A semiconductor apparatus according to embodiments of the invention can include a first semiconductor device made of silicon, the first semiconductor devices being arranged collectively, whereby to form a first device group, and a second semiconductor device made of silicon carbide, the second semiconductor devices being arranged collectively, whereby to form a second device group. The apparatus can also include a wiring conductor connecting the first semiconductor device and the second semiconductor device, a cooling fin base comprising a projection formed thereon, whereby to dissipate heat generated from the first and second semiconductor devices, and the projections arranged under the second device group being spaced apart from each other more widely than the projections arranged under the first device group.

FIG. 10 is a circuit diagram of a three-phase inverter. The three-phase inverter circuit shown in FIG. 10 includes an upper arm; a lower arm; a U-terminal, a V-terminal, and a W-terminal connected to the respective connection points of the upper and lower arms; a P-terminal connected to the high-potential side of the upper arm; an N-terminal connected to the low-potential side of the lower arm; semiconductor switching devices such as IGBT's constituting the upper and lower arms; and free-wheeling diodes (hereinafter referred to as "FWD's") connected in opposite parallel to the respective IGBT's.
FIG. 11(a) is the top plan view of a conventional semiconductor apparatus. FIG. 11(b) is the cross sectional view along the single-dotted chain line X-X in FIG. 11(a). FIG. 11(c) is the bottom plan view of the conventional semiconductor apparatus showing the base including fins formed thereon.
Referring now to these drawings, conventional semiconductor apparatus 600 is a power semiconductor module that constitutes the three-phase inverter circuit shown in FIG. 10 thereon.
In the following descriptions, Si-IGBT chip 54 is a silicon insulated-gate bipolar transistor chip and SiC-Di chip 55 is an FWD chip made of a silicon carbide Schottky barrier diode (SBD).
The three-phase inverter circuit includes the U-phase, V-phase and W-phase. Since the chip arrangements in these phases are the same, the chip arrangement in the U-phase is described exemplary.
In semiconductor apparatus 600, electrically conductive film 52c of insulated substrate 52 is fixed onto base 51. Insulated substrate 52 includes electrically conductive patterns 52a and 53a formed thereon. Base 51 includes fins 51a formed thereon. The collector of Si-IGBT chip 54 on the upper arm and the cathode of SiC-Di chip 55 on the upper arm are fixed onto electrically conductive pattern 52a. The collector of Si-IGBT chip 54 on the lower arm and the cathode of SiC-Di chip 55 on the lower arm are fixed onto electrically conductive pattern 53a.
The emitter of Si-IGBT chip 54 on the upper arm and the cathode of SiC-Di chip 55 on the upper arm are connected to each other with wiring bar 56. The emitter of Si-IGBT chip 54 on the lower arm and the cathode of SiC-Di chip 55 on the lower arm are connected to N-terminal bar 59. Electrically conductive pattern 52a is connected to P-terminal bar 58. The cathode of SiC-Di chip 55 on the upper arm and electrically conductive pattern 53a are connected to each other with wiring bar 57. Wiring bar 57 is connected to U-terminal bar 57a.
Since the chip arrangements in the V- and W-phases are the same with the chip arrangement in the U-phase, the duplicated descriptions on the chip arrangements in the V- and W-phases are omitted for the sake of simplicity.
U-terminal bar 57a, V-terminal bar 57b, and W-terminal bar 57c are connected to a not-shown load. P-terminal bar 58 and N-terminal bar 59 are connected to a not-shown power supply. The connection points of these terminals are exposed from a not-shown resin case.
On each of three insulated substrates 52, two Si-IGBT chips 54 and two SiC-Di chips 55 constituting the upper and lower arms are mounted and arranged in adjacent to each other. By arranging Si-IGBT chips 54 and SiC-Di chips 55 constituting the upper and lower arms collectively on the same insulated substrate 52, the heat values generated by operating Si-IGBT chips 54 and SiC-Di chips 55 on insulated substrates 52 are set to be the same.
Therefore, the generated heat values on insulated substrates 52 are equalized, fins 51a constituting base 51 are arranged with an equal spacing. Fin 51a is a plate-shaped tooth (rectangular parallelepiped). The spaces between fins 51a under insulated substrates 52 are equal. The spaces between fins 51a are set to be narrow for dissipating the heat generated by chips 54 and 55 effectively.
FIG. 12(a) is a cross sectional view describing the way of cooling semiconductor apparatus 600. FIG. 12(b) is a bottom plan view describing the way of cooling semiconductor apparatus 600.
Referring now to these drawings, cover 60 is set on base 51 including fins formed thereon. Although not illustrated, cover 60 includes an inlet for making coolant 61 flow in and an outlet for making coolant 61 flow out. Coolant 61 made to flow in from the inlet passes through the spaces between fins 51a and flows to the outlet. Coolant 61 flows through the close spaces between fins 51a. For making coolant 61 pass through the spaces between fins 51a, it is necessary to pressurize coolant 61. The pressure necessary to make coolant 61 pass through the spaces between fins 51a (the different pressure between at the inlet and at the outlet) is referred to as the "pressure loss." Usually, coolant 61 is circulated by a not-shown pump.
FIG. 13(a) is a cross sectional view describing the thermal interference caused between the chips in semiconductor apparatus 600. FIG. 13(b) is the cross sectional view along the single-dotted chain line X-X in FIG. 13(a) describing the thermal interference occurred between the chips in semiconductor apparatus 600. FIG. 13(c) is the cross sectional view along the single-dotted chain line Y-Y in FIG. 13(a) describing the thermal interference occurred between the chips in semiconductor apparatus 600.
When the three-phase inverter circuit operates, thermal interference occurs between Si-IGBT chip 54 and SiC-Di chip 55.
Now thermal interference 71 will be described below with reference to FIG. 13(b).
When Si-IGBT chip 54 on the U-phase upper arm is operating but SiC-Di chip 55 on the U-phase lower arm is not, Si-IGBT chip 54 generates heat and the heat generated is transferred from electrically conductive pattern 52a to adjacent electrically conductive pattern 53a through insulator substrate 52b. The transferred heat makes the temperature, which is low, of chip 55 fixed to electrically conductive pattern 53a rise. When SiC-Di chip 55 on the U-phase lower arm is operating but Si-IGBT chip 54 on the U-phase upper arm is not, the Si-IGBT chip 54 temperature, which is low, is raised.
Now, thermal interference 72 will be described below with reference to FIG. 13(c).
Because SiC-Di chip 55 on the U-phase upper arm is not operating, while Si-IGBT chip 54 on the U-phase upper arm is operating, Si-IGBT chip 54 generates heat and the generated heat makes the adjacent SiC-Di chip 55 temperature, which is low, rise via electrically conductive pattern 52a. When SiC-Di chip 55 on the U-phase upper arm is operating but Si-IGBT chip 54 on the U-phase upper arm is not, the Si-IGBT chip 54 temperature, which is low, is raised.
Because thermal interference 71 occurs via insulator substrate 52b and thermal interference 72 via electrically conductive pattern 52a, thermal interference 72 is larger than thermal interference 71. Thermal interference 71a caused through base 51 including fins 51a formed thereon is small, therefore the heat generated is dissipated almost to coolant 61 via fins 51a. The distances M1 and M2 between chips 54 and 56, and the distance M3 between insulated substrates 52 including an electrically conductive pattern formed thereof are several mm.
Thermal interference 72 between Si-IGBT chip 54 and SiC-Di chip 55 occurs through electrically conductive pattern 52a exhibiting a high thermal conductivity and near to the heat sources. Thermal interference 71 between Si-IGBT chip 54 and SiC-Di chip 55 occurs through insulator substrate 52b near to the heat sources and far from the coolant. Therefore, thermal interference 72 and thermal interference 71 caused in conventional semiconductor apparatus 600 are large.
FIG. 14 is a top plan view describing the heat exchanges between the chips via terminal bars in conventional semiconductor apparatus 600.
Thermal interference 65 occurs through wiring bar 56 connecting the Si-IGBT chip 54 emitter and the SiC-Di chip 55 anode on the upper arm. Thermal interference 66 occurs through N-terminal bar 59 connecting the Si-IGBT chip 54 emitter and the SiC-Di chip 55 anode on the lower arm. Thermal interference 67 occurs through wiring bar 57 connecting the Si-IGBT chip 54 anode on the upper arm and electrically conductive pattern 53a on the lower arm.
The distance between the connection point of wiring bar 56 and the Si-IGBT chip 54 emitter on the upper arm and the connection point of wiring bar 56 and the SiC-Di chip 55 anode on the upper arm is designated by N1. The distance between the connection point of N-terminal bar 59 and the Si-IGBT chip 54 emitter on the lower arm and the connection point of N-terminal bar 59 and the SiC-Di chip 55 anode on the lower arm is designated by N2. The distance between the connection point of wiring bar 57 and the Si-IGBT chip 55 anode on the upper arm and the connection point of wiring bar 57 and electrically conductive pattern 53a is designated by N3. Since the distances N1, N2, and N3 are short, from 1 cm to several cm, thermal interference 65, thermal interference 66, and thermal interference 67 are large.
The operable temperature of SiC-Di chip 55 is 250° C. However, the operable temperature of Si-IGBT chip 54 is 175° C. If SiC-Di chip 55 is operated at 250° C., the Si-IGBT chip 54 temperature will exceed 175° C. to the higher side, causing thermal destruction of Si-IGBT chip 54.
Because the operable temperature of the semiconductor apparatus is determined by the operable temperature of Si-IGBT chip 54, it is necessary to restrict the operating temperature of SiC-Di chip 55 to be 175° C. or lower.
Japanese Unexamined Patent Application Publication No. 2009-272482 (also referred to herein as "Patent Document 1"), discloses a semiconductor apparatus that includes a first laminate structure, a second laminate, and a connection section connecting the first and second laminates electrically to each other. The first laminate structure includes a first heatsink, a first isolation layer, a first electrically conductive layer, and a first semiconductor device (silicon IGBT). The second laminate structure includes a second heatsink, a second isolation layer, a second electrically conductive layer, and a second semiconductor device (SiC diode). The semiconductor apparatus separates the first and second laminate structures from each other such that the first and second laminate structures are thermally insulated from each other.
In the semiconductor apparatus disclosed in the Patent document 1, the Si-IGBT chips constituting an upper arm are aligned to form an upper arm Si-IGBT chip group. The SiC-Di chips constituting the upper arm are aligned to form an upper arm SiC-Di chip group. The Si-IGBT chips constituting a lower arm are aligned to form a lower arm Si-IGBT chip group. The SiC-Di chips constituting the lower arm are aligned to form a lower arm SiC-Di chip group. The upper arm Si-IGBT chip group and the upper arm SiC-Di chip group are arranged alternately. The lower arm Si-IGBT chip group and the lower arm SiC-Di chip group are arranged alternately. The coolant flows through the Si-IGBT chip group and, then, through the SiC-Di chip group. In other words, the semiconductor apparatus disclosed in the Patent Document 1 includes two coolant paths for cooling the chips constituting the upper arm and for cooling the chips constituting the lower arm. The coolant path is long.
Since the operable temperature of Si-IGBT chip 54 is 175° C. as described above, it is impossible to operate SiC-Di chip 55 at the operable temperature thereof, that is 250° C. Since Si-IGBT chip 54 and SiC-Di chip 55 are arranged in close proximity to each other, the thermal interference between Si-IGBT chip 54 and SiC-Di chip 55 is large. Therefore, for improving the cooling efficiency, it is necessary to set the distance between fins 51a to be short (to arrange fins 51a more closely). However, the close arrangement of fins 51a increases the pressure loss of coolant 61, further increasing the size of the pump for circulating the coolant. As a result, the manufacturing costs of the entire inverter system soar.
In the Patent Document 1, the cooling structure in which Si-IGBT chip is positioned, is the same with the cooling structure in which SiC-Di chip is positioned. Moreover, the Si-IGBT chip group and the SiC-Di chip group are arranged in adjacent to each other. Therefore, it is impossible to raise the operating temperature of the SiC-Di chip to the operable temperature thereof. Although a thermal insulation structure is formed between the Si-IGBT chip group and the SiC-Di chip group, thermal interference occurs between the Si-IGBT chip and the SiC-Di chip because of a connecting wire that is not shown.
Two coolant paths are formed in the cooling structure. Since the coolant paths are complicated and long, the coolant pressure loss is large. Therefore, the pump for circulating the coolant is large inevitably. As a result, the manufacturing costs of the entire inverter system soar.
In view of the foregoing, it would be desirable to obviate or lessen the problems described above. It would be also desirable to provide a semiconductor apparatus, including a Si semiconductor device, a SiC semiconductor device, and a base including fins formed thereon, that facilitates operating the semiconductor devices at the respective operating temperatures and reducing the pressure loss of the coolant.

Semiconductor apparatus including cooling base with projections


Devices and systems comprising driver circuits are disclosed for MOSFET driven, normally-on gallium nitride (GaN) power transistors. Preferably, a low power, high speed CMOS driver circuit with an integrated low voltage, lateral MOSFET driver is series coupled, in a hybrid cascode arrangement to a high voltage GaN HEMT, for improved control of noise and voltage transients. Co-packaging of a GaN transistor die and a CMOS driver die using island topology contacts, through substrate vias, and a flip-chip, stacked configuration provides interconnections with low inductance and resistance, and provides effective thermal management. Co-packaging of a CMOS input interface circuit with the CMOS driver and GaN transistor allows for a compact, integrated CMOS driver with enhanced functionality including shut-down and start-up conditioning for safer operation, particularly for high voltage and high current switching. Preferred embodiments also provide isolated, self-powered, high speed driver devices, with reduced input losses.

Semiconductor devices based on gallium nitride (GaN) technology offer significant advantages over silicon technology for power electronic systems. GaN and its alloys, such as aluminum gallium nitride (AlGaN), are direct, wide band gap semiconductor materials, which have applications for microelectronic devices, including diodes and transistors for microwave and power switching circuits, as well as optoelectronics.
For power devices, GaN offers high dielectric strength, high operating temperature, high current density, high speed switching and low on-resistance. Compared to silicon, GaN has ten times the electrical breakdown strength, three times the band gap, and exceptional carrier mobility. These properties enable transistors to be produced with a on-resistance lower than attainable with silicon technology, even better than a mechanical relay contact, and allows for diodes providing a near-zero forward voltage drop. These features, together with inherently negligible charge storage, permit the design of power switching circuits with higher efficiency, smaller size and lower heat losses.
For example, as disclosed in copending PCT International patent application no. PCT/CA2012/000080 entitled "Gallium nitride power devices using island topography" (and related applications, having common ownership and inventorship with this application), GaN transistors with ultra-low on-resistance can be produced using Island Topology™. This topology provides a compact structure with a gate width double that of a conventional multi-finger design of a similar device size, with superior current handling per unit area. A breakdown voltage exceeding 1200V can be achieved.
GaN power transistors for power conversion circuits for high voltage (HV) applications, e.g. 600/650V, are typically normally-on (depletion mode) transistors. These transistors are usually driven by a series connected, discrete, power MOSFET device, i.e. in a cascode configuration, to provide normally-off operation (see FIG. 1). Conventionally, the hybrid cascode arrangement is provided with a separate, high power, high speed driver circuit, having a separate isolated power supply.
This type of hybrid cascode arrangement can provide a positive threshold voltage and further enhancement of the high Figure of Merit (FOM) of a high voltage GaN transistor. However, issues caused by transient voltages and heat dissipation can detract from performance and these issues also create challenges for the design of the driver circuit. The overall performance of hybrid cascode arrangements using existing driver circuits falls short of the potential capabilities of an individual GaN transistor.
The GaN transistor may be required, for example, to provide <20 ns switching time and more than 30 A current switching capability. Any significant series inductance at the MOSFET source or at the common node will provide unwanted L di/dt transients which can be as large as the threshold voltage of the devices, thus causing unwanted switching. It will be appreciated that in operation of an electronic power switching system that is capable of switching, for example, 30 Amps at 1000V, i.e. 30,000 Watts, safe operation may be compromised by any unwanted switching caused by transients or noise that exceeds the threshold voltage of the device.
Additionally, series resistance in the source connection results in debiasing which produces an apparent increase in the on-resistance. Thus, in conventional systems, the driver MOSFET is typically a discrete, oversized driver MOSFET that is rated to withstand ten times the static voltage stress.
To implement the series cascode connection of the two transistors and achieve high speed with low losses, the GaN transistor and a discrete vertical MOSFET are co-packaged using multiple wire bonded connections. Wire bonding is expensive, area consuming, and cumbersome. Additionally, the wire bonded interconnects represent significant inductance that contributes to high frequency switching transients and unnecessary power loss, particularly for switching speeds in the order of 100V/ns.
To reduce the inductance of the connections between the GaN transistor and the MOSFET, the two transistors are physically arranged and packaged in close proximity, to reduce interconnect length. This arrangement then presents problems for thermal management.
GaN transistors that can switch, for example, 24 A (1200 V) and 47 A (650 V) may have die sizes as small as 2×2 mm Calculations show these die, when packaged, can have a thermal resistance of greater than 2° C./W. For example, it is estimated that, for an on-resistance of 80 mΩ, the ohmic power dissipation would be 32 Watts if the device were required to sink 20 Amps The thermal resistance in total for the combination of the device, package and heat sink could exceed 5° C./W, so that the temperature increase from the GaN device dissipation alone could exceed 150° C. The additional heat dissipation of the MOSFET, assuming a 20 mΩ device is used, would be 8 Watts. With the total structure dissipating 40 Watts, the temperature within the package could exceed the safe operating limits of the MOSFET, typically 175° C., if there is insufficient heat dissipation.
Thus, conventional cascode arrangements of a GaN power transistor and a discrete driver MOSFET require complex and costly driver circuitry to manage issues with transient voltages and packaging with significant thermal dissipation capability to maintain acceptable operating temperatures.
Improvements or alternative solutions are needed to address thermal management issues, to address issues with series inductance and resistance, reduce or manage unwanted noise and voltage transients, and enable lower cost and more compact systems and devices for electronic power conversion circuits, particularly those using hybrid cascode arrangements of a normally-on GaN power transistor and a driver MOSFET.
The present invention seeks to overcome, or mitigate, one or more of the above mentioned disadvantages or limitations of these known systems and devices for electronic power conversion circuits, or at least provide an alternative.

Devices and systems for power conversion circuits


A variable track wheel comprises a rim suitable for receiving a tire, and a disc through which said wheel is mountable on a hub, said disc being removably secured by fastenings to a connecting member provided in said rim, said connecting member projecting towards a rotation axis of said wheel, said wheel further comprising a plurality of spacers interposed between an annular perimeter zone of said disc and said connecting member of said rim, said disc and said rim being mountable in a plurality of reciprocal axial positions and in a plurality of reciprocal orientations to obtain a variation in the track of said wheel, said wheel further comprising at least one centering device for mutual positioning of said disc and of said rim said centering device comprising a hole and a pin said hole or said pin being provided in said connecting member or in said disc said centering device further comprising a coupling element so conformed as to cooperate with said hole and with said pin for reciprocally coupling said pin and said hole.

The invention relates to a variable track wheel of the type comprising a rim and a disc mounted together in a removable manner.
Variable track wheels comprising a rim are known, on which the tire is mounted, having a cylindrical base on the internal circumferential surface of which there is provided a connecting member that projects radially towards the rotation axis of the wheel. A disc is removably secured to the connecting member, the wheel being fitted to a hub by means of the disc. The connecting member comprises a circumferentially continuous single annular element or a plurality of circumferentially equidistant lobes.
The disc is secured to the connecting member by fastenings, such as fixing bolts, passing through connecting holes provided in both disc and connecting member.
As the disc has a concave face and a corresponding convex fact, by varying the axial mounting position between the rim and disc, or by rotating the disc around the vertical diameter thereof, the distance varies between the median plane of the rim and the plane of the hub against which the disc is mounted, this causing a pair of wheels on the same axle to be brought nearer or moved further away. Such wheels are, for example, used as wheels of agricultural machines, such as tractors, in which, to comply with different agricultural applications, the rim and the disc must be able to be assembled according to alternative axial positions or orientations.
One drawback of variable track wheels of known type is that as they are wheels of relatively large dimensions, it is rather difficult to assemble the disc and the rim in such a manner that the respective rotation axes are effectively coaxial. In fact, gravity and the play between the fixing bolts and the connecting holes provided on both disc and connecting member, to ensure assembly thereof, cause the axis of the disc, once mounted, not to be aligned on the axis of the rim. This axial misalignment between rim and disc has a negative effect on the stroke and performance features of the vehicle on which the wheel is mounted. In particular, the misalignment causes vibrations that are transmitted to the vehicle, with the risk of causing the driver problems of comfort or even problems of safety due to instability of the vehicle.
This is particularly relevant to vehicles that are arranged for travelling at relatively high speeds, for example even at 50 kilometers an hour.
Variable track wheels are known in which the misalignment of the axes of the disc and of the rim has been considered.
EP0808250 discloses a variable track wheel in which the disc is provided with additional holes that during mounting are aligned on at least two indicators or holes provided on the rim and reciprocally coupled by centering plugs that can be removed once the fixing bolts have been tightened.
EP0911183 discloses a variable track wheel wherein the disc is provided with a pair of diametrically opposite centering pins, arranged for coupling with a plurality of pairs of corresponding diametrically opposite holes obtained on the connecting member.
The centering systems of known type are not designed for repeating centering during mounting of the disc and of the rim after first mounting.
In fact, during removal of the centering pins or during subsequent inserting of the pins into the corresponding holes, the walls of the holes into which the centering pins have to be inserted for centering can become damaged, this causing possible play that reduces the precision of the subsequent mounting.
Still another drawback of known systems is that in the event of replacement of only the rim or only the disc with a new rim or a new disc, the new rim or the new disc has to be provided with holes or pins having dimensions that are compatible with those found on the piece with which they have to be coupled. This means that a large number of spare parts have to be kept in store so that one disc model can be mounted on a plurality of models of rim and vice versa the same centering system can be maintained.
Alternatively, to mount, for example, a new disc on an old rim, it is necessary to work on the old rim or on the new disc, for example, to match the dimensions of the holes with those of the pins, this increasing significantly the time and cost of replacement. Lastly, the centering systems of known type are not effective on all the types of variable track wheel, in particular on wheels comprising spacers between the disc and connecting member.
One object of the invention is to improve the centering systems of known type to limit the misalignment of the axes of the disc and of the rim of a wheel. A further object is to obtain a variable track wheel in which the disc and the rim can be replaced individually with spare parts, without it being necessary to perform mechanical machining to adapt the centering system of the spare part with that of the disc and/or of the rim that has not been replaced.
Still another object is to provide a centering system that can be applied to a variable track wheel comprising spacers between the disc and connecting member. Another object is to obtain a variable track wheel in which the mounting position between disc and rim ensures a set balance of the wheel.
A still further object is to produce a variable track wheel, in which the mounting position between disc and rim corresponding to a set balance of the wheel can be refound with a certain precision at each reassembly of the disc of the rim following the first mounting during manufacture.
According to the invention, a variable track wheel is provided comprising a rim that is suitable for receiving a tire, and a disc through which said wheel is mountable on a hub, said disc being removeably secured by fastenings to a connecting member provided in said rim, said connecting member projecting towards a rotation axis of said wheel, said wheel further comprising a plurality of spacers interposed between an annular perimeter zone of said disc and said connecting member of said rim, said disc and said rim being mountable in a plurality of reciprocal axial positions and in a plurality of reciprocal orientations to obtain a variation in the track of said wheel, said wheel further comprising at least one centering device for mutual positioning of said disc and of said rim, said centering device comprising a hole and a pin, said hole or said pin being provided in said connecting member or in said disc, characterized in that said centering device further comprises a coupling element shaped in such a manner as to cooperate with said hole and with said pin for mutually coupling said pin and said hole.
Owing to the coupling element, the diameter of the hole/pin provided on the connecting member can also be substantially different from the diameter of the pin/hole provided on the disc, inasmuch as it is the coupling element that adapts the dimensions of the hole to those of the pin.
In one embodiment, the wheel comprises two centering devices, each of which is provided with a corresponding coupling element.
In a further embodiment, the two centering devices are diametrically opposite and are dimensionally different from one another, i.e. the pin, the hole and the coupling element of the first centering device have dimensions—in particular the diameter—other than those of the respective pin, hole and coupling element of the second centering device.
This enables the mounting position of the rim and of the disc to be found unequivocally, whatever the mutual axial position or orientation of the rim and disc, and enables a set balance of the wheel to be obtained.
As the wheel comprises spacers that are interposed between said connecting member and said disc and retained between said connecting member and said disc by the fastenings, in particular by bolts, the coupling element, in addition to coupling the pin with the hole, compensates the distance imposed by the spacers between the disc and the connecting member.

Variable track wheel and associated systems and methods


In a single-carrier frequency division multiple access (SC-FDMA) system that utilizes interleaved FDMA (IFDMA) or localized FDMA, multiple transmitters may transmit their pilots using time division multiplexing (TDM), code division multiplexing (CDM), interleaved frequency division multiplexing (IFDM), or localized frequency division multiplexing (LFDM). The pilots from these transmitters are then orthogonal to one another. A receiver performs the complementary demultiplexing for the pilots sent by the transmitters. The receiver may derive a channel estimate for each transmitter using an MMSE technique or a least-squares technique. The receiver may receive overlapping data transmissions sent on the same time-frequency block by the multiple transmitters and may perform receiver spatial processing with spatial filter matrices to separate these data transmissions. The receiver may derive the spatial filter matrices based on the channel estimates for the transmitters and using zero-forcing, MMSE, or maximal ratio combining technique.

I. Field
The present disclosure relates generally to communication, and more specifically to pilot and data transmission in a wireless communication system.
II. Background
A multiple-access system can concurrently communicate with multiple terminals on the forward and reverse links. The forward link (or downlink) refers to the communication link from the base stations to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the base stations. Multiple terminals may simultaneously transmit data on the reverse link and/or receive data on the forward link. This is often achieved by multiplexing the multiple data transmissions on each link to be orthogonal to one another in time, frequency and/or code domain. Complete orthogonality among the multiple data transmissions is typically not achieved in most instances due to various factors such as channel conditions, receiver imperfections, and so on. Nevertheless, the orthogonal multiplexing ensures that the data transmission for each terminal minimally interferes with the data transmissions for the other terminals.
The number of terminals that can communicate with the multiple-access system at any given moment is typically limited by the number of traffic channels available for data transmission, which in turn is limited by the available system resources. For example, the number of traffic channels may be determined by the number of available orthogonal code sequences in a code division multiple access (CDMA) system, the number of available frequency subbands in a frequency division multiple access (FDMA) system, the number of available time slots in a time division multiple access (TDMA) system, and so on. In many instances, it is desirable to allow more terminals to simultaneously communicate with the system in order to improve system capacity.
There is therefore a need in the art for techniques to support simultaneous transmissions for more terminals in a multiple-access system.

Pilot and data transmission in a quasi-orthogonal single-carrier frequency division multiple access system


A method includes providing a computer readable code configured to perform a process of feature management. The computer code includes one or more configurable features having a feature property. The feature property includes a state. The method also includes: running the computer readable code on the local computer; connecting by the local computer with a feature computer server; identifying an instance of an installed computer program including the computer readable code, and retrieving a feature record associated with the installed computer program or the member from the feature server; and configuring a state of one or more of a set of the feature properties of the installed computer program based on a retrieved feature record. A system to perform the method is also described.

Computer programs are often made available about the same time in more than one version. The different versions of a computer program generally vary by the number of features made available to a user of the computer program. The most common way to install a given version of a computer program is to install the entire framework of that version of the computer program. Accordingly, when upgrading an already installed computer program, a successive installation usually replaces the existing computer program framework during the subsequent installation. This user process of upgrading an already installed computer program by replacing the currently installed program framework is inefficient.
There is a need for a more efficient system and method to provide a modified or upgraded computer program which offers a different set of features, without needing to replace the underlying framework of an already installed computer program.

System and method for software feature management


Peptides derived from human interleukin-4 are provided comprising from 6 to 40 amino acids. Conjugates of the peptides and carriers are also provided for the production of polyclonal and/or monoclonal antisera to human interleukin-4.

The present invention relates generally to peptides useful in the production of polyclonal and/or monoclonal antibodies, and more particularly, to peptides derived from the human lymphokine, interleukin-4 (IL-4).
For some time, it has been known that the mammalian immune response is based on a series of complex cellular interactions, called the "immune network." Recent research has provided new insights into the inner workings of this network. While it remains clear that much of the response does, in fact, revolve around the network-like interactions of lymphocytes, macrophages, granulocytes and other cells, immunologists now generally hold the opinion that soluble proteins (e.g., the so-called "lymphokines" or "monokines") play a critical role in controlling these cellular interactions. Thus, there is considerable interest in the isolation, characterization, and mechanisms of action of cell modulatory factors, an understanding of which should yield significant breakthroughs in the diagnosis and therapy of numerous disease states.
Lymphokines apparently mediate cellular activities in a variety of ways. They have been shown to support the proliferation, growth and differentiation of the pluripotential hematopoietic stem cells into the vast number of progenitors composing the diverse cellular lineages responsible for the immune response. These lineages often respond in a different manner when lymphokines are used in conjunction with other agents.
Cell lineages that are especially important to the immune response include two classes of lymphocytes: B-cells, which can produce and secrete immunoglobulins (proteins with the capability of recognizing and binding to foreign matter to effect its removal), and T-cells of various subsets that secrete lymphokines and induce or suppress the B-cells and some of the other cells (including other T-cells) making up the immune network.
Another important cell lineage is the mast cell (which has not been positively identified in all mammalian species)--a granule-containing connective tissue cell located proximal to capillaries throughout the body, with especially high concentrations in the lungs, skin, and gastrointestinal and genitourinary tracts. Mast cells play a central role in allergy-related disorders, particularly anaphylaxis as follows: when selected antigens crosslink one class of immunoglobulins bound to receptors on the mast cell surface, the mast cell degranulates and releases the mediators (e.g., histamine, serotonin, heparin, prostaglandins, etc.) which cause allergic reactions, e.g., anaphylaxis.
Research to better understand (and thus potentially treat therapeutically) various immune disorders has been hampered by the general inability to maintain cells of the immune system in vitro. Immunologists have discovered that culturing these cells can be accomplished through the use of T-cell and other cell supernatants, which contain various growth factors, such as some of the lymphokines.
The detection, isolation and purification of these factors is extremely difficult, being frequently complicated by the complexity of the supernatants they are typically located in, the divergencies and cross-overs of activities of the various components in the mixture, the sensitivity (or lack thereof) of the assays utilized to ascertain the factors' properties, the frequent similarity in the range of molecular weights and other characteristics of the factors, and the very low concentration of the factors in their natural setting.
As more lymphokines become available, primarily through molecular cloning, interest has heightened in finding clinical applications for them. Because of physiological similarities to hormones (e.g., soluble factors, growth mediators, action via cell receptors), potential uses of lymphokines have been analogized to the current uses of hormones, e.g. Dexter, Nature, Vol. 321, pg. 198 (1986). One hope is that the levels of lymphokines in a patient can be manipulated directly or indirectly to bring about a beneficial immune response, e.g. suppression in the case of inflammation, allergy, or tissue rejection, or stimulation or potentiation in the case of infection or malignant growth. Other potential clinical uses of lymphokines include maintaining and expanding in vitro populations of certain immune system cells of one person for eventual reintroduction into the same or another person for a beneficial effect. For example, investigations are currently underway to determine whether populations of lymphokine-activated killer T cells of a patient can be expanded outside his or her body then reinjected to bring about an enhanced antitumor response. Another potential clinical use of lymphokines, particularly colony stimulating factors, such as granulocyte-macrophage colony stimulating factor (GM-CSF), and factors which enhance their activities, is stimulating blood cell generation, for example, in pre- or post-chemotherapy or radiation therapy against tumors, in treatment of myeloid hypoplasias, or in treatment of neutrophil deficiency syndromes, Dexter, Nature, Vol. 321, pg. 198 (1986). Another area where such factors would be useful is in bone marrow transplant therapy, which is being used increasingly to treat aplastic anemia and certain leukemias.
There are two properties of lymphokines that have important consequences for such clinical applications: Individual lymphokines are frequently pleiotropic. And the biological effects of one lymphokine can usually be modulated by at least one other lymphokine, either by inhibition or by potentiation. For example, tumor necrosis factor, which synergizes with gamma-interferon, stimulates interleukin-1 (IL-1) production and can activate the phagocytic activity of neutrophils. IL-1, a protein produced by activated macrophages, mediates a wide range of biological activities, including stimulation of thymocyte proliferation via induction of interleukin-2 (IL-2) release, stimulation of B-lymphocyte maturation and proliferation, fibroblast growth factor activity and induction of acute-phase protein synthesis by hepatocytes. IL-1 has also been reported to stimulate prostaglandin and collagenase release from synovial cells, and to be identical to endogenous pyrogen, Krampschmidt, J. Leuk. Biol., Vol. 36, pgs. 341-355 (1984).
Interleukin-2, formerly referred to as T-cell growth factor is a lymphokine which is produced by lectin-or antigen-activated T cells. The reported biological activities of IL-2 include stimulation of the long-term in vitro growth of activated T-cell clones, enhancement of thymocyte mitogenesis, and induction of cytotoxic T-cell reactivity and plaque-forming cell responses in cultures of nude mouse spleen cells. In addition, like interferons (IFNs), IL-2 has been shown to augment natural killer cell activity, suggesting a potential use in the treatment of neoplastic diseases, Henney et al., Nature, Vol, 291, pgs. 335-338 (1981). Some success has been reported in such therapy, e.g. Lotze and Rosenberg, "Treatment of Tumor Patients with Purified Human Interleukin-2," pgs. 711-719, in Sorg et al., Eds. Cellular and Molecular Biology of Lymphokines (Academic Press, Inc., New York, 1985); and Rosenberg and Lotze, "Cancer Immunotherapy Using Interleukin-2 and Interleukin-2 Activated Lymphocytes," Ann. Rev. Immunol., Vol. 4, pgs. 681-709 (1986). However, IL-2 toxicity has limited the dosages which can be delivered to cancer patients for taking advantage of these properties, Lotze and Rosenberg, pgs. 711-719; and Welte et al., pgs. 755-759, in Sorg et al. Eds. (cited above).
Recently a new human lymphokine, designated interleukin-4 (IL-4), has been cloned and characterized, Lee et al., U.S. patent application Ser. No. 799,668 filed Nov. 19, 1985; Lee et al., U.S. patent application Ser. No. 881,553 filed 3 Jul. 1986; Yokota et al., Proc. Natl. Acad. Sci., Vol. 83, pgs. 5894-5898 (1986) and IL-4 is a highly pleiotropic lymphokine which exhibits activities including T cell growth factor (TCGF) activity, B cell growth factor (BCGF) activity, interleukin-2 TCGF potentiating activity, potentiation of granulocyte and macrophage colony stimulating factor (GM-CSF) stimulated granulocyte colony formation, and IgE and IgG.sub.1 induction activity. These activities suggest several possible therapeutic uses, e.g. as a potentiating agent for IL-2 anticancer therapy, as a potentiating agent for GM-CSF stimulated bone marrow regeneration, or as an agent to treat bare lymphocyte syndrome, Touraine, Lancet, pgs. 319-321 (Feb. 7, 1981); Touraine and Bethel, Human Immunology, Vol. 2, pgs. 147-153 (1981); and Sullivan et al., J. Clin. Invest., Vol. 76, pgs. 75-79 (1985).
An important aspect of any therapy involving drugs is the ability to predict and/or monitor concentration levels in the blood. Monoclonal antibodies are widely used for this purpose, e.g. Springer, ed., Hybridoma Technology in the Biosciences and Medicine (Plenum Press, N.Y., 1985); and U.S. Pat. Nos. 4,562,003; 4,486,530; and 4,255,329.
In the production of genetically engineered proteins such as IL-4, separation of the expressed protein from the transformed host cells and/or their culture supernatants is a major problem. Frequently separation procedures involve one or more passes of crude material through immunoadsorbent columns. Monoclonal antibodies specific for the protein to be purified are crucial elements of such columns. Also, such monoclonal antibodies can be used to measure the degree of purification by immunoprecipitation of elechophoretically separated proteins, or by "Western" blot analysis, e.g. Burnette, Anal. Biochem., Vol. 112, pgs. 195-203 (1981).
From the foregoing it is evident that the availability of monoclonal and/or polyclonal antibodies specific for IL-4 could facilitate medical and veterinary applications of the compound by improving current methods of purification, and by providing means for monitoring concentrations of IL-4 in body fluids, such as blood, urine, or the like.

Human interleukin-4 peptides and conjugates thereof


A mill is used to break up ores or gravel in which gold particles are to be found. The mill comprises an outer casing in which an internal housing is located. Within the internal housing is a rotor which rotates at about 1000-15000 rpm. The rotor has cam surfaces on its circumference which impacts the ore and forces it onto a plurality of planar surfaces on the inside of the housing. The ore is broken up by the impacting and is then forced through an outlet passage into an outlet chamber where the heavier gold particles are removed from the lighter non-gold particles.

In the mining and milling of gold bearing ore, there are known machines which are used for impaction of the ore particles in a dry state.
These machines are basically drums into which the gold bearing ore is deposited. The drums have internally a plurality of rotor discs and hammers which are rotated at approximately 1000-1500 rpm, forcing the ore onto a series of plate members formed on the inside of the drum wall. The rotational speed of the rotor ensures that the ore particles are impacted at great speed. The different particles in the ore once broken down are able to be concentrated wherein the gold particles are concentrated at the bottom of the machine whilst the lighter materials are discharged.


The method of this invention includes the steps of positioning a reseau with grid marks on the object and sequentially illuminating the grid marks separate from the object and illuminating the object separate from the grid marks or in a manner that the grid marks are not visible with the object. The image of the grid mark positions, when illuminated, are digitized and stored in computer memory and correlated with the image of the object when it is illuminated and digitized. The scale of the image can also be correlated to the scale of the grid marks.

1. Field of the Invention
This invention relates to digital photogrammetric processes and more specifically to a method of photogrammetric image mensuration in which grid marks can be provided, yet can be made invisible to an image of the object to be mensurated and analyzed.
2. Background of the Invention
The photographic art for aerial surveillance, geological and archaeological study, mechanical, industrial, and architectural design and analysis, and other uses has become very well-developed over the past several decades so that sharp, clear photographic images of the earth's surface and of objects on the earth's surface are obtainable from aerial photography, satellite photography, and the like. In fact, there already are in existence virtually countless aerial photographs in files of national, state, and local government agencies, corporations, and individuals for purposes ranging widely from such things as military reconnaissance, surveillance and measurement of agricultural land and crop conditions, monitoring municipal development and growth patterns, map making, geologic assaying, land management, and the like. Additional photographing and rephotographing for subsequent comparison with previous conditions are being done on an increasing basis.
For many purposes, however, analysis of such photographic images cannot be done by visual observation with sufficient accuracy or efficiency. For example, in spite of having exceptionally clear aerial photographic images available, it may be quite impossible, even with accurate graphic instruments and a magnifying glass, to measure the wing-span of an airplane parked on an airport apron, the square feet of pavement on all of the streets in a city, or the areas of potholes in a wetlands inventory of a prairie.
Therefore, to improve their accuracy and efficiency, persons skilled in the art of photogrammetry have found that computers can be a very useful tool for enhancing the photographic images or parts of the images and to augment the analysis. To do so, the photographic image is converted into a digital format that can be stored, processed, and displayed on a computer controlled graphic display output, such as a cathode ray tube (CRT), hard copy printer, plotter, or the like.
A common method of converting a hard copy image to a digital array is to use a point sensor, such as a charge-coupled device (CCD), charge injection device (CID), or photodiode to scan the surface of the hard copy and measure the light either transmitted through, or reflected from, various points on the hard copy. The hard copy in this kind of process is usually mounted on a rotating drum or on a flat table that is movable in orthogonal X-Y directions. A large pixel array, such as a 20,000 by 20,000 pixel area, can be acquired, which may, for example, be the pixel array needed to represent the information on a 9".times.9" (23 cm.times.23 cm) film image, assuming individual pixels of about 12.5 um diameter.
Some systems use a linear detector or sensor array, instead of a single point sensor for the digital data acquisition. In such linear systems a large number (e.g., 1750) of individual light sensitive elements are grouped together in a linear row, and this linear array or row of sensors is used to sweep scan a path over the surface of the hard copy.
Precise mechanical motion control is required for both the individual scan lines of a single point sensor and the groups of scan lines or sweep path of linear arrayed sensors in order to obtain a meaningful and useable pixel array of the photogrammetric image. Such mechanical accuracy, while necessary for accurate pixel designation and resolution, cannot be obtained economically in the degree that would be required for resolution commensurate to pixel sizes of less than, for example, 50 microns. Also, typical operations problems with such systems usually result from inability to achieve and maintain the mechanical accuracy needed over long periods of time. Consequently, the large data arrays required and the high cost to obtain the necessary mechanical accuracy have kept the use of digital image processing of photographic images in laboratories only and away from general commercial application and use.
In recent years, several manufacturers have made available semiconductor chips on which a plurality of CCD's or CID's are arranged in a two-dimensional, rectangular array and mounted in a solid state camera, such as a "TM-540", manufactured by Pulnix, of Sunnyvale, Calif. These solid state cameras with rectangular sensor arrays can detect and measure light from a fixed frame or rectangular portion of the image that a person desires to digitize for computer use. When such cameras are used in conjunction with an analog to digital converter (sometimes called a "frame grabber" device), the signal point or linear array scanning is no longer required to acquire a pixel array of digital values for a photogrammetric computer image of a hard copy photograph, transparency, drawing, or the like. The physical spacings and sizes of the pixels are fixed by the geometric CCD or CID array and by the magnification of the hard copy image to the CCD or CID array.
These "frame grabbing" solid state cameras typically have rectangular arrays, such as, for example, about 510.times.492 CCD's or CID's. When properly focused on an image, each CCD or CID in the array detects light intensity from an individual spot or pixel area on the film image. Thus, a solid state camera that has an array of 510.times.492 CCD's on a rectangular chip will convert the portion of a film image within a focused frame to a square pixel array of 510.times.492, i.e., about 250,920 light intensity measurements or signals. Such an array of intensity measurements can, of course, be recorded and displayed by a computer on a CRT in the same pixel array to provide a computer image reproduction of the portion of the film image within the focused or "grabbed frame". There has been a recent announcement by at least one manufacturer that a solid state CCD camera with a 1,000 .times.1,000 pixel array will soon be available, which will provide larger "grabbed" frames, more accuracy, or a combination of both.
While the "frame grabbing" solid state cameras with rectangular CCD or CID arrays eliminate scanning, as described above, they are applicable only where a limited size pixel array is needed. For example, such a "frame grabber" may be useful in focusing onto, and acquiring a digital image of, a particular small object, such as an airplane, that can be seen in an aerial photograph of a ten square kilometer area. However, they have not been useful before this invention for "grabbing" and digitizing larger film image areas. In order to "grab" and digitize a larger film image area, the solid state camera had to be focused over a larger film area, thus sacrificing detail accuracy, since each pixel size within the array also is focused over a larger area.
There are at least two products now available that can create a large pixel array by combining a "frame grabbing" two-dimensional image array with a scanning motion. In such systems, individual frames or sub-areas of larger macroareas of film or paper photographs can be "grabbed" or digitized and stored. Then, adjacent frames can be "grabbed" and positioned correctly in the computer memory by either (1) moving the "frame grabbing" solid state camera very precisely to a predefined adjacent position mechanically and then "grabbing" the pixel array for that adjacent position, or (2) by moving the camera less precisely to "grab" the image at the adjacent location and 5 relying on a precisely located grid mark or pattern of grid marks to geometrically relate one "grabbed" sub-area to the next "grabbed" sub-area. The "Autoset-1" manufactured by Geodetic Services Incorporated, of Melbourne, Fla. is an example of the former of these techniques, and the "Rolleimetric RS", manufactured by Rollei Fototechnic GmbH, of Braunschweig, West Germany, is an example of the latter technique.
In general, reasonably priced opto-mechanical scanners have not been able to achieve the accuracy considered to be necessary for many of the newly-evolving applications. Scanners that could achieve high geometric resolution are slow and often force a user to resort to an off-line scanning process separate from the process of actually using and analyzing the data.
Frame grabbing solid state camera systems, as described above, provide a higher degree of accuracy within a small frame pixel array sub-area. However, combining frame grabbing with scanning to get digital data over a larger macro-area again usually sacrifices accuracy for economy or economy for accuracy due to the need for highly accurate mechanical position control. The Rollei system mentioned above, and further described in the West German patent no. DE 3428325, is considered to be a significant advancement in this regard by teaching the use of reseau grids in combination with a "frame grabbing" solid state camera, but it still requires manual identification of reseau grids or crosses. Also, the reseau crosses or grids are visible in the image and obliterate some of the contents of the photographic image where the grid marks are located. Also, the process of using a reseau in that manner is slow.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a fast, accurate, yet relatively inexpensive image digitizing and mensuration system for analyzing hard copy photographic, transparency, paper drawing, radar, and other images.
A more specific object of the present invention is to provide an improved mensuration frame grabbing system for digitizing and analyzing hard copy photographic, transparency, paper drawing, radar, and other images.
A still more specific object of the present invention is to provide an improved reseau grid for a mensuration frame grabbing system in which the reseau grid does not obscure or cover any part of the image and does not become a part of the image.
Another specific object of the present invention is to provide a frame grabbing digitizing mensuration system that uses a reseau grid location reference system in which individual reseau detection and location is automatic.
Still another specific object of this invention is to provide an image digitizing system in which one or more specific sub-areas of a large macro-area image can be converted to digital format without having to convert the entire macro-area image to digital format if not desired, thus avoiding the use of unnecessary computer storage and off-line creation of a large pixel array and allowing mass storage of currently uninteresting image to be kept on film only, yet which also has the capability of digitizing an entire large format macro-area image, if desired, in an efficient, accurate manner.
A further specific object of the present invention is to provide a system that can quickly and accurately digitize a select feature shown in stereo photographs, correlate the digital images, and display them in a stereo image, such as a three-dimensional display or other stereo overlapping images, on a CRT, graphic display device, or the like.
A still further object of the present invention is to provide a relatively inexpensive, compact apparatus for digitizing and analyzing hard copy images in which all parts of a large hard copy image are kept visible and stationary at all times.
Additional objects, advantages, and novel features of this invention are set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following specification or may be learned by the practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and in combinations particularly pointed out in the appended claims.
To achieve the foregoing and other objects and in accordance with the purposes of the present invention, as embodied and broadly described herein, the method and apparatus of this invention includes the steps of positioning below a solid state camera a reseau with grid marks thereon adjacent an object with an image and activating one of several grid mark visibility means. Digitizing the grid marks and storing the digitized data including spatial location in a computer memory. Removing the grid marks from the capability of the solid state camera to view them and digitizing the image on the object and storing the digitized data of the object in a computer memory. Correlating the digitized data of the grid marks with that of the image of the object for the purpose of computer controlled visual display and/or mensuration of the image by the computer, with respect to a scale calibrated by the computer from the digitized reseau grid marks.
There are several methods and associated apparatus for making the grid marks visible at one time and then invisible at another according to this invention. One such method is to fit the solid state camera with a gain control and to make the reseau grid mark visible by illumination with high intensity light, such as Xenon light. The intensity of Xenon light makes it possible to have the grid marks and object illuminated simulataneously and still allow the camera to distinguish and digitize the grid marks. The invisibility of the marks occurs when the Xenon light is removed. Another method is to have the reseau grid formed from a light polarizing material and making the reseau grid marks visible by passing light polarized perpendicular to the polarizing material. The grid marks become invisible when unpolarized light or light polarized parallel to the polarizing material is allowed to pass through the reseau. A third method is having the reseau grid formed on an electrochromic active film on the reseau plate, whereby the reseau grid marks are made visible by placing an electric potential across the reseau. Conversely, the marks are made invisible by removing the electric potential from across the reseau. A fourth method includes filtering the solid state camera with a filter that includes a clear, colored, or infrared filter and making the reseau grid a specific color or infrared by illumination with light of that wavelength or deposition of a material that either reflects light of that wavelength or allows light of that wavelength to pass through. The reseau grid marks are made visible by illumination of the reseau, and placing a filter not corresponding to the wavelength transmitted by the grid marks before the camera. Conversely, the grid marks are made invisible by placing the colored or infrared filter before the camera, corresponding to the wavelength transmitted by the grid marks. A fifth method includes separating the reseau grid from the object with sufficient distance that the solid state camera's focal length and depth of field allows the camera to focus on only the reseau grid marks or the object but not both. The grid marks can be made visible by adjustment of the camera's focus such that the grid marks are in focus and the image in the object is essentially washed out. Conversely, the grid marks can be made invisible by adjusting the focus such that the grid marks are washed out and the image on the object is in focus.

Method and apparatus of image mensuration with selectively visible and invisible reseau grid marks


A tray assembly for use with an existing cutting board to provide additional storage and space when cooking. The assembly includes at least two adjustable legs that are securable to the cutting board for either raising the cutting board above a surface or suspending the cutting board between two walls, such as a sink. One end of each leg includes a fastener, such as a C-clamp for attaching to the cutting board. The assembly further includes four trays movably secured to a plate. The plate is configured to rest beneath the cutting board when in a raised position. Each tray is positioned along a distinct sidewall of the plate and configured to extend beyond the edges of the cutting board when extended. For additional storage, a divider frame secures to each tray when in the extended position, forming an additional center tray.

The present invention relates to assemblies for cutting boards. The present invention more specifically provides a pair of adjustable legs that secure to a cutting board for raising the cutting board above a surface and a plate having a plurality of trays configured to rest beneath the cutting board when in the raised position.
Cutting boards used to chop vegetables, fruit, meat, and other food items, protect countertop surfaces and provide a clean area for resting food upon. However, the surface area where the cutting board rests becomes a useless storage space or a diminished work zone when in use. The cutting board is a versatile work space at the start of chopping, but its use is greatly diminished as more of the food products are cut up with both desired and unwanted portions, such as inedible portions, skins, peels, and the like. This mass of chopped food prevents further chopping of food stuffs, requiring the cutting board to be cleared in some fashion or an additional cutting board to be placed on another portion of available workspace.
As a solution, some people choose to use receptables, such as bowls or pans, that sit alongside a cutting board to receive discarded or chopped food. The addition of these receptacles to the work counter further reduces the available countertop space in the kitchen, making cooking and prep work even more difficult and cramped.
There remains a need for a cutting board that protects the countertop from damage and food stuffs, but also provides storage for chopped material without further reducing the available kitchen workspace.
The present invention is configured to secure to an existing cutting board and create additional storage space under the cutting board, making chopping much more efficient and expeditious. The assembly includes a plate having four trays removably or movably secured thereto. The plate is configured to rest beneath the cutting board when in a raised position. Each tray is positioned along a distinct sidewall of the plate and configured to extend beyond the edges of the cutting board when extended therefrom. In some embodiments, the first tray is void of a rear wall in order to receive the opposing second tray when in the retracted position. The third and fourth trays oppose one another and are smaller in size than the first and second catch pan in order to fully retract onto the plate. In alternate embodiments, the third and fourth trays are detached from the plate and nested within the first and second trays for storage. Each tray can be used as a waste bin, storage for a type of vegetable or other food waiting to be chopped, storage for chopped food, and the like.
In light of the devices disclosed in the known art, it is submitted that the present invention substantially diverges in design elements and methods from the known art and consequently it is clear that there is a need in the art for an improvement for tray assembly for a cutting board. In this regard the instant invention substantially fulfills these needs.


A cleaning device of the present invention includes a brush roller having a brush held in contact with the surface of a body to be cleaned. The brush contacts the surface of the body to be cleaned due to the weight of the brush roller and rotates by following the movement of the above surface. A flicker is held in contact with the brush in order to remove toner deposited on the brush. A casing forms a chamber therein for storing the toner removed by the flicker. The brush roller maintains an expected cleaning ability even when impurities deposited on the brush absorb moisture in a high-humidity environment and cannot be easily removed or when a great amount of toner deposits on the brush at a time.

1. Field of the Invention
The present invention relates to a copier, printer, facsimile apparatus or similar image forming apparatus and more particularly to a cleaning device for an image forming apparatus.
2. Description of the Background Art
A cleaning device for cleaning a desired member has customarily been used in machines and apparatus in various fields. An image forming apparatus, for example, includes a cleaning device for cleaning the surface of an image carrier, a cleaning device for cleaning the surface of a charge roller that charges the image carrier, and a cleaning device for cleaning the surface of an image transfer belt.
Japanese Patent Laid-Open Publication No. 7-140763, for example, discloses a cleaning device using a brush roller that contacts the surface of a member to be cleaned. The brush roller is rotated by a drive source. A brush on the brush roller and the surface of the member to be cleaned each are moved at a particular linear velocity, so that the brush scrapes off impurities deposited on the member.
However, the conventional brush roller type of cleaning device needs the drive source for driving the brush roller. Moreover, this type of cleaning device needs means for limiting the amount of bite of the brush into the desired member in order to control the permanent deformation of the brush. This increases the cost of the cleaning device and makes the cleaning device sophisticated. It is to be noted that the amount of bite of the brush refers to the maximum amount of deformation of the brush roller to occur in the radial direction when the brush is pressed against the surface of the desired member. It has been customary to control the yield of the brush by confining the amount of bite in an adequate range.
On the other hand, assume that impurities deposited on the brush of the brush roller absorb moisture in a high-humidity environment and cannot be easily removed or that a great amount of toner deposits on the brush at a time. Then, the cleaning ability of the brush roller falls with the result that a body to be cleaned is contaminated and brings about defective images. Further, to meet the increasing demand for the reduction of running cost, it is necessary to extend the lives of parts and those of units.
Technologies relating to the present invention are also disclosed in, e.g., Japanese Patent Laid-Open Publication Nos. 8-22173, 10-20696, 10-282854 and 11-219048.
It is an object of the present invention to provide a cleaning device whose brush roller maintains an expected cleaning ability even when impurities deposited on its brush absorb moisture in a high-humidity environment and cannot be easily removed or when a great amount of toner deposits on the brush at a time, thereby obviating defective images ascribable to the contamination of a body to be cleaned.
It is another object of the present invention to provide a cleaning device having a brush roller constructed into a unit for thereby extending the life of the brush roller while promoting easy, rapid replacement.
It is a further object of the present invention to provide a cleaning device having an enhanced ability to scrape off impurities deposited on a brush and achieving an extended service life.
A cleaning device of the present invention includes a brush roller having a brush held in contact with the surface of a body to be cleaned. The brush contacts the surface of the body to be cleaned due to the weight of the brush roller and rotates by following the movement of the above surface. A flicker is held in contact with the brush in order to remove toner deposited on the brush. A casing forms a chamber therein for storing the toner removed by the flicker.

Image forming apparatus and cleaning device therefor


A method for treating a human patient is provided, including administering a radiolabeled form of a therapeutic agent to the patient at a first substantially non-therapeutically-effective dose, wherein pharmacological activity of the therapeutic agent is not due to radioactivity of the therapeutic agent. The method also includes determining information related to a biodistribution of the radiolabeled form of the therapeutic agent in the patient by performing a radioimaging procedure on the patient. Responsively to the information, a decision is made whether or not to treat the patient by administering the therapeutic agent to the patient. If the decision is made to treat the patient, the patient is treated by administering the therapeutic agent to the patient at a second therapeutically-effective dose. If the decision is made not to treat the patient, treatment of the patient with the therapeutic agent is withheld. Other embodiments are also described.

PCT Publication WO 06/051531 to Rousso et al., which is assigned to the assignee of the present application and is incorporated herein by reference, describes radioimaging methods, devices and radiopharmaceuticals.
U.S. Pat. No. 6,242,743 to DeVito et al., which is incorporated herein by reference, describes a tomographic imaging system which images ionizing radiation such as gamma rays or x rays. The system is described as being capable of producing tomographic images without requiring an orbiting motion of the detector(s) or collimator(s) around the object of interest, and of observing the object of interest from sufficiently many directions to allow multiple time-sequenced tomographic images to be produced. The system consists of a plurality of detector modules which are distributed about or around the object of interest and which fully or partially encircle it. The detector modules are positioned close to the object of interest thereby improving spatial resolution and image quality. The plurality of detectors view a portion of the patient or object of interest simultaneously from a plurality of positions. These attributes are achieved by configuring small modular radiation detector with high-resolution collimators in a combination of application-specific acquisition geometries and non-orbital detector module motion sequences composed of tilting, swiveling and translating motions, and combinations of such motions. Various kinds of module geometry and module or collimator motion sequences are possible. The geometric configurations may be fixed or variable during the acquisition or between acquisition intervals.
The Bexxar® (GlaxoSmithKline) therapeutic regimen (Tositumomab and Iodine I-131 Tositumomab) is indicated for the treatment of patients with CD20 antigen-expressing relapsed or refractory, low-grade, follicular, or transformed non-Hodgkin's lymphoma, including patients with Rituximab-refractory non-Hodgkin's lymphoma. The Bexxar therapeutic regimen is delivered in two sets of intravenous infusions given 7-14 days apart. A trace amount of radioactive Iodine-131 tositumomab, is initially given to enable evaluation of the clearance of radiation from the patient's body with gamma camera scans. A therapeutic dose, which is given 7-14 days after the dosimetric infusion, is tailored for each patient based on the patient's individualized radiation clearance rates. The therapeutic dose contains tositumomab labeled with the amount of I-131 tositumomab specifically calculated for the patient based on the scans performed following the dosimetric dose.
Following the infusion of the dosimetric dose, counts are taken with a gamma camera to track the elimination of radiation from the body. The patient then returns to the hospital for two more scans, approximately two days apart. These procedures are important because highly individual factors such as tumor size, bone marrow involvement, and spleen size affect how long the radiation remains in the body. Dosimetry, therefore, allows the amount of I-131 radiation administered in the therapeutic dose to be adjusted for each patient so that the optimal target dose of radiation is achieved for maximum effectiveness while minimizing toxicities.
U.S. Pat. No. 6,287,537 to Kaminski et al., which is incorporated herein by reference, describes methods for the treatment of lymphoma by administration of a B cell-specific antibody. The invention includes providing to a patient both unlabeled antibodies and antibodies labeled with a radioisotope. A principal advantage of the method is that tumor responses can be obtained in a radiometric dose range that does not require hematopoietic stem cell replacement as an adjunct therapy. One method described for using B1 antibody includes administering a trace-labeled amount of B1 antibody, followed by imaging of the distribution of the B1 antibody in the patient. After imaging, a therapeutic regime of radiolabeled B1 is administered, designed to deliver a radiometric dose of 25 to 500 cGy, preferably 25 to 150 cGy, to the whole body of the patient.
Van Den Bossche B et al., in "Receptor imaging in oncology by means of nuclear medicine: current status," Journal of Clinical Oncology 22(17):3593-3607 (2004), review available data on the in vivo evaluation of receptor systems by means of PET or SPECT for identifying and monitoring patients with sufficient receptor overexpression for tailored therapeutic interventions, and also for depicting tumor tissue and determining the currently largely unknown heterogeneity in receptor expression among different tumor lesions within and between patients. PET can be used to image and quantify the in vivo distribution of positron-emitting radioisotopes such as oxygen-15, carbon-11, and fluorine-18 that can be substituted or added into biologically relevant and specific receptor radioligands. Similarly, SPECT can be used to image and quantify the in vivo distribution of receptor targeting compounds labeled with indium-111, technetium-99m, and iodine-123. By virtue of their whole-body imaging capacity and the absence of errors of sampling and tissue manipulation as well as preparation, both techniques have the potential to address locoregional receptor status noninvasively and repetitively.
The following patents and patent application publications, which describe gamma cameras and imaging processing techniques, and which are incorporated herein by reference, may be of interest:
US Patent Application Publication 2005/0205792 to Rousso et al.
PCT Publication WO 05/118659 to Dicbterman et al.
PCT Publication WO 05/119025 to Nagler et al.
US Patent Application Publication 2004/0204646 to Nagler et al.
PCT Publication WO 06/054296 to Dickman
PCT Publication WO 04/042546 to Kimchy et al.
US Patent Application Publication 2004/0054248 to Kimchy et al.
US Patent Application Publication 2004/0015075 to Kimchy et al.
US Patent Application Publication 2004/0054278 to Kimchy et al.
US Patent Application Publication 2005/0266074 to Zilberstein et al.
U.S. Pat. Nos. 5,939,724, 5,587,585, and 5,365,069 to Eisen et al.
U.S. Pat. No. 6,943,355 to Shwartz et al.
U.S. Pat. No. 5,757,006 to DeVito et al.
U.S. Pat. No. 6,137,109 to Hayes
U.S. Pat. No. 6,398,258 to Berlad et al.
U.S. Pat. No. 6,429,431 to Wilk
U.S. Pat. No. 6,838,672 to Wagenaar et al.
U.S. Pat. Nos. 6,740,882, 6,545,280, 6,229,145, 5,519,221, 5,252,830, and 6,628,984 to Weinberg
U.S. Pat. No. 6,713,766 to Garrard et al.
U.S. Pat. No. 6,765,981 to Heumann
U.S. Pat. No. 6,664,542 to Ye et al.
U.S. Pat. No. 6,080,984 to Friesenhahn
U.S. Pat. No. 5,818,050 to Dilmanian et al.
U.S. Pat. No. 6,728,583 to Hallett
U.S. Pat. No. 5,481,115 to Hsieh et al.
U.S. Pat. No. 6,723,988 to Wainer
U.S. Pat. No. 6,940,070 to Tumer
U.S. Pat. No. 6,635,879 to Jimbo et al.
U.S. Pat. No. 6,353,227 to Boxen
U.S. Pat. No. 6,184,530 to Hines et al.
US Patent Application Publication 2005/0145797 to Oaknin et al.
US Patent Application Publication 2004/0251419 to Nelson et al.
US Patent Application Publication 2003/0001098 to Stoddart et al.
PCT Publication WO 98/16852 to DeVito et al.
PCT Publication WO 05/059840 to Nielsen et al.
U.S. Pat. No. 5,813,985 to Carroll
U.S. Pat. No. 6,455,043 to Grillo-Lopez
The following articles, all of which are incorporated herein by reference, may be of interest:
Yao D et al., "The utility of monoclonal antibodies in the imaging of prostate cancer," Semin Urol Oncol 20(3):211-8 (2002)
van der Laken C J et al., "Technetium-99m-labeled chemotactic peptides in acute infection and sterile inflammation," J Nucl Med 38(8):1310-5 (1997)    Babich J W et al., "Localization of radiolabeled chemotactic peptide at focal sites of Escherichia coli infection in rabbits: evidence for a receptor-specific mechanism," J Nucl Med 38(8):1316-22 (1997)
Rao P S et al., "99mTc-peptide-peptide nucleic acid probes for imaging oncogene mRNAs in tumours," Nuclear Medicine Communications 24(8):857-863 (2003)
Fischman A J et al., "Infection imaging with technetium-99m-labeled chemotactic peptide analogs," Semin Nucl Med 24(2):154-68 (1994)
Massoud T F et al., "Molecular imaging in living subjects: seeing fundamental biological processes in a new light," Genes & Development 17:545-580 (2003)
Gambhir S. S, "Molecular imaging of cancer with positron emission tomography," Nature Reviews 2:683-693 (2002).

Radiopharmaceuticals for diagnosis and therapy


A procedure for texturing an object of a virtual three-dimensional geometric model represented by three-dimensional geometric model data comprised of a three-dimensional object data associated with the object. Facet data is created out of three-dimensional geometric model data representing object surfaces of an object and which will be assigned 3D object data. Texture data is created representing a surface texture of the object surfaces of each object and which is assigned facet data. The three-dimensional object data, facet data and texture data are used to create a textured, three-dimensional representation of the object.

In addition to triangle based rendering, texturing is a fundamental computer graphic operation. Texture data are generally represented as 2 or 3 dimensional raster or volume data. Computer graphic models being textured require texture coordinates, which are either defined explicitly as part of a model description (texture coordinates for each corner of a geometric model), implicitly from the model geometry, for example two-dimensional surface parameterization, or procedurally, for example in the case of projective textures. The texturing data utilized in the texturizing process are either of a synthetic or a photographic nature. Data of different origin can be combined as well. Spatially localized image data as created in the capture of aerial pictures, for example, can be prepared for texturizing by manually or semi automatically cutting out image sections and afterward equalizing them in regard to perspective and geometry.

Procedure and device for the texturizing of an object of a virtual three-dimensional geometric model


A clock generating apparatus includes: a time-to-digital converter (TDC) arranged to convert a timing difference between a reference clock and a variable clock to generate a digital value; a calibrating device arranged to generate a control signal according to the digital value and the reference clock; a controllable oscillator arranged to generate an oscillating signal according to the control signal and the digital value; and a feedback device arranged to generate the variable clock to the TDC according to the oscillating signal, and the calibrating device calibrates the controllable oscillator to make the oscillating signal have a target oscillating frequency.

The present invention relates to a clock generating apparatus and a frequency calibrating method of the clock generating apparatus, and more particularly to a phase-locked loop applied in a multi-standard communication system having a short frequency calibrating time, and a method thereof.
In a wireless communication system, a phase-locked loop is utilized to generate a clock signal having a predetermined oscillating frequency to accommodate a specific communications standard. The phase-locked loop is designed to be able to generate different oscillating frequencies corresponding to different communications standards respectively. The frequency tuning range of an oscillator in the phase-locked loop should therefore be wide enough to accommodate the multi-communications standards. Conventionally, when a wireless communication system is to be operated under a specific communications standard, the oscillator is first controlled to search over the whole usable frequency range in order to calibrate the oscillator for outputting a target frequency corresponding to the specific communications standard. The conventional communication system may require a long time to search the target frequency when more and more communications standards are embedded into one wireless communication system. Therefore, speeding up the calibrating time of a phase-locked loop to generate the target frequency in a multi-standard communications system has become an important issue in the field.

Clock generating apparatus and frequency calibrating method of the clock generating apparatus


A monolithic weighing system including a base (12), a load holder (26), which is articulated on the base (12) through a parallel link arrangement (16, 20), and a lever (28), which is articulated on the load holder (26) and which has an attachment point for a force compensating arrangement and a target area (32) for an optical position sensor (34). The target area (32) has a slotted diaphragm (36) in a thin walled lever section of the lever (28) in the deflection plane thereof. A position sensor pedestal (38a, b), which is integrally connected to the base (12), is arranged laterally adjacent to the target area (32). The position sensor pedestal has a pedestal aperture (40a, b), which extends perpendicularly to the deflection plane. The slotted diaphragm (36) of the target area (32) is laser-machined through the pedestal aperture (40a, b).

Monolithic weighing systems as the core element of weighing devices are known to the person skilled in this art from precision balances, in particular, from precision balances that work on the principle of electromagnetic force compensation. Weighing systems of this type have a load holder, which is articulated on a base by a parallel link arrangement. In the resulting precision balance the load holder is connected to a weighing pan that holds samples to be weighed, whereas the base is fixed in position. The load holder is able to perform a strictly vertical motion, at least in the event of small deflections, due to the parallel link arrangement. A lever arrangement for transmitting the deflection of the load holder is articulated on the load holder. The lever arrangement is provided with an attachment point for a force compensating arrangement, for example, an electromagnetic moving coil arrangement. The force compensating arrangement is used to generate a counter force that acts on the lever arrangement and that compensates for the deflection of the lever arrangement, where the deflection is produced by the force of gravity acting on the load holder. In the event that the force compensating arrangement is designed as an electromagnetic moving coil arrangement, it is necessary to control a current through the moving coil in order to compensate for the force. The corresponding control circuit includes an optical position sensor that accurately detects the deflections of the lever arrangement, and the electronic control unit provides a corresponding signal, so that an immediate compensation can take place. With this approach it is possible to achieve the objective that the actual deflections of the lever arrangement can be minimized. To some extent it is referred to as a "path-free" force compensation.
The sensitivity of the position sensor is essential for precision weighing. In commercially available weighing systems the lever arrangement has a slotted diaphragm, which is monitored by an optical sensor, in a section of the lever that is designed as a thin wall and that is subject to a comparatively large deflection, in the plane of deflection. In particular, it has proven to be useful to arrange a slotted diaphragm of a thin walled lever section between a photo emitter and a photo detector, so that the light of the photo emitter transilluminates the slotted diaphragm on its way to the photo detector. In the event that the photo detector is suitably design as, for example, a split photodiode, the deflections of the lever section bearing the slotted diaphragm can be very accurately registered. For this purpose pedestals for mounting the photo emitter and the photo detector are required on both sides of the target area, i.e., the slotted diaphragm.
DE 37 43 073 A1 discloses a balance, in which the transmitter and the receiver of the optical position sensor are accommodated inside the magnet cover. Furthermore, U.S. Pat. No. 3,805,907 discloses a null-type indicator for a balance, in which for purposes of adjustment the light sensitive areas can be pivoted about the optical axis of the receiver.
For reasons relating to mechanical precision and repeatability, weighing systems of this type are manufactured, as far as possible, in a monolithic manner. That is, they are machined from a uniform block of material, such as aluminum. However, in the aforementioned weighing systems known from the prior art, the pedestals for mounting the position sensor can be manufactured separately and then subsequently screwed to the base. For reasons relating to precision, in particular the position sensor has to be positioned very close to the target area. However, the resulting spatial constraint does not allow the slotted diaphragm of the target area to be cut out with the milling and drilling tools that are used to make the rest of the monolith. On the other hand, however, the monolithic attachment of the position sensor pedestals would be especially important with respect to the primary goal of increasing the resolution and repeatability in the weighing area. Due to the limited repeatability of the position of the position sensor relative to the slotted diaphragm that can be achieved with existing manufacturing methods, the net result is, in particular, assembly inaccuracies and effects, such as temperature effects on the threaded connections.


The present invention relates to a solid-state relay including a power semiconductor switch device connected between a first electrical terminal and a second electrical terminal and having a command terminal. An electronic driving block is adapted to generate a command signal applied to the command terminal to switch the at least one semiconductor switch device from a closed/open state to an open/closed state to disconnect/connect the first electrical circuit portion from/to the second portion of the electrical circuit. An electronic block detects a current which crosses the power semiconductor switch device. The electronic detection block includes a first electronic device adapted to generate a first signal indicative of a difference of potential between the first and second terminals generated by the current which crosses a total resistance present between the first and second terminals of the power semiconductor switch device in the closed state. The total resistance comprises the sum of a first resistance associated with the semiconductor switch device in the closed state and of second bonding resistances associated with an electrical connection between one of the conductive terminals and the respective either first or second electrical terminal.

1. Field of the Invention
The present invention relates to electrically actuated switching devices or relays. In particular, the invention relates to a solid-state relay electrically actuated to open/close an electrical circuit in response to a control signal to disconnect/connect a first portion of an electrical circuit from/to a second portion of such a circuit. Particularly, but in a non-limiting manner, the invention relates to an electronic solid-state relay which can be used to electrically disconnect/connect an electric charge storage device or battery for electric or hybrid traction motor vehicles from/to a load.
2. Description of the Related Art
In applications in the automotive field, in particular in electric or hybrid traction vehicles, each motor vehicle is equipped with a source of electric charge or electric charge storage device or battery adapted to store the electrical energy used also for traction. Movement system for an electric or hybrid vehicle typically includes a loading assembly, in particular an electric motor adapted to generate the motion, driven by an inverter, which is electrically connected to a battery pack or assembly for storing the electrical energy. In particular, the electrical connection between the inverter and the battery pack is achieved by a direct current (DC) bus, generally referred to as DC-BUS or HV DC BUS by those skilled in the art.
The battery pack particularly comprises an electrochemical cell block adapted to supply the desired voltage and capacitance to the terminals of the direct current bus. The battery pack cells can be electrically disconnected from the loading assembly by the isolation devices, in particular relays.
In the automotive field, it is known to construct such relays by electromechanical devices, in particular for high currents, controlled by a Battery Management System or BMS, generally housed inside the battery pack itself. Such electromechanical relay devices for high currents used in the automotive field are not free from drawbacks.
Indeed, such relays have a large, heavy structure, comprising moving mechanical parts, which increases the size and overall weight of the battery system with which they are associated. Moreover, the presence of moving mechanical parts which are subject to deterioration over time or particular operating working conditions, such as for example the opening of the relay itself in the presence of high currents, could reduce the lifespan of the relay with respect to the working life of the battery.
Moreover, detecting the current which crosses the electromechanical relay when this is in the closed state is often needed in the movement system of an electric or hybrid traction vehicle. For such a purpose, such a system comprises a current measuring sensor implemented, for example, by a shunt resistor or a Hall effect sensor, associated with the direct current bus and controlled by the Battery Management System BMS. Such a sensor is an additional element of the system which further complicates the structure thereof.

Solid-state relay including an electronic current detection block


A system and method for predictive analysis includes generating an execution trace on an instrumented version of source code for a multithreaded computer program. Interleavings which potentially lead to a violation in the program are statically generated by performing a static predictive analysis using a Universal Causality Graph (UCG) to generate alternative interleavings that might lead to an error. The UCG includes a unified happens-before model for the concurrent program and a property being analyzed. The interleavings are symbolically checked to determine errors in the program.

1. Technical Field
The present invention relates to computer program checking and more particularly to a system and method for analyzing a concurrent program with predictive analysis which employs a Universal Causality Graph (UCG).
2. Description of the Related Art
Predictive analysis aims at detecting concurrency errors such as atomicity violations by analyzing a concrete execution trace (which itself may be non-erroneous). In its most general form, predictive analysis has three main steps: 1) Run a test of the concurrent program to obtain an execution trace. 2) Run a sound but over-approximate algorithm, typically involving statically analyzing the given trace, to detect all potential violations, e.g., data races, deadlocks, atomicity violations, etc. If no violation is found, return. 3) Build the precise predictive model, and for each potential violation, check whether it is feasible. If it is feasible, create a concrete and replayable witness trace. This check is typically formulated as a satisfiability problem, by constructing a formula which is satisfiable if there exists a feasible trace that exposes a potential error.
In this framework, step 2, i.e., a static enumeration of the set of interleavings that may potentially lead to a concurrency violation, occupies a key role in determining scalability as well as precision of the overall procedure.
Existing predictive analysis algorithms can be classified into the following categories: 1) Methods that do not miss real errors but may report bogus errors. These methods are based on over approximated modeling of the execution trace. Representatives are based on causal atomicity, and based on type-for-atomicity. 2) Methods that do not report bogus errors but may miss some real errors. These methods are based on under-approximated modeling. Representatives are based on happens-before causality relations. 3) Methods that are both sound and complete but not scalable as they explore too many interleavings.

Universal causality graphs for bug detection in concurrent programs


A tracked vehicle has a chassis including a tunnel. An engine is connected to the chassis. An endless drive track is disposed below the tunnel and operatively connected to the engine. A suspension assembly supports and tensions the endless drive track. The suspension assembly has a longitudinal direction and a lateral direction. The suspension assembly includes a rail engaging the endless drive track. The rail extends in the longitudinal direction. A suspension arm has an upper end pivotally connected to the chassis about a first lateral axis, and a lower end pivotally connected to the rail about a second lateral axis. At least one shock absorber is connected between the chassis and the rail for biasing the rail away from the chassis. The chassis is pivotally connected to the rail via the suspension assembly about a longitudinally extending axis. A suspension assembly is also disclosed.

Irregularities in the terrain over which a tracked vehicle (such as a snowmobile) travels produce displacements and deflections of its suspension assembly. A conventional suspension supports an endless track, which is tensioned to surround a pair of parallel slide rails, a plurality of idler wheels and at least one drive wheel or sprocket. A shock absorbing mechanism involving springs, hydraulic dampers, and/or other shock absorbing elements, urges the slide frame assembly and the chassis (also known as a frame) of the tracked vehicle apart, against the weight supported above the suspension in a static condition.
When an irregularity such as a bump occurs on the terrain, the suspension allows the slide rails to move toward the tunnel. Similarly, when a depression occurs on the terrain, the suspension allows the slide rails to move away from the tunnel. In some cases, the terrain provides configurations for which the current tracked vehicles (and snowmobiles in particular) cannot or can only minimally accommodate. This is the case, for example, when the tracked vehicle is side-hilling. A tracked vehicle is said to be side-hilling when it is positioned at least partially sideways on a slope. In such a position, an uphill part of the suspension is disposed vertically above a downhill part of the suspension. This can increase the resistance to lean the tracked vehicle into the slope to keep the tracked vehicle horizontal.
Therefore, there is a need for a suspension assembly for a tracked vehicle that allows the tracked vehicle to drive on different terrain configurations. There is also a need for a tracked vehicle having such a suspension.