Abstract: A memory controller for controlling a memory device including a plurality of pages is provided. The memory controller comprises: an input data controller configured to receive data to be stored in a page selected from among the plurality of pages; a sequence information generator configured to generate sequence information indicating a sequential order of a program operation of storing the data in the first page based on sequential orders of program operations performed before the program operation; and a write operation controller configured to control the memory device to store the data in a first area of the first page and to store history information in a second area of the first page, wherein the history information includes a physical address of the first page and the sequence information corresponding to the data.

Abstract: A memory controller for controlling a memory device including a plurality of pages is provided. The memory controller comprises: an input data controller configured to receive data to be stored in a page selected from among the plurality of pages; a sequence information generator configured to generate sequence information indicating a sequential order of a program operation of storing the data in the first page based on sequential orders of program operations performed before the program operation; and a write operation controller configured to control the memory device to store the data in a first area of the first page and to store history information in a second area of the first page, wherein the history information includes a physical address of the first page and the sequence information corresponding to the data.

Abstract: A system for controlling voltage unbalance in a direct current distribution system includes a measurement processor configured to measure a positive load current, and a negative load current at a first load point, including a first load connected to a positive line and a neutral line and a second load connected to the neutral line and a negative line, and at a second load point in a power distribution system; and a control processor configured to determine whether to activate a first load point switching signal based on the positive and negative load currents at the first and second load points to control the first load point to switch the connections of the first load and the second load between the positive line and the negative line.

Abstract: An apparatus and method for controlling adaptive reclosing based on transient stability of a power transmission line are disclosed. The apparatus includes a power angle calculation unit, an integral square error (ISE) second-order differential calculation unit, a stability determination unit, and a disconnection signal generation unit. The power angle calculation unit acquires the instantaneous value of a power angle based on voltage and phase angle measurement signals. The ISE second-order differential calculation unit acquires the instantaneous value of the second-order differential of the ISE of the power angle. The stability determination unit determines whether a system is stable or unstable based on the transitions in the instantaneous value of the second-order differential of the ISE.

Abstract: A system for controlling voltage unbalance in a direct current distribution system includes a measurement processor configured to measure a positive load current, and a negative load current at a first load point, including a first load connected to a positive line and a neutral line and a second load connected to the neutral line and a negative line, and at a second load point in a power distribution system; and a control processor configured to determine whether to activate a first load point switching signal based on the positive and negative load currents at the first and second load points to control the first load point to switch the connections of the first load and the second load between the positive line and the negative line.

Abstract: An apparatus and method for controlling adaptive reclosing based on transient stability of a power transmission line are disclosed. The apparatus includes a power angle calculation unit, an integral square error (ISE) second-order differential calculation unit, a stability determination unit, and a disconnection signal generation unit. The power angle calculation unit acquires the instantaneous value of a power angle based on voltage and phase angle measurement signals. The ISE second-order differential calculation unit acquires the instantaneous value of the second-order differential of the ISE of the power angle. The stability determination unit determines whether a system is stable or unstable based on the transitions in the instantaneous value of the second-order differential of the ISE.

Abstract: An apparatus for compressing and decompressing data is disclosed. The apparatus for compressing data includes a block setting unit that divides data of at least one original file into two or more blocks, a compression unit that generates block compression data by applying a compression algorithm to data corresponding to at least one block among blocks divided by the block setting unit, and a compression file generation unit that generates a block header and the block body of the block for each block divided by the block setting unit, in which the block body includes the block compression data if the block is compressed by the compression unit or includes the original data of the block if the block is not compressed the by compression unit.

Abstract: A forward compatibility guaranteed data compression and decompression method and apparatus are provided. The compressed data decompression apparatus includes a compressed file parsing unit which parses a compressed file comprising compressed data, a header including information on the compressed data and an extension field to extract the compressed data, and an original file generating unit which decompresses the compressed data to generate an original file. The extension field includes one or more extension field units and an extension field terminating code indicating an end of a region capable of including the extension field units, each of the header and the extension field units starts with a data identification code having the same number of bytes, and the extension field unit further includes its own length data separated by a predetermined number of bytes from its own data identification code.

Abstract: An apparatus for compressing and decompressing data is disclosed. The apparatus for compressing data includes a block setting unit that divides data of at least one original file into two or more blocks, a compression unit that generates block compression data by applying a compression algorithm to data corresponding to at least one block among blocks divided by the block setting unit, and a compression file generation unit that generates a block header and the block body of the block for each block divided by the block setting unit, in which the block body includes the block compression data if the block is compressed by the compression unit or includes the original data of the block if the block is not compressed the by compression unit.

Abstract: A forward compatibility guaranteed data compression and decompression method and apparatus are provided. The compressed data decompression apparatus includes a compressed file parsing unit which parses a compressed file comprising compressed data, a header including information on the compressed data and an extension field to extract the compressed data, and an original file generating unit which decompresses the compressed data to generate an original file. The extension field includes one or more extension field units and an extension field terminating code indicating an end of a region capable of including the extension field units, each of the header and the extension field units starts with a data identification code having the same number of bytes, and the extension field unit further includes its own length data separated by a predetermined number of bytes from its own data identification code.

Abstract: Disclosed herein is a data compression method for improving a compression rate when compressing computer data by employing both a method of generating a character string dictionary and storing indexes and a method of storing compression codes corresponding to character strings. Accordingly, a compression rate and a decompression speed increase.