A torque control system for an engine performance test machine for internal combustion engines comprises an oscillating type electric dynamometer including a rotor and an oscillating member being oscillatably supported around said rotor and a connecting device for interconnecting the rotor shaft and the rotating member of the engine. The torque control system also includes a load cell for monitoring oscillating torque of the oscillating member, means for generating a first torque occurring at the rotor, means for generating a second torque occurring at the rotating member. The torque control system also includes means for generating a detection signal representative of the sum of said oscillating torque, and the first and second torques, and a controller for adjusting the torque generated by the engine in response to the detection signal.

1. Field of the Invention
The present invention relates to a torque control system which is optimally adapted for use in an engine performance test machine including an oscillating type electric dynamometer so as to make an engine performance test for internal combustion engines under a predetermined operating mode wherein the engine revolution and the output torque of the engine are changed in accordance with a predetermined test pattern.
2. Description of the Prior Art
In an engine performance test machine for internal combustion engines, an oscillating type electric dynamometer is traditionally used. The rotor shaft of the electric dynamometer is connected through a coupling device to the rotating member of the engine, which includes a crankshaft and a flywheel. A buffering device, such as a shaft having a rubber damper is usually provided between the rotating member and the coupling device so as to prevent damage in the coupling device due to torque fluctuations generated by the engine. For the same reason, a clutch plate having torsional characteristics as shown in FIG. 3 is often provided between the rotating member of the engine and the coupling device. As is generally known, the torque fluctuation of diesel engines is greater than gasoline engines. For this reason, in engine performance tests for diesel engines, both the buffering device and the clutch plate are generally used. When engine performance, such as output torque, is measured under a particularly steady operating state of the engine by the oscillating type electric dynamometer, the mean engine torque is preponderantly detected and measured by the dynamometer. In the above mentioned test, the component of engine torque fluctuation is not important and is not detected. The component of engine torque fluctuation is actually absorbed as an oscillating energy relative to the oscillating member which has a relatively large axial moment of inertia and which is disposed around the rotor of the dynamometer such that the oscillating member is oscillatably supported through bearings in a conventional method.
Recently, there have been proposed and developed various engine performance test machines for internal combustion engines in which the engine performance tests are made of transient operating states as well as steady operating states, that is the test is made in a predetermined complicated test mode combining various transient and steady operating states of the engine. Therefore, a torquemeter which is disposed between the rotating member of the engine and the rotor shaft of the dynamometer, is widely used in such a manner as to continuously detect engine torque measured at a drive shaft of the engine. Specifically, in emission tests for heavy-duty vehicles based on the regulations regarding exhaust gas in the U.S., pollutants in the exhaust gas are measured under a condition wherein engine revolution and output torque are controlled in accordance with a predetermined operating mode of the engine. In such a case, it is desirable that the engine torque is continuously detectable by the torquemeter and the engine revolutions are continuously detected by the pickup serving as a pulse generator for pulse signals representative of an engine revolution. Thus, the engine revolutions and the engine torque may be precisely measured and/or controlled.
One such conventional engine performance test machine is shown in FIG. 1. Referring now to FIG. 1, a rotating member of an internal combustion engine 1 is connected through a connecting shaft, such as a drive shaft 2a land a coupling 3b to an input shaft of a torquemeter 3. The output shaft of the torquemeter 3 is connected through a coupling 2b to the rotor shaft of an oscillating type electric dynamometer 2. The torquemeter 3 outputs a signal representative of shaft torsion being essentially proportional to the output torque generated by the engine 1. The torsion signal from the torquemeter 3 is processed into the engine torque signal by a transducer 30. Thereafter, the engine torque signal is output from the transducer 30 to an accelerator controller 17, and is compared with a preset engine torque command signal representative of a preset engine torque. After comparing the preset torque command signal and the detected engine torque signal, the accelerator controller 17 outputs a signal representative of the difference between the two torque signals to the accelerator actuator 18. The accelerator actuator 18 adjusts the angular position of an accelerator 1a. Thus, the output torque of the engine 1 may be set to a predetermined value.
On the other hand, the engine revolution is detected by a pickup 7 which is disposed in the vicinity of one end of the rotor shaft of the dynamometer 2. The pickup 7 outputs a pulse signal representative of the revolution of the rotor shaft to a frequency/voltage transducer 8, whereby the pulse signal from the pickup 7 is processed into an analog signal representative of an engine revolution. Thereafter, the engine revolution signal is output from the frequency/voltage transducer 8 to a dynamometer controller 9, and is compared with a preset engine revolution command signal representative of a preset engine revolution. After comparing the preset revolution command signal and the detected engine revolution signal, the dynamometer controller 9 outputs a signal representative of the difference between the two revolution signals to the dynamometer 2. Thus, the load relative to the rotor of the dynamometer 2 is adjusted and as a result the revolution of the rotor is adjusted. That is, the engine revolution is set to a predetermined engine revolution. The above mentioned preset engine torque and engine revolution command signals are output via a preset value setting circuit (not shown) to the two controllers 17 and 9, respectively.
However, in the above described conventional engine performance test machine shown in FIG. 1, a torsional vibration system shown in FIG. 2 is constructed. Referring now to FIG. 2, a rotating engine member having ah axial moment of inertia I.sub.E is connected through a clutch plate C, a drive shaft P including a rubber damper, a coupling Cl, a torquemeter TM, and a coupling C2 to a rotor of the dy-amometer having an axial moment of inertia I.sub.D, in that order. Therefore, in the conventional engine performance test machine constructed with the above mentioned torsional vibration system, torque fluctuations occur due to the torsional vibration system itself as well as torque fluctuation generated by the engine.
In a four-cycle diesel engine four strokes are utilized, namely an intake stroke, a compression stroke, an explosion stroke, and an exhaust stroke, fluctuation in torque generated by the engine occurs due to the compression stroke wherein the output torque is decreased and the explosion stroke wherein the output torque is increased. For example, in a conventional four cylinder four cycle diesel engine, the frequency of the torque fluctuation is 20 Hz or more, when the engine is running at an idling speed, for example 600 r.p.m. In a conventional six cylinder four cycle diesel engine, the frequency of the torque fluctuation is 22.5 Hz or more, when the engine is running at idling speed, for example 450 r.p.m. Preferably. the response frequency applicable for the engine torque control is 2 Hz or less. Therefore, such a relatively high frequency torque fluctuation generated by the engine may be filtered by means of a low-pass filter. Thus, engine torque control can be executed by engine torque detected through the torquemeter, not including the component of torque fluctuation occurring in the engine.
While, torque fluctuation due to the torsional vibration system occurs depending upon the torsional rigidity of the connecting device including connecting elements, such as a clutch plate, couplings, a drive shaft. The frequency of the torque fluctuation corresponds to the torsional vibration frequency of the torsional vibration system shown in FIG. 2. If the torsional rigidity of the connecting device is set to a relatively high value, there is a possibility that the torsional vibration frequency of the torsional vibration system will become equal to the frequency of the torque fluctuation occurring in the engine. When the two frequencies become equal to each other, resonance relative to the connecting device occurs through torque fluctuation of the engine, thereby resulting in damage to the connecting device. For this reason, the torsional rigidity of the connecting device is generally set to a relatively low value. Traditionally, the connecting device is comprised of the clutch plate of a manual transmission including a plurality of torsion springs and/or a drive shaft including a rubber damper. In this manner, the frequency of the torsional vibration system is set to a relatively low frequency, for example 5 Hz or less. Actually, the frequency of the torsional vibration system changes depending on the torsional characteristics of the clutch plate shown in FIG. 3. As clearly seen in FIG. 3, as the absolute value of the engine torque is increased, the torsional angle of the clutch plate is increased, that is the torsional rigidity of the clutch plate is increased. Conversely, as the absolute value of the engine torque is decreased, the torsional rigidity of the clutch plate is decreased.
As set forth above, the torsional vibration frequency of the torsional vibration system changes within a range of relatively low frequencies, for example 5 Hz or less. Since the torsional vibration frequency range of the torsional vibration system is in close proximity to the response frequency, for example 2 Hz, required for the torque control, the component of torque fluctuation generated due to the torsional vibration system cannot be filtered by the low-pass filter. As a result, the above mentioned component of the torque fluctuation generated by the torsional vibration system deteriorates the torque control accuracy. That is, since the detected engine torque signal input into the accelerator controller 17 also includes the component of the torque fluctuation due to the torsional vibration system, the accelerator 18 can be controlled by the controller 17 in response to the torque fluctuation due to the torsional vibration system as well as the actual output torque fluctuation. To avoid the deterioration in the torque control, the response frequency may be lowered to 0.5 Hz or less. However, such an extremely low response frequency results in a low responsiveness of the accelerator controller for torque control.
To obtain high accuracy and high responsiveness of torque control, there has been proposed an engine performance test machine in which the engine torque is controlled by a learning control method. One such engine performance test machine has been disclosed in the MEIDEN REVIEW No. 178 (Pages 30-33) issued by Kabushiki Kaisha Meidensha. However, an expensive computer must be used for the learning control.

Torque control system for engine performance test machine for internal combustion engines


A mechanism is provided for collecting one or more performance metrics. A plurality of source code instructions is provided. The source code instructions include a plurality of macro calls. Each of the plurality of macro calls includes a plurality of predetermined parameters. A plurality of object code instructions corresponding to the plurality of source code instructions is executed. In response to receiving a signal identifying at least one of the plurality of macro calls contained in the source code instructions and identifying a desired level of granularity, performance metrics are collected using the identified macro call in accordance with the desired level of granularity.

The disclosure relates generally to performance monitoring, and more specifically to dynamic performance data collection in large computer servers.
An IBM System z® computer is a product line of large computer servers or mainframes based on the z/Architecture® provided by International Business Machines Corporation (IBM®) of Armonk, N.Y. IBM System z® computers can utilize a derivative of the Multiple Virtual Storage (MVS) operating system, which is a robust mainframe operating system utilized by many generations of IBM® mainframe computers. Derivatives of the MVS™ operating system can include the OS/390® operating system and IBM z/OS® (IBM System z®, z/Architecture®, IBM®, OS/390® and IBM z/OS® are registered trademarks of International Business Machines Corporation, located in Armonk, N.Y.).
IBM System z® computers typically run mainframe applications based on the programming languages designed for these environments, such as COBOL, PL/I and Assembler. These mainframe applications typically handle high volumes of data and/or high transaction rates within complex systems and user environments. Therefore, these applications are usually critical to the business in which the IBM System z® computer is installed.
Both execution time and cost are factors that must be considered when running mainframe applications. For example, execution time may be critical with respect to the performance of batch systems and with respect to particular response times required by certain applications (such as web-based or other on-line systems). However, increasing data volumes due to higher business complexity can cause batch process to exceed desired time limits and can increase the response times of critical web-based applications to unacceptable levels. Furthermore, mainframe systems are often associated with high operating costs since many businesses pay for mainframes on a usage basis (for example, license costs are often coupled to the number of MIPS ("Million Instructions Per Second") in a mainframe installation) and also may pay fixed license costs for mainframe software. Given the increasing pressure to reduce IT spending, these costs have become a major problem to many businesses using mainframe computers.
Given the increasing execution time requirements and cost pressures, businesses are forced to evaluate their current mainframe installations. One option available to such businesses is to upgrade the computer hardware. However, this creates additional fixed costs and is typically only a good choice if money is not a primary decision-driving factor or if the company needs to react immediately. Another option is to optimize and tune the system environment and the applications running in the environment. Utilities have been developed to gather specific performance related data in a mainframe environment, but to date these programs have been largely focused on measuring performance at a mainframe job level. These utilities do not provide a flexible way to capture data at more granular levels, such as, for example, a single line of assembler instruction.

Dynamic performance data collection in large computer servers


Methods, systems, and devices for techniques for adjusting current based on operating parameters are described. An apparatus may include an amplifier, a feedback component, and first and second current generators. The amplifier may include an input for receiving a first voltage and an output for outputting a second voltage. The first current generator may be coupled with the output of the amplifier and generate a first current based at least in part on the second voltage. The feedback component may be coupled with the first current generator to modify the first current based at least in part on an operating temperature associated with a memory device. The first current may be proportional to the operating temperature. The second current generator may be coupled with the first current generator to generate a second current based at least in part on the first current modified by the feedback component.

The following relates generally to one or more memory systems and more specifically to techniques for adjusting current based on operating parameters.
Memory devices are widely used to store information in various electronic devices such as computers, wireless communication devices, cameras, digital displays, and the like. Information is stored by programing memory cells within a memory device to various states. To access the stored information, a component may read, or sense, at least one stored state in the memory device. To store information, a component may write, or program, the state in the memory device.
Various types of memory devices and memory cells exist, including magnetic hard disks, random access memory (RAM), read-only memory (ROM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, phase change memory (PCM), self-selecting memory, chalcogenide memory technologies, and others. Memory cells may be volatile or non-volatile. Non-volatile memory, e.g., FeRAM, may maintain their stored logic state for extended periods of time even in the absence of an external power source. Volatile memory devices, e.g., DRAM, may lose their stored state when disconnected from an external power source.

Techniques for adjusting current based on operating parameters


A balloon pump includes a cylinder having an outlet end and a piston adapted to reciprocate within the cylinder. One-way outlet and inlet valves are associated with the pump for allowing air to exit the cylinder outlet end only when the piston moves toward the outlet end and enter the cylinder only when the piston reciprocates away from the cylinder outlet end. An elongated piston drive member or base is connected at one end to the piston with the other end extending out of the cylinder at the end opposite the cylinder outlet end. A biasing arrangement acts between the cylinder and the piston to bias the piston away from the outlet end of the cylinder. With the pump positioned vertically and supported on the elongated piston drive member, the biasing arrangement raises the cylinder to perform a return stroke so that the pump may be operated simply by pushing down on the cylinder.

This invention relates to pumps for inflating balloons and particularly to a balloon pump designed for use by performers who make balloon figures and articles.
Magicians and other performers often use balloons in their acts to create balloon articles and figures. Usually the performer works alone and must inflate the balloons himself during the show. Although a balloon can be inflated by exhalation, this method prevents the performer from speaking and thus interrupts the performance. Also blowing up balloons in this manner is exhausting. Therefore, hand and motor operated pumps and compressed gas cylinders have also been used for inflating balloons during a performance. Motor driven pumps, however, are too noisy and interfere with the performance, while compressed gas cylinders are too bulky and expensive, particularly for street performers. Therefore, hand operated pumps are most popular with performers.
U.S. Pat. No. D. 220,840 shows one ornamental design for a pump suitable for inflating balloons. This design patent discloses a piston and cylinder type pump with a handle and rod for driving the pump piston and a handle on an outlet end of a cylinder. This pump, however, requires two hands to operate and is thus cumbersome to use in a performance.
U.S. Pat. No. D. 322,471 to the current inventor shows a balloon pump designed specifically for use by performers. This pump includes an elongated piston connected to a base so as to stand upright. A cylinder fits over the piston and is adapted to be moved up and down over the stationary piston by the performer to produce the pump stroke. Although the pump shown in this design patent is lightweight and easily transportable and leaves the performer free to speak while inflating balloons, it still requires two hands to operate. That is, the cylinder must be lifted up by the ring at the top of the cylinder with two hands and then pushed down with one hand to inflate the balloon. Also, the pump shown in the '471 design patent has a fixed height and is uncomfortable for performers above and below a certain height range.


A method of reducing the effect of systematic and/or random noise during determination of dependent variable values, (eg. pseudo “n” and “k” and/or ellipsometric PSI and DELTA or mathematical equivalent vs. wavelength or angle of incidence), involving selecting a mathematical function and an independent variable subset range combination so that a square error best fit with total summed square error over the independent variable subset range being minimized, zero or within an acceptable range near zero, are achieved.

It is known to cause electromagnetic radiation to interact with a sample to obtain data which determines Ellipsometric Parameters, as a function of wavelength and/or angle-of-incidence, and then to perform mathematical regression of a proposed mathematical model of said sample onto values for ellipsometric PSI and DELTA to obtain values of, for instance, thickness and optical constants, where said ellipsometric PSI and DELTA are identified by:ρ=rp/rs=Tan(Ψ)exp(iΔ)
In most cases the regression procedure is successful in providing useful information without the need to pre-condition data to reduce the effects of noise therein. In some cases, however, where it is desired to determine such as a pseudo-"n" and/or pseudo-"k" value of a sample at a specific wavelength, the presence of noise can be a significant source of uncertainty. (Note, pseudo-"n" and pseudo-"k" refer to "n" and "K" for a sample investigated as a monolithic whole, without taking into account specific structure). The disclosed invention provides an approach to overcoming such data analysis difficulty without the need to develop an accurate mathematical model for a sample structure.
A Search for relevant patents, provided a patent to Johs et al., U.S. Pat. No. 5,872,630, from which the present Application is derived as a CIP via intervening CIP Applications. Said 630 patent primarily describes a spectroscopic rotating compensator material system investigation system. Amongst other disclosure said 630 patent describes a Mathematical Regression based Calibration procedure which makes possible the use of essentially any compensator regardless of non-achromatic characteristics. And specifically, parameterization of variables was disclosed as an approach to optimizing use of information available in a data set. The basic concept of the presently Claimed approach to minimizing the effects of noise in data, in the context of data obtained from the practice of ellipsometry, was established and disclosed in said 630 patent which was Filed Aug. 15, 1997.
Additional demonstrative patents which disclose use of a spectroscopic range of wavelengths were also identified as follows.
A patent to Johs, from which the 630 patent was Continued-in Part, is No. 5,666,201, filed Sep. 20, 1995. The focus in said 201 patent comprises a detector arrangement in which multiple orders of a dispersed beam of electromagnetic radiation are intercepted by multiple detector systems.
U.S. Pat. No. 5,706,212, Issued Jan. 6, 1998, and Filed Mar. 20, 1996 for an Infrared Ellipsometer System Regression based Calibration Procedure. Said 212 patent describes use of an Substantially Achromatic Rotating Compensator and application of Mathematical Regression in a Calibration procedure which evaluates calibration parameters in both rotating and stationary components. The 212 patent describes that 2ωMEGA and 4ωOMEGA associated terms are generated by a detector of a signal which passes through a compensator caused to rotate at a rate of OMEGA. Said 630 patent was Continued-in-Part therefrom, as is the present application via an intervening patent application.
A patent to Chen et al., U.S. Pat. No. 5,581,350 is identified as it describes the application of regression in calibration of ellipsometer systems similar to that described in a paper by Johs in 1993.
Other patents are identified as generally describing ellipsometry systems which contain means which can generate data containing systematic or random noise, to which the disclosed invention can be applied.
Patents to Aspnes et al. are Nos. 6,320,657 B1, 6,134,012, 5,973,787 and 5,877,859. These patents describe a Broadband Spectroscopic Rotating Compensator Ellipsometer System wherein the Utility is found in the use of a "substantially Non-Achromatic" compensator and selecting a Wavelength Range and Compensator so that "an effective phase retardation value is induced covering at least from 90 degrees to 180 degrees", (012 patent), over a range of wavelengths of at least 200-800 nm. The 787 and 859 recite that at least one wavelength in said wavelength Range has a retardation imposed of between 135 and 225 Degrees, and another wavelength in the wavelength Range has a retardation imposed which is outside that retardation Range.
A recently published PCT Application is No. WO 01/90687 A2, which is based on U.S. application Ser. No. 09/575,295 filed May 3, 2001. This application was filed by Thermawave Inc. and specifically describes separate use of a 2ω and a 4ω term to provide insight to sample thickness and temperature.
Two patents which identify systems which utilize Polychromatic light in investigation of material systems, U.S. Pat. Nos. 5,596,406 and 4,668,086 to Rosencwaig et al. and Redner, respectively, were also identified.
Also identified is a patent to Woollam et al, U.S. Pat. No. 5,373,359 as it describes a Rotating Analyzer Ellipsometer System which utilizes white light. Patents continued from the 359 Woollam et al. U.S. Pat. Nos. 5,504,582 to Johs et al. and 5,521,706 to Green et al. Said 582 Johs et al. and 706 Green et al. patents describe use of polychromatic light in a Rotating Analyzer Ellipsometer System.
As the disclosed invention contemplates use of focused and non-focused beams of electromagnetic radiation, patents which describe means for focusing in ellipsometer systems were also identified.
A PCT Patent Application, No. WO 01/086257 is also known and is disclosed as it describes a combination of an aperture and lens to define a spot on a sample.
A patent to Lacey et al., U.S. Pat. No. 5,793,480 is disclosed as it describes a field stop and lens combination in an ellipsometer prior to a sample.
A patent to Spanier et al., U.S. Pat. No. 5,166,752 is disclosed as it describes an ellipsometer with lenses and apertures before and after a sample.
Regarding Articles, an article by Johs, titled "Regression Calibration Method For Rotating Element Ellipsometers", which appeared in Thin Film Solids, Vol. 234 in 1993 is also identified as it predates the Chen et al. patent and describes an essentially similar approach to ellipsometer calibration.
A paper by de Nijs et al., titled "Systematic and Random Errors in Rotating-Analyzer Ellipsometry", Optical Society of America, Vol. 5, No. 6 (1988), which identifies two types of errors, (ie. random and systematic).
A book by Azzam and Bashara titled "Ellipsometry and Polarized light" North-Holland, 1977 is disclosed and incorporated herein by reference for general theory.
As well, identified for authority regarding regression, is a book titled Numerical Recipes in "C", 1988, Cambridge University Press.
A need exists for a method of evaluating dependent variables which can be represented as a function of an independent variable in a mathematical function, based upon data which contains noise.

Method of reducing the effect of noise in determining the value of a dependent variable


A hollow wire for enhancing the wires used in a Liquid Crystal Display includes hollow portions so as to increase the cross sectional area and reduce the resistance. An isolation layer with a low dielectric constant is filled in the hollow portions so as to reduce the clecti-ic capacities and maintain the operation efficiency. The isolation layer can be filled in the perpendicularly crossing area between the information lines and gate matrixes to reduce the electric capacities and maintain the operation efficiency. A method for making the hollow wire is also disclosed.

A higher standard and quality is requested for audio and video equipment due to rapid progress of multiple media. Conventional, monitors made of a Cathode Ray Tube (CRT) are not desirable due to requests for thin, compact and durable designs. Plasma Display Panels (PDP), Liquid Crystal Displays (LCD) or Field Emitting Displays (FED) gradually replace the Cathode Ray Tube (CRT) in the market.
The cross sectional area of the metal wires and the correspondent gaps between them in the Liquid Crystal Displays (LCD) has to be narrowed due to the increase of pixels. However, the series resistance of the wires and the parasitic capacitance between the wires are increased when the cross sections and the gaps are narrowed, and the interruption of series capacitance between wires is more seriously concerned.
A multi-layer of wire having more cross sectional area is used to reduce resistance, such as disclosed in Taiwan Patent No. 533325. According to the Skin Effect, the electric charges move along the surface of the conductive objects so that the depth of the conductive objects is increased so as to maintain the narrow gaps between the wires. This becomes a multi-layer structure deemed to be a material-consuming design. A thick wire perpendicularly and alternatively located between the information line and gate matrixes causes protrusion on the surface and is difficult to be manufactured. It is also possible to reduce the operation efficiency of the LCDs because of the cross-talk noise due to the distance between the wires being too close.
The conventional way of arrangement of wires of LCDs results in high resistance, lower operation efficiency and interruption of series capacitance, and these affect the quality of the LCDs. This invention overcomes the shortcomings.

Hollow wire and method for making the same


A digital watermark embedding device has an input section which inputs pixel value data of an image which is a target for embedding of watermark information, an embedded position selection section which determines a position in frequency domain into which the watermark information is to be embedded, irrespectively of a frequency component value, a frequency component value variation decision section which determines a variation of a frequency component value at each embedded position determined by the embedded position selection section, a pixel value variation calculation section which calculates a variation of a pixel value at each point in pixel value domain of the image based on the embedded position in frequency domain determined by the embedded position selection section and on the variation of a frequency component value determined by the frequency component value variation decision section, a pixel value conversion section which embeds watermark information by changing corresponding pixel value data of the image in accordance with the variation of a pixel value at each point in pixel value domain calculated by the pixel value variation calculation section, and an output section which outputs pixel value data of the image into which watermark information has been embedded.

The present invention relates to a digital watermark embedding device and a digital watermark detection device suited to protect a copyright and to control use of data on digital literary properties represented by images and the like by embedding into the data, information (to be referred to as xe2x80x98watermark informationxe2x80x99 hereinafter), such as discrimination information on copyright owners and users of the data, information on the right of the copyright owners, conditions for using the data and confidential information necessary to use the data, in a state in which the watermark information is not easily perceived and then by detecting corresponding watermark information from data into which the watermark information is embedded at need.
In recent years, there is a growing interest in the copyright of digital literary properties such as an image (a static image, a dynamic image), voice data, music data, design data, CG (computer graphic) data and text data. As one of techniques for protecting the digital literary properties, there is known a digital watermark technique.
The digital watermark technique is mainly aimed to protect the copyright of the data and control use thereof by embedding, i.e., concealingly inputting into a digital literary property, watermark information (xe2x80x98WMxe2x80x99 information) such as discrimination information on the copyright owner and users of the data, information on the right of the copyright owner, conditions for using the data and confidential information necessary to use the data, in a state in which the watermark information cannot be easily perceived.
For the purpose of this type, the digital watermark technique is required to satisfy, in particular, the following characteristics:
(1) Robustness Characteristics
Watermark information is difficult to remove from a literary property and to lose even by various data operations (filtering process, data compression/expansion, D/A conversion, A/D conversion and the like). If data is intentionally manipulated to remove the watermark information, data quality greatly deteriorates.
(2) Perceptual Invisibility Characteristics
The literary property into which watermark information is embedded is perceived similarly as the original literary property.
The digital watermark technique is also required to have embedding efficiency for efficiently embedding watermark information, detection efficiency for efficiently detecting watermark information and the like.
Now, as a typical method of embedding watermark information into, for example, image data by means of the digital watermark technique, there is known a method of converting image data into frequency domains and then embedding watermark information to a specific frequency component.
FIG. 1 is a block diagram showing the constitution of a conventional digital watermark embedding device 200 for embedding watermark information into the image data.
In the device 200, orthogonal transform, such as DFT (discrete Fourier transform), DCT (discrete cosine transform), wavelet transform or Hadamard transform, is conducted to image data in pixel value domain which is a target for embedding of watermark information, by an orthogonal transform section 201 and frequency component value data forming image data in frequency domain is obtained.
Next, watermark (WM) information is embedded into a specific frequency component in the image data in frequency domain in the form of noise having a peak by a digital watermark embedding section 202. The watermark information embedding is conducted in the digital watermark embedding section 202 as follows.
First, based on the frequency component data forming the image data in frequency domain, an embedding frequency component selection section 202a selects a frequency component suited for embedding of watermark information, e.g., a frequency component having a peak in case of embedding the above-stated watermark information as noise. The frequency component variation decision section 202b determines the variation of this frequency component value. The frequency component change section 202c changes the frequency component value forming the image data in frequency domain by a variation determined by the frequency component variation decision section 202b and thereby generates frequency component value data on the image into which the watermark information has been embedded.
Next, inverse transform of the orthogonal transform which has been conducted by the orthogonal transform section 201, is conducted to the image data in frequency domain, into which watermark information has been embedded by the digital watermark embedding section 202, by a reverse-orthogonal transform section 203, to thereby obtain image data in pixel value domain into which watermark information has been embedded.
Thus, the watermark information embedded by the digital watermark device 200 shown in FIG. 1 is embedded into the image data in pixel value domain in a state in which the watermark information is dispersed to the entire image and, therefore, robust against various operations. In addition, if the frequency component into which watermark information is embedded is the frequency component of an intermediate frequency or higher, the watermark information is not lost even by a low frequency pass filter which causes the loss of the LSB information of the image data.
With the constitution shown in FIG. 1, since it is necessary to perform orthogonal transformation twice by means of orthogonal transform, heavy load processing is required. Normally, therefore, an image is first divided into a plurality of blocks. For example, it is assumed that the number of pixels of a certain image in horizontal direction and vertical direction are W and H, respectively. The image is divided into a plurality of rectangular blocks each of which includes w and h pixels in horizontal and vertical directions, respectively. While a pixel positioned on upper-left end point in the image is set as an origin, the number of pixels is counted. If a pixel is in the x-th row and the y-th column, the position of the pixel is expressed as (x, y). If a certain pixel satisfies the following relationships: ixc3x97wxe2x89xa6x less than (i+1)xc3x97w and hxc3x97hxe2x89xa6y less than (j+i)xc3x97h, then it belongs to a block positioned in the i-th row in horizontal direction and the j-th column in vertical direction. All of or part of the blocks obtained by dividing the image are subjected to orthogonal transformation, respectively and watermark information is embedded into the blocks.
If orthogonal transform is used to embed watermark information, the quantity of embedding operation is the order of the square of a processed block size. As the block size is larger, the operation quantity considerably increases. Due to this, dedicated hardware is needed if watermark information is embedded into, for example, a dynamic image.
FIG. 2 is a block diagram showing the constitution of a conventional digital watermark detection device 210 for detecting corresponding watermark information from the image data into which watermark information has been embedded by the digital watermark embedding device 200 shown in FIG. 1.
In the device 201, image data in frequency domain is converted to frequency component value data forming image data in frequency domain by orthogonally transforming the image data in pixel value domain into which watermark information has been embedded by an orthogonal transform section 211. Next, a digital watermark detection section 212 detects watermark information having a peak in a specific frequency component from the frequency component value data.
To embed watermark information into target data so that the watermark information is not likely to be lost by various operations, there is proposed a method for spreading and embedding watermark information into a wide range of data by the spread spectrum technique.
FIG. 3 is a block diagram showing the constitution of a conventional digital watermark embedding device 220 for embedding image data while using spread spectrum of PN (pseudo-random number) sequence.
In the device 220, a pixel value at each point in pixel value domain of an image which is a target for embedding of watermark information, is subjected to direct spread spectrum (SS) technique, i.e., the pixel value is multiplied by the pseudo-random number of {xe2x88x921, 1} referred to as PN sequence generated by a PN sequence generation section 220F, by a spread spectrum section 220A. Then, orthogonal transform, such as DCT transform, is conducted to the pixel value at each point in pixel value domain, to which the spread spectrum is conducted, by an orthogonal transformation section 220B, thereby obtaining frequency component value data forming the spread spectrum image data in frequency domain.
Next, a digital watermark embedding section 220C embeds watermark information in the form of noise having a peak in a specific frequency component in the spread spectrum image data in frequency domain. Then, inverse transform of the orthogonal transform previously conducted by the orthogonal transform section 220B is conducted to the spread spectrum image data in frequency domain into which the watermark information has been embedded, by a reverse-orthogonal transformation section 220D, thereby obtaining spread spectrum image data in pixel value domain into which the watermark information has been embedded. Thereafter, inverse spectrum spreading of the spread spectrum previously conducted by the spread spectrum section 220A is conducted to the spread spectrum image data in pixel value domain into which the watermark information has been embedded, by an inverse spectrum spreading section 220E, thereby obtaining image data in pixel value domain into which the watermark information has been embedded.
As stated above, according to the method for conducting spread spectrum using PN sequence and orthogonal transform and then embedding watermark information into target data, the frequency component into which watermark information is embedded may not be necessarily an intermediate frequency component since spread spectrum using PN sequence is conducted. If watermark information is embedded in the form of a peak, inverse spectrum spreading has an effect of thinly dispersing the watermark information into a wide range of frequency components.
The watermark information embedding as stated above may be possibly effective against data operation by A/D (analog/digital) conversion, D/A (digital/analog) conversion and data compression and expansion, as well. However, since A/D conversion, D/A conversion and data compression and expansion have a great effect on image data, watermark information embedding is desirably conducted by spreading the information into as wide a range as possible.
FIG. 4 is a block diagram showing the constitution of a conventional digital watermark detection section 230 for detecting corresponding watermark information from the image data into which watermark information has been embedded by the digital watermark embedding device 220 shown in FIG. 3.
In the device 230, spread spectrum is conducted to the image data in pixel value domain, into which watermark information has been embedded, by a spread spectrum section 231, using the PN sequence generated by a PN sequence generation section 234. Then, orthogonal transform, such as DCT transform, is conducted to a pixel value at each point in pixel value domain to which the spread spectrum has been conducted, by an orthogonal transformation section 232, and frequency component data forming spread spectrum image data in frequency domain is thereby obtained. Thereafter, watermark information having a peak in a specific frequency component is detected from the obtained frequency component value data by a digital watermark detection section 233.
Further, a technique for embedding watermark information by a patchwork method has been conventionally proposed. FIG. 5 shows the block diagram of a conventional digital watermark embedding device employing this technique.
In a digital watermark embedding device 240 shown in FIG. 5, two pixels are first selected as a pair  less than (ax, ay), (bx, by) greater than  from the pixel value data on an image into which is a target for embedding of watermark information, by a pixel value pair generation section 241.
Next, if 1 is embedded as watermark information, for example, the pixel value a of the first component in the pair, i.e., the first component (ax, ay) is incremented by 1 by the first component change section 242, whereas the pixel value b of the second component in the pair, i.e., the second component (bx, by) is decremented by 1 by the second component change section 243. If 0 is embedded as watermark information, by contrast, the pixel value of the first component is decremented by 1 by the first component change section 242, whereas the pixel value of the second component is incremented by 1 by the second component change section 243. The above-stated operation is conducted to a plurality of pairs selected at random so as not to overlap each other by the pixel value pair generation section 241.
As a result, if the number of pixels is sufficiently high, the statistically significant difference is expected between the distribution of pixel values of the first components in respective pairs and that of the pixel values of the second components in the respective pairs, as shown in FIG. 6.
FIG. 7 is a block diagram showing the constitution of a conventional digital watermark detection device for detecting corresponding watermark information from the image data into which watermark information has been embedded by the digital watermark embedding device 240 shown in FIG. 5 by means of a patchwork method.
In a digital watermark detection device 250 shown in FIG. 7, the same pair of pixels as those generated by the pixel value pair generation section 241 in the digital watermark embedding device 250 shown in FIG. 5, are generated by a pixel value pair generation section 261. The average of pixel values in the first component of the respective pairs is calculated by the first component average calculation section 262 and the average of pixel values in the second component of the respective pixels is calculated by the second component average calculation section 263.
Next, in an average comparison section 264, the two average values are compared and embedded watermark information is detected (recovered) by judging that 1 is embedded if the average of the pixel values in the first component is higher, and that 0 is embedded if the average of the pixels values in the second component is higher.
The above-stated conventional digital embedding and detection techniques have advantage in that watermark information is difficult to lose by various operations. On the other hand, these techniques, which require orthogonal transform such as DCT transform, have disadvantage in that complexity of computation for embedding and detecting watermark information and a hardware cost are large. That is, DCT transform is a kind of transform introduced by transforming form DFT and the complexity of computation is the same order. A processing of DFT can be performed with high speed by FFT algorithm, and, theoretically, the complexity of computation of the FFT for data of data size N is given as O (Nxc3x97log N).
Complexity of computation is roughly evaluated using, for example, a static image of W wide by H high. If this static image is divided into blocks of w wide by h high, the complexity of computation per block for the DCT transform is given as O (hxc3x97wxc3x97log w+wxc3x97hxc3x97log h)=O (wxc3x97hxc3x97log (wxc3x97h)). While the total number of blocks is (W/w)xc3x97(H/h), the total complexity of computation is:
O((W/w)xc3x97(H/h)xc3x97wxc3x97hxc3x97log(wxc3x97h))=O(Wxc3x97Hxc3x97log(wxc3x97h)).
The calculation ratio of a case where an image is a block per se to a case where an image is divided into blocks of w wide by h high is:
(log(Wxc3x97H))/(log(wxc3x97h)).
Here, if W=wxc3x972q and H=hxc3x972r, then
xe2x80x83(log(Wxc3x97H))/(log(wxc3x97h)).=(1+(p+q)/log2(wxc3x97h).
For example, if W=H=1024=1024 and w=h=32=25, then q=r=5 and (1+(p+q)/log2(wxc3x97h)=2. It follows that the processing speed at which an image is divided into small blocks each having a side which is {fraction (1/32)} as small as that of an image and DCT transform is conducted to the small blocks is about twice as fast as that at which DCT transform is conducted to an entire image.
However, since the hardware cost is large to mount FFT to a large size of the block with hardware, actually, the hardware mounting is often adapted to perform processing by repeatedly using small FFT. The complexity of computation in this case still becomes the order of the second power of the data size.
How wide the region into which watermark information can be dispersed and embedded will be depends on the complexity of computation of orthogonal transform such as DCT transform and time allowed to embed and detect the watermark information. If it is possible to take sufficient time to embed and detect watermark information, efficiency is not an important factor. From the viewpoint of robustness characteristics, if embedding and detection time falls within a realistic range, it is desirable to set the size of a block to be as large as possible.
In case of using watermark information for the control of use and rating, however, it is impossible to take a lot of time to detect watermark information. In case of using watermark information for finger print, it is impossible to take a lot of time to embed watermark information, either.
As stated above, according to the conventional digital watermark embedding and detection technique, in spite of the fact that it is desirable to select a large block size (such as 512xc3x97512 pixels and 720xc3x97720 pixels) and thinly and widely disperse watermark information in view of robustness characteristics and perceived non-revealment characteristics, processing for embedding and detecting watermark information cannot be efficiently conducted due to the problem of cost required for the calculation for orthogonal transform. As a result, the conventional technique is disadvantageous in that there is no other choice but to select a small block size (such as 16xc3x9716 pixels or 32xc3x9732 pixels) and to embed watermark information into the small blocks in case of application requiring high efficiency in the embedding and detection of watermark information.
Meanwhile, according to the conventional digital watermark embedding and detection technique by means of the patchwork method, although it is not required to conduct orthogonal transform such as DCT transform, image data into which watermark information is embedded does not have statistically uniform property. Owing to this, if the number of pixel pairs selected (generated) at random is small, no basis is formed on which it is judged whether the difference in statistical distribution between the first component and the second component in the pairs is due to the embedding operation or a failure to generate sufficient number of pixel pairs, for which reason statistical difference originally exists between the pairs selected by chance. As a result, the conventional technique is disadvantageous in that it requires sufficient number of pairs to make the statistically significant difference in distribution between the first and second components in the respective pairs after embedding operation and in that it is difficult to estimate the necessary number of pixel pairs to be generated during embedding and detection in advance.
It is, therefore, an object of the present invention to provide a digital watermark embedding device capable of efficiently embedding watermark information into target data even if a large block size is selected to divide the data.
It is another object of the present invention to provide a digital watermark detection device capable of efficiently detecting embedded watermark information even if large block size of information is selected or an entire image per se is treated as one block.
It is yet another object of the present invention to provide a digital watermark embedding device and a digital watermark detection device capable of estimating the necessary number of pixel pairs to be generated while watermark information is being embedded and detected by employing a patchwork method.
A digital watermark information according to the present invention is characterized by comprising an input section which inputs pixel value data of an image which is a target for embedding of watermark information; an embedded position selection section which determines a position in frequency domain into which the watermark information is to be embedded, irrespectively of a frequency component value; a frequency component value variation decision section which determines a variation of a frequency component value at each embedded position determined by the embedded position selection section; a pixel value variation calculation section which calculates a variation of a pixel value at each point in pixel value domain of the image based on the embedded position in frequency domain determined by the embedded position selection section and on the variation of a frequency component value determined by the frequency component value variation decision section; a pixel value conversion section which embeds watermark information by changing corresponding pixel value data of the image in accordance with the variation of a pixel value at each point in pixel value domain calculated by the pixel value variation calculation section; and an output section which outputs pixel value data of the image into which watermark information has been embedded.
As described above, with this constitution, watermark information is embedded not in frequency domain as in the conventional device but in pixel value domain. To this end, in the above constitution, a pixel value variation calculation section is provided to embed watermark information in pixel value domain. The pixel value variation calculation section calculates the variation of a pixel value at each point in pixel value domain, based on the position into which watermark information is to be embedded (embedded position) and on the variation of a frequency component value at that position. Although the calculation for obtaining the variation of a pixel value requires an arithmetic operation for obtaining matrix elements of orthogonal transform, the operation quantity is considerably small compared with that of orthogonal transform.
Here, it is possible to easily calculate the variation of a pixel value by the arithmetic operation in which when it is assumed that a variation of a pixel value at each point in pixel value domain of the image is xcex94f(x), the embedded position in frequency domain determined by the embedded position selection section is u and the variation of a frequency component value determined by the frequency component value variation decision section is xcex94F(u), the pixel value variation calculation section calculates an i-th matrix element Axe2x88x921(xi, ui) of orthogonal transform and calculates a variation xcex94f(x) of a pixel value from a calculation result in accordance with a formula:
xcex94f(x(1), . . . , x(n))=Axe2x88x921(x(1), u(1))xc2x7 . . . xc2x7Axe2x88x921(x(n), u(n))xc2x7xcex94F(u(1), . . . , u(n)),
where n is an integer equal to or higher than 1.
In this way, by conducting embedding of watermark information in pixel value domain, the above-stated constitution dispenses with orthogonal transformation for converting pixel value domain to frequency domain and inverse orthogonal transformation for converting frequency domain to pixel value domain conducted after embedding of watermark information in frequency domain, that is, dispenses with two orthogonal transformations which result in great complexity of computation, thereby making it possible to embed watermark information at high speed.
It is noted, however, that the conventional digital watermark technique is capable of determining a watermark information embedded position and the variation of a frequency component value from the frequency component value data of an image obtained by converting pixel value domain to frequency domain, whereas the above-stated constitution is not capable of dynamically determining a watermark information embedded position and the variation of a frequency component value. Nevertheless, since the above constitution dispenses with the conventionally required two orthogonal transformations and allows the size of a block as a unit for watermark embedding processing to be set sufficiently large compared with the conventional case, it is possible to diffuse and embed watermark information into a wide range. Thus, no problem occurs even if the watermark information embedded position is not determined from the frequency component data of the image.
It is, particularly, more desirable that the device is constituted such that a direct sequence spread spectrum method is applied to the above constitution, a pseudo-random number generation section, which generates a pseudo-random number by which a pixel value at each point in pixel value domain of the image is multiplied for spread spectrum, is provided, the variation of a pixel value at each point in pixel value domain of the image is calculated by the pixel value variation calculation section, based on the embedded position in frequency domain determined by the embedded position selection section, on the variation of a frequency component value determined by the frequency component value variation decision section and on the pseudo-random number corresponding to each point in the pixel value domain of the image and generated by the pseudo-random number generation section. This is because such a constitution makes it less necessary to dynamically determine the watermark information embedded position and the variation of a frequency component value in dependence on the frequency component data of the image.
If this spread spectrum method is employed, the variation of a pixel value can be calculated easily by the arithmetic operation in which when it is assumed that a variation of a pixel value at each point in pixel value domain of the image is xcex94f(x), the embedded position in frequency domain determined by the embedded position selection section is u, the variation of a frequency component value determined by the frequency component value variation decision section is xcex94F(u) and the pseudo-random number generated by the pseudo-random number generation means is p(x), the pixel value variation calculation section calculates an i-th matrix element Axe2x88x921(xi, ui) of orthogonal transform and calculates a variation xcex94f(x) of a pixel value from a calculation result in accordance with a formula:
xe2x80x83xcex94f(x(1), . . . , x(n))=p(x(1), . . . , x(n))xc2x7Axe2x88x921(x(1), u(1))xc2x7 . . . xc2x7Axe2x88x921(x(n), u(n))xc2x7xcex94F(u(1), . . . , u(n)),
where n is an integer equal to or higher than 1.
In addition, as for the variation of a frequency component value, it is possible to predetermine a variation which is higher than the absolute value of frequency component values at almost all embedded positions. In that case, no problem occurs even if orthogonal transform is not conducted.
To determine an embedded position, for example, a technique for setting a fixed position in frequency domain of the image as an embedded position, a technique for setting a position calculated from user inherent information as an embedded position and the like can be employed. Besides, a technique in which a fixed position is not set as an embedded position, information on the first number frame is fixed but the following embedded positions are determined based on the information read from the fixed frame (in which technique, watermark information is embedded in the first number frame with a predetermined fixed embedded position set as an embedded position, and a certain determined calculation is made according to the watermark information in the first number frame, thereby making it possible to calculate embedded positions in the following frames), a technique for setting a position calculated from user inherent information as an embedded position, a technique for passing an embedded position by means other than watermark information (in which technique, the method of calculating a watermark information embedded position is preset, the data used for embedding of watermark information and necessary for the calculation is fed to the digital watermark detection device not as watermark information embedded into image data but as data different from the image data and the digital watermark detection device calculates an embedded position from the received data and then determines the embedded position), a technique for generating an embedded position using random numbers, a technique for making the random number series different according to users and the like can be employed.
Further, if a plurality of embedded positions in frequency domain are determined for each block, a beat might possibly occur, depending on the embedded positions. Therefore, the embedded position selection section may be provided with a function of judging whether or not a beat occurs between a plurality of frequencies (a beat estimation section). Thus, every time an embedded position candidate is generated, this judging function judges the validity of the candidate. Namely, if it judges that the candidate is inappropriate, the candidate is discarded. If it judges that the candidate is appropriate, the candidate is selected as an element of a group of embedded positions. To do so, the embedded position selection section may consist of a frequency generation section which generates a plurality of embedded position candidates and a beat judging section which inputs a plurality of embedded position candidates generated by the frequency generation section, judges the degree of a beat based on the relationships of frequency component values among the candidates and selects and outputs a group of a predetermined number of embedded positions which can avoid the influence of the beat. It goes without saying that the embedded position selection section can be originally constituted to determine an embedded position which does not cause a beat (i.e., a watermark frequency).
Additionally, as for the variation of a frequency component value, a variation which is preset based on the frequency distributions of frequency component values for a plurality of images may be used. It is more desirable to employ a constitution that a digital watermark detection section, which calculates the frequency component value at the watermark information embedded position based on the image into which the watermark information is embedded by the pixel value conversion section and which feeds back the frequency component value or watermark information recovered from the frequency component value to the frequency component value variation decision section, is provided and that the variation of a frequency component value is adaptively changed based on the frequency component value or the watermark information fed back by this digital watermark detection section. It is further more desirable to employ a constitution that a filtering section, which inputs the image into which watermark information is embedded and which conducts predictable data operation to the image, is provided between the pixel value conversion section and the digital watermark detection section, that the digital watermark detection section calculates a frequency component value at the watermark information embedded position based on the image which has been subjected to this data operation, and that the frequency component value or the watermark information recovered from the frequency component value is fed back to the frequency component value variation decision section.
Furthermore, it is possible to employ a constitution that a frequency component value calculation section, which calculates a frequency component value at each embedded position determined by the above embedded position selection section based on a pixel value at each point in the pixel value domain of the image, is provided and that the frequency component value variation decision section determines the variation of a frequency component value at each embedded position based on the frequency component value at each embedded position. If the spread spectrum method is used, a frequency component value calculation section, which calculates a frequency component value at each embedded position determined by the embedded position selection section based on each embedded position, on a pixel value at each point in the pixel value domain of the image and on the pseudo-random number generated by the pseudo-random number generation section and corresponding to each point in the pixel value domain of the image, may be provided and the frequency component value variation decision section may determine the variation of a frequency component value at each embedded position based on the frequency component value at each embedded position.
In this way, by obtaining a frequency component value at an embedded position, i.e., frequency component values at a small number of points and thereby determining the variation of a frequency component value, it is possible to make a setting such that perceived influence on the image may be reduced and that the variation of a frequency component value due to embedding may be suppressed to be small while using information on general properties about the variation of a frequency component value under various operations (such as a property that the variation of any frequency component value falls within a certain range).
Next, a digital watermark detection device for inputting pixel value data of an image into which watermark information is embedded and detecting the watermark information, according to the present invention is characterized by comprising an embedded position selection section which determines a position in frequency domain into which the watermark information is embedded; a frequency component value calculation section which calculates a frequency component value at each embedded position based on pixel value data of an image into which the watermark information has been embedded and on each embedded position determined by the embedded position selection section; and a watermark information recovery section which recovers the watermark information based on the frequency component value at each embedded position calculated by the frequency component value calculation section.
In this way, with the above constitution, a frequency component value at each embedded position determined by the embedded position selection section is calculated based on a pixel value at each point in the pixel value domain of the image into which watermark information has been embedded and watermark information is recovered based on the frequency component value at the embedded position. Due to this, compared with the conventional detection device which converts the pixel value data of the image into which watermark information is embedded from that in pixel value domain to that in frequency domain by orthogonal transform, acquires frequency component data forming the image data in frequency domain and detects watermark information from the frequency component value data, the device according to the present invention does not require conducting orthogonal transform to thereby decrease the operation quantity and to allow high-speed processing.
Here, the frequency component value can be easily calculated by the arithmetic operation in which when it is assumed that a pixel value at each position in pixel value domain of the image into which the watermark information is embedded is f(x) and the embedded position in frequency domain determined by the embedded position selection section is u, the frequency component value calculation section calculates an i-th matrix element A(ui, xi) of orthogonal transform and calculates a frequency component value F(u) at the embedded position u from a calculation result in accordance with a formula:
xcex94F(u(1), . . . , u(n))=xcexa3x(0) . . . xcexa3x(n)Axe2x88x921(x(1), u(1))xc2x7 . . . xc2x7Axe2x88x921(x(n), u(n))xc2x7xcex94f(x(1), . . . , x(n)).
Further, in the digital watermark detection device which employs a direct sequence spread spectrum method and treats an image into which watermark information is embedded as a target for detection of the watermark information, a frequency component value at each embedded position is calculated by the frequency component value calculation section based on the pixel value data of the image into which the watermark information is embedded, on each embedded position determined by the embedded position selection section and on the pseudo-random number series used for spread spectrum. Thus, high-speed processing can be realized.
Here, the frequency component value can be easily calculated by the arithmetic operation in which when it is assumed that a pixel value at each position in pixel value domain of the image into which the watermark information is embedded is f(x), the embedded position in frequency domain determined by the embedded position selection section is u and the pseudo-random number generated by the pseudo-random number generation means is p(xi), the frequency component value calculation section calculates an i-th matrix element A(ui, xi) of orthogonal transform and calculates a frequency component value F(u) at the embedded position u from a calculation result in accordance with a formula:
xcex94F(u(1), . . . , u(n))=xcexa3x(0) . . . xcexa3x(n)p(x(1), . . . , x(n))xc2x7Axe2x88x921(x(1), u(1))xc2x7 . . . xc2x7Axe2x88x921(x(n), u(n))xc2x7xcex94f(x(1), . . . , x(n)).
Meanwhile, it is possible to constitute a digital watermark embedding and detection device provided with both the digital watermark embedding function of the above digital watermark embedding device and the digital watermark detection function of the above digital watermark detection device. In this device, parts common to the both functions are shared between them, thereby making the constitution simple.
Moreover, the present invention is characterized by comprising an input section which inputs pixel value data of an image which is a target for embedding watermark information; a frequency component pair generation section which determines a pair of frequency components at positions in frequency domain into which the watermark information is to be embedded, irrespectively of a frequency component value; a pseudo-random number generation section which generates a pseudo-random number by which a pixel value at each point in pixel value domain of the image is multiplied for spread spectrum; a direct sequence spectrum spreading section which outputs pixel value data spectrum-spread by multiplying pixel value data of the image by the pseudo-random number generated by the pseudo-random number generation section; an orthogonal transformation section which orthogonally transforms the pixel value data spectrum-spread by the direct sequence spectrum spreading section and generates frequency component value data; a first component change section which changes a frequency component value, generated by the orthogonal transformation section, of the first component in the pair of frequency components at the embedded positions generated by the frequency component pair generation section, using a value of the watermark information; a second component change section which changes a frequency component value, generated by the orthogonal transformation section, of the second component in the pair of frequency components at the embedded positions generated by the frequency component pair generation section, using the value of the watermark information, the second component change section changing the frequency component in an opposite direction to that for the change by the first component change means; a reverse-orthogonal transformation section which reverse-orthogonally transforms the frequency component value data changed by the first component change section and the second component change section, and which outputs pixel value data; an inverse spectrum spreading section which conducts inverse spectrum spreading by multiplying the pixel value data outputted from the reverse-orthogonal transformation section by the pseudo-random number generated by the pseudo-random number generation section, and which outputs pixel value data of the image into which the watermark information has been embedded; and an output section which outputs the pixel value data of the image into which the watermark information has been embedded.
As described above, the constitution of the device is characterized in that the patchwork method is not directly applied to the pixel value data of an image but that direct sequence spectrum spreading is conducted by multiplying the pixel value data of the image by the PN sequence random number value, the resultant image data is subjected to orthogonal transformation, a pair of frequency components are generated at random for the transformed image data and thereafter the patchwork method is applied.
The frequency component data obtained by subjecting the image data to orthogonal transformation by direct sequence spectrum spreading has statistically almost uniform distribution close to normal distribution. Therefore, even if the number of frequency component pairs at embedded positions selected at random is small, the statistically significant difference occurs between the frequency component value distributions of the first component (one component) and the second component (the other component) of the pairs after change operations of the first and second component change sections, by the change operations, thereby making significant watermark embedding possible. This facilitates estimating, in advance, the necessary number of pixel pairs to be generated during embedding of watermark information.
Furthermore, a digital watermark detection device, which employs a new patchwork method stated above, inputs the pixel value data of an image into which watermark information is embedded and detects watermark information, a digital watermark detection device for inputting pixel value data of an image into which watermark information is embedded and detecting the watermark information, according to the present invention is characterized by comprising a frequency component pair generation section which determines a pair of frequency components at positions in frequency domain into which the watermark information is to be embedded, irrespectively of a frequency component value; a pseudo-random number generation section which generates a pseudo-random number by which a pixel value at each point in pixel value domain of the image is multiplied for spread spectrum; a direct sequence spectrum spreading section which outputs pixel value data spectrum-spread by multiplying pixel value data of the image at each point in pixel value domain by the pseudo-random number generated by the pseudo-random number generation section; an orthogonal transformation section which orthogonally transforms the pixel value data spectrum-spread by the direct sequence spectrum spreading section and generates frequency component value data; a first component average calculation section which calculates an average of frequency component values, generated by the orthogonal transformation section, of the first component in the pairs of frequency components at respective embedded positions generated by the frequency component pair generation section; a second component average calculation section which calculates an average of frequency component values, generated by the orthogonal transformation section, of the second component in the pairs of frequency components at respective embedded positions generated by the frequency component pair generation section; and an average comparison section which compares the two averages calculated by the first component average calculation section and the second component average calculation section, and recovers the watermark information based on the comparison result.
As stated above, if conducting direct sequence spectrum spreading by multiplying the pixel value data of the image into which watermark information is embedded by the PN sequence random number value, subjecting the resultant image data to orthogonal transformation and calculating averages of the first component and second component in the frequency component pair at the watermark embedded positions, respectively, then averages close to normal distributions can be obtained. This allows the embedded watermark information to be recovered (detected) with high accuracy by comparing the averages and facilitates estimating, in advance, the necessary number of pixel pairs to be generated during the detection of watermark information.
As described so far in detail, according to the present invention, during embedding of watermark information, even if a large block size is selected, calculation costs required for direct sequence spectrum spreading, inverse spectrum spreading, orthogonal transform and reverse-orthogonal transform can be made lower, therefore, high-speed embedding of watermark information can be realized. Owing to this, while there has been conventionally no other choice but to mount the device as hardware in view of performance, it is possible to mount the device or functions as software according to the present invention. In addition, if the function of embedding watermark information is to be realized by a hardware circuit, it can be realized at lower hardware cost than the conventional cost.
Further, according to the present invention, it is possible to prevent the loss of watermark information against various operations including, for example, D/A conversion and A/D conversion while a large block size is selected and the visual degradation of the image is suppressed to be small.
Moreover, according to the present invention, by embedding watermark information at high speed, it is possible to realize a fingerprinting device for embedding information on users and transfer destinations when data such as an image is used and transferred.
Additionally, according to the present invention, by detecting watermark information at high speed, it is possible to apply the present invention to a case of embedding information on control of use and copy control and descramble keys into data such as image, to transfer these pieces of information together with the data and to detect the information instantly when they are used.
According to the present invention, by detecting and embedding a digital watermark at high speed, use method such that the use control, copy control information, and descramble key are extracted from the data of the image etc., the watermark information is erased immediately, another watermark information is superimposed, and watermark information is altered in another watermark information based on those information is possible, when distributing and using.
Furthermore, according to the present invention, even if the orthogonal transformation in which FFT is used is not performed, since a high-speed embedding or detection is possible, the size of the block need not be set in the power of two, and the block of an arbitrary size can be selected. Therefore, to the image and the block with a size different from the power of two, special processing need not be performed about the remainder or the lack part. In addition, when watermark information of arbitrary size (n) is embedded into the image of arbitrary size (Wxc3x97H) by using this character, special processing to the remainder and the lack part caused by division need not be performed by the block division of w=W/n1, h=H/n2 and n1xc3x97n2xe2x89xa7n.
Furthermore, according to the present invention, the patchwork method is not directly applied to the pixel value data of an image. But, after spread spectrum is conducted by multiplying the pixel value data of the image by the PN sequence random number, the resultant image data is subjected to orthogonal transformation, a pair of frequency components at embedded positions are generated at random for the transformed image data and then the patchwork method is applied. By doing so, even if the number of frequency component pairs at embedded positions is small, the statistically significant different occurs between the distributions of frequency component values of the first and second components in the pair after change operations are conducted to the first and second components, respectively. As a result, it is possible to realize significant watermark embedding and highly accurate watermark detection, thereby providing higher-speed processing.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.

Digital watermark embedding device, digital watermark detection device and recording medium recording computer readable program for realizing functions of two devices


An on-board control apparatus includes: a controller connected to a controlled device mounted in a vehicle via a signal line and configured to control the operation of the corresponding controlled device; and a power source box connected to a power source mounted in the vehicle via a power line, that is connected to the controlled device mounted in the vehicle via a power line, and configured to switch between supply and non-supply of power from the power source to the controlled device, wherein the power source box includes; a switch disposed in a power supply path from the power source to the controlled device; a reception unit configured to receive an input of the switching command; and a switching control unit configured to switch between conduction and interruption of the switch in response to the switching command received by the reception unit.

A large number of devices are mounted in a vehicle, and these devices operate by being supplied with power from an on-board power source such as a battery. An apparatus called a power source box is provided in the power supply path from the power source to each device. The power source box is connected to the power source via a power line, and is connected to the devices via individual power lines. A plurality of switches are built in the power source box, and supply and non-supply of power from the power source to the device can be switched. On the other hand, the operation of the device mounted in the vehicle is performed by, for example, an ECU (Electronic Control Unit). In a conventional vehicle, the ECU controls the switching of each switch of the power source box, thereby switching between supply and non-supply of power to the device to be controlled by that ECU.
In JP 2015-217734A, a power source apparatus for an automobile having a configuration is proposed in which, in a power source box interposed between a plurality of storage batteries and loads, a switch means for selecting whether to supply power from each storage battery to the load and a switch control unit that controls the switch means to select a storage battery that supplies power according to the output voltage value of each storage battery are provided, so that a storage battery selection operation can be performed by the switch control unit based on a control signal that is output from a load control unit that controls the loads.
In recent years, the number of devices mounted in a vehicle has increased, and it has been studied to reduce the number of devices by integrating (uniting) a plurality of devices into one device. As one plan for integration, it is conceivable to integrate the above-mentioned ECU and the power source box into one apparatus. In this case, a device to be controlled is connected to the ECU integrated with the power source box via a signal line and a power line, and the ECU performs operation control and power source control in an integrated manner.
However, in the configuration in which the ECU integrated with the power source box performs the operation control and the power source control of the device in an integrated manner, when a plurality of devices to be controlled are disposed at separate locations in the vehicle, the power line connecting the ECU and each device becomes long. As a result, the amount of the power lines mounted in the vehicle may increase.
The present disclosure has been made in view of such circumstances, and an object thereof is to provide an on-board power supply system and an on-board control apparatus capable of reducing the number of devices mounted in a vehicle by integrating a power source box and an ECU, and suppressing an increase in the amount of power lines in the vehicle.

On-board power supply system and on-board control apparatus


According to a method of simulation processing, an instrumented simulation executable model of a design is built by compiling one or more hardware description language (HDL) files specifying one or more design entities within the design and one or more instrumentation entities and instantiating instances of the one or more instrumentation entities within instances of the one or more design entities. Operation of the design is then simulated utilizing the instrumented simulation executable model. Simulating operation includes each of multiple instantiations of the one or more instrumentation entities generating a respective external phase signal representing an occurrence of a particular phase of operation and instrumentation combining logic generating from external phase signals of the multiple instantiations of the one or more instrumentation entities an aggregate phase signal representing an occurrence of the particular phase.

1. Technical Field
The present invention relates in general to designing and simulating digital devices, modules and systems, and in particular, to a method and system for computer simulation of digital devices, modules and systems utilizing a hardware description language (HDL) model.
2. Description of the Related Art
Verifying the logical correctness of a digital design and debugging the design, if necessary, are very important steps in most digital design processes. Logic networks are tested either by actually building networks or by simulating networks on a computer. As logic networks become highly complex, it becomes necessary to simulate a design before the design is actually built. This is especially true when the design is implemented as an integrated circuit, since the fabrication of integrated circuits requires considerable time and correction of mistakes is quite costly. The goal of digital design simulation is the verification of the logical correctness of the design.
In a typical automated design process that is supported by a conventional electronic computer-aided design (ECAD) system, a designer enters a high-level description utilizing a hardware description language (HDL), such as VHDL, producing a representation of the various circuit blocks and their interconnections. The ECAD system compiles the design description into a format that is best suited for simulation. A simulator is then utilized to verify the logical correctness of the design prior to developing a circuit layout.
A simulator is typically a software tool that operates on a digital representation, or simulation model of a circuit, and a list of input stimuli (i.e., testcase) representing inputs of the digital system. A simulator generates a numerical representation of the response of the circuit, which may then either be viewed on the display screen as a list of values or further interpreted, often by a separate software program, and presented on the display screen in graphical form. The simulator may be run either on a general-purpose computer or on another piece of electronic apparatus, typically attached to a general purpose computer, specially designed for simulation. Simulators that run entirely in software on a general-purpose computer will hereinafter be referred to as "software simulators". Simulators that are run with the assistance of specially designed electronic apparatus will hereinafter be referred to as "hardware simulators".
Usually, software simulators perform a very large number of calculations and operate slowly from the user's point of view. In order to optimize performance, the format of the simulation model is designed for very efficient use by the simulator. Hardware simulators, by nature, require that the simulation model comprising the circuit description be communicated in a specially designed format. In either case, a translation from an HDL description to a simulation format, hereinafter referred to as a simulation executable model, is required.
The present invention appreciates that certain events, such as reaching the end of a particular simulation testcase, are difficult to detect in a conventional simulation executable model. For example, in conventional simulation environments, a designer may detect the occurrence of the end of a testcase by incorporating into the simulation executable model special-purpose, hand-built logic to monitor specific signals for which a particular set of values indicates that the end of a testcase has been reached. In some cases, the complexity of such monitoring logic may approach the complexity of the simulated circuit being monitored. Consequently, the present invention appreciates that it would be useful and desirable to provide a method, system and program product that improve the detection and visibility of certain events, such as end of testcase events, within simulation executable models.

Method, system and program product supporting phase events in a simulation model of a digital system


A mounting system is provided for readily mounting an electrical connector in an opening in a panel for interconnecting an electrical device on one side of the panel with an electrical component on the other side of the panel. A complementary interengaging pivot arrangement is provided between a nose of the connector and the panel, near the opening in the panel, whereby the connector can be rotated to an operative position in the opening. Complementary interengaging latches are provided between the connector and the panel, near the opening and remote from the pivot means, for holding the connector in its operative position. Interengaging stops are provided for preventing disengagement of the pivot arrangement when the connector is in its operative position.

It is a continuing problem to provide systems for securely mounting electrical connectors on support structures, particularly in environments where the connectors must be replaced or interchanged. This is particularly true in situations where the connector is mounted to a support panel, such as in an opening in the panel, to interconnect an electrical device on one side of the panel with an electrical component on the other side of the panel.
For instance, in mobile telephone systems, a base unit is provided with a receptacle for receiving a telephone handset. The handset is battery powered and terminals are exposed on the handset, usually at one end thereof, so that the handset can be mounted on the base unit for recharging or for data retrieval purposes. The exposed terminals at the one end of the handset, when positioned in the receptacle, engage terminals of an electrical connector. The connector terminals interconnect the handset terminals with an electrical component, such as a printed circuit board, within the base unit.
In various electronic devices, such as the mobile telephone system described above, the electrical connector often is subjected to considerable abuse, such as repeated repositioning of the telephone handset into the receptacle of the base unit. Consequently, the electrical connector becomes damaged and/or worn and must be replaced more often than electrical connectors in many other environments. Heretofore, such electrical connectors have been mounted by separate fasteners, and tools, sometimes special tools, are required to install, remove or interchange the connectors. This is time consuming, adds to the cost of manufacturing and assembling the device, and is not consumer oriented.
Therefore, there is a need for a very simple mounting system for electrical connectors of the character described, particularly a mounting system which has latches requiring no extraneous components, and wherein the latches secure the connector in all directions.

Mounting system for electrical connectors


Methods, systems, and products create anonymous loan documents. Electronic loan documents are prepared for a borrower of a loan. An anonymous shadow copy of the electronic loan documents is generated that removes personally identifying information, such as names, addresses, and social security numbers. The anonymous shadow copy of the electronic loan documents may then be electronically published.

The exemplary embodiments generally relate to mortgages and, more particularly, to safeguarding personal information in mortgage applications.
A borrower applying for a reverse mortgage loan must get counseling from an independent counselor. This independent counselor is not permitted to have direct contact with a lender of the reverse mortgage loan. The counselor, though, should have access to loan documents prepared by the lender. A conventional solution is for the borrower to mail, electronically send, or physically present the loan documents to the counselor prior to or at counseling. This conventional solution, though, is cumbersome for the borrower. Another conventional solution is to publish the loan documents on a website, so the counselor may electronically access the loan documents via the Internet. Because the loan documents are borrower-specific and contain confidential information, a complicated authentication procedure is required.

Methods, systems, and products for anonymous loan documents


According to an aspect of the present disclosure, an airfoil apparatus is provided which minimizes entry of entrained air into a system having a controlled internal environment, such as a corona treatment system, such entrained air resulting from a high-speed web moving into the system. According to another aspect of the present disclosure, the airfoil apparatus is rotatable relative to the system so that the airfoil apparatus can be adjusted to changes in the web.

Corona treatment is a method using an electrical corona discharge to modify a surface of a web to improve its ability to accept inks and adhesives. In a corona treatment system, a high voltage electrode is mounted parallel to and spaced from a ground roller, which forms a grounded electrode. The air gap between the electrode and the ground roller is energized, forming a corona, which, when web is passed therethrough modifies the material the web is formed of, and makes the web more receptive to ink and adhesives. Corona will be produced anywhere there is air within this air gap.
The web is moving a high speed. As the web enters into the corona treatment system, the web passes through a pair of nip rollers, and may pass through a secondary pair of nip rollers. The web is routed around idler rollers and then through the air gap between the electrode and the ground roller. After the web is treated, the web exits the corona treatment system.
It is desired for the air within the corona treatment system to be kept inert to provide for a better reaction within the air gap. When a web is moving at high speed, the web entrains air in the ambient atmosphere and enters into the corona treatment system through the nip rollers. The air has a tendency to permeate the corona treatment system which may result in an undesirable reaction in the corona treatment system.

Airfoil apparatus for a system having a controlled internal environment


A method for generating a control signal to a conveyor system, the conveyor system configured to serve at least a plurality of robots, includes receiving, in a control entity, a service call for a first robot, the service call being associated with a priority of the first robot; determining, by the control entity, the priority of the first robot; and generating, by the control entity, a control signal to the conveyor system to serve the service call for the first robot in accordance with the determined priority of the first robot. A control entity, a robot and a system are also provided.

Conveyor systems, like elevators, are configured to serve users by conveying the users from one position to another, such as from one floor to another floor in a building. The conveyor system is typically configured to carry human passengers and the conveyor systems are mainly developed for that purpose. Due to human character many parameters of the conveyor system, and thus functionalities, to serve the human passengers need to be considered from the user experience point of view. This kind of parameters may e.g. relate to waiting/service time of the human passengers with the conveyor system.
On the other hand, a technical development in other technical areas have enabled a development of at least partially autonomous devices to operate within an area or a space. The at least partially autonomous device may refer to robots, such as mobile robots, which may travel e.g. in a controlled manner within the area or the space. The robots may be configured to cooperate with other devices and/or systems, such as with the conveyor systems as described. The cooperation may e.g. refer to a communication in one way or another between the mentioned entities. Moreover, one entity may utilize services of the other entity. For example, the robot may travel with the conveyor system from one position to another. For example, the robot may be configured to enter an elevator car and communicate with the conveyor system in such a manner that the conveyor system carries the robot from one floor to a destination floor.
The cooperation between the conveyor systems and the robots have established further challenges in order to serve the passengers, being they either human passengers or robot passengers, in a manner that satisfy the need. For example, the robots, as passengers, do not have any similar characters to humans where e.g. waiting for a service causes frustration. However, the existing conveyor systems do not take into account the needs of different kinds of passengers and, hence, there is need to develop solutions which may mitigate at least in part drawbacks of the existing solutions.

Generation of a control signal to a conveyor system