An XML Representation of the Parametric Data Model for Temporal Data

This paper introduces an XML representation for the parametric data model handling temporal data. The parametric data model represents an object either in a single tuple or in multiple tuples. This feature reduces query complexities at the user level and provides elegant approaches to manage temporal data. However, this property requires the data model to have flexible attribute value sizes and causes the implementation complexity despite its advantages. To solve this problem, parametric databases have to manage variable attribute value sizes, which are in the same attribute field. XML can provide a feasible solution to represent parametric databases. XML does not have any boundary restrictions. In this paper, we introduce an XML representation scheme for the parametric data model and show that the scheme reflects the properties in the parametric data model

Literature Review on Temporal, Spatial, and Spatiotermpoal Data Models

This paper reviews papers on temporal databases, spatial databases, and spatio-temporal databases

XPDec: an XML plagiarism detection system for procedural programming languages

Plagiarisms are frequently occurring in the Computer Science courses, especially in computer programming. In this thesis, XML plagiarism detection model is introduced and XML is used as an intermediate data exchange mechanism in the suggested model. Since a procedural programming language is defined by its specific rules and it is well-structured form, we can generate an XML document from a program source based on the XML schema. As long as we can generate XML documents from given program sources, XML queries to extract information how they are similar to each other can be queried over the documents. This idea makes us encourage to moving our attention to plagiarism detection models. As the result of this study, XML Plagiarism Detection System (XPDec) has been developed. The plagiarism detection systems for programming can be classified into two main groups: attribute-counting based systems and structural metrics based systems. XPDec system uses the combined detection mechanism. In addition to the mechanism, XPDec system is adopting the XML query language suggested in XML plagiarism detection model to extract control sequences from XML documents. This mechanism increases the accuracy of the results. At the end of this thesis we shows that the XPDec system gives high accuracy results to finding similarities among the given source programs

A parametric prototype for spatiotemporal databases

The main goal of this project is to design and implement the parametric database (ParaDB). Conceptually, ParaDB consists of the parametric data model (ParaDM) and the parametric structured query language (ParaSQL). Parametric data model is a data model for multi-dimensional databases such as temporal, spatial, spatiotemporal, or multi-level secure databases. Main difference compared to the classical relational data model is that ParaDM models an object as a single tuple, and an attribute is defined as a function from parametric elements. The set of parametric elements is closed under union, intersection, and complementation. These operations are counterparts of or, and, and not in a natural language like English. Therefore, the closure properties provide very flexible ways to query on objects without introducing additional self-join operations which are frequently required in other multi-dimensional database models

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

Efficient Self-Join Algorithm in Interval-based Temporal Data Models

Interval-based temporal data model is a popular data model in temporal databases. It uses time intervals for representing the period of validity of a tuple, leading to unavoidable self-joins when combining tuples for objects. It requires k+1-way self-join for k conjunctive conditions. Join operations are one of the most expensive operations in databases and they are even more serious in temporal databases because of growing data. There are many join algorithms for temporal databases. However, they focus on joining different inputs rather than an identical input, leading to multiple scans for the identical input. Advanced 2-way join algorithms avoid a quadratic disk I/O complexity, but they are affected by the number of self-joins and partition sizes. In this paper, we address the problem of self-joins in the interval-based temporal data model and introduce a stream-based self-join algorithm. The proposed algorithm shows that it achieves a single relation scan for k-way self-join and its performance is not affected by partition sizes

RAST: Requirement Analysis Support Tool based on Linguistic Information

Requirement specifications written in natural language might cause miscommunication among developers depending on how they are understood. Without removing any ambiguities, we cannot construct systems satisfying the need for software safety. Removing ambiguities should be performed in early steps during the development. In this paper, Requirement Analysis Support Tool (RAST) will be introduced. RAST system analyzes requirement specifications based on linguistic information. By using RAST system, we can expect that requirement engineers can communicate with each other in common notations, and use logical expressions rather than using requirement specifications written in natural language

Query-friendly Compression and Indexing of Recurring Structures in XML Documents

XML documents are by design self-describing. In order to accomplish this, the XML data is highly verbose and very repetitious. Although techniques already exist to compress XML and text in general, most do not keep the data in a form that is useful to users. We present a technique that makes use of recurring structures within an XML document to compress the file in a way that can achieve better compression than other query-friendly compression techniques while still maintaining the data in a form that allows for both querying and indexing. Further, we present an example implementation of the technique, complete with an index-building mechanism and query processing capabilities

Association Between Visceral Fat and Brain Cortical Thickness in the Elderly: A Neuroimaging Study

BackgroundDespite emerging evidence suggesting that visceral fat may play a major role in obesity-induced neurodegeneration, little evidence exists on the association between visceral fat and brain cortical thickness in the elderly.PurposeWe aimed to examine the association between abdominal fat and brain cortical thickness in a Korean elderly population.MethodsThis cross-sectional study included elderly individuals without dementia (n = 316). Areas of visceral fat and subcutaneous fat (cm2) were estimated from computed tomography scans. Regional cortical thicknesses (mm) were obtained by analyzing brain magnetic resonance images. Given the inverted U-shaped relationship between visceral fat area and global cortical thickness (examined using a generalized additive model), visceral fat area was categorized into quintiles, with the middle quintile being the reference group. A generalized linear model was built to explore brain regions associated with visceral fat. The same approach was used for subcutaneous fat.ResultsThe mean (standard deviation) age was 67.6 (5.0) years. The highest quintile (vs. the middle quintile) group of visceral fat area had reduced cortical thicknesses in the global [β = –0.04 mm, standard error (SE) = 0.02 mm, p = 0.004], parietal (β = –0.04 mm, SE = 0.02 mm, p = 0.01), temporal (β = –0.05 mm, SE = 0.02 mm, p = 0.002), cingulate (β = –0.06 mm, SE = 0.02 mm, p = 0.01), and insula lobes (β = –0.06 mm, SE = 0.03 mm, p = 0.02). None of the regional cortical thicknesses significantly differed between the highest and the middle quintile groups of subcutaneous fat area.ConclusionThe findings suggest that a high level of visceral fat, but not subcutaneous fat, is associated with a reduced cortical thickness in the elderly