Dissertations / Theses on the topic 'Load graph'
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Barat, Remi. "Load Balancing of Multi-physics Simulation by Multi-criteria Graph Partitioning." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0961/document.
Full textMultiphysics simulation couple several computation phases. When they are run in parallel on memory-distributed architectures, minimizing the simulation time requires in most cases to balance the workload across computation units, for each computation phase. Moreover, the data distribution must minimize the induced communication. This problem can be modeled as a multi-criteria graph partitioning problem. We associate with each vertex of the graph a vector of weights, whose components, called “criteria”, model the workload of the vertex for each computation phase. The edges between vertices indicate data dependencies, and can be given a weight representing the communication volume transferred between the two vertices. The goal is to find a partition of the vertices that both balances the weights of each part for each criterion, and minimizes the “edgecut”, that is, the sum of the weights of the edges cut by the partition. The maximum allowed imbalance is provided by the user, and we search for a partition that minimizes the edgecut, among all the partitions whose imbalance for each criterion is smaller than this threshold. This problem being NP-Hard in the general case, this thesis aims at devising and implementing heuristics that allow us to compute efficiently such partitions. Indeed, existing tools often return partitions whose imbalance is higher than the prescribed tolerance. Our study of the solution space, that is, the set of all the partitions respecting the balance constraints, reveals that, in practice, this space is extremely large. Moreover, we prove in the mono-criterion case that a bound on the normalized vertex weights guarantees the existence of a solution, and the connectivity of the solution space. Based on these theoretical results, we propose improvements of the multilevel algorithm. Existing tools implement many variations of this algorithm. By studying their source code, we emphasize these variations and their consequences, in light of our analysis of the solution space. Furthermore, we define and implement two initial partitioning algorithms, focusing on returning a solution. From a potentially imbalanced partition, they successively move vertices from one part to another. The first algorithm performs any move that reduces the imbalance, while the second performs at each step the move reducing the most the imbalance. We present an original data structure that allows us to optimize the choice of the vertex to move, and leads to partitions of imbalance smaller on average than existing methods. We describe the experimentation framework, named Crack, that we implemented in order to compare the various algorithms at stake. This comparison is performed by partitioning a set of instances including an industrial test case, and several fictitious cases. We define a method for generating realistic weight distributions corresponding to “Particles-in-Cells”-like simulations. Our results demonstrate the necessity to coerce the vertex weights during the coarsening phase of the multilevel algorithm. Moreover, we evidence the impact of the vertex ordering, which should depend on the graph topology, on the efficiency of the “Heavy-Edge” matching scheme. The various algorithms that we consider are implemented in an open- source graph partitioning software called Scotch. In our experiments, Scotch and Crack returned a balanced partition for each execution, whereas MeTiS, the current most used partitioning tool, fails regularly. Additionally, the edgecut of the solutions returned by Scotch and Crack is equivalent or better than the edgecut of the solutions returned by MeTiS
Predari, Maria. "Load balancing for parallel coupled simulations." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0369/document.
Full textLoad balancing is an important step conditioning the performance of parallel applications. The goal is to distribute roughly equal amounts of computational load across a number of processors, while minimising interprocessor communication. A common approach to model the problem is based on graph structures and graph partitioning algorithms. Moreover, new challenges involve the simulation of more complex physical phenomena, where different parts of the computational domain exhibit different physical behavior. Such simulations follow the paradigm of multi-physics or multi-scale modeling approaches. Combining such different models in massively parallel computations is still a challenge to reach high performance. Additionally, traditional load balancing algorithms are often inadequate, and more sophisticated solutions should be explored. In this thesis, we propose new graph partitioning algorithms that balance the load of such simulations, refered to as co-partitioning. We formulate this problem with the use of graph partitioning with initially fixed vertices which we believe represents efficiently the additional constraints of coupled simulations. We have therefore developed a direct algorithm for graph partitioning that manages successfully problems with fixed vertices. The algorithm is implemented inside Scotch partitioner and a series of experiments were carried out on the DIMACS graph collection. Moreover we proposed three copartitioning algorithms that respect the constraints of the respective coupled codes. We finally validated our algorithms by an experimental study comparing our methods with current strategies on artificial cases and on real-life coupled simulations
Sun, Jiawen. "The GraphGrind framework : fast graph analytics on large shared-memory systems." Thesis, Queen's University Belfast, 2018. https://pure.qub.ac.uk/portal/en/theses/the-graphgrind-framework-fast-graph-analytics-on-large-sharedmemory-systems(e1eb006f-3a68-4d05-91fe-961d04b42694).html.
Full textDeveci, Mehmet. "Load-Balancing and Task Mapping for Exascale Systems." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1429199721.
Full textBotadra, Harnish. "iC2mpi a platform for parallel execution of graph-structured iterative computations /." unrestricted, 2006. http://etd.gsu.edu/theses/available/etd-07252006-165725/.
Full textTitle from title screen. Sushil Prasad, committee chair. Electronic text (106 p. : charts) : digital, PDF file. Description based on contents viewed June 11, 2007. Includes bibliographical references. Includes bibliographical references (p. 61-53).
Yildiz, Ali. "Resource-aware Load Balancing System With Artificial Neural Networks." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607613/index.pdf.
Full textZheng, Chunfang. "GRAPHICAL MODELING AND SIMULATION OF A HYBRID HETEROGENEOUS AND DYNAMIC SINGLE-CHIP MULTIPROCESSOR ARCHITECTURE." UKnowledge, 2004. http://uknowledge.uky.edu/gradschool_theses/249.
Full textGillet, Noel. "Optimisation de requêtes sur des données massives dans un environnement distribué." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0553/document.
Full textDistributed data store are massively used in the actual context of Big Data. In addition to provide data management features, those systems have to deal with an increasing amount of queries sent by distant users in order to process data mining or data visualization operations. One of the main challenge is to evenly distribute the workload of queries between the nodes which compose these system in order to minimize the treatment time. In this thesis, we tackle the problem of query allocation in a distributed environment. We consider that data are replicated and a query can be handle only by a node storing the concerning data. First, near-optimal algorithmic proposals are given when communications between nodes are asynchronous. We also consider that some nodes can be faulty. Second, we study more deeply the impact of data replication on the query treatement. Particularly, we present an algorithm which manage the data replication based on the demand on these data. Combined with our allocation algorithm, we guaranty a near-optimal allocation. Finally, we focus on the impact of data replication when queries are received as a stream by the system. We make an experimental evaluation using the distributed database Apache Cassandra. The experiments confirm the interest of our algorithmic proposals to improve the query treatement compared to the native allocation scheme in Cassandra
Tbaileh, Ahmad Anan. "Robust Non-Matrix Based Power Flow Algorithm for Solving Integrated Transmission and Distribution Systems." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/89362.
Full textPHD
Cheng, Danling. "Integrated System Model Reliability Evaluation and Prediction for Electrical Power Systems: Graph Trace Analysis Based Solutions." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/28944.
Full textPh. D.
Silva, Rafael Ennes. "Escalonamento estático de programas-MPI." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2006. http://hdl.handle.net/10183/11472.
Full textA good performance of a parallel application is obtained according to the mode as the parallelization techniques are applied. To make use of these techniques, is necessary to nd an appropriate way to extract the parallelism. This extraction can be done through a representative graph of the application. In this work, methods of partitioning graphs are applied to optimize the communication between processes that belong to a parallel computation. In this context, the processes allocation aims to minimize the communication amount between processors. This technique is frequently adopted in High Performance Computing - HPC. However, the graph building is generally inside the program, that has private data structures employed in the graph building. The proposal is to utilize tools directly in MPI programs, employing only standard resources of the MPI 1.2 norm. The goal is to provide a portable library (b -MPI) to static schedule MPI programs. The static scheduling realized by the library is done through the mapping of processes. This mapping seeks to cluster the processes that exchange a lot of information in the same machine that, in this case decreases the data volume passed through the net. The mapping will be done staticly after a previous execution of a MPI program. The target applications to make use of b -MPI are those whose keep the same communication pattern after successives executions. The library validation is done through the available applications in the FFTW package, the solving of the problem of Heat Transference through the Additive Schwarz Method and Multigrid and the LU factorization implemented in the HPL benchmark. The results show that b -MPI can be utilized to distribute the processes ef ciently minimizing the volume of messages exchanged through the network.
Helders, Fredrik. "Visualizing Carrier Aggregation Combinations." Thesis, Linköpings universitet, Kommunikationssystem, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-160132.
Full textI samband med att trådlösa kommunikationssystem blir en allt större del av våraliv och mängden data som skickas fortsätter att stiga, skapas en efterfrågan förökade datatakter. En av teknologierna som används för att skapa högre datatakterär bäraraggregering (carrier aggregation), som möjliggör för trådlösa enheteratt kombinera flertalet uppkopplingar mot det mobila nätverket. Det finns dockbara ett begränsat antal kombinationer definierade, vilket skapar ett behov av attsöka upp den bästa kombinationen i varje givet tillfälle. Detta arbete introducerarmjukvara som organiserar dessa kombinationer i trädstrukturer, vilket förenklarsökning efter optimala kombinationer tillsammans med möjligheten att visualiserade potentiella uppkopplingarna. I arbetet presenteras en föreslagen metodför att skapa dessa träd, tillsammans med uppslag på hur viktiga egenskaperhos kombinationerna kan visualiseras. Olika trädsökningsalgoritmer har ocksåundersökts, och det visas att det inte är nödvändigt att söka igenom hela träd.Istället visar sig giriga algoritmer ha hög prestanda, samtidigt som sökstorlekenkan hållas kraftigt begränsad.
Fourestier, Sébastien. "Redistribution dynamique parallèle efficace de la charge pour les problèmes numériques de très grande taille." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00873816.
Full textAl-Ameri, Shehab Ahmed. "A framework for assessing robustness of water networks and computational evaluation of resilience." Thesis, Cranfield University, 2016. http://dspace.lib.cranfield.ac.uk/handle/1826/12334.
Full textVuchener, Clement. "Equilibrage de charges dynamique avec un nombre variable de processeurs basé sur des méthodes de partitionnement de graphe." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0012/document.
Full textLoad balancing is an important step conditioning the performance of parallel programs. If the workload varies drastically during the simulation, the load must be redistributed regularly among the processors. Dynamic load balancing is a well studied subject but most studies are limited to an initially fixed number of processors. Adjusting the number of processors at runtime allows to preserve the parallel code efficiency or to keep running the simulation when the memory of the current resources is exceeded.In this thesis, we propose some methods based on graph repartitioning in order to rebalance the load while changing the number of processors. We call this problem \M x N repartitioning". These methods are split in two main steps. Firstly, we study the migration phase and we build a \good" migration matrix minimizing several metrics like the migration volume or the number of exchanged messages. Secondly, we use graph partitioning heuristics to compute a new distribution optimizing the migration according to the previous step results. Besides, we propose a direct k-way partitioning algorithm that allows us to improve our biased partitioning. Finally, an experimental study validates our algorithms against state-of-the-art partitioning tools
Sattar, Naw Safrin. "Scalable Community Detection using Distributed Louvain Algorithm." ScholarWorks@UNO, 2019. https://scholarworks.uno.edu/td/2640.
Full textHong, Changwan. "Code Optimization on GPUs." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1557123832601533.
Full textMastio, Matthieu. "Modèles de distribution pour la simulation de trafic multi-agent." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1147/document.
Full textNowadays, analysis and prediction of transport network behavior are crucial elements for the implementation of territorial management policies. Computer simulation of road traffic is a powerful tool for testing management strategies before deploying them in an operational context. Simulation of city-wide traffic requires significant computing power exceeding the capacity of a single computer.This thesis studies the methods to perform large-scale multi-agent traffic simulations. We propose solutions allowing the distribution of such simulations on a large amount of computing cores.One of them distributes the agents directly on the available cores, while the second splits the environment on which the agents evolve. Graph partitioning methods are studied for this purpose, and we propose a partitioning procedure specially adapted to the multi-agent traffic simulation. A dynamic load balancing algorithm is also developed to optimize the performance of the microscopic simulation distribution.The proposed solutions have been tested on a real network representing the Paris-Saclay area.These solutions are generic and can be applied to most existing simulators.The results show that the distribution of the agents greatly improves the performance of the macroscopic simulation, whereas the environment distribution is more suited to microscopic simulation. Our load balancing algorithm also significantly improves the efficiency of the environment based distribution
Jule, Alan. "Etude des codes en graphes pour le stockage de données." Thesis, Cergy-Pontoise, 2014. http://www.theses.fr/2014CERG0739.
Full textFor two decades, the numerical revolution has been amplified. The spread of digital solutions associated with the improvement of the quality of these products tends to create a growth of the amount of data stored. The cost per Byte reveals that the evolution of hardware storage solutions cannot follow this expansion. Therefore, data storage solutions need deep improvement. This is feasible by increasing the storage network size and by reducing data duplication in the data center. In this thesis, we introduce a new algorithm that combines sparse graph code construction and node allocation. This algorithm may achieve the highest performance of MDS codes in terms of the ratio R between the number of parity disks and the number of failures that can be simultaneously reconstructed. In addition, encoding and decoding with sparse graph codes helps lower the complexity. By this algorithm, we allow to generalize coding in the data center, in order to reduce the amount of copies of original data. We also study Spatially-Coupled LDPC (SC-LDPC) codes which are known to have optimal asymptotic performance over the binary erasure channel, to anticipate the behavior of these codes decoding for distributed storage applications. It is usually necessary to compromise between different parameters for a distributed storage system. To complete the state of the art, we include two theoretical studies. The first study deals with the computation complexity of data update and we determine whether linear code used for data storage are update efficient or not. In the second study, we examine the impact on the network load when the code parameters are changed. This can be done when the file status changes (from a hot status to a cold status for example) or when the size of the network is modified by adding disks. All these studies, combined with the new algorithm for sparse graph codes, could lead to the construction of new flexible and dynamical networks with low encoding and decoding complexities
Abu-Aisheh, Zeina. "Approches anytime et distribuées pour l'appariment de graphes." Thesis, Tours, 2016. http://www.theses.fr/2016TOUR4024/document.
Full textDue to the inherent genericity of graph-based representations, and thanks to the improvement of computer capacities, structural representations have become more and more popular in the field of Pattern Recognition (PR). In a graph-based representation, vertices and their attributes describe objects (or part of them) while edges represent interrelationships between the objects. Representing objects by graphs turns the problem of object comparison into graph matching (GM) where correspondences between vertices and edges of two graphs have to be found
Катюха, Ігор Анатолійович. "Прогнозні моделі електричних навантажень розподільчих мереж в умовах невизначеності вихідної інформації." Thesis, Таврійський державний агротехнологічний університет, 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/31033.
Full textThe thesis for getting scientific degree of the Candidate of technical science on the specialty 05.14.02 «Electric power stations, network and system» (141 Electrical energetics, electrical engineering and electromechanics). – Tavricheskiy State Agrotechnology University, Melitopol, Ukraine National Technical University «Kharkiv Polytechnic Institute» MES of Ukraine, Kharkiv, 2017. The dissertation devoted to solving actual scientific and technical problem of development of modern science and analytical tools forecast electricity consumption in the face of uncertainty, taking into account the possibility of information support automated systems of commercial accounting of electric power and features of individual consumers and aims to increase efficiency and save electricity. Improved method of fuzzy regression analysis to build long–term forecasting models of electric loads in distribution networks. Included balanced participation of two performance criteria fuzzy models: the degree of combination and degree of fuzziness when building predictive models. The method of correction term predictive models for short–term forecast. An approach to building the type of predictive models in any type of stress. Analytical contacted fuzzy indicators forecast accuracy Mean absolute percentage error. The technique was tested in the development of predictive models of electric load number of consumers with different types of load charts. The main results of the dissertation found practical application in the form of hardware and software to automate the process of long–term and operational forecasting electricity consumers of electrical loads that can integrate information into an automated accounting system of electricity, as well as operational management mode of distribution networks. VII As a result of the research on the theme of the thesis, the following scientific results were obtained: - the method for obtaining predictive models of electrical loads is improved, which is distinguished by constructing a fuzzy regression compatibility criterion based on the intersection of fuzzy numbers, which makes it possible to uncover the uncertainty of the output data and improve the quality of the prediction of electrical loads. - for the first time the method of unification of the type of forecasting models is proposed, which differs in the fact that in the daily schedule of electricity consumption allocated functional areas, with the separate use for them of fuzzy regression analysis, which allows you to get the kind of forecast models at all loads. - for the first time the method of increasing the adequacy of models obtained on the basis of fuzzy regression analysis, which differs from the parity considering the degree of compatibility and the degree of fuzzy description, which will make prediction of electrical loads more qualitative. - for the first time an analytical method for determining the efficiency of the forecast of electricity consumption in electric networks is determined, which allows to perform a comparative analysis of fuzzy regression models of the forecast with models obtained by other methods. The practical significance of the obtained results of work for the electric power industrylies in the developed method of forecasting electricity consumption based on fuzzy regression analysis, which includes the principles of constructing predictive models, algorithmic support, as well as software implemented in a convenient for integration in AMSCA form. The research results are implemented and confirmed by the relevant acts: - PE "Molokozavod-OLKOM" for the analysis of electricity consumption and operational control in order to reduce energy losses in the network of intra-electric power supply. VIII - in the educational process, the main results of the work are included in the relevant disciplines - "Practical engineering training" and "Engineering activities" in the specialty: 8.10010101 - Power engineering of agricultural production. - Azov REM OJSC "Zaporizhiaoblenergo" used a hardware and software complex for the process of long-term and short-term prediction of electrical loads and operational control of the modes of distribution networks. The basic scientific positions on the materials of the dissertation work are published in 15 printed works, including 9 articles in the scientific professional editions of Ukraine (5 in the publications included in the international science-computer bases, 1 ¬ in the edition with the index SCORUS), 6 in the materials of the conferences and workshops. Thesis consists of introduction, abstract, four sections, conclusions, list of used sources and applications. The total volume of the dissertation is 190 pages, among them: 18 figures in the text, 20 tables in the text, the list of used sources contains 115 titles in 12 pages, applications in 19 pages.
Perarnau, Swann. "Environnements pour l'analyse expérimentale d'applications de calcul haute performance." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00650047.
Full textКатюха, Ігор Анатолійович. "Прогнозні моделі електричних навантажень розподільчих мереж в умовах невизначеності вихідної інформації." Thesis, НТУ "ХПІ", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/31032.
Full textDissertation for scientific degree of candidate of technical sciences, specialty 05.14.02 – electric power stations, networks and systems. – Tavricheskiy State Agrotechnology University, Melitopol, 2017. The dissertation devoted to solving actual scientific and technical problem of development of modern science and analytical tools forecast electricity consumption in the face of uncertainty, taking into account the possibility of information support automated systems of commercial accounting of electric power and features of individual consumers and aims to increase efficiency and save electricity. Improved method of fuzzy regression analysis to build long–term forecasting models of electric loads in distribution networks. Included balanced participation of two performance criteria fuzzy models: the degree of combination and degree of fuzziness when building predictive models. The method of correction term predictive models for short–term forecast. An approach to building the type of predictive models in any type of stress. Analytical contacted fuzzy indicators forecast accuracy Mean absolute percentage error. The technique was tested in the development of predictive models of electric load number of consumers with different types of load charts. The main results of the dissertation found practical application in the form of hardware and software to automate the process of long–term and operational forecasting electricity consumers of electrical loads that can integrate information into an automated accounting system of electricity, as well as operational management mode of distribution networks.
Mert, Mecnun. "Effect Of High Hydrostatic Pressure On Microbial Load And Quality Parameters Of Grape Juice." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611536/index.pdf.
Full textC) and holding time (5-10-15 min) was studied. Increased pressure and temperature showed significant effect on microbial reduction in white and red grape juices (p<
0.05). The effect of pressure and time on pH drop was found to be insignificant (p>
0.05). HHP resulted in E<
1 for white grape and E<
7 for red grape juice samples. Shelf life analysis for HHP treated white grape juice (200 MPa-40°
C-10min) and red grape juice (250 MPa-40°
C-10min) revealed no microbial growth up to 90 days when stored at 25°
C. Although HMF formation was observed in industrially manufactured, pasteurized samples (65°
C for 30 min), no HMF was detected in HHP treated white and red grape juices. HHP at the suggested conditions can be recommended as a better production alternative to heat treatment for white and red grape juice with respect to microbial load and studied quality parameters even at temperatures lower than required for pasteurization.
Casadei, Astrid. "Optimisations des solveurs linéaires creux hybrides basés sur une approche par complément de Schur et décomposition de domaine." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0186/document.
Full textIn this thesis, we focus on the parallel solving of large sparse linear systems. Our main interestis on direct-iterative hybrid solvers such as HIPS, MaPHyS, PDSLIN or ShyLU, whichrely on domain decomposition and Schur complement approaches. Althrough these solvers arenot as time and space consuming as direct methods, they still suffer from serious overheads. Ina first part, we thus present the existing techniques for reducing the memory consumption, andwe present a new method which does not impact the numerical robustness of the preconditioner.This technique reduces the memory peak by doing a special scheduling of computation, allocation,and freeing tasks in particular in the Schur coupling blocks of the matrix. In a second part,we focus on the load balancing of the domain decomposition in a parallel context. This problemconsists in partitioning the adjacency graph of the matrix in as many domains as desired. Wepoint out that a good load balancing for the most expensive steps of an hybrid solver such asMaPHyS relies on the balancing of both interior nodes and interface nodes of the domains.Through, until now, graph partitioners such as MeTiS or Scotch used to optimize only thefirst criteria (i.e., the balancing of interior nodes) in the context of sparse matrix ordering. Wepropose different variations of the existing algorithms to improve the balancing of interface nodesand interior nodes simultaneously. All our changes are implemented in the Scotch partitioner.We present our results on large collection of matrices coming from real industrial cases
Kamfer, De Witt. "The effect of maturity and crop load on the browning and concentration of phenolic compounds of Thompson Seedless and Regal Seedless." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95886.
Full textENGLISH ABSTRACT: Thompson Seedless and Regal Seedless are two white seedless table grape cultivars widely produced in South Africa. Both cultivars are susceptible to berry browning, especially Regal Seedless. Browning leads to annual financial losses for table grape growers. Although a correlation between harvest maturity and the occurrence of browning seems to exist, it is still unclear whether maturity levels are the actual contributing factor. The aim of the study was to establish if harvest maturity and crop load could influence the occurrence of browning of both cultivars. The impact of harvest maturity and crop load on phenolic compound concentration in the berry skin of both cultivars was also investigated. Total external browning of Regal Seedless and Thompson Seedless occurred in much higher percentages than internal browning. Regal Seedless showed a tendency to decreased total external browning with harvest maturity. The main reason for this is that net-like browning, which is the greatest contributor to total external browning, decreased with harvest maturity, in all three seasons. External browning of Thompson Seedless increased with harvest maturity in both seasons. Contact browning was the greatest contributor to total external browning of Thompson Seedless. Crop load did not significantly influence berry browning of Regal Seedless or Thompson Seedless grapes. The flavan-3-ol concentration (catechin, epicatechin, procyanidin B1 and procyanidin B2) in Regal Seedless generally increased with harvest maturity, whereas in Thompson Seedless the general tendency was a decrease in the flavan-3-ol concentration with harvest maturity. The development of phenolic compound concentration with maturity could not be correlated with the occurrence of berry browning. Crop load did not affect flavan-3-ol concentration. When the flavan-3-ol concentration of Regal Seedless and Thompson Seedless were compared at different harvest maturities the concentrations of flavan-3-ols were clearly much higher in the skin of Regal Seedless than in the skin of Thompson Seedless (for both the 2008 & 2009 seasons). Comparison of the browning incidence with harvest maturity for these two cultivars (see above) clearly reveals that external browning of Regal Seedless occurred in much higher percentages than on Thompson Seedless. Regal Seedless had much higher levels of external browning than Thompson Seedless. The concentration of flavan-3-ols in the skin of white seedless cultivars may be an indication of the cultivar’s susceptibility to external browning.
AFRIKAANSE OPSOMMING: Thompson Seedless en Regal Seedless is twee wit pitlose tafeldruif kultivars wat ekstensief in Suid-Afrika verbou word. Verbruining kan ‘n probleem wees by beide kultivars, spesifiek Regal Seedless. Die faktore wat aanleiding gee tot verbruining is nog nie duidelik bepaal nie. Alhoewel dit lyk of daar ‘n korrelasie tussen rypheidsgraad van die oes en verbruining kan wees is dit steeds onduidelik of oesrypheidsvlakke die werklike oorsaak van verbruining is. Die doel van die studie was om vas te stel of die rypheidsgraad van die oes en oeslading verbruining van beide kultivars kan beïnvloed. Die effek van oes rypheidsgraad en oeslading op konsentrasie van fenoliese verbindings in die korrelskil van beide kultivars is ook ondersoek. Totale eksterne verbruining van Regal Seedless en Thompson Seedless het in baie hoër persentasies voorgekom as interne verbruining. Daar was ‘n tendens by Regal Seedless dat totale eksterne verbruining verminder het soos die oes ryper geraak het as gevolg van netagtige verbruining, wat die grootste bydrae tot totale eksterne verbruining veroorsaak het. Netagtige verbruining se voorkoms het verminder oor al drie seisoene. Eksterne verbruining van Thompson Seedless het toegeneem met oes rypheid in beide seisoene. Kontak verbruining het grootste byrdae gelewer tot totale eksterne verbruining van Thompson Seedless. Oeslading het nie ‘n betekenisvolle invloed op verbruining van Regal Seedless en Thompson Seedless gehad nie. Die flavan-3-ol (katesjien, epikatesjien, prosianidien B1 en prosianidien B2) konsentrasie van Regal Seedless het met oes rypheid toegeneem. By Thompson Seedless was daar ‘n afname in die flavan-3-ol konsentrasie met oes rypheid. Daar was geen korrrelasie tussen die konsentrasie van fenoliese verbinding en die voorkoms van verbruining vir beide kultivars. Oeslading het nie ‘n betekenisvolle effek op die konsentrasie van fenoliese verbindings gehad nie. Vergelyking van die flavan-3-ol konsentrasie van Regal Seedless en Thompson Seedless by verskillende rypheidsgrade wys dat die konsentrasie baie hoër in die korrel skil van Regal Seedless as in die van Thompson Seedless (vir beide 2008 & 2009 seisoene). Die vergelyking van die voorkoms van verbruining met oesrypheid van beide kultivars wys duidelik dat eksterne verbruining van Regal Seedless in baie hoër persentasies voorkom as in Thompson Seedless. Flavan-3-ol konsentrasie in die skil van wit pitlose kultivars kan ‘n aanduiding wees van die kultivar se moontlike risiko vir die voorkoms van eksterne verbruining.
Hickey, Cain Charles. "Vines of different capacity and water status alter the sensory perception of Cabernet Sauvignon wines." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/42667.
Full textMaster of Science
Hill, Brycen Thomas. "Root restriction, under-trellis cover cropping, and rootstock modify vine size and berry composition of Cabernet Sauvignon." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/75223.
Full textMaster of Science
Delanaux, Rémy. "Intégration de données liées respectueuse de la confidentialité." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1303.
Full textIndividual privacy is a major and largely unexplored concern when publishing new datasets in the context of Linked Open Data (LOD). The LOD cloud forms a network of interconnected and publicly accessible datasets in the form of graph databases modeled using the RDF format and queried using the SPARQL language. This heavily standardized context is nowadays extensively used by academics, public institutions and some private organizations to make their data available. Yet, some industrial and private actors may be discouraged by potential privacy issues. To this end, we introduce and develop a declarative framework for privacy-preserving Linked Data publishing in which privacy and utility constraints are specified as policies, that is sets of SPARQL queries. Our approach is data-independent and only inspects the privacy and utility policies in order to determine the sequence of anonymization operations applicable to any graph instance for satisfying the policies. We prove the soundness of our algorithms and gauge their performance through experimental analysis. Another aspect to take into account is that a new dataset published to the LOD cloud is indeed exposed to privacy breaches due to the possible linkage to objects already existing in the other LOD datasets. In the second part of this thesis, we thus focus on the problem of building safe anonymizations of an RDF graph to guarantee that linking the anonymized graph with any external RDF graph will not cause privacy breaches. Given a set of privacy queries as input, we study the data-independent safety problem and the sequence of anonymization operations necessary to enforce it. We provide sufficient conditions under which an anonymization instance is safe given a set of privacy queries. Additionally, we show that our algorithms are robust in the presence of sameAs links that can be explicit or inferred by additional knowledge. To conclude, we evaluate the impact of this safety-preserving solution on given input graphs through experiments. We focus on the performance and the utility loss of this anonymization framework on both real-world and artificial data. We first discuss and select utility measures to compare the original graph to its anonymized counterpart, then define a method to generate new privacy policies from a reference one by inserting incremental modifications. We study the behavior of the framework on four carefully selected RDF graphs. We show that our anonymization technique is effective with reasonable runtime on quite large graphs (several million triples) and is gradual: the more specific the privacy policy is, the lesser its impact is. Finally, using structural graph-based metrics, we show that our algorithms are not very destructive even when privacy policies cover a large part of the graph. By designing a simple and efficient way to ensure privacy and utility in plausible usages of RDF graphs, this new approach suggests many extensions and in the long run more work on privacy-preserving data publishing in the context of Linked Open Data
Kuo, Ming-Chia, and 郭明嘉. "An Efficient Dynamic Load-Balancing Large Scale Graph-Processing System." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/kpmh4n.
Full text國立臺灣大學
資訊工程學研究所
106
Since the introduction of pregel by Google, several large-scale graphprocessing systems have been introduced. These systems are based on the bulk synchronous parallel model or other similar models and use various strategies to optimize system performance. For example, Mizan monitors the workload of each worker to determine whether the workload between the workers is balanced with respect to the execution time. If the workload is unbalanced among workers, Mizan migrates nodes from overloaded workers to under-loaded workers to balance the load among workers and minimize the total execution time. On the basis of Mizan’s migration plan, we implement a graph-processing system called GPSer with an efficient re-partitioning graph scheme. Our system uses statistical tools, e.g., coefficient of variation and correlation coefficient, to modify the migration plan and determine whether the workloads are balanced among all workers. Our system can accurately monitor current workloads and decide whether to migrate nodes among workers to balance the load. When imbalance arises, the workload of all workers can quickly converge to a balanced state, thereby enhancing the system performance. In experiment our system outperforms the state-of-the-art dynamic load-balancing graph processing-system, such as Mizan.
Gao, Pu. "Generation and properties of random graphs and analysis of randomized algorithms." Thesis, 2010. http://hdl.handle.net/10012/4987.
Full textZhang, Li-Wen, and 張力文. "Application of Grid Rational Algorithm for Predicting Hydrograph (GRAPH) Model in Suspended Load Estimation for a Watershed." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/24012197829253335659.
Full text國立中興大學
水土保持學系所
103
Geologic condition in Chingshui River watershed became more fragile after Chi-Chi earthquake. Lots of sediments transported by the torrential floods during the following typhoon seasons cause huge hazards which threaten the protected targets located at the downstream areas. However, the suspend load has its uncertainties and difficult to measure during typhoon event. Alternatively, the indirect estimation of suspend load, which applicable provide early response and handling of disaster prevention, should be proposed. This study, a hydrologic model (Grid Rational Algorithm for Predicting Hydrograph, GRAPH) was used to simulate the runoff hydrograph in Chingshui watershed. Moreover, the suspended load during the typhoon and/or heavy rainfall event would be estimated from hourly discharge and compared with measure data. The results show that the events with high peak flow (return period greater than 5 years) perform better consistency in suspended load estimation (about 10% errors); while the events with medium peak flow (return period: 3-4 years) showing errors within the range of 30% to 50% due to sensitivity of rising and recession limb in hydrograph simulation. This study reveals that the model was suitable to estimate suspended load under high peak flow. The higher peak flow it was, the more accurate it has. The results show that there is a good accuracy for small error and variation in suspended load estimated using a smaller time scale. Relationship of suspended load and discharge will be ignored briefly while adopting larger time scale due to temporal dependence of variation in sediment concentration which varied with discharge, and the power relations existing between discharge and suspended load. Therefore, this study uses hourly discharge and suspended concentration to simulate amount of suspended load for each torrential event in order to have better accuracy estimation comparing with daily discharge. Simulation results show that the concentration of suspended load was affected significantly by the changes of watershed landslide. There is a negative relationship between correction coefficient α of the model and collapse rate while correction coefficient β showing positive correlation with collapse rate. These imply that the more collapse rate, the worse the conservation ability of water resources in watershed, and the higher sediment concentration in discharge.
Liao, Chia-Ying, and 廖家瑩. "The Effect of Trigger-based Animated Instruction on Learning Achievement and Cognitive Load in Simple Quadratic Functions Graph." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/01176774279264291417.
Full text國立交通大學
理學院科技與數位學習學程
98
Trigger-based Animated Instruction is based on the concept of cognitive load theory and multimedia learning theory. Based on the Trigger-based Animated Instruction, instructors design teaching materials corresponded to classroom instructions, which contribute to guiding attention more easily; and help students take the initiative to search, select and organize information; reduce the burden on working memory as well as cognitive load; and enhance learning. This study adopted a quasi-experimental design by using the simple quadratic function graph of mathematics teaching material, to examine learning achievement and cognitive load cross two different instructions, i.e. the trigger-base animated instruction and the traditional methodology. The result of this study shows that adopting the trigger-based animated instruction significantly helps students learn more effectively, and reduces the cognitive load. Additionally, the effect was more pronounced for high-achieving students.
González, García José Luis. "Graph Partitioning for the Finite Element Method: Reducing Communication Volume with the Directed Sorted Heavy Edge Matching." Doctoral thesis, 2019. http://hdl.handle.net/11858/00-1735-0000-002E-E625-0.
Full textBagchi, Arijit. "Modeling the Power Distribution Network of a Virtual City and Studying the Impact of Fire on the Electrical Infrastructure." Thesis, 2009. http://hdl.handle.net/1969.1/147910.
Full text廖慶榮. "= Efficient partitioning and load-balancing methods for finite element graphs on distributed memory multicomputer." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/53801561416999492772.
Full textRavindran, Rajeswaran Chockalingapuram. "Scheduling Heuristics for Maximizing the Output Quality of Iris Task Graphs in Multiprocessor Environment with Time and Energy Bounds." 2012. https://scholarworks.umass.edu/theses/826.
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