I < 1, to estimate the similarity of community structure of networks in different subjects, and to identify the individual network that is most representative of the group. Results show that human brain functional networks have a hierarchical modular organization with a fair degree of similarity between subjects, I=0.63. The largest 5 modules at ...

  5. Hierarchical DSE for multi-ASIP platforms

    DEFF Research Database (Denmark)

    Micconi, Laura; Corvino, Rosilde; Gangadharan, Deepak; Madsen, Jan; Pop, Paul; Jozwiak, Lech

    This work proposes a hierarchical Design Space Exploration (DSE) for the design of multi-processor platforms targeted to specific applications with strict timing and area constraints. In particular, it considers platforms integrating multiple Application Specific Instruction Set Processors (ASIPs...

  6. Ultrafast Hierarchical OTDM/WDM Network

    OpenAIRE

    Hideyuki Sotobayashi; Wataru Chujo; Takeshi Ozeki

    2003-01-01

    Ultrafast hierarchical OTDM/WDM network is proposed for the future core-network. We review its enabling technologies: C- and L-wavelength-band generation, OTDM-WDM mutual multiplexing format conversions, and ultrafast OTDM wavelengthband conversions.

  7. An Automatic Hierarchical Delay Analysis Tool

    Institute of Scientific and Technical Information of China (English)

    FaridMheir-El-Saadi; BozenaKaminska

    1994-01-01

    The performance analysis of VLSI integrated circuits(ICs) with flat tools is slow and even sometimes impossible to complete.Some hierarchical tools have been developed to speed up the analysis of these large ICs.However,these hierarchical tools suffer from a poor interaction with the CAD database and poorly automatized operations.We introduce a general hierarchical framework for performance analysis to solve these problems.The circuit analysis is automatic under the proposed framework.Information that has been automatically abstracted in the hierarchy is kept in database properties along with the topological information.A limited software implementation of the framework,PREDICT,has also been developed to analyze the delay performance.Experimental results show that hierarchical analysis CPU time and memory requirements are low if heuristics are used during the abstraction process.

  8. A Hierarchical Analysis of Environmental Attitudes.

    Science.gov (United States)

    Richmond, James M.; Baumgart, Neil

    1981-01-01

    Reported is a reanalysis of responses of a survey of environmental attitudes of English high school students. The purpose of the analysis was to try to determine if there was a hierarchical relationship among the items. Relationships were identified. (RH)

  9. Indexing hierarchical structures using graph spectra.

    Science.gov (United States)

    Shokoufandeh, Ali; Macrini, Diego; Dickinson, Sven; Siddiqi, Kaleem; Zucker, Steven W

    2005-07-01

    Hierarchical image structures are abundant in computer vision and have been used to encode part structure, scale spaces, and a variety of multiresolution features. In this paper, we describe a framework for indexing such representations that embeds the topological structure of a directed acyclic graph (DAG) into a low-dimensional vector space. Based on a novel spectral characterization of a DAG, this topological signature allows us to efficiently retrieve a promising set of candidates from a database of models using a simple nearest-neighbor search. We establish the insensitivity of the signature to minor perturbation of graph structure due to noise, occlusion, or node split/merge. To accommodate large-scale occlusion, the DAG rooted at each nonleaf node of the query "votes" for model objects that share that "part," effectively accumulating local evidence in a model DAG's topological subspaces. We demonstrate the approach with a series of indexing experiments in the domain of view-based 3D object recognition using shock graphs. PMID:16013759

  10. Dynamic hierarchical algorithm for accelerated microfossil identification

    Science.gov (United States)

    Wong, Cindy M.; Joseph, Dileepan

    2015-02-01

    Marine microfossils provide a useful record of the Earth's resources and prehistory via biostratigraphy. To study Hydrocarbon reservoirs and prehistoric climate, geoscientists visually identify the species of microfossils found in core samples. Because microfossil identification is labour intensive, automation has been investigated since the 1980s. With the initial rule-based systems, users still had to examine each specimen under a microscope. While artificial neural network systems showed more promise for reducing expert labour, they also did not displace manual identification for a variety of reasons, which we aim to overcome. In our human-based computation approach, the most difficult step, namely taxon identification is outsourced via a frontend website to human volunteers. A backend algorithm, called dynamic hierarchical identification, uses unsupervised, supervised, and dynamic learning to accelerate microfossil identification. Unsupervised learning clusters specimens so that volunteers need not identify every specimen during supervised learning. Dynamic learning means interim computation outputs prioritize subsequent human inputs. Using a dataset of microfossils identified by an expert, we evaluated correct and incorrect genus and species rates versus simulated time, where each specimen identification defines a moment. The proposed algorithm accelerated microfossil identification effectively, especially compared to benchmark results obtained using a k-nearest neighbour method.

  11. Hierarchical Nanopatterns for Cell Adhesion Studies

    OpenAIRE

    Schwieder, Marco

    2008-01-01

    Hierarchical nanopatterned interfaces are an intriguing tool to study clustering processes of proteins like for example integrins that mediate cell adhesion. The aim of this work is the development of innovative methods for the fabrication of hierarchical micro-nanopatterned surfaces and the use of such systems as platforms to study cell adhesion. In the first part of this work different approaches are presented which are suitable for preparing micro-nanopatterned interfaces at a large scale ...

  12. Hierarchical Control for Multiple DC Microgrids Clusters

    DEFF Research Database (Denmark)

    Shafiee, Qobad; Dragicevic, Tomislav; Vasquez, Juan Carlos;

    2014-01-01

    This paper presents a distributed hierarchical control framework to ensure reliable operation of dc Microgrid (MG) clusters. In this hierarchy, primary control is used to regulate the common bus voltage inside each MG locally. An adaptive droop method is proposed for this level which determines d...... with all the proposed control loops. The effectiveness of proposed hierarchical scheme is verified through detailed hardware-in-the-loop (HIL) simulations....

  13. Widening the Schedulability Hierarchical Scheduling Systems

    OpenAIRE

    Boudjadar, Jalil; David, Alexandre; Kim, Jin Hyun; Larsen, Kim Guldstrand; Mikučionis, Marius; Nyman, Ulrik; Skou, Arne

    2015-01-01

    This paper presents a compositional approach for schedula-bility analysis of hierarchical systems, which enables to prove more sys-tems schedulable by having richer and more detailed scheduling models.We use a lightweight method (statistical model checking) for design ex-ploration, easily assuring high confidence in the correctness of the model.A satisfactory design can be proved schedulable using the computationcostly method (symbolic model checking). In order to analyze a hierar-chical sche...

  14. Hierarchical organization versus self-organization

    OpenAIRE

    Busseniers, Evo

    2014-01-01

    In this paper we try to define the difference between hierarchical organization and self-organization. Organization is defined as a structure with a function. So we can define the difference between hierarchical organization and self-organization both on the structure as on the function. In the next two chapters these two definitions are given. For the structure we will use some existing definitions in graph theory, for the function we will use existing theory on (self-)organization. In the t...

  15. Hierarchical Modelling of Flood Risk for Engineering Decision Analysis

    DEFF Research Database (Denmark)

    Custer, Rocco

    Societies around the world are faced with flood risk, prompting authorities and decision makers to manage risk to protect population and assets. With climate change, urbanisation and population growth, flood risk changes constantly, requiring flood risk management strategies that are flexible and...... robust. Traditional risk management solutions, e.g. dike construction, are not particularly flexible, as they are difficult to adapt to changing risk. Conversely, the recent concept of integrated flood risk management, entailing a combination of several structural and non-structural risk management...... measures, allows identifying flexible and robust flood risk management strategies. Based on it, this thesis investigates hierarchical flood protection systems, which encompass two, or more, hierarchically integrated flood protection structures on different spatial scales (e.g. dikes, local flood barriers...

  16. Charged diphenylalanine nanotubes and controlled hierarchical self-assembly.

    Science.gov (United States)

    Wang, Minjie; Du, Lingjie; Wu, Xinglong; Xiong, Shijie; Chu, Paul K

    2011-06-28

    Hexagonal hierarchical microtubular structures are produced by diphenylalanine self-assembly and the ratio of the relative humidity in the growth chamber to the diphenylalanine concentration (defined as the RH-FF ratio) determines the microtubular morphology. The hexagonal arrangement of the diphenylalanine molecules first induces the hexagonal nanotubes with opposite charges on the two ends, and the dipolar electric field on the nanotubes serves as the driving force. Side-by-side hexagonal aggregation and end-to-end arrangement ensue finally producing a hexagonal hierarchical microtubular structure. Staining experiments and the external electric field-induced parallel arrangement provide evidence of the existence of opposite charges and dipolar electric field. In this self-assembly, the different RH-FF ratios induce different contents of crystalline phases. This leads to different initial nanotube numbers finally yielding different microtubular morphologies. Our calculation based on the dipole model supports the dipole-field mechanism that leads to the different microtubular morphologies. PMID:21591732

  17. Nonlinear robust hierarchical control for nonlinear uncertain systems

    Directory of Open Access Journals (Sweden)

    Leonessa Alexander

    1999-01-01

    Full Text Available A nonlinear robust control-system design framework predicated on a hierarchical switching controller architecture parameterized over a set of moving nominal system equilibria is developed. Specifically, using equilibria-dependent Lyapunov functions, a hierarchical nonlinear robust control strategy is developed that robustly stabilizes a given nonlinear system over a prescribed range of system uncertainty by robustly stabilizing a collection of nonlinear controlled uncertain subsystems. The robust switching nonlinear controller architecture is designed based on a generalized (lower semicontinuous Lyapunov function obtained by minimizing a potential function over a given switching set induced by the parameterized nominal system equilibria. The proposed framework robustly stabilizes a compact positively invariant set of a given nonlinear uncertain dynamical system with structured parametric uncertainty. Finally, the efficacy of the proposed approach is demonstrated on a jet engine propulsion control problem with uncertain pressure-flow map data.

  18. Malic acid assisted precursor route to hierarchical structured nickel oxide

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haizhen [Zhejiang California International Nanosystems Institute, Zhejiang University, Hangzhou, Zhejiang (China); Qian, Yitai [Hefei National Laboratory for Physical Science at Microscale, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui (China)

    2010-05-15

    A novel malic acid assisted precursor route to prepare NiO materials with novel hierarchical structures has been investigated in this work. The Ni-based precursors can be synthesized by a malic acid-assisted hydrothermal route, which have been characterized by powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA). NiO materials can be prepared via the thermal treatment of the precursor in ambient atmosphere. The XRD, SEM, Energy dispersive X-ray spectroscopy (EDS) and UV-Vis spectroscopy of the NiO materials were also examined. The effects of the reaction conditions, such as the reaction temperature, the quantity of the raw materials on the morphologies of the precursors were discussed, which indicates that it is an effective method to synthesize NiO materials with different hierarchical structures. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Hierarchical fuzzy control of low-energy building systems

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zhen; Dexter, Arthur [Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ (United Kingdom)

    2010-04-15

    A hierarchical fuzzy supervisory controller is described that is capable of optimizing the operation of a low-energy building, which uses solar energy to heat and cool its interior spaces. The highest level fuzzy rules choose the most appropriate set of lower level rules according to the weather and occupancy information; the second level fuzzy rules determine an optimal energy profile and the overall modes of operation of the heating, ventilating and air-conditioning system (HVAC); the third level fuzzy rules select the mode of operation of specific equipment, and assign schedules to the local controllers so that the optimal energy profile can be achieved in the most efficient way. Computer simulation is used to compare the hierarchical fuzzy control scheme with a supervisory control scheme based on expert rules. The performance is evaluated by comparing the energy consumption and thermal comfort. (author)

  20. Multi-level Hierarchical Poly Tree computer architectures

    Science.gov (United States)

    Padovan, Joe; Gute, Doug

    1990-01-01

    Based on the concept of hierarchical substructuring, this paper develops an optimal multi-level Hierarchical Poly Tree (HPT) parallel computer architecture scheme which is applicable to the solution of finite element and difference simulations. Emphasis is given to minimizing computational effort, in-core/out-of-core memory requirements, and the data transfer between processors. In addition, a simplified communications network that reduces the number of I/O channels between processors is presented. HPT configurations that yield optimal superlinearities are also demonstrated. Moreover, to generalize the scope of applicability, special attention is given to developing: (1) multi-level reduction trees which provide an orderly/optimal procedure by which model densification/simplification can be achieved, as well as (2) methodologies enabling processor grading that yields architectures with varying types of multi-level granularity.

  1. Hierarchical Nanoceramics for Industrial Process Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Ruud, James, A.; Brosnan, Kristen, H.; Striker, Todd; Ramaswamy, Vidya; Aceto, Steven, C.; Gao, Yan; Willson, Patrick, D.; Manoharan, Mohan; Armstrong, Eric, N., Wachsman, Eric, D.; Kao, Chi-Chang

    2011-07-15

    This project developed a robust, tunable, hierarchical nanoceramics materials platform for industrial process sensors in harsh-environments. Control of material structure at multiple length scales from nano to macro increased the sensing response of the materials to combustion gases. These materials operated at relatively high temperatures, enabling detection close to the source of combustion. It is anticipated that these materials can form the basis for a new class of sensors enabling widespread use of efficient combustion processes with closed loop feedback control in the energy-intensive industries. The first phase of the project focused on materials selection and process development, leading to hierarchical nanoceramics that were evaluated for sensing performance. The second phase focused on optimizing the materials processes and microstructures, followed by validation of performance of a prototype sensor in a laboratory combustion environment. The objectives of this project were achieved by: (1) synthesizing and optimizing hierarchical nanostructures; (2) synthesizing and optimizing sensing nanomaterials; (3) integrating sensing functionality into hierarchical nanostructures; (4) demonstrating material performance in a sensing element; and (5) validating material performance in a simulated service environment. The project developed hierarchical nanoceramic electrodes for mixed potential zirconia gas sensors with increased surface area and demonstrated tailored electrocatalytic activity operable at high temperatures enabling detection of products of combustion such as NOx close to the source of combustion. Methods were developed for synthesis of hierarchical nanostructures with high, stable surface area, integrated catalytic functionality within the structures for gas sensing, and demonstrated materials performance in harsh lab and combustion gas environments.

  2. Bayesian hierarchical grouping: Perceptual grouping as mixture estimation.

    Science.gov (United States)

    Froyen, Vicky; Feldman, Jacob; Singh, Manish

    2015-10-01

    We propose a novel framework for perceptual grouping based on the idea of mixture models, called Bayesian hierarchical grouping (BHG). In BHG, we assume that the configuration of image elements is generated by a mixture of distinct objects, each of which generates image elements according to some generative assumptions. Grouping, in this framework, means estimating the number and the parameters of the mixture components that generated the image, including estimating which image elements are "owned" by which objects. We present a tractable implementation of the framework, based on the hierarchical clustering approach of Heller and Ghahramani (2005). We illustrate it with examples drawn from a number of classical perceptual grouping problems, including dot clustering, contour integration, and part decomposition. Our approach yields an intuitive hierarchical representation of image elements, giving an explicit decomposition of the image into mixture components, along with estimates of the probability of various candidate decompositions. We show that BHG accounts well for a diverse range of empirical data drawn from the literature. Because BHG provides a principled quantification of the plausibility of grouping interpretations over a wide range of grouping problems, we argue that it provides an appealing unifying account of the elusive Gestalt notion of Prägnanz. PMID:26322548

  3. A hierarchical model for spatial capture-recapture data

    Science.gov (United States)

    Royle, J. Andrew; Young, K.V.

    2008-01-01

    Estimating density is a fundamental objective of many animal population studies. Application of methods for estimating population size from ostensibly closed populations is widespread, but ineffective for estimating absolute density because most populations are subject to short-term movements or so-called temporary emigration. This phenomenon invalidates the resulting estimates because the effective sample area is unknown. A number of methods involving the adjustment of estimates based on heuristic considerations are in widespread use. In this paper, a hierarchical model of spatially indexed capture recapture data is proposed for sampling based on area searches of spatial sample units subject to uniform sampling intensity. The hierarchical model contains explicit models for the distribution of individuals and their movements, in addition to an observation model that is conditional on the location of individuals during sampling. Bayesian analysis of the hierarchical model is achieved by the use of data augmentation, which allows for a straightforward implementation in the freely available software WinBUGS. We present results of a simulation study that was carried out to evaluate the operating characteristics of the Bayesian estimator under variable densities and movement patterns of individuals. An application of the model is presented for survey data on the flat-tailed horned lizard (Phrynosoma mcallii) in Arizona, USA.

  4. Growth Mechanism of Pumpkin-Shaped Vaterite Hierarchical Structures

    Science.gov (United States)

    Ma, Guobin; Xu, Yifei; Wang, Mu

    2015-03-01

    CaCO3-based biominerals possess sophisticated hierarchical structures and promising mechanical properties. Recent researches imply that vaterite may play an important role in formation of CaCO3-based biominerals. However, as a less common polymorph of CaCO3, the growth mechanism of vaterite remains not very clear. Here we report the growth of a pumpkin-shaped vaterite hierarchical structure with a six-fold symmetrical axis and lamellar microstructure. We demonstrate that the growth is controlled by supersaturation and the intrinsic crystallographic anisotropy of vaterite. For the scenario of high supersaturation, the nucleation rate is higher than the lateral extension rate, favoring the ``double-leaf'' spherulitic growth. Meanwhile, nucleation occurs preferentially in as determined by the crystalline structure of vaterite, modulating the grown products with a hexagonal symmetry. The results are beneficial for an in-depth understanding of the biomineralization of CaCO3. The growth mechanism may also be applicable to interpret the formation of similar hierarchical structures of other materials. The authors gratefully acknowledge the financial support from National Science Foundation of China (Grant Nos. 51172104 and 50972057) and National Key Basic Research Program of China (Grant No. 2010CB630705).

  5. Technology and application of hierarchical process maturity modeling based on IDEF%基于IDEF的分层递阶工艺成熟度建模技术及应用

    Institute of Scientific and Technical Information of China (English)

    伍晓榕; 张树有; 裘乐淼; 孙良峰

    2013-01-01

    According to the parallelism of product design and process planning in product development process and the regular pattern from roughness to precision of product design information,the product design process was divided into conceptual process,rough process,detail process and modified process of four job levels.Each level's main process activities were modeled by Integrated Computer Aided Manufacturing DEFinition method (IDEF),and the hierarchical process maturity model of four levels was constructed.Aiming at the information coarseness of conceptual process layer,the maturity evaluation based on product characteristic was proposed.For the information fineness of process improvement layer,the process maturity was evaluated by process failure knowledge.The proposed model was verified in an intelligent computer aided process planning system for automobile parts manufacture,and the result showed that it was helped to forward the process design stage and improve the manufacture reliability.%根据产品开发过程中存在的产品设计和工艺设计并行性,以及产品设计信息由粗渐细的递进规律,将产品工艺设计过程划分为概要工艺层、初步工艺层、详细工艺层和改进工艺层.利用集成定义建模理论对各层主要工艺活动进行建模,构建出四梯级的分层递阶工艺成熟度模型.针对概要工艺层的信息粗粒度,提出基于主要产品特征的成熟度评估,而对于信息细粒度的工艺改进层,则采用工艺失效知识进行工艺成熟度评估.所提方法在某汽车零配件产品工艺设计中得到应用验证,有助于工艺设计阶段的前移和制造可靠性的提高.

  6. 基于拓扑分层的配电网电气接线图自动生成算法%An Automatic Electrical Diagram Generation Method for Distribution Networks Based on Hierarchical Topology Model

    Institute of Scientific and Technical Information of China (English)

    廖凡钦; 刘东; 闫红漫; 于文鹏; 黄玉辉; 万顷波

    2014-01-01

    The automatic generation of the electrical diagram for a distribution network is a complex optimization problem.The nature of this process is to determine the relative positions of equipment of the distribution network in a 2-D plane.Based on a simplified hierarchical model,an automatic drawing algorithm is proposed to automatically generate the electrical diagram.The algorithm solves this problem by decomposing it into three steps,namely,preliminary layout,framework routing and complete drawing.The preliminary layout is obtained with gravitation-repulsion model.The power station drawing is completed through equipment classification and comparison of each outlet line”s dip angle.The routing priority is used to ensure there is no overlapping and crossing of routing.The overall automatic generation of the electrical diagram can then be obtained with respect to its original integrated topology structure.Finally,a practical case study of a city”s distribution network is given to show the effectiveness of the method and the automatic layout algorithm.%配电网电气接线图的自动生成是一个复杂的优化问题,其本质是在一个平面合理确定配电网拓扑中各设备间的相对坐标位置。文中提出一种基于拓扑分层的成图算法,该算法首先在原拓扑模型基础上构建3层不同程度简化的分层成图拓扑模型,在此基础上对应地将自动成图问题分解为初步布局、骨架布线和完整绘图这3个步骤求解。采用基于引力-斥力模型的布局算法完成初步布局,通过设备分类和比较电站出线的倾角大小实现电站成图,采用基于区分布线优先顺序的算法完成主干线的无重叠交叉布线,最终生成与原拓扑结构完全对应的配电网电气接线图。针对某市配电网的实例成图表明了所提算法的有效性。

  7. SafeZone: A Hierarchical Inter-Domain Authenticated Source Address Validation Solution

    CERN Document Server

    Li, Jie; Xu, Ke

    2011-01-01

    Next generation Internet is highly concerned about the issue of reliability. Principally, the foundation of reliability is authentication of the source IP address. With the signature-and-verification based defense mechanisms available today, unfortunately, there is a lack of hierarchical architecture, which makes the structure of the trust alliance excessively flat and single. Moreover, with the increasing scale of the trust alliance, costs of validation grow so quickly that they do not adapt to incremental deployment. Via comparison with traditional solutions, this article proposes a hierarchical, inter-domain authenticated source address validation solution named SafeZone. SafeZone employs two intelligent designs, lightweight tag replacement and a hierarchical partitioning scheme, each of which helps to ensure that SafeZone can construct trustworthy and hierarchical trust alliances without the negative influences and complex operations on de facto networks. Extensive experiments also indicate that SafeZone ...

  8. ZnO hierarchical nanostructures and application on high-efficiency dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Fu Yingsong [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); MFAL-TJ, Motorola (China) Electronics Ltd, Tianjin 300457 (China); Sun Jing; Xie Yang [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Liu, Jim [MFAL-TJ, Motorola (China) Electronics Ltd, Tianjin 300457 (China); Wang Hongli [School of Mechanical Engineering, Tianjin University, Tianjin 300072 (China); Du Xiwen, E-mail: xwdu@tju.edu.c [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)

    2010-02-15

    Uniform hierarchical ZnO nanostructures are synthesized on a large scale based on a solution approach at low temperature. The primary ZnO hexagonal prisms are firstly produced by the reaction of Zn(NO{sub 3}){sub 2} with hexamethylenetetramine, and then ZnO branches grow on the primary prisms by using ethylenediamine molecules as an evocator. The morphology of the hierarchical nanostructure can be controlled conveniently by adjusting the molar ratio of [EDA]/[Zn{sup 2+}]. The hierarchical structure provides an effective pathway for carrier transport as well as larger surface area for dye adsorption, when ZnO hierarchical nanostructures serve as photoanode materials, the solar cells show higher conversion efficiency than that of primary ZnO nanowires.

  9. On the Hierarchical Preconditioning of the PMCHWT Integral Equation on Simply and Multiply Connected Geometries

    CERN Document Server

    Guzman, J E Ortiz; Mitharwal, R; Beghein, Y; Eibert, T F; Cools, K; Andriulli, F P

    2016-01-01

    We present a hierarchical basis preconditioning strategy for the Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) integral equation considering both simply and multiply connected geometries.To this end, we first consider the direct application of hierarchical basis preconditioners, developed for the Electric Field Integral Equation (EFIE), to the PMCHWT. It is notably found that, whereas for the EFIE a diagonal preconditioner can be used for obtaining the hierarchical basis scaling factors, this strategy is catastrophic in the case of the PMCHWT since it leads to a severly ill-conditioned PMCHWT system in the case of multiply connected geometries. We then proceed to a theoretical analysis of the effect of hierarchical bases on the PMCHWT operator for which we obtain the correct scaling factors and a provably effective preconditioner for both low frequencies and mesh refinements. Numerical results will corroborate the theory and show the effectiveness of our approach.

  10. Hierarchically engineered fibrous scaffolds for bone regeneration

    Science.gov (United States)

    Sachot, Nadège; Castaño, Oscar; Mateos-Timoneda, Miguel A.; Engel, Elisabeth; Planell, Josep A.

    2013-01-01

    Surface properties of biomaterials play a major role in the governing of cell functionalities. It is well known that mechanical, chemical and nanotopographic cues, for example, influence cell proliferation and differentiation. Here, we present a novel coating protocol to produce hierarchically engineered fibrous scaffolds with tailorable surface characteristics, which mimic bone extracellular matrix. Based on the sol–gel method and a succession of surface treatments, hollow electrospun polylactic acid fibres were coated with a silicon–calcium–phosphate bioactive organic–inorganic glass. Compared with pure polymeric fibres that showed a completely smooth surface, the coated fibres exhibited a nanostructured topography and greater roughness. They also showed improved hydrophilic properties and a Young's modulus sixfold higher than non-coated ones, while remaining fully flexible and easy to handle. Rat mesenchymal stem cells cultured on these fibres showed great cellular spreading and interactions with the material. This protocol can be transferred to other structures and glasses, allowing the fabrication of various materials with well-defined features. This novel approach represents therefore a valuable improvement in the production of artificial matrices able to direct stem cell fate through physical and chemical interactions. PMID:23985738

  11. Automatic Construction of Hierarchical Road Networks

    Science.gov (United States)

    Yang, Weiping

    2016-06-01

    This paper describes an automated method of constructing a hierarchical road network given a single dataset, without the presence of thematic attributes. The method is based on a pattern graph which maintains nodes and paths as junctions and through-traffic roads. The hierarchy is formed incrementally in a top-down fashion for highways, ramps, and major roads directly connected to ramps; and bottom-up for the rest of major and minor roads. Through reasoning and analysis, ramps are identified as unique characteristics for recognizing and assembling high speed roads. The method makes distinctions on the types of ramps by articulating their connection patterns with highways. Major and minor roads will be identified by both quantitative and qualitative analysis of spatial properties and by discovering neighbourhood patterns revealed in the data. The result of the method would enrich data description and support comprehensive queries on sorted exit or entry points on highways and their related roads. The enrichment on road network data is important to a high successful rate of feature matching for road networks and to geospatial data integration.

  12. Improved gravitation field algorithm and its application in hierarchical clustering.

    Directory of Open Access Journals (Sweden)

    Ming Zheng

    Full Text Available BACKGROUND: Gravitation field algorithm (GFA is a new optimization algorithm which is based on an imitation of natural phenomena. GFA can do well both for searching global minimum and multi-minima in computational biology. But GFA needs to be improved for increasing efficiency, and modified for applying to some discrete data problems in system biology. METHOD: An improved GFA called IGFA was proposed in this paper. Two parts were improved in IGFA. The first one is the rule of random division, which is a reasonable strategy and makes running time shorter. The other one is rotation factor, which can improve the accuracy of IGFA. And to apply IGFA to the hierarchical clustering, the initial part and the movement operator were modified. RESULTS: Two kinds of experiments were used to test IGFA. And IGFA was applied to hierarchical clustering. The global minimum experiment was used with IGFA, GFA, GA (genetic algorithm and SA (simulated annealing. Multi-minima experiment was used with IGFA and GFA. The two experiments results were compared with each other and proved the efficiency of IGFA. IGFA is better than GFA both in accuracy and running time. For the hierarchical clustering, IGFA is used to optimize the smallest distance of genes pairs, and the results were compared with GA and SA, singular-linkage clustering, UPGMA. The efficiency of IGFA is proved.

  13. Quasar Evolution Driven by Galaxy Encounters in Hierarchical Structures

    CERN Document Server

    Menci, N; Fontana, A; Giallongo, E; Poli, F; Vittorini, V

    2003-01-01

    We link the evolution of the galaxies in the hierarchical clustering scenario with the changing accretion rates of cold gas onto the central massive black holes that power the quasars. We base on galaxy interactions as main triggers of accretion; the related scaling laws are taken up from Cavaliere & Vittorini (2000), and grafted to a semi-analytic code for galaxy formation. As a result, at high $z$ the protogalaxies grow rapidly by hierarchical merging; meanwhile, much fresh gas is imported and also destabilized, so the holes are fueled at their full Eddington rates. At lower $z$ the galactic dynamical events are mostly encounters in hierarchically growing groups; now the refueling peters out, as the residual gas is exhausted while the destabilizing encounters dwindle. So, with no parameter tuning other than needed for stellar observables, our model uniquely produces at $z>3$ a rise, and at $z\\lesssim 2.5 $ a decline of the bright quasar population as steep as observed. In addition, our results closely f...

  14. Strongly Resilient Non-Interactive Key Predistribution For Hierarchical Networks

    CERN Document Server

    Chen, Hao

    2010-01-01

    Key establishment is the basic necessary tool in the network security, by which pairs in the network can establish shared keys for protecting their pairwise communications. There have been some key agreement or predistribution schemes with the property that the key can be established without the interaction (\\cite{Blom84,BSHKY92,S97}). Recently the hierarchical cryptography and the key management for hierarchical networks have been active topics(see \\cite{BBG05,GHKRRW08,GS02,HNZI02,HL02,Matt04}. ). Key agreement schemes for hierarchical networks were presented in \\cite{Matt04,GHKRRW08} which is based on the Blom key predistribution scheme(Blom KPS, [1]) and pairing. In this paper we introduce generalized Blom-Blundo et al key predistribution schemes. These generalized Blom-Blundo et al key predistribution schemes have the same security functionality as the Blom-Blundo et al KPS. However different and random these KPSs can be used for various parts of the networks for enhancing the resilience. We also presentk...

  15. CLAG: an unsupervised non hierarchical clustering algorithm handling biological data

    Directory of Open Access Journals (Sweden)

    Dib Linda

    2012-08-01

    Full Text Available Abstract Background Searching for similarities in a set of biological data is intrinsically difficult due to possible data points that should not be clustered, or that should group within several clusters. Under these hypotheses, hierarchical agglomerative clustering is not appropriate. Moreover, if the dataset is not known enough, like often is the case, supervised classification is not appropriate either. Results CLAG (for CLusters AGgregation is an unsupervised non hierarchical clustering algorithm designed to cluster a large variety of biological data and to provide a clustered matrix and numerical values indicating cluster strength. CLAG clusterizes correlation matrices for residues in protein families, gene-expression and miRNA data related to various cancer types, sets of species described by multidimensional vectors of characters, binary matrices. It does not ask to all data points to cluster and it converges yielding the same result at each run. Its simplicity and speed allows it to run on reasonably large datasets. Conclusions CLAG can be used to investigate the cluster structure present in biological datasets and to identify its underlying graph. It showed to be more informative and accurate than several known clustering methods, as hierarchical agglomerative clustering, k-means, fuzzy c-means, model-based clustering, affinity propagation clustering, and not to suffer of the convergence problem proper to this latter.

  16. Music emotion detection using hierarchical sparse kernel machines.

    Science.gov (United States)

    Chin, Yu-Hao; Lin, Chang-Hong; Siahaan, Ernestasia; Wang, Jia-Ching

    2014-01-01

    For music emotion detection, this paper presents a music emotion verification system based on hierarchical sparse kernel machines. With the proposed system, we intend to verify if a music clip possesses happiness emotion or not. There are two levels in the hierarchical sparse kernel machines. In the first level, a set of acoustical features are extracted, and principle component analysis (PCA) is implemented to reduce the dimension. The acoustical features are utilized to generate the first-level decision vector, which is a vector with each element being a significant value of an emotion. The significant values of eight main emotional classes are utilized in this paper. To calculate the significant value of an emotion, we construct its 2-class SVM with calm emotion as the global (non-target) side of the SVM. The probability distributions of the adopted acoustical features are calculated and the probability product kernel is applied in the first-level SVMs to obtain first-level decision vector feature. In the second level of the hierarchical system, we merely construct a 2-class relevance vector machine (RVM) with happiness as the target side and other emotions as the background side of the RVM. The first-level decision vector is used as the feature with conventional radial basis function kernel. The happiness verification threshold is built on the probability value. In the experimental results, the detection error tradeoff (DET) curve shows that the proposed system has a good performance on verifying if a music clip reveals happiness emotion. PMID:24729748

  17. Hierarchical approach to forecasting recurrent solar wind streams

    Science.gov (United States)

    Shugay, Yu. S.; Veselovsky, I. S.; Seaton, D. B.; Berghmans, D.

    2011-12-01

    The hierarchical approach to predicting quasi-stationary, high-speed solar wind (SW) streams is described. This approach integrates various types of data into a single forecasting system by means of an ensemble of experts. The input data included the daily values of the coronal hole areas, which were calculated from the ultraviolet images of the Sun, and the speed of the SW streams during the previous solar rotations. The coronal hole areas were calculated from the images taken by the SWAP instrument aboard the PROBA2 satellite in the spectral interval centered at a wavelength of 17.4 nm and by the AIA instrument aboard the SDO spacecraft in the interval of wavelengths centered at 19.3 and 17.1 nm. The forecast was based on the data for 2010, corresponding to the rising phase of the 24th solar cycle. On the first hierarchical level, a few simple model estimates were obtained for the speed of the SW streams from the input data of each type. On the second level of hierarchy, the final 3 day ahead forecast of the SW velocity was formulated on the basis of the obtained estimates. The proposed hierarchical approach improves the accuracy of forecasting the SW velocity. In addition, in such a method of prediction, the data gaps in the records of one instrument do not crucially affect the final result of forecasting of the system as a whole.

  18. Hierarchical regression for analyses of multiple outcomes.

    Science.gov (United States)

    Richardson, David B; Hamra, Ghassan B; MacLehose, Richard F; Cole, Stephen R; Chu, Haitao

    2015-09-01

    In cohort mortality studies, there often is interest in associations between an exposure of primary interest and mortality due to a range of different causes. A standard approach to such analyses involves fitting a separate regression model for each type of outcome. However, the statistical precision of some estimated associations may be poor because of sparse data. In this paper, we describe a hierarchical regression model for estimation of parameters describing outcome-specific relative rate functions and associated credible intervals. The proposed model uses background stratification to provide flexible control for the outcome-specific associations of potential confounders, and it employs a hierarchical "shrinkage" approach to stabilize estimates of an exposure's associations with mortality due to different causes of death. The approach is illustrated in analyses of cancer mortality in 2 cohorts: a cohort of dioxin-exposed US chemical workers and a cohort of radiation-exposed Japanese atomic bomb survivors. Compared with standard regression estimates of associations, hierarchical regression yielded estimates with improved precision that tended to have less extreme values. The hierarchical regression approach also allowed the fitting of models with effect-measure modification. The proposed hierarchical approach can yield estimates of association that are more precise than conventional estimates when one wishes to estimate associations with multiple outcomes. PMID:26232395

  19. 基于全网统筹的联络线分层优化调度%Optimization of Tie-line Hierarchical Schedule Based on Network-wide Coordination

    Institute of Scientific and Technical Information of China (English)

    许丹; 李晓磊; 丁强; 崔晖; 韩彬

    2014-01-01

    The traditional tie-line schedule is entirely based on the electricity transaction,hence it is loosely coupled with power grid operation all along and relatively independent from the generation scheduling.These cause difficulties in adj usting tie-line schedule and lack of capacity in global allocation of resources.In face of these problems,a hierarchical tie-line schedule model based on network-wide coordination is proposed by resorting to the existing tie-line planning.The upper model gets the ideal tie-line schedule through the economical dispatch constrained by the whole network security.The lower model uses the ideal tie-line schedule as the optimization obj ective,and takes electricity transactions as constraints to achieve the tie-line schedule. This model has achieved automatic preparation and flexible adj ustment of tie-line scheduling,while providing an available manner that combines the schedule with the grid operating state.The proposed algorithm is applied to the tie-line schedule of Central China power grid,while the comparison between the proposed method and the traditional method showing the correctness and effectiveness of the proposed algorithm.%传统联络线计划完全基于电力交易,与电网运行长期处于松耦合状态且与机组计划相对独立,存在联络线计划调整困难,资源全局配置能力不足等问题。针对上述问题,文中以现有联络线计划编制方式为基础,提出了基于全网统筹的联络线分层优化模型。上层模型通过全网安全约束经济调度求取理想联络线计划。下层模型以理想联络线计划为优化目标,以交易合同实际执行为相关约束求解联络线计划。该模型实现了联络线计划自动编制与灵活调整,提供了一种将联络线计划与电网运行状态相结合的可用方式。将所提模型运用于华中电网联络线计划编制,并对优化结果与传统计划进行对比分析,验证了所提方法的正确性与有效性。

  20. Hierarchical Visual Analysis and Steering Framework for Astrophysical Simulations

    Institute of Scientific and Technical Information of China (English)

    肖健; 张加万; 原野; 周鑫; 纪丽; 孙济洲

    2015-01-01

    A framework for accelerating modern long-running astrophysical simulations is presented, which is based on a hierarchical architecture where computational steering in the high-resolution run is performed under the guide of knowledge obtained in the gradually refined ensemble analyses. Several visualization schemes for facilitating ensem-ble management, error analysis, parameter grouping and tuning are also integrated owing to the pluggable modular design. The proposed approach is prototyped based on the Flash code, and it can be extended by introducing user-defined visualization for specific requirements. Two real-world simulations, i.e., stellar wind and supernova remnant, are carried out to verify the proposed approach.