The invention relates to a saw-tooth clothing for rollers of a carding machine or a carder. The saw-tooth clothing has a multiplicity of successively arranged teeth, wherein each tooth has a tooth front and a tooth back and a tooth tip. The tooth backs of the teeth have in each case a certain distance from the tooth front of the in each case following tooth and form a tooth space which extends from a tooth root to the tooth tips. Between the tooth tips and the tooth root, the teeth have in each case on their tooth back and on their tooth front at least one embossment which reduces the distance between the tooth back of the teeth and the tooth front of the in each case following tooth.

In order to produce air-laid non-woven fabrics with an adjustable strength ratio of the production direction and 90° to the production direction, two non-woven laying machines are set at an angle to the production direction.

In a device on a spinning room preparation machine, for example a fiber flock feeder, carding machine, cleaner or the like, for supplying and/or discharging fiber material, a tray-like guide element having a guide surface co-operates with at least one conveyor roll located opposite, the fiber material being guided towards and along the guide surface. In order to provide a simple way of supplying and/or discharging fiber material without undesirable adhesion of fibers, the guide element located opposite the at least one conveyor roll is arranged to be set in vibration by at least one actuator.

A device attaches a flexible clothing in the form of a clothing strip to a card flat bar of a revolving card flat. The card flat bar has a card flat foot with a clothing take-up surface and a web lying above the card flat foot. At least two clips are provided on the clothing strip. The device includes means to accommodate and hold the card flat bar and the clothing strip. The device furthermore includes press rams, which are guided in a moveable manner transversely to the longitudinal direction of the card flat bar and from both sides parallel to the clothing take-up surface of the card flat bar. By means of the movement of the press rams, an integral formation of the clips on the card flat foot is caused. The press rams have a drive with compression hoses.

The front top roller (20) includes a fiber contacting portion (30) and a reduced-diameter portion (31). The fiber contacting portion (30) has a substantially uniform outer diameter. The reduced-diameter portion (31) is provided at both ends of the fiber contacting portion (30) in an axial direction, and is formed with an outer diameter smaller than an outer diameter of the fiber contacting portion (30). The fiber contacting portion (30) has a width (W1) in an axial direction of 18 mm and the outer diameter (D1) of 30 mm. An outer diameter (D2) of the reduced-diameter portion (31) is 25 mm.

A detaching roller apparatus in a combing machine includes a detaching roller and a plurality of electric motors. The detaching roller has a first end and a second end. The electric motors are connected to the detaching roller at positions adjacent to at least one of the first and second ends of the detaching roller for driving the detaching roller reversibly. The electric motors are synchronized.

A fiber laying machine includes a laying head with a roller able to pivot about an axis of rotation and to apply a plurality of preimpregnated fibers to an application surface by rolling over the application surface. The fibers are distributed along a lower generatrix of the roller and in contact with an exterior surface of the roller over an angle of wrap. The roller includes a cylindrical body, pivoting rings around the body, and means for immobilizing the pivoting rings with respect to the body in a direction parallel to the axis of rotation. The pivoting rings are able to pivot independently of one another.

A working assembly (1) includes a rotatable hollow drum or cylinder (2) having a cylindrical wall (3) with ends having transverse header walls (4) with openings (16, 17), and with a longitudinal shaft (5). The external lateral surface of the cylindrical wall (3) has a clothing device intended to interact with the fibers being carded. First and second support uprights (6, 7) are fixed in operation, and adapted to support the ends of the shaft (5) of the drum or cylinder (2) for rotation about a preferably horizontal axis. The support uprights (6, 7) and the drum or cylinder (2) are configured and coupled with each other such as to define at least one fluid path for a flow of a refrigerating fluid, which extends through the openings (16, 17) and inside the drum or cylinder (2) and is adapted to cause cooling of the lateral cylindrical wall (3) thereof.

A wireless access control system may include a remote access wireless communications device and a lock assembly to be mounted on a door. The lock assembly may include a lock, a door position sensor, interior and exterior directional antennas, lock wireless communications circuitry, a touch sensor, and a lock controller. The lock controller may be configured to unlock the lock based upon the touch sensor, determine when the door is closed after being opened based upon the door position sensor, determine whether the remote access wireless device is in an interior or an exterior based upon the directional antennas, switch the lock to the locked position when the door is closed and when the remote access wireless device is in the interior, and not switch the lock to the locked position when the door is closed and when the remote access wireless device is in the exterior.

A wireless access control system may include a remote access wireless communications device and a lock assembly to be mounted on a door. The lock assembly may include a lock, a door position sensor, interior and exterior directional antennas, lock wireless communications circuitry, and a lock controller. The lock controller determine whether the lock is manually unlocked, determine when the door is closed after being opened based upon the door position sensor, and determine whether the remote access wireless device is in an interior or an exterior based upon the directional antennas. The lock controller may also switch the lock to the locked position when the door is closed and when the remote access wireless device is in the exterior, and not switch the lock to the locked position when the door is closed and when the remote access wireless device is in the interior.

A monitoring and alert system for retro-fitting to latching mechanisms. A master control unit is located proximate to an operator of the system. It includes a user interface having: an input enabling an operator to arm the system and then allow it to operate with minimal interaction of the operator. It also includes an output alerting the operator as to the status of the system in relation to a plurality of prescribed conditions. One or more slave units having sensing units detecting a latched and unlatched state are attached to a discrete latching mechanism for detecting the latching status thereof. Each slave unit comprises sensing means to detect whether the latching mechanism is in a latched state or an unlatched state.

A door for attachment on the front of a machining tank of an electric discharge machine includes a door frame and first and second lifting doors that move up and down with respect to the door frame. When the first lifting door is lifted, pulleys attached on the first lifting door also move up, causing a belt wound around the pulleys and fixed to the door frame via a first belt-attaching member to rotate. As a result, the second lifting door, fixed to the belt via a second belt-attaching member, moves up with respect to the first lifting door.

A database system provides a non-volatile cache memory layer for caching pages for a set of database from the database system. The non-volatile cache memory layer may include a non-volatile cache for caching pages for a database from the set of database on the database system. The non-volatile cache may be configured through invoking a configuring stored procedure persistent on the database system. A request is received at the non-volatile cache memory layer for performing an operation on a page from the database on the database system. Based on the received request and an identification of the page, a caching operation is performed on the non-volatile cache memory layer. The caching operation is associated with the request. Data associated with the requested operation on the page is stored and organized on the NV cache memory layer.

Embodiments include a system, method, and computer program product for foreign organization name matching. Aspects include receiving a first entity name from a first database configured in a first language and receiving a second database, wherein the second database includes a plurality of entity names in a second language, wherein the first and second languages are different. Aspects also include performing an Internet search based on the first entity name, wherein a language setting of the Internet search is configured to the second language and identifying a list of candidate names based on a set of results from the Internet search. Another aspect includes filtering the list to obtain a resulting candidate name and determining whether the resulting candidate name matches one of the entity names in the second database. Aspects include associating the first entity name and a matching entity name in the second database based on the determination.

There is provided a method for fingerprinting and matching of content of a multi-media file. The method comprises extracting (S1) fingerprints from at least a portion of the multi-media file in the form of content features detected in at least two different modalities, each content feature detected in a respective modality, and building (S2) a multi-vector fingerprint pattern representing the multi-media file by representing the content features in at least one feature vector per modality. The method also comprises comparing (S3) the multi-vector fingerprint pattern to fingerprint patterns corresponding to known multi-media content, in a database based on a multi-modality matching analysis to identify whether the multi-vector fingerprint pattern has a level of similarity to any of the fingerprint patterns in the database that exceeds a threshold.

Disclosed are a Chinese website classification method and system based on characteristic analysis of a website homepage. The method specifically comprises the following steps: S1, crawling website content; S2, labeling a website type; S3, extracting website information; S4, calculating a weight and representing the weight in the form of a characteristic vector; and S5, classifying the website by comparing the characteristic vector. By utilizing the above Chinese website classification method and system, the noise interference can be alleviated to the greatest extent by only extracting a title and meta-information of the website; by means of pre-processing and characteristic vector expression, the characteristics of the website are accurately expressed with the vector, so that the accuracy of classification is increased; and since only the title and meta-information of the website need to be processed, the quantity of data to be processed is small, and the processing speed is high.

The present disclosure relates to a method for searching in a database containing at least one set of objects each linked to at least one descriptor, the search being done by a search engine from at least one request by a user in order to return at least one result object. The request includes at least one search parameter having a series of at least one search element obtained by freely adding elements to the series by the user, the addition step being able to be repeated multiple times until a search instruction is given.

A windrower with a harvesting header with a crop cutting assembly for severing crop from the ground windrower has a header pitch sensor for measuring a fore/aft pitch angle and a hydraulic system. The hydraulic system moves the header between an operating height and a raised position, and also controls a fore/aft pitch angle. An electronics control module provides an output to activate solenoid valves in the hydraulic system to move the header between the operating height and the raised position and to select a desired pitch angle. When the header moves from the operating height to the raised position, the electronics control module operates the header hydraulic system to move the header to the zero-tilt condition, and upon lowering the header back the operating height, the electronics control module automatically returns the header to the selected pitch angle it was in at the start of the cycle.

An electromotive drive device of an electric motor-driven mini-excavator, which is capable of lengthening its operating time, includes an electric power storage device, a motor-generator, a hydraulic pump, a plurality of directional control valves which respectively control the flow of pressurized fluid, and a plurality of operating devices which respectively operate the plurality of directional control valves. The electromotive drive device is provided with a bidirectional converter which decelerates the motor-generator to an idle revolution speed when X seconds have elapsed in a state in which the plurality of directional control valves are all not operated. The bidirectional converter performs regenerative control to convert an inertial force of a rotor of the motor-generator to power and charge the electric power storage device when it decelerates the motor-generator from a standard revolution speed to the idle revolution speed.

An agricultural work vehicle includes a vehicle body having longitudinally extending sides. An enclosed engine compartment is configured within the vehicle body. An air inlet is defined in side of the vehicle body for intake of air into the engine compartment. A grain bin forward of the engine compartment includes a grain bin extension skirt mounted above the grain bin. An intake housing is mounted over the air inlet in the vehicle body side and includes a forwardly extending portion mounted alongside the grain bin extension with an inlet opening oriented so as draw air primarily from an area forward of the engine compartment and above the vehicle body.

A grass cutting machine with two cutting units mounted on opposite sides of the chassis has an inclinometer monitoring the left/right inclination of the chassis. If the inclination value exceeds a defined threshold, the higher of the two cutting units is lifted to improve stability.

An agricultural working machine has a one control/regulating unit designed to adjust and monitor working parameters, quality parameters or both of the agricultural working machine that influence a harvesting process. The adjusting and monitoring are carried out in an automatable manner by the control/regulating unit using stored families of characteristics. The agricultural working machine also has at least one display device for depicting setpoint values and actual values of the working parameters, quality parameters or both. The control/regulating unit actuates defined measurement points in the stored families of characteristics and the specifically actuated measurement points are located in the boundary regions of the family of characteristics or outside the active working region of the particular family of characteristics.

A harvesting machine for threshing crop materials includes a platform supported in front of a chassis, an erecting device having a number pairs of guiding bars attached to the platform and having a channel formed between two bar members of each pair of guiding bars, a guiding element disposed between every two adjacent pairs of guiding bars for guiding a stalk of the crop materials into the channel of the guiding bars, a number of pawls extended into the channel for sending the stalk of the crop materials into the channel, and a cutting device having two or more cutting elements for cutting the stalk into a lower base segment that carries no grain and an upper straw segment that carries grains.

A windguard mechanism comprising a pair of arms attachable to an agricultural machine and a windguard plate extending between the pair of arms and positioned to hold down crop material processed by a pickup mechanism. The windguard plate comprises a first plate fixed between the pair of arms and a second plate positioned movably with respect to the first plate, wherein working surfaces of the first plate and of the second plate form a windguard working surface of an area independent on the position of the second plate.

A terminal attaching/detaching device includes a housing, an engaging member, and a movable member. The engaging member is configured to move in a first direction toward a terminal inserted in the housing to engage with the terminal, and is configured to move from the terminal inserted in the housing in a second direction to disengage from the terminal. The movable member is configured to move in concert with the engaging member in the moving process thereof in the first direction, and is configured to move the engaging member from the terminal inserted in the housing in the second direction, so that the engaging member is disengaged from the terminal.

A method and apparatus is disclosed herein for improved switching speed and/or tunability for radio-frequency (RF) devices are described. In one embodiment, a liquid crystal (LC) component comprises an LC structure in a mixture with right-handed (R) and left-handed (S) chiral dopants.

The present invention provides a combination showerhead with press button switching comprising fixing holder, two showerheads and switching mechanism. The first showerhead is mounted to fixing holder; fixing holder comprises an inlet passage and two diversion passages. The switching mechanism comprises diversion plate, transmission mechanism, sliding block and press button. Diversion plate is connected to fixing holder movably and cooperated with inlet and diversion passages to switching waterway by predetermined angle rotating. Sliding block is slidably connected to fixing holder; the transmission mechanism is connected between the diversion plate and the sliding block in transmission way so that back-and-forth sliding of sliding block drives diversion plate to rotate step-by-step in predetermined angle. Press button is movably connected to fixing holder and connected to sliding block in transmission way to drive sliding block to slide. The combination showerhead is novel and convenient for one-handed operation with reasonable layout and compact structure.

An interactive image matching game and method of play. The matching game includes a plurality of expression cards each having a first indicia indicating a descriptive word and a plurality of sheets of paper each having a second indicia showing a partial image. In play, a player selects an expression card and then completes a first picture incorporating the second indicia within the first picture. The player places the first picture in a secret container and selects a second picture drawn by a second player from the container. The first player guesses the identity of the second player based on the second picture. Further, the first player guesses the word displayed on the expression card received by the second player based on the second picture. Points are acquired with correct guesses. A timer is used to account for a duration in which a player has to complete a first drawing.

The disclosure refers to a control device and method for an intelligent basketball shooting machine, the device includes a control module, a blue-tooth communication module, a display module, a control switch, a power-supplying module, and a first sensor and a second sensor both for counting; the first sensor is used for catching amount of goals in one basket of basketball shooting machine, and the second sensor used for catching amount of goals in another basket of basketball shooting machine; the first sensor, second sensor, blue-tooth communication module, display module, control switch and power-supplying module are respectively connected with control module; the disclosure makes the basketball shooting machine go on single game or online game, besides, the player can play the shooting game with friends by remote way just through an intelligent terminal, which increases interest and convenience.

For analog-to-digital converters (ADCs) which utilize a feedback digital-to-analog converter (DAC) for conversion, the final analog output can be affected or distorted by errors of the feedback DAC. A digital measurement technique can be implemented to determine switching mismatch error for the feedback DAC in a continuous-time delta-sigma modulator (CTDSM) or in a continuous-time pipeline modulator. The methodology forces each DAC unit elements (UEs) to switch a certain amount times and then use the modulator itself to measure the errors caused by those switching activities respectively. The obtained errors can be stored in a look-up table and fully corrected in digital domain or analog domain.

System and methods for input path matching in pipelined continuous-time Analog-to Digital Converters (ADCs), including pipelined Continuous-Time Delta Sigma Modulator (CTDSM) based ADCs, includes an input delay circuit disposed in a continuous-time input path from an input of an analog input signal to a first summing circuit of the continuous-time ADC. At least one digital delay line is disposed between an output of an earlier stage sub-ADC (of a plurality of pipelined sub-ADCs) and a sub-digital-to-analog converter (DAC) that is coupled to the first summing circuit, and between the earlier stage sub-ADC and a digital noise cancellation filter. The digital delay line(s) is configured to enable calibration of delay of output of the earlier stage sub-ADC provided to the sub-DAC and the digital noise cancellation filter in accordance with process variations of the input delay match circuit to minimize residue output at first summing circuit.

The present invention ensures reliability while reducing the size of an axial air gap rotating electric machine. An axial air gap rotating electric machine has: a stator comprising a plurality of core members arranged in a ring shape, said core members each having an iron core, a coil wound in an iron core outer periphery direction, and a bobbin disposed between the iron core and the coil; and a rotor plane-facing an end surface of the iron core via an air gap in a rotating shaft radial direction. The bobbin has: a tubular portion facing the outer peripheral side surface of the iron core and shorter than the length of the iron core; flange portions extending in the vicinity of both ends of the tubular portion from the outer periphery of the tubular portion toward the vertical direction outside by a predetermined length; and a projection portion being on the outside surface of at least one of the flange portions and near the inner edge of the tubular portion, having an inner peripheral surface facing the end outer peripheral side surface of the inserted iron core, and further projecting in an extending direction of the tubular portion.

An electric machine comprising a first carrier having an array of electromagnetic elements and a second carrier having electromagnetic elements defining magnetic poles, the second carrier being arranged to move relative to the first carrier. An airgap is provided between the first carrier and the second carrier. The electromagnetic elements of the first carrier include posts, with slots between the posts, one or more electric conductors in each slot, the posts of the first carrier having a post height in mm. The first carrier and the second carrier together define a size of the electric machine. The magnetic poles having a pole pitch in mm. The size of the motor, pole pitch and post height are selected to fall within a region in a space defined by size, pole pitch and post height that provides a benefit in terms of force or torque per weight per excitation level.

An electric machine of a motor vehicle, in particular of an adjustment drive or of a radiator fan, has a rotor which is mounted so as to be rotatable about a machine axis. The rotor has a number of permanent magnets which are arranged in the radial direction. Each permanent magnet has one side with a strong magnetic flux and one side with a weak magnetic flux in the tangential direction. When the permanent magnets are adjacent in the tangential direction, different sides are directed towards one another.

Raw material magnet is milled to magnet powder, and the magnet powder thus milled is mixed with a binder to form a compound 12. Then, the compound 12 thus formed is molded to a green sheet 14 having a sheet shape. Thereafter, a magnetic field orientation is carried out by applying a magnetic field to the green sheet 14 thus molded, and then, the green sheet 14 having been subjected to the magnetic field orientation is shaped to a product shape by deforming thereof. Thereafter, the permanent magnet 1 is produced by sintering thereof. The permanent magnet 1 has a ring shape, and is constituted such that an axis of easy magnetization may be orientated at a slant so as to converge in a direction along a converging axis P which is set to a radius direction as well as to a center direction of the ring shape.

The invention provides a rotating electrical machine system in which an air volume of a refrigerant is increased near the center of a rotating electrical machine in the axial direction is improved. The rotating electrical machine includes a rotor and a stator, in which the stator core, laminated electromagnetic steel sheets formed by laminating a plurality of electromagnetic steel sheets in the axial direction are divided into a plurality of sets of packet cores, and between one of the packet cores of the plurality of sets and another packet core adjacent to it, there is formed a duct providing a flow channel of the stator, and in a duct situated at the center side from both ends in the axial direction among the duct, there is a portion of two packet cores facing each other across the duct, a diameter direction length of the two packet cores becoming long.

The invention relates to an electric machine (10) with commutating brushes (12) and an electric interference-suppression component (14). The brushes (12) are arranged in an annular brush support (18), and the brush support (18) sits on an axial end (22) of a housing part (24) of the electric machine (10), which is preferably a pole housing (240). The interference-suppression component (14) is arranged radially outside of the housing (24), and the brush support (18) has a protrusion (30) which extends in the radial direction (2). The protrusion (30) extends radially towards the outside so as to extend outside of the housing (24), the interference-suppression component (14) being arranged on the protrusion (30).

A music machine, comprising: a platform; a plurality of arcos disposed around a perimeter of the platform, the plurality of arcos disposed in a substantially vertical orientation; a central mast disposed substantially at a center of the platform; and a hand wheel disposed on the central mast, wherein each of the plurality of arcos is strung with a musical instrument string, and wherein each musical instrument string is tuned to produce a musical tone when caused to vibrate.

[Problem] To provide a marching drum which ensures forwards and downwards visibility and ensures the field of view during marching. [Solution] [Effect] By eliminating all or some members of the body of the drum, or by adopting transparent members, this marching drum which enables forwards and downwards visibility ensures the performer's field of view during marching.

The present invention provides in one aspect for a bracket for use with insulated forms for concrete walls. The bracket has an attachment plate for overlying the exterior of the insulated form to provide for a means of attaching the header or rim joist to the bracket. The bracket is provided an anchoring plate extending from the attaching plate for insertion into the interior of the insulated form. The present invention also provides for a method of attaching a header or rim joist to a concrete wall formed using insulated forms. The method involves cutting a vertical slot in the insulated form and inserting a bracket into the slot. The bracket has an attachment plate for overlying the exterior surface of the insulated form and an anchoring plate extending from the attachment plate through the slot into the interior of the insulated form. Concrete is poured into the form and allowed to set, after which the header or rim joist is attached to the brackets.

An incremental forming machine binder is provided that has a blank holding opening that may be subdivided into smaller blank holding openings. The opening is subdivided by one or more clamping modules that are connected by connecting modules to each other and the frame. Clamps are attached to the clamping modules to clamp blanks in the blank holding openings. Multiple blanks may be secured to the binder for incremental forming.

An infusion pump system providing therapy to a patient in a closed-loop or semi-closed loop mode can safely automatically revert to open-loop therapy. The system stores a default open-loop basal rate profile in memory. The system also continually tracks the insulin on board for the patient over a plurality of closed-loop therapy intervals. When an error or event occurs requiring reversion to open-loop therapy, the system automatically provides therapy according to the open-loop basal rate profile and the tracked insulin on board amount.

An abnormality detecting apparatus (10) for a rotating machine includes: a calculating part (15) which calculates a phase difference between signals respectively output from two sensors of one or more sets, the one or more sets being predetermined combinations of two sensors among the plurality of sensors, the plurality of sensors each of which detects an elastic wave generating in the rotating machine (1) having a rotor during rotation of the rotor, the sensors being arranged at predetermined different locations of the rotating machine (1); a storing part (16) which stores in advance information concerning a relationship between a phase difference and a contact position when a contact occurs during the rotation of the rotor, regarding the one or more sets; and a specifying part (17) which specifies a contact position by using a phase difference calculated by the calculating part (15) and the information stored in the storing part (16).

A sensor arrangement with a sensor element for measuring at least one physical and/or chemical fluid characteristic in a turbomachine is provided. The sensor element detects the at least one fluid characteristic inside a non-contact seal, in particular a labyrinth seal, between a rotor stage and a stator stage, wherein during operation the sensor element is in contact with the fluid flow along the flow path inside the labyrinth seal.

A switching regulator control circuit is used in a switching regulator that converts an input voltage into an output voltage by the switching of a switching device, and generates a switching signal for controlling the ON/OFF operation of the switching device. The switching regulator control circuit has a fault detector and a fault protector. The fault detector detects, based on the duty ratio of the switching signal or a variable correlated to it and included in a control signal used to generate the switching signal, a fault state where the duty ratio falls outside the normal modulation range. The fault protector stops the switching of the switching device when the fault detector detects a fault state.

In a rotary machine, a method of assembling a rotary machine, and a method of performing maintenance of a rotary machine, a combustor casing as an outer casing configured from upper and lower casings forming a half split shape, an intermediate shaft cover as an inner casing configured from upper and lower casings forming a half split shape and supporting a combustor in the combustor casing, and a pressing support mechanism that presses and supports a portion to be fit of the combustor casing and a fitting portion of the intermediate shaft cover in an axial direction of a rotor are provided, and thus, detachment of the casing is made easy and maintainability of an inside thereof is improved in the method of performing maintenance of a rotary machine.

A hydraulic system for a work machine includes a first control valve including a first direction switch to switch a direction in which the operation fluid is to flow through a first hydraulic actuator and a pressure compensator to maintain a differential pressure to a constant pressure, the differential pressure being a difference between a pressure of the operation fluid to be inputted to the pressure compensator and a pressure of the operation fluid to be outputted from the pressure compensator. And, the hydraulic system includes a second control valve including a second direction switch to switch a direction in which the operation fluid is to flow through a second hydraulic actuator and a flow rate prioritizer to prioritize a flow rate of the operation fluid to be outputted to the second hydraulic actuator.

Methods, apparatuses and systems are disclosed for chemically etching parts by generating an enclosed chemical etching chamber in contact with a part surface and directing a flow of chemical etchant solution in contact with a part region to be etched.

A surface machining method for a single crystal SiC substrate, including: a step of mounting a grinding plate which includes a soft pad and a hard pad sequentially attached onto a base metal having a flat surface, a step of generating an oxidation product by using the grinding plate, and a step of grinding the surface while removing the oxidation product, wherein abrasive grains made of at least one metallic oxide that is softer than single crystal SiC and has a bandgap are fixed to the surface of the hard pad.

A machine (1) and a method for thermobonding using an emission of electromagnetic waves (13), for example microwaves, to activate one or a plurality of adhesive layers located between a support and one or a plurality of layers of flexible covering, through a bed of particles (4) fluidized by a humidified gas. A multi-layer upholstery item including at least one non-permeable layer and produced in a single operation is also described.