Papers by Prabhdeep Singh
Default α Logic for Modeling Customizable Failure Semantics in Workflow Systems Using Dynamic Reconfiguration Constraints
In this paper, we propose a logic based framework to handle failures that occur during the execut... more In this paper, we propose a logic based framework to handle failures that occur during the execution of workflows by encoding the failures in formalism of a default normal modal logic. Default logic provides a set of rules for adding premises to logical arguments. Since the specifications of services are encoded in α-logic, defaults can be added to this logic to accommodate the failure semantics for the predicates. We encode predicate failures as predicates and provide a dynamic proof system that handles failures at the execution time. Workflow adaptations are re-synthesized from proofs in our logic using a Curry-Howard style correspondence.
Default alpha-Logic for Modeling Customizable Failure Semantics in Workflow Systems Using Dynamic Reconfiguration Constraints
In this paper, we propose a logic based framework to handle failures that occur during the execut... more In this paper, we propose a logic based framework to handle failures that occur during the execution of workflows by encoding the failures in formalism of a default normal modal logic. Default logic provides a set of rules for adding premises to logical arguments. Since the specifications of services are encoded in α-logic, defaults can be added to this logic to accommodate the failure semantics for the predicates. We encode predicate failures as predicates and provide a dynamic proof system that handles failures at the execution time. Workflow adaptations are re-synthesized from proofs in our logic using a Curry-Howard style correspondence.
Life scientists spend significant time browsing public online data websites to identify and retri... more Life scientists spend significant time browsing public online data websites to identify and retrieve information relevant to ongoing investigations, particularly new updates regarding functions associated with specific genes, the annotation of genetic variations of genes (alleles, single nucleotide polymorphisms [SNPs]), and patterns of expression of genes. Some of this activity is exploratory to identify new paths to information, however major components of web searching activity amounts to repetitive work gathering updates from the data sources to keep the investigator current with a rapidly moving, multidisciplinary arena of science. Because these queries of public and private repositories inform ongoing empiric research, the investigator is mandated to attempt to stay current with the expanding and evolving databases that are fueled by contributions from other scientists in very diverse disciplines.
We propose an inexpensive and scalable approach for curation that takes advantage of automatic in... more We propose an inexpensive and scalable approach for curation that takes advantage of automatic information extraction methods as a starting point, and is based on the premise that if there are a lot of articles, then there must be a lot of readers and authors of these articles. Thus we provide a mechanism by which the readers of the articles can participate and collaborate in the curation of information.
Default α Logic for Modeling Customizable Failure Semantics in Workflow Systems Using Dynamic Reconfiguration Constraints
In this paper, we propose a logic based framework to handle failures that occur during the execut... more In this paper, we propose a logic based framework to handle failures that occur during the execution of workflows by encoding the failures in formalism of a default normal modal logic. Default logic provides a set of rules for adding premises to logical arguments. Since the specifications of services are encoded in α-logic, defaults can be added to this logic to accommodate the failure semantics for the predicates. We encode predicate failures as predicates and provide a dynamic proof system that handles failures at the execution time. Workflow adaptations are re-synthesized from proofs in our logic using a Curry-Howard style correspondence.
WinAgent is a software system for creating and executing Personal Information Assistants (PIAs). ... more WinAgent is a software system for creating and executing Personal Information Assistants (PIAs). These are software robots that can locate and extract targeted data buried deep within a web site. They do so by automatically navigating to relevant sites, locating the correct Web pages (which can be either directly accessed by traversing appropriate links or by filling out HTML forms), and extracting, structuring, and organizing data of interest from these pages into XML. The primary thrust of WinAgent technology effort was to make these tools easy-to-use by users who are not necessarily trained in computing. In particular users create and execute PIAs through a Web Browser.
Default alpha-Logic for Modeling Customizable Failure Semantics in Workflow Systems Using Dynamic Reconfiguration Constraints
In this paper, we propose a logic based framework to handle failures that occur during the execut... more In this paper, we propose a logic based framework to handle failures that occur during the execution of workflows by encoding the failures in formalism of a default normal modal logic. Default logic provides a set of rules for adding premises to logical arguments. Since the specifications of services are encoded in α-logic, defaults can be added to this logic to accommodate the failure semantics for the predicates. We encode predicate failures as predicates and provide a dynamic proof system that handles failures at the execution time. Workflow adaptations are re-synthesized from proofs in our logic using a Curry-Howard style correspondence.
Life scientists spend significant time browsing public online data websites to identify and retri... more Life scientists spend significant time browsing public online data websites to identify and retrieve information relevant to ongoing investigations, particularly new updates regarding functions associated with specific genes, the annotation of genetic variations of genes (alleles, single nucleotide polymorphisms [SNPs]), and patterns of expression of genes. Some of this activity is exploratory to identify new paths to information, however major components of web searching activity amounts to repetitive work gathering updates from the data sources to keep the investigator current with a rapidly moving, multidisciplinary arena of science. Because these queries of public and private repositories inform ongoing empiric research, the investigator is mandated to attempt to stay current with the expanding and evolving databases that are fueled by contributions from other scientists in very diverse disciplines.
International Journal of Web Services Research, 2007
Service-based systems have many applications, such as e-business, health care, and homeland secur... more Service-based systems have many applications, such as e-business, health care, and homeland security. In these systems, it is necessary to provide users the capability of composing services into workflows providing higher-level functionality. In dynamic service-oriented computing environments, it is desirable that service composition is automated and situation-aware to generate robust and adaptive workflows. In this paper, an automated situation-aware service composition approach is presented. This approach is based on the a-logic, a-calculus, and a declarative model for situation awareness (SAW). This approach consists of four major components: (1) analyzing SAW requirements using our SAW model, (2) translating our SAW model representation to a-logic specifications and specifying a control flow graph in a-logic as the service composition goal, (3) automated synthesis of a-calculus terms defining situation-aware workflow agents based on a-logic specifications for SAW requirements and the control flow graph, and (4) compilation of a-calculus terms to executable components.
We propose an inexpensive and scalable approach for curation that takes advantage of automatic in... more We propose an inexpensive and scalable approach for curation that takes advantage of automatic information extraction methods as a starting point, and is based on the premise that if there are a lot of articles, then there must be a lot of readers and authors of these articles. Thus we provide a mechanism by which the readers of the articles can participate and collaborate in the curation of information.
Workflows tend to fail in real-world scenarios due to the uncertain/unreliable sensory informatio... more Workflows tend to fail in real-world scenarios due to the uncertain/unreliable sensory information which sometimes needs to be updated during the execution of workflows. In a logic based framework, these dynamic predicates that can be updated are called non-monotonic predicates (NMPs). In this paper, we focus on reducing the risk of a given workflow due to the NMPs in that workflow. The main idea is to synthesize a backup workflow by augmenting the main workflow without introducing new NMPs. The backup workflow is generated by using expected values of NMPs if necessary instead of given values. The expected values are calculated from the execution history or provided by a domain expert. It is argued that total risk reduces to the square root of the main workflow itself.
WinAgent is a software system for creating and executing Personal Information Assistants (PIAs). ... more WinAgent is a software system for creating and executing Personal Information Assistants (PIAs). These are software robots that can locate and extract targeted data buried deep within a web site. They do so by automatically navigating to relevant sites, locating the correct Web pages (which can be either directly accessed by traversing appropriate links or by filling out HTML forms), and extracting, structuring, and organizing data of interest from these pages into XML. The primary thrust of WinAgent technology effort was to make these tools easy-to-use by users who are not necessarily trained in computing. In particular users create and execute PIAs through a Web Browser.
We often realize that communicating with other colleagues who are studying similar topics helps t... more We often realize that communicating with other colleagues who are studying similar topics helps to identify information relevant to our area of study, which otherwise may not have been found. We wish to accelerate acquisition of collective knowledge in a defined area by identifying specific spheres of inquiry. Such spheres correspond to groups of people who are experts in a field. In this paper we provide a systematic way to gain knowledge from their online search activity, and enable them to organize and share their search findings for further analysis. We have built a prototype system, BioLog, to help biomedical researchers share this implicit knowledge among their peers and store their access patterns into a central system for reuse. BioLog has been deployed it in two labs within TGen as a pilot study. The data has been gathered and analyzed by preliminary text-mining and collaborative filtering methods.
Creating Personal Information Assistants for Targeted Navigation and Extraction via a Web Browser
ABSTRACT A Personal Information Assistant (PIA) is a software robot that a user deploys to retrie... more ABSTRACT A Personal Information Assistant (PIA) is a software robot that a user deploys to retrieve targeted data from Web sources that he/she is interested in. A PIA automatically navigates to relevant sites, locates the correct Web pages (which can be either directly accessed by traversing appropriate links or by filling out HTML forms), and extracts, structures, and organizes the data from these pages into presentation formats specified by the user. In this paper we describe techniques for empowering the end user (who is not ...
International Journal of Web Services Research, 2007
Service-based systems have many applications, such as e-business, health care, and homeland secur... more Service-based systems have many applications, such as e-business, health care, and homeland security. In these systems, it is necessary to provide users the capability of composing services into workflows providing higher-level functionality. In dynamic service-oriented computing environments, it is desirable that service composition is automated and situation-aware to generate robust and adaptive workflows. In this paper, an automated situation-aware service composition approach is presented. This approach is based on the a-logic, a-calculus, and a declarative model for situation awareness (SAW). This approach consists of four major components: (1) analyzing SAW requirements using our SAW model, (2) translating our SAW model representation to a-logic specifications and specifying a control flow graph in a-logic as the service composition goal, (3) automated synthesis of a-calculus terms defining situation-aware workflow agents based on a-logic specifications for SAW requirements and the control flow graph, and (4) compilation of a-calculus terms to executable components.
Workflows tend to fail in real-world scenarios due to the uncertain/unreliable sensory informatio... more Workflows tend to fail in real-world scenarios due to the uncertain/unreliable sensory information which sometimes needs to be updated during the execution of workflows. In a logic based framework, these dynamic predicates that can be updated are called non-monotonic predicates (NMPs). In this paper, we focus on reducing the risk of a given workflow due to the NMPs in that workflow. The main idea is to synthesize a backup workflow by augmenting the main workflow without introducing new NMPs. The backup workflow is generated by using expected values of NMPs if necessary instead of given values. The expected values are calculated from the execution history or provided by a domain expert. It is argued that total risk reduces to the square root of the main workflow itself.
We often realize that communicating with other colleagues who are studying similar topics helps t... more We often realize that communicating with other colleagues who are studying similar topics helps to identify information relevant to our area of study, which otherwise may not have been found. We wish to accelerate acquisition of collective knowledge in a defined area by identifying specific spheres of inquiry. Such spheres correspond to groups of people who are experts in a field. In this paper we provide a systematic way to gain knowledge from their online search activity, and enable them to organize and share their search findings for further analysis. We have built a prototype system, BioLog, to help biomedical researchers share this implicit knowledge among their peers and store their access patterns into a central system for reuse. BioLog has been deployed it in two labs within TGen as a pilot study. The data has been gathered and analyzed by preliminary text-mining and collaborative filtering methods.
Creating Personal Information Assistants for Targeted Navigation and Extraction via a Web Browser
ABSTRACT A Personal Information Assistant (PIA) is a software robot that a user deploys to retrie... more ABSTRACT A Personal Information Assistant (PIA) is a software robot that a user deploys to retrieve targeted data from Web sources that he/she is interested in. A PIA automatically navigates to relevant sites, locates the correct Web pages (which can be either directly accessed by traversing appropriate links or by filling out HTML forms), and extracts, structures, and organizes the data from these pages into presentation formats specified by the user. In this paper we describe techniques for empowering the end user (who is not ...
Stylistic text can be found on sign boards, street and organizations boards and logos, bulletin b... more Stylistic text can be found on sign boards, street and organizations boards and logos, bulletin boards, announcements, advertisements, dangerous goods plates, warning notices, etc. In stylistic text images, text-lines within an image may have different orientations such as curved in shape or not be parallel to each other. As a result, extraction and subsequent recognition of individual text-lines and words in such images is a difficult task. In this paper, we propose a novel scheme for straightening of curved text-lines using the concept of dilation, flood-fill, robust thinning, and B-spline curve-based fitting. In the proposed scheme, at first, dilation is applied on individual text-lines to cover the area within a certain boundary. Next, thinning is applied to get the path of the text, approximate the path using the B-spline, find the angle between the normal at a point on the curve and the vertical line, and finally visit each point on the text and rotate by their corresponding angles. The proposed methodology is tested on variety of text images containing text-lines in Devanagari, English, and Chinese scripts which is evaluated on the basis of visual perception and the mean square error (MSE) calculation. MSE is calculated by line fitting applied on input and output images. On the basis of evaluation results obtained in our experiments, the proposed method is promising.
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Papers by Prabhdeep Singh