The present invention is embodied in a system and method for performing spectral analysis of a digital signal having a discrete duration by spectrally decomposing the digital signal at predefined frequencies uniformly distributed over a sampling frequency interval into complex frequency coefficients so that magnitude and phase information at each frequency is immediately available to produce a modulated complex lapped transform (MCLT). The system includes real and imaginary window processors and real and imaginary transform processors. The real and imaginary window processors receive the input signal and apply and compute butterfly coefficients for the real and imaginary parts of the signal to produce resulting real and imaginary vectors, respectively. The real and imaginary transform processors compute spatial transforms on the real and imaginary vectors to produce real and imaginary transform coefficient of the MCLT, respectively. The MCLT is a biorthogonal spectral transformation system, in the sense that the original time domain signal can be reconstructed exactly by an inverse MCLT operator.

1. Field of the Invention
The present invention relates to a system and method for producing modulated complex lapped transforms (MCLTs), and in particular, a system and method for incorporating complex coefficients to modulated lapped transforms (MLTS) to derive MCLTs.
2. Related Art
In many engineering and scientific applications, it is desirable to analyze a signal in the frequency domain or represent the signal as a linear superposition of various sinusoids. The analysis of the amplitudes and phases of such sinusoids (the signal spectrum) can be useful in multimedia applications for operations such as noise reduction, compression, and pattern recognition, among other things. The Fourier transform is a classical tool used for frequency decomposition of a signal.
The Fourier transform breaks a signal down to component frequencies. However, its usefulness is limited to signals that are stationary, i.e., spectral patterns of signals that do not change appreciably with time. Since most real-world signals, such as audio and video signals, are not stationary signals, localized frequency decompositions are used, such as time-frequency transforms. These transforms provide spectral information that is localized in time.
One such transform is the discrete cosine transform (DCT). The DCT breaks a signal down to component frequencies. For instance, a block of M samples of the signal can be mapped to a block of M frequency components via a matrix of Mxc3x97M coefficients. To ensure a good energy compaction performance, the DCT approximates the eigenvectors of the autocorrelation matrix of typical signal blocks. Basis functions for the DCT (for type II) can be defined as:       a    nk    =            c                    (        k        )                                2        M                        cos                    [                              (                          n              +                              1                2                                      )                                                        k                                            xe2x80x83                                          π                        M                          ]
where,
ank is the element of an A transformation matrix in the nth row and
kth column, or equivalently, the nth sample of the kth basis function. For orthonormality, the scaling factors are chosen as:       c              (      k      )        ≡      {                                        1            /                          2                                                                          if                                            xe2x80x83                                          k                        =            0                                                1                          otherwise
The transform coefficients X(k) are computed from the signal block samples x(n) by:       X              (      k      )        =            ∑              n        =        0                    M        -        1                        xe2x80x83                          a        nk                          x                          (          n          )
The DCT can be used for convolution and correlation, because it satisfies a modified shift property. Typical uses of the DCT are in transform coding, spectral analysis, and frequency-domain adaptive filtering.
An alternative transform for spectral analysis is the discrete cosine transform, type IV (DCT-IV). The DCT-IV is obtained by shifting the frequencies of the DCT basis functions in eqn. (A) by xcfx80/2M, in the form:       a    nk    =                    2        M                        cos                    [                              (                          n              +                              1                2                                      )                                          (                          k              +                              1                2                                      )                                          π            M                          ]
Unlike the DCT, the scaling factor is identical for all basis functions. It should be noted that the DCT-IV basis functions have a frequency shift, when compared to the DCT basis. Nevertheless, these transforms still lead to orthogonal basis.
The DCT and DCT-IV are useful tools for frequency-domain signal decomposition. However, they suffer from blocking artifacts. In typical applications, the transform coefficients X(k) are processed in some desired way: quantization, filtering, noise reduction, etc. Reconstructed signal blocks are obtained by applying the inverse transform to such modified coefficients. When such reconstructed signal blocks are pasted together to form the reconstructed signal (e.g. a decoded audio or video signal), there will be discontinuities at the block boundaries.
The modulated lapped transform (MLT) eliminates such discontinuities. The MLT is a particular form of a cosine-modulated filter bank that allows for perfect reconstruction. For example, a signal can be recovered exactly from its MLT coefficients. Also, the MLT does not have blocking artifacts, namely, the MLT provides a reconstructed signal that decays smoothly to zero at its boundaries, avoiding discontinuities along block boundaries. In addition, the MLT has almost optimal performance for transform coding of a wide variety of signals. Because of these properties, the MLT is being used in many applications, such as many modern audio and video coding systems, including Dolby AC-3, MPEG-2 Layer III, and others.
However, one disadvantage of the MLT for some applications is that its transform coefficients are real, and so they do not explicitly carry phase information. In some multimedia applications, such as audio processing, complex subbands are typically needed by noise reduction devices, via spectral subtraction, and acoustic echo cancellation devices.
Therefore what is needed is a new transformation system and method that produces complex subbands for multimedia devices and audio processing devices, such as noise reduction devices and echo cancellation devices. Whatever the merits of the above mentioned systems and methods, they do not achieve the benefits of the present invention.
To overcome the limitations in the prior art described above, and to overcome other limitations that will become apparent upon reading and understanding the present specification, the present invention is embodied in a system and method for performing spectral analysis of a digital signal having a discrete duration. The present invention performs spectral analysis by spectrally decomposing the digital signal at predefined frequencies uniformly distributed over a sampling frequency interval into complex frequency coefficients so that magnitude and phase information at each frequency is immediately available.
Namely, the system of the present invention produces a modulated complex lapped transform (MCLT) and includes real and imaginary window processors and real and imaginary transform processors. Each window processor has window functions and operators. The real window processor receives the input signal as sample blocks and applies and computes butterfly coefficients for the real part of the signal to produce resulting real vectors. The imaginary window processor receives the input signal as sample blocks and applies and computes butterfly coefficients for the imaginary part of the signal to produce resulting imaginary vectors. The real transform processor computes a spatial transform on the real vectors to produce a real transform coefficient for the MCLT. The imaginary transform processor computes a spatial transform on the imaginary vectors to produce an imaginary transform coefficient for the MCLT.
In addition, the system can include inverse transform module for inverse transformation of the encoded output. The inverse transform module can include components that are the exact inverse of the inverse real and imaginary transform processors and the real and imaginary inverse window processors. The encoded output is received and processed by inverse real and imaginary transform processors, and then received and processed by real and imaginary inverse window processors to produce an output signal that substantially matches the input signal.
The foregoing and still further features and advantages of the present invention as well as a more complete understanding thereof will be made apparent from a study of the following detailed description of the invention in connection with the accompanying drawings and appended claims.

System and method for producing modulated complex lapped transforms


The present invention provides an immunoconjugate having the formula: T-c-En-c-Fcn or T-c-Fcn-c-En; wherein, T is a single chain variable portion fragment of a monoclonal antibody (scFv) directed to a target protein, polypeptide, or fragment thereof, which is highly expressed on cancer cells; E is two or more foreign immunogenic CD8+ T cell antigenic epitopes; c is a peptide or polypeptide fragment thereof, capable of being cleaved by a specific protease; and Fc is two or more Fc portions of an IgG antibody. Nucleic acid sequences encoding the same and vectors containing said nucleic acid sequences are also provided. Methods of making the immunoconjugate, along with methods of making target cells susceptible to CTL mediated cell killing, and methods for treatment of cancers are also provided.

Antigen-specific immunotherapy is important for its ability to harness the immune system to specifically target tumors without the toxicity associated with traditional chemoradiation. Cytotoxic CD8+ T lymphocytes (CTLs) can selectively kill tumor cells at multiple sites throughout the body. Furthermore, antigen-specific immunotherapy is unlikely to generate non-specific autoimmunity. However, antigen-specific immunotherapy targeting tumor-associated endogenous antigen faces the major obstacle of immune tolerance.
A need continues to exist for novel modes of immunotherapy which can effectively target specific cancers without stimulating the tolerance mechanisms of the patient's immune system.

Compositions and methods for rendering tumor cells susceptible to CD8+ T cell-mediated killing


An internal gear pump includes a pump rotor (4) in which a meshing point between an inner rotor (2) having n teeth and an outer rotor (3) having (n+1) teeth is located rearward, in a rotational direction of the rotor, relative to an eccentric axis (CL) along which a center (OI) of the inner rotor and a center (OO) of the outer rotor are disposed. A tooth-surface curve of the outer rotor (3) near a meshing section thereof is formed by duplicating thereto a tooth-surface shape of the inner rotor (2) near a meshing section thereof.

An internal gear pump formed by accommodating a pump rotor, which is constituted of a combination of an inner rotor and an outer rotor that are eccentrically disposed, within a rotor chamber of a housing is used as, for example, an oil pump for lubricating a vehicle engine or for an automatic transmission (AT).
The internal gear pump has an intake port and a discharge port in an end surface of the rotor chamber of the housing. A section between a terminal end of the intake port and a start end of the discharge port serves as a containment section that separates a chamber (i.e., a pump chamber) formed between the teeth of the inner rotor and the outer rotor from the intake port and the discharge port. While the aforementioned chamber moves and increases in area (volume) toward the intake port, liquid is taken into the chamber. Moreover, while the chamber moves and decreases in area toward the discharge port, the liquid within the chamber is delivered to the discharge port.
With regard to this internal gear pump, the tooth profile of the inner rotor is formed based on the following method disclosed in Patent Literature 1. With regard to the tooth profile designed based on this method (which will be described in detail later), the tooth height can be freely increased. Therefore, by increasing the volume of the chamber, the discharge rate of the pump can be increased.
By combining the inner rotor whose tooth profile is formed based on the method disclosed in Patent Literature 1 with an outer rotor whose tooth profile is formed based on the following method disclosed in Patent Literature 2, a pump rotor with relatively smooth rotation can be realized. Therefore, the tooth profile of the outer rotor to be combined is formed based on the method disclosed in Patent Literature 2.
The method disclosed in Patent Literature 2 involves revolving the center of the inner rotor along a circle having a diameter of (2e+t) (where e denotes an amount of eccentricity between the inner rotor and the outer rotor and t denotes a tip clearance between the inner rotor and the outer rotor), and rotating the inner rotor (1/n) times per revolution. An obtained envelope of a group of tooth-surface curves of the inner rotor serves as the tooth profile of the outer rotor.


A sun protection system for a transportation vehicle has plurality of LCD zones laminated into one or more glazings of the vehicle. An occupant sensor detects an expanse of at least one occupant in the vehicle. A navigation system determines a vehicle location, a date and time value, and a heading. External and internal temperature sensors sense outside and inside temperatures. A controller generates respective drive signals for the respective LCD zones in a manual mode and in an automatic mode. The controller compares a temperature difference between the outside temperature and the inside temperature to a temperature threshold. The respective drive signals provide substantially zero attenuation if the temperature difference is less than the temperature threshold while in the automatic mode.

The present invention relates in general to sun protection for the passenger compartment of motor vehicles, and, more specifically, to LCD dimming screens incorporated into the glazings of a motor vehicle.
The shining of direct sunlight into the passenger compartment of a transportation vehicle through any of its window glazings can give rise to the separate problems of glare and heat. The glare reduces the driver's visibility and can be a distraction to the driver and any passengers. Heating of the passenger compartment can result in an increased use of the vehicle air conditioning system which results in increased fuel consumption in an internal combustion vehicle and increased charge depletion for an electric vehicle.
In prior attempts to reduce problems from direct sunlight, tinted glass has been used in the glazings. Tinting is an incomplete solution because it cannot be placed in all areas of the glazings and because the locations of tinting may not correspond to the actual direction of direct sunlight to the driver's eyes at any particular time. Furthermore, tinting reduces visibility when it is dark. On the other hand, with a very bright sun in hot conditions the amount of tinting normally applied may be inadequate to block sufficient sunlight. Furthermore, tinting is not adaptable to current conditions. For example, tinting keeps out sunlight that would provide beneficial heating of the passenger compartment on a cold day. In that instance, the heating that could have been obtained using solar energy for free instead has to be made up for by a heater powered by the vehicle using its energy source (gasoline or battery charge).
Another conventional solution to the heat and glare of direct sunlight has been the use of blocking shades or other mechanical means to selectively deploy over certain window glazings to block to the sunlight. One typical blocking shade is the sun visor usually attached near the top of the windshield for the driver and front seat passenger. Sun visors can be distracting since the driver or passenger must continually physically move the sun visor as the vehicle changes direction. Furthermore, sun visors may be deployed in the same area where an air bag deploys during a crash (e.g., a side curtain airbag), resulting in interference with the air bag deployment. The presence of temporary shades such as a baby shade which attaches by suction cups to a window may also be undesirable during crash events.
Currently known systems let in too much sunlight when and where it is not needed and they otherwise block sunlight when it could be useful. Thus, it would be desirable to better control the blocking or attenuation of direct sunlight in order to reduce the load on climate control systems to compensate for the sunlight to thereby improve fuel economy and to improve driver vision with less glare thereby increasing overall safety.

Sun protection system for automotive vehicle


An RF receiver includes a plurality of OFDM modules. The OFDM modules include receiver antennas for substantially simultaneously receiving a plurality of transmission signals transmitted via a single frequency band having a plurality of sub-channels. Further included is a channel estimation module connected to the plurality of OFDM modules, and a channel compensation module connected to the channel estimation module and the plurality of OFDM modules. For each sub-channel, the channel estimation module is capable of estimating channel frequency responses affecting the transmission signals, and the channel compensation module is capable of compensating the transmission signals according to the estimated channel frequency responses. The receiver allows an improved transfer rate per frequency band.

1. Field of the Invention
The present invention relates to a wireless communication system, and more specifically, to an OFDM system for wireless communication in a wireless local area network.
2. Description of the Prior Art
Wireless local area networks (WLANs) are ever increasingly being used in network environments where mobility is of importance. Orthogonal frequency division multiplexing (OFDM) is a well-known concept used in implementing WLAN hardware. A typical WLAN employing OFDM can achieve a maximum data transfer rate of 54 Mbps per client, which is significantly less than the wire-based LAN capability of between 100 Mbps to 10 Gbps. This 54 Mbps transfer limit for WLANs is a consequence of current technological limitations and regulation, such as that according to IEEE 802.11a or 802.11g for example. For conventional WLANs, the advantage of mobility can be enhanced by an improvement in data rate.
FIG. 1 illustrates a convention WLAN 10 including an access point 12, a first user terminal 14, and a second user terminal 16. The WLAN 10 is very much typical of an IEEE 802.11a or 802.11g implementation. The access point 12 includes four antennas (or antenna pairs) for communicating data with the terminals 14, 16, the first user terminal 14 having a single antenna and the second user terminal 16 having two antennas. In the access point 12, a single antenna is used to communicate with the first user terminal 14, and two antennas are used to communicate with the second user terminal 16 over three frequency bands in total.
FIG. 2 illustrates the frequency band assignment of the WLAN 10 of FIG. 1. As each antenna operates in a distinct frequency band, the first user terminal 14 uses a first frequency band, while the second user terminal 16 uses second and third frequency bands. Thus, in accordance with the above-mentioned 54 Mbps transfer rate limitation, the first user terminal 14 and second user terminal 16 have maximum data rates of 54 Mbps and 108 Mbps respectively. Increasing these data rates can only be facilitated by increasing the number of antennas in the user terminals 14, 16 and consequently increasing the number of available frequency bands. In addition, if the WLAN 10 has only three frequency bands available for use, the access point 12 is encumbered with an extra antenna that cannot be used to communicate with another user terminal.
Frequency band assignments for WLANs are set forth in IEEE standards 802.11a and 802.11g, for example. According to IEEE Std 802.11a-1999, the 5 Ghz band comprises 12 frequency bands for data communication. Similarly, the 2.4 Ghz band of IEEE 802.11g offers three frequency bands. Following these specifications, prior art implementations have been constrained to one band per antenna and the resulting 54 Mbps maximum data rate per band.
Therein lies the main problem with the prior art regarding transfer rate. Specifically, in order to increase the data rate to a given terminal, more antennas and thus more frequency bands (available frequency bands being limited in number) must be employed. This runs counter to the need to free up frequency bands for communication with a larger number of terminals. In short, the prior art suffers from limitations in data rate per frequency band.

Multiple antenna OFDM transceiver and method for transceiving


A manufacturing method of an electronic device, includes the steps of: implanting P (phosphorous) ions into a substrate semiconductor region made of Si or SiGe by using a resist as a mask; ashing the resist while it is heated in a vacuum environment; and taking out the substrate, the substrate being ashing processed so that a temperature of the substrate is equal to or less than 130° C.

1. Field of the Invention
The present invention generally relates to manufacturing methods of electronic devices, and more specifically, to a manufacturing method of an electronic device, the method including a step of removing a resist by ashing after P (phosphorus) ions are implanted.
2. Description of the Related Art
Conventionally and continuously, in a manufacturing process of an electronic device such as a manufacturing process of a semiconductor device or a manufacturing process of a liquid crystal panel or an active substrate of an organic EL panel, an ion implantation method has been used for forming a source/drain region or the like. A photoresist has been used as an ion implantation mask.
After the ion implantation, it is necessary to remove this photoresist mask. Recently, instead of a wet process using removal liquid for removing this photoresist mask, an ashing process using O2 plasma has been used. An example of a related art ashing step is discussed with reference to FIG. 1 and FIG. 2 (See Japanese Laid-Open Patent Application Publication No. 11-097421). Here, FIG. 1 is a first view explaining a related art ashing step. FIG. 2 is a second view explaining a related art ashing step.
Referring to FIG. 1, first, an element isolation region 202 is formed in a p-type silicon substrate 201 so that an element forming region is defined. After that, a phosphorus (P) ion is implanted in a part of the element forming region so that an n-type well region 203 and a boron (B) ion is implanted in another part of the element forming region so that a p-type well region 204 is formed.
Next, after a gate dielectric film 205 is formed by applying a thermal oxidation process, gate electrodes 206 and 207 are formed by forming a polysilicon film on an entire surface and by patterning.
Then, P ions 209 are implanted into the p-type well region 204 in a state where the n-type well region 203 is covered with the resist mask 208, so that an n-type source/drain region 210 is formed.
A deformed layer 211 due to the implantation of the P ion is formed on a surface of the resist mask 208.
Next, cations and electrons are removed from plasma of gas where O2 is the main ingredient and N2, H2, and CF4 are added so that a neutral radical environment 212 is made. In the neutral radical environment 212, an ashing process is applied and thereby the deformed layer 211 and the resist mask 208 are removed.
In a case where the ashing process is implemented at a high temperature so that processing speed is made high, in order to prevent a phenomenon where non-deformed resist pops, a step for removing the deformed layer 211 is implemented at 150° C. of substrate temperature. After the deformed layer 211 is removed, the non-deformed resist mask 208 is removed at 200° C. of the substrate temperature.
Referring to FIG. 2, after the processed substrate is taken out to the atmosphere, a cleaning process using a sulfuric acid water solution is applied to the processed substrate so that ashing residual is removed. After that, B ions are implanted into the n-type well region 203 in a state where the p-type well region 204 is covered with the resist mask 213, and thereby a p-type source/drain region 215 is formed.
Next, cations and electrons are removed from plasma of gas where O2 is the main ingredient and N2, H2, and CF4 are added so that neutral radical environment 217 is made. In the neutral radical environment 217, an ashing process is applied and thereby a deformed layer 216 and the resist mask 213 are removed. As a result of this, a basic part of a CMOS transistor is formed.
In this case, in order to prevent the popping phenomenon, a step for removing the deformed layer 216 is implemented at 150° C. substrate temperature. After the deformed layer 216 is removed, non-deformed resist mask 213 is removed at 200° C. substrate temperature.
On the other hand, a technique where, in order to implement the ashing process at a constant substrate temperature, the ashing process is applied to the deformed layer in O2 plasma including 1% of CF4 and at 180° C. substrate temperature so that the deformed layer is removed, and then the ashing process is applied to a non-deformed resist mask in O2 plasma including 5% N2.
As accompanying making the speed of the semiconductor device high, in order to achieve an increase of the driving electric current and the reduction of a leakage current, implantation of impurities is repeated a considerable number of times. It is necessary to remove the resist used as the ion implantation mask. Hence, as the number of implantations is increased, the number of removals of the resist is increased. This causes an increase of the manufacturing time.
Accordingly, currently, as discussed above, the substrate temperature at the time of removing the resist is equal to or higher than 150° C., and thereby reaction speed is made high and the resist removal time is reduced.
Furthermore, in the ashing device having a load lock room, in a case where a semiconductor wafer processed at high temperature is taken out to the atmosphere via the load lock room, temperature unevenness is generated between a part contacting with a substrate supporting jig such as an arm and a non-contacting part. As a result of this, heat deformation may be generated when the semiconductor wafer is rapidly cooled in the atmosphere so that the semiconductor wafer may be warped. Alternatively, thermal stress may be generated so that breakage or short-circuiting of wiring may occur.
Japanese Laid-Open Patent Application Publication No. 11-345771 discloses a technique where a cooling mechanism is provided at the load lock room, a processed semiconductor wafer is mounted on a wafer mounting stage provided at the load lock room so that uniform heat distribution is maintained, and the temperature of the semiconductor wafer is decreased to a designated temperature.
Japanese Laid-Open Patent Application Publication No. 2001-319885 discloses a technique where the processed wafer is self-cooled by opening the load lock room when the pressure of the load lock room becomes atmospheric pressure or by leading inactive gas into the load lock room when the pressure of the load lock room is changed to atmospheric temperature.
However, the inventor of the present invention found that a Si digging phenomenon occurs in the ashing step after P having a high density of 5×1015 cm−2 is ion-implanted. The Si digging phenomenon is a phenomenon where a P implantation region or a polysilicon layer where P is implanted of the silicon substrate is undesirably etched.
FIG. 3 is a cross-sectional view of a main part after a contact hole is formed. More specifically, FIG. 3 is a sketch of an electron micrograph image and a cross-sectional view in a direction parallel with an extending direction of a gate electrode.
FIG. 3-(A) shows a normal state and FIG. 3-(B) shows an abnormal state. Referring to FIG. 3-(B), a hollow part 226 is formed at a corner of a contact hole 224 of a silicon substrate 221 where P is implanted. Furthermore, a hollow part 227 is formed in a region neighboring the contact hole 224.
Since the hollow part 227 in the region neighboring to the contact hole 224 is generated before the contact hole 224 is formed, a step before the contact hole 224 with the hollow part 226 is formed, namely the ashing step after the P ion implantation region is formed, may be the reason for this situation.
FIG. 4 is a cross-sectional view of a state where a resist used as a mask is removed by ashing after the polysilicon layer for the gate electrode is formed and the P ions are partially implanted in order to form an n channel type FET gate electrode and a gate extraction electrode. FIG. 4 is a sketch of an electron micrograph image.
Referring to FIG. 4, the film thickness of a P implantation part of a polysilicon layer is thinner than a non-implantation part situated at the left end side of FIG. 4. This shows that undesirable etching is generated.
Such a Si digging defect causes an increase on the value of resistance of a diffusion resistance layer or a wiring layer so that a signal delay or decrease of the driving electrical current may happen.
In a case where B ions are implanted as shown in FIG. 5-(A), as compared to the P ion implantation shown in FIG. 5-(B), the Si digging defect shown in FIG. 5-(C) does not occur at all. This situation is applied to a case of another impurity such as As and it is confirmed that this situation is peculiar to P.
FIG. 6 is a view for explaining distribution of the Si digging defects.
FIG. 6-(A) shows a distribution indicated by dots without the Si digging defect, in a case where the wafer is taken to the atmosphere after a long time such as approximately 30 through 60 seconds has passed after the ashing process. The distribution is almost even in the wafer.
FIG. 6-(B) shows distribution showing the Si digging defect in a case where the wafer is taken to the atmosphere after a short time such as approximately 10 seconds passes after the ashing process, by dots. The defect in the case of FIG. 6-(B) is larger than the case of FIG. 6-(A) by the Si digging defects.
Thus, if the time period from the time of the ashing process to the time when the wafer is taken out to the atmosphere is long, the temperature of the wafer is decreased so that it may be difficult to generate the Si digging defects.

Manufacturing method of electronic device with resist ashing


A pneumatic unit for supplying products, such as chocolates or similar, in a single line to a manufacturing machine along a route defined laterally by two walls and at the bottom by a plate through which are formed a number of nozzles for a pressurized pneumatic fluid; the nozzles being arranged in at least two rows symmetrical with the route; and each nozzle in each row being so designed as to emit a jet of pneumatic fluid, at least a first portion of which is directed in a traveling direction towards the manufacturing machine, and a second portion of which is directed transversely in relation to the traveling direction and towards the other row of nozzles.

The present invention relates to a unit for supplying products to a manufacturing machine.
In particular, the present invention relates to a unit for supplying small, compact products, and designed for installation between two manufacturing machines, one of which, located downstream from the supply unit, presents a lower operating speed as compared with the upstream machine.
In the following description, specific reference is made, purely by way of example, to a unit for supplying chocolates and installed between a chocolate manufacturing and wrapping machine.
Chocolate manufacturing systems are known to feature manufacturing machines having a number of outputs, to each of which the chocolates are fed at a first given speed and transferred, via an intermediate supply unit, on to the input conveyor of one or more wrapping machines, the input conveyor of which operates in time with the wrapping members on the wrapping machine and at a second speed lower than said first speed.
The supply unit, usually consisting of a conveyor belt, is normally set to such a speed that the chocolates fed on to it off the manufacturing machine are spaced a given distance apart.
Naturally, if the input conveyor to the wrapping machine is operated at a slower speed than the supply unit, the distance between adjacent chocolates on the input conveyor is shortened. The difference between the two speeds may reach a critical point at which the chocolates on the input conveyor actually contact one another, or an even more critical point at which the continuous stream of chocolates on the input conveyor to the wrapping machine extends as far back as the supply unit conveyor, the sliding belt of which tends to damage the underside of the chocolates. Moreover, the scraps of chocolate so produced may melt in contact with the supply unit belt, thus resulting in frequent stoppages of the entire system for cleaning and maintenance.
To overcome the above drawback, the supply unit may consist of a pneumatic conveyor, for example, of the type described and claimed in Canadian Patent N.903140. In this case, each chocolate could be fed forward on a respective air cushion defined by a number of nozzles formed through a bottom plate on the conveyor and so designed as to emit an a r jet comprising two components, one directed upwards and the other inclined slightly forward in the traveling direction of the products.
When applied to two machines of different capacity, a pneumatic conveyor of the aforementioned type provides for effectively supporting the chocolates as they are fed forward, bu not for supporting them pneumatically in a stationary position over the perforated plate, in the event the difference in the speed of the two machines exceeds said critical value. When stationary, in fact, the chocolates tend to vibrate against one another, thus resulting in damage.

Unit for supplying products to a manufacturing machine


This invention relates to a fixing device with a heat rotatory body heated by a heating source having a surface layer of a silicone rubber; a back-up rotatory body which is in pressure contact with the heated rotatory body; an oil feeding apparatus which feeds silicone oil to the heated rotatory surface; the pair of rotatory bodies performing fixing while conveying the supporting material having unfixed images supported thereon sandwiched therebetween; and the feeding oil being a phenyl type silicone oil and the silicone rubber surface being impregnated with dimethylsilicone oil.

1. Field of the Invention
This invention relates to a fixing device which is used for an image forming device such as copying machine, printer, etc. which fixes unfixed images on a supporting material.
2. Related Background Art
As the fixing device for fixing unfixed images, there has been widely used a hot roller fixing device which uses a heating roller with a heater built therein and a back-up roller in pressure contact with the heating roller.
Such heating roller is of the type using a rubber layer as the release layer and of the type using a release layer, but it is advantageous to use a rubber layer for obtaining high fixability. As such rubber, silicone rubber is generally employed for elastic characteristics and mold releasability.
Also, for prevention of off-set, silicone oil is coated on the surface rubber layer. However, fixing by such an image fixing device has been found to generate the following inconveniences.
That is, silicone oil coated as the release agent on the silicone rubber layer of the fixing roller is transferred onto toner and transfer paper during fixing, thereby effecting fixing of the toner image T onto the transfer paper, but the silicone oil remains on the fixing roller in a considerable amount and will penetrate the silicone rubber with time.
The penetration of silicone oil into the silicone rubber layer is further promoted when the fixing roller is heated, rotated, and when the silicone rubber layer receives stress from the pressurizing roller by rotation.
The silicone oil penetrated into the silicone rubber layer promotes pyrolysis of HTV silicone rubber constituting the rubber layer by heat, pressure. If this state continues for a long time, the silicone rubber layer will undergo lowering in hardness as the result of progress of pyrolysis, and further the rubber layer is swelled with the silicone oil, until finally chemical bonding of the HTV silicone rubber is cleaved to effect scission of the rubber. As the result, there occurs the phenomenon that the silicone rubber layer is peeled off from the fixing roller.
Such phenomenon is liable to occur as the temperature is higher, particularly at the silicone rubber layer near the core metal made of aluminum. This may be considered because decomposition of the rubber proceeds greatly as the temperature is higher. For example, even if the thermal conductivity of the HTV rubber may be made as high as 1.0.times.10.sup.-3 cal/cm.multidot.sec.multidot.deg, the temperature in the vicinity of the core metal which will vary depending on such conditions as outer air temperature, heat content of the heater, rotation of the roller, etc., may sometimes become 200.degree. C. when the surface temperature is 170.degree. C.
This is not limited to HTV silicone rubber, but the same phenomenon also occurs with RTV (room temperature vulcanizabIe type) rubber such as dimethylsilicone rubber or methylvinyl silicone rubber or LTV (low temperature vulcanizable type) silicone rubber.
The phenomenon as described above depends on the use time accompanied with heating of the image fixing device, but the time before generation does not differ greatly, although it may vary to some extent depending on the kind of the rubber constituting the silicone rubber layer, the viscosity of the silicone oil, its coated amount, or the heating time, pressurization conditions, rotational conditions of the fixing roller.
For prevention of silicone rubber with silicone oil, for example, Japanese Patent Publication No. 54-26373 proposes a combination of a silicone rubber and a silicone oil so that the rubber layer will not will swell only a or swelled little by selecting the kind of the silicone rubber constituting the rubber layer of the fixing roller, etc. and the kind of the silicone oil coated.
According to the above proposal, as the silicone oil, those of chloro type, fatty acid modified type, nitrile type or fluoro type are employed, and as the silicone rubber, those of methyl type, methylvinyl type or phenyl type are used. Alternatively, as the silicone oil, those of methyl type, phenyl type, methylhydrogen type, methylphenyl type, dimethylphenyl type, chloro type, fatty acid modified type, nitrile type or fluoro type are used, and as the silicone rubber, those of nitrile type or fluoro type are employed (however, when those of nitrile type or fluoro type are used as the silicone oil, silicone rubbers of the same type are excluded).
According to such combination of silicone oil and silicone rubber as mentioned above, it is stated that swelling of the silicone rubber constituting the rubber layer of the fixing roller, etc. with silicone oil can be prevented.
The following Table 1 is an extraction of a part of the combinations from the above proposal. According to this, when one of methyl type, methylvinyl type, and phenyl type is used as the silicone rubber, and one of methyl type, phenyl type is used as the silicone oil, swelling occurs in the rubber, and therefore such combination is stated to be undesirable.
TABLE 1 ______________________________________ Silicone oil Rubber: Methyl type Phenyl type ______________________________________ Methyl type x x Methylvinyl type x x Phenyl type x x ______________________________________ x: indicating that rubber is swelled
As observed from the aspect of mold releasability, methyl type or methylvinyl type or phenyl type silicone rubber is excellent as the rubber material.
In Japanese Patent Publication No. 54-26373, for methyl type, methylvinyl type silicone rubber, silicone oils of chloro type, fatty acid modified type, nitrile type or fluoro type are mentioned as silicone oils which are not swelled with oils, but these materials have lower heat resistance or can be prepared with difficulty to be expensive, and hence not suitable as the coating oil for heating fixing rollers.
As a coating for the heating fixing rollers, silicone oils of methyl type or phenyl type are suitable from the point of view of heat resistance and bulk productivity, but they are combinations which are swelled with methyl type, methylvinyl type, phenyl type silicone rubbers as described above.

Fixing device having silicone rubber sprayed with phenyl type silicone oil


The present invention provides a powerful and robust classification and prediction tool, methodology, and architecture for supervised learning, particularly applicable to complex datasets where multiple factors determine an outcome and yet many other factors are irrelevant to prediction. Among those features which are relevant to the outcome, they have complicated and influential interactions, though insignificant individual contributions. For example, polygenic diseases may be associated with genetic and environmental risk factors. This new approach allow us consider all risk factors simultaneously, including interactions and combined effects. Our approach has the strength of both binary classification trees and regression. A simple rooted binary tree model is created with each split defined by a linear combination of selected variables. The linear combination is achieved by regression with optimal scoring. The variables are selected using backward shaving. Cross-validation is used to find the level of shrinkage that minimizes errors. Using a selected variable subset to define each split not only increases interpretability, but also enhances the model's predictive power and robustness. The final model deals with cumulative effects and interactions simultaneously.

1. Field of the Invention
This invention relates generally to data mining. More particularly, it relates to a binary tree-structured classification and prediction algorithm and methodology for supervised learning on complex datasets, particularly useful in large-scale studies.
2. Description of the Related Art
In many real-world situations, multiple factors combine to determine outcome. Those factors have complicated and influential interactions, though perhaps small and insignificant individual contributions. Most of these individual contributions are so small that their effects could be masked easily by noise if they were considered only separately. One good example of such a situation is the association between polygenic disease and many genetic and environmental risk factors.
The affected status of an individual with such a polygenic disease is a result of interactions among multiple genes and environmental risk factors such as smoking, social stress, and diet. Asthma, hypertension (high blood pressure), type II diabetes and most cancers are polygenic diseases. They affect many people, yet their pathologies remain largely unknown. Limited knowledge tends to preclude researchers from creating effective screening tests or treatments.
One reason for such limited knowledge of pathologies is because, until now, most research on polygenic diseases focuses on identifying and evaluating effects of individual mutations. Each mutation is studied separately, ignoring the fact that the influence of multiple mutations can play a much larger role than the marginal contribution of any single mutation. The net result is a lack of understanding of complicated gene-gene and gene-environmental interactions that underlie most polygenic diseases. There is a continuing need in the art for a new and robust methodology for complex supervised learning where traditional approaches focusing on studying effects of individual factors have proven to be inadequate.

Binary tree for complex supervised learning

The Board of Trustees of the Leland Stanford Junior University


An infeed conveyor for a packaging machine having a first squeezer conveyor including upper and lower belts spaced to receive workpieces in an end-to-end relationship. Upper speed-up rollers and lower speed-up rollers advance the workpieces further along the path of the first squeezer conveyor. A second conveyor being provided for receiving the workpieces from the speed-up rollers. A third conveyor being positioned above the second conveyor and operating at a lower rate of speed whereby when an upper leading edge of a workpiece engages with the third conveyor, the workpiece is rotated approximately ninety-degrees from its previous orientation. Flight bars rotate with the second conveyor at a rate faster than the second conveyor thereby bunching the workpieces into abutting groups of a predetermined size for entry into a packaging machine.

In the United States, infeed conveyors for rolls of paper products such as bathroom tissue (BRT) and household towel (HHT) have fed the respective rolls or workpieces into a packaging machine in a direction which is axial with respect to the cylindrical rolls of paper. In Europe, the rolls of paper product are typically fed into the packaging machine with the roll moving in a radial direction. The European roll is wrapped with a different style of package and with the seal differently oriented with respect to the surfaces and the advertising material printed on the wrapping film.
In the paper industry, paper products such as BRT and HHT are produced from paper made by paper making machines. The base paper from the paper making machines is wound at the machine output into large rolls commonly referred to as parent rolls. The parent rolls are then transported to a paper converting area where the paper product is unwound from the parent roll and re-wound into a smaller roll commonly known as a log. The diameter of a log is equivalent to the diameter of a finished roll of BRT or HHT. However, a log is typically ten to fifteen feet long. The log is transported to a cutting machine having one or more blades that cut the log at predetermined intervals into the length of roll product that is ultimately sold to the consumer. After being cut, the individual rolls of BRT or HHT are transported by a supply conveyor to a wrapping machine where the rolls are subsequently wrapped.
Because the supply conveyor contains a continuous supply of rolls whose ends abut one another, it is necessary to utilize an infeed conveyor in order to separate each roll of BRT or HHT and group a predetermined number of rolls (if necessary) prior to feeding each roll or each group of rolls into the packaging machine. This is accomplished through the use of an infeed conveyor. Infeed conveyors which are utilized for separating and regrouping rolls of BRT or HHT are well known in the art. See for example U.S. Pat. No. 4,360,098 (Nordstrom). This prior art infeed conveyor receives product rolls or workpieces from the supply conveyor in a direction which is axial with respect to the cylindrical rolls of paper. The rolls are separated and grouped prior to being fed into the packaging machine in the same direction. This infeed conveyor is commonly used in the United States as well as other foreign countries.
The present invention, in addition to separating and grouping the rolls of paper product, rotates or up-ends each roll so that each roll of paper product is fed into the packaging machine with the roll moving in a radial direction. As previously noted, many European wrapping machines require the workpieces conveyed into the wrapping machine to be oriented in this direction. It is an object of this invention to provide an infeed conveyor which can, in addition to separating and grouping rolls of paper product, rotate or up-end rolls of paper product for a packaging machine which requires each roll to have the radial orientation prior to being fed into the packaging machine. It is an object to provide an apparatus for up-ending rolls of paper product that is of a simple design. It is further object to provide such an apparatus that works reliably and does not damage the paper product rolls.
The inventors are aware of no prior art which discloses or teaches this invention. Further objectives and advantages of the invention will become apparent in the descriptions which follow.

Apparatus and method for up-ending workpieces


A monosaccharide compound of formula I as shown in the specification. Processes for the preparation of the compound of formula I and methods of screening for antibacterial or antibiotic compounds involving the compound of formula I.

Since the discovery of penicillin in 1928 the apparent ability of the ever-growing numbers of available antibiotics to treat infections and disease has, until recently, caused a high degree of complacency about the threat of bacterial resistance. This complacency has created a situation where antibiotics are over-prescribed in both hospitals and in the community, and used extensively in animal feeds. The alarming speed with which bacteria have become resistant to microbial agents has meant that there is a very real danger that infections, which were until recently completely controllable, will pose serious threats to human health.
All unicellular bacteria contain a cell wall which is associated with a diverse range of functions, although the major one is that of protecting the cell from lysing under high internal osmotic pressures. The cell wall is composed of peptidoglycan, a rigid mesh of β-1,4-linked carbohydrate polymers covalently cross-linked by peptide chains. The peptidoglycan synthetic pathway is not present in mammalian systems, suggesting that the side-effects associated with such inhibitors could be minimized. Thus the bacterial peptidoglycan biosynthetic pathway presents an opportunity for the development of novel antibacterial agents.
There is a great deal of interest in the substrates of the muramyl pathway and their analogues, and in the synthesis of related compounds that may result in new therapeutics. Tanner and co-workers have recently prepared compounds that inhibit the MurD and MurE enzymes of the muramyl pathway. These non-carbohydrate compounds have the sugar and lactate moieties of a muranic acid-like compound replaced with a five carbon linker unit (Zeng, B., Wong, K. K., Pompliano, D. L., , Reddy, S., and Tanner, M. E., J. Org. Chem. 1998, 63(26), 10081-5; Tanner, M. E., Vaganay, S., van Heijenoort,J., and Blanot, D., J. Org. Chem. 1996, 61(5), 1756-60), and are prepared by standard organic chemistry techniques. They are linear, flexible organic compounds with substituents that resemble those of UDP-MurNAc-pentapeptide (the "Park Nucleotide" (Park, J., J. Biol. Chem. 1952, 194, 877)). One of those compounds in particular was found to be a relatively potent inhibitor of MurE (Zeng, B., Wong, K. K., Pompliano, D. L., Reddy, S., and Tanner, M. E., J. Org. Chem. 1998, 63(26), 10081-5).
In other studies on an analogous phosphinate inhibitor of MurD, it was found that retaining the MurNAc sugar residue, instead of replacing it with a carbon linker unit, increases the potency of the inhibitor by almost two orders of magnitude (Gegnas, L. D., Waddell, S. T., Chabin, R. M., Reddy, S., Wong, K. K., Bioorg. Med. Chem. Lett. 1998, 8, 1643). This suggests that building a library of monosacchatide analogues of the substrates of the muramyl pathway is an attractive proposition for the generation of new therapeutics which target that system.
One approach to the synthesis of such compounds is to make use of biosynthetic techniques, such as that used in preparing labeled versions or analogues of MurNAc from GlcNAc by implementing the MurA and MurB enzymes themselves (Lees, W. J., Benson, T. E., Hogle, J. M., and. Walsh, C. T., Biochemisty 1996, 35(5), 1342-1351).
Chemical methods require protected building blocks, and some well-established chemistry has been implemented, using GlcNAc to yield the benzyl glycoside of N-acetyl-4,6-benzylidenemuramic acid (Jeanloz, R. W., Walker, E., Sinaÿ, P., Carbohydr. Res. 1968, 6, 184). One challenge to the synthesis of such compounds is the alkylation of the C-3 position of the carbohydrate residue. In the natural muramyl system, the MurA and MurB enzymes add what is ultimately a lactate moiety to the C-3 position.
The addition of a lactate moiety at C-3 has been achieved chemically in a process in which the required materials were generated through the intermediate preparation of a nitroalkene sugar (Vega-Perez, et al., Tetrahedron 1999, 55, 9641-9650). An alternative approach is the alkylation of the C-3 hydroxyl with the α-bromide of an appropriately protected propanoic acid to generate the required compound (Iglesias-Guerra, F., Candela, J. I., Bautista, J., Alcudia, F., and Vega-Perez, J. M., Carbobydr. Res. 1999, 316, 71-84).
Having compounds with a lactate moiety, or similar acid, in place at C-3 allowed the addition of amino acids to build the required pentapeptide substituent. This molecule was subsequently converted to the natural substrates for the muramyl enzyme system (Hitchcock, C. N., Eid, J. A., Aikins, M. Z-E., and Blaszczak, L. C., J. Am. Chem. Soc. 1998, 120(8), 1916). In a similar approach the preformed pentapeptide was added as a single unit to yield muramyl products (Ha, S., Chang, E., Lo, M-C., Men, H., Park, P., Ge, M., and Walker, S., J. Am. Chem. Soc. 1999, 121(37), 8415).
Combinatorial chemistry and parallel synthesis have become the methods of choice for the rapid synthesis of a large number of related compounds simultaneously, and this approach has been used to produce libraries of compounds to be screened for biological activity. Sometimes such libraries are focused to test for activity of the compounds so generated towards a particular biological agent or organism, although often large libraries are also prepared in a random fashion. Either way, the intended end result of combinatorial chemistry is the rapid discovery and optimization of leads for the development of new pharmaceuticals.
Despite the obvious advantages of a combinatorial approach to the preparation of compounds for drug discovery, this technique is underexplored in the field of carbohydrate chemistry. This is primarily because of the well-known difficulties associated with the synthesis of carbohydrate compounds. For that reason carbohydrate libraries prepared in the past have tended to be relatively simple. For example, Hindsgaul et al have produced a library of monosaccharide compounds by a combinatorial approach (Ole Hindsgaul, U.S. Pat. No. 5,780,603); however, the variation in the compounds was limited to the glycosidic bond. A glycopeptide library in which mannose residues were decorated with various amino acids has been described, but these were conjugated to the sugar solely through the C-6 position (Tennant-Eyles, R. J., and Fairbanks, A. J., Tetrahedron Asymmetry 1999, 10, 391-401).
Access to greater variation has been attempted by making used of libraries of carbohydrate numetics (Byrgesen, E., Nielsen, J., Willert, M., and Bols, M., Tetrahedron Lett. 1997, 38, 5697-5700 and Lohse, A., Jensen, K. B., and Bols, M., Tetrahedron Lett., 1999, 40, 3033-3036). However, one approach which successfully added greater diversity to monosaccharides was that of Goebel and Ugi (Tetrahedron Lett., 1995, 36(34), 6043-6046) who generated a small library of alkylated glycals by subjecting protected glucals to electrophilic attack and then subsequent reactions. Unfortunately this method is limited by the fact that each starting glucal may give rise to a number of isomeric products.
For these reasons there is particular interest in libraries of aminoglycosides and amino sugars for drug discovery. Some work on such compounds has been published, with Silva and co-workers preparing impressive disaccharide libraries containing glucosamine (Silva, D. J., Wang, H., Allanson, N. M., Jain, R. K., and Sofia, M. J., J. Org. Chem. 1999, 64(16), 5926-5929). However, this library still suffers from the limitation that the variation is limited solely to acylations of the amino group.
More variation, and in fact a three-dimensional diversity, was obtained in the preparation of amino sugars by Sofia and co-workers (Sofia, M. J., Hunter, R., Chan, T. Y., Vaughan, A., Dulina, R., Wang, H., and Gange, D., J. Org. Chem. 1998, 63(9), 2802-2803). This allowed chemical diversity at three combinatorial sites on the sugar residue. Other workers have prepared a library of compounds with four (Wunberg, T., Kallus, C., Opatz, T., Henke, S., Schmidt, W., and Kunz, H., Angew. Chem. Int. Ed. 1998, 37(18), 2503-2505), and five (Kallus, C., Opatz, T., Wunberg, T., Schmidt, W., Henke, S., and Kunz, H., Tetrahedron Lett. 1999, 40, 7783-7786) such sites of functionalization, although these compounds were not amino-sugars.
It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents forms part of the common general knowledge in the art, in Australia or in any other country.
Hitherto, there have been few attempts to synthesize analogues of the muramyl substrates, particularly those which contain modifications at the anomeric position or at the C-2 nitrogen. The natural substrate and all of the muramyl enzyme intermediates contain exclusively the α-glycosidic diphosphate. Our modeling and design studies with the crystal structure of the MurD enzyme suggest that both the α or β anomeric configuration of many of the compounds proposed in this invention can fit into the active site of this enzyme. We believe that this is the first time that β-glycosides which contain no phosphate groups have been prepared as potential inhibitors of the muramyl enzyme system.
Many of the traditional methods of carbohydrate synthesis have proved to be unsuitable to a combinatorial approach, particularly because modern high-throughput synthetic systems require that procedures to be readily automatable.
The documents cited throughout this application are incorporated into this application by reference.

Combinatorial libraries of monosaccharides


A method of forming composite materials includes mixing a first metal precursor with a chelating agent to form a first metal-chelate complex. The first metal-chelate complex is added to a polymer binder having terminating hydroxyl groups to form a polymer binder-first metal-chelate. The polymer binder first metal-chelate complex is mixed with an aluminum precursor. The aluminum precursor decomposes forming aluminum nanoparticles dispersed in a continuous phase material having metallic aluminum cores. At least one of the first metal-chelate complex and the first metal is dissolved in the continuous phase. The aluminum nanoparticles can have a passivating coating layer thereon provided by the polymer binder, or can have a passivating coating layer formed by including an epoxide, alcohol, carboxylic acid, or amine in the adding that forms passivating compound(s) which add further protection that can provide complete protection from oxidation of the metallic aluminum cores by air.

Additives comprising fractions of a percent to several percent of solid propellant mixtures have been considered through the years and are commonly employed in many rocket propellant and explosive compositions. Various additives include burn-rate modifiers (e.g., ferric oxide, metal oxides, and organometallics), curing agents, and plasticizers. In certain cases, additions of small (e.g., <5% by weight) amounts of powdered material to the propellant mixture have been shown to increase or otherwise favorably modify the burn rate. Nanoparticle additives may have an even further influence on the burn rate because of their high surface-to-volume ratios.
Powdered aluminum (metal) is commonly added to solid propellant formulations to increase energy density and specific impulse. Ultrafine or nanoparticulate aluminum has the additional potential to increase burning rates due to its much higher surface-to-volume ratio. However, these materials suffer from difficulties of manufacture, safety hazards, and increasing % aluminum oxide content as the particle size decreases.
Several routes have been developed to produce aluminum nanoparticles, including wire explosion "top-down" methods, and chemical synthesis "bottom-up" methods. Chemical synthesis is advantageous in that no specialized equipment besides standard inert-atmosphere chemical reactors is required, and the bottom-up approach provides the ability to precisely control and tailor the material properties, such as particle size and the passivating oxide layer.
AlH3 (or alane) is a sterically and electronically unsaturated moiety that reacts readily with a wide range of Lewis donors. Amine adducts of alane have emerged as convenient aluminum precursors due to the ability of these compounds to decompose to metallic aluminum in the presence of an organometallic titanium catalyst, including at room temperature. Several studies have investigated the use of different solvents, catalysts, temperatures, and organic/inorganic passivating agents. However, this reaction has proven difficult to control due to the fast reaction kinetics and sensitivity to precise reaction conditions. Additionally, these procedures produce agglomerates of aluminum nanoparticles, which precipitate from solution as powders. Besides being a safety hazard, these aluminum powders are difficult to effectively disperse in the polymer binder of the propellant. The aluminum particle agglomeration reduces the ultimate potential of nano-aluminum to provide large increases in propellant burning rates.

Compositions having aluminum particles dispersed in a continuous phase

University of Central Florida Research Foundation, Inc.


A spin transistor comprises a semiconductor substrate part having a lower cladding layer, a channel layer and an upper cladding layer sequentially stacked therein, a ferromagnetic source and drain on the substrate part, and a gate on the substrate part to control spins of electrons passing through the channel layer. The lower cladding layer comprises a first lower cladding layer and a second lower cladding layer having a higher band gap than that of the first lower cladding layer. The upper cladding layer comprises a first upper cladding layer and a second upper cladding layer having a higher band gap than that of the first upper cladding layer. The source and the drain are buried in an upper surface of the substrate part and extend downwardly to or under the first upper cladding layer.

Recently, a spin transistor such as Spin-FET (field effect transistor) has been spotlighted under active investigation as a new concept transistor. A conventional semiconductor-based transistor (for example, MOSFET) controls charges in the semiconductor by use of an electric field, whereas the spin transistor simultaneously controls both charges and spins by use of spin-polarized charges. Today's investigations try to apply the spin transistor to switching devices or logic circuits through control of the spin-polarized charges. Capability of the spin transistor depends on efficiency of injecting spin-polarized electrons from a ferromagnet to a semiconductor without noise. Various investigations have been undertaken in relation to semiconductor materials or metallic materials to improve a spin injection technique.
Currently, MOSFET, one of the most important elements of a semiconductor device, is confronted with problems including difficulty in additional reduction of power and area, and a physical limit of an oxide film thereof. As one of approaches to overcome these problems, devices capable of controlling precession of the spins with voltage have been variously investigated since they were suggested in 1990's. Among these devices, the spin transistor comprises a source, a drain, and a channel to connect the source and the drain. The channel of the spin transistor can be a quantum well layer of high electron mobility, particularly a two-dimensional electron gas (2-DEG) layer. Such a spin transistor is a Datta-Das Spin FET (see "Applied Physics Letter," Vol. 56, p. 665, 1990), and a spin transistor disclosed in U.S. Pat. No. 5,654,566 entitled "Magnetic spin injection field effect transistor and method of operation." Meanwhile, an investigation related to spin injection from the ferromagnet into two-dimensional electron gas layer required to realize the spin transistor is reported by Hammer, et al. (see "Physical Review Letters," Vol. 88, p. 066806, 2002). According to this investigation, the spin transistor has problems of substantial noise and very low injection efficiency. The high noise and very low injection efficiency is mainly caused by mismatch of conductivity between the metallic ferromagnet and the semiconductor, and by noise from a non-uniform junction therebetween.
FIGS. 1(a) and 1(b) are a top view and a cross-sectional view of a conventional spin transistor. Referring to FIGS. 1(a) and 1(b), a spin transistor 50 comprises a substrate part 10, a ferromagnetic source and drain 13 and 14 on the substrate part 10, and a gate 17. The gate 17 is insulated from the source 13, drain 14 and substrate part 10 by a gate oxide. The substrate part 10 is formed of a semiconductor material, and comprises a channel layer 7 which constitutes a two-dimensional electron gas layer. Spins of electrons injected from the source 13 into the channel layer 7 are controlled via a gate voltage. The electron spins reaching the drain 14 have a direction parallel or anti-parallel to a magnetization direction of the drain 14 so that resistance of the spin transistor is controlled.
FIG. 2 is across-sectional view taken along line AB of FIG. 1. Referring to FIG. 2, the substrate part 10 comprises a buffer layer 2, a carrier supply layer 4, a lower cladding layer 5, the channel layer 7, an upper cladding layer 5′, and a capping layer 6 sequentially stacked on a semi-insulating InP substrate 1. The channel layer 7 is constituted by an InAs quantum well layer. The lower cladding layer 5 comprises InGaAs and InAlAs layers 5a and 5b, and the upper cladding layer 5′ comprises InAlAs and InGaAs layers 5b′ and 5a′. Thus, both of the upper and lower cladding layers 5′ and 5 have a double cladding structure which has different energy band gaps. FIG. 2 shows an example of materials used for the respective layers.
FIG. 3 shows an energy-band structure at a junction between the source or drain 13 or 14 and the substrate part 10 in the spin transistor of FIG. 1. Referring to FIG. 3, the InGaAs 5a or 5a′ and the InAlAs 5b or 5b′ serve as energy barriers to constrain electrons within the InAs channel layer 7. In order to allow the spin electrons to be injected from the ferromagnetic source 13 into the channel layer 7, it is necessary for the spin electrons to surmount the energy barriers, that is, 5a′ and 5b′. If the channel layer is in direct contact with the ferromagnet (source) without the energy barriers, injected polarization is lowered due to influence of minor spins and back-scattering. For this reason, the energy barrier is introduced between the layers. In addition, it is necessary to form a cladding barrier surrounding the channel for easy achievement of the Rashba effect through gate control.
However, the energy barriers 5a′ and 5b′ of the double cladding structure cause an increase in contact resistance. Accordingly, the transistor suffers from deterioration in signal sensitivity, increase in power consumption, and reduction in signal-to-noise ratio. As a result, it is difficult to stably obtain clear signals from the spin transistor 50.

Korea Institute of Science and Technology


The present invention provides for a system and method for easily, quickly and reliably attaching a sound suppressor or other auxiliary device to the muzzle end of a firearm barrel, and for easily and quickly removing such device therefrom. Moreover, the invention will allow any suppressor—threaded or unthreaded—to quickly, easily and reliably attach to a firearm utilizing a dual part system. The dual part system comprises a barrel adapter having the ability to attach directly to a non-threaded suppressor or a quick disconnect suppressor, or connect to a threaded suppressor utilizing a supplemental coupling adapter which connects to existing threaded suppressors.

The present invention relates to firearms, and more particularly to a system and method for securing auxiliary attachments, such as a sound suppressor, to the muzzle of a firearm.
A sound suppressor is a device attached to or part of the barrel of a firearm which reduces the amount of noise and visible muzzle flash generated by firing. Suppressors are typically constructed of a metal cylinder with internal mechanisms to reduce the sound of firing by slowing the escaping propellant gas and sometimes by reducing the velocity of the bullet.
Apart from integral suppressors which are integrated as a part of the firearm's barrel, most suppressors have a "female" threaded end, which attaches to "male" threads cut into the exterior of the barrel.
Alternatively, firearms often utilize "quick-detach" suppressors which use coarser than normal threads and are installed over an existing muzzle device such as a flash suppressor and may include a secondary locking mechanism to allow the shooter to quickly and safely add or remove a sound suppressor based on individual needs.
Various systems are known in the firearms art for attaching a sound suppressor to a firearm. There nevertheless exists a need for improving such systems, particularly for increasing the ease by which a user may attach or detach a firearm with a sound suppressor, whether the sound suppressor is threaded or not threaded, while at the same time effecting a reliable securement there between capable of withstanding the vibrations incidental to the firing of such firearms as automatic rifles used by military personnel, and without adversely affecting accuracy or consistency of high precision firearms.

System and method for attaching a sound suppressor to a firearm


The present disclosure provides for pheromonal compositions and methods of using the compositions for stimulating early onset of estrus in a peri-pubertal suid and methods of improving performance of the peri-pubertal female suid. The composition may comprise at least one steroid hormone and a heterocyclic aromatic compound. The method comprises administering the pheromone composition to the suid for a period of time.

The biology of swine growth and development imposes constraints on herd management, facilities design, and productivity. The boundaries of some biological parameters are relatively inflexible, but for others, the boundaries are highly influenced by genetics or the environment. Age at puberty is one of the flexible parameters. The time at which first estrus occurs in females is usually at 6-8 months of age, but depends on breed, environment and season of the year. Further, timing of first estrus in peri-pubertal gilts can also depend on exposure to male odors, usually provided in the form of a live, adult boar. For instance, if peri-pubertal pigs are kept in a conventional finishing barn without exposure to adult male pigs and their odor, peri-pubertal females may not have their first fertile estrus for many months (8 months of age or later).
As the aim of efficient pig production is to maximize growth and turnaround of animals, accelerating the onset of puberty in peri-pubertal gilts would significantly improve productivity. However, using the current methods of the industry to induce estrus (exposing peri-pubertal suids to boars) and then identifying first estrus is time consuming and labor intensive. For instance, peri-pubertal pig may have to be exposed to a boar multiple times to successfully induce estrus. Further, handling animals during this phase of pig farming can even be dangerous to the humans that work with them.
Pheromone signals are known to play a major role in mammalian reproduction and behavior. Scientific literature points to salivary steroid molecules androstenone and androstenol as the recognized boar pheromone that is responsible for inducing reproduction in the female pig (see Melrose et al., "Androgen steroids associated with boar odour as an aid to the detection of oestrous in pig artificial insemination", The British Veterinary Journal, 127, 497-502 (1971); see also Perry et al., "Pig courtship behaviour: pheromonal property of androstene steroids in male submaxillary secretion", Animal Production, 31, 191-199 (1980)). Products such as Boarmate™ (ITSI, Canada), which contain androstenone as the sole active, have long been sold on the market to detect female pigs in heat and have been used to save time and money when breeding pigs. Further, compositions for the inducement of reproductive behavior in adult female suids have been described (U.S. Pat. No. 9,480,689). However, there are currently no known methods that may be used to accelerate the onset of puberty in peri-pubertal gilts.
Accordingly, to increase productivity in pig farming, there is a need within the industry for methods of stimulating early onset of estrus, reducing labor, and improving human safety when peri-pubertal gilts are managed.

This patent is subject to a terminal disclaimer.

Pheromone compositions for stimulating early onset of estrus and reducing labor needs in breeding peri-pubertal suids and methods of use


In order to promote the formation of the C2 state during manufacturing of a ferroelectric liquid crystal display comprising a cell including a layer of chiral smectic ferroelectric liquid crystal material contained between two substrates. The manufacturing method includes the steps of (a) heating the liquid crystal material and (b) whilst allowing the liquid crystal material to cool from an elevated temperature, which is close to the phase transition temperature to the chiral smectic phase, allowing pressure to the liquid crystal material within the cell by means of rollers in such a manner as to produce mass flow of liquid crystal material within the cell so that the liquid crystal material preferentially adopts the C2 state on cooling to the device operating temperature. This avoids formation of both the C1 and C2 states in the manufactured display which would otherwise result in a patchy appearance, and allows faster switching at lower voltages.

Liquid crystal devices incorporating a ferroelectric smectic liquid crystal material (FLCDs) are particularly suitable for use in displays and shutters in which their fast switching times and memory characteristics are of advantage. A conventional FLCD cell comprises a layer of ferroelectric smectic liquid crystal material contained between two parallel glass substrates, electrode structures being typically provided on the inside facing surfaces of the glass substrates in the form of row and column electrode tracks which cross one another to form an addressable matrix array. Prior to assembly of the substrates and filling of the cell with liquid crystal material, the inner surface of one or both substrates is treated to impart a preferred surface alignment direction and preferably a surface pretilt to the contacting molecules of the liquid crystal material layer.
The switching behavior of the liquid crystal molecules is dependent on the arrangement of the molecules in microlayers which, in the case of chiral smectic material, extend transversely of the substrates and adopt a chevron geometry having two possible states, C1 and C2, ad disclosed in J Kambe et al, Ferroelectric (1991), vol. 114, pp 3. Both C1 and C2 states can form as the material cools down from an isotropic phase to the chiral smectic phase during manufacture, and the boundaries between these two states may be seen as a zigzag defect. When used in a display device, material incorporating both the C1 and the C2 states can appear patchy, and it is therefore preferred that the material should be in one state for a practical device. The C2 state is preferred as it allows faster switching at lower voltages.
FLCD's are typically produced by assembling together the two glass substrates after they have been provided with the required electrode structures and appropriate surface treatment, typically involving spinning on a thin polymer alignment layer which is then rubbed to impart a preferred surface alignment direction, spacers being provided to space the two substrates apart by a small amount, typically in the range of 0.5 .mu.m to 50 .mu.m. The cell may then be filled by placing it above a bath of liquid crystal material, which is heated to a temperature at which it is in the isotropic phase, so that the bottom edges of the substrates are in contact with the material within the bath, and by then applying a vacuum so as to slowly draw the liquid crystal material upwardly between the substrates by capillary action. Alternatively the cell may be filled by injection of the liquid crystal material between the substrates. After filling of the cell, which may take a number of hours, the heat is removed and the cell is cooled down very slowly so that the liquid crystal material passes from the isotropic phase through the cholesteric and smectic A phases to the chiral smectic phase (usually the chiral smectic C phase) as the material cools (one or more of these phases may be omitted in certain materials). It is known to impart a pretilt by means of the alignment layer which favours the C2 state on cooling of the material. High values of pretilt tend to favour the C1 state, whereas low or medium values of pretilt tend to favour the C2 state. The relevant criteria are described in more detail in J C Jones, M J Towler, J R Hughes. "Fast, high-contrast ferroelectric liquid crystal displays and the role of dielectric biaxially". Displays (1993). vol. 14, no. 2, pp 86. However it can be difficult to obtain large areas of the C2 state in certain materials.

Promotion of C2 state in ferroelectric liquid crystal devices

The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland


A cooling system is provided for enclosed volumes having payloads of electronic or other equipment that are susceptible to failures when overheated. One particularly useful application of the present invention is in a cooling system for a turreted gimbaled system (i.e. a gimbal) that includes electronic and optical equipment typically used for surveillance, but many other applications will become apparent to those skilled in the art after being taught by the present disclosure. According to one aspect of the invention, a cooling system includes a pair of reciprocal openings between a gimbal sphere and yoke allowing for passage of air therethrough and a pair of fans for circulating the air between the sphere and yoke, thereby expanding the surface area available for heated air from the interior to conduct into the exterior air. In another example, a heat exchanger is provided in the yoke to allow further cooling of the circulated air. In another example, a heat pipe is provided in the yoke to allow heat to be transferred to the heat exchanger.

It is well known that heat can be a problem, and that overheating can lead to failures of components such as electronics. This is particularly true with enclosed, largely airtight payloads filled with electronics and other gear.
As shown in FIG. 1, enclosed volume 100 is bounded by a shell that has an exterior skin 108 and interior skin 106. Within the enclosed volume is a hot spot 102 and interior air 104. Conventional cooling techniques typically rely on air transfer (e.g. fans) to cool down hot spots. But air is a poor transfer medium, and such cooling techniques are sometimes insufficient. Meanwhile, if the enclosed volume 100 is in an environment (e.g. airborne at high altitudes) where the exterior air 110 is much colder than the interior air, the much colder exterior air 110 could be used to cool down the hot spot. This however, requires an efficient means of transferring heat from hot spot 102 to interior air 104 to interior skin 106 to exterior skin 108 to exterior air 110.
One particular problem in this transfer is that interior air 104 is a poor heat conductor. Rather than directing heat from hot spot 102 efficiently to the interior skin 106, where it can be then transferred to exterior air 110, heat tends to disperse throughout all available interior air 104. Not only does this lead to unreliable cooling of the hot spot, but the interior air 104 also heats up, further leading to its inability to provide cooling to the hot spot 102 and other components in the interior of the enclosed volume.
Accordingly, it would be desirable if there was a system for more reliably cooling the interior of an enclosed volume, including the cooling of hot spots in the volume such as electronics equipment.

Cooling system and method for enclosed volume


The present disclosure relates to an organic electroluminescent compound and an organic electroluminescent device comprising the same. An organic electroluminescent device having a low driving voltage, a high luminous efficiency and/or excellent color coordinates can be provided by comprising the organic electroluminescent compound according to the present disclosure.

An electroluminescent (EL) device is a self-light-emitting device with the advantages of providing a wider viewing angle, a greater contrast ratio, and a faster response time. The first organic EL device was developed by Eastman Kodak, by using small aromatic diamine molecules and aluminum complexes as materials for forming a light-emitting layer (see Appl. Phys. Lett. 51, 913, 1987).
An organic EL device (OLED) changes electric energy into light by the injection of a charge into an organic light-emitting material, and commonly comprises an anode, a cathode, and an organic layer formed between the two electrodes. The organic layer of the organic EL device may be composed of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer (containing host and dopant materials), an electron buffer layer, a hole blocking layer, an electron transport layer, an electron injection layer, etc.; the materials used in the organic layer can be classified into a hole injection material, a hole transport material, an electron blocking material, a light-emitting material, an electron buffer material, a hole blocking material, an electron transport material, an electron injection material, etc., depending on functions. In the organic EL device, holes from an anode and electrons from a cathode are injected into a light-emitting layer by electric voltage, and an exciton having high energy is produced by the recombination of the holes and electrons. The organic light-emitting compound moves into an excited state by the energy and emits light from energy when the organic light-emitting compound returns to the ground state from the excited state.
Research is underway to improve the performance of an organic electroluminescent device by using a material suitable for each layer in the organic electroluminescent device.
For example, an electron transport material actively transports electrons from a cathode to a light-emitting layer and inhibits transport of holes which are not recombined in the light-emitting layer to increase recombination opportunity of holes and electrons in the light-emitting layer. Thus, electron-affinitive materials are used as an electron transport material. Organic metal complexes having light-emitting function such as Alq3 have been conventionally used as an electron transport material. However, Alq3 also has a limitation in providing an organic electroluminescent device having sufficiently satisfactory performance, thus, there is a demand for an electron transport material having improved performance capable of replacing Alq3. Therefore, new electron transport materials have been required, which do not have the above problems, are highly electron-affinitive, and quickly transport electrons in organic EL devices to provide organic EL devices having high luminous efficiency.
Further, the electron buffer layer is a layer for solving the problem of a change in luminance caused by the change of a current characteristic of the device when exposed to a high temperature during a process of producing a panel. In order to obtain a similar current characteristic and a stability to high temperature compared to a device without an electron buffering layer, the characteristic of the compound comprised in the electron buffer layer is important.
U.S. Pat. No. 6,849,348 B2, U.S. Pat. No. 7,285,341 B2, U.S. Pat. No. 8,993,128 B2, and KR 2016-0052399 A disclose indenoquinoline derivatives as compounds for an organic electroluminescent device. However, the compounds disclosed in the above documents do not disclose the compounds of the present disclosure in view of specific compound structure including the kinds and position of the substituent.

Organic electroluminescent compound and organic electroluminescent device comprising the same

Rohm and Haas Electronic Materials Korea Ltd.


A depilator has a casing, a row of tweezers, and a skin tensioner which is driven independently from the skin tensioner. When using the depilator, the user grips the casing of the depilator. The skin tensioner swings back and forth between a home position and a tensioning position, thereby applying an appropriate tension to the skin during the depilation.. The pain caused by plucking hair is reduced. The driving load of the skin tensioner can also be reduced.

1. Field of the Invention
The present invention relates to depilators for removing unwanted hairs for cosmetic and aesthetic purposes.
2. Description of the Related Arts
Many types of cosmetic/aesthetic depilators are known. For example, Japanese Patent Application Laid-open No. 7-313243 discloses a depilator which has a rotational skin tensioner along the periphery of the depilator. This depilator removes unwanted hairs, while tensioning the skin using the rotating skin tensioner, thereby reducing stimulus to the skin. In particular, this arrangement can effectively relieve pain caused when the skin is pulled up due to the resistance of the hair.
However, the conventional depilators have some drawbacks. Because the skin tensioner is continuously rotating on the skin surface during use, the skin tensioner's driving load is large and, in addition, relatively long hair is caught in the rotating device.


A record carrier has a spiral track in which sound and/or video information is stored formed on a transparent substrate and covered by a reflecting layer of metallic material for reflecting a reading beam. The metallic layer does not extend to the inner and/or the outer edge portion of the substrate and is covered by a protective layer. The protective layer is extended to the inner and/or the outer edge portion of the substrate so as to seal the metallic layer for preventing oxidation thereof.

1. Field of the Invention
This invention relates to optically readable record carriers on which information is stored in an optically readable structure.
2. Description of the Prior Art
Such a record carrier, in the shape for example of a disc, can be read optically by focussing a reading beam of radiation such as visible or infrared light onto the optical structure, and moving the radiation spot thus formed and a spiral information track relative to each other. This results in the reading beam being modulated in accordance with the sequence of areas and intermediate areas in the spiral information track. The modulated reading beam is then converted by a radiation-sensitive detector into an electrical signal from which for example audio and/or video information can be derived.
Such a record carrier conventionally comprises a transparent substrate having pits or bumps forming the spiral information track thereon, a metallic layer covering the surface of the substrate including the pits or bumps, and a protective layer covering the metallic layer for protecting the metallic layer. In this case, a reading beam is projected from underneath the substrate onto the spiral information track, where it is reflected by the metallic layer. More particularly, the metallic layer forming the reflective layer is formed over the whole of that surface of the substrate on which information is stored. In practice, aluminum is used for the metallic layer which is formed or applied by a normal evaporation or sputtering process. Then, a protective material, such as a resin curable by ultra-violet light (hereinafter referred to a U.V. resin), is applied onto the metallic layer and cured by ultra-violet light, in order to protect the metallic layer from scratches, abrasion and wear.
However, since the metallic layer extends to the outer-most and inner-most portions of the substrate, that is the edge portions of the record carrier, the edge portions of the metallic layer are exposed to air, so that it becomes oxidized, with a consequent tendency to strip off from the substrate and/or the protective layer. Also, if such stripping-off occurs, air further invades the stripped-off region, so that the oxidation and the stripping-off progress further across the record carrier. Of course, if a clear metallic layer is not maintained on the information area, correct reproduction is not obtained by the reading beam. Moreover, aluminum does not have very good compatibility with the resin and this tends to increase the stripping-off.
The conventional record carrier generally has a paper label on which information such as music titles and details of artists and composers is printed. If such a paper label is attached to the protective layer by adhesive material, the label stresses the substrate, so that there is a tendency to warp the record carrier.


Compactable power generation arrays are provided. The compactable power generation arrays may include a structural substrate body having an array of solar concentrators configured to receive and re-direct solar radiation onto a plurality of photovoltaic (PV) cells. In many other embodiments the PV cells may be disposed upon a back surface of each of the solar concentrators such that an adjacent solar concentrator is configured to re-direct solar radiation onto the PV cell disposed on the back surface of the adjacent solar concentrator.

Space-based solar structures describe physical structures capable of solar energy collection while deployed in a space environment. Space-based solar structures are designed to collect solar energy and convert it into electric energy for a variety of uses including powering the structure itself to wirelessly transmitting the energy to another structure either space-based or ground based. Space-based solar structures can include a variety of structures ranging from a single satellite to an array of satellites.
A general limitation of space-based solar structures is the size required to generate a commercially viable energy source. Large arrays are necessary in order to produce a commercially viable amount of energy. The current cost to launch a space-based solar structure is close to $20,000 per kilogram of material. While those costs have the potential to decrease with the advancement of rocket system technology, the cost for placing objects in space are likely to remain a limiting factor for constructing large scale space-based structures for the foreseeable future. The cost limitation for launching large scale structures into space requires space-based systems to reduce volume and weight as much as possible.
The general limitation of commercial viability has driven development in space-based structures that are more compactable and light weight. In contrast, ground based solar structures do not face the same limitations. Ground based solar structures do not have the added cost of launching into space and therefore do not have to be compactable or light weight. Rather, terrestrial-based systems are generally rigid and bulky. Furthermore terrestrial-based systems can and must be expanded to be large scale in order to be efficient. Finally, without the added cost of launching into space, terrestrial systems can be expanded over time without much added expense.


A system and method for test generation for system level verification using parallel algorithms are provided. The present invention generates test patterns for system level tests by exploiting the scalability of parallel algorithms while allowing for data set coloring and expected result checking. Based on the characteristics of the system being tested an iterative parallel algorithm is selected from a plurality of possible parallel algorithms. The selected parallel algorithm is then separated into separate program statements for execution by a plurality of processors. A serial version of the selected algorithm is executed to generate a set of expected results. The devised parallel version of the selected algorithm is then run to generate a set of test result data which is compared to the set of expected results. If the two sets of data match, it is determined that the system is operating correctly.

1. Technical Field
The present invention relates generally to an improved data processing system and method. In particular, the present invention provides a system and method for test generation for system level verification using parallel algorithms.
2. Description of Related Art
While known mechanisms for validating the operation of individual devices tend to provide adequate results for validating these devices, traditional approaches to system level validation suffer from a number of problems. These problems stem from the fact that traditional approaches to system level validation are basically attempts to extend the individual unit validation approaches to a system level. These traditional approaches of extending individual unit level validation methods to a system level in which many different units are operating together and often simultaneously, do not provide adequate results for determining valid operation of the system as a whole because they do not scale in a tractable algorithmic fashion.
For example, many researchers today are refining techniques to generate test vectors based on constraint solving abstract models of real systems. This approach derives from processor validation where the models can be expanded to include as much architecture detail as a user can tolerate to provide in the time available. This technology derives interesting scenarios by solving constraints over state variables. However, the required amount of system information that is necessary for this approach grows exponentially over the state space and becomes more complex. Thus, these algorithms do not scale, creating streams of long test vectors that attack state space deep in the design and become non-tractable. Alternatively, in an effort to minimize this complexity and exponential growth, these algorithms may become too abstract to adequately exercise system level transactions in a scenario where the processors are doing work that presents the possibility for contention.
An alternative approach also often employed for system validation is to debug the system using application software. The signature of the debug tests can be used for performance determinations. However, debugging requires intimate knowledge of the behavior of the system and the software operating in the system. While this can be obtained with reference models, the data patterns can not be tailored for quick debug.

System and method for test generation for system level verification using parallel algorithms

International Business Machines Corporation