Yun T Chi, Age ~46Dublin, CA

7788264, Aug 31, 2010

Oct 10, 2007

11/869899

Kai Yu - Cupertino CA,
Yun Chi - Santa Clara CA,
Yihong Gong - Saratoga CA,

NEC Laboratories America, Inc. - Princeton NJ

G06F 17/30

707739, 706 20

Systems and methods for classifying documents each having zero or more links thereto include generating a link matrix; generating a document term matrix; and jointly factorizing the document term matrix and the link matrix.

2012010, May 3, 2012

Oct 1, 2011

13/251215

Pengcheng Xiong - Cupertino CA,
Yun Chi - Monte Sereno CA,
Junichi Tatemura - Cupertino CA,
Vahit Hakan Hacigumus - San Jose CA,

NEC LABORATORIES AMERICA, INC. - Princeton NJ

G06N 7/02

706 52

An admission control system for a cloud database includes a machine learning prediction module to estimate a predicted probability for a newly arrived query with a deadline, if admitted into the cloud database, to finish its execution before said deadline, wherein the prediction considers query characteristics and current system conditions. The system also includes a decision module applying the predicted probability to admit a query into the cloud database with a target of profit maximization with an expected profit determined using one or more service level agreements (SLAs).

2013027, Oct 17, 2013

Apr 3, 2013

13/855765

Yun Chi - Monte Sereno CA,
Vahit Hakan Hacigumus - San Jose CA,

NEC Laboratories America, Inc. - Princeton NJ

G06F 17/30

707654

A method for balancing database workloads among a plurality of database servers includes when a new server is available, selecting a set of master and slave databases to be migrated to the new server; and migrating the selected databases to result in a balanced new workload among all servers while minimizing migration cost; and during operation, if workload unbalance is detected in real time from a workload change in a certain database, iteratively selecting one database at a time to migrate to a different server to balance the workload.

2013022, Aug 29, 2013

Dec 11, 2012

13/711023

Yun Chi - Monte Sereno CA,
Junichi Tatemura - Morrisville PA,
Vahit Hakan Hacigumus - San Jose CA,

NEC Laboratories America, Inc. - Princeton NJ

G06F 17/30

707719

There are provided a system and method for predicting query execution time in a database system. A cost model determination device determines a cost model of a database query optimizer for the database system. The cost model models costs of queries applied to the database system. A profiling device determines profiling queries for profiling input/output cost units and processor cost units relating to the database system, and profiles the cost units using the profiling queries to output profiled cost units. A calibrating device calibrates cost units in the cost model responsive to the profiled cost units to output calibrated cost units. A sampling re-estimator samples and re-estimates a cardinality estimation of a final query plan to output an updated cardinality estimation. A predictor applies the calibrated cost units and the updated cardinality estimation in the cost model to generate a prediction of an execution time of a given query.

2013021, Aug 15, 2013

Nov 21, 2012

13/683849

Hyun Jin Moon - Newark CA,
Yun Chi - Monte Sereno CA,
Vahit Hakan Hacigumus - San Jose CA,

NEC Laboratories America, Inc. - Princeton NJ

G06F 17/30

707609

Systems and methods for consolidating workload on one or more computing devices, comprising: generating tenant performance profiles for at least one of a buffer memory size and a buffer warmness; assigning one or more tenants to a database management system (DBMS) instance; configuring the one or more tenants to minimize a total server count needed to host the one or more tenants; and reducing the total server count by adjusting of buffer sizes while satisfying Service Level Agreement (SLA) requirements.

2013016, Jun 27, 2013

Jun 16, 2012

13/525308

Hyun Jin MOON - NEWARD CA,
Yun CHI - MONTE SERENO CA,
Vahit Hakan HACIGUMUS - SAN JOSE CA,

NEC Laboratories America, Inc. - Princeton NJ

H04L 12/24

709226

A computer implemented method of workload scheduling under two different types of Service Level Agreements (SLAs), namely soft and hard SLA which employ both a deadline- and cost-aware scheduler called iCBS-DH. The scheduler is evaluated against deadline and cost performance of various scheduling policies under a large range of SLA cost function and deadline types.

2013008, Apr 4, 2013

Oct 4, 2012

13/645103

Yun Chi - Monte Sereno CA,
Hyun Jin Moon - Newark CA,
Vahit Hakan Hacigumus - San Jose CA,

NEC Laboratories America, Inc. - Princeton NJ

G06F 17/30
G06F 12/16

707649, 707E17005

Methods and systems for database migration from a multitenant database include taking a snapshot of an original database to be migrated with a hot backup process, such that the database is still capable of answering queries during the hot backup process; maintaining a query log of all queries to the tenant database after the hot backup process begins; initializing a new database at a target server using the snapshot; replaying the query log synchronize the new database with the original database; and answering new queries with the new database and not the original database.

2013008, Apr 4, 2013

Oct 4, 2012

13/645112

Yun Chi - Monte Sereno CA,
Hyun Jin Moon - Newark CA,
Vahit Hakan Hacigumus - San Jose CA,

NEC Laboratories America, Inc. - Princeton NJ

G06F 9/455

703 22

A method for migration from a multitenant database is shown that includes building an analytical model for each of a set of migration methods based on database characteristics; predicting performance of the set of migration methods using the respective analytical model with respect to tenant service level agreements (SLAs) and current and predicted tenant workloads, where the prediction includes a migration speed and an SLA violation severity; and selecting a best migration method from the set of migration methods according to the respective predicted migration speeds and SLA violation severities.