Sap Se

Korea University Research and Business Foundation

Seungho Yoo

Yong Sik Kwon

Hyeong Seog Kim

Ji Hoon Jang

Hwangnam Kim

Seyeong Bae

Suk Kyu Lee

Methods, systems, and computer-readable storage media for receiving a first storage request indicating a first type of data and a first size, identifying a first sub-space based on the first type, the first sub-space including a dense group of dense segments and a sparse group of sparse segments, and determining that the dense group of the first sub-space is absent a dense segment to store data of the first storage request based on the first size, and in response: determining whether the sparse group of the first sub-space includes a sparse segment to store the data of the first storage request based on the first size, and storing the data of the first storage request to the sparse group of the first sub-space in response to determining that the sparse group of the first sub-space includes a sparse segment to store the data of the first storage request.

Memory allocation and deallocation mechanism to reduce fragmentation and enhance defragmentation performance

Methods, systems, and computer-readable storage media for online defragmentation of memory in database systems by applying an IX-lock to each table having data stored in a marked page in a set of marked pages, generating a record map including key-value pairs, each being associated with a record location in a marked page, a value of each key-value pair initially set to a first value, iteratively executing the online defragmentation to delete data from marked pages and add the data to non-sparse pages, at least one iteration including applying a try-lock to a record in a marked page, and at iterations of the online defragmentation, updating the record map to change the value of at least one key-value pair from the first value to the second value, the second value representing that data of a marked page has been deleted from the marked page and added to a non-sparse page.

Efficient and non-disruptive online defragmentation with record locking

An image encoding apparatus and method and an image decoding apparatus and method are disclosed. The image encoding method may include extracting a ROI from an input image, determining a compression rate of a remaining region excluding the ROI of the image based on a network state between the image transmitting apparatus and the image receiving apparatus, and encoding the remaining region based on the compression rate.

Method and apparatus for encoding image and method and apparatus for decoding image

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Seoul, South Korea

Seungho Yoo