Abstract: Methods and compositions for treating Gaucher disease are described.

Abstract: Methods and compositions for treating Gaucher disease are described.

Abstract: An apparatus for protecting computer memory utilizes a parity matrix to generate an n-k check bit signal of an extended linear (n,k,4) code from a k data bit signal. Exclusive-OR gates add the n-k check bit signal to an n-k tag bit signal selected from a predetermined class, to form, when concatenated with the k data bit signal, an element of a code of a certain class. The element comprising the k data bit signal is written in memory. A correction matrix or And gate cooperating with exclusive-OR gates detects an attempt to access the k data bit signal with an n-k key bit signal belonging to the same class as the n-k tag bit signal, but which does not match it.

Abstract: An address sequencer utilizes binary words generated by Exclusive-OR addition of Gray code words to linear code words to produce a sequence of computer or memory addresses such that the addresses whose indices lie within a selected range of the index of a particular address are a predetermined Hamming distance from that address, whereby the possibility of recent data being overwritten is reduced.

Abstract: A ternary magnetic recording system wherein groups of binary input digits are transformed into corresponding groups of ternary recording code symbols utilizing a hierarchical code substitution system in which the longest valid group in the code is encoded. The code substitution system provides retention of the advantageous properties of a prior ternary recording system while significantly enhancing the automatic gain control utilized in amplitude discrimination between two of the ternary recording symbols. Anomalous detection of chained doublets is also obviated. Data recovery is effected by decoding apparatus utilizing an eight bit addressable ROM addressed with a twelve bit ternary word.

Abstract: Apparatus and method for encoding binary data in a ternary format including ternary 0, ternary 1 and ternary 2 code symbols. In a preferred embodiment of the invention utilized for magnetic data storage, a ternary 0 is represented by the absence of signal change, a ternary 1 is represented by a single transition and a ternary 2 is represented by a pulse or pair of closely spaced transitions. Further features of the invention provide for merging ternary code symbols so as to prevent the spacing between adjacent symbols from becoming so small as to create undesirable crowding, and inserting and shifting symbols to prevent the spacing between adjacent symbols from becoming so great as to adversely affect recovery of the encoded data.

Abstract: A compressor parses the input data stream into segments where each segment comprises a prefix and the next symbol in the data stream following the prefix. The prefix of a segment is the longest match with a previously parsed segment of the data stream. The compressor constructs a search tree data base to effect the parsing and to generate a pointer for each segment pointing to the previous segment matching the prefix. The search tree comprises internal nodes including a root and external nodes denoted as leaves. The nodes are interconnected by branches representative of symbols of the alphabet. Each parsed segment of the input data is represented by a path from the root to a leaf. The tree is adaptively constructed from the input data such that as each new segment is parsed, one new internal node of the tree is created from a leaf and new leaves are defined, one for each symbol already encountered by the encoder plus an additional branch to represent all potential but unseen symbols.

Abstract: A method and apparatus for encoding binary data in a data stream so as to increase the number of data bits represented by one transition, such as a transition recorded on a magnetic medium, and thereby increase the storage density. The data stream is converted into words each having m bits. Two of the data words are stored so as to be simultaneously accessible to a converting system that converts the data words into code words wherein each code word has n bits. In the invention, m/n=2/3. In order to increase the space between adjacent transitions, the conversion is carried out according to a scheme wherein all code words have at least one binary ONE and lack successive binary ONEs except certain cases in which a code word is converted to all ZEROs to avoid ONEs in the nth bit of a given code word and the first bit of the code word following the given code word. Also described is a decoding method and apparatus for recovering the encoded data and decoding it to the original binary data.

Abstract: The invention is described in the environment of a binary data magnetic recording and reproducing system and comprises a binary to non-consecutive zero code converter for encoding the input binary data into a non-consecutive zero code which, in turn, is recorded on the magnetic medium. In recording, a flux transition occurs for each ONE of the non-consecutive zero code. A bipolar peak detector detects the flux transitions and thus detects the presence of the recorded ONEs. The peak detected signals are utilized to continuously trigger a mono-stable multivibrator having a period whereby the multivibrator relaxes to its stable state in the absence of a ONE which denotes the presence of a ZERO. The peak detected signal and the output of the mono-stable multivibrator are utilized to synthesize a clock signal from the recorded non-consecutive zero data.