Patents by Inventor Ravishankar Ramamurthy
Ravishankar Ramamurthy has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7685194Abstract: Fine-grained access control for querying a database with low overhead and safety plans. In a view placement approach, base relations of the query expression are replaced by views that are appropriate for the particular user. Information leakage via UDF pushing, exception processing, and error messages can be prevented by generating safe plans. An existing query optimizer can be modified to perform redundancy removal and safe plan implementation. Subsumption testing available in materialized view matching can be exploited by the query optimizer. Authorization inference is exploited to generate safe plans.Type: GrantFiled: August 31, 2006Date of Patent: March 23, 2010Assignee: Microsoft CorporationInventors: Govind Kabra, Ravishankar Ramamurthy, Sundararajarao Sudarshan
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Patent number: 7637107Abstract: A control system and method that compensates for changes in backpressure of an engine includes a pressure sensor that senses the backpressure. A boost compensation module that communicates with the pressure sensor, determines an averaged BC factor, and adjusts a variable geometry turbo based on the averaged BC factor.Type: GrantFiled: July 24, 2006Date of Patent: December 29, 2009Assignee: GM Global Technology Operations, Inc.Inventor: Ravishankar Ramamurthy
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Publication number: 20090254522Abstract: A database server may be configured to compute distinct page counts of pages accessed to execute operands of respective queries. The queries may be executed against a table comprised of the pages and having an index managed by the database server. The distinct page counts may be obtained by counting, as a part of the executing of the queries, distinct pages accessed during the execution of the queries.Type: ApplicationFiled: April 4, 2008Publication date: October 8, 2009Applicant: MICROSOFT CORPORATIONInventors: Surajit Chaudhuri, Vivek Narasayya, Ravishankar Ramamurthy
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Publication number: 20090183508Abstract: A turbocharger protection system for an engine system that includes a particulate filter and a turbocharger comprises a delta pressure estimator that estimates a pressure difference in a particulate filter. A pressure factor estimator module estimates a pressure factor based on the difference and barometric pressure. A fuel limit estimator module protects the turbocharger by selectively limiting fuel injection to the engine based on the pressure factor.Type: ApplicationFiled: March 6, 2008Publication date: July 23, 2009Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventor: Ravishankar Ramamurthy
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Publication number: 20090094191Abstract: A proactive monitoring mechanism for correcting the choice of access methods (available query plans) for a given query, based on execution feedback from the same query. The mechanism exploits bypassing predicate short-circuiting inside the database server's predicate evaluation module to obtain expression cardinalities. The mechanism can also modify a plan to obtain expression cardinalities. These techniques are used judiciously by the query optimizer and/or a database administrator (DBA) so that the execution overheads are within acceptable limits.Type: ApplicationFiled: October 8, 2007Publication date: April 9, 2009Applicant: MICROSOFT CORPORATIONInventors: Surajit Chaudhuri, Vivek R. Narasayya, Ravishankar Ramamurthy
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Publication number: 20090083238Abstract: Stop-and-restart query execution that partially leverages the work already performed during the initial execution of the query to reduce the execution time during a restart. The technique selectively saves information from a previous execution of the query so that the overhead associated with restarting the query execution can be bounded. Despite saving only limited information, the disclosed technique substantially reduces the running time of the restarted query. The stop-and-restart query execution technique is constrained to save and reuse only a bounded number of records (intermediate records or output records) thereby releasing all other resources, rather than some of the resources. The technique chooses a subset of the records to save that were found during normal execution and then skipping the corresponding records when performing a scan during restart to prevent the duplication of execution. A skip-scan operator is employed to facilitate the disclosed restart technique.Type: ApplicationFiled: September 21, 2007Publication date: March 26, 2009Applicant: MICROSOFT CORPORATIONInventors: Surajit Chaudhuri, Shriraghav Kaushik, Abhijit Pol, Ravishankar Ramamurthy
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Patent number: 7493337Abstract: A query progress indicator that provides an indication to a user of the progress of a query being executed on a database. The indication of the progress of the query allows the user to decide whether the query should be allowed to complete or should be aborted. One method that may be used to estimate the progress of a query that is being executed on a database defines a model of work performed during execution of a query. The total amount of work that will be performed during execution of the query is estimated according to the model. The amount of work performed at a given point during execution of the query is estimated according to the model. The progress of the query is estimated using the estimated amount of work at the given point in time and the estimated total amount of work. This estimated progress of query execution may be provided to the user.Type: GrantFiled: March 31, 2004Date of Patent: February 17, 2009Assignee: Microsoft CorporationInventors: Surajit Chaudhuri, Vivek Narasayya, Ravishankar Ramamurthy
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Patent number: 7454407Abstract: Techniques for estimating the progress of database queries are described herein. In a first implementation, a respective lower-bound parameter is associated with each node in an operator tree that representing a given database query, and the progress of the database query at a given point is estimated based upon the lower-bound parameters. In a second implementation, the progress of the query is estimated by associating respective lower-bound and upper-bound parameters with each node in the operator tree. The progress of the query at the given point is then estimated based on the lower-bound and upper-bound parameters.Type: GrantFiled: June 10, 2005Date of Patent: November 18, 2008Assignee: Microsoft CorporationInventors: Surajit Chaudhuri, Ravishankar Ramamurthy, Kaushik Shriraghav
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Patent number: 7437874Abstract: A method for controlling exhaust gas particulate emissions from a compression ignition internal combustion engine having a variable geometry turbocharger (VGT) includes the steps of determining backpressure across the engine and air mass flow into the engine, closing vanes of the VGT to provide air mass flow increase when backpressure is increasing, and stopping the step of closing the vanes of the VGT when a decrease in rate of change of air mass flow is determined.Type: GrantFiled: March 10, 2005Date of Patent: October 21, 2008Assignee: Detroit Diesel CorporationInventors: Ravishankar Ramamurthy, Laurentiu Vaduva, Admir Krejo
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Publication number: 20080177694Abstract: Database systems use a plan cache to avoid the overheads (e.g., time, money) of query recompilation. Query plans can become invalidated by updates to the statistics on data or changes to the physical database design. Once a plan is invalidated, it can be repaired utilizing one or more of the disclosed embodiments. Incremental repair of query plans includes reusing parts of the current plan rather than discarding the plan entirely when it is invalidated. Repair to an existing query plan is attempted before resorting to full recompilation.Type: ApplicationFiled: January 19, 2007Publication date: July 24, 2008Applicant: MICROSOFT CORPORATIONInventors: Surajit Chaudhuri, Ravishankar Ramamurthy
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Publication number: 20080071785Abstract: Fine-grained access control for querying a database with low overhead and safety plans. In a view placement approach, base relations of the query expression are replaced by views that are appropriate for the particular user. Information leakage via UDF pushing, exception processing, and error messages can be prevented by generating safe plans. An existing query optimizer can be modified to perform redundancy removal and safe plan implementation. Subsumption testing available in materialized view matching can be exploited by the query optimizer. Authorization inference is exploited to generate safe plans.Type: ApplicationFiled: August 31, 2006Publication date: March 20, 2008Applicant: MICROSOFT CORPORATIONInventors: Govind Kabra, Ravishankar Ramamurthy, Sundararajarao Sudarshan
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Publication number: 20080016865Abstract: A control system and method that compensates for changes in backpressure of an engine includes a pressure sensor that senses the backpressure. A boost compensation module that communicates with the pressure sensor, determines an averaged BC factor, and adjusts a variable geometry turbo based on the averaged BC factor.Type: ApplicationFiled: July 24, 2006Publication date: January 24, 2008Inventor: Ravishankar Ramamurthy
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Publication number: 20060288701Abstract: A method for controlling exhaust gas particulate emissions from a compression ignition internal combustion engine having a variable geometry turbocharger (VGT) includes the steps of determining backpressure across the engine and air mass flow into the engine, closing vanes of the VGT to provide air mass flow increase when backpressure is increasing, and stopping the step of closing the vanes of the VGT when a decrease in rate of change of air mass flow is determined.Type: ApplicationFiled: March 10, 2005Publication date: December 28, 2006Applicant: Detroit Diesel CorporationInventors: Ravishankar Ramamurthy, Laurentiu Vaduva, Admir Kreso
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Publication number: 20060282404Abstract: Techniques for estimating the progress of database queries are described herein. In a first implementation, a respective lower-bound parameter is associated with each node in an operator tree that representing a given database query, and the progress of the database query at a given point is estimated based upon the lower-bound parameters. In a second implementation, the progress of the query is estimated by associating respective lower-bound and upper-bound parameters with each node in the operator tree. The progress of the query at the given point is then estimated based on the lower-bound and upper-bound parameters. The progress estimate is computed by dividing the work done so far by the sums of the above averages for each node in the tree.Type: ApplicationFiled: June 10, 2005Publication date: December 14, 2006Applicant: Microsoft CorporationInventors: Surajit Chaudhuri, Ravishankar Ramamurthy, Kaushik Shriraghav
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Patent number: 7079938Abstract: A control and method for an internal combustion engine that includes an exhaust gas recirculation system to predict an intake manifold critical temperature (dew point) at which condensation would occur upon entry into exhaust gas recirculation. The control calculates the intake manifold critical temperature (IMT_Critical) as a function of predetermined, sensed or assumed values by processing an equation whose variables are occupied by the values. The control commands adjustments of exhaust gas recirculation operation in response to the calculation, preferably after the actual intake manifold temperature exceeds the IMT_Critical for a predetermined time.Type: GrantFiled: July 25, 2003Date of Patent: July 18, 2006Assignee: Detroit Diesel CorporationInventors: Sameer Bhargava, Ravishankar Ramamurthy, Laurentiu Vaduva
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Publication number: 20050222965Abstract: A query progress indicator that provides an indication to a user of the progress of a query being executed on a database. The indication of the progress of the query allows the user to decide whether the query should be allowed to complete or should be aborted. One method that may be used to estimate the progress of a query that is being executed on a database defines a model of work performed during execution of a query. The total amount of work that will be performed during execution of the query is estimated according to the model. The amount of work performed at a given point during execution of the query is estimated according to the model. The progress of the query is estimated using the estimated amount of work at the given point in time and the estimated total amount of work. This estimated progress of query execution may be provided to the user.Type: ApplicationFiled: March 31, 2004Publication date: October 6, 2005Inventors: Surajit Chaudhuri, Vivek Narasayya, Ravishankar Ramamurthy
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Patent number: 6934621Abstract: A control for an internal combustion engine that includes an exhaust gas recirculation system predicts at least one of the intake manifold temperature in EGR mode or an intake manifold pressure in EGR mode, but preferably both, during Boost mode operation. The predictions are relied upon to calculate an intake manifold critical temperate in EGR, at which condensation would occur. The control then compares the predicted temperate value with the calculated intake manifold critical temperature, and if the predicted value exceeds the calculated temperature, the control commands re-entry into exhaust gas recirculation mode.Type: GrantFiled: July 25, 2003Date of Patent: August 23, 2005Assignee: Detroit Diesel CorporationInventors: Sameer Bhargava, Ravishankar Ramamurthy, Brian A. Lewallen
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Publication number: 20050021217Abstract: A control for an internal combustion engine that includes an exhaust gas recirculation system predicts at least one of the intake manifold temperature in EGR mode or an intake manifold pressure in EGR mode, but preferably both, during Boost mode operation. The predictions are relied upon to calculate an intake manifold critical temperate in EGR, at which condensation would occur. The control then compares the predicted temperate value with the calculated intake manifold critical temperature, and if the predicted value exceeds the calculated temperature, the control commands re-entry into exhaust gas recirculation mode.Type: ApplicationFiled: July 25, 2003Publication date: January 27, 2005Applicant: DETROIT DIESEL CORPORATIONInventors: Sameer Bhargava, Ravishankar Ramamurthy, Brian Lewallen
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Publication number: 20050021218Abstract: A control and method for an internal combustion engine that includes an exhaust gas recirculation system to predict an intake manifold critical temperature (dew point) at which condensation would occur upon entry into exhaust gas recirculation. The control calculates the intake manifold critical temperature (IMT_Critical) as a function of predetermined, sensed or assumed values by processing an equation whose variables are occupied by the values. The control commands adjustments of exhaust gas recirculation operation in response to the calculation, preferably after the actual intake manifold temperature exceeds the IMT_Critical for a predetermined time.Type: ApplicationFiled: July 25, 2003Publication date: January 27, 2005Inventors: Sameer Bhargava, Ravishankar Ramamurthy, Laurentiu Vaduva
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Patent number: 6725848Abstract: An exhaust gas recirculation system for a compression ignition engine is provided wherein the exhaust gas recirculation is shut off depending upon the sensed or calculated humidity in the intake manifold relative to the dew point of the exhaust/intake air mixture. The humidity of the exhaust/intake air mixture may be measured in the intake manifold, charge air mixer or the ambient humidity may be sensed. If humidity is measured in the air charge mixer or in the ambient air, other factors such as engine speed and load, intake manifold pressure, EGR flow and air/fuel ratio may be used to calculate the humidity in the intake manifold. When the temperature of the mixture in the intake manifold is less than the dew point of the mixture, the engine control strategy may be shut off the EGR to prevent condensation in the exhaust gas recirculation system or engine.Type: GrantFiled: January 18, 2002Date of Patent: April 27, 2004Assignee: Detroit Diesel CorporationInventors: Ravishankar Ramamurthy, Sameer Bhargara, Phillip F. Rimnac