Integration and querying of heterogeneous, autonomous, distributed database systems

Today, databases have become an integral part of information systems. In the past two decades, we have seen different database systems being developed independently and used in different applications domains. Today's interconnected networks and advanced applications, such as data warehousing, data mining & knowledge discovery and intelligent data access to information on the Web, have created a need for integrated access to such heterogeneous, autonomous, distributed database systems. Heterogeneous/multidatabase research has focused on this issue resulting in many different approaches. However, a single, generally accepted methodology in academia or industry has not emerged providing ubiquitous intelligent data access from heterogeneous, autonomous, distributed information sources. ^ This thesis describes a heterogeneous database system being developed at High-performance Database Research Center (HPDRC). A major impediment to ubiquitous deployment of multidatabase technology is the difficulty in resolving semantic heterogeneity. That is, identifying related information sources for integration and querying purposes. Our approach considers the semantics of the meta-data constructs in resolving this issue. The major contributions of the thesis work include: (i) providing a scalable, easy-to-implement architecture for developing a heterogeneous multidatabase system, utilizing Semantic Binary Object-oriented Data Model (Sem-ODM) and Semantic SQL query language to capture the semantics of the data sources being integrated and to provide an easy-to-use query facility; (ii) a methodology for semantic heterogeneity resolution by investigating into the extents of the meta-data constructs of component schemas. This methodology is shown to be correct, complete and unambiguous; (iii) a semi-automated technique for identifying semantic relations, which is the basis of semantic knowledge for integration and querying, using shared ontologies for context-mediation; (iv) resolutions for schematic conflicts and a language for defining global views from a set of component Sem-ODM schemas; (v) design of a knowledge base for storing and manipulating meta-data and knowledge acquired during the integration process. This knowledge base acts as the interface between integration and query processing modules; (vi) techniques for Semantic SQL query processing and optimization based on semantic knowledge in a heterogeneous database environment; and (vii) a framework for intelligent computing and communication on the Internet applying the concepts of our work. ^

Integration and querying of heterogeneous, autonomous, distributed database systems

Today, databases have become an integral part of information systems. In the past two decades, we have seen different database systems being developed independently and used in different applications domains. Today's interconnected networks and advanced applications, such as data warehousing, data mining & knowledge discovery and intelligent data access to information on the Web, have created a need for integrated access to such heterogeneous, autonomous, distributed database systems. Heterogeneous/multidatabase research has focused on this issue resulting in many different approaches. However, a single, generally accepted methodology in academia or industry has not emerged providing ubiquitous intelligent data access from heterogeneous, autonomous, distributed information sources. This thesis describes a heterogeneous database system being developed at Highperformance Database Research Center (HPDRC). A major impediment to ubiquitous deployment of multidatabase technology is the difficulty in resolving semantic heterogeneity. That is, identifying related information sources for integration and querying purposes. Our approach considers the semantics of the meta-data constructs in resolving this issue. The major contributions of the thesis work include: (i.) providing a scalable, easy-to-implement architecture for developing a heterogeneous multidatabase system, utilizing Semantic Binary Object-oriented Data Model (Sem-ODM) and Semantic SQL query language to capture the semantics of the data sources being integrated and to provide an easy-to-use query facility; (ii.) a methodology for semantic heterogeneity resolution by investigating into the extents of the meta-data constructs of component schemas. This methodology is shown to be correct, complete and unambiguous; (iii.) a semi-automated technique for identifying semantic relations, which is the basis of semantic knowledge for integration and querying, using shared ontologies for context-mediation; (iv.) resolutions for schematic conflicts and a language for defining global views from a set of component Sem-ODM schemas; (v.) design of a knowledge base for storing and manipulating meta-data and knowledge acquired during the integration process. This knowledge base acts as the interface between integration and query processing modules; (vi.) techniques for Semantic SQL query processing and optimization based on semantic knowledge in a heterogeneous database environment; and (vii.) a framework for intelligent computing and communication on the Internet applying the concepts of our work.

A Cross-Generational Analysis of Spanish-to-English Lexico-Semantic Phenomena in Emerging Miami English

Sociolinguists have documented the substrate influence of various languages on the formation of dialects in numerous ethnic-regional setting throughout the United States. This literature shows that while phonological and grammatical influences from other languages may be instantiated as durable dialect features, lexical phenomena often fade over time as ethnolinguistic communities assimilate with contiguous dialect groups. In preliminary investigations of emerging Miami Latino English, we have observed that lexical forms based on Spanish lexical forms are not only ubiquitous among the speech of the first generation Cuban Americans but also of the second. Examples, observed in field work, casual observation, and studied formally in an experimental context include the following: “get down from the car,” which derives from the Spanish equivalent, bajar del carro instead of “get out of the car”. The translation task administered to thirty-one participants showed a variety lexical phenomena are still maintained at equal or higher frequencies.

A semantic paradigm for intelligent data access

An implementation of Sem-ODB—a database management system based on the Semantic Binary Model is presented. A metaschema of Sem-ODB database as well as the top-level architecture of the database engine is defined. A new benchmarking technique is proposed which allows databases built on different database models to compete fairly. This technique is applied to show that Sem-ODB has excellent efficiency comparing to a relational database on a certain class of database applications. A new semantic benchmark is designed which allows evaluation of the performance of the features characteristic of semantic database applications. An application used in the benchmark represents a class of problems requiring databases with sparse data, complex inheritances and many-to-many relations. Such databases can be naturally accommodated by semantic model. A fixed predefined implementation is not enforced allowing the database designer to choose the most efficient structures available in the DBMS tested. The results of the benchmark are analyzed. ^ A new high-level querying model for semantic databases is defined. It is proven adequate to serve as an efficient native semantic database interface, and has several advantages over the existing interfaces. It is optimizable and parallelizable, supports the definition of semantic userviews and the interoperability of semantic databases with other data sources such as World Wide Web, relational, and object-oriented databases. The query is structured as a semantic database schema graph with interlinking conditionals. The query result is a mini-database, accessible in the same way as the original database. The paradigm supports and utilizes the rich semantics and inherent ergonomics of semantic databases. ^ The analysis and high-level design of a system that exploits the superiority of the Semantic Database Model to other data models in expressive power and ease of use to allow uniform access to heterogeneous data sources such as semantic databases, relational databases, web sites, ASCII files, and others via a common query interface is presented. The Sem-ODB engine is used to control all the data sources combined under a unified semantic schema. A particular application of the system to provide an ODBC interface to the WWW as a data source is discussed. ^

A conceptual framework for understanding contemporary child slavery

This thesis developed a conceptual framework aimed at enhancing our understanding of contemporary child slavery. A new variety of slavery exists today, the result of forms of forced servitude that existed alongside slavery many centuries ago. This is tantamount to slavery. There is, however, a critical lack of awareness about important aspects of the reality of this new child slavery. The framework and definitions of slavery in usage today, though interesting and sufficient to cover historical situations, are unable to adequately describe the conditions of the child slavery. Using existing literature and research, this thesis conceptualized children's labor in a manner that allows a clearer perception of the exploitation of their labor within and beyond the household. Explanatory factors such as culture, the age of victims, the number of hours worked and the ability or not of the victim to volunteer or withdraw their participation in the specific activities were employed to determine if particular situations should be considered as child slavery, repressive child labor or merely as child work. Important distinctions were made between the use of children's mental and physical energy in defined activities. ^

A study of dual cultures in dyadic relations

Elderly caregiving, a fact of life for millions of Americans, has gained significance with the increase in the elderly population. Over 25 million family caregivers in the US, most of whom are women rearing their own children, care for severely ill or disabled family members. The increased flow of women into the labor force has caused this traditional role to be entrusted to hired caregivers, mainly home health aides. ^ This case study describes and explains the dyadic experiences of elderly Jewish clients and their Jamaican home health aides in a mixed-culture environment. The inquiry was conducted with a purposive sample of four dyads, their case manager, and the placement officer, all of whom were selected through a home care agency in Fort Lauderdale, Florida. Strategies of data collection including non-participant observation, interviews, document analysis, and researcher's journals. Data from verbatim transcription of interviews and field notes were coded, sorted into emic categories, and reduced as linkages were identified via cross-case comparison. Three major themes—mixed-culture experiences, relationship building and maintenance, and agency role perceptions—emerged from the interpretative analysis of the data. ^ Assertions from these findings include that dyads have established a range of relationships to meet their personal needs, expectations, and desires in these goal-driven relationships. Relationally, they have reached interactional synchrony with some achieving the ideal family-type bond. Cultural difference is but one of the many contextual variables in the home care environment, which has its own cultural norms and expectations. Conflicts transcend cultural difference and seemed more a factor of individual relational disposition. ^

On the developmental continuity /discontinuity of early adolescent patterns of racial identity salience: Relations with later identities and psychosocial adjustment

Given the significant amount of attention placed upon race within our society, racial identity long has been nominated as a meaningful influence upon human development (Cross, 1971; Sellers et al., 1998). Scholars investigating aspects of racial identity have largely pursued one of two lines of research: (a) describing factors and processes that contribute to the development of racial identities, or (b) empirically documenting associations between particular racial identities and key adjustment outcomes. However, few studies have integrated these two approaches to simultaneously evaluate developmental and related adjustment aspects of racial identity among minority youth. Consequently, relations between early racial identity developmental processes and correlated adjustment outcomes remain ambiguous. Even less is known regarding the direction and function of these relationships during adolescence. To address this gap, the present study examined key multivariate associations between (a) distinct profiles of racial identity salience and (b) adjustment outcomes within a community sample of African-American youth. Specifically, a person-centered analytic approach (i.e., cluster analysis) was employed to conduct a secondary analysis of two archived databases containing longitudinal data measuring levels of racial identity salience and indices of psychosocial adjustment among youth at four different measurement occasions.^ Four separate groups of analyses were conducted to investigate (a) the existence of within-group differences in levels of racial identity salience, (b) shifts among distinct racial identity types between contiguous times of measurement, (c) adjustment correlates of racial identity types at each time of measurement, and (d) predictive relations between racial identity clusters and adjustment outcomes, respectively. Results indicated significant heterogeneity in patterns of racial identity salience among these African-American youth as well as significant discontinuity in the patterns of shifts among identity profiles between contiguous measurement occasions. In addition, within developmental stages, levels of racial identity salience were associated with several adjustment outcomes, suggesting the protective value of high levels of endorsement or internalization of racial identity among the sampled youth. Collectively, these results illustrated the significance of racial identity salience as a meaningful developmental construct in the lives of African-American adolescents, the implications of which are discussed for racial identity and practice-related research literatures. ^

The World Trade Organization, competition policy, and developing countries: A cross -country examination of domestic policy actions

This dissertation addresses the following research question: in a particular policy area, why do countries that display unanimity in their international policy behavior diverge from each other in their domestic policy actions? I address this question in the context of the divergent domestic competition policy actions undertaken by developing countries during the period 1996-2007, after these countries had quite conspicuously displayed near-unanimity in opposing this policy measure at the World Trade Organization (WTO). This divergence is puzzling because (a) it does not align with their near-unanimous behavior at the WTO over competition policy and (b) it is at variance with the objectives of their international opposition to this policy at the WTO. Using an interdisciplinary approach, this dissertation examines the factors responsible for this divergence in the domestic competition policy actions of developing countries. ^ The theoretical structure employed in this study is the classic second-image-reversed framework in international relations theory that focuses on the domestic developments in various countries following an international development. Methodologically, I employ both quantitative and qualitative methods of analysis to ascertain the nature of the relationship between the dependent variable and the eight explanatory variables that were identified from existing literature. The data on some of the key variables used in this dissertation was uniquely created over a multi-year period through extensive online research and represents the most comprehensive and updated dataset currently available. ^ The quantitative results obtained from logistic regression using data on 131 countries point toward the significant role played by international organizations in engineering change in this policy area in developing countries. The qualitative analysis consisting of three country case studies illuminate the channels of influence of the explanatory variables and highlight the role of domestic-level factors in these three carefully selected countries. After integrating the findings from the quantitative and qualitative analyses, I conclude that a mix of international- and domestic-level variables explains the divergence in domestic competition policy actions among developing countries. My findings also confirm the argument of the second-image-reversed framework that, given an international development or situation, the policy choices that states make can differ from each other and are mediated by domestic-level factors. ^

Semantic Categorization in Portuguese-English Bilinguals

The main purpose of this study was to investigate the cross-linguistic interactions in the semantic categorization of late Portuguese-English bilinguals. The lexical items used in this study have a wider range of applications in one language and narrower in the other. Three types of categories were examined: classical, homophones, and radials. Late Portuguese-English bilinguals, as well as Portuguese and English monolinguals, were tested. After hearing a word, participants were asked to choose from a set of images, one that could be labelled as such. Analyses showed that when tested in English, participants performed better when it was the wider language. Participants’ performance was lower on classical categories than on homophone and radial categories.