To generate large number of reports in a limited time window, four techniques were proposed, including ROLAP&SQL, Shared Scanning, Hadoop based Solution, and MOLAP&Cube Sharding, an algorithm that performs in ...
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To generate large number of reports in a limited time window, four techniques were proposed, including ROLAP&SQL, Shared Scanning, Hadoop based Solution, and MOLAP&Cube Sharding, an algorithm that performs in memory aggregation was designed for the second solution. The experiment results show that all techniques except ROLAP&SQL can meet the time window constraint, the Hadoop based solution is a promising technique owe to its highly scalability. Considering maturity of the techniques and their performance, we put MOLAP&Cube Sharding into practice while keeping an eye on Hadoop for future adoption.
These tutorials/keynote speeches discuss the following: the effects of nicotine exposure on the complexity and the genetic patterns of dopamine neurons in VTA; from 6-Ps medicine to cardiovascular health informatics; ...
These tutorials/keynote speeches discuss the following: the effects of nicotine exposure on the complexity and the genetic patterns of dopamine neurons in VTA; from 6-Ps medicine to cardiovascular health informatics; computer-aided interpretation of vascular images towards valid diagnosis and risk stratification of atherosclerosis; turning data into predictions of gene and protein function; from reading to writing (and rewriting) the code of life: the future of biology - scientific, ethical, legal, civil and social issues.
Trajectories representing the motion of moving objects are typically obtained via location sampling, e.g. using GPS or road-side sensors, at discrete time-instants. In-between consecutive samples, nothing is known abo...
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ISBN:
(纸本)9781450305280
Trajectories representing the motion of moving objects are typically obtained via location sampling, e.g. using GPS or road-side sensors, at discrete time-instants. In-between consecutive samples, nothing is known about the whereabouts of a given moving object. Various models have been proposed (e.g., sheared cylinders;spacetime prisms) to represent the uncertainty of the moving objects both in unconstrained Euclidian space, as well as road networks. In this paper, we focus on representing the uncertainty of the objects moving along road networks as time-dependent probability distribution functions, assuming availability of a maximal speed on each road segment. For these settings, we introduce a novel indexing mechanism - UTH (Uncertain Trajectories Hierarchy), based upon which efficient algorithms for processing spatio-temporal range queries are proposed. We also present experimental results that demonstrate the benefits of our proposed methodologies.
Intensive research has demonstrated that shopping center attractiveness analysis, such as identifying catchment area, attracted trips, and attractiveness factors, can benefit not only market analysis, but also traffic...
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ISBN:
(纸本)9781450309332
Intensive research has demonstrated that shopping center attractiveness analysis, such as identifying catchment area, attracted trips, and attractiveness factors, can benefit not only market analysis, but also traffic management and urban planning. Conventionally, socioeconomic and survey data are needed to conduct the analysis, which is both labor-intensive and time-consuming. This study takes advantage of increasingly available taxi trajectory data to identify shopping center attractiveness using the case of Wuhan, a large city in China. The empirical results are consistent with previous studies. This demonstrates the feasibility of using trajectory data to generate choice-based sample and benefit market and related studies. Copyright 2011 ACM.
keyword search is a proven, user-friendly way to query html documents in the World Wide Web. With the trend of integrating IR technologies into DB community, state-of-the-art studies have introduced keyword search int...
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This paper presents a reference framework, called BUD, to manage a large shared bank of unstructured data. This paper lists several important issues on managing or maintaining the unstructured data in BUD. BUD stores ...
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Recently there has been a lot of interest in graph-based analysis. One of the most important aspects of graph-based analysis is to measure similarity between nodes in a graph. SimRank is a simple and influential measu...
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Certificateless cryptography eliminates the key escrow problem in identity-based cryptography. Hierarchical cryptography exploits a practical security model to mirror the organizational hierarchy in the real world. In...
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Nowadays, the key strategic issues about resource and environment, such as global warming, water resources shortage, food security etc. are more complex and multidisciplinary than ever before. In scientific research, ...
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ISBN:
(纸本)9781424473014
Nowadays, the key strategic issues about resource and environment, such as global warming, water resources shortage, food security etc. are more complex and multidisciplinary than ever before. In scientific research, the developmental tendency of modelling and integrating technique is all but irreversible. Focusing on the topic of model integration, we develop a Workflow-based Spatial Modeling Environment (WF-SME) which enables scientists and modeling users easy to design and create of complex systems models through a drag-drop operation or editing mathematical formula in model constructor. WF-SME, a visual integrated modeling environment is mainly used for the rapid realization of model dynamic integration, in which we can implement the composition and connection of the existing models, and generate new model through graphical operation. The papers firstly introduce the framework of model integration designed for WF-SME as well as its supporting theory, and then explain in detail how the modules of WF-SME have been realized. WF-SME is a platform for spatial modelling, which was designed in four parts, Spatial Workflow Designer, Model builder, Spatial Calculation engine and Visualization of Modelling Output. The spatial workflow designer built-in WFSME shipping with toolsets was adopted to create spatial workflow, reuse and aggregate models. Consisting of equation editor and data banding tool, the model builder enable modeller updates formulas on-demand. This editor parsed by MathML is powerful and flexible enough for the requirements of expressions of mathematical calculations. The spatial calculating engine developed based on component, through the map algebra language, executes mathematical calculations. The multi-form visualization module was developed to provide visual expression for a series of intermediate data and its result of the domain models. Finally, we illustrate how the typical practical application sample has been modeled in our modeling environment
This paper considers the problem of constructing data aggregation trees in wireless sensor networks (WSNs)for a group of sensor nodes to send collected information to a single sink *** data aggregation tree contains t...
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This paper considers the problem of constructing data aggregation trees in wireless sensor networks (WSNs)for a group of sensor nodes to send collected information to a single sink *** data aggregation tree contains the sink node,all the source nodes,and some other non-source *** goal of constructing such a data aggregation tree is to minimize the number of non-source nodes to be included in the tree so as to save *** prove that the data aggregation tree problem is NP-hard and then propose an approximation algorithm with a performance ratio of four and a greedy *** also give a distributed version of the approximation *** simulations are performed to study the performance of the proposed *** results show that the proposed algorithms can find a tree of a good approximation to the optimal tree and has a high degree of scalability.
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