Abstract: Underwater voice communication devices and associated methods are described. According to one aspect, an underwater voice communication device includes a voice chamber comprising a face seal which is configured to form at least a substantially watertight seal with respect to a mouth of a first user, wherein the voice chamber comprises an internal volume, an earpiece comprising an ear seal which is configured to form at least a substantially watertight seal with respect to an ear of a second user, wherein the earpiece comprises an internal volume which is in fluid communication with the internal volume of the voice chamber, and wherein the internal volumes of the voice chamber and earpiece communicate voice sound waves from the mouth of the first user to the ear of the second user.

Abstract: An aspect of some embodiments of the present invention relates to a system for processing audiovisual data. The system is configured to mediate between a user and an audio post-processing system, to enable the user to easily assign sounds to corresponding objects in a scene and for selecting suitable sounds effects to be applied to desired sounds by the post-processing system. Optionally, the sounds effects are selected according to distances between the objects and the camera and/or distances between objects in the scene with other objects which may or may not be in the scene.

Abstract: Methods, computer program products, and systems are presented. The methods include, for instance: determining that one or more word of a feature vector more supports than negates a language model corresponding to the domain based on a sensitivity of respective word. Words having acceptable sensitivities are added to the language model, and the language model is enhanced by use of machine learning in order to accurately and comprehensively model the language specific for the domain.

Abstract: A keyword spotting system includes a decoder having a storage device and a decoding circuit. The storage device is used to store a log-likelihood table and a plurality of dynamic programming (DP) tables generated for recognition of a designated keyword. The decoding circuit is used to refer to features in one frame of an acoustic data input to calculate the log-likelihood table and refer to at least the log-likelihood table to adjust each of the DP tables when recognition of the designated keyword is not accepted yet, where the DP tables are reset by the decoding circuit at different frames of the acoustic data input, respectively.

Abstract: In accordance with an aspect, there is provided a system and method for electronic communications that involves machine learning and natural language processing for contact relationship discovery, ranking and retrieval. In accordance with an aspect, there is provided a system and device that discovers contacts related to user search terms, quantitatively measures and ranks the strength between contact relationships according to a score calculated by natural language processing and machine learning. The system generates visual effects to present recommendations to the user with multiple alternate route options to establish relationships between contacts.

Abstract: Systems, methods, and devices for recognizing a user are disclosed. A speech-controlled device captures a spoken utterance, and sends audio data corresponding thereto to a server. The server determines content sources storing or having access to content responsive to the spoken utterance. The server also determines multiple users associated with a profile of the speech-controlled device. Using the audio data, the server may determine user recognition data with respect to each user indicated in the speech-controlled device's profile. The server may also receive user recognition confidence threshold data from each of the content sources. The server may determine user recognition data associated that satisfies (i.e., meets or exceeds) a most stringent (i.e., highest) of the user recognition confidence threshold data. Thereafter, the server may send data indicating a user associated with the user recognition data to all of the content sources.

Abstract: A system of multi-modal transmission of packetized data in a voice activated data packet based computer network environment is provided. A natural language processor component can parse an input audio signal to identify a request and a trigger keyword. Based on the input audio signal, a direct action application programming interface can generate a first action data structure, and a content selector component can select a content item. An interface management component can identify first and second candidate interfaces, and respective resource utilization values. The interface management component can select, based on the resource utilization values, the first candidate interface to present the content item. The interface management component can provide the first action data structure to the client computing device for rendering as audio output, and can transmit the content item converted for a first modality to deliver the content item for rendering from the selected interface.

Abstract: A system, for implementation at a vehicle of transportation, having multiple arrangements of occupant-zone-specific acoustic equipment in the vehicle. Each arrangement is positioned at a respective occupant-specific acoustic zone of the vehicle. Each arrangement is configured to communicate with a hardware-based processing unit that, when executing code of a hardware-based storage device in operation of the system, interacts, via the arrangement, primarily only with a vehicle occupant occupying a corresponding occupant-specific acoustic zone. In some implementations, along with or instead of the acoustic equipment, the system includes multiple arrangements of occupant-zone-specific acoustic equipment in the vehicle. In various embodiments, based on identification of occupants at respective vehicle zones in operation of the vehicle, operations are performed, such as provision of media, vehicle-occupant conversation, and customized HVAC delivery.

Abstract: Techniques disclosed herein include systems and methods for open-domain voice-enabled searching that is speaker sensitive. Techniques include using speech information, speaker information, and information associated with a spoken query to enhance open voice search results. This includes integrating a textual index with a voice index to support the entire search cycle. Given a voice query, the system can execute two matching processes simultaneously. This can include a text matching process based on the output of speech recognition, as well as a voice matching process based on characteristics of a caller or user voicing a query. Characteristics of the caller can include output of voice feature extraction and metadata about the call. The system clusters callers according to these characteristics. The system can use specific voice and text clusters to modify speech recognition results, as well as modifying search results.

Abstract: Techniques for combining the results of multiple recognizers in a distributed speech recognition architecture. Speech data input to a client device is encoded and processed both locally and remotely by different recognizers configured to be proficient at different speech recognition tasks. The client/server architecture is configurable to enable network providers to specify a policy directed to a trade-off between reducing recognition latency perceived by a user and usage of network resources. The results of the local and remote speech recognition engines are combined based, at least in part, on logic stored by one or more components of the client/server architecture.

Abstract: Aspects define a capture signal as audio inputs by a user of word content. An input of the capture signal word content is recognized in response to an audio input of the user reciting the capture signal word content into a microphone in communication with the recording device during a recording of a speech presentation by the recording device. A recording portion start time is identified that is prior to a time of the input of the capture signal during the current recording of the audio speech presentation in response to recognizing the input of the capture signal word content from the user. The recording device is driven to capture a portion of the recorded audio speech presentation over a period of time spanning from the recording portion start time to the time of the input of the capture signal word content.

Abstract: A circuit to compensate for a lost audio frame, comprising: an identifier configured to identify a reference audio segment with a first length followed by the lost audio frame with a second length; a searcher coupled to the identifier and configured to search for a first audio segment similar to the reference audio segment in a cached audio segment followed by the reference audio segment by utilizing a cross-correlation search; the identifier further configured to identify a second audio segment subsequent to the first audio segment as a pre-compensated audio frame; an adjustor coupled to the identifier and configured to adjust an amplitude of the second audio segment based on a scale factor; and an output coupled to the adjustor to output the adjusted second audio segment as a compensated audio frame.

Abstract: An apparatus for processing an input audio signal relies on a cascade of filterbanks, the cascade having a synthesis filterbank for synthesizing an audio intermediate signal from the input audio signal, the input audio signal being represented by a plurality of first subband signals generated by an analysis filterbank, wherein a number of filterbank channels of the synthesis filterbank is smaller than a number of channels of the analysis filterbank. The apparatus furthermore has a further analysis filterbank for generating a plurality of second subband signals from the audio intermediate signal, wherein the further analysis filterbank has a number of channels being different from the number of channels of the synthesis filterbank, so that a sampling rate of a subband signal of the plurality of second subband signals is different from a sampling rate of a first subband signal of the plurality of first subband signals.

Abstract: Provided is a method and apparatus for encoding/decoding an audio signal. Sections which are not used to output noise components near important spectral components and sub-bands which are not used to output noise components, are determined to be encoded or decoded, so that the efficiency of encoding and decoding an audio signal increases, and sound quality can be improved using less bits.

Abstract: Embodiments of the present application proposes a frequency envelope vector quantization method and apparatus, where the method includes: dividing N frequency envelopes in one frame into N1 vectors; quantizing a first vector in the N1 vectors by using a first codebook, to obtain a code word corresponding to the quantized first vector, where the first codebook is divided into 2B1 portions; determining, according to the code word corresponding to the quantized first vector; determining a second codebook according to the codebook of the ith portion; and quantizing a second vector in the N1 vectors based on the second codebook. In the embodiments of the present application, vector quantization can be performed on frequency envelope vectors by using a codebook with a smaller quantity of bits. Therefore, complexity of vector quantization can be reduced, and an effect of vector quantization can also be ensured.

Abstract: An apparatus includes microphone receivers configured to receive microphone signals from a plurality of microphones. A comparator configured to determine a speech similarity indication indicative of a similarity between the microphone signal and non-reverberant speech for each microphone signal. The determination is in response to a comparison of a property derived from the microphone signal to a reference property for non-reverberant speech. In some embodiments, the comparator is configured to determine the similarity indication by comparing to reference properties for speech samples of a set of non-reverberant speech samples. A generator is configured to generate a speech signal by combining the microphone signals in response to the similarity indications. The apparatus may be distributed over a plurality of devices each containing a microphone, and the approach may determine the most suited microphone for generating the speech signal.

Abstract: A method for speech enhancement in speech communication devices and more specifically in hearing aids for suppressing stationary and non-stationary background noise in the input speech signal signals is disclosed. The method uses spectral subtraction wherein the noise spectrum is updated using quantile-based estimation without voice activity detection and the quantile values are approximated by dynamic quantile tracking without involving large storage and sorting of past spectral samples. The technique permits use of a different quantile at each frequency bin for noise estimation without introducing processing overheads. The preferred embodiment uses analysis-modification-synthesis based on Fast Fourier transform (FFT) and it can be integrated with other FFT-based signal processing techniques used in the hearing aids and speech communication devices.

Abstract: An automatic speech recognition (“ASR”) system produces, for particular users, customized speech recognition results by using data regarding prior interactions of the users with the system. A portion of the ASR system (e.g., a neural-network-based language model) can be trained to produce an encoded representation of a user's interactions with the system based on, e.g., transcriptions of prior utterances made by the user. This user-specific encoded representation of interaction history is then used by the language model to customize ASR processing for the user.

Abstract: A system, method, and apparatus for detecting drones are disclosed. An example method includes receiving a digital sound sample and partitioning the digital sound sample into segments. The method also includes applying a frequency and power spectral density transformation to each of the segments to produce respective sample vectors. For each of the sample vectors, the example method determines a combination of drone sound signatures and background sound signatures that most closely match the sample vector. The method further includes determining, for the sample vectors, if the drone sound signatures in relation to the background sound signatures that are included within the respective combinations are indicative of a drone. Conditioned on determining that the drone sound signatures are indicative of a drone, an alert message indicative of the drone is transmitted.

Abstract: Systems and methods are disclosed for displaying electronic multimedia content to a user. One computer-implemented method for manipulating electronic multimedia content includes generating, using a processor, a speech model and at least one speaker model of an individual speaker. The method further includes receiving electronic media content over a network; extracting an audio track from the electronic media content; and detecting speech segments within the electronic media content based on the speech model. The method further includes detecting a speaker segment within the electronic media content and calculating a probability of the detected speaker segment involving the individual speaker based on the at least one speaker model.

Abstract: A vibration damper for a disk drive suspension includes a viscoelastic damping layer, a substantially stiffer polymer constraining layer, and a metal layer interposed between the viscoelastic layer and the polymer constraining layer, such as a thin layer of aluminum vapor deposited onto the polymer constraining layer. The metal layer hides irregularities in the viscoelastic layer as that viscoelastic layer is adhered to the suspension without introducing potentially contaminating mineral particles into the polymer constraining layer.

Abstract: The presently disclosed technology teaches integrating disc drive electronics into a transducer head. Decreased electrical transit times and data processing times can be achieved by placing the electronics on or within the transducer head because electrical connections may be made physically shorter than in conventional systems. The electronics may include one or more of a control system circuit, a write driver, and/or a data buffer. The control system circuit generates a modified clock signal that has a fixed relation to phase and frequency of a bit-detected reference signal that corresponds to positions of patterned bits on the disc. The write driver writes outgoing data bits received from an external connection to off-head electronics directly to the writer synchronized with the modified clock signal. The data buffer stores and converts digital data bits sent from the off-head electronics to an analog signal that is synchronized with the modified clock signal.

Abstract: An apparatus comprises a slider configured for heat assisted magnetic recording and comprising a substrate. At least one component of the slider generates heat when energized. At least one thermal via extends through a portion of the slider from a location proximate the component to the substrate. The thermal via is configured to conduct heat away from the component and to the substrate.

Abstract: A PMR (perpendicular magnetic recording) head includes a tapered write pole that is fully surrounded by wrapped-around magnetic shields, including laterally disposed side shields, a trailing shield and a leading shield. A layer of high magnetic saturation material (high Bs) is formed on the leading edge of the trailing shield and extends rearward, away from the ABS plane to define a cross-sectional write gap shape that is not conformal with the shape of the tapered write pole. The cross-sectional shape of this shield layer enables it to absorb flux from the write pole so that the flux for writing is enhanced and concentrated at the area of the recording medium being written upon and does not extend to adjacent tracks or to downtrack positions at which such flux is not desired.

Abstract: A magnetic recording head comprises: a main magnetic pole for generating a recording magnetic field applied to a magnetic recording medium from an end surface that is one part of an air bearing surface facing the magnetic recording medium; a trailing shield that is placed by interposing a write gap at a trailing side of the main magnetic pole; and a spin torque oscillator provided in the write gap; wherein, when viewed from the air bearing surface side, the length in the down-track direction between the trailing shield and the cross-track direction end portion of a first end face positioned at the main magnetic pole side of the spin torque oscillator is longer than the length in the down-track direction between the trailing shield and the main magnetic pole at a center position in the cross-track direction of the spin torque oscillator.

Abstract: An apparatus according to one embodiment includes a head having at least two modules, each having an array of transducers. Axes of the arrays are about parallel and are spaced from one another in an intended direction of tape travel thereacross. The array of a first of the modules is offset from the array of a second of the modules in a first direction parallel to the axis of the array of the second module such that the transducers of the first module and the transducers of the second module are positioned to fill a contiguous data band with written tracks in multiple passes. All of the transducers of the first module are positioned on a first side of an imaginary line oriented in the intended direction of tape travel, and all of the transducers of the second module are positioned on a second side of the imaginary line.

Abstract: An edge surface of a magnetic-disk glass substrate containing an alkali metal component as a glass composition is a mirror surface, and in a bearing ratio curve of roughness cross-sectional areas obtained by measuring a surface roughness of the edge surface obtained by etching the edge surface by 2.5 ?m, a roughness percentage when a bearing ratio of a roughness cross-sectional area is 50% is 40% or more.

Abstract: A data recording apparatus including: a data reading device configured to read data from a first recording medium and configured to store data and first management data for managing the data by file; a data recording device configured to record data on a second recording medium; a management data producing device configured to produce second management data for managing data recorded on the second recording medium based on the first management data of the first recording medium on which the data recorded on the second recording medium has been recorded; a data determining device configured to determine data unrecorded on the second recording medium by comparing the first management data read by the data reading device from the first recording medium with the second management data recorded on the second recording medium; a control device configured to read the data determined by the data determining device from the first recording medium and cause the recording device to record the read data onto the second r

Abstract: Embodiments disclosed herein provide systems, methods, and computer readable media to handle unsuccessful movements of removable storage media in an automated removable media system. In a particular embodiment, a method provides receiving one or more user provided parameters that indicate one or more types of unsuccessful media move operations that should be reported as successful. The method further provides receiving a first request to move a first item of removable storage media from a first position in the automated removable media system to a second position in the automated removable media system and initiating a first move operation of the first item from the first position to the second position by at least one changer device. The method then provides determining that the first move operation resulted in one of the one or more types of unsuccessful media move operations and indicating that the first move operation was successful in response to the first request.

Abstract: A system and method are provided for enhancing an audio recording which comprises a recording of a sound signal obtained from the play-out of an audio signal via a speaker. The audio signal, and thereby the sound signal, may represent certain audio content, e.g., a radio station or TV audio. To perform the enhancing, the recording of the sound signal is suppressed using the audio signal, thereby obtaining an intermediate audio recording. An original version of the audio content is then added to the intermediate audio recording to obtain an enhanced audio recording. This original version is generally of higher quality as it generally does not represent a background audio component but rather was purposefully recorded or generated.

Abstract: In general, techniques are described for monitoring health of a head in a magnetic data storage drive. A health controller may be configured to receive multi-variate sensor signals indicative of a respective reference value at least one head parameter, wherein the respective reference value is based in part on at least one initial measurement of parameters of the head obtained at a first time, determine a respective predicted current value based at least in part on a respective fixed-drift model and the multi-variate sensor signals, determine a respective actual current value that is based at least in part on at least one current measurement of the head obtained at a second time later than the first time, determine a health status for the head, and store the health status in memory.

Abstract: Methods and systems are provided herein for modifying playlists of media assets. In some aspects, these methods and systems are provided by way of receiving a user input that causes a media asset in a playlist to cease from being played back and to be removed from the playlist. User interactions associated with the playlist may subsequently be monitored, where, in response to detecting a user interaction while monitoring, a number of user interactions that have been received subsequent to the user input may be determined. The number of user interactions may be compared to a threshold number, and, when the number of user interactions corresponds to the threshold number, the media asset may be inserted into the playlist.

Abstract: A video replay system which allows for the playback of video files from a buffer in random access memory and from disk to minimize the delay between capturing and replaying a desired video portion. In one embodiment, a portion of RAM is allocated to provide a buffer for holding video files in memory before the files are written to a hard drive or other non-volatile storage. An index of key frames is also stored in the buffer. The computer system executes software that is responsive to an operator's commands to read the video files and index and playback desired video portions in a variety of modes and speeds, including slow motion, reverse, fast-forward, and slow or fast reverse.

Abstract: Digital content, such as video, audio, multimedia, and similar files may be segmented at a determined frame resolution rate and analyzed to determine a fingerprint for each content segment. An identifier that uniquely identifies each content segment may be determined based on the fingerprint of the respective content segment. The identifier may be associated with data relating to the content segment and with one or more identifiers that uniquely identify other content segments of the content. The content segment identifiers may be used to construct a content segment sequencing representation that represents the playback of the content segments in playback order.

Abstract: In a method of producing a composite animation live captured image sequence by capturing a live action sequence of action scenes with an image capture device, which include a stand-in for an animated feature or character, generating concurrently with the live action sequence configuration data for the stand-in, positioning data associated with the stand-in derived through machine vision techniques applied to the live action sequence image frames; producing from the configuration data and the positioning data a computer-generated animated sequence for combining with the captured image sequence to produce composite image sequence comprising the animated feature in place of the stand-in, both the configuration data and frame-by-frame virtual camera data corresponding to the live action image captured frames can be synchronously incorporated enabling efficient and effective production of composite animation live action digital video or film or broadcast.

Abstract: Provided is a system for efficiently creating snippets or clips from media assets without re-encoding the entire portion of already encoded media content falling within the snippet boundaries. The system partitions and encodes the original media asset as set of slices with each slice encoding a different temporal chunk of the media asset. The system identifies a first slice that encodes a duration of the media asset spanning the snippet start time, and a second slice that encodes a duration of the media asset spanning the snippet end time. The system produces a snippet start slice from decoding, clipping, and re-encoding the first slice and a snippet end slice from decoding, clipping, and re-encoding the second slice. The system generates the snippet from the snippet start slice, an unmodified subset of the set of slices between the first slice and the second slice, and the snippet end slice.

Abstract: A CPU extracts still images from image files recorded at predetermined time intervals among still images and moving images arbitrarily recorded in a predetermined period such as one day, and generates a time-lapse moving image by taking these extracted images as frames. That is, in addition to still images, even when a moving image file is recorded at timing corresponding to a predetermined time interval, a frame at the timing corresponding to the predetermined time interval in the moving image file is extracted, and adopted as a frame of a time-lapse moving image to be generated.

Abstract: An embodiment of the present invention provides a summary image browsing system and method. A summary image browsing method of the present invention may comprise the steps of: tracking motion trajectory of an object from an input video; extracting the object from the input video and then generating a series of object segments; and synthesizing the series of object segments with a background image along the motion trajectory of the object and generating a summary image having a thickness according to an occurrence time interval for each object extracted from the input video.

Abstract: A digital video builder system with methodology for designer-controlled user interaction is described. In one embodiment, for example, a method comprises receiving, from interactive controls on a graphical user interface, configuration of a storyboard block of a storyboard of a target digital video to be created. The storyboard block represents a scene of the target digital video, comprises a media element slot and a scene parameter for configuring the media element slot, and corresponds to a scene specification having a plurality of scene variants for rendering the scene of the target digital video. The received configuration comprises a setting for the scene parameter. Based on the scene parameter setting, the method further includes automatically selecting one of the plurality of scene variants for use in rendering as part of the scene of the target digital video.

Abstract: A multimedia file and methods of generating, distributing and using the multimedia file are described. Multimedia files in accordance with embodiments of the present invention can contain multiple video tracks, multiple audio tracks, multiple subtitle tracks, a complete index that can be used to locate each data chunk in each of these tracks and an abridged index that can enable the location of a subset of the data chunks in each track, data that can be used to generate a menu interface to access the contents of the file and ‘meta data’ concerning the contents of the file. Multimedia files in accordance with several embodiments of the present invention also include references to video tracks, audio tracks, subtitle tracks and ‘meta data’ external to the file.

Abstract: According to one embodiment, a semiconductor memory device includes: a first insulating layer; a global bit line and a reference bit line provided on the first insulating layer; a second insulating layer provided on the global bit line and the reference bit line; a select gate line provided on the second insulating layer; a first transistor provided on the global bit line; a local bit line coupled to the first transistor; first and second memory cells; and a sense amplifier. The global bit line and the reference bit line three-dimensionally intersect the select gate line via the second insulating layer.

Abstract: An apparatus including a Correlated Electron Switch (CES) element and a programing circuit is provided. The programing circuit provides a programing signal to the CES element to program the CES element to an impedance state of multiple impedance states when a number of times the CES element has been programed is less than a threshold.

Abstract: A system and method is disclosed for managing data in a non-volatile memory. The system may include a non-volatile memory having multiple non-volatile memory sub-drives, including a staging sub-drive to receive all data from a host and a plurality of other sub-drives each associated with a respective data temperature range. A controller of the memory system is configured to route all incoming host data only to the staging sub-drive and during garbage collection each individual piece of valid data from a selected source block in a selected source sub-drive is routed to a respective one of the sub-drives. The method may include only routing host data to the staging sub-drive and only relocating valid data to sub-drives other than the staging sub-drive based on a determined temperature of valid data and a unique temperature range associated with sub-drives other than the staging sub-drive in the non-volatile memory system.

Abstract: This disclosure provides a method and apparatus for detecting a transition of a memory cell current from a first state to a second state. An example apparatus includes a memory cell, a supplemental current source, a comparator, a reference voltage and a reference current source in a configuration that allows for real time detection of the transition of a memory cell. Detection of a memory cell current transition is captured when the output of the comparator transitions from one state to a second state in response to a sensing voltage exceeding the reference voltage.

Abstract: A sense amplifier (SA) comprises a semiconductor substrate having an oxide definition (OD) region, a pair of SA sensing devices, a SA enabling device, and a sense amplifier enabling signal (SAE) line for carrying an SAE signal. The pair of SA sensing devices have the same poly gate length Lg as the SA enabling device, and they all share the same OD region. When enabled, the SAE signal turns on the SA enabling device to discharge one of the pair of SA sensing devices for data read from the sense amplifier.

Abstract: An example apparatus comprises an array of memory cells coupled to sensing circuitry. The apparatus can include a control component configured to cause computing of a data value equal to a logical OR between the digit of a mask and a data value stored in a memory cell located in a row at a column of the array corresponding to a digit of a vector stored in the array. The control component can cause storing of the data value equal to the logical OR in the memory cell located in the row at the column of the array corresponding to the digit of the vector.

Abstract: A semiconductor device that is novel, is capable of high-speed operation, consumes low power, or occupies a small area is provided. The semiconductor device includes a memory portion, a control circuit, and a plurality of wirings. The memory portion includes a plurality of memory circuits. The memory circuit includes a memory cell. The memory cell is electrically connected to a wiring. A first signal that indicates the amount of data that are written to or read from the memory portion is supplied to the control circuit. The control circuit has the function of controlling the number of the wirings to which a second signal for selecting the memory cell is simultaneously supplied on the basis of the first signal.

Abstract: Examples of the present disclosure provide apparatuses and methods for determining a length of a longest element in a memory. An example method comprises determining, using a controller to control sensing circuitry, a length of a longest element of a plurality of variable length elements of a vector stored in a memory array.

Abstract: A data processing system may include a memory/storage circuit and a host. The memory/storage circuit may include a first memory module and a second memory module. Each of the first and second memory modules may include a controller and a memory device. The host may have access to the memory device of the first memory module and the memory device of the second memory module. Each of the controllers included in the first and second memory modules may be configured to selectively perform any one of a memory operation and a storage operation according to a request of the host.

Abstract: A memory apparatus may include a bit line sense-amplifier coupled to first and second bit lines; a first precharge unit suitable for coupling the first and second bit lines in response to a bit line equalization signal; a sense-amplifier power control unit suitable for providing a plurality of powers to the bit line sense-amplifier in response to a power control signal; and a second precharge unit suitable for individually changing each voltage level of the first and second bit lines based on a precharge control signal.