An XML-based implementation of the parametric model for ad-hoc query of temporal and spatiotemporal data

The parametric model is one of the data models for dimensional data. Values in the parametric model are defined as functions. Such modeling concept helps one achieve a one-to-one correspondence between objects in the real world and records in a database. One of the important requirements is that domains of values should be closed under the set theoretic operations such as union, intersection, and complementation. Because of this, ParaSQL, a query language of the parametric model, is able to mimic natural languages more closely. In this dissertation we validate and implement the parametric model for temporal and spatiotemporal data. We also develop a preliminary prototype for the users of NC-94, an interesting dataset in agriculture;Viewing values as functions leads variable-length tuples. Potentially, such values vary in size ranging from a few bytes to gigabytes and beyond. This makes implementation of the parametric model a challenging problem. To meet the challenge, we develop an XML-based storage and deploy it in our implementation. Incidentally, XML is also used for interfacing various modules and artifacts like parse tree, expression tree, and iterators to fetch data from a disk;The NC-94 dataset, mentioned above, contains the most complete record of spatiotemporal variables that characterize the dynamics of agriculture covering the north central region in the United States. To support ad-hoc query of data in its geospatial context, a novel hybrid structure is designed and implemented. We use GML to describe geospatial information. Use of GML is a good match, because it is XML-based. More importantly, it meets the set theoretic closure requirements proposed by the parametric model;Validation and implementation methodologies introduced in this dissertation will contribute to database and GIS communities. The validation demonstrates the ease of use and efficiency of the parametric model for temporal and spatiotemporal data. This should help settle a debate in temporal database community which has continued since the mid 1980s. The findings also extend to spatial and spatiotemporal data. It is an important baby-step toward full-fledged implementation of the parametric model. We hope that this work will also help bring database and GIS communities together

Heterogeneous data source integration for smart grid ecosystems based on metadata mining

The arrival of new technologies related to smart grids and the resulting ecosystem of applications andmanagement systems pose many new problems. The databases of the traditional grid and the variousinitiatives related to new technologies have given rise to many different management systems with several formats and different architectures. A heterogeneous data source integration system is necessary toupdate these systems for the new smart grid reality. Additionally, it is necessary to take advantage of theinformation smart grids provide. In this paper, the authors propose a heterogeneous data source integration based on IEC standards and metadata mining. Additionally, an automatic data mining framework isapplied to model the integrated information.Ministerio de Economía y Competitividad TEC2013-40767-

An XML based scalable implementation of temporal databases using parametric model

A parametric model and a query language ParaSQL for temporal databases has been proposed in the past. As the attribute values in the model can vary in length, it is difficult to use existing relational storage technology. To address this, CanStoreX, our XML-based storage technology has been deployed in a prior implementation. In parallel, the storage technology as well as our style of implementation for database prototypes have gone through an evolution. This has necessitated the previous implementation to be revisited. In addition, a new parser has been developed using JavaCC. Furthermore, a larger subset of ParaSQL has been implemented. For testing, a utility to generate synthetic temporal relations has been developed. Conforming to the new style, the present implementation has been encapsulated in terms of high level commands. This allows end-users to system developers on one hand and various database prototypes on the other, to interact with a central storage system from a common GUI that facilitates execution of batches of commands. Our implementation has helped to identify pragmatic issues in temporal database implementation as well as as the storage technology more clearly

A workbench for advanced database implementation and benchmarking

This work focuses on a methodology to help bring many of our database artifacts and prototypes to reside on the top of a common workbench platform that leads to uniformity and removes overlap across different subsystems. A versatile command format has been developed to allow commands belonging to different subsystems to be interleaved in the same batch unambiguously. Through a collaborative effort carried on in parallel, existing GUIs (Graphical User Interfaces) have also been merged into a common, but simple GUI. The GUI executes a batch of commands. Subsystem currently included are: a runner for SQL on a variety of database platforms, a runner for Quilt queries (Quilt is an early version of XQuery and runs on a platform called KWEELT), ElementalDB, an experimental database system used for instruction in a graduate database implementation course, our own XQuery engine which aims at handling data in terabyte range stored in our storage in paginated form using our pagination algorithm, a research prototype for NC94, an important spatiotemporal data set in agriculture, and a research prototype for a temporal database. The organization of the subsystems follows strict convention for ease of further development and maintenance. XML is used extensively by various subsystems. An XML based framework has been developed for benchmarking subsystems to make experiments completely repeatable at click of a button starting from creation of storage, loading of data sets, execution of commands, collecting performance data in XML-based logs to reporting using XQuery queries on the XML logs. With a very small learning curve, the resulting workbench can be used by students, instructors, developers and researchers alike and managed easily

Modeling temporal dimensions of semistructured data

In this paper we propose an approach to manage in a correct way valid time semantics for semistructured temporal clinical information. In particular, we use a graph-based data model to represent radiological clinical data, focusing on the patient model of the well known DICOM standard, and define the set of (graphical) constraints needed to guarantee that the history of the given application domain is consistent

Towards Querying and Visualization of Large Spatio-Temporal Databases

In any database model, data analysis can be eased by extracting a smaller set of the data of interest, called subset, from the mammoth original dataset. Thus, a subset helps enhance the performance of a system by avoiding the iteration through the huge parental data in further analysis. A subset, its specification, or the formal process for its extraction can be complex. In the database community, subsets are extracted through SQL-like queries and through visualization in the Geographic Information System (GIS) community. Both are iterative processes. An SQL query can be a composition of subqueries. Each subquery can be seen as an iterative step toward the extraction of the desired subset. For this to work, subqueries should result into relations that have the same structure as the relations in a given data model. Although it may not be immediately obvious, the visualization can be iterative too. Each community works in its own compartment. Either one uses subprocesses that are only subqueries or only visual interactions. Mixing these two subprocesses would yield a more powerful expressibility in the hands of users. Parametric Data Model is well-known for handling multidimensional parametric data, such as spatial, temporal, or spatio-temporal. In the parametric approach, the object is modeled as a single tuple, creating one-to-one correspondence between an object in the real world and a tuple in the database. The parametric approach relies on its own SQL-like, but richer, query language called ParaSQL which mimics the classical SQL. However, it is simpler and avoids self-join operations; hence, enhances performance. In the parametric approach, the attribute values are defined as a function, allowing large values, also. The execution of a query in the existing prototype of the Parametric Data Model results in data out, as stream in a raw text format that cannot be queried further. This is unlike classical databases, where a subset provides additional strength to a system and the prototype lacks this potential functionality. The real power of ParaSQL lies in the where clause, and previous versions of the prototype had a very simple implementation. It is expanded further in this research work to harness its hidden potential. To perform the preliminary investigation, exploratory visual analysis is an important aspect in any spatio-temporal database system. Previous versions of the prototype of Parametric Data Model completely lacked the visualization functionality. This work ensures the output of a ParaSQL (possibly a subset) will be a relation having the same format as relations in the model rather than plain text. It also attempts to expand the power of the where clause, ensuring a clean logic and more generic nature. Some important basic steps are taken to bring a visual in a way that is conducive to the structures in Parametric Data Model. The richness of GIS visualization serves as the foundation for the visual functionality of the Parametric Data Model. The query is executed on the parametric side, while the results are visualized on GIS side. This integration equips the Parametric Data Model with visualization functionality. GIS visualization also offers a click-based selection of a subset and its persistence, which later can be consumed by Parametric Data Model also. This research work establishes a two-way communication between the two communities-Parametric Data Model and GIS- where the output of one can serve as the input for the other and is an attempt to bring them together

Active Rules for Runtime Adaptivity Management

The trend over the last years clearly shows that modern Web development is evolving from traditional, HTML-based Web sites to fullfledged, complex Web applications, also equipped with active and/or adaptive application features. While this evolution unavoidably implies higher development costs and times, such implications are contrasted by the dynamics of the modern Web, which demands for even faster application development and evolution cycles. In this paper we address the above problem by focusing on the case of adaptive Web applications. We illustrate an ECA rule-based approach, intended to facilitate the management and evolution of adaptive application features. For this purpose, we stress the importance of decoupling the active logic (i.e. the adaptivity rules) from the execution of the actual application by means of a decoupled rule engine that is able to capture events and to autonomously enact adaptivity actions