Abstract: Methods and systems for improved data transmission using audio transmissions are provided. In one embodiment, a method is provided that includes receiving an audio transmission at. Audio symbols may be identified within the audio transmission, and a magnitude and phase for each of the symbols may be identified. Based on the magnitudes and phases, corresponding data values may be identified for each of the audio symbols and may be combined to form a data payload of the audio transmission.

Abstract: The present invention provides an information recording configuration that achieves both difficulty in reading and highly accurate reading. Highly confidential additional information such as encryption key is recorded in a groove signal. During recording of the additional information, a groove signal is recorded that has an amplitude offset setting commensurate with the bit value. During reading of the additional information, a signal R0 with no offset is estimated from a signal R1 read from the groove signal for a predetermined period, after which a difference signal C=R1?R0 is calculated and integrated for each of the predetermined periods so as to determine the direction of the amplitude offset for each period. This process achieves recording and reproduction of additional information that offers enhanced difficulty in reading and highly accurate reading at the same time.

Abstract: An encoding device for converting m-bit data words into n-bit (both n and m are integers and 2n?2m×2) code words includes a first encoding table in which 2m code words selected from the 2n n-bit code words correspond to 2m m-bit data words, a second encoding table in which 2m code words, which do not overlap with the code words in the first encoding table, of the 2n n-bit code words correspond to 2m m-bit data words, and an encoding unit which selects and outputs a code word, in which an absolute value of a code string DSV is smaller, from code words corresponding to the input m-bit data words in the first encoding table and code words corresponding to the input m-bit data words in the second encoding table.

Abstract: An information recording processing constitution realizing both readout difficulty and high-precision readout is provided. Superimposition recording of highly secret additional information such as a cryptographic key in a groove signal recorded on a disk, which superimposition recording realizes both readout difficulty and high-precision readout, can be performed. The groove signal to which a phase error corresponding to a bit value is set is recorded at a time of recording of the additional information, and at a time of readout of the additional information, the phase error of the groove signal in a predetermined section is subjected to an integrating process and the direction of the phase error of the groove signal within each section is determined. The recording and reproduction of the additional information for increasing readout difficulty and realizing high-precision readout is realized by such processes.

Abstract: A recording and reproducing area and a reproduction-only area are formed by wobbling a groove formed in a spiral fashion to form a track to be tracked on a disk. The recording and reproducing area has address information recorded by wobbling of the groove and information recorded and reproduced by phase change marks on the track formed by the groove where the address information is recorded. The reproduction-only area has prerecorded information recorded by wobbling of the groove.

Abstract: A recording and reproducing area and a reproduction-only area are formed by wobbling a groove formed in a spiral fashion to form a track to be tracked on a disk. The recording and reproducing area has address information recorded by wobbling of the groove and information recorded and reproduced by phase change marks on the track formed by the groove where the address information is recorded. The reproduction-only area has prerecorded information recorded by wobbling of the groove.

Abstract: A ROM disk having a block data format provided with linking areas as with a rewritable disk. Main data recorded in a main data area and linking data recorded in a linking area in each block are scrambled by identical scrambling data. The scrambling data is generated by a random sequence using address information of the block as an initial value.

Abstract: Method and apparatus for writing repeating patterns of features to a substrate, such as a data storage medium. In accordance with some embodiments, a multi-dimensional pattern of discrete features of different sizes to be written to a substrate is divided into a plurality of contiguous regions. A unique set of compensation values is assigned to each region. A write beam of a write system is used to write the features to the substrate responsive to said unique sets of compensation values so that all of the features having a common size in at least one region are written using the same compensation values from the associated set.

Abstract: A player is provided that is capable of playing discs of either a first or a second configuration. Both types of discs can be double-sided optical discs formed with data tracks. In one configuration, the tracks on one side follow one spiral while the tracks on the other side follow a second spiral, the two spirals being oriented in opposite directions as viewed from the respective sides, and therefore being mirror images of each other. This allows data to be read by a player seamlessly from both sides of the disc without changing the direction of rotation of the disc. In the other configuration, the tracks follow identical spirals. The disc is then rotated in one direction for one side and the other direction for the other side.

Abstract: Recording mark forming method utilizing a device including a laser and a laser drive carried by a pickup having a movement drive wherein a control controls the drives to irradiate a recording medium with laser pulse sequences to form recording marks having recording mark lengths between a predetermined and maximum lengths, a top section, a last section including a cooling period, and an intermediate period. Heat of mark front edges is controlled by top section recording parameters classified according to recording mark lengths and recording parameters of first through maximum recording mark lengths are classified into a same group. Heat of mark rear edges is controlled by cooling start positions for cooling periods classified according to recording mark lengths. Cooling start positions for a second predetermined mark length through the maximum mark length are classified into a same group. The second mark length is longer than the first mark length.

Abstract: A method of applying image data as a visually detectable pattern with at least one embedded data element at an optical record carrier is disclosed, comprising the step of physically mapping at least one channel symbol onto the record carrier, the channel symbol being selected from a set of mutually different channel symbols, the channel symbols each comprising an area of size s1 with a relatively low value v1 for an optical property and an area with size s2 with a relatively high value v2 for said optical property, the channel symbols being distributed over a plurality of subsets each having a plurality of channel symbols wherein the plurality of channel symbols within a subset have a distance that is substantially less than the distance between channel symbols of mutually different subsets, wherein the distance between two channel symbols is defined as the absolute difference between the ratios s1/(s1+s2).

Abstract: An optical disk recording method includes the steps of: providing a multi-pulse chain from a recording wave; independently changing the pulse rise timing and pulse fall timing (pulse width) of the first pulse in the multi-pulse chain in accordance with a preceding space length and a recording mark length; changing the pulse rise timing and pulse fall timing (pulse width) in accordance with a following space length and the recording mark length in a predetermined timing or in independence; and in relation to the smallest mark recorded by irradiation with mono pulse, changing the rise timing in accordance with the preceding space length and the recording mark length and the fall timing (pulse width) in accordance with the following space length and recording mark length, compensating various optical disks different in recording material without change of the fundamental waveform.

Abstract: An optical disc drive according to the present invention writes information on an optical disc, which includes a substrate on which a number of pre-pits have been formed on its tracks and a recording film that is supported on the substrate. The optical disc drive includes a writing control section for instructing an optical pickup to record marks on the tracks by irradiating the recording film with a writing light beam. In accordance with information that defines, on the tracks, recordable areas Aa1 through Aa4 where the marks are recordable and pre-pit reading areas Ab1 through Ab4 where no marks are recordable, the writing control section controls the optical pickup so that the marks are recorded on at least some of the recordable areas. On the tracks on which the marks are recorded, each recordable area is shorter than any of the pre-pit reading areas.

Abstract: Provided herein are hybrid laser diode drivers (LDDs) that drive a laser diode in response to receiving enable signals from a controller. In accordance with specific embodiments, a hybrid LDD includes a read channel to selectively output a read current, one or more write channel each to selectively output a write current, and an oscillator channel to selectively output an oscillator current. Additionally, in specific embodiments the hybrid LDD includes a state machine that receives the enable signals from the controller, and based on the enable signals, controls timing of the currents output by the read, write and oscillator channels.

Abstract: A method and apparatus for stably encoding/decoding data, and a method and apparatus for recording/reproducing data are disclosed. The method inserts decoding information into a data section including several predetermined-bit data, determines encoding values of the data according to a transition state of the data and a value of corresponding data, and generates the decoding information and the determined encoding values in units of the data section.

Abstract: A recording device for recording data on a rewritable optical record carrier (11). The device comprises recording means (21, 22, 25) for forming marks on the record carrier during recording operations by irradiating the record carrier with a radiation beam (24), the marks representing the data. Further, the device comprises control means (20) for controlling the recording operations and beam control means (31) for controlling a write power of the radiation beam with reference to an optimum write power by changing the write power within a predetermined write power range around the optimum write power for subsequent write cycles, each of the write cycles comprising at least one recording operation. Variation of the write power improves the overwrite quality, in particular, in the management area, such as the file system area.

Abstract: A hybrid LDD includes a read channel to selectively output a read current, a plurality of write channels, each to selectively output a different write current, and an oscillator channel to selectively output an oscillator current. Additionally, the hybrid LDD includes programmable LDD controller that receives the plurality of enable signals from the external controller, and based on the enable signals, controls timing of the currents output by at least the write channels. The programmable LDD controller can also control timing of the currents output by the read and oscillator channels, based on the enable signals. Further and alternative embodiments are also provided.

Abstract: An encoding device for converting m-bit data words into n-bit (both n and m are integers and 2n?2m×2) code words includes a first encoding table in which 2m code words selected from the 2n n-bit code words correspond to 2m m-bit data words, a second encoding table in which 2m code words, which do not overlap with the code words in the first encoding table, of the 2n n-bit code words correspond to 2m m-bit data words, and an encoding unit which selects and outputs a code word, in which an absolute value of a code string DSV is smaller, from code words corresponding to the input m-bit data words in the first encoding table and code words corresponding to the input m-bit data words in the second encoding table.

Abstract: An encoding apparatus that converts m-bit data words into n-bit code words, where m and n are both integers and satisfy an expression 2n?2m×2, includes a first conversion table in which 2m m-bit data words are associated with 2m n-bit code words selected from 2n n-bit code words, a second conversion table in which the 2m m-bit data words are associated with 2m n-bit code words that have been selected from the 2n n-bit code words and that do not overlap with the 2m n-bit code words in the first conversion table, and an encoder configured to select and output an n-bit code word with which an m-bit data word that has been input is associated in the first conversion table or an n-bit code word with which the m-bit data word that has been input is associated in the second conversion table, the selected and output n-bit code word having a smaller number of symbols “1”.

Abstract: An optical storage medium can be provided by which illegal usage of the optical storage medium involving an infringement on the copyright can be prevented effectively without impairment of the functions for reproducing physical format information and optical storage medium manufacturing information. The optical storage medium includes a main information region in which encrypted data information is recorded as a pit row that is capable of being read out by means of light and a control data region. In the control data region, key information for decoding the encryption of the data information, the physical format information and the optical storage medium manufacturing information are recorded by wobbling a groove.

Abstract: A hybrid LDD includes a read channel to selectively output a read current, a plurality of write channels, each to selectively output a different write current, and an oscillator channel to selectively output an oscillator current. Additionally, the hybrid LDD includes programmable LDD controller that receives the plurality of enable signals from the external controller, and based on the enable signals, controls timing of the currents output by at least the write channels. The programmable LDD controller can also control timing of the currents output by the read and oscillator channels, based on the enable signals. Further and alternative embodiments are also provided.

Abstract: The data to be recorded onto a recording medium is directly spread and then recorded onto the recording medium through a needle-shaped member, such as a probe. Upon reproducing the data, the data read from the recording medium is de-spread and reproduced.

Abstract: There are provided a method and apparatus for embedding a second level code into a first level code of an optical disc by data modulation rule variation. The apparatus includes a multi-level, varying rule based modulator (199) for modulating the first level code to obtain a channel bit stream representative of the first level code and having the second level code embedded therein. The multi-level, varying rule based modulator modulates the first level code using modulation rules respectively having different statistical properties of pit-land length distributions that preserve a readability of the first level code and that are distinguishable at readout of the optical disc. The different statistical properties represent binary or multilevel data of the second level code.

Abstract: A record carrier including a data area for storing data in the form of marks, in which the data is encoded by means of a channel code, wherein a parameter of the channel code is controlled so as to introduce a predetermined run length distribution in the marks on the record carrier, thereby introducing first information relating to a watermark, and a non-data area comprising second information relating to a watermark, the first and the second information forming the watermark. This watermark, extending over the data-area and the inner-ring area and/or the outer-ring area, can be used for checking the authenticity of the record carrier and/or the recordings made on this record carrier.

Abstract: Provided herein are hybrid laser diode drivers (LDDs) that drive a laser diode in response to receiving enable signals from a controller. In accordance with specific embodiments, a hybrid LDD includes a read channel to selectively output a read current, one or more write channel each to selectively output a write current, and an oscillator channel to selectively output an oscillator current. Additionally, in specific embodiments the hybrid LDD includes a decoder that receives the enable signals from the controller, and based on the enable signals, controls timing of the currents output by the read, write and oscillator channels.

Abstract: Provided herein are hybrid laser diode drivers (LDDs) that drive a laser diode in response to receiving enable signals from a controller. In accordance with specific embodiments, a hybrid LDD includes a read channel to selectively output a read current, one or more write channel each to selectively output a write current, and an oscillator channel to selectively output an oscillator current. Additionally, in specific embodiments the hybrid LDD includes a state machine that receives the enable signals from the controller, and based on the enable signals, controls timing of the currents output by the read, write and oscillator channels.

Abstract: An optical disk apparatus for suppressing a DSV and performing R-OPC. An encoding/decoding circuit inserts a synchronization information item to a head of a synchronous frame once when data are recorded on an optical disk. First, the encoding/decoding circuit inserts synchronization information as a mark or a space on the basis of a DSV. When the polarity of the first synchronization information item is a mark, the polarity of a next synchronization information item is also set on the basis of the DSV. When the polarity of the first synchronization information is a space, the polarity of the next synchronization information is set to a mark. R-OPC is performed at a timing when the polarity of the synchronization information is a mark.

Abstract: The present invention provides a polycarbonate resin produced by the continuous interfacial process characterized in that after alkaline hydrolysis with sodium hydroxide, the polycarbonate resin contains an amount of 0.01 to 150 ppm of carbamate compounds according to formula (1) said amount measured by high pressure liquid chromatography, wherein R1 and R2 independently of one another denote hydrogen or C1-C12-alkyl, or together denote C4-C12-alkylidene, and R3 and R4 independently of one another denote hydrogen. C1-C12-alkyl or phenyl, or together with the carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, the process comprising phosgene reacting with at least one bisphenol at 8 to 17% molar excess of phosgene relative to the bisphenol.

Abstract: The objects of the present invention are to facilitate the driving of the recording energy source, and to secure sufficient cooling time of the recording medium to promote the high-speed formation of high-precision marks and to provide high-speed and large-capacity information recording apparatuses at a low cost. To achieve the above objects, at the time of information recording, p is chosen as the integer constant for marks natural number k times long of the detection window width by referring to the mark length in the recording data sequence, the recording data sequence is discriminated according to the quotient obtained by and the remainder remaining after dividing k+p by two or more integer constants, and the energy generating means is driven according to different procedures based on the result of discrimination obtained thereby.

Abstract: The present invention enables audio data to be recorded or played back more easily. LPCM samples from an LPCM sample 301-1 of a first channel to an LPCM sample 304-1 of a fourth channel in audio data are combined in order to generate a GOLS 310-1. An even number of GOLS are combined to generate an audio frame. Header information is added to the audio frame to generate an audio PES packet, which is multiplexed with a video PES packet and recorded onto a recording medium. As a result, the number of bits of the audio frame is an integral multiple of 32. This increases an affinity with a recording and playback apparatus.

Abstract: An apparatus and method for look-ahead data detection are provided, the apparatus including a boundary function generator, a boundary decision unit in signal communication with the boundary function generator, a next state generator in signal communication with the boundary decision unit, and a sample value generator in signal communication with the boundary decision unit; and the method including receiving a pickup signal sensed from an optical disc, providing a boundary function value responsive to the pickup signal, comparing the boundary function value with a programmable register value, generating decision outputs responsive to the boundary function value with combinational logic, generating a next state and detected data responsive to the decision outputs, and generating a detected sample value responsive to the decision outputs.

Abstract: A method of recording and/or reproducing data on and/or from an information recording medium including a compatibility information area in which compatibility information, which specifies whether each area on the information recording medium is recordable and/or reproducible, is recorded, the method includes reading the compatibility information, which specifies whether each area on the information recording medium is recordable and/or reproducible; and recording and/or reproducing the data on and/or from the information recording medium with reference to the compatibility information, wherein if other write protection forms of the information recording medium exist, write protection of the information recording medium is determined, based on a result of performing an OR function on the compatibility information and the other write protection forms.

Abstract: A data recording device. A random data generator randomly generates substitute data. A recording data generator receives original data and a recording address from a host, receives the substitute data, compares the recording address with a reference address, and outputs the substitute data according to the comparison result. An encoder generates a first data block according to the substitute data. A modulator modulates the first data block. An optical pickup records the modulated first data block on the optical recording medium according to the recording address.

Abstract: A method for recording a unique ID to a read-only optical disk adopts the 1-7 PP modulation technique and provides in a plurality of predetermined positions postscript areas each having a predetermined postscript pattern. The postscript pattern takes a form of 3T (pit)-2T (land)-3T (pit) and has a length of 8T (largest code length of a modulated bit string). Modulated bit strings before and after the 3T-2T-3T postscript pattern are formed so that the pit-land-pit postscript pattern complies with the rule of the variable-length modulation even when it is replaced as a whole with a pit-only pattern. Further, the land in the middle will not physically change when irradiated with laser light having a reading-level power, but will be melted with a power higher than the reading-level one.

Abstract: A clock mark for extracting a clock when reproducing information from a recording medium and a synchronization mark for detection a bit-slip are recorded so that a part of the synchronization mark is identical to a pattern of the clock mark. A bit-slip detection and a clock detection are performed simultaneously with a single mark by multi-value recording.

Abstract: A recording and reproducing system is broken down into a recording unit for producing a digital audio data signal from MIDI music data words asynchronously produced at irregular intervals and a playback unit for reproducing the MIDI music data codes from the digital audio data signal, wherein synchronous data nibbles are supplemented in the irregular intervals among the MIDI music data words for producing a data stream, and the digital audio data signal is produced from the data stream through a differential phase shift keying and a phase code modulation so as to record the MIDI messages in a digital versatile disk at high dense.

Abstract: An optical storage medium can be provided by which illegal usage of the optical storage medium involving an infringement on the copyright can be prevented effectively without impairment of the functions for reproducing physical format information and optical storage medium manufacturing information. The optical storage medium includes a main information region in which encrypted data information is recorded as a pit row that is capable of being read out by means of light and a control data region. In the control data region, key information for decoding the encryption of the data information, the physical format information and the optical storage medium manufacturing information are recorded by wobbling a groove.

Abstract: A method and apparatus for overwriting data in a probe-based data storage device wherein data is represented by the presence and absence of pits formed in a storage surface by a probe of the device is provided. Input data is first coded such that successive bits of a given value x in the coded input data (b0, b1, b2, . . . ,) are separated by at least d bits of the complementary value {tilde over (x)}, where d is a predetermined number?2. Overwrite data bits (v0, v1, v2, . . . ,) are then generated by encoding the coded input data bits (b0, b1, b2, . . . ,).

Abstract: Polycarbonate resin containing small amounts of carbamate compounds is disclosed. The resin that contains at least one of compounds conforming to wherein R1 and R2 independently of one another denote hydrogen or C1-C12-alkyl, or together denote C4-C12-alkylidene, R3 and R4 independently of one another represent hydrogen, C1-C12-alkyl, or phenyl, or together with the carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, and R5 denotes hydrogen, C1-C12-alkyl, C5-C12-cycloalkyl, phenyl or cumyl, are characterized by their low electrostatic field and therefore suitable for making optical storage media.

Abstract: There is provided a method for recording an unique ID to a read-only optical disk (1) adopting the 1-7 PP modulation technique and having provided in a plurality of predetermined positions postscript areas each having a predetermined postscript pattern formed therein. The postscript pattern takes a form of 3T (pit)-2T (land)-3T (pit) and has a length of 8T (largest code length of a modulated bit string). Modulated bit strings before and after the 3T-2T-3T postscript pattern are formed so that the pit-land-pit postscript pattern complies with the rule of the variable-length modulation even when it is replaced as a whole with a pit-only pattern. Further, the land in the middle of the pit-land-pit postscript pattern is formed from a material which will not physically change when irradiated with laser light having a reading-level one but will be melted when irradiated with laser light having a power higher than the reading-level one.

Abstract: An information storage medium includes a drive zone having a plurality of physical clusters or ECC blocks. When new drive data is recorded in the drive zone, the new drive data is recorded in a physical cluster or ECC block next to the physical cluster or ECC block containing the most recently recorded drive data. In the method of recording drive data, the drive data is recorded in a physical cluster or ECC block of the drive zone. When the drive zone is updated with the new drive data, the new drive data is recorded in the physical cluster or ECC block adjacent to physical cluster or ECC block containing the most recently drive data. The drive data recording method is applicable to a new format of information storage medium.

Abstract: The optical disk recording apparatus includes: a strategy circuit for converting recording data into a pulse train signal for defining an irradiation timing of laser light by using one of first and second conversion rules for forming different marks; a control unit for changing the conversion rule used for the strategy circuit after a timing of forming a contour of an image has passed at the time of forming the image on an optical disk, and when a timing of addition of a synchronization pattern to EFM data has arrived; and a current selecting unit for selecting a current in accordance with the pulse train signal based on the strategy circuit and for supplying it to a semiconductor laser.

Abstract: A system for modulating digital binary data to be recorded on a recording medium comprises the generation of channel bits of the digital binary data to be recorded according to a standard for the recording medium with the exception that a maximum run length larger than that defined in the standard is obtained and/or the merging decision is influenced on basis of a random noise in a predetermined pattern or in at least one predetermined position on said recording medium and/or by recording at least one part comprising at least one predetermined repetitive bit pattern which normally, i.e. according to the standard for the recording medium, encodes into channel bits having a spectral distribution that shows at least one range of frequencies with a characteristic amplitude distribution.

Abstract: An information record apparatus includes a recording device for recording information into a record medium, where pre-information for controlling a recording of the information is recorded in advance, by irradiating the record medium with a laser beam whose power is varied depending on a driving pulse; a first controlling device for modifying the driving pulse into at least a top pulse and a middle pulse; an optimum ratio detecting device for detecting an optimum ratio that is a pulse ratio at which a first reproduction quality that is a reproduction quality of the pre-information meets a first reference, on the basis of a first correlation information to indicate a correlation between the first reproduction quality and a pulse ratio of at least the top pulse to the middle pulse; and a second controlling device for modifying the driving pulse in accordance with a pulse ratio corresponding to the optimum ratio.

Abstract: An apparatus and method to modulate address data of a disc type recording medium, include generating the address data, performing error correction coding of the address data and outputting coded address data, receiving the coded address data in a unit of at least two bits, generating a first modulated signal of the coded address data using a first modulation technique, generating a second modulated signal of the coded address data using a second modulating signal, and generating a unit wobble signal by synthesizing the first and second modulated signals.

Abstract: A data recording method according to the present invention is a method for recording data as edge position information, including marks and spaces of multiple different lengths, on a storage medium by irradiating the storage medium with a pulsed energy beam. The method includes the steps of: (A) generating a write code sequence based on the data to be recorded; (B) determining a write pulse waveform, defining the power modulation of the energy beam, according to the code lengths of respective codes included in the write code sequence; and (C) modulating the power of the energy beam based on the write pulse waveform.

Abstract: Described herewith is an optical disk manufacturing apparatus for reading recorded digital data from an optical disk, comprising an encryption unit (22, 23) for encrypting entered digital data according to a plurality of key information; an optical disk substrate manufacturing unit 2 for manufacturing an optical disk substrate 4 on which the encrypted digital data and key information are recorded in the form of physical form changes; a reflection film forming unit 41 for forming a reflection film on the optical disk substrate 4; and a key information recording unit 7 for recording key information on the optical disk substrate on which the reflection film is formed. The reflection factor of the optical disk is changed locally, thereby giving a jitter to the position information of each pit edge, and desired data is recorded additionally according to this jitter. Pits, etc.

Abstract: A ROM disk having a block data format provided with linking areas as with a rewritable disk. Main data recorded in a main data area and linking data recorded in a linking area in each block are scrambled by identical scrambling data. The scrambling data is generated by a random sequence using address information of the block as an initial value.

Abstract: An optical disk apparatus for forming an image on an optical disk according to dot data which defines density of dots of the image, the optical disk apparatus includes: a framing unit which makes a frame data by grouping a plurality of unit data, wherein when the dot data, the dot data are treated as the unit data; a pit forming unit which sequentially forms pits defined by a bit train signal of the frame data; a discrimination unit which determines whether the section in the frame data corresponding to the dot data is a predetermined value; and a gate unit which, in case the discrimination result by the discrimination unit is affirmative, supplies the bit train signal to the pit forming unit and, in case the discrimination result by the discrimination unit is negative, interrupts supply of the bit train signal to the pit forming unit.

Abstract: A mark representing information of a multivalued level is recorded in each of cells arranged in a recording medium. Upon reproducing the multivalued level from a reproduction signal of the recording medium, the multivalued level of a present cell is judged by referring to a judged multivalued level of a preceding cell preceding the present cell or an ensuing cell ensuing the present cell, or by referring to the judged multivalued levels of both the preceding cell and the ensuing cell.