Disclosed herein are abrasive grains based on zirconia alumina melted in an electric arc furnace, comprising a content of 52 to 62 wt % Al203 and 35 to 45 wt % ZrO2, wherein the high-temperature phases of the zirconia are stabilized by a combination of reduced Ti compounds and yttrium oxide.

Methods of making a superabrasive tool precursor are disclosed, along with such precursors and associated tools. Particularly, methods are disclosed for orienting superabrasive particles in a viscous binding material in order to provide tools based thereupon and having desired performance characteristics.

A low defect chemical mechanical polishing composition for polishing silicon oxide containing substrates is provided comprising, as initial components: water, a colloidal silica abrasive; and, an additive according to formula I.

Embodiments of the invention relate to polycrystalline diamond compacts (“PDCs”) comprising a polycrystalline diamond (“PCD”) table including a thermally-stable region having at least one low-carbon-solubility material disposed interstitially between bonded diamond grains thereof, and methods of fabricating such PDCs. In an embodiment, a PDC includes a substrate, and a PCD table bonded to the substrate. The PCD table includes a plurality of diamond grains exhibiting diamond-to-diamond bonding therebetween and defining a plurality of interstitial regions. The PCD table further includes at least one low-carbon-solubility material disposed in at least a portion of the plurality of interstitial regions. The at least one low-carbon-solubility material exhibits a melting temperature of about 1300° C. or less and a bulk modulus at 20° C. of less than about 150 GPa.

Embodiments of the invention relate to polycrystalline diamond compacts (“PDCs”) and methods of fabricating such PDCs. In an embodiment, a PDC includes a substrate and a preformed polycrystalline diamond table including an interfacial surface bonded to the substrate and an opposing working surface. The preformed polycrystalline diamond table includes a proximal region extending from the interfacial surface to an intermediate location within the preformed polycrystalline diamond table that includes a metallic infiltrant infiltrated from the substrate, and a distal region extending from the working surface to the intermediate location that is substantially free of the metallic infiltrant. A boundary exists between the proximal and distal regions that has a nonplanar irregular profile characteristic of the metallic infiltrant having been infiltrated into the preformed polycrystalline diamond table.

Polishing pads for polishing semiconductor substrates using eddy current end-point detection are described. Methods of fabricating polishing pads for polishing semiconductor substrates using eddy current end-point detection are also described.

The inventive method comprises chemically-mechanically polishing a substrate with an inventive polishing composition comprising a liquid carrier and abrasive particles that have been treated with a compound.

The present disclosure relates to cubic boron nitride (cBN) cutting elements that have high cBN content and that are cuttable by electric discharge machining (EDM). A cutting element according to an embodiment includes a self-sintered polycrystalline cubic boron nitride (PCBN) compact, having a first phase of cubic boron nitride (cBN) particles and a ceramic binder phase with titanium compounds. The first phase occupies greater than 80% by volume of the self-sintered PCBN compact. The self-sintered PCBN compact has an electrical conductivity sufficient to be cuttable by electrical discharge machining.

A polishing composition contains colloidal silica particles having protrusions on the surfaces thereof. The average of values respectively obtained by dividing the height of a protrusion on the surface of each particle belonging to the part of the colloidal silica particles that has larger particle diameters than the volume average particle diameter of the colloidal silica particles by the width of a base portion of the same protrusion is no less than 0.245. Preferably, the part of the colloidal silica particles that has larger particle diameter than the volume average particle diameter of the colloidal silica particles has an average aspect ratio of no less than 1.15. Preferably, the protrusions on the surfaces of particles belonging to the part of the colloidal silica particles that has larger particle diameters than the volume average particle diameter of the colloidal silica particles have an average height of no less than 3.5 nm.

The present disclosure relates to cubic boron nitride (cBN) cutting elements that have high cBN content and that are cuttable by electric discharge machining (EDM). A cutting element according to an embodiment includes a self-sintered polycrystalline cubic boron nitride (PCBN) compact, having a first phase of cubic boron nitride (cBN) particles and a ceramic binder phase with titanium compounds. The first phase occupies greater than 80% by volume of the self-sintered PCBN compact. The self-sintered PCBN compact has an electrical conductivity sufficient to be cuttable by electrical discharge machining.

An abrasive article includes an elongated body, a bonding layer including a metal overlying a surface of the elongated body, and a coating layer including a polymer material overlying the boding layer. The abrasive article further includes abrasive grains contained within the bonding layer and coating layer, and wherein the bonding layer comprises an average thickness (tbl) at least about 40% of the average grit size of the abrasive grains.

Methods for preparing a silicon bonded PCD material involving a one step, double sweep process and drilling cutters made by such processes are disclosed. The PCD material includes thermally stable phases in the interstitial spaces between the sintered diamond grains. The method sweeps a diamond powder with a binder to form sintered PCD, reacts said molten binder with a temporary barrier separating said binder and said diamond from a silicon (Si) source, and sweeps said sintered PCD with said Si source to form SiC bonded PCD.

A method for making a super-hard construction comprising a first structure comprising a first material joined to a second structure comprising a second material, in which the coefficient of thermal expansion (CTE) and Young's moduli of the materials of each material are substantially different from each other. The method includes forming an assembly comprising the first material, the second material and a binder material arranged to be capable of bonding the first and second materials together, the binder material comprising metal; subjecting the assembly to a sufficiently high temperature for the binder material to be in the liquid state and to a first pressure at which the super-hard material is thermodynamically stable; reducing the pressure to a second pressure at which the super-hard material is thermodynamically stable, the temperature being maintained sufficiently high to maintain the binder material in the liquid state; reducing the temperature to solidify the binder material; and reducing the pressure and the temperature to an ambient condition to provide the super-hard construction.

An electronic device including a signal generating circuit and a movable sensing circuit is provided. The signal generating circuit generates a sensory signal through a signal source. The movable sensing circuit generates a feedback signal in response to a detection signal from the signal generating circuit, and transmits the feedback signal to the signal generating circuit. The signal generating circuit obtains a first distance value between the signal source and the movable sensing circuit based on the feedback signal, and adjusts the intensity of the sensory signal according to the first distance value.

A Continuous Transmission Frequency Modulated (CTFM) detection apparatus is provided. The apparatus includes a projector, a sensor, and a hardware processor. The projector is configured to transmit a frequency modulated transmission wave at a given transmission period. The sensor is configured to receive a reflected wave, the reflected wave comprising a reflection of the transmission wave on a target object. The hardware processor is programmed to at least generate a beat signal based at least in part on the transmission wave and the reflected wave, extract asynchronously from the transmission period a processing signal from the beat signal, and generate information related to the target object based on the processing signal.

The present invention relates to a system for determining a distance, a transponder, a position detection apparatus, and a method therefor. The method for determining a distance comprises providing a position detection apparatus (101), and a transponder (105). The method further comprises generating (201) a pseudo number sequence, transmitting (202) the pseudo number sequence, receiving (203) the pseudo number sequence; modulate (204) the received pseudo number sequence by means of delaying the recieved pseudo number sequence a predetermined number of clock cycles from a group of at least two predetermined number of clock cycles. The method further comprises transmitting (205) the modulated pseudo number sequence, recieving (206) the modulated pseudo number sequence, detecting (207) a path time of the pseudo number sequence, by means of delaying and correlating the generated pseudo number sequence with the received modulated pseudo number sequence, wherein the delay time corresponds to the path time, The method further comprises detecting (208) a clock correction factor for the transponder (105) using the received modulated pseudo number sequence, calculating (209) a flight time of the pseudo number sequence between the position detection apparatus and the transponder by means of the path time, the clock correction factor, and the predetermined number of clock cycles of the transponder, and calculating (210) the distance between said position detection apparatus and said transponder by means of the flight time.

A method and system for estimating uncertainties in radar based precipitation estimates is provided. In an embodiment, gauge measurements at one or more gauge locations are received by an agricultural intelligence computer system. The agricultural intelligence computer system obtains precipitation estimates for the one or more gauge locations that correspond to the gauge measurements and computes the differences between the precipitation estimates and the gauge measurements. Using the precipitation estimates and the computed differences, the agricultural intelligence computer system then models a dependence of the uncertainty in the precipitation estimates on the value of the precipitation estimates. When the agricultural intelligence computer system receives precipitation estimates for a location where gauge measurements are unavailable, the agricultural intelligence computer identifies an uncertainty for the precipitation estimate based on the value of the precipitation estimate and the model of the dependence of the uncertainty on the precipitation estimate values.

Methods and devices are presented for synchronizing positioning signals in a kinematic location network. In particular, methods and devices are presented for synchronizing a unique positioning signal generated by a positioning-unit device to a reference positioning signal generated by a reference transmitter, where the positioning-unit device and the reference transmitter are moving relative to each other. In certain embodiments the reference transmitter or the positioning-unit device, or both, self-monitor trajectory data comprising one or more of location, velocity or acceleration, e.g. using inertial navigation systems, and broadcast that data in their positioning signals. The trajectory data enables estimation of Doppler shifts and propagation delays associated with the positioning signals, allowing measurement and correction of clock drift for synchronization of the positioning signals.

A dual mode electromagnetic detection system and a protective dome for the electromagnetic detection system are described. The protective dome includes a substrate having a portion transparent to both infrared radiation and radio frequency radiation. The portion of the substrate includes a macromolecular material including a polymer selected from a family of polyolefins and an antistatic additive.

An apparatus may include a plurality of antenna elements forming an antenna array. The apparatus may further include a beamformer that determines one or more of phase and amplitude shifts to cause the plurality of antenna elements to produce a beam in the direction of a target. The apparatus may further include a null limiter comprising dither circuits. The dither circuits may dither the one or more of phase and amplitude shifts by adding noise to cause a side lobe of the beam to increase above a threshold value. The dither circuits may be enabled by a control signal, and the dithered one or more of phase and amplitude shifts may be provided to the antenna elements to produce the beam in the direction of the target with the side lobes above the threshold value.

A vehicle-mounted radar apparatus includes transmission antenna members and a transmitting section provided with an oscillator and phase shifters, a controller controlling the phase shifter, a reception antenna member, and a receiving section. The oscillator generates radio waves for the radar waves transmitted from the transmission antenna. Each phase shifters changes a phase of the radio waves generated and supplies the phase-shifted radio waves to a corresponding one of the transmission antenna members. The reception antenna member receives reflected waves of the radar waves. The receiving section generates a reception signal including the reflected waves. For the noise reduction process, the controller controls the phase control, so that, of the received signals generated at the receiving section, a first leak component which is from reflected waves from objects other than a target object is subtracted from a second leak component leaking from the transmitting section to the receiving section.

A system is described, along with the related device and method, for transmission and/or reception of signals having electromagnetic modes with orbital angular momentum (OAM), wherein the device is adapted to receive, at its input, electromagnetic signals from at least one transmitter, and is configured to apply a discrete Fourier transform to the electromagnetic signals in order to generate the signals having electromagnetic modes with orbital angular momentum.

There is provided a method for positioning of user equipment. The method for positioning of user equipment, includes: receiving, by the user equipment, a signal from an external antenna, the signal being radiated in a cyclic pattern; measuring, by the user equipment, strength of the received signal, characterizing, by the user equipment, the measured strength to form a signal pattern over a time period; and determining a position of the user equipment based on the signal pattern.

A method is disclosed for determining the position of an RFID transponder. Separate signals of at least two electromagnetic alternating fields are emitted from at least two antenna to one RFID transponder. The antenna are spaced at a distance from each other so that the two electromagnetic alternating fields are emitted at a distance from one another. The emitted electromagnetic alternating fields to the one RFID transponder are reflected so that the reflected electromagnetic alternating fields are sent back to the antenna. The transit times of the electromagnetic alternating fields are determined from emission to receiving back at the antenna. The distances between the antenna and the RFID transponder are determined, and the position of the RFID transponder from the at least two distances is determined relative to the at least two antenna.

A system comprising: an interrogator device, comprising: a first transmit antenna configured to transmit radio-frequency (RF) signals circularly polarized in a first rotational direction; and a first receive antenna configured to receive RF signals circularly polarized in a second rotational direction different from the first rotational direction; and a target device, comprising: a second receive antenna configured to receive RF signals circularly polarized in the first rotational direction and a second transmit antenna configured to transmit, to the interrogator device, RF signals circularly polarized in the second rotational direction.

A radar sensor for detecting at least one object, having a control device to receive a control input signal; a signal generator to generate a transmit signal having a multitude of signal cycles, each signal cycle having a multitude of signal sequences, and a series of blocks being formed, each block having precisely one frequency ramp of each signal sequence, and the signal generator furthermore being designed to select a predefined quantity of blocks from the transmit signal based on the control input signal and to output them as output signal; an antenna device to transmit the output signal that is output by the signal generator and to receive a receive signal; and an evaluation device which is designed to ascertain, by superpositioning the transmit signal and the receive signal, a quantity with regard to an angle and/or a distance and/or a relative speed of the at least one object.

A radar apparatus generates a strength distribution indicating a correspondence relationship between a relative speed parameter related to an observation point relative speed and a reflection strength parameter related to reflection strength of radar waves reflected at an observation point, for a plurality of observation points. Furthermore, the radar apparatus determines that a traveling vehicle is detected when the reflection strength parameter decreases as the relative speed parameter increases from a center relative speed parameter that is the relative speed parameter corresponding to a peak in the reflection strength, the reflection strength parameter decreases as the relative speed parameter decreases from the center relative speed parameter, and a distribution of the reflection strength parameter is symmetrical with the center relative speed parameter at the center.

In one embodiment, a radio altimeter tracking filter is provided. The filter comprises: a wireless radio interface; a processor coupled to the wireless radio interface; a memory coupled to the wireless radio interface; wherein the wireless radio interface is configured to wirelessly receive a radio altimeter signal and convert the radio altimeter signal to a baseband frequency signal, wherein the a radio altimeter signal sweeps across a first frequency spectrum between a first frequency and a second frequency; wherein the processor is configured to pass the baseband frequency signal through a filter executed by the processor, the filter comprising a passband having a first bandwidth, and wherein the filter outputs a plurality of spectral chirps in response to the baseband frequency signal passing through the first bandwidth; wherein the processor is configured to process the plurality of spectral chirps to output characteristic parameters that characterize the radio altimeter signal.

A first method includes receiving a first reflected radar signal from a target in a first field of view and receiving a second reflected radar signal from a target in a second field of view offset from the first field of view by a predetermined distance; transforming the first and second reflected radar signals to obtain first and second sets of frequency coefficients, from which a frequency-dependent phase difference is obtained; and calculating a time-delay from the slope of the frequency dependence. A second method includes obtaining summed difference values between the first and second radar responses, where each of the summed difference values corresponds to different time shifts between the first and second radar response, and deriving from the summed difference values a time-delay associated with the target's motion from the first field of view to the second field of view. A third method combines the time-delays or associated speeds obtained from independent estimators.

A blind spot detection system for a motorcycle, which includes an accelerometer, a gyroscope, and a detection device for detecting the presence of a vehicle in at least one blind spot. The accelerometer detects a gravity force vector, and the gyroscope detects the position of the motorcycle relative to the gravity force vector such that a lean angle of the motorcycle is calculated. The detection device is then configured to maintain the same position of the motorcycle relative to the gravity force vector and compensate for the position of the motorcycle if the lean angle is greater or less than 90°, such that the detection device is able to detect the presence of the vehicle in the at least one blind spot, independent of the lean angle of the motorcycle.

The invention relates to determining the presence of flowing water (B) in the vicinity of a vehicle. It relies on a pair of sensors (6a) emitting periodic signals, receiving reflected signals and comparing them to each other to determine the presence of flowing water in the area surrounding the vehicle. Another approach relies on a single sensor and analyses perturbations in the signal of said sensor. Preferably, the invention uses sensors already installed, namely parking sensors and a radar.

A radar apparatus detects an observation point distance and an observation point azimuth. In addition, the radar apparatus calculates an observation point lateral position and an observation point vertical position based on the observation point distance and the observation point azimuth. Furthermore, the radar apparatus determines that a traveling vehicle is detected when a number of observation points included within a side determination range is equal to or greater than a predetermined traveling vehicle determination count, based on the observation point lateral position and the observation point vertical position. The side determination range is set so as to include a passing determination line so as to extend in a direction at 90 degrees relative to a front-rear direction of the vehicle to the side of the vehicle.

A portable terminal includes a GPS unit configured to receive a GPS signal, a GPS processing section configured to detect GPS accuracy at an interval and detect the position of a vehicle on the basis of the GPS signal received by the GPS unit, and an information processing section configured to detect entrance timing, which is timing when the GPS accuracy is detected when the vehicle is located at an entrance point of a multi-storey parking structure, on the basis of transition of the GPS accuracy detected by the GPS processing section at the interval.

A terminal for identifying a location of a user includes a transmitter configured to transmit data, a receiver configured to receive the data, a sensor configured to sense at least one piece of context information, and a controller configured to determine a priority order of area information, service set identifier (SSID) information, global positioning system (GPS) signal information, and the context information corresponding to each location, identify the location based on the priority order, and determine the priority order of the SSID information and the GPS signal information in response to retrieving a number of SSIDs.

Various methods, apparatus, devices and systems are provided for electrically short antennas for efficient broadband transmission. In one example, among others, a system includes a segmentally time-variant antenna and a segment controller that can control conductivity of individual segments of the segmentally time-variant antenna. The conductivity of the individual segments is modulated to allow a pulse to propagate from the proximal end to the distal end of the segmentally time-variant antenna and impede a reflection of the pulse from propagating back to the proximal end of the segmentally time-variant antenna. In another embodiment, a method includes injecting a pulse at a first end of a segmentally time-variant antenna and modulating conductivity of individual segments to allow the pulse to propagate to a second end of the segmentally time-variant antenna and impede a reflection of the pulse from propagating back to the first end.

Disclosed are systems and methods for improving the quality and strength of a wireless signal connecting a mobile station and a base station, in situations where the mobile station is able to utilize a directional antenna. The system for improving system quality comprise, for example, a directional antenna; an antenna power level detector which detects a signal strength; a signal inverter wherein the signal inverter generates a conditioned signal from the detected signal strength; an indicator wherein the indicator provides an indicator of a signal quality level from the detected signal strength; a reorientation decision logic wherein the reorientation decision logic communicates an instruction for movement of the directional antenna, wherein the detected signal strength is correlated to a projected orientation of the directional antenna at a time the signal strength is detected, and further wherein an antenna orientation control loop communicates a reorientation instruction for the directional antenna.

Described embodiments provide sidelobe cancellation for Simultaneous Transmit and Receive systems. The sidelobe cancellation system includes an array having a primary aperture and an auxiliary array. The auxiliary array includes a plurality of antenna elements disposed adjacent to at least one side of the primary aperture. Each element of the auxiliary array is coupled to a variable attenuator, a variable phase shifter or a variable true time delay unit. A controller tunes the auxiliary array to cancel sidelobes of the primary aperture by adaptively selecting an attenuation value of the variable attenuator, a phase shift value of the variable phase shifter and a time delay value of the variable true time delay unit for each element of the auxiliary array. The auxiliary array operates as an adaptive finite-impulse response (FIR) filter with each antenna element of the auxiliary array operating as an adaptive tap of the adaptive FIR filter.

A base station including: a memory, and a processor coupled to the memory and the processor configured to: estimate a plurality of angles of arrival based on a plurality of received signals from a plurality of wireless device respectively, each of the plurality of angles of arrival being an angel of a horizontal plane relative to each direction from which each of the plurality of received signals arrives, and control at least one tilt angel based on the plurality of angels of arrival, each of the at least one tilt angle being an angle of the horizontal plane relative to each direction to which at least one beam is formed.

A fill level measurement device for determining a topology of a filling material surface in a container including an antenna apparatus, a receiver and control circuitry. An emission angle of the antenna apparatus and a spatial position of the antenna apparatus relative to the filling material surface is settable by the control circuitry. A resultant emission direction of the fill level measurement device is changeable by the control circuitry by controlling a position of the antenna apparatus and by controlling an emission and/or receiving angle of the antenna apparatus.

A sensor includes a reception antenna, a parasitic antenna terminating in a variable load, a controller, a transmitter transmitting a transmission signal, a receiver, a memory, and a processor. The controller sets an impedance value of the variable load. The receiver receives a first signal formed of signals received by the antennas and derived from the transmission signal, and the signal received by the parasitic antenna corresponding to the impedance value. The memory stores a first signal strength value of the first signal corresponding to the impedance value. The processor sets candidates of a complex propagation channel, calculates second signal strength values of a second signal respectively corresponding to the candidates, estimates a target complex propagation channel by selecting a candidate corresponding to a minimum difference among differences between the first signal strength value and the second signal strength values, and estimates a direction of arrival of the first signal.

Disclosed is a system for determining a protection level. The system includes a receiver configured to receive an error augmentation for a satellite orbit and clock error, an error augmentation for an ionospheric error, an error augmentation for noise and multi-path between a receiver and a satellite, and an error augmentation for a tropospheric error, a first calculator configured to calculate a first adjustment coefficient to be applied to the error augmentation for the satellite orbit and clock error and the error augmentation for the ionospheric error, and a second calculator configured to calculate a protection level by applying the first adjustment coefficient.

An electronic device includes an antenna including an antenna electrode, a circuit substrate, and a short-circuit portion short-circuiting the antenna electrode and the circuit substrate, a display unit, a case accommodating the antenna and the display unit, and a band connected to the case. In the short-circuit portion, a width in a direction intersecting a line segment binding a position of the short-circuit portion connected to the antenna electrode and a position of the short-circuit portion connected to the circuit substrate is narrower than a maximum width of the antenna electrode and a maximum width of the circuit substrate in a direction oriented along the intersection direction.

A vehicle cooperative object positioning optimization method and comprises steps of: receiving an information package by the local vehicle and the information package having a vehicle original coordinate and at least one object original coordinate provided by a neighbor vehicle respectively including different positioning accuracies; performing a time delay compensation for the vehicle original coordinate and the object original coordinate to acquire a vehicle coordinate and an object coordinate of the neighbor vehicle respectively; performing an optimizing procedure to optimize the vehicle coordinate and the object coordinate respectively so as to obtain the vehicle optimized coordinate and the object optimized coordinate. Therefore, the vehicle optimized coordinate and the object optimized coordinate include higher accuracy than the coordinate information detected by the GPS receiver so as to determine precisely a distribution of the environmental objects and enhance driving safety.

An aircraft communications system may include a RF-transparent enclosure, a plasma antenna element and a controller. The RF-transparent enclosure may be disposed substantially conformal with a portion of the aircraft. The plasma antenna element may be housed within the RF-transparent enclosure. The controller may be operably coupled to the plasma antenna element to provide control of operation of the plasma antenna element. The plasma antenna element may include one or more RF-conductive plasma devices that are selectively ionized to a plasma state under control of the controller.

An apparatus consisting of hierarchically elaborated antenna modules is calibrated by steps. Although the AWV can be calculated mathematically based on the required phase shift values of each antenna element for a beam direction to compensate for signal delay. However, in practice, due to hardware implementation imperfection, coupling in signal path for each antenna element within hardware, inaccuracies of implementations, physical misalignment, the mathematically generated AWV does not necessarily provide alignment between transmit beam and receive beam. This subset is sufficient is all practical operation. The subset of AWVs are typically called codebook and the receiver beam points to different direction by using a AWV within the codebook.

A process writes phase shift error correction values into a phased-array antenna to normalize a range of manufacturing variances. An axial ratio is determined for an antenna weight vector (AWV) by making multiple measurements with the horn of a test antenna mechanically rotating from 0 to 180 degree or with dual polarization test antenna. For calibration of the whole array, each subarray is treated in the same fashion as equivalent to an antenna element in the subarray calibration. The subarray is electronically rotated as a whole (all elements rotated by the same phase shift value) from 0 to 360 degree during the full array calibration. Due to small power variation among AWVs, calibration solely by REV results fail to consistently converge to resolution. Accordingly, the apparatus measures and compares axial ratios. During final fabrication, the apparatus programs an AWV with best axial ratio into each non-transitory array element.

A radio communication device including a memory and a processor coupled to the memory and the processor configured to determine a method, among a plurality of methods for beam forming, to be used for forming a first beam for a first terminal and a second beam for a second terminal based on a difference between an emitting direction of the first beam, to be formed, from the radio communication device and an estimated direction of the second terminal from the radio communication apparatus, the estimated direction being estimated based on a received signal from a second terminal, and form the first beam and the second beam based on the determined method.

An irrigation device comprising a moisture responsive barrier is provided. At least a portion of the barrier has perforations, at least some of the perforations are associated with a water swellable material. The perforations are configured to open as the water swellable material loses moisture and dries out and are configured to close as said water swellable material is exposed to and absorbs water, such as during a watering step. According to another aspect the irrigation method includes the steps of positioning a perforated barrier between a source of irrigation water and an area to be irrigated, wherein the perforations are associated with a water swellable material; exposing the water swellable material to water to cause the water swellable material to swell to close the perforations; and permitting the water swellable material to dry, to open the perforations, whereby the opening and closing of the perforations regulates the amount of irrigation water being applied across the barrier in the irrigation method.

The present invention provide a light-scattering fluororesin film for agricultural applications which can be used as a covering material for an agricultural house or the like, is excellent in uniformity of color or the like of crops cultivated, can reduce the occurrence of leaf scorch, seedling blight or the like, and can cultivate the crops at high productivity. Specifically, the invention provides a light-scattering fluororesin film for agricultural applications that gives a ratio of scattered light with a scattering angle of 5.5 to 10° being 5% or higher relative to the total transmitted light.

The present invention discloses an apparatus to simplify an air supply path without damaging the merit of conventional culture apparatus. The apparatus is a culture apparatus which includes a row of a plurality of box-shaped containers for plant cultivation, and a row of lower stage containers arranged in the lower portion of the row, holding the upper stage container spaced as high as the height after growth of the plants to be cultivated. In each container, a support, a blocking film stretched between front and rear, right and left supports of the container are provided. In the one end of the rows of the containers, an air conditioner is arranged, and in another end, a turnaround chamber is provided.