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Claims  |
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I claim:
1. A personal identification card system, including an identification card
having a plurality of layers bonded together, acoustic data means on one
internal surface of one of said layers for altering the propagation of an
ultrasonic signal through said card in a predetermined, data encoding
pattern, and card scanning means for directing an ultrasonic signal
through said card and detecting the altered signal propagation through
said acoustic data means and said predetermined, data encoding pattern
within said card, wherein said acoustic data means includes an
acoustically encoded holographic image.
2. A personal identification card system, including an identification card
having a plurality of layers bonded together, acoustic data means on one
internal surface of one of said layers for altering the propagation of an
ultrasonic signal through said card in a predetermined, data encoding
pattern, and card scanning means for directing an ultrasonic signal
through said card and detecting the altered signal propagation through
said acoustic data means and said predetermined, data encoding pattern
within said card, wherein said acoustic data means includes digital data
in acoustically encoded form.
3. A personal identification card system, including an identification card
having a plurality of layers bonded together, acoustic data means on one
internal surface of one of said layers for altering the propagation of an
ultrasonic signal through said card in a predetermined, data encoding
pattern, and card scanning means for directing an ultrasonic signal
through said card and detecting the altered signal propagation through
said acoustic data means and said predetermined, data encoding pattern
within said card, wherein said acoustic data means includes analog data in
acoustically encoded form.
4. A personal identification card system, including an identification card
having a plurality of layers bonded together, acoustic data means on one
internal surface of one of said layers for altering the propagation of an
ultrasonic signal through said card in a predetermined, data encoding
pattern, and card scanning means for directing an ultrasonic signal
through said card and detecting the altered signal propagation through
said acoustic data means and said predetermined, data encoding pattern
within said card, wherein said layers are optically opaque to prevent
visualization of said acoustic data means.
5. A personal identification card system, including an identification card
having a plurality of layers bonded together, acoustic data means on one
internal surface of one of said layers for altering the propagation of an
ultraonsic signal through said card in a predetermined, data encoding
pattern, card scanning means for directing an ultrasonic signal through
said card and detecting the altered signal propagation through said
acoustic data means and said predetermined, data encoding pattern within
said card, wherein said card scanning means includes an ultrasonic
transducer for emitting said ultrasonic signal, means for receiving said
ultrasonic signal after said signal passes through said card, said
ultrasonic transducer also comprising said means for receiving said
ultraonsic signal, and further includign means for translating said card
relative to said transducer and said means for receiving to scan said
acoustic data means portion of said card.
6. A personal identification card system, including an identification card
having a plurality of layers bonded together, acoustic data means on one
internal surface of one of said layers for altering the propagation of an
ultrasonic signal through said card in a predetermined, data encoding
pattern, card scanning means for directing an ultrasonic signal through
said card and detecting the altered signal propagation through said
acoustic data means and said predetermined, data encoding pattern within
said card, wherein said card scanning means includes an ultrasonic
transducer for emitting said ultrasonic signal, means for receiving said
ultrasonic signal after said signal passes through said card, further
including liquid acoustic couplant means in which said card, said
transducer, and said means for receiving are all immersed.
7. The system of claim 6, further including beam splitter means for
dividing said ultrasonic signal into an interrogation signal and a
reference signal, and means for directing said interrogation signal
through said card to a surface of said liquid couplant means.
8. The system of claim 7, further including means for directing said
reference signal to intersect said interrogation signal at said surface of
said liuqid couplant means to form a holographic representation thereon.
9. The system of claim 8, further including optical holographic imaging
means for converging said holographic representation at said surface of
said liuqid couplant to a visible hologram.
10. A personal identification card system, including an identification card
having a plurality of layers bonded together, acoustic data means on one
internal surface of one of said layers for altering the propagation of an
ultrasonic signal through said card ina predetermined, data encoding
pattern, card scanning means for directing an ultrasonic signal through
said card and detecting the altered signal propagation through said
acoustic data means and said predetermined, data encoding pattern with in
said card, wherein said card scanning means includes an ultrasonic
transducer for emitting said ultrasonic signal, means for receiving said
ultrasonic signal after said signal passes through said card, wherein said
ultrasonic transducer includes a layer of piezoelectric material therein,
and a plurality of conductors disposed in an array impinging on said
piezoelectric layer and adapted to electrically interact with portions of
said piezoelectric layer to transmit or receive ultrasonic signals.
11. A personal identification card system, including an identificationc ard
having a plurality of layers bonded together, acoustic data means on one
internal surface of one of said layers for altering the propagation of an
ultrasonic signal through said card in a predetermined, data encoding
pattern, card scanning means for directing an ultrasonic signal through
said card and detecting the altered signal propagation through said
acoustic data means and said predetermined, data encoding pattern within
said card, wherein said card scanning emans includes an ultrasonic
transducer for emitting said ultrasonic signal, means for receiving said
ultrasonic signal after said signal passes through said card, further
including dry acoustic coupling means interposed between said ultrasonic
transducer, said card, and said receiving means for impedance-matching the
acoustic signal propagation therethrough. |
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Claims  |
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Description  |
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BACKGROUND OF THE INVENTION
In recent years the phenomenal growth of the use of credit cards, automatic
bank teller machines, identification cards, and the like has alleviated
the problems associated with individuals carrying large amounts of cash
and valuables on their persons. Unfortunately, these newly created card
devices have engendered new problems unique to their existence. Although
credit cards (this term will be used generically herein to encompass all
forms of credit, identification, and machine readable cards) are not as
anonymous and transferable as cash, they are still subject to unauthorized
use due to loss, theft, and forgery. Indeed, in some situations credit
card fraud can be more egregious than loss of cash or valuables, due to
the great amount of wealth which may be called forth and misappropriated
from the criminal misuse of one small plastic card.
In its typical form a credit card comprises a rectangular, pocket-size
piece of laminated plastic which bears the name of the issuing authority
or institution, the name of the individual who is the authorized user, an
identifying number, and perhaps an expiration date. This information is
usually embossed so that the indicia may be transferred to a credit
invoice by direct impression. Most credit cards also include a space for
the authorized person's signature, so that the signature may be compared
with the user's signature at the point of sale or credit. However, this
system obviously provides the opportunity for a dexterous criminal to copy
and forge the signature of the authorized individual. indeed, even when a
photo of the authorized person is provided on the card, forgery of the
entire, including the photo and signature, has frequently been
accomplished by talented criminals.
A more recent innovation has been the inclusion of a magnetic strip on one
surface of the card, the strip being encoded with bearer data such as an
authorization number which is not indicated outwardly on the card. Some
criminals with access to card readers have been able to scan the magnetic
strip of a stolen card to determine the authorization number. More often,
however, the authorized individual writes the number on a card or paper
accompanying the credit card, so that the number is not forgotten. In this
way the criminal may gain access to the authorizing number, and thus to
the credit resources of the individual.
SUMMARY OF THE PRESENT INVENTION
The present invention generally comprises a method and apparatus for
providing a credit card and personal identification card system which
virtually eliminates the unauthorized use of such cards. A salient feature
of the present invention is the provision of a credit card which includes
embedded information or characteristics unique to the authorized
individual but unreadable by any visual means. Moreover, the information
does not appear at all on the exterior of the card, so that the right of
privacy of the authorized individual is not infringed at all. Furthermore,
the embedded information may include personal characteristics which cannot
be forged or reproduced except by the authorized individual.
The apparatus of the personal identification card system of the present
invention includes a card having a plurality of laminar composite layers
of optically opaque, acoustically transparent plastic, resin, metallic
film, or fiber inlaid material. The layers are joined permanently together
by bonding, cladding, or the like, with identification information and
characteristics written on the inner surfaces of the lamina. The
information is not visible from the exterior of the card, and is written
as analog and digital indicia and images adapted to be read by ultrasonic
imaging means. Such information may include the authorized cardholder's
signature, fingerprint, voiceprint, or other personal characteristic which
are virtually impossible to duplicate by other persons. The information
may also include numerical indicia such as authorization codes, social
security number, birthdate, and the like, which are difficult to obtain by
other individuals.
The invention also includes the ultrasonic imaging card reading terminal
for reading the information covertly stored within the lamina of the card
of the present invention. The terminal includes liquid or dry coupling
means for connecting an ultrasonic scanning device to the card. The
scanning device may employ such prior art techniques as pulse-echo two
dimensional B-scan, through-transmission two dimensional B-scan; pulse
echo, three dimensional volumetric C-scan; pulse-echo, three dimensional
tomographic scan in terms of amplitude (acoustic impedance mismatch)
and/or time (acoustic velocity) through-transmission, tomographic
area-amplitude scan liquid surface acoustic holography; and electronic
reference acoustic holography.
The terminal of the present invention is adapted to provide "on the spot",
virtually instantaneous reading of the information in the card, so that
the authenticity of the card bearer may be determined through comparison
of the personal characteristics of the bearer and the record thereof in
the card. In addition, the numerical indicia provides further verification
opportunity, so that unauthorized use of a card of the present invention
is reduced to a minimum level far below any prior art card identification
system.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an exploded perspective view of one embodiment of the
identification card of the present invention.
FIG. 2 is an exploded perspective view of a further embodiment of the
identification card of the present invention.
FIG. 3 is a schematic representation of one embodiment of the ultrasonic
card scanning device of the present invention, using either pulse-echo or
through-transmission measuring and imaging techniques.
FIG. 4 is a side elevation of an ultrasonic card scanning device of the
present invention, using through-transmission ultrasonic measuring and
imaging in conjunction with electronic scanning and dry acoustic coupling.
FIG. 5 is a partially cutaway perspective view of one of the scanning
detectors depicted in FIG. 4.
FIG. 6 is a schematic representation of a real time, ultrasonic scanning,
liquid surface holographic image retrieval system used in conjunction with
the identification card system of the present invention.
FIG. 7 is a block diagram representation of an embodiment of the
identification card scanning terminal of the present invention, employing
electronically referenced, holographic imaging techniques to retrieve
information from the card of the present invention.
FIGS. 8a-8c are schematic views depicting the ultrasonic beam propagation
and detection paths for pulse-echo and through-transmission information
retrieval techniques in the card scanning device of the present invention.
FIGS. 9a-9c are graphic plots of amplitude versus time and phase for the
interrogation beam and the received beam in the various embodiments of the
ultrasonic card scanning device of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention generally comprises a personal identification card
system, and encompasses such items as credit cards, automatic teller
machine access cards, identification cards, driver's license cards, and
the like. A salient feature of the present invention is that the card of
the present invention incorporates information and personal
characteristics unique to the individual who is authorized to use the
card, so that identification of that individual may be made without error.
This information is not displayed overtly on the exterior of the card,
however, so that the privacy of the individual is not comprised, and so
that unauthorized use of the card is made extremely difficult if not
impossible.
With regard to FIG. 1, one embodiment of the identification card of the
present invention includes two layers 11 and 12 adapted to be bonded or
clad together in permanent fashion. At least one confronting surface of
the two layers is provided with identification information 13 written
thereon in digital, analog, or indicial form. Joining of the two layers
renders the information 13 totally unintelligible by visual inspection.
The layers 11 and 12 are formed of plastic or like materials having
excellent ultrasonic energy propagating characteristics and additionally
include substances to render the layers optically opaque to obscure the
data 13. The materials and the data encoding and writing technique are
also selected to prevent retrieval of the data 13 by techniques such as
electromagnetic interrogation, microwave and capacitive dielectric
scanning, radiation scanning by hard .beta., gamma, x-ray, and neutron
imaging methods, and by thermal and infrared techniques. Thus the only
means for reading the data 13 is by use of ultrasonic scanning techniques,
as will be explained in the following description. The data 13 may be
written by engraving, etching, plating, machining, printing of
acoustically functional material, or the like. The exterior of the layer
12 is provided with indicia 14, such as the name of the individual
authorized to use the card. It may be appreciated that the outward
appearance of the card provides absolutely no clue as to the information
or data incorporated within the card.
Another embodiment of the identification card of the present invention,
shown in FIG. 2, includes a pair of outer layers 16 and 18, with a core
layer 17 interposed therebetween. Data 19 is written on at least one
surface of the core layer 17, by means described previously, and the three
layers are bonded or otherwise permanently joined to form the card. A
simple data statement 21, such as the name of the authorized user, maybe
be placed on the exterior surface. As before, the materials and the
encoding and writing techniques are selected so that only ultrasonic
scanning techniques may retrieve the data. The data may be written in a
form that provides an acoustic impedance either higher or lower than the
impedance of the core 17. The phase of a reflected ultrasonic beam
traversing a high to low impedance interface is reversed by 180.degree.,
while the transition from low to high impedance causes no phase change,
and through transmission causes no phase change in either case. Thus, the
phase of the reflected signal may be derived to determine the location and
data content of the acoustic indicia. Alternatively, the indicia which
comprise the data 19 may be formed of a material having a higher or lower
acoustic velocity than the material of the core 17. The ultrasonic signal
passing through the indicia will be temporally displaced with respect to
the signal through the core itself, and this displacement may be used to
determine the information content of the indicia, as will be explained in
the following description.
With reference to FIG. 3, one embodiment of the pulse-echo form of
ultrasonic card data retrieval system of the present invention includes an
ultrasonic transducer transmitter-receiver 22, and an ultrasonic receiver
transducer 26 disposed in coaxial alignment. An identification card 24
containing embedded data 25, as described previously, is inserted between
the components 22 and 26, in a liquid coupling medium 23 which minimizes
impedance mismatch between the transducers and the card material. The
transducer 22 and 26 are mechanically coupled so that they translate in
common laterally along the plane of the card 24 for spatial translation
imaging.
Ultrasonic energy in the form of a high resolution pulse is transmitted
from the transducer 22 through the medium 23 to the card 24. A portion of
the pulse energy is reflected from the card-coupling medium interface,
while the remainder of the pulse is conducted into the card and continues
to propagate to the back surface of the card when no encoded data is
disposed in the pulse path. A second reflection takes place at the back
surface, and returns toward the transducer 22. A small portion of the
pulse energy arrives at the transducer 26. In the event that reflective
data portions in the segment 25 are disposed in the pulse path, a
substantial portion of the pulse will be reflected therefrom, and
virtually no reflection will occur at the back surface of the card.
Electronic gating is employed to separate the reflective data signals from
the card boundary signals, the data signals being subsequently displayed
by the device to yield an image of the embedded data 25. This use of
reflected ultrasonic energy comprises pulse-echo imaging of encoded data.
The signal (or absence thereof) from the transducer 26 may be used to
confirm the presence of the reflective data in the layer 25. The signal
relationships are discussed in the following and depicted in FIGS. 9a-9c.
The use of angle beams to propagate shear wave energy as opposed to
longitudinal wave energy in the card may be used to improve the range
resolution of the device due to the slower velocity of the shear wave in
the card material, resulting in greater temporal separation of the signals
and greater ease in gating and separating the various signals.
A through-transmission embodiment of the ultrasonic card scanning system is
depicted in FIGS. 4 and 5. The system includes a laminated identification
card having embedded data portion 32 and 33, comprising acoustically
reflective portions and controlled acoustic velocity portions,
respectively. A pair of acoustic transducer assemblies 34 and 36 are
disposed in spaced apart, opposed fashion and adapted to receive the card
31 therebetween. Each of the transducers is comprised of a plurality of
stacked layers laminated together, and includes an acoustic coupling layer
37 adapted to impinge one one lateral surface of the card 31. The layer 37
is formed of a material which optimizes the acoustic impedance match
between the card and the transducer itself, so that propagation of
ultrasonic energy into the card is maximized. Adhered directly to the
coupling layer 37 is a conductive layer 38 which is connected to
electrical ground.
Joined to the grounded layer 38 is further layer 39 formed of a
piezoelectric material and adapted to generate acoustic energy. The layer
39 may comprise a piezo electric crystalline material, or plastic film, or
the like, as is known in the prior art. Another layer 41 joined to the
piezo layer 39 is comprised of a large plurality of conductive elements 42
extending laterally and arrayed in closely spaced, adjacent fashion. The
conductive elements 42 are electrically isolated each from the other, and
are individually connectable (addressable) by techniques commonly known in
the prior art. It is significant to note that the conductive elements of
the transducer 34 are arrayed perpendicularly with respect to the
conductive elements of the transducer 36, although the arrays are disposed
in parallel planes.
In the operation of the embodiment of FIGS. 4 and 5, the card 31 is placed
between the transducers 34 and 36, with the coupling layers 37 thereof
impinging on the opposed sides of the card. The conductive elements 42 of
the transmitting transducer are then actuated sequentially, causing
electrical stimulation of the strip of piezo layer 39 directly adjacent to
the conducting element as current flows therefrom to the grounded layer
38. The acoustic pulse emanating from the energized strip is conducted
through the coupling layer to the card, and propagated therethrough to the
opposed receiver transducer.
However, the receiver transducer conductive elements are disposed
orthogonally with respect to the line-configured transmitting area. To
scan the card 31, the same transmitting line element is pulsed repeatedly,
while the receiver transducer the line- configured receiving elements are
actuated sequentially, so that a line of received pulses is swept
laterally across the card. The next transmitting element is then pulsed
repeatedly to form the next line, and the process is repeated to form a
raster scan of the entire card. In the event that reflective data segments
are present in the pulse path, the received signal is diminished by an
amount equal to the reflected energy removed from the transmitted beam in
the zone of the reflective segment. Differing acoustic velocity segments
will temporally displace the received pulse with respect to the time or
reception through the card material itself, and proper receiver gating can
resolve the velocity-coded areas.
Diffraction effects may tend to degrade the received signal, especially in
resolving small area reflective segments. Higher ultrasonic frequencies
reduce diffraction effects for small area reflectors, but cause higher
signal attenuation. Therefore, a trade-off between frequency and
attenuation must be optimized to obtain the best resolution and signal-to
noise factor for the card material and thickness. This is accomplished by
proper choice of pulse width and frequency to provide the optimum spectral
frequency content. The resolution is also a function of the width and
separation of the conductive elements in the receiver and transmitter
transducers. In the preferred embodiment the elements are approximately 12
mils (0.33 mm) wide with a separation of 3 mils (0.13 mm), and the area
resolution is approximately 12 to 15 mils (0.33-0.38 mm).
FIGS. 8a-8c depict the possible ultrasonic signal paths in scanning a card
of the present invention in which the data is embedded using reflective
means or variable acoustic velocity means to alter the signal. FIGS. 9a-9c
graphically depict the time and phase of the signals propagated through
the card of the present invention, using either reflective or variable
acoustic velocity means, and correlate directly with the path depictions
of FIGS. 8a-8c. The components in each figure include the identification
card 71, a liquid or dry coupling medium 72, a transmitting and receiving
transducer 73, and a receiving transducer 74, all labelled with the
appropriate suffix. The beam paths are labelled as T.sub.n for transmitted
pulse, and R.sub.n for reflected pulse, with n equal to the number of the
path segment along the propagation path. FIG. 8a depicts a card portion
containing no embedded data, FIG. 8b depicts acoustic beam propagation
through high or low acoustic impedance (Z.sub.L) reflector encoded data.
FIG. 8c illustrates acoustic beam propagation through encoded data formed
by acoustic velocity elements having higher or lower acoustic velocity
(V.sub.L) than the card material.
The signal T.sub.10 shown in the pulse-echo wavetrain of FIG. 9a represents
the transmitted pulse energy at time zero and is common to all the graphs
of FIG. 9. The signal R.sub.1 is the first reflected signal from the
card-couplant interface, and is also common to all the graphs. Signal
T.sub.1 R.sub.2 R.sub.1 shown in the pulse-echo wavetrain of FIG. 9a is
the first internal card roundtrip reflected signal, and signal T.sub.1
R.sub.2 R.sub.3 R.sub.4 R.sub.1 is the second roundtrip reflected signal.
It is significant that these signals are reversed in phase, by 180.degree.
and 540.degree., respectively, due to the low Z.sub.L of the card-couplant
reflecting interfaces. Signal T.sub.1 T.sub.2 is the first
through-transmission signal to be received by the receiving transducer,
and its phase is the same as the initially transmitted pulse. The second
through-transmission signal is T.sub.1 R.sub.2 R.sub.3 T.sub.2, and its
phase shift of 360.degree. puts it in phase with the initial pulse.
Such interpretation of the signal path relationships and phase and timing
relationships determines the card scanner requirements for signal
analysis, particularly for time gating and phase acceptance. For example,
the presence of a reflective data segment in FIG. 8b attentuates the first
through transmission T.sub.1 T.sub.2, with respect to the absence of data
in FIG. 8a, without temporal shifting of the signal. It is clear that
discrimination of data depends on gating the received signal in the time
space around T.sub.1 T.sub.2, and detecting the differing amplitudes. In
pulse-echo detection, a high Z.sub.L data segment (FIG. 8b) will time
shift and phase shift 180.degree. the first signal received, in comparison
to the no data example of FIG. 8a, and the time gating and phase detecting
requirements are evident. The low Z.sub.L example does not shift the
phase, but the return signal is time shifted closer to the initial pulse,
since the path length is shorter. Thus, a time gate spaced closer to the
initial pulse will discriminate the presence of data segments in the card.
It is apparent that the time shift and phase shift of the
through-transmission and pulse echo signals provide the necessary
information to detect the presence of date embedded within the
identification card of the present invention. The presence of high and low
acoustic velocity reflective and transmissive data elements exhibit
uniquely identifiable characteristics. Correlating the presence or absence
of data elements with a raster-type representation of the card provides a
complete image field of the data within the card. Instrumentation with
such capabilities is well known in the prior art.
A further method for storing information within the card of the present
invention comprises forming a holographic image within the embedded layer
or surface, and scanning the image ultrasonically in the card reading
terminal to retrieve the image. As in the previous embodiments, the
holographic image elements may be written within the card by engraving,
printing, impressing, etc., and the image is scanned as depicted
schematically in FIG. 6. The holographic scanning system in the card
reading terminal includes an ultrasonic transmitting transducer 46
emitting a pseudocontinuous wave beam along a path directed toward the
identification card 48. A beam splitter 47 interposed in the beam path
divided the ultrasonic beam into two separate beams, one of the beams 50
continuing along the original path to pass through the card 48. The other,
reference beam 50' is directed to a reflector 49, and the reflected beam
is directed to converge with the path of the beam 50 after it passes
through the card 48.
The elements 46-49 are all immersed in a liquid coupling medium 51 which
enhances ultrasonic beam propagation. Furthermore, the beams 50 and 50'
are aligned to intersect at a portion 52 of the surface of the liquid
coupling medium, forming an interference pattern which contains the
holographic information embedded within the card 48. The radiation
pressure of the interfering beams physically distorts the liquid surface.
A conventional coherent light laser holographic imaging system 53 then
scans the surface portion 52 to form a visible holographic image of the
card-contained image. The operator of the identification card scanning
device may view the hologram for purposes of identification and
comparison; however, additional instrumentation is required to analyze and
evaluate any additional encoded digital or analog information embedded in
the card, as described previously.
With reference to FIG. 7, a further embodiment of the present invention is
adapted to read both digital and analog data as well as holographic image
data from a card 56 of the present invention. It includes a ultrasonic
card scanning device 57, acoustically dry coupled to the card 56, as
described previously, which is connected to an ultrasonic pulse generator
and sequencer 58. The output of the card scanner 57 is fed through a
receiver amplifier and pulse sequencer 59 to a temporal gating device 61.
The temporal gating device is controllable to select the depth of the
imaging plane for the hologram or C-scan imaged data, and also to time
gate and phase and amplitude detect the B-scan data, according to the mode
desired by the operator. A control panel 64 provides operator control and
selectivity, and a microprocessor 66 operates the system according the the
operator commands entered through the control panel.
The gated signal information passes to a point source holographic data
generator 63, where it is combined with a reference signal from a
reference signal generator 62. The output of the data generator is then
conducted to a video output device 67, where the embedded card data is
displayed for easy visualization. Such data may include the authorized
card owner's name, authorization number, social security number or the
like, a graph of the spectral energy of the voice of the authorized
person, or other personal characteristics which cannot be forged. The card
reader terminal of FIG. 7 may be connected to a central data processing
network for verification of the readout information, so that forgery or
alteration of a card is made virtually impossible.
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Description  |
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