Abstract: A computer-implemented method for scanning and obtaining points of an object is provided. The method includes defining a measuring distance between two points of an object and scanning the measuring distance according to an optimal measuring position. If coordinate values of each of the scanned points are valid, then the method send the obtained coordinate values to an electronic device if the obtained coordinate values are valid.

Abstract: Active 3D triangulation-based imaging comprises steps of: temporally modulating a radiant flux of a lighting unit beam by a binary modulation signal (ms); illuminating a scene (S), which is illuminated by an ambient lighting (AL), by said modulated lighting unit beam (mlub); splitting a ray (ir) imaging a scene point (SP) into two separate imaging rays (ir1, ir2); said first separate imaging ray (ir1) forming an image in a first image sensor (is1); temporally modulating a radiant flux of the second separate imaging ray (ir2) by the modulation signal (ms) and said modulated second separate imaging ray (ir2m) forming an image in a second image sensor (is2); normalizing a first scene image being an image of all points of the scene (S) formed in the first sensor (is1) and a second scene image formed in the second sensor (is2); and subtracting the first normalized scene image from the second normalized scene image.

Abstract: A project calculator, including a housing, a circuit board mounted within the housing and including a processor, an input device connected to the circuit board and interfacing with the processor, an output device connected to the circuit board and interfacing with the processor, and a distance sensor rotatably mounted to the housing and interfacing with the processor. A laser assembly is may also be rotatably mounted to the housing and configured to provide a visual indicator to an object to which the distance sensor is pointing. One or more level indicators may also be mounted to the housing.

Abstract: Specific wavelengths to use in optical metrology of an integrated circuit can be selected using one or more selection criteria and termination criteria. Wavelengths are selected using the selection criteria, and the selection of wavelengths is iterated until the termination criteria are met.

Abstract: Embodiments of the present invention address deficiencies of the art in respect to equipment position location in a data center and provide a novel and non-obvious method, system and computer program product for rack position determination using acoustics. In one embodiment of the invention, a method for rack position determination using acoustics can be provided. The method can include ultrasonically ranging a first target wall in a data center from a host rack enclosure to acquire range data for the first target wall and ultrasonically ranging a second target wall in the data center from the host rack enclosure to acquire range data for the second target wall. The method further can include translating the range data for the first target wall and second target wall into position coordinates for the host rack enclosure and forwarding the position coordinates to a system administrator for the data center over a coupled data communications network.

Abstract: In a method of determining a structure parameter of a target pattern in a lithographic process, a series of calibration spectra are calculated from a reference pattern. Spectral analysis is performed on each calculated spectra, the spectral components and associated weighting being derived and stored in a library or used as the basis of an iterative search method. A spectrum is measured from the target pattern and spectral analysis of the measured spectrum is performed. The derived weighting factors of the principal components are compared with the weighting factors of the measured spectrum to determine the structure parameter.

Abstract: The invention relates to a method for determining the size of a radial gap between rotating and torsion-proof parts, particularly the parts of a turbomachine. According to said method, an original signal emitted by a transmitter device located on the surface of the rotating part is received in a modified manner by a receiver device disposed on the torsion-proof part and is redirected to an evaluation unit. Said evaluation device determines and displays the size of the radial gap from the received signal by determining the parameters of the trajectory of the rotating transmitter device.

Abstract: A three-dimensional position-measuring apparatus comprises a body, a rotational optical portion rotatable with respect to the body in a horizontal direction and comprising a reflective plate in which deflection in a vertical direction is controllable, a first data transmitting and receiving portion arranged in the body and comprising a first coil which has a rotational axis of the rotational optical portion as an axis, and a second data transmitting and receiving portion arranged in the rotational optical portion and comprising a second coil that has the same axis as that of the first coil and magnetically couples with the first coil.

Abstract: Distances to targets (2a, 2b) are simultaneously determined in a method for measuring distance according to the phase measuring principle with a time discrete emission of periodic signals (7) and a sampling of received signals for generating and optionally storing sampled values, whereby the signals have signal portions that are reflected by the targets (2a, 2b) and superimposed. A statistical parameter estimation problem based on a mathematical signal model is solved in such a manner that the number of the targets (2a, 2b) for more than one target (2a, 2b) is preset or fundamentally, the number of targets is determined by the method, and the inequalities D??Dk<D+ and 1?k?K are valid. The preset distances D??R and D+?R with D?<D+ set the measuring range of the distance measuring device.

Abstract: A method and apparatus for analyzing a surface of a test object employs apparatus with a scanning interferometry system which generates a windowed interferometric signal from the surface of a test object to characterize the surface of the test object.

Abstract: To provide a monitoring device which can detect conditions of a sleeping person reliably and which is simple. A monitoring device comprising: multiple independent distance sensors 11 installed facing different positions in a monitored target area 50 to be monitored for measuring a distance to a monitored target 2, a calculating unit 22 for calculating changes over time in the outputs of the distance sensors 11, and a detection processor 23 for detecting changes in shape of the monitored target 2 based on the calculated changes over time in one or multiple distance sensor 11 among the multiple distance sensors 11.

Abstract: A non-contacting deviation measurement system projects a first line and a second line upon a surface of an object. The projections of the first line and second line are arranged to overlap at an intersection line oriented at a nominal location such that when the surface is oriented at the nominal location, the intersection line appears on the surface. As the location of the surface deviates from the nominal location, the first line and second line as projected upon the surface move away from one another. The distance between the lines may be used to calculate the deviation from the nominal location. The deviation calculated may be compared to a predetermined maximum allowable deviation.

Abstract: A laser light receiver is provided with an integral laser distance measurement (LDM) device for measuring the distance from a laser plane of a desired elevation to a desired physical target point to be measured on a jobsite. The laser receiver can be combined with a gravity reference device, so that the laser receiver does not necessarily have to be held plumb to a desired target point, when determining the relative elevation of the laser receiver between a rotating beam of laser light and the target point; it can also acquire multiple samples of positions and automatically take a vertical measurement and store that result for later readout. The laser receiver can be further combined with a GPS receiver, to acquire latitude and longitude data, and then in combination act as a three-dimensional transducer that is more accurate in the vertical direction than a GPS receiver alone is capable of.

Abstract: Methods and apparatus for spectrum-based endpointing. An endpointing method includes selecting two or more reference spectra. Each reference spectrum is a spectrum of white light reflected from a film of interest on a first substrate and has a thickness greater than a target thickness. The reference spectra is selected for particular spectra-based endpoint determination logic so that the target thickness is achieved when endpoint is called by applying the particular spectra-based endpoint logic. The method includes obtaining two or more current spectra. Each current spectrum is a spectrum of white light reflected from a film of interest on a second substrate when the film of interest is being subjected to a polishing step and has a current thickness that is greater than the target thickness. The method includes determining, for the second substrate, when an endpoint of the polishing step has been achieved.

Abstract: A billing system for determining package transportation charges. The billing system includes a reader to read a package identifier associated with said package and the reader generates a package identifier signal and transmits the same to a microprocessor. The billing system also includes a package sizer having a plurality of non-contact optical sensors located along each of an x, y and z axis, where each optical sensor is in a known position. The sensors are oriented relative to the conveyor so that packages passing over the sensors are detected by the sensors and produce a signal correlated to said package size. Also provided is a microprocessor to receive and correlate said package size and identifier signals, and to determine an appropriate shipping charge based upon the same. A weigh scale may also be incorporated into the system. A method of determining a transportation charge is also comprehended, which includes a selfdiagnostic initialization procedure.

Abstract: The present invention provides a profiling device 10 comprising an emitter arranged to emit a pulse of electromagnetic radiation towards a remote surface; a detection means arranged to receive the pulse of electromagnetic radiation once reflected from said remote surface; means 16 for altering a direction from which successive pulses of electromagnetic radiation are emitted from said profiler to cause successively emitted pulses of electromagnetic radiation to be emitted in a plurality of different directions in the same plane throughout 360 degrees; an elapsed time measuring device for measuring the time between emission of a pulse of electromagnetic radiation in one of said plurality of different directions and reception of said pulse of electromagnetic radiation reflected from said remote surface; storage means for storing measured elapsed time data; and means 22, 24 for defining a reference position for indicating when said pulses of electromagnetic radiation have been emitted over the said 360 degrees.

Abstract: Apparatus for determining distance comprising a transmitting unit for emitting a light pulse, a receiver matrix having at least one photoelectric element and a control unit, wherein the receiver matrix has a first and a second integrator which are connected to the photoelectric element, which are activatable independently of each other and which are each adapted to integrate a measurement signal outputted by photoelectric element over a period of time predetermined by the control unit and thereby to form an integrator state and to output the integrator state as an output signal.

Abstract: A non-contacting deviation measurement system projects a first line and a second line upon a surface of an object. The projections of the first line and second line are arranged to overlap at an intersection line oriented at a nominal location such that when the surface is oriented at the nominal location, the intersection line appears on the surface. As the location of the surface deviates from the nominal location, the first line and second line as projected upon the surface move away from one another. The distance between the lines may be used to calculate the deviation from the nominal location. The deviation calculated may be compared to a predetermined maximum allowable deviation.

Abstract: A carriage moves back and forth under a vehicle and three cameras or laser fixed along one axis pivot in a common plane, utilizing two cameras at time to locate a target fixed to a reference point on the undercarriage of the vehicle. Triangulation calculations, combined with the location of the cameras provide the location of the reference point in space in a three-dimensional coordinate system and compare that location with a stored designed location of the reference point prior to the crash, allowing the vehicle structure to be returned to its designed shape by other equipment.

Abstract: A system and method for automatically determining a seed vigor index for a lot of seeds by analysis of a scanned image of a plurality of seedlings grown from lot of seeds, including automatically separating and analyzing overlapped seedlings. According to one aspect of the current invention, seedling analysis software is used to analyze an image of seedlings. The seedling analysis software preferably analyzes both hypocotyl and radicle lengths and thus determines the separation point between the two for each seedling. The seedling analysis software also preferably separates overlapped seedlings, preferably using a simulated annealing technique. According to another aspect of the present invention, a low-cost scanner placed in an inverted configuration in a scanner enclosure is used to generate high-quality, reproducible images of seedlings. According to yet another aspect of the present invention, a method of using ordinary germination boxes, i.e.

Abstract: There is described a light extractor (8) for a light guide lamp (1) whose useful surface, that is to say, the surface that, in use, faces the emission surface (5) of the light guide lamp (1), comprises a predetermined distribution of diffusing points (10) and a complementary distribution of reflecting points (9). The light extractor (8) allows obtaining an illumination having preselected features. There are also described methods for determining such a distribution of points so as to obtain a highly uniform illumination.

Abstract: A method for generating a mask for use with a light measurement system that includes a light source for projecting light onto an object, and an imaging sensor for receiving light reflected from the object. The method includes determining a profile of the object to be inspected, and generating an electronic mask based on the determined object profile. The electronic mask has an electronic opening having a profile defined to substantially match the determined object profile as viewed from one of the light source and the imaging sensor.

Abstract: Tightening of a bolt is controlled by monitoring the change in round trip time of propagating longitudinal ultrasonic waves through the bolt and the reflection of these waves at the end of the bolt. The round trip time of the longitudinal waves through bolt is continuously measured and monitored in real-time. Elongation of the bolt as it is being tightened is determined based on the change in the round trip time of the longitudinal waves, which provides the level of bolt tension and joint clamp load. In determining the bolt elongation, an elongation-dependent wave speed has been formulated and used in-real time. When the elongation of the bolt reaches a predetermined level, tightening is automatically stopped.

Abstract: An electronic pedometer has a walk detecting sensor to detect a walking movement of a user and to output a walk signal corresponding to the walking movement. A walk judging circuit judges, based on a walk signal from the walk detecting circuit, whether or not the user is walking. A control circuit switches an operation of the walk detecting circuit from a continuous operation to an intermittent operation when the walk judging circuit judges that the user stops walking. During a continuous operation, the walk detecting circuit continuously detects a walk of the user, while during an intermittent operation the walk detecting circuit intermittently detects the walk of the user within a predetermined cycle.

Abstract: A method for monitoring consumption of a component, including the steps of emitting a radiation beam onto a first area of the component and detecting a portion of the radiation beam that is refracted by the component. A radiation level signal is generated based at least on a strength of the detected portion of the radiation beam, and a thickness of the component is determined based on the radiation level signal. The thickness of the component is compared to a predetermined thickness value, and a status signal is generated when the comparing step determines that the thickness of the component is substantially equal to or below the predetermined thickness value. When the comparing step determines that the thickness of the component is greater than the predetermined thickness value, the component is exposed to a process that can erode at least a portion of the component.

Abstract: A measurement system intended for use in the existing structures which comprises of a distance measurement device, an angle measurement device which is capable of measuring angles in two-dimensional or three-dimensional space, and a software interface which is capable of receiving, evaluating recording, transferring and processing measured angles and distances in conjunction with an array of user-defined, programmed, known, or assumed to be known angles and distances. Measurement system is to be used in conjunction with a measurement algorithm which is to be followed by the user. Measurement system records dimensional values between at least two objects within measured space as well as an angular reference between the line of sight of the measurement device and one or more reference axes of the measured space in two-dimensional or three-dimensional space in one or more operations.

Abstract: A measurement tool for use in creating a customized duct segment for connecting existing adjacent HVAC ducts. The tool includes a handheld unit and a flag, each of which is configured for mounting to a respective duct. A measuring unit, such as a laser rangefinder, of the tool is capable of measuring a linear distance between the unit and the flag, and thus between reference points on the HVAC ducts, such as corners, to which the handheld unit and flag are mounted. The tool is configured to measure and store in its memory multiple distance measurements between multiple reference points. A method of using the tool involves gathering enough measurements between enough reference points, such as corners, that the required configuration for the customized duct segment can be determined, e.g. by CAD/CAM equipment. The tool may include a data port for transmitting gathered data for CAD/CAM purposes.

Abstract: In an autostereoscopic display, a horizontal view range can be widened without reducing two-dimensional resolutions. Lenses are arranged to be a linear combination having integer coefficients of two unit vectors, thereby to control the vertical and horizontal view ranges.

Abstract: The present invention discloses the methods and apparatus to acquire, record, and analyze data to determine the draft of a water-borne vessel and/or the amount of cargo that has been loaded in a water-borne vessel. The apparatus includes a portable, handheld housing containing means for use in positioning the housing in a predetermined location and spatial orientation. Such means can include one or more narrow beam emitting devices, such as lasers or other similar devices, or a camera or other image processing level sensors. The housing also containing an ultrasonic transducer and receiver, or alternatively, a laser emitter and receiver, that directs sound pulses or light, respectively, toward the surface of the water body in which the vessel is placed. Within the housing is electrical circuitry to receive either the sound or light beam signals, and from these signals produce a signal representative of the time of travel of the sound pulse or light.

Abstract: Systems and methods are provided for detecting the potential of a wood sample, such as a board, to stay on grade, i.e., resist warp, after it is put into service and/or its moisture has re-equilibrated with the surrounding environment. The systems and methods include various sensor technologies and subjection of obtained data to various models, algorithms, and/or other mathematical formulas.

Abstract: A billing system for determining package transportation charges. The billing system includes a reader to read a package identifier associated with said package and the reader generates a package identifier signal and transmits the same to a microprocessor. The billing system also includes a package sizer having a plurality of non-contact optical sensors located along each of an x, y and z axis, where each optical sensor is in a known position. The sensors are oriented relative to the conveyor so that packages passing over the sensors are detected by the sensors and produce a signal correlated to said package size. Also provided is a microprocessor to receive and correlate said package size and identifier signals, and to determine an appropriate shipping charge based upon the same. A weigh scale may also be incorporated into the system. A method of determining a transportation charge is also comprehended, which includes a self-diagnostic initialization procedure.

Abstract: A laser light receiver is provided with an integral laser distance measurement (LDM) device for measuring the distance from a laser plane of a desired elevation to a desired physical target point to be measured on a jobsite. The laser receiver can be combined with a gravity reference device, so that the laser receiver does not necessarily have to be held plumb to a desired target point, when determining the relative elevation of the laser receiver between a rotating beam of laser light and the target point; it can also acquire multiple samples of positions and automatically take a vertical measurement and store that result for later readout. The laser receiver can be further combined with a GPS receiver, to acquire latitude and longitude data, and then in combination act as a three-dimensional transducer that is more accurate in the vertical direction than a GPS receiver alone is capable of.

Abstract: A timer survey system performing the steps of: placing a first reference point and a second reference point on a tree trunk, wherein an actual distance between the first reference point and the second reference point is a known distance, “A1”; capturing an image of that portion of the tree trunk having the reference points placed on the trunk; measuring on the image an image distance, “D1”, between the first reference point and the second reference point; measuring on the image an image distance, “D2”, between the left outer boundary and the right outer boundary of the tree trunk; and calculating an actual distance, “A2”, between the left outer boundary and the right outer boundary of the tree trunk as follows: A2=[(D2÷D1)(A1)].

Abstract: In an ultrasonic flow meter for measuring a flow rate of a fluid flowing through a conduit by detecting a propagating time difference between a forward propagating time of an ultrasonic wave propagating within the conduit in a forward direction and a backward propagating time of an ultrasonic wave propagating within the conduit in a backward direction, forward and backward ultrasonic wave signals generated by ultrasonic vibrating elements are sampled to derive forward and backward digital data series x and y, which are stored in a memory, the forward and backward digital data series x and y are read out of the first and second memory units and total sums of absolute difference values between the forward and backward digital data series x and y are calculated, while data positions of these backward and forward digital data series x and y are relatively shifted, a shift amount of data positions at which a total sum of absolute difference values becomes minimum is detected, an ultrasonic propagating time differe

Abstract: Methods are provided for estimating the dimensional stability of a wood product from simple algebraic functions of moisture, shrinkage rates and grain angles observed on outer surfaces. The methods may employ single or multiple sensor group measurements. The quantitative relationship between crook or bow stability and lengthwise shrinkage can be established using mathematical operations, rather than sophisticated and complicated finite-element modeling methods. In particular, the curvature of any board length-segment or section, expressed as the second derivative of the crook or bow profile, can be determined from a linear combination of the shrinkage values of the coupons including that segment or section. The overall crook or bow profile of the board can be determined from a section-by-section double-integration of those second derivative values.

Abstract: Counting circuits applied to distance estimation for ultra wideband (UWB) application, in which a first counting unit generates a sequence of pseudo-random number series not including zero, a first recoding unit records a first series and a second series from the sequence according to a first signal and a second signal, and a transfer unit generates a binary counting value according to the first series and second series from the recording unit.

Abstract: In a positional information detecting device, a tone-burst signal propagating unit causes a tone-burst signal to propagate through a path. The tone-burst signal is composed of a continuous wave train, the continuous wave train including a plurality of cycles of a constant frequency. A detecting unit detects, at a predetermined position in the path, the tone-burst signal propagating through the path every one cycle of the tone-burst signal to measure a propagation delay time based on the detected signal. The propagation delay time represents a period for which the tone-burst signal has propagated through the path. A phase obtaining unit obtains a phase of the detected signal. A positional information obtaining unit obtains positional information associated with the predetermined position based on the measured propagation delay time and the obtained phase of the detected signal.

Abstract: To calculate information on a relative distance or positional relationship between an interface section and an object by detecting an electromagnetic wave transmitted through the interface section, and using the electromagnetic wave from the object to detect a relative position of the object with respective to the interface section. Information on the relative spatial position of an object 101 with respect to an interface section 102 that has an arbitrary shape and deals with transmission of information or signal from one side to the other side of the interface section 102 is detected with a spatial position detection method. An electromagnetic wave 106 radiated from the object 101 and transmitted through the interface section 102 is detected by an electromagnetic wave detection section 103, and based on the detection result, information on spatial position coordinates of the object 101 is calculated by a position calculation section 104.

Abstract: A portable coordinate measurement machine for measuring the position of an object in a selected volume includes a positionable articulated arm having a plurality of jointed arm segments. The arm includes a measurement probe having an integrated line laser scanner mounted thereon. The laser may be a thermally stabilized laser.

Abstract: A method for monitoring consumption of a component, including the steps of emitting a radiation beam onto a first area of the component and detecting a portion of the radiation beam that is refracted by the component. A radiation level signal is generated based at least on a strength of the detected portion of the radiation beam, and a thickness of the component is determined based on the radiation level signal. The thickness of the component is compared to a predetermined thickness value, and a status signal is generated when the comparing step determines that the thickness of the component is substantially equal to or below the predetermined thickness value. When the comparing step determines that the thickness of the component is greater than the predetermined thickness value, the component is exposed to a process that can erode at least a portion of the component.

Abstract: Specific wavelengths to use in optical metrology of an integrated circuit can be selected using one or more selection criteria and termination criteria. Wavelengths are selected using the selection criteria, and the selection of wavelengths is iterated until the termination criteria are met.

Abstract: An apparatus includes a strap that is positional about a drill and maintains a static relationship therewith while a drill bit and chuck rotate. The apparatus includes a plurality of light sources and sensors. The light sources and sensors face forwardly and emit corresponding light arrays aligned parallel to the drill bit and measure a linear distance to a target surface respectively. Each light source defines a reflection that has a unique diameter when the drill is not perpendicular, notifying the user to adapt the drill such that identical diameters are reflected on the work surface. A mechanism communicates an output signal to a display screen so that a visual representation of the drill bit location becomes displayed on a display screen. The drill bit is aligned perpendicular to the work surface when the light sources are equidistantly spaced from the work surface.

Abstract: An interface that allows a user to model and analyze the properties of three dimensional surface and the regions surrounding such surfaces. The user manipulates a deformable bed of translucent glass beads that defines the geometry of a surface. An array of light emitting diodes underneath the beads transmits infrared light upwardly through the beads such that the intensity of radiation from each position on the surface of the beads is related to the depth of the beads at that position. A digital camera captures radiation image data which is then processed to create elevation data specifying the geometry of the surface. A processor processes the elevation data using a selected analysis function to produce result data representing computed characteristics of the surface or its surrounding region. The result data is projected as an image onto the surface of the beads. The interface permits the user to modify a surface geometry and directly visualize the characteristics of the modified geometry in real time.

Abstract: An interface that allows a user to model and analyze the properties of three dimensional surface and the regions surrounding such surfaces. The user manipulates a deformable physical modeling material that defines the geometry of a surface. A position sensor such as a laser scanner captures position data specifying the geometry of the surface. A processor processes the geometry data using a selected analysis function to produce result data representing computed characteristics of the surface or its surrounding region. The result data projected as an image onto the deformable surface. The interface permits the user to modify a surface geometry and directly visualize the characteristics of the modified geometry in real time.

Abstract: Three-dimensional parameters of a tire are measured dynamically in a non-contact way using laser vision technology. Two laser vision sensors are used, which are calibrated and then used for practical measurement. The system offers a wide measuring range, high accuracy and high efficiency, even though the tire is moving, and it minimizes the size of the measuring apparatus, and reduces the cost of the apparatus.

Abstract: An apparatus for establishing a layout of a building. The apparatus includes a mechanism for scanning a first room of the building to obtain room data. The apparatus also includes a scanner for forming a representation of a layout of the first room from the first room data. The forming mechanism is connected to the scanner. A method for establishing the layout of a building. The method includes the steps of placing a scanner in a first room of the building. Then there is the step of scanning the first room with the scanner to obtain first room data. Then there is the step of forming a representation of the layout of the first room from the first room data.

Abstract: A method of measuring a physical characteristic of a patterned substrate comprises determining a wavelength where a first reflectance from a patterned substrate equals a second reflectance from the patterned substrate. The first and second reflectances are generated from substrate regions having different pattern densities. A physical characteristic value that is associated with the determined wavelength is identified. The value identification may be done by looking up the determined wavelength in a database, for example by referring to a graph.

Abstract: A carriage moves back and forth under a vehicle and three cameras or laser fixed along one axis pivot in a common plane, utilizing two cameras at time to locate a target fixed to a reference point on the undercarriage of the vehicle. Triangulation calculations, combined with the location of the cameras provide the location of the reference point in space in a three-dimensional coordinate system and compare that location with a stored designed location of the reference point prior to the crash, allowing the vehicle structure to be returned to its designed shape by other equipment.

Abstract: A code applying device is provided which can efficiently manufacture an information recording paper roll having a code relating to the information recording paper. The code applying device includes a tubular body holding section which holds a tubular body and can rotate around an axis; a code forming section forming a code, which expresses specific information, on an end surface of the tubular body held by the tubular body holding section; and a control section rotating the tubular holding section which is holding the tubular body, and applying the code to the end surface of the tubular body along a peripheral direction.

Abstract: A safe method of stopping a stolen car without chasing at high speeds, utilizing a bar code implanted between the inner layer and outer layer of a rear safety glass is comprised of steps: 1) scan the barcode, 2) compare the read in barcode with those of the stolen cars stored in the police computer net, 3) trigger one of the three stopping means of this invention. Those three stopping means are: 1) turn off the engine, 2) puncture the rear tires with bullets, and 3) puncture the rear tires by mechanical means.