Conceptual knowledge (or semantic knowledge) refers to our shared knowledge for words, objects, people and emotions. The anterior temporal lobes (ATLs) have been identified as a critical region for the representation of conceptual knowledge through convergent evidence from fMRI in healthy participants, cortical electrode implantation and damage-deficit correlations. With the involvement of the ATLs established, recent research has begun to focus on the functions of subregions of the ATLs - with particular interest surrounding the functions of the left and right ATLs. This thesis investigated three main research questions: (1) What are the functions of the left and right ATLs in semantic representation? (2) How does unilateral damage affect the semantic system and what mechanisms underlie the robustness of the system? (3) Do functional gradations exist within the ATLs? These questions were addressed using convergent methodologies including functional neuroimaging and transcranial magnetic stimulation (TMS) in healthy participants and behavioural and neuroimaging investigations in patients who have undergone unilateral ATL resection. To address the question of left vs. right ATL function, this thesis began by directly comparing the predictions of the different accounts of ATL function in a large-scale meta-analysis of the existing neuroimaging literature (Chapter 2) and in a large sample of patients who had undergone unilateral left or right ATL resection (Chapter 3). The overarching finding was that conceptual knowledge is underpinned by a primarily bilateral ATL system, whereby both the left and right ATLs are critical for normal semantic processing. Secondary to this bilateral representation, relative functional gradations were observed both between and within the ATLs. To address the second research question, Chapter 4 investigated the robustness of the semantic system to unilateral damage, specifically regions involved in the maintenance of conceptual knowledge were localised. Results showed that upregulation occurred within regions previously associated with semantic knowledge. The upregulation of activation after unilateral resection also mimicked the upregulation in control participants during more challenging semantic processing. Chapter 5 examined the behavioural relevance of upregulation in the contralateral ATL after unilateral perturbation using a novel TMS protocol in healthy participants. The findings observed here suggest that the bilateral ATL system is resistant to a degree of unilateral damage/perturbation because semantic representations are distributed between the hemispheres. Therefore, unilateral damage/disruption only results in a mild semantic impairment, as the undamaged/unperturbed hemisphere is available to compensate. Finally, Chapter 6 explored functional gradations within the ATLs by comparing responses in the ventral ATL to different conceptual categories, presented as visual and auditory inputs. The functional gradations observed here are proposed to emerge via differential structural and functional connectivity between the ATLs and sensory-motor and limbic cortices.

Thesis (M.S.)--Washington State University, December 2007. / Includes bibliographical references (p. 66-69).

Web aggregation has been available regionally for several years, but this service has not been offered globally. As an example, using multiple regional comparison aggregators, we analyze the global prices for a Sony camcorder, which differ by more than three times. We further explain that lack of global comparison aggregation services partially contribute to such huge price dispersion. We also discuss difficulties encountered in the manual integration of global web sources. Motivated by this example, we propose a context mediation architecture for global aggregation to address semantic disparities of global information sources. Global aggregation services can bring efficiency to the global market and can be useful for market research and other business uses. / Singapore-MIT Alliance (SMA)

This Master’s thesis presents an algorithm that finds the semantic differences between two versions of files, an older version and a new modified version of the file. The algorithm is responsible for finding changes in the program’s behavior and displaying them graphically. By this a lot of time can be saved because it is not necessary to go through the whole file to find the differences.   The program, Semantic Diff, developed in this master thesis uses the Javacc parser generator which is used to parse files and generate the abstract syntax tree for them. Using this tree it is possible to see all the methods, classes, constructors and parameters for both older version and modified version.  By comparing all the methods, classes and interfaces of both the versions it is possible to find the differences that change the program behavior.   The algorithm for finding semantic differences has been evaluated by testing it on various test cases. By making changes in the original file and in the modified file. Like adding methods and deleting methods and adding classes to the files. The algorithm highlights those methods with green color which are added newly in the modified file and highlights the methods with red color in the original file which got deleted in modified file. This algorithm also finds the textual difference between two files and highlights those lines which are changed in modified file and which got deleted from original file.

The current study provides evidence for the dissociation between two types of asymmetries in relations within semantic memory: those due to unidirectional associative strength (e.g., Kahan, Neely & Forsythe, 1999), and the inherent asymmetry of causal relations (e.g., Fenker, Waldmann & Holyoak, 2005). By manipulating the stimulus onset asynchrony (SOA) in a relation recognition task, I demonstrate that expectancy differentially impacts the effects of these asymmetries. An asymmetrical directional response time advantage was seen with causal relations at both long (1000 ms) and short (150 ms) SOAs, but only at long SOAs for unidirectional associates. These data are taken to support the hypothesis that latencies due to unidirectional association are a result of the manner in which these relations are accessed, and latencies due to the asymmetry of causal relations are reflective of the manner in which cause-effect asymmetries are represented.

Information collection and discovery tasks involve aggregation and manipulation of information resources. An information resource is a location from which a human gathers data to contribute to his/her understanding of something significant. Repositories of information resources include the Google search engine, the ACM Digital Library, Wikipedia, Flickr, and IMDB. Information discovery tasks involve having new ideas in contexts of information collecting. The information one needs to collect is large and diverse and hard to keep track of. The heterogeneity and scale also make difficult writing software to support information collection and discovery tasks. Metadata is a structured means for describing information resources. It forms the basis of digital libraries and search engines. As metadata is often called, "data about data," we define meta-metadata as a formal means for describing metadata as an XML based language. We consider the lifecycle of metadata in information collection and discovery tasks and develop a metametadata architecture which deals with the data structures for representation of metadata inside programs, extraction from information resources, rules for presentation to users, and logic that defines how an application needs to operate on metadata. Semantic actions for an information resource collection are steps taken to generate representative objects, including formation of iconographic image and text surrogates, associated with metadata. The meta-metadata language serves as a layer of abstraction between information resources, power users, and application developers. A power user can enhance an existing collection visualization application by authoring meta-metadata for a new information resource without modifying the application source code. The architecture provides a set of interfaces for semantic actions which different information discovery and visualization applications can implement according to their own custom requirements. Application developers can modify the implementation of these semantic actions to change the behavior of their application, regardless of the information resource. We have used our architecture in combinFormation, an information discovery and collection visualization application and validated it through a user study.

<p>This Master’s thesis presents an algorithm that finds the semantic differences between two versions of files, an older version and a new modified version of the file. The algorithm is responsible for finding changes in the program’s behavior and displaying them graphically. By this a lot of time can be saved because it is not necessary to go through the whole file to find the differences.</p><p> </p><p>The program, Semantic Diff, developed in this master thesis uses the Javacc parser generator which is used to parse files and generate the abstract syntax tree for them. Using this tree it is possible to see all the methods, classes, constructors and parameters for both older version and modified version.  By comparing all the methods, classes and interfaces of both the versions it is possible to find the differences that change the program behavior.</p><p> </p><p>The algorithm for finding semantic differences has been evaluated by testing it on various test cases. By making changes in the original file and in the modified file. Like adding methods and deleting methods and adding classes to the files. The algorithm highlights those methods with green color which are added newly in the modified file and highlights the methods with red color in the original file which got deleted in modified file. This algorithm also finds the textual difference between two files and highlights those lines which are changed in modified file and which got deleted from original file.</p><p> </p>

Thesis (M.S.)--Brigham Young University. Dept. of Computer Science, 2003. / Includes bibliographical references (p. 65-69).

Zugl.: Karlsruhe, Univ., Diss., 2009

Graduate