International Business Machines Corporation

Seoul Semiconductor Co., Ltd.

Jae Gil Lee

Vijayshankar Raman

Guy Maring Lohman

Ronald Jason Barber

Richard Sefton Sidle

Sam Sampson Lightstone

Lin Qiao

Min-Soo Kim

Young Do Jong

Ho Young Cha

Kwan Hyun Lee

June Sik Kwak

Bong Ryeol Park

A system joins predicate evaluated column bitmaps having varying lengths. The system includes a column unifier for querying column values with a predicate generating an indicator bit for each of the column values that is then joined with the respective column value. The system also includes a bitmap generator for creating a column-major linear bitmap from the column values and indicator bits. The column unifier also determines an offset between adjacent indicator bits. The system also includes a converter for multiplying the column-major linear bitmap with a multiplier to shift the indicator bits into consecutive positions in the linear bitmap.

Multiplication-based method for stitching results of predicate evaluation in column stores

A system joins predicate evaluated column bitmaps having varying lengths. The system includes a column unifier for querying column values with a predicate and generating an indicator bit for each of the column values that is then joined with the respective column value. The system also includes a bitmap generator for creating a column-major linear bitmap from the column values and indicator bits. The column unifier also determines an offset between adjacent indicator bits. The system also includes a converter for multiplying the column-major linear bitmap with a multiplier to shift the indicator bits into consecutive positions in the linear bitmap.

Exemplary embodiments of the present invention disclose a unidirectional heterojunction transistor including a channel layer made of a first nitride-based semiconductor having a first energy bandgap, a barrier layer made of a second nitride-based semiconductor having a second energy bandgap different from the first energy bandgap, the barrier layer including a recess, a drain electrode disposed on a first region of the barrier layer, and a recessed-drain Schottky electrode disposed in the recess of the barrier layer, the recessed-drain Schottky electrode contacting the drain electrode.

Nitride semiconductor device and method of manufacturing the same

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Daejeon, South Korea

Jae Gil Lee